May 2025 - Linux-stable-mirror

FAILED: patch "[PATCH] selftests/mm: compaction_test: support platform with huge" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x ab00ddd802f80e31fc9639c652d736fe3913feae # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051246-book-chase-1d4c@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From ab00ddd802f80e31fc9639c652d736fe3913feae Mon Sep 17 00:00:00 2001 From: Feng Tang <feng.tang(a)linux.alibaba.com> Date: Wed, 23 Apr 2025 18:36:45 +0800 Subject: [PATCH] selftests/mm: compaction_test: support platform with huge mount of memory When running mm selftest to verify mm patches, 'compaction_test' case failed on an x86 server with 1TB memory. And the root cause is that it has too much free memory than what the test supports. The test case tries to allocate 100000 huge pages, which is about 200 GB for that x86 server, and when it succeeds, it expects it's large than 1/3 of 80% of the free memory in system. This logic only works for platform with 750 GB ( 200 / (1/3) / 80% ) or less free memory, and may raise false alarm for others. Fix it by changing the fixed page number to self-adjustable number according to the real number of free memory. Link: https://lkml.kernel.org/r/20250423103645.2758-1-feng.tang@linux.alibaba.com Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory") Signed-off-by: Feng Tang <feng.tang(a)linux.alibaba.com> Acked-by: Dev Jain <dev.jain(a)arm.com> Reviewed-by: Baolin Wang <baolin.wang(a)linux.alibaba.com> Tested-by: Baolin Wang <baolin.wang(a)inux.alibaba.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Sri Jayaramappa <sjayaram(a)akamai.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c index 2c3a0eb6b22d..9bc4591c7b16 100644 --- a/tools/testing/selftests/mm/compaction_test.c +++ b/tools/testing/selftests/mm/compaction_test.c @@ -90,6 +90,8 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size, int compaction_index = 0; char nr_hugepages[20] = {0}; char init_nr_hugepages[24] = {0}; + char target_nr_hugepages[24] = {0}; + int slen; snprintf(init_nr_hugepages, sizeof(init_nr_hugepages), "%lu", initial_nr_hugepages); @@ -106,11 +108,18 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size, goto out; } - /* Request a large number of huge pages. The Kernel will allocate - as much as it can */ - if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) { - ksft_print_msg("Failed to write 100000 to /proc/sys/vm/nr_hugepages: %s\n", - strerror(errno)); + /* + * Request huge pages for about half of the free memory. The Kernel + * will allocate as much as it can, and we expect it will get at least 1/3 + */ + nr_hugepages_ul = mem_free / hugepage_size / 2; + snprintf(target_nr_hugepages, sizeof(target_nr_hugepages), + "%lu", nr_hugepages_ul); + + slen = strlen(target_nr_hugepages); + if (write(fd, target_nr_hugepages, slen) != slen) { + ksft_print_msg("Failed to write %lu to /proc/sys/vm/nr_hugepages: %s\n", + nr_hugepages_ul, strerror(errno)); goto close_fd; }

4 months, 1 week

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0 0

FAILED: patch "[PATCH] mm/userfaultfd: fix uninitialized output field for -EAGAIN" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 95567729173e62e0e60a1f8ad9eb2e1320a8ccac # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051236-dense-economy-c808@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 95567729173e62e0e60a1f8ad9eb2e1320a8ccac Mon Sep 17 00:00:00 2001 From: Peter Xu <peterx(a)redhat.com> Date: Thu, 24 Apr 2025 17:57:28 -0400 Subject: [PATCH] mm/userfaultfd: fix uninitialized output field for -EAGAIN race While discussing some userfaultfd relevant issues recently, Andrea noticed a potential ABI breakage with -EAGAIN on almost all userfaultfd ioctl()s. Quote from Andrea, explaining how -EAGAIN was processed, and how this should fix it (taking example of UFFDIO_COPY ioctl): The "mmap_changing" and "stale pmd" conditions are already reported as -EAGAIN written in the copy field, this does not change it. This change removes the subnormal case that left copy.copy uninitialized and required apps to explicitly set the copy field to get deterministic behavior (which is a requirement contrary to the documentation in both the manpage and source code). In turn there's no alteration to backwards compatibility as result of this change because userland will find the copy field consistently set to -EAGAIN, and not anymore sometime -EAGAIN and sometime uninitialized. Even then the change only can make a difference to non cooperative users of userfaultfd, so when UFFD_FEATURE_EVENT_* is enabled, which is not true for the vast majority of apps using userfaultfd or this unintended uninitialized field may have been noticed sooner. Meanwhile, since this bug existed for years, it also almost affects all ioctl()s that was introduced later. Besides UFFDIO_ZEROPAGE, these also get affected in the same way: - UFFDIO_CONTINUE - UFFDIO_POISON - UFFDIO_MOVE This patch should have fixed all of them. Link: https://lkml.kernel.org/r/20250424215729.194656-2-peterx@redhat.com Fixes: df2cc96e7701 ("userfaultfd: prevent non-cooperative events vs mcopy_atomic races") Fixes: f619147104c8 ("userfaultfd: add UFFDIO_CONTINUE ioctl") Fixes: fc71884a5f59 ("mm: userfaultfd: add new UFFDIO_POISON ioctl") Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Peter Xu <peterx(a)redhat.com> Reported-by: Andrea Arcangeli <aarcange(a)redhat.com> Suggested-by: Andrea Arcangeli <aarcange(a)redhat.com> Reviewed-by: David Hildenbrand <david(a)redhat.com> Cc: Mike Rapoport <rppt(a)kernel.org> Cc: Axel Rasmussen <axelrasmussen(a)google.com> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index d80f94346199..22f4bf956ba1 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1585,8 +1585,11 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx, user_uffdio_copy = (struct uffdio_copy __user *) arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_copy->copy))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_copy, user_uffdio_copy, @@ -1641,8 +1644,11 @@ static int userfaultfd_zeropage(struct userfaultfd_ctx *ctx, user_uffdio_zeropage = (struct uffdio_zeropage __user *) arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_zeropage->zeropage))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_zeropage, user_uffdio_zeropage, @@ -1744,8 +1750,11 @@ static int userfaultfd_continue(struct userfaultfd_ctx *ctx, unsigned long arg) user_uffdio_continue = (struct uffdio_continue __user *)arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_continue->mapped))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_continue, user_uffdio_continue, @@ -1801,8 +1810,11 @@ static inline int userfaultfd_poison(struct userfaultfd_ctx *ctx, unsigned long user_uffdio_poison = (struct uffdio_poison __user *)arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_poison->updated))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_poison, user_uffdio_poison, @@ -1870,8 +1882,12 @@ static int userfaultfd_move(struct userfaultfd_ctx *ctx, user_uffdio_move = (struct uffdio_move __user *) arg; - if (atomic_read(&ctx->mmap_changing)) - return -EAGAIN; + ret = -EAGAIN; + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_move->move))) + return -EFAULT; + goto out; + } if (copy_from_user(&uffdio_move, user_uffdio_move, /* don't copy "move" last field */

4 months, 1 week

1
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0 0

FAILED: patch "[PATCH] mm/userfaultfd: fix uninitialized output field for -EAGAIN" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 95567729173e62e0e60a1f8ad9eb2e1320a8ccac # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051235-unusual-viewer-d8fa@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 95567729173e62e0e60a1f8ad9eb2e1320a8ccac Mon Sep 17 00:00:00 2001 From: Peter Xu <peterx(a)redhat.com> Date: Thu, 24 Apr 2025 17:57:28 -0400 Subject: [PATCH] mm/userfaultfd: fix uninitialized output field for -EAGAIN race While discussing some userfaultfd relevant issues recently, Andrea noticed a potential ABI breakage with -EAGAIN on almost all userfaultfd ioctl()s. Quote from Andrea, explaining how -EAGAIN was processed, and how this should fix it (taking example of UFFDIO_COPY ioctl): The "mmap_changing" and "stale pmd" conditions are already reported as -EAGAIN written in the copy field, this does not change it. This change removes the subnormal case that left copy.copy uninitialized and required apps to explicitly set the copy field to get deterministic behavior (which is a requirement contrary to the documentation in both the manpage and source code). In turn there's no alteration to backwards compatibility as result of this change because userland will find the copy field consistently set to -EAGAIN, and not anymore sometime -EAGAIN and sometime uninitialized. Even then the change only can make a difference to non cooperative users of userfaultfd, so when UFFD_FEATURE_EVENT_* is enabled, which is not true for the vast majority of apps using userfaultfd or this unintended uninitialized field may have been noticed sooner. Meanwhile, since this bug existed for years, it also almost affects all ioctl()s that was introduced later. Besides UFFDIO_ZEROPAGE, these also get affected in the same way: - UFFDIO_CONTINUE - UFFDIO_POISON - UFFDIO_MOVE This patch should have fixed all of them. Link: https://lkml.kernel.org/r/20250424215729.194656-2-peterx@redhat.com Fixes: df2cc96e7701 ("userfaultfd: prevent non-cooperative events vs mcopy_atomic races") Fixes: f619147104c8 ("userfaultfd: add UFFDIO_CONTINUE ioctl") Fixes: fc71884a5f59 ("mm: userfaultfd: add new UFFDIO_POISON ioctl") Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Peter Xu <peterx(a)redhat.com> Reported-by: Andrea Arcangeli <aarcange(a)redhat.com> Suggested-by: Andrea Arcangeli <aarcange(a)redhat.com> Reviewed-by: David Hildenbrand <david(a)redhat.com> Cc: Mike Rapoport <rppt(a)kernel.org> Cc: Axel Rasmussen <axelrasmussen(a)google.com> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index d80f94346199..22f4bf956ba1 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1585,8 +1585,11 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx, user_uffdio_copy = (struct uffdio_copy __user *) arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_copy->copy))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_copy, user_uffdio_copy, @@ -1641,8 +1644,11 @@ static int userfaultfd_zeropage(struct userfaultfd_ctx *ctx, user_uffdio_zeropage = (struct uffdio_zeropage __user *) arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_zeropage->zeropage))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_zeropage, user_uffdio_zeropage, @@ -1744,8 +1750,11 @@ static int userfaultfd_continue(struct userfaultfd_ctx *ctx, unsigned long arg) user_uffdio_continue = (struct uffdio_continue __user *)arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_continue->mapped))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_continue, user_uffdio_continue, @@ -1801,8 +1810,11 @@ static inline int userfaultfd_poison(struct userfaultfd_ctx *ctx, unsigned long user_uffdio_poison = (struct uffdio_poison __user *)arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_poison->updated))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_poison, user_uffdio_poison, @@ -1870,8 +1882,12 @@ static int userfaultfd_move(struct userfaultfd_ctx *ctx, user_uffdio_move = (struct uffdio_move __user *) arg; - if (atomic_read(&ctx->mmap_changing)) - return -EAGAIN; + ret = -EAGAIN; + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_move->move))) + return -EFAULT; + goto out; + } if (copy_from_user(&uffdio_move, user_uffdio_move, /* don't copy "move" last field */

4 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] mm/userfaultfd: fix uninitialized output field for -EAGAIN" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 95567729173e62e0e60a1f8ad9eb2e1320a8ccac # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051234-legwarmer-usable-d2c7@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 95567729173e62e0e60a1f8ad9eb2e1320a8ccac Mon Sep 17 00:00:00 2001 From: Peter Xu <peterx(a)redhat.com> Date: Thu, 24 Apr 2025 17:57:28 -0400 Subject: [PATCH] mm/userfaultfd: fix uninitialized output field for -EAGAIN race While discussing some userfaultfd relevant issues recently, Andrea noticed a potential ABI breakage with -EAGAIN on almost all userfaultfd ioctl()s. Quote from Andrea, explaining how -EAGAIN was processed, and how this should fix it (taking example of UFFDIO_COPY ioctl): The "mmap_changing" and "stale pmd" conditions are already reported as -EAGAIN written in the copy field, this does not change it. This change removes the subnormal case that left copy.copy uninitialized and required apps to explicitly set the copy field to get deterministic behavior (which is a requirement contrary to the documentation in both the manpage and source code). In turn there's no alteration to backwards compatibility as result of this change because userland will find the copy field consistently set to -EAGAIN, and not anymore sometime -EAGAIN and sometime uninitialized. Even then the change only can make a difference to non cooperative users of userfaultfd, so when UFFD_FEATURE_EVENT_* is enabled, which is not true for the vast majority of apps using userfaultfd or this unintended uninitialized field may have been noticed sooner. Meanwhile, since this bug existed for years, it also almost affects all ioctl()s that was introduced later. Besides UFFDIO_ZEROPAGE, these also get affected in the same way: - UFFDIO_CONTINUE - UFFDIO_POISON - UFFDIO_MOVE This patch should have fixed all of them. Link: https://lkml.kernel.org/r/20250424215729.194656-2-peterx@redhat.com Fixes: df2cc96e7701 ("userfaultfd: prevent non-cooperative events vs mcopy_atomic races") Fixes: f619147104c8 ("userfaultfd: add UFFDIO_CONTINUE ioctl") Fixes: fc71884a5f59 ("mm: userfaultfd: add new UFFDIO_POISON ioctl") Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Peter Xu <peterx(a)redhat.com> Reported-by: Andrea Arcangeli <aarcange(a)redhat.com> Suggested-by: Andrea Arcangeli <aarcange(a)redhat.com> Reviewed-by: David Hildenbrand <david(a)redhat.com> Cc: Mike Rapoport <rppt(a)kernel.org> Cc: Axel Rasmussen <axelrasmussen(a)google.com> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index d80f94346199..22f4bf956ba1 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1585,8 +1585,11 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx, user_uffdio_copy = (struct uffdio_copy __user *) arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_copy->copy))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_copy, user_uffdio_copy, @@ -1641,8 +1644,11 @@ static int userfaultfd_zeropage(struct userfaultfd_ctx *ctx, user_uffdio_zeropage = (struct uffdio_zeropage __user *) arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_zeropage->zeropage))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_zeropage, user_uffdio_zeropage, @@ -1744,8 +1750,11 @@ static int userfaultfd_continue(struct userfaultfd_ctx *ctx, unsigned long arg) user_uffdio_continue = (struct uffdio_continue __user *)arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_continue->mapped))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_continue, user_uffdio_continue, @@ -1801,8 +1810,11 @@ static inline int userfaultfd_poison(struct userfaultfd_ctx *ctx, unsigned long user_uffdio_poison = (struct uffdio_poison __user *)arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_poison->updated))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_poison, user_uffdio_poison, @@ -1870,8 +1882,12 @@ static int userfaultfd_move(struct userfaultfd_ctx *ctx, user_uffdio_move = (struct uffdio_move __user *) arg; - if (atomic_read(&ctx->mmap_changing)) - return -EAGAIN; + ret = -EAGAIN; + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_move->move))) + return -EFAULT; + goto out; + } if (copy_from_user(&uffdio_move, user_uffdio_move, /* don't copy "move" last field */

4 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] mm/userfaultfd: fix uninitialized output field for -EAGAIN" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 95567729173e62e0e60a1f8ad9eb2e1320a8ccac # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051228-laurel-hypnoses-428f@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 95567729173e62e0e60a1f8ad9eb2e1320a8ccac Mon Sep 17 00:00:00 2001 From: Peter Xu <peterx(a)redhat.com> Date: Thu, 24 Apr 2025 17:57:28 -0400 Subject: [PATCH] mm/userfaultfd: fix uninitialized output field for -EAGAIN race While discussing some userfaultfd relevant issues recently, Andrea noticed a potential ABI breakage with -EAGAIN on almost all userfaultfd ioctl()s. Quote from Andrea, explaining how -EAGAIN was processed, and how this should fix it (taking example of UFFDIO_COPY ioctl): The "mmap_changing" and "stale pmd" conditions are already reported as -EAGAIN written in the copy field, this does not change it. This change removes the subnormal case that left copy.copy uninitialized and required apps to explicitly set the copy field to get deterministic behavior (which is a requirement contrary to the documentation in both the manpage and source code). In turn there's no alteration to backwards compatibility as result of this change because userland will find the copy field consistently set to -EAGAIN, and not anymore sometime -EAGAIN and sometime uninitialized. Even then the change only can make a difference to non cooperative users of userfaultfd, so when UFFD_FEATURE_EVENT_* is enabled, which is not true for the vast majority of apps using userfaultfd or this unintended uninitialized field may have been noticed sooner. Meanwhile, since this bug existed for years, it also almost affects all ioctl()s that was introduced later. Besides UFFDIO_ZEROPAGE, these also get affected in the same way: - UFFDIO_CONTINUE - UFFDIO_POISON - UFFDIO_MOVE This patch should have fixed all of them. Link: https://lkml.kernel.org/r/20250424215729.194656-2-peterx@redhat.com Fixes: df2cc96e7701 ("userfaultfd: prevent non-cooperative events vs mcopy_atomic races") Fixes: f619147104c8 ("userfaultfd: add UFFDIO_CONTINUE ioctl") Fixes: fc71884a5f59 ("mm: userfaultfd: add new UFFDIO_POISON ioctl") Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Peter Xu <peterx(a)redhat.com> Reported-by: Andrea Arcangeli <aarcange(a)redhat.com> Suggested-by: Andrea Arcangeli <aarcange(a)redhat.com> Reviewed-by: David Hildenbrand <david(a)redhat.com> Cc: Mike Rapoport <rppt(a)kernel.org> Cc: Axel Rasmussen <axelrasmussen(a)google.com> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index d80f94346199..22f4bf956ba1 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1585,8 +1585,11 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx, user_uffdio_copy = (struct uffdio_copy __user *) arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_copy->copy))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_copy, user_uffdio_copy, @@ -1641,8 +1644,11 @@ static int userfaultfd_zeropage(struct userfaultfd_ctx *ctx, user_uffdio_zeropage = (struct uffdio_zeropage __user *) arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_zeropage->zeropage))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_zeropage, user_uffdio_zeropage, @@ -1744,8 +1750,11 @@ static int userfaultfd_continue(struct userfaultfd_ctx *ctx, unsigned long arg) user_uffdio_continue = (struct uffdio_continue __user *)arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_continue->mapped))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_continue, user_uffdio_continue, @@ -1801,8 +1810,11 @@ static inline int userfaultfd_poison(struct userfaultfd_ctx *ctx, unsigned long user_uffdio_poison = (struct uffdio_poison __user *)arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_poison->updated))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_poison, user_uffdio_poison, @@ -1870,8 +1882,12 @@ static int userfaultfd_move(struct userfaultfd_ctx *ctx, user_uffdio_move = (struct uffdio_move __user *) arg; - if (atomic_read(&ctx->mmap_changing)) - return -EAGAIN; + ret = -EAGAIN; + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_move->move))) + return -EFAULT; + goto out; + } if (copy_from_user(&uffdio_move, user_uffdio_move, /* don't copy "move" last field */

4 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] mm/userfaultfd: fix uninitialized output field for -EAGAIN" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 95567729173e62e0e60a1f8ad9eb2e1320a8ccac # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051227-malt-universe-29e7@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 95567729173e62e0e60a1f8ad9eb2e1320a8ccac Mon Sep 17 00:00:00 2001 From: Peter Xu <peterx(a)redhat.com> Date: Thu, 24 Apr 2025 17:57:28 -0400 Subject: [PATCH] mm/userfaultfd: fix uninitialized output field for -EAGAIN race While discussing some userfaultfd relevant issues recently, Andrea noticed a potential ABI breakage with -EAGAIN on almost all userfaultfd ioctl()s. Quote from Andrea, explaining how -EAGAIN was processed, and how this should fix it (taking example of UFFDIO_COPY ioctl): The "mmap_changing" and "stale pmd" conditions are already reported as -EAGAIN written in the copy field, this does not change it. This change removes the subnormal case that left copy.copy uninitialized and required apps to explicitly set the copy field to get deterministic behavior (which is a requirement contrary to the documentation in both the manpage and source code). In turn there's no alteration to backwards compatibility as result of this change because userland will find the copy field consistently set to -EAGAIN, and not anymore sometime -EAGAIN and sometime uninitialized. Even then the change only can make a difference to non cooperative users of userfaultfd, so when UFFD_FEATURE_EVENT_* is enabled, which is not true for the vast majority of apps using userfaultfd or this unintended uninitialized field may have been noticed sooner. Meanwhile, since this bug existed for years, it also almost affects all ioctl()s that was introduced later. Besides UFFDIO_ZEROPAGE, these also get affected in the same way: - UFFDIO_CONTINUE - UFFDIO_POISON - UFFDIO_MOVE This patch should have fixed all of them. Link: https://lkml.kernel.org/r/20250424215729.194656-2-peterx@redhat.com Fixes: df2cc96e7701 ("userfaultfd: prevent non-cooperative events vs mcopy_atomic races") Fixes: f619147104c8 ("userfaultfd: add UFFDIO_CONTINUE ioctl") Fixes: fc71884a5f59 ("mm: userfaultfd: add new UFFDIO_POISON ioctl") Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Peter Xu <peterx(a)redhat.com> Reported-by: Andrea Arcangeli <aarcange(a)redhat.com> Suggested-by: Andrea Arcangeli <aarcange(a)redhat.com> Reviewed-by: David Hildenbrand <david(a)redhat.com> Cc: Mike Rapoport <rppt(a)kernel.org> Cc: Axel Rasmussen <axelrasmussen(a)google.com> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index d80f94346199..22f4bf956ba1 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1585,8 +1585,11 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx, user_uffdio_copy = (struct uffdio_copy __user *) arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_copy->copy))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_copy, user_uffdio_copy, @@ -1641,8 +1644,11 @@ static int userfaultfd_zeropage(struct userfaultfd_ctx *ctx, user_uffdio_zeropage = (struct uffdio_zeropage __user *) arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_zeropage->zeropage))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_zeropage, user_uffdio_zeropage, @@ -1744,8 +1750,11 @@ static int userfaultfd_continue(struct userfaultfd_ctx *ctx, unsigned long arg) user_uffdio_continue = (struct uffdio_continue __user *)arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_continue->mapped))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_continue, user_uffdio_continue, @@ -1801,8 +1810,11 @@ static inline int userfaultfd_poison(struct userfaultfd_ctx *ctx, unsigned long user_uffdio_poison = (struct uffdio_poison __user *)arg; ret = -EAGAIN; - if (atomic_read(&ctx->mmap_changing)) + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_poison->updated))) + return -EFAULT; goto out; + } ret = -EFAULT; if (copy_from_user(&uffdio_poison, user_uffdio_poison, @@ -1870,8 +1882,12 @@ static int userfaultfd_move(struct userfaultfd_ctx *ctx, user_uffdio_move = (struct uffdio_move __user *) arg; - if (atomic_read(&ctx->mmap_changing)) - return -EAGAIN; + ret = -EAGAIN; + if (unlikely(atomic_read(&ctx->mmap_changing))) { + if (unlikely(put_user(ret, &user_uffdio_move->move))) + return -EFAULT; + goto out; + } if (copy_from_user(&uffdio_move, user_uffdio_move, /* don't copy "move" last field */

4 months, 1 week

1
0
0 0

Re: Patch "s390/entry: Fix last breaking event handling in case of stack corruption" has been added to the 6.6-stable tree

by Heiko Carstens

On Sun, May 11, 2025 at 01:59:02PM -0400, Sasha Levin wrote: > This is a note to let you know that I've just added the patch titled > > s390/entry: Fix last breaking event handling in case of stack corruption > > to the 6.6-stable tree which can be found at: > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… > > The filename of the patch is: > s390-entry-fix-last-breaking-event-handling-in-case-.patch > and it can be found in the queue-6.6 subdirectory. > > If you, or anyone else, feels it should not be added to the stable tree, > please let <stable(a)vger.kernel.org> know about it. This patch shouldn't be applied as it is to 6.6, 6.1, and 5.15 stable kernels, since it won't compile. I'll provide a slightly modified variant.

4 months, 1 week

2
1
0 0

FAILED: patch "[PATCH] staging: axis-fifo: Correct handling of tx_fifo_depth for" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 2ca34b508774aaa590fc3698a54204706ecca4ba # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051209-visible-hassle-6995@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 2ca34b508774aaa590fc3698a54204706ecca4ba Mon Sep 17 00:00:00 2001 From: Gabriel Shahrouzi <gshahrouzi(a)gmail.com> Date: Fri, 18 Apr 2025 21:29:37 -0400 Subject: [PATCH] staging: axis-fifo: Correct handling of tx_fifo_depth for size validation Remove erroneous subtraction of 4 from the total FIFO depth read from device tree. The stored depth is for checking against total capacity, not initial vacancy. This prevented writes near the FIFO's full size. The check performed just before data transfer, which uses live reads of the TDFV register to determine current vacancy, correctly handles the initial Depth - 4 hardware state and subsequent FIFO fullness. Fixes: 4a965c5f89de ("staging: add driver for Xilinx AXI-Stream FIFO v4.1 IP core") Cc: stable(a)vger.kernel.org Signed-off-by: Gabriel Shahrouzi <gshahrouzi(a)gmail.com> Link: https://lore.kernel.org/r/20250419012937.674924-1-gshahrouzi@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c index 7540c20090c7..04b3dc3cfe7c 100644 --- a/drivers/staging/axis-fifo/axis-fifo.c +++ b/drivers/staging/axis-fifo/axis-fifo.c @@ -775,9 +775,6 @@ static int axis_fifo_parse_dt(struct axis_fifo *fifo) goto end; } - /* IP sets TDFV to fifo depth - 4 so we will do the same */ - fifo->tx_fifo_depth -= 4; - ret = get_dts_property(fifo, "xlnx,use-rx-data", &fifo->has_rx_fifo); if (ret) { dev_err(fifo->dt_device, "missing xlnx,use-rx-data property\n");

4 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] staging: axis-fifo: Remove hardware resets for user errors" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x c6e8d85fafa7193613db37da29c0e8d6e2515b13 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051251-pardon-stellar-d13f@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From c6e8d85fafa7193613db37da29c0e8d6e2515b13 Mon Sep 17 00:00:00 2001 From: Gabriel Shahrouzi <gshahrouzi(a)gmail.com> Date: Fri, 18 Apr 2025 20:43:06 -0400 Subject: [PATCH] staging: axis-fifo: Remove hardware resets for user errors The axis-fifo driver performs a full hardware reset (via reset_ip_core()) in several error paths within the read and write functions. This reset flushes both TX and RX FIFOs and resets the AXI-Stream links. Allow the user to handle the error without causing hardware disruption or data loss in other FIFO paths. Fixes: 4a965c5f89de ("staging: add driver for Xilinx AXI-Stream FIFO v4.1 IP core") Cc: stable(a)vger.kernel.org Signed-off-by: Gabriel Shahrouzi <gshahrouzi(a)gmail.com> Link: https://lore.kernel.org/r/20250419004306.669605-1-gshahrouzi@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c index 04b3dc3cfe7c..351f983ef914 100644 --- a/drivers/staging/axis-fifo/axis-fifo.c +++ b/drivers/staging/axis-fifo/axis-fifo.c @@ -393,16 +393,14 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf, bytes_available = ioread32(fifo->base_addr + XLLF_RLR_OFFSET); if (!bytes_available) { - dev_err(fifo->dt_device, "received a packet of length 0 - fifo core will be reset\n"); - reset_ip_core(fifo); + dev_err(fifo->dt_device, "received a packet of length 0\n"); ret = -EIO; goto end_unlock; } if (bytes_available > len) { - dev_err(fifo->dt_device, "user read buffer too small (available bytes=%zu user buffer bytes=%zu) - fifo core will be reset\n", + dev_err(fifo->dt_device, "user read buffer too small (available bytes=%zu user buffer bytes=%zu)\n", bytes_available, len); - reset_ip_core(fifo); ret = -EINVAL; goto end_unlock; } @@ -411,8 +409,7 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf, /* this probably can't happen unless IP * registers were previously mishandled */ - dev_err(fifo->dt_device, "received a packet that isn't word-aligned - fifo core will be reset\n"); - reset_ip_core(fifo); + dev_err(fifo->dt_device, "received a packet that isn't word-aligned\n"); ret = -EIO; goto end_unlock; } @@ -433,7 +430,6 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf, if (copy_to_user(buf + copied * sizeof(u32), tmp_buf, copy * sizeof(u32))) { - reset_ip_core(fifo); ret = -EFAULT; goto end_unlock; } @@ -542,7 +538,6 @@ static ssize_t axis_fifo_write(struct file *f, const char __user *buf, if (copy_from_user(tmp_buf, buf + copied * sizeof(u32), copy * sizeof(u32))) { - reset_ip_core(fifo); ret = -EFAULT; goto end_unlock; }

4 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] uio_hv_generic: Fix sysfs creation path for ring buffer" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x f31fe8165d365379d858c53bef43254c7d6d1cfd # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051213-regretful-conceded-2379@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f31fe8165d365379d858c53bef43254c7d6d1cfd Mon Sep 17 00:00:00 2001 From: Naman Jain <namjain(a)linux.microsoft.com> Date: Fri, 2 May 2025 13:18:10 +0530 Subject: [PATCH] uio_hv_generic: Fix sysfs creation path for ring buffer On regular bootup, devices get registered to VMBus first, so when uio_hv_generic driver for a particular device type is probed, the device is already initialized and added, so sysfs creation in hv_uio_probe() works fine. However, when the device is removed and brought back, the channel gets rescinded and the device again gets registered to VMBus. However this time, the uio_hv_generic driver is already registered to probe for that device and in this case sysfs creation is tried before the device's kobject gets initialized completely. Fix this by moving the core logic of sysfs creation of ring buffer, from uio_hv_generic to HyperV's VMBus driver, where the rest of the sysfs attributes for the channels are defined. While doing that, make use of attribute groups and macros, instead of creating sysfs directly, to ensure better error handling and code flow. Problematic path: vmbus_process_offer (A new offer comes for the VMBus device) vmbus_add_channel_work vmbus_device_register |-> device_register | |... | |-> hv_uio_probe | |... | |-> sysfs_create_bin_file (leads to a warning as | the primary channel's kobject, which is used to | create the sysfs file, is not yet initialized) |-> kset_create_and_add |-> vmbus_add_channel_kobj (initialization of the primary channel's kobject happens later) Above code flow is sequential and the warning is always reproducible in this path. Fixes: 9ab877a6ccf8 ("uio_hv_generic: make ring buffer attribute for primary channel") Cc: stable(a)kernel.org Suggested-by: Saurabh Sengar <ssengar(a)linux.microsoft.com> Suggested-by: Michael Kelley <mhklinux(a)outlook.com> Reviewed-by: Michael Kelley <mhklinux(a)outlook.com> Tested-by: Michael Kelley <mhklinux(a)outlook.com> Reviewed-by: Dexuan Cui <decui(a)microsoft.com> Signed-off-by: Naman Jain <namjain(a)linux.microsoft.com> Link: https://lore.kernel.org/r/20250502074811.2022-2-namjain@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 29780f3a7478..0b450e53161e 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -477,4 +477,10 @@ static inline int hv_debug_add_dev_dir(struct hv_device *dev) #endif /* CONFIG_HYPERV_TESTING */ +/* Create and remove sysfs entry for memory mapped ring buffers for a channel */ +int hv_create_ring_sysfs(struct vmbus_channel *channel, + int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel, + struct vm_area_struct *vma)); +int hv_remove_ring_sysfs(struct vmbus_channel *channel); + #endif /* _HYPERV_VMBUS_H */ diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 8d3cff42bdbb..0f16a83cc2d6 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1802,6 +1802,27 @@ static ssize_t subchannel_id_show(struct vmbus_channel *channel, } static VMBUS_CHAN_ATTR_RO(subchannel_id); +static int hv_mmap_ring_buffer_wrapper(struct file *filp, struct kobject *kobj, + const struct bin_attribute *attr, + struct vm_area_struct *vma) +{ + struct vmbus_channel *channel = container_of(kobj, struct vmbus_channel, kobj); + + /* + * hv_(create|remove)_ring_sysfs implementation ensures that mmap_ring_buffer + * is not NULL. + */ + return channel->mmap_ring_buffer(channel, vma); +} + +static struct bin_attribute chan_attr_ring_buffer = { + .attr = { + .name = "ring", + .mode = 0600, + }, + .size = 2 * SZ_2M, + .mmap = hv_mmap_ring_buffer_wrapper, +}; static struct attribute *vmbus_chan_attrs[] = { &chan_attr_out_mask.attr, &chan_attr_in_mask.attr, @@ -1821,6 +1842,11 @@ static struct attribute *vmbus_chan_attrs[] = { NULL }; +static struct bin_attribute *vmbus_chan_bin_attrs[] = { + &chan_attr_ring_buffer, + NULL +}; + /* * Channel-level attribute_group callback function. Returns the permission for * each attribute, and returns 0 if an attribute is not visible. @@ -1841,9 +1867,24 @@ static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj, return attr->mode; } +static umode_t vmbus_chan_bin_attr_is_visible(struct kobject *kobj, + const struct bin_attribute *attr, int idx) +{ + const struct vmbus_channel *channel = + container_of(kobj, struct vmbus_channel, kobj); + + /* Hide ring attribute if channel's ring_sysfs_visible is set to false */ + if (attr == &chan_attr_ring_buffer && !channel->ring_sysfs_visible) + return 0; + + return attr->attr.mode; +} + static const struct attribute_group vmbus_chan_group = { .attrs = vmbus_chan_attrs, - .is_visible = vmbus_chan_attr_is_visible + .bin_attrs = vmbus_chan_bin_attrs, + .is_visible = vmbus_chan_attr_is_visible, + .is_bin_visible = vmbus_chan_bin_attr_is_visible, }; static const struct kobj_type vmbus_chan_ktype = { @@ -1851,6 +1892,63 @@ static const struct kobj_type vmbus_chan_ktype = { .release = vmbus_chan_release, }; +/** + * hv_create_ring_sysfs() - create "ring" sysfs entry corresponding to ring buffers for a channel. + * @channel: Pointer to vmbus_channel structure + * @hv_mmap_ring_buffer: function pointer for initializing the function to be called on mmap of + * channel's "ring" sysfs node, which is for the ring buffer of that channel. + * Function pointer is of below type: + * int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel, + * struct vm_area_struct *vma)) + * This has a pointer to the channel and a pointer to vm_area_struct, + * used for mmap, as arguments. + * + * Sysfs node for ring buffer of a channel is created along with other fields, however its + * visibility is disabled by default. Sysfs creation needs to be controlled when the use-case + * is running. + * For example, HV_NIC device is used either by uio_hv_generic or hv_netvsc at any given point of + * time, and "ring" sysfs is needed only when uio_hv_generic is bound to that device. To avoid + * exposing the ring buffer by default, this function is reponsible to enable visibility of + * ring for userspace to use. + * Note: Race conditions can happen with userspace and it is not encouraged to create new + * use-cases for this. This was added to maintain backward compatibility, while solving + * one of the race conditions in uio_hv_generic while creating sysfs. + * + * Returns 0 on success or error code on failure. + */ +int hv_create_ring_sysfs(struct vmbus_channel *channel, + int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel, + struct vm_area_struct *vma)) +{ + struct kobject *kobj = &channel->kobj; + + channel->mmap_ring_buffer = hv_mmap_ring_buffer; + channel->ring_sysfs_visible = true; + + return sysfs_update_group(kobj, &vmbus_chan_group); +} +EXPORT_SYMBOL_GPL(hv_create_ring_sysfs); + +/** + * hv_remove_ring_sysfs() - remove ring sysfs entry corresponding to ring buffers for a channel. + * @channel: Pointer to vmbus_channel structure + * + * Hide "ring" sysfs for a channel by changing its is_visible attribute and updating sysfs group. + * + * Returns 0 on success or error code on failure. + */ +int hv_remove_ring_sysfs(struct vmbus_channel *channel) +{ + struct kobject *kobj = &channel->kobj; + int ret; + + channel->ring_sysfs_visible = false; + ret = sysfs_update_group(kobj, &vmbus_chan_group); + channel->mmap_ring_buffer = NULL; + return ret; +} +EXPORT_SYMBOL_GPL(hv_remove_ring_sysfs); + /* * vmbus_add_channel_kobj - setup a sub-directory under device/channels */ diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c index 1b19b5647495..69c1df0f4ca5 100644 --- a/drivers/uio/uio_hv_generic.c +++ b/drivers/uio/uio_hv_generic.c @@ -131,15 +131,12 @@ static void hv_uio_rescind(struct vmbus_channel *channel) vmbus_device_unregister(channel->device_obj); } -/* Sysfs API to allow mmap of the ring buffers +/* Function used for mmap of ring buffer sysfs interface. * The ring buffer is allocated as contiguous memory by vmbus_open */ -static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj, - const struct bin_attribute *attr, - struct vm_area_struct *vma) +static int +hv_uio_ring_mmap(struct vmbus_channel *channel, struct vm_area_struct *vma) { - struct vmbus_channel *channel - = container_of(kobj, struct vmbus_channel, kobj); void *ring_buffer = page_address(channel->ringbuffer_page); if (channel->state != CHANNEL_OPENED_STATE) @@ -149,15 +146,6 @@ static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj, channel->ringbuffer_pagecount << PAGE_SHIFT); } -static const struct bin_attribute ring_buffer_bin_attr = { - .attr = { - .name = "ring", - .mode = 0600, - }, - .size = 2 * SZ_2M, - .mmap = hv_uio_ring_mmap, -}; - /* Callback from VMBUS subsystem when new channel created. */ static void hv_uio_new_channel(struct vmbus_channel *new_sc) @@ -178,8 +166,7 @@ hv_uio_new_channel(struct vmbus_channel *new_sc) /* Disable interrupts on sub channel */ new_sc->inbound.ring_buffer->interrupt_mask = 1; set_channel_read_mode(new_sc, HV_CALL_ISR); - - ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr); + ret = hv_create_ring_sysfs(new_sc, hv_uio_ring_mmap); if (ret) { dev_err(device, "sysfs create ring bin file failed; %d\n", ret); vmbus_close(new_sc); @@ -350,10 +337,18 @@ hv_uio_probe(struct hv_device *dev, goto fail_close; } - ret = sysfs_create_bin_file(&channel->kobj, &ring_buffer_bin_attr); - if (ret) - dev_notice(&dev->device, - "sysfs create ring bin file failed; %d\n", ret); + /* + * This internally calls sysfs_update_group, which returns a non-zero value if it executes + * before sysfs_create_group. This is expected as the 'ring' will be created later in + * vmbus_device_register() -> vmbus_add_channel_kobj(). Thus, no need to check the return + * value and print warning. + * + * Creating/exposing sysfs in driver probe is not encouraged as it can lead to race + * conditions with userspace. For backward compatibility, "ring" sysfs could not be removed + * or decoupled from uio_hv_generic probe. Userspace programs can make use of inotify + * APIs to make sure that ring is created. + */ + hv_create_ring_sysfs(channel, hv_uio_ring_mmap); hv_set_drvdata(dev, pdata); @@ -375,7 +370,7 @@ hv_uio_remove(struct hv_device *dev) if (!pdata) return; - sysfs_remove_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr); + hv_remove_ring_sysfs(dev->channel); uio_unregister_device(&pdata->info); hv_uio_cleanup(dev, pdata); diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 675959fb97ba..d6ffe01962c2 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1002,6 +1002,12 @@ struct vmbus_channel { /* The max size of a packet on this channel */ u32 max_pkt_size; + + /* function to mmap ring buffer memory to the channel's sysfs ring attribute */ + int (*mmap_ring_buffer)(struct vmbus_channel *channel, struct vm_area_struct *vma); + + /* boolean to control visibility of sysfs for ring buffer */ + bool ring_sysfs_visible; }; #define lock_requestor(channel, flags) \

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FAILED: patch "[PATCH] uio_hv_generic: Fix sysfs creation path for ring buffer" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x f31fe8165d365379d858c53bef43254c7d6d1cfd # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051212-blah-famine-0e8e@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f31fe8165d365379d858c53bef43254c7d6d1cfd Mon Sep 17 00:00:00 2001 From: Naman Jain <namjain(a)linux.microsoft.com> Date: Fri, 2 May 2025 13:18:10 +0530 Subject: [PATCH] uio_hv_generic: Fix sysfs creation path for ring buffer On regular bootup, devices get registered to VMBus first, so when uio_hv_generic driver for a particular device type is probed, the device is already initialized and added, so sysfs creation in hv_uio_probe() works fine. However, when the device is removed and brought back, the channel gets rescinded and the device again gets registered to VMBus. However this time, the uio_hv_generic driver is already registered to probe for that device and in this case sysfs creation is tried before the device's kobject gets initialized completely. Fix this by moving the core logic of sysfs creation of ring buffer, from uio_hv_generic to HyperV's VMBus driver, where the rest of the sysfs attributes for the channels are defined. While doing that, make use of attribute groups and macros, instead of creating sysfs directly, to ensure better error handling and code flow. Problematic path: vmbus_process_offer (A new offer comes for the VMBus device) vmbus_add_channel_work vmbus_device_register |-> device_register | |... | |-> hv_uio_probe | |... | |-> sysfs_create_bin_file (leads to a warning as | the primary channel's kobject, which is used to | create the sysfs file, is not yet initialized) |-> kset_create_and_add |-> vmbus_add_channel_kobj (initialization of the primary channel's kobject happens later) Above code flow is sequential and the warning is always reproducible in this path. Fixes: 9ab877a6ccf8 ("uio_hv_generic: make ring buffer attribute for primary channel") Cc: stable(a)kernel.org Suggested-by: Saurabh Sengar <ssengar(a)linux.microsoft.com> Suggested-by: Michael Kelley <mhklinux(a)outlook.com> Reviewed-by: Michael Kelley <mhklinux(a)outlook.com> Tested-by: Michael Kelley <mhklinux(a)outlook.com> Reviewed-by: Dexuan Cui <decui(a)microsoft.com> Signed-off-by: Naman Jain <namjain(a)linux.microsoft.com> Link: https://lore.kernel.org/r/20250502074811.2022-2-namjain@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 29780f3a7478..0b450e53161e 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -477,4 +477,10 @@ static inline int hv_debug_add_dev_dir(struct hv_device *dev) #endif /* CONFIG_HYPERV_TESTING */ +/* Create and remove sysfs entry for memory mapped ring buffers for a channel */ +int hv_create_ring_sysfs(struct vmbus_channel *channel, + int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel, + struct vm_area_struct *vma)); +int hv_remove_ring_sysfs(struct vmbus_channel *channel); + #endif /* _HYPERV_VMBUS_H */ diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 8d3cff42bdbb..0f16a83cc2d6 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1802,6 +1802,27 @@ static ssize_t subchannel_id_show(struct vmbus_channel *channel, } static VMBUS_CHAN_ATTR_RO(subchannel_id); +static int hv_mmap_ring_buffer_wrapper(struct file *filp, struct kobject *kobj, + const struct bin_attribute *attr, + struct vm_area_struct *vma) +{ + struct vmbus_channel *channel = container_of(kobj, struct vmbus_channel, kobj); + + /* + * hv_(create|remove)_ring_sysfs implementation ensures that mmap_ring_buffer + * is not NULL. + */ + return channel->mmap_ring_buffer(channel, vma); +} + +static struct bin_attribute chan_attr_ring_buffer = { + .attr = { + .name = "ring", + .mode = 0600, + }, + .size = 2 * SZ_2M, + .mmap = hv_mmap_ring_buffer_wrapper, +}; static struct attribute *vmbus_chan_attrs[] = { &chan_attr_out_mask.attr, &chan_attr_in_mask.attr, @@ -1821,6 +1842,11 @@ static struct attribute *vmbus_chan_attrs[] = { NULL }; +static struct bin_attribute *vmbus_chan_bin_attrs[] = { + &chan_attr_ring_buffer, + NULL +}; + /* * Channel-level attribute_group callback function. Returns the permission for * each attribute, and returns 0 if an attribute is not visible. @@ -1841,9 +1867,24 @@ static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj, return attr->mode; } +static umode_t vmbus_chan_bin_attr_is_visible(struct kobject *kobj, + const struct bin_attribute *attr, int idx) +{ + const struct vmbus_channel *channel = + container_of(kobj, struct vmbus_channel, kobj); + + /* Hide ring attribute if channel's ring_sysfs_visible is set to false */ + if (attr == &chan_attr_ring_buffer && !channel->ring_sysfs_visible) + return 0; + + return attr->attr.mode; +} + static const struct attribute_group vmbus_chan_group = { .attrs = vmbus_chan_attrs, - .is_visible = vmbus_chan_attr_is_visible + .bin_attrs = vmbus_chan_bin_attrs, + .is_visible = vmbus_chan_attr_is_visible, + .is_bin_visible = vmbus_chan_bin_attr_is_visible, }; static const struct kobj_type vmbus_chan_ktype = { @@ -1851,6 +1892,63 @@ static const struct kobj_type vmbus_chan_ktype = { .release = vmbus_chan_release, }; +/** + * hv_create_ring_sysfs() - create "ring" sysfs entry corresponding to ring buffers for a channel. + * @channel: Pointer to vmbus_channel structure + * @hv_mmap_ring_buffer: function pointer for initializing the function to be called on mmap of + * channel's "ring" sysfs node, which is for the ring buffer of that channel. + * Function pointer is of below type: + * int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel, + * struct vm_area_struct *vma)) + * This has a pointer to the channel and a pointer to vm_area_struct, + * used for mmap, as arguments. + * + * Sysfs node for ring buffer of a channel is created along with other fields, however its + * visibility is disabled by default. Sysfs creation needs to be controlled when the use-case + * is running. + * For example, HV_NIC device is used either by uio_hv_generic or hv_netvsc at any given point of + * time, and "ring" sysfs is needed only when uio_hv_generic is bound to that device. To avoid + * exposing the ring buffer by default, this function is reponsible to enable visibility of + * ring for userspace to use. + * Note: Race conditions can happen with userspace and it is not encouraged to create new + * use-cases for this. This was added to maintain backward compatibility, while solving + * one of the race conditions in uio_hv_generic while creating sysfs. + * + * Returns 0 on success or error code on failure. + */ +int hv_create_ring_sysfs(struct vmbus_channel *channel, + int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel, + struct vm_area_struct *vma)) +{ + struct kobject *kobj = &channel->kobj; + + channel->mmap_ring_buffer = hv_mmap_ring_buffer; + channel->ring_sysfs_visible = true; + + return sysfs_update_group(kobj, &vmbus_chan_group); +} +EXPORT_SYMBOL_GPL(hv_create_ring_sysfs); + +/** + * hv_remove_ring_sysfs() - remove ring sysfs entry corresponding to ring buffers for a channel. + * @channel: Pointer to vmbus_channel structure + * + * Hide "ring" sysfs for a channel by changing its is_visible attribute and updating sysfs group. + * + * Returns 0 on success or error code on failure. + */ +int hv_remove_ring_sysfs(struct vmbus_channel *channel) +{ + struct kobject *kobj = &channel->kobj; + int ret; + + channel->ring_sysfs_visible = false; + ret = sysfs_update_group(kobj, &vmbus_chan_group); + channel->mmap_ring_buffer = NULL; + return ret; +} +EXPORT_SYMBOL_GPL(hv_remove_ring_sysfs); + /* * vmbus_add_channel_kobj - setup a sub-directory under device/channels */ diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c index 1b19b5647495..69c1df0f4ca5 100644 --- a/drivers/uio/uio_hv_generic.c +++ b/drivers/uio/uio_hv_generic.c @@ -131,15 +131,12 @@ static void hv_uio_rescind(struct vmbus_channel *channel) vmbus_device_unregister(channel->device_obj); } -/* Sysfs API to allow mmap of the ring buffers +/* Function used for mmap of ring buffer sysfs interface. * The ring buffer is allocated as contiguous memory by vmbus_open */ -static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj, - const struct bin_attribute *attr, - struct vm_area_struct *vma) +static int +hv_uio_ring_mmap(struct vmbus_channel *channel, struct vm_area_struct *vma) { - struct vmbus_channel *channel - = container_of(kobj, struct vmbus_channel, kobj); void *ring_buffer = page_address(channel->ringbuffer_page); if (channel->state != CHANNEL_OPENED_STATE) @@ -149,15 +146,6 @@ static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj, channel->ringbuffer_pagecount << PAGE_SHIFT); } -static const struct bin_attribute ring_buffer_bin_attr = { - .attr = { - .name = "ring", - .mode = 0600, - }, - .size = 2 * SZ_2M, - .mmap = hv_uio_ring_mmap, -}; - /* Callback from VMBUS subsystem when new channel created. */ static void hv_uio_new_channel(struct vmbus_channel *new_sc) @@ -178,8 +166,7 @@ hv_uio_new_channel(struct vmbus_channel *new_sc) /* Disable interrupts on sub channel */ new_sc->inbound.ring_buffer->interrupt_mask = 1; set_channel_read_mode(new_sc, HV_CALL_ISR); - - ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr); + ret = hv_create_ring_sysfs(new_sc, hv_uio_ring_mmap); if (ret) { dev_err(device, "sysfs create ring bin file failed; %d\n", ret); vmbus_close(new_sc); @@ -350,10 +337,18 @@ hv_uio_probe(struct hv_device *dev, goto fail_close; } - ret = sysfs_create_bin_file(&channel->kobj, &ring_buffer_bin_attr); - if (ret) - dev_notice(&dev->device, - "sysfs create ring bin file failed; %d\n", ret); + /* + * This internally calls sysfs_update_group, which returns a non-zero value if it executes + * before sysfs_create_group. This is expected as the 'ring' will be created later in + * vmbus_device_register() -> vmbus_add_channel_kobj(). Thus, no need to check the return + * value and print warning. + * + * Creating/exposing sysfs in driver probe is not encouraged as it can lead to race + * conditions with userspace. For backward compatibility, "ring" sysfs could not be removed + * or decoupled from uio_hv_generic probe. Userspace programs can make use of inotify + * APIs to make sure that ring is created. + */ + hv_create_ring_sysfs(channel, hv_uio_ring_mmap); hv_set_drvdata(dev, pdata); @@ -375,7 +370,7 @@ hv_uio_remove(struct hv_device *dev) if (!pdata) return; - sysfs_remove_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr); + hv_remove_ring_sysfs(dev->channel); uio_unregister_device(&pdata->info); hv_uio_cleanup(dev, pdata); diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 675959fb97ba..d6ffe01962c2 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1002,6 +1002,12 @@ struct vmbus_channel { /* The max size of a packet on this channel */ u32 max_pkt_size; + + /* function to mmap ring buffer memory to the channel's sysfs ring attribute */ + int (*mmap_ring_buffer)(struct vmbus_channel *channel, struct vm_area_struct *vma); + + /* boolean to control visibility of sysfs for ring buffer */ + bool ring_sysfs_visible; }; #define lock_requestor(channel, flags) \

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FAILED: patch "[PATCH] uio_hv_generic: Fix sysfs creation path for ring buffer" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x f31fe8165d365379d858c53bef43254c7d6d1cfd # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051211-renewably-acclimate-72f0@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f31fe8165d365379d858c53bef43254c7d6d1cfd Mon Sep 17 00:00:00 2001 From: Naman Jain <namjain(a)linux.microsoft.com> Date: Fri, 2 May 2025 13:18:10 +0530 Subject: [PATCH] uio_hv_generic: Fix sysfs creation path for ring buffer On regular bootup, devices get registered to VMBus first, so when uio_hv_generic driver for a particular device type is probed, the device is already initialized and added, so sysfs creation in hv_uio_probe() works fine. However, when the device is removed and brought back, the channel gets rescinded and the device again gets registered to VMBus. However this time, the uio_hv_generic driver is already registered to probe for that device and in this case sysfs creation is tried before the device's kobject gets initialized completely. Fix this by moving the core logic of sysfs creation of ring buffer, from uio_hv_generic to HyperV's VMBus driver, where the rest of the sysfs attributes for the channels are defined. While doing that, make use of attribute groups and macros, instead of creating sysfs directly, to ensure better error handling and code flow. Problematic path: vmbus_process_offer (A new offer comes for the VMBus device) vmbus_add_channel_work vmbus_device_register |-> device_register | |... | |-> hv_uio_probe | |... | |-> sysfs_create_bin_file (leads to a warning as | the primary channel's kobject, which is used to | create the sysfs file, is not yet initialized) |-> kset_create_and_add |-> vmbus_add_channel_kobj (initialization of the primary channel's kobject happens later) Above code flow is sequential and the warning is always reproducible in this path. Fixes: 9ab877a6ccf8 ("uio_hv_generic: make ring buffer attribute for primary channel") Cc: stable(a)kernel.org Suggested-by: Saurabh Sengar <ssengar(a)linux.microsoft.com> Suggested-by: Michael Kelley <mhklinux(a)outlook.com> Reviewed-by: Michael Kelley <mhklinux(a)outlook.com> Tested-by: Michael Kelley <mhklinux(a)outlook.com> Reviewed-by: Dexuan Cui <decui(a)microsoft.com> Signed-off-by: Naman Jain <namjain(a)linux.microsoft.com> Link: https://lore.kernel.org/r/20250502074811.2022-2-namjain@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 29780f3a7478..0b450e53161e 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -477,4 +477,10 @@ static inline int hv_debug_add_dev_dir(struct hv_device *dev) #endif /* CONFIG_HYPERV_TESTING */ +/* Create and remove sysfs entry for memory mapped ring buffers for a channel */ +int hv_create_ring_sysfs(struct vmbus_channel *channel, + int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel, + struct vm_area_struct *vma)); +int hv_remove_ring_sysfs(struct vmbus_channel *channel); + #endif /* _HYPERV_VMBUS_H */ diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 8d3cff42bdbb..0f16a83cc2d6 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1802,6 +1802,27 @@ static ssize_t subchannel_id_show(struct vmbus_channel *channel, } static VMBUS_CHAN_ATTR_RO(subchannel_id); +static int hv_mmap_ring_buffer_wrapper(struct file *filp, struct kobject *kobj, + const struct bin_attribute *attr, + struct vm_area_struct *vma) +{ + struct vmbus_channel *channel = container_of(kobj, struct vmbus_channel, kobj); + + /* + * hv_(create|remove)_ring_sysfs implementation ensures that mmap_ring_buffer + * is not NULL. + */ + return channel->mmap_ring_buffer(channel, vma); +} + +static struct bin_attribute chan_attr_ring_buffer = { + .attr = { + .name = "ring", + .mode = 0600, + }, + .size = 2 * SZ_2M, + .mmap = hv_mmap_ring_buffer_wrapper, +}; static struct attribute *vmbus_chan_attrs[] = { &chan_attr_out_mask.attr, &chan_attr_in_mask.attr, @@ -1821,6 +1842,11 @@ static struct attribute *vmbus_chan_attrs[] = { NULL }; +static struct bin_attribute *vmbus_chan_bin_attrs[] = { + &chan_attr_ring_buffer, + NULL +}; + /* * Channel-level attribute_group callback function. Returns the permission for * each attribute, and returns 0 if an attribute is not visible. @@ -1841,9 +1867,24 @@ static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj, return attr->mode; } +static umode_t vmbus_chan_bin_attr_is_visible(struct kobject *kobj, + const struct bin_attribute *attr, int idx) +{ + const struct vmbus_channel *channel = + container_of(kobj, struct vmbus_channel, kobj); + + /* Hide ring attribute if channel's ring_sysfs_visible is set to false */ + if (attr == &chan_attr_ring_buffer && !channel->ring_sysfs_visible) + return 0; + + return attr->attr.mode; +} + static const struct attribute_group vmbus_chan_group = { .attrs = vmbus_chan_attrs, - .is_visible = vmbus_chan_attr_is_visible + .bin_attrs = vmbus_chan_bin_attrs, + .is_visible = vmbus_chan_attr_is_visible, + .is_bin_visible = vmbus_chan_bin_attr_is_visible, }; static const struct kobj_type vmbus_chan_ktype = { @@ -1851,6 +1892,63 @@ static const struct kobj_type vmbus_chan_ktype = { .release = vmbus_chan_release, }; +/** + * hv_create_ring_sysfs() - create "ring" sysfs entry corresponding to ring buffers for a channel. + * @channel: Pointer to vmbus_channel structure + * @hv_mmap_ring_buffer: function pointer for initializing the function to be called on mmap of + * channel's "ring" sysfs node, which is for the ring buffer of that channel. + * Function pointer is of below type: + * int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel, + * struct vm_area_struct *vma)) + * This has a pointer to the channel and a pointer to vm_area_struct, + * used for mmap, as arguments. + * + * Sysfs node for ring buffer of a channel is created along with other fields, however its + * visibility is disabled by default. Sysfs creation needs to be controlled when the use-case + * is running. + * For example, HV_NIC device is used either by uio_hv_generic or hv_netvsc at any given point of + * time, and "ring" sysfs is needed only when uio_hv_generic is bound to that device. To avoid + * exposing the ring buffer by default, this function is reponsible to enable visibility of + * ring for userspace to use. + * Note: Race conditions can happen with userspace and it is not encouraged to create new + * use-cases for this. This was added to maintain backward compatibility, while solving + * one of the race conditions in uio_hv_generic while creating sysfs. + * + * Returns 0 on success or error code on failure. + */ +int hv_create_ring_sysfs(struct vmbus_channel *channel, + int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel, + struct vm_area_struct *vma)) +{ + struct kobject *kobj = &channel->kobj; + + channel->mmap_ring_buffer = hv_mmap_ring_buffer; + channel->ring_sysfs_visible = true; + + return sysfs_update_group(kobj, &vmbus_chan_group); +} +EXPORT_SYMBOL_GPL(hv_create_ring_sysfs); + +/** + * hv_remove_ring_sysfs() - remove ring sysfs entry corresponding to ring buffers for a channel. + * @channel: Pointer to vmbus_channel structure + * + * Hide "ring" sysfs for a channel by changing its is_visible attribute and updating sysfs group. + * + * Returns 0 on success or error code on failure. + */ +int hv_remove_ring_sysfs(struct vmbus_channel *channel) +{ + struct kobject *kobj = &channel->kobj; + int ret; + + channel->ring_sysfs_visible = false; + ret = sysfs_update_group(kobj, &vmbus_chan_group); + channel->mmap_ring_buffer = NULL; + return ret; +} +EXPORT_SYMBOL_GPL(hv_remove_ring_sysfs); + /* * vmbus_add_channel_kobj - setup a sub-directory under device/channels */ diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c index 1b19b5647495..69c1df0f4ca5 100644 --- a/drivers/uio/uio_hv_generic.c +++ b/drivers/uio/uio_hv_generic.c @@ -131,15 +131,12 @@ static void hv_uio_rescind(struct vmbus_channel *channel) vmbus_device_unregister(channel->device_obj); } -/* Sysfs API to allow mmap of the ring buffers +/* Function used for mmap of ring buffer sysfs interface. * The ring buffer is allocated as contiguous memory by vmbus_open */ -static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj, - const struct bin_attribute *attr, - struct vm_area_struct *vma) +static int +hv_uio_ring_mmap(struct vmbus_channel *channel, struct vm_area_struct *vma) { - struct vmbus_channel *channel - = container_of(kobj, struct vmbus_channel, kobj); void *ring_buffer = page_address(channel->ringbuffer_page); if (channel->state != CHANNEL_OPENED_STATE) @@ -149,15 +146,6 @@ static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj, channel->ringbuffer_pagecount << PAGE_SHIFT); } -static const struct bin_attribute ring_buffer_bin_attr = { - .attr = { - .name = "ring", - .mode = 0600, - }, - .size = 2 * SZ_2M, - .mmap = hv_uio_ring_mmap, -}; - /* Callback from VMBUS subsystem when new channel created. */ static void hv_uio_new_channel(struct vmbus_channel *new_sc) @@ -178,8 +166,7 @@ hv_uio_new_channel(struct vmbus_channel *new_sc) /* Disable interrupts on sub channel */ new_sc->inbound.ring_buffer->interrupt_mask = 1; set_channel_read_mode(new_sc, HV_CALL_ISR); - - ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr); + ret = hv_create_ring_sysfs(new_sc, hv_uio_ring_mmap); if (ret) { dev_err(device, "sysfs create ring bin file failed; %d\n", ret); vmbus_close(new_sc); @@ -350,10 +337,18 @@ hv_uio_probe(struct hv_device *dev, goto fail_close; } - ret = sysfs_create_bin_file(&channel->kobj, &ring_buffer_bin_attr); - if (ret) - dev_notice(&dev->device, - "sysfs create ring bin file failed; %d\n", ret); + /* + * This internally calls sysfs_update_group, which returns a non-zero value if it executes + * before sysfs_create_group. This is expected as the 'ring' will be created later in + * vmbus_device_register() -> vmbus_add_channel_kobj(). Thus, no need to check the return + * value and print warning. + * + * Creating/exposing sysfs in driver probe is not encouraged as it can lead to race + * conditions with userspace. For backward compatibility, "ring" sysfs could not be removed + * or decoupled from uio_hv_generic probe. Userspace programs can make use of inotify + * APIs to make sure that ring is created. + */ + hv_create_ring_sysfs(channel, hv_uio_ring_mmap); hv_set_drvdata(dev, pdata); @@ -375,7 +370,7 @@ hv_uio_remove(struct hv_device *dev) if (!pdata) return; - sysfs_remove_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr); + hv_remove_ring_sysfs(dev->channel); uio_unregister_device(&pdata->info); hv_uio_cleanup(dev, pdata); diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 675959fb97ba..d6ffe01962c2 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1002,6 +1002,12 @@ struct vmbus_channel { /* The max size of a packet on this channel */ u32 max_pkt_size; + + /* function to mmap ring buffer memory to the channel's sysfs ring attribute */ + int (*mmap_ring_buffer)(struct vmbus_channel *channel, struct vm_area_struct *vma); + + /* boolean to control visibility of sysfs for ring buffer */ + bool ring_sysfs_visible; }; #define lock_requestor(channel, flags) \

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FAILED: patch "[PATCH] uio_hv_generic: Fix sysfs creation path for ring buffer" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x f31fe8165d365379d858c53bef43254c7d6d1cfd # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051210-wieldable-haunt-9fa2@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f31fe8165d365379d858c53bef43254c7d6d1cfd Mon Sep 17 00:00:00 2001 From: Naman Jain <namjain(a)linux.microsoft.com> Date: Fri, 2 May 2025 13:18:10 +0530 Subject: [PATCH] uio_hv_generic: Fix sysfs creation path for ring buffer On regular bootup, devices get registered to VMBus first, so when uio_hv_generic driver for a particular device type is probed, the device is already initialized and added, so sysfs creation in hv_uio_probe() works fine. However, when the device is removed and brought back, the channel gets rescinded and the device again gets registered to VMBus. However this time, the uio_hv_generic driver is already registered to probe for that device and in this case sysfs creation is tried before the device's kobject gets initialized completely. Fix this by moving the core logic of sysfs creation of ring buffer, from uio_hv_generic to HyperV's VMBus driver, where the rest of the sysfs attributes for the channels are defined. While doing that, make use of attribute groups and macros, instead of creating sysfs directly, to ensure better error handling and code flow. Problematic path: vmbus_process_offer (A new offer comes for the VMBus device) vmbus_add_channel_work vmbus_device_register |-> device_register | |... | |-> hv_uio_probe | |... | |-> sysfs_create_bin_file (leads to a warning as | the primary channel's kobject, which is used to | create the sysfs file, is not yet initialized) |-> kset_create_and_add |-> vmbus_add_channel_kobj (initialization of the primary channel's kobject happens later) Above code flow is sequential and the warning is always reproducible in this path. Fixes: 9ab877a6ccf8 ("uio_hv_generic: make ring buffer attribute for primary channel") Cc: stable(a)kernel.org Suggested-by: Saurabh Sengar <ssengar(a)linux.microsoft.com> Suggested-by: Michael Kelley <mhklinux(a)outlook.com> Reviewed-by: Michael Kelley <mhklinux(a)outlook.com> Tested-by: Michael Kelley <mhklinux(a)outlook.com> Reviewed-by: Dexuan Cui <decui(a)microsoft.com> Signed-off-by: Naman Jain <namjain(a)linux.microsoft.com> Link: https://lore.kernel.org/r/20250502074811.2022-2-namjain@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 29780f3a7478..0b450e53161e 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -477,4 +477,10 @@ static inline int hv_debug_add_dev_dir(struct hv_device *dev) #endif /* CONFIG_HYPERV_TESTING */ +/* Create and remove sysfs entry for memory mapped ring buffers for a channel */ +int hv_create_ring_sysfs(struct vmbus_channel *channel, + int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel, + struct vm_area_struct *vma)); +int hv_remove_ring_sysfs(struct vmbus_channel *channel); + #endif /* _HYPERV_VMBUS_H */ diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 8d3cff42bdbb..0f16a83cc2d6 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1802,6 +1802,27 @@ static ssize_t subchannel_id_show(struct vmbus_channel *channel, } static VMBUS_CHAN_ATTR_RO(subchannel_id); +static int hv_mmap_ring_buffer_wrapper(struct file *filp, struct kobject *kobj, + const struct bin_attribute *attr, + struct vm_area_struct *vma) +{ + struct vmbus_channel *channel = container_of(kobj, struct vmbus_channel, kobj); + + /* + * hv_(create|remove)_ring_sysfs implementation ensures that mmap_ring_buffer + * is not NULL. + */ + return channel->mmap_ring_buffer(channel, vma); +} + +static struct bin_attribute chan_attr_ring_buffer = { + .attr = { + .name = "ring", + .mode = 0600, + }, + .size = 2 * SZ_2M, + .mmap = hv_mmap_ring_buffer_wrapper, +}; static struct attribute *vmbus_chan_attrs[] = { &chan_attr_out_mask.attr, &chan_attr_in_mask.attr, @@ -1821,6 +1842,11 @@ static struct attribute *vmbus_chan_attrs[] = { NULL }; +static struct bin_attribute *vmbus_chan_bin_attrs[] = { + &chan_attr_ring_buffer, + NULL +}; + /* * Channel-level attribute_group callback function. Returns the permission for * each attribute, and returns 0 if an attribute is not visible. @@ -1841,9 +1867,24 @@ static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj, return attr->mode; } +static umode_t vmbus_chan_bin_attr_is_visible(struct kobject *kobj, + const struct bin_attribute *attr, int idx) +{ + const struct vmbus_channel *channel = + container_of(kobj, struct vmbus_channel, kobj); + + /* Hide ring attribute if channel's ring_sysfs_visible is set to false */ + if (attr == &chan_attr_ring_buffer && !channel->ring_sysfs_visible) + return 0; + + return attr->attr.mode; +} + static const struct attribute_group vmbus_chan_group = { .attrs = vmbus_chan_attrs, - .is_visible = vmbus_chan_attr_is_visible + .bin_attrs = vmbus_chan_bin_attrs, + .is_visible = vmbus_chan_attr_is_visible, + .is_bin_visible = vmbus_chan_bin_attr_is_visible, }; static const struct kobj_type vmbus_chan_ktype = { @@ -1851,6 +1892,63 @@ static const struct kobj_type vmbus_chan_ktype = { .release = vmbus_chan_release, }; +/** + * hv_create_ring_sysfs() - create "ring" sysfs entry corresponding to ring buffers for a channel. + * @channel: Pointer to vmbus_channel structure + * @hv_mmap_ring_buffer: function pointer for initializing the function to be called on mmap of + * channel's "ring" sysfs node, which is for the ring buffer of that channel. + * Function pointer is of below type: + * int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel, + * struct vm_area_struct *vma)) + * This has a pointer to the channel and a pointer to vm_area_struct, + * used for mmap, as arguments. + * + * Sysfs node for ring buffer of a channel is created along with other fields, however its + * visibility is disabled by default. Sysfs creation needs to be controlled when the use-case + * is running. + * For example, HV_NIC device is used either by uio_hv_generic or hv_netvsc at any given point of + * time, and "ring" sysfs is needed only when uio_hv_generic is bound to that device. To avoid + * exposing the ring buffer by default, this function is reponsible to enable visibility of + * ring for userspace to use. + * Note: Race conditions can happen with userspace and it is not encouraged to create new + * use-cases for this. This was added to maintain backward compatibility, while solving + * one of the race conditions in uio_hv_generic while creating sysfs. + * + * Returns 0 on success or error code on failure. + */ +int hv_create_ring_sysfs(struct vmbus_channel *channel, + int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel, + struct vm_area_struct *vma)) +{ + struct kobject *kobj = &channel->kobj; + + channel->mmap_ring_buffer = hv_mmap_ring_buffer; + channel->ring_sysfs_visible = true; + + return sysfs_update_group(kobj, &vmbus_chan_group); +} +EXPORT_SYMBOL_GPL(hv_create_ring_sysfs); + +/** + * hv_remove_ring_sysfs() - remove ring sysfs entry corresponding to ring buffers for a channel. + * @channel: Pointer to vmbus_channel structure + * + * Hide "ring" sysfs for a channel by changing its is_visible attribute and updating sysfs group. + * + * Returns 0 on success or error code on failure. + */ +int hv_remove_ring_sysfs(struct vmbus_channel *channel) +{ + struct kobject *kobj = &channel->kobj; + int ret; + + channel->ring_sysfs_visible = false; + ret = sysfs_update_group(kobj, &vmbus_chan_group); + channel->mmap_ring_buffer = NULL; + return ret; +} +EXPORT_SYMBOL_GPL(hv_remove_ring_sysfs); + /* * vmbus_add_channel_kobj - setup a sub-directory under device/channels */ diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c index 1b19b5647495..69c1df0f4ca5 100644 --- a/drivers/uio/uio_hv_generic.c +++ b/drivers/uio/uio_hv_generic.c @@ -131,15 +131,12 @@ static void hv_uio_rescind(struct vmbus_channel *channel) vmbus_device_unregister(channel->device_obj); } -/* Sysfs API to allow mmap of the ring buffers +/* Function used for mmap of ring buffer sysfs interface. * The ring buffer is allocated as contiguous memory by vmbus_open */ -static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj, - const struct bin_attribute *attr, - struct vm_area_struct *vma) +static int +hv_uio_ring_mmap(struct vmbus_channel *channel, struct vm_area_struct *vma) { - struct vmbus_channel *channel - = container_of(kobj, struct vmbus_channel, kobj); void *ring_buffer = page_address(channel->ringbuffer_page); if (channel->state != CHANNEL_OPENED_STATE) @@ -149,15 +146,6 @@ static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj, channel->ringbuffer_pagecount << PAGE_SHIFT); } -static const struct bin_attribute ring_buffer_bin_attr = { - .attr = { - .name = "ring", - .mode = 0600, - }, - .size = 2 * SZ_2M, - .mmap = hv_uio_ring_mmap, -}; - /* Callback from VMBUS subsystem when new channel created. */ static void hv_uio_new_channel(struct vmbus_channel *new_sc) @@ -178,8 +166,7 @@ hv_uio_new_channel(struct vmbus_channel *new_sc) /* Disable interrupts on sub channel */ new_sc->inbound.ring_buffer->interrupt_mask = 1; set_channel_read_mode(new_sc, HV_CALL_ISR); - - ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr); + ret = hv_create_ring_sysfs(new_sc, hv_uio_ring_mmap); if (ret) { dev_err(device, "sysfs create ring bin file failed; %d\n", ret); vmbus_close(new_sc); @@ -350,10 +337,18 @@ hv_uio_probe(struct hv_device *dev, goto fail_close; } - ret = sysfs_create_bin_file(&channel->kobj, &ring_buffer_bin_attr); - if (ret) - dev_notice(&dev->device, - "sysfs create ring bin file failed; %d\n", ret); + /* + * This internally calls sysfs_update_group, which returns a non-zero value if it executes + * before sysfs_create_group. This is expected as the 'ring' will be created later in + * vmbus_device_register() -> vmbus_add_channel_kobj(). Thus, no need to check the return + * value and print warning. + * + * Creating/exposing sysfs in driver probe is not encouraged as it can lead to race + * conditions with userspace. For backward compatibility, "ring" sysfs could not be removed + * or decoupled from uio_hv_generic probe. Userspace programs can make use of inotify + * APIs to make sure that ring is created. + */ + hv_create_ring_sysfs(channel, hv_uio_ring_mmap); hv_set_drvdata(dev, pdata); @@ -375,7 +370,7 @@ hv_uio_remove(struct hv_device *dev) if (!pdata) return; - sysfs_remove_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr); + hv_remove_ring_sysfs(dev->channel); uio_unregister_device(&pdata->info); hv_uio_cleanup(dev, pdata); diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 675959fb97ba..d6ffe01962c2 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1002,6 +1002,12 @@ struct vmbus_channel { /* The max size of a packet on this channel */ u32 max_pkt_size; + + /* function to mmap ring buffer memory to the channel's sysfs ring attribute */ + int (*mmap_ring_buffer)(struct vmbus_channel *channel, struct vm_area_struct *vma); + + /* boolean to control visibility of sysfs for ring buffer */ + bool ring_sysfs_visible; }; #define lock_requestor(channel, flags) \

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[PATCH v2] clk: meson-g12a: fix missing spicc clks to clk_sel

by Da Xue

HHI_SPICC_CLK_CNTL bits 25:23 controls spicc clk_sel. It is missing fclk_div 2 and gp0_pll which causes the spicc module to output the incorrect clocks for spicc sclk at 2.5x the expected rate. Add the missing clocks resolves this. Fixes: a18c8e0b7697 ("clk: meson: g12a: add support for the SPICC SCLK Source clocks") Cc: <stable(a)vger.kernel.org> # 6.1 Signed-off-by: Da Xue <da(a)libre.computer> --- Changelog: v1 -> v2: add Fixes as an older version of the patch was incorrectly sent as v1 --- drivers/clk/meson/g12a.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/clk/meson/g12a.c b/drivers/clk/meson/g12a.c index 4f92b83965d5a..892862bf39996 100644 --- a/drivers/clk/meson/g12a.c +++ b/drivers/clk/meson/g12a.c @@ -4099,8 +4099,10 @@ static const struct clk_parent_data spicc_sclk_parent_data[] = { { .hw = &g12a_clk81.hw }, { .hw = &g12a_fclk_div4.hw }, { .hw = &g12a_fclk_div3.hw }, + { .hw = &g12a_fclk_div2.hw }, { .hw = &g12a_fclk_div5.hw }, { .hw = &g12a_fclk_div7.hw }, + { .hw = &g12a_gp0_pll.hw, }, }; static struct clk_regmap g12a_spicc0_sclk_sel = { -- 2.39.5

4 months, 1 week

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[PATCH v2] drm/tiny: panel-mipi-dbi: Use drm_client_setup_with_fourcc()

by Fabio Estevam

From: Fabio Estevam <festevam(a)denx.de> Since commit 559358282e5b ("drm/fb-helper: Don't use the preferred depth for the BPP default"), RGB565 displays such as the CFAF240320X no longer render correctly: colors are distorted and the content is shown twice horizontally. This regression is due to the fbdev emulation layer defaulting to 32 bits per pixel, whereas the display expects 16 bpp (RGB565). As a result, the framebuffer data is incorrectly interpreted by the panel. Fix the issue by calling drm_client_setup_with_fourcc() with a format explicitly selected based on the display's bits-per-pixel value. For 16 bpp, use DRM_FORMAT_RGB565; for other values, fall back to the previous behavior. This ensures that the allocated framebuffer format matches the hardware expectations, avoiding color and layout corruption. Tested on a CFAF240320X display with an RGB565 configuration, confirming correct colors and layout after applying this patch. Cc: stable(a)vger.kernel.org Fixes: 559358282e5b ("drm/fb-helper: Don't use the preferred depth for the BPP default") Signed-off-by: Fabio Estevam <festevam(a)denx.de> Reviewed-by: Thomas Zimmermann <tzimmermann(a)suse.de> --- Changes since v1: - Improved the commit log. - Added Thomas' Reviewed-by tag. - Added more maintainers on Cc as panel-mipi-dbi.c has been marked as orphan. drivers/gpu/drm/tiny/panel-mipi-dbi.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/tiny/panel-mipi-dbi.c b/drivers/gpu/drm/tiny/panel-mipi-dbi.c index 0460ecaef4bd..23914a9f7fd3 100644 --- a/drivers/gpu/drm/tiny/panel-mipi-dbi.c +++ b/drivers/gpu/drm/tiny/panel-mipi-dbi.c @@ -390,7 +390,10 @@ static int panel_mipi_dbi_spi_probe(struct spi_device *spi) spi_set_drvdata(spi, drm); - drm_client_setup(drm, NULL); + if (bpp == 16) + drm_client_setup_with_fourcc(drm, DRM_FORMAT_RGB565); + else + drm_client_setup_with_fourcc(drm, DRM_FORMAT_RGB888); return 0; } -- 2.34.1

4 months, 1 week

3
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[PATCH] wifi: mt76: disable napi on driver removal

by Fedor Pchelkin

A warning on driver removal started occurring after commit 9dd05df8403b ("net: warn if NAPI instance wasn't shut down"). Disable tx napi before deleting it in mt76_dma_cleanup(). WARNING: CPU: 4 PID: 18828 at net/core/dev.c:7288 __netif_napi_del_locked+0xf0/0x100 CPU: 4 UID: 0 PID: 18828 Comm: modprobe Not tainted 6.15.0-rc4 #4 PREEMPT(lazy) Hardware name: ASUS System Product Name/PRIME X670E-PRO WIFI, BIOS 3035 09/05/2024 RIP: 0010:__netif_napi_del_locked+0xf0/0x100 Call Trace: <TASK> mt76_dma_cleanup+0x54/0x2f0 [mt76] mt7921_pci_remove+0xd5/0x190 [mt7921e] pci_device_remove+0x47/0xc0 device_release_driver_internal+0x19e/0x200 driver_detach+0x48/0x90 bus_remove_driver+0x6d/0xf0 pci_unregister_driver+0x2e/0xb0 __do_sys_delete_module.isra.0+0x197/0x2e0 do_syscall_64+0x7b/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e Tested with mt7921e but the same pattern can be actually applied to other mt76 drivers calling mt76_dma_cleanup() during removal. Tx napi is enabled in their *_dma_init() functions and only toggled off and on again inside their suspend/resume/reset paths. So it should be okay to disable tx napi in such a generic way. Found by Linux Verification Center (linuxtesting.org). Fixes: 2ac515a5d74f ("mt76: mt76x02: use napi polling for tx cleanup") Cc: stable(a)vger.kernel.org Signed-off-by: Fedor Pchelkin <pchelkin(a)ispras.ru> --- drivers/net/wireless/mediatek/mt76/dma.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c index 844af16ee551..35b4ec91979e 100644 --- a/drivers/net/wireless/mediatek/mt76/dma.c +++ b/drivers/net/wireless/mediatek/mt76/dma.c @@ -1011,6 +1011,7 @@ void mt76_dma_cleanup(struct mt76_dev *dev) int i; mt76_worker_disable(&dev->tx_worker); + napi_disable(&dev->tx_napi); netif_napi_del(&dev->tx_napi); for (i = 0; i < ARRAY_SIZE(dev->phys); i++) { -- 2.49.0

4 months, 1 week

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[PATCH 6.1.y 2/2] drm/msm/dpu: move dpu_encoder's connector assignment to atomic_enable()

by jianqi.ren.cn＠windriver.com

From: Abhinav Kumar <quic_abhinavk(a)quicinc.com> [ Upstream commit aedf02e46eb549dac8db4821a6b9f0c6bf6e3990 ] For cases where the crtc's connectors_changed was set without enable/active getting toggled , there is an atomic_enable() call followed by an atomic_disable() but without an atomic_mode_set(). This results in a NULL ptr access for the dpu_encoder_get_drm_fmt() call in the atomic_enable() as the dpu_encoder's connector was cleared in the atomic_disable() but not re-assigned as there was no atomic_mode_set() call. Fix the NULL ptr access by moving the assignment for atomic_enable() and also use drm_atomic_get_new_connector_for_encoder() to get the connector from the atomic_state. Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support") Reported-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/59 Suggested-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> Tested-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> # SM8350-HDK Patchwork: https://patchwork.freedesktop.org/patch/606729/ Link: https://lore.kernel.org/r/20240731191723.3050932-1-quic_abhinavk@quicinc.com Signed-off-by: Abhinav Kumar <quic_abhinavk(a)quicinc.com> [Minor conflict resolved due to code context change.] Signed-off-by: Jianqi Ren <jianqi.ren.cn(a)windriver.com> Signed-off-by: He Zhe <zhe.he(a)windriver.com> --- Verified the build test --- drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c index c7fcd617b48c..94f352253c74 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c @@ -1101,8 +1101,6 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc, cstate->num_mixers = num_lm; - dpu_enc->connector = conn_state->connector; - for (i = 0; i < dpu_enc->num_phys_encs; i++) { struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i]; @@ -1192,6 +1190,9 @@ static void dpu_encoder_virt_atomic_enable(struct drm_encoder *drm_enc, dpu_enc = to_dpu_encoder_virt(drm_enc); mutex_lock(&dpu_enc->enc_lock); + + dpu_enc->connector = drm_atomic_get_new_connector_for_encoder(state, drm_enc); + cur_mode = &dpu_enc->base.crtc->state->adjusted_mode; trace_dpu_enc_enable(DRMID(drm_enc), cur_mode->hdisplay, -- 2.34.1

4 months, 1 week

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[PATCH] usb: cdnsp: Fix issue with detecting command completion event

by Pawel Laszczak

In some cases, there is a small-time gap in which CMD_RING_BUSY can be cleared by controller but adding command completion event to event ring will be delayed. As the result driver will return error code. This behavior has been detected on usbtest driver (test 9) with configuration including ep1in/ep1out bulk and ep2in/ep2out isoc endpoint. Probably this gap occurred because controller was busy with adding some other events to event ring. The CMD_RING_BUSY is cleared to '0' when the Command Descriptor has been executed and not when command completion event has been added to event ring. To fix this issue for this test the small delay is sufficient less than 10us) but to make sure the problem doesn't happen again in the future the patch introduce 3 retries to check with delay about 100us before returning error code Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver") cc: stable(a)vger.kernel.org Signed-off-by: Pawel Laszczak <pawell(a)cadence.com> --- drivers/usb/cdns3/cdnsp-gadget.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/usb/cdns3/cdnsp-gadget.c b/drivers/usb/cdns3/cdnsp-gadget.c index f773518185c9..0eb11b5dd9d3 100644 --- a/drivers/usb/cdns3/cdnsp-gadget.c +++ b/drivers/usb/cdns3/cdnsp-gadget.c @@ -547,6 +547,7 @@ int cdnsp_wait_for_cmd_compl(struct cdnsp_device *pdev) dma_addr_t cmd_deq_dma; union cdnsp_trb *event; u32 cycle_state; + u32 retry = 3; int ret, val; u64 cmd_dma; u32 flags; @@ -578,8 +579,23 @@ int cdnsp_wait_for_cmd_compl(struct cdnsp_device *pdev) flags = le32_to_cpu(event->event_cmd.flags); /* Check the owner of the TRB. */ - if ((flags & TRB_CYCLE) != cycle_state) + if ((flags & TRB_CYCLE) != cycle_state) { + /* + *Give some extra time to get chance controller + * to finish command before returning error code. + * Checking CMD_RING_BUSY is not sufficient because + * this bit is cleared to '0' when the Command + * Descriptor has been executed by controller + * and not when command completion event has + * be added to event ring. + */ + if (retry--) { + usleep_range(90, 100); + continue; + } + return -EINVAL; + } cmd_dma = le64_to_cpu(event->event_cmd.cmd_trb); -- 2.43.0

4 months, 1 week

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[merged mm-nonmm-stable] ipc-fix-to-protect-ipcs-lookups-using-rcu.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: ipc: fix to protect IPCS lookups using RCU has been removed from the -mm tree. Its filename was ipc-fix-to-protect-ipcs-lookups-using-rcu.patch This patch was dropped because it was merged into the mm-nonmm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Jeongjun Park <aha310510(a)gmail.com> Subject: ipc: fix to protect IPCS lookups using RCU Date: Thu, 24 Apr 2025 23:33:22 +0900 syzbot reported that it discovered a use-after-free vulnerability, [0] [0]: https://lore.kernel.org/all/67af13f8.050a0220.21dd3.0038.GAE@google.com/ idr_for_each() is protected by rwsem, but this is not enough. If it is not protected by RCU read-critical region, when idr_for_each() calls radix_tree_node_free() through call_rcu() to free the radix_tree_node structure, the node will be freed immediately, and when reading the next node in radix_tree_for_each_slot(), the already freed memory may be read. Therefore, we need to add code to make sure that idr_for_each() is protected within the RCU read-critical region when we call it in shm_destroy_orphaned(). Link: https://lkml.kernel.org/r/20250424143322.18830-1-aha310510@gmail.com Fixes: b34a6b1da371 ("ipc: introduce shm_rmid_forced sysctl") Signed-off-by: Jeongjun Park <aha310510(a)gmail.com> Reported-by: syzbot+a2b84e569d06ca3a949c(a)syzkaller.appspotmail.com Cc: Jeongjun Park <aha310510(a)gmail.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org> Cc: Vasiliy Kulikov <segoon(a)openwall.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- ipc/shm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/ipc/shm.c~ipc-fix-to-protect-ipcs-lookups-using-rcu +++ a/ipc/shm.c @@ -431,8 +431,11 @@ static int shm_try_destroy_orphaned(int void shm_destroy_orphaned(struct ipc_namespace *ns) { down_write(&shm_ids(ns).rwsem); - if (shm_ids(ns).in_use) + if (shm_ids(ns).in_use) { + rcu_read_lock(); idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns); + rcu_read_unlock(); + } up_write(&shm_ids(ns).rwsem); } _ Patches currently in -mm which might be from aha310510(a)gmail.com are mm-vmalloc-fix-data-race-in-show_numa_info.patch

4 months, 1 week

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[merged mm-nonmm-stable] watchdog-fix-watchdog-may-detect-false-positive-of-softlockup.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: watchdog: fix watchdog may detect false positive of softlockup has been removed from the -mm tree. Its filename was watchdog-fix-watchdog-may-detect-false-positive-of-softlockup.patch This patch was dropped because it was merged into the mm-nonmm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Luo Gengkun <luogengkun(a)huaweicloud.com> Subject: watchdog: fix watchdog may detect false positive of softlockup Date: Mon, 21 Apr 2025 03:50:21 +0000 When updating `watchdog_thresh`, there is a race condition between writing the new `watchdog_thresh` value and stopping the old watchdog timer. If the old timer triggers during this window, it may falsely detect a softlockup due to the old interval and the new `watchdog_thresh` value being used. The problem can be described as follow: # We asuume previous watchdog_thresh is 60, so the watchdog timer is # coming every 24s. echo 10 > /proc/sys/kernel/watchdog_thresh (User space) | +------>+ update watchdog_thresh (We are in kernel now) | | # using old interval and new `watchdog_thresh` +------>+ watchdog hrtimer (irq context: detect softlockup) | | +-------+ | | + softlockup_stop_all To fix this problem, introduce a shadow variable for `watchdog_thresh`. The update to the actual `watchdog_thresh` is delayed until after the old timer is stopped, preventing false positives. The following testcase may help to understand this problem. --------------------------------------------- echo RT_RUNTIME_SHARE > /sys/kernel/debug/sched/features echo -1 > /proc/sys/kernel/sched_rt_runtime_us echo 0 > /sys/kernel/debug/sched/fair_server/cpu3/runtime echo 60 > /proc/sys/kernel/watchdog_thresh taskset -c 3 chrt -r 99 /bin/bash -c "while true;do true; done" & echo 10 > /proc/sys/kernel/watchdog_thresh & --------------------------------------------- The test case above first removes the throttling restrictions for real-time tasks. It then sets watchdog_thresh to 60 and executes a real-time task ,a simple while(1) loop, on cpu3. Consequently, the final command gets blocked because the presence of this real-time thread prevents kworker:3 from being selected by the scheduler. This eventually triggers a softlockup detection on cpu3 due to watchdog_timer_fn operating with inconsistent variable - using both the old interval and the updated watchdog_thresh simultaneously. [nysal(a)linux.ibm.com: fix the SOFTLOCKUP_DETECTOR=n case] Link: https://lkml.kernel.org/r/20250502111120.282690-1-nysal@linux.ibm.com Link: https://lkml.kernel.org/r/20250421035021.3507649-1-luogengkun@huaweicloud.c… Signed-off-by: Luo Gengkun <luogengkun(a)huaweicloud.com> Signed-off-by: Nysal Jan K.A. <nysal(a)linux.ibm.com> Cc: Doug Anderson <dianders(a)chromium.org> Cc: Joel Granados <joel.granados(a)kernel.org> Cc: Song Liu <song(a)kernel.org> Cc: Thomas Gleinxer <tglx(a)linutronix.de> Cc: "Nysal Jan K.A." <nysal(a)linux.ibm.com> Cc: Venkat Rao Bagalkote <venkat88(a)linux.ibm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- kernel/watchdog.c | 41 +++++++++++++++++++++++++++-------------- 1 file changed, 27 insertions(+), 14 deletions(-) --- a/kernel/watchdog.c~watchdog-fix-watchdog-may-detect-false-positive-of-softlockup +++ a/kernel/watchdog.c @@ -47,6 +47,7 @@ int __read_mostly watchdog_user_enabled static int __read_mostly watchdog_hardlockup_user_enabled = WATCHDOG_HARDLOCKUP_DEFAULT; static int __read_mostly watchdog_softlockup_user_enabled = 1; int __read_mostly watchdog_thresh = 10; +static int __read_mostly watchdog_thresh_next; static int __read_mostly watchdog_hardlockup_available; struct cpumask watchdog_cpumask __read_mostly; @@ -870,12 +871,20 @@ int lockup_detector_offline_cpu(unsigned return 0; } -static void __lockup_detector_reconfigure(void) +static void __lockup_detector_reconfigure(bool thresh_changed) { cpus_read_lock(); watchdog_hardlockup_stop(); softlockup_stop_all(); + /* + * To prevent watchdog_timer_fn from using the old interval and + * the new watchdog_thresh at the same time, which could lead to + * false softlockup reports, it is necessary to update the + * watchdog_thresh after the softlockup is completed. + */ + if (thresh_changed) + watchdog_thresh = READ_ONCE(watchdog_thresh_next); set_sample_period(); lockup_detector_update_enable(); if (watchdog_enabled && watchdog_thresh) @@ -888,7 +897,7 @@ static void __lockup_detector_reconfigur void lockup_detector_reconfigure(void) { mutex_lock(&watchdog_mutex); - __lockup_detector_reconfigure(); + __lockup_detector_reconfigure(false); mutex_unlock(&watchdog_mutex); } @@ -908,27 +917,29 @@ static __init void lockup_detector_setup return; mutex_lock(&watchdog_mutex); - __lockup_detector_reconfigure(); + __lockup_detector_reconfigure(false); softlockup_initialized = true; mutex_unlock(&watchdog_mutex); } #else /* CONFIG_SOFTLOCKUP_DETECTOR */ -static void __lockup_detector_reconfigure(void) +static void __lockup_detector_reconfigure(bool thresh_changed) { cpus_read_lock(); watchdog_hardlockup_stop(); + if (thresh_changed) + watchdog_thresh = READ_ONCE(watchdog_thresh_next); lockup_detector_update_enable(); watchdog_hardlockup_start(); cpus_read_unlock(); } void lockup_detector_reconfigure(void) { - __lockup_detector_reconfigure(); + __lockup_detector_reconfigure(false); } static inline void lockup_detector_setup(void) { - __lockup_detector_reconfigure(); + __lockup_detector_reconfigure(false); } #endif /* !CONFIG_SOFTLOCKUP_DETECTOR */ @@ -946,11 +957,11 @@ void lockup_detector_soft_poweroff(void) #ifdef CONFIG_SYSCTL /* Propagate any changes to the watchdog infrastructure */ -static void proc_watchdog_update(void) +static void proc_watchdog_update(bool thresh_changed) { /* Remove impossible cpus to keep sysctl output clean. */ cpumask_and(&watchdog_cpumask, &watchdog_cpumask, cpu_possible_mask); - __lockup_detector_reconfigure(); + __lockup_detector_reconfigure(thresh_changed); } /* @@ -984,7 +995,7 @@ static int proc_watchdog_common(int whic } else { err = proc_dointvec_minmax(table, write, buffer, lenp, ppos); if (!err && old != READ_ONCE(*param)) - proc_watchdog_update(); + proc_watchdog_update(false); } mutex_unlock(&watchdog_mutex); return err; @@ -1035,11 +1046,13 @@ static int proc_watchdog_thresh(const st mutex_lock(&watchdog_mutex); - old = READ_ONCE(watchdog_thresh); + watchdog_thresh_next = READ_ONCE(watchdog_thresh); + + old = watchdog_thresh_next; err = proc_dointvec_minmax(table, write, buffer, lenp, ppos); - if (!err && write && old != READ_ONCE(watchdog_thresh)) - proc_watchdog_update(); + if (!err && write && old != READ_ONCE(watchdog_thresh_next)) + proc_watchdog_update(true); mutex_unlock(&watchdog_mutex); return err; @@ -1060,7 +1073,7 @@ static int proc_watchdog_cpumask(const s err = proc_do_large_bitmap(table, write, buffer, lenp, ppos); if (!err && write) - proc_watchdog_update(); + proc_watchdog_update(false); mutex_unlock(&watchdog_mutex); return err; @@ -1080,7 +1093,7 @@ static const struct ctl_table watchdog_s }, { .procname = "watchdog_thresh", - .data = &watchdog_thresh, + .data = &watchdog_thresh_next, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_watchdog_thresh, _ Patches currently in -mm which might be from luogengkun(a)huaweicloud.com are

4 months, 1 week

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[merged mm-stable] mm-fix-ratelimit_pages-update-error-in-dirty_ratio_handler.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm: fix ratelimit_pages update error in dirty_ratio_handler() has been removed from the -mm tree. Its filename was mm-fix-ratelimit_pages-update-error-in-dirty_ratio_handler.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Jinliang Zheng <alexjlzheng(a)tencent.com> Subject: mm: fix ratelimit_pages update error in dirty_ratio_handler() Date: Tue, 15 Apr 2025 17:02:32 +0800 In dirty_ratio_handler(), vm_dirty_bytes must be set to zero before calling writeback_set_ratelimit(), as global_dirty_limits() always prioritizes the value of vm_dirty_bytes. It's domain_dirty_limits() that's relevant here, not node_dirty_ok: dirty_ratio_handler writeback_set_ratelimit global_dirty_limits(&dirty_thresh) <- ratelimit_pages based on dirty_thresh domain_dirty_limits if (bytes) <- bytes = vm_dirty_bytes <--------+ thresh = f1(bytes) <- prioritizes vm_dirty_bytes | else | thresh = f2(ratio) | ratelimit_pages = f3(dirty_thresh) | vm_dirty_bytes = 0 <- it's late! ---------------------+ This causes ratelimit_pages to still use the value calculated based on vm_dirty_bytes, which is wrong now. The impact visible to userspace is difficult to capture directly because there is no procfs/sysfs interface exported to user space. However, it will have a real impact on the balance of dirty pages. For example: 1. On default, we have vm_dirty_ratio=40, vm_dirty_bytes=0 2. echo 8192 > dirty_bytes, then vm_dirty_bytes=8192, vm_dirty_ratio=0, and ratelimit_pages is calculated based on vm_dirty_bytes now. 3. echo 20 > dirty_ratio, then since vm_dirty_bytes is not reset to zero when writeback_set_ratelimit() -> global_dirty_limits() -> domain_dirty_limits() is called, reallimit_pages is still calculated based on vm_dirty_bytes instead of vm_dirty_ratio. This does not conform to the actual intent of the user. Link: https://lkml.kernel.org/r/20250415090232.7544-1-alexjlzheng@tencent.com Fixes: 9d823e8f6b1b ("writeback: per task dirty rate limit") Signed-off-by: Jinliang Zheng <alexjlzheng(a)tencent.com> Reviewed-by: MengEn Sun <mengensun(a)tencent.com> Cc: Andrea Righi <andrea(a)betterlinux.com> Cc: Fenggaung Wu <fengguang.wu(a)intel.com> Cc: Jinliang Zheng <alexjlzheng(a)tencent.com> Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/page-writeback.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/page-writeback.c~mm-fix-ratelimit_pages-update-error-in-dirty_ratio_handler +++ a/mm/page-writeback.c @@ -520,8 +520,8 @@ static int dirty_ratio_handler(const str ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); if (ret == 0 && write && vm_dirty_ratio != old_ratio) { - writeback_set_ratelimit(); vm_dirty_bytes = 0; + writeback_set_ratelimit(); } return ret; } _ Patches currently in -mm which might be from alexjlzheng(a)tencent.com are

4 months, 1 week

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[merged mm-hotfixes-stable] mm-userfaultfd-correct-dirty-flags-set-for-both-present-and-swap-pte.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm: userfaultfd: correct dirty flags set for both present and swap pte has been removed from the -mm tree. Its filename was mm-userfaultfd-correct-dirty-flags-set-for-both-present-and-swap-pte.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Barry Song <v-songbaohua(a)oppo.com> Subject: mm: userfaultfd: correct dirty flags set for both present and swap pte Date: Fri, 9 May 2025 10:09:12 +1200 As David pointed out, what truly matters for mremap and userfaultfd move operations is the soft dirty bit. The current comment and implementation��which always sets the dirty bit for present PTEs and fails to set the soft dirty bit for swap PTEs��are incorrect. This could break features like Checkpoint-Restore in Userspace (CRIU). This patch updates the behavior to correctly set the soft dirty bit for both present and swap PTEs in accordance with mremap. Link: https://lkml.kernel.org/r/20250508220912.7275-1-21cnbao@gmail.com Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Barry Song <v-songbaohua(a)oppo.com> Reported-by: David Hildenbrand <david(a)redhat.com> Closes: https://lore.kernel.org/linux-mm/02f14ee1-923f-47e3-a994-4950afb9afcc@redha… Acked-by: Peter Xu <peterx(a)redhat.com> Reviewed-by: Suren Baghdasaryan <surenb(a)google.com> Cc: Lokesh Gidra <lokeshgidra(a)google.com> Cc: Andrea Arcangeli <aarcange(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/userfaultfd.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/mm/userfaultfd.c~mm-userfaultfd-correct-dirty-flags-set-for-both-present-and-swap-pte +++ a/mm/userfaultfd.c @@ -1064,8 +1064,13 @@ static int move_present_pte(struct mm_st src_folio->index = linear_page_index(dst_vma, dst_addr); orig_dst_pte = mk_pte(&src_folio->page, dst_vma->vm_page_prot); - /* Follow mremap() behavior and treat the entry dirty after the move */ - orig_dst_pte = pte_mkwrite(pte_mkdirty(orig_dst_pte), dst_vma); + /* Set soft dirty bit so userspace can notice the pte was moved */ +#ifdef CONFIG_MEM_SOFT_DIRTY + orig_dst_pte = pte_mksoft_dirty(orig_dst_pte); +#endif + if (pte_dirty(orig_src_pte)) + orig_dst_pte = pte_mkdirty(orig_dst_pte); + orig_dst_pte = pte_mkwrite(orig_dst_pte, dst_vma); set_pte_at(mm, dst_addr, dst_pte, orig_dst_pte); out: @@ -1100,6 +1105,9 @@ static int move_swap_pte(struct mm_struc } orig_src_pte = ptep_get_and_clear(mm, src_addr, src_pte); +#ifdef CONFIG_MEM_SOFT_DIRTY + orig_src_pte = pte_swp_mksoft_dirty(orig_src_pte); +#endif set_pte_at(mm, dst_addr, dst_pte, orig_src_pte); double_pt_unlock(dst_ptl, src_ptl); _ Patches currently in -mm which might be from v-songbaohua(a)oppo.com are

4 months, 1 week

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[merged mm-hotfixes-stable] mm-page_alloc-fix-race-condition-in-unaccepted-memory-handling.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/page_alloc: fix race condition in unaccepted memory handling has been removed from the -mm tree. Its filename was mm-page_alloc-fix-race-condition-in-unaccepted-memory-handling.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: "Kirill A. Shutemov" <kirill.shutemov(a)linux.intel.com> Subject: mm/page_alloc: fix race condition in unaccepted memory handling Date: Tue, 6 May 2025 16:32:07 +0300 The page allocator tracks the number of zones that have unaccepted memory using static_branch_enc/dec() and uses that static branch in hot paths to determine if it needs to deal with unaccepted memory. Borislav and Thomas pointed out that the tracking is racy: operations on static_branch are not serialized against adding/removing unaccepted pages to/from the zone. Sanity checks inside static_branch machinery detects it: WARNING: CPU: 0 PID: 10 at kernel/jump_label.c:276 __static_key_slow_dec_cpuslocked+0x8e/0xa0 The comment around the WARN() explains the problem: /* * Warn about the '-1' case though; since that means a * decrement is concurrent with a first (0->1) increment. IOW * people are trying to disable something that wasn't yet fully * enabled. This suggests an ordering problem on the user side. */ The effect of this static_branch optimization is only visible on microbenchmark. Instead of adding more complexity around it, remove it altogether. Link: https://lkml.kernel.org/r/20250506133207.1009676-1-kirill.shutemov@linux.in… Signed-off-by: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com> Fixes: dcdfdd40fa82 ("mm: Add support for unaccepted memory") Link: https://lore.kernel.org/all/20250506092445.GBaBnVXXyvnazly6iF@fat_crate.loc… Reported-by: Borislav Petkov <bp(a)alien8.de> Tested-by: Borislav Petkov (AMD) <bp(a)alien8.de> Reported-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: Michal Hocko <mhocko(a)suse.com> Cc: Brendan Jackman <jackmanb(a)google.com> Cc: Johannes Weiner <hannes(a)cmpxchg.org> Cc: <stable(a)vger.kernel.org> [6.5+] Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/internal.h | 1 mm/mm_init.c | 1 mm/page_alloc.c | 47 ---------------------------------------------- 3 files changed, 49 deletions(-) --- a/mm/internal.h~mm-page_alloc-fix-race-condition-in-unaccepted-memory-handling +++ a/mm/internal.h @@ -1590,7 +1590,6 @@ unsigned long move_page_tables(struct pa #ifdef CONFIG_UNACCEPTED_MEMORY void accept_page(struct page *page); -void unaccepted_cleanup_work(struct work_struct *work); #else /* CONFIG_UNACCEPTED_MEMORY */ static inline void accept_page(struct page *page) { --- a/mm/mm_init.c~mm-page_alloc-fix-race-condition-in-unaccepted-memory-handling +++ a/mm/mm_init.c @@ -1441,7 +1441,6 @@ static void __meminit zone_init_free_lis #ifdef CONFIG_UNACCEPTED_MEMORY INIT_LIST_HEAD(&zone->unaccepted_pages); - INIT_WORK(&zone->unaccepted_cleanup, unaccepted_cleanup_work); #endif } --- a/mm/page_alloc.c~mm-page_alloc-fix-race-condition-in-unaccepted-memory-handling +++ a/mm/page_alloc.c @@ -7172,16 +7172,8 @@ bool has_managed_dma(void) #ifdef CONFIG_UNACCEPTED_MEMORY -/* Counts number of zones with unaccepted pages. */ -static DEFINE_STATIC_KEY_FALSE(zones_with_unaccepted_pages); - static bool lazy_accept = true; -void unaccepted_cleanup_work(struct work_struct *work) -{ - static_branch_dec(&zones_with_unaccepted_pages); -} - static int __init accept_memory_parse(char *p) { if (!strcmp(p, "lazy")) { @@ -7206,11 +7198,7 @@ static bool page_contains_unaccepted(str static void __accept_page(struct zone *zone, unsigned long *flags, struct page *page) { - bool last; - list_del(&page->lru); - last = list_empty(&zone->unaccepted_pages); - account_freepages(zone, -MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE); __mod_zone_page_state(zone, NR_UNACCEPTED, -MAX_ORDER_NR_PAGES); __ClearPageUnaccepted(page); @@ -7219,28 +7207,6 @@ static void __accept_page(struct zone *z accept_memory(page_to_phys(page), PAGE_SIZE << MAX_PAGE_ORDER); __free_pages_ok(page, MAX_PAGE_ORDER, FPI_TO_TAIL); - - if (last) { - /* - * There are two corner cases: - * - * - If allocation occurs during the CPU bring up, - * static_branch_dec() cannot be used directly as - * it causes a deadlock on cpu_hotplug_lock. - * - * Instead, use schedule_work() to prevent deadlock. - * - * - If allocation occurs before workqueues are initialized, - * static_branch_dec() should be called directly. - * - * Workqueues are initialized before CPU bring up, so this - * will not conflict with the first scenario. - */ - if (system_wq) - schedule_work(&zone->unaccepted_cleanup); - else - unaccepted_cleanup_work(&zone->unaccepted_cleanup); - } } void accept_page(struct page *page) @@ -7277,20 +7243,12 @@ static bool try_to_accept_memory_one(str return true; } -static inline bool has_unaccepted_memory(void) -{ - return static_branch_unlikely(&zones_with_unaccepted_pages); -} - static bool cond_accept_memory(struct zone *zone, unsigned int order, int alloc_flags) { long to_accept, wmark; bool ret = false; - if (!has_unaccepted_memory()) - return false; - if (list_empty(&zone->unaccepted_pages)) return false; @@ -7328,22 +7286,17 @@ static bool __free_unaccepted(struct pag { struct zone *zone = page_zone(page); unsigned long flags; - bool first = false; if (!lazy_accept) return false; spin_lock_irqsave(&zone->lock, flags); - first = list_empty(&zone->unaccepted_pages); list_add_tail(&page->lru, &zone->unaccepted_pages); account_freepages(zone, MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE); __mod_zone_page_state(zone, NR_UNACCEPTED, MAX_ORDER_NR_PAGES); __SetPageUnaccepted(page); spin_unlock_irqrestore(&zone->lock, flags); - if (first) - static_branch_inc(&zones_with_unaccepted_pages); - return true; } _ Patches currently in -mm which might be from kirill.shutemov(a)linux.intel.com are

4 months, 1 week

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[merged mm-hotfixes-stable] mm-page_alloc-ensure-try_alloc_pages-plays-well-with-unaccepted-memory.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/page_alloc: ensure try_alloc_pages() plays well with unaccepted memory has been removed from the -mm tree. Its filename was mm-page_alloc-ensure-try_alloc_pages-plays-well-with-unaccepted-memory.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: "Kirill A. Shutemov" <kirill.shutemov(a)linux.intel.com> Subject: mm/page_alloc: ensure try_alloc_pages() plays well with unaccepted memory Date: Tue, 6 May 2025 14:25:08 +0300 try_alloc_pages() will not attempt to allocate memory if the system has *any* unaccepted memory. Memory is accepted as needed and can remain in the system indefinitely, causing the interface to always fail. Rather than immediately giving up, attempt to use already accepted memory on free lists. Pass 'alloc_flags' to cond_accept_memory() and do not accept new memory for ALLOC_TRYLOCK requests. Found via code inspection - only BPF uses this at present and the runtime effects are unclear. Link: https://lkml.kernel.org/r/20250506112509.905147-2-kirill.shutemov@linux.int… Signed-off-by: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com> Fixes: 97769a53f117 ("mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation") Cc: Alexei Starovoitov <ast(a)kernel.org> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: Michal Hocko <mhocko(a)suse.com> Cc: Brendan Jackman <jackmanb(a)google.com> Cc: Johannes Weiner <hannes(a)cmpxchg.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/page_alloc.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) --- a/mm/page_alloc.c~mm-page_alloc-ensure-try_alloc_pages-plays-well-with-unaccepted-memory +++ a/mm/page_alloc.c @@ -290,7 +290,8 @@ EXPORT_SYMBOL(nr_online_nodes); #endif static bool page_contains_unaccepted(struct page *page, unsigned int order); -static bool cond_accept_memory(struct zone *zone, unsigned int order); +static bool cond_accept_memory(struct zone *zone, unsigned int order, + int alloc_flags); static bool __free_unaccepted(struct page *page); int page_group_by_mobility_disabled __read_mostly; @@ -3611,7 +3612,7 @@ retry: } } - cond_accept_memory(zone, order); + cond_accept_memory(zone, order, alloc_flags); /* * Detect whether the number of free pages is below high @@ -3638,7 +3639,7 @@ check_alloc_wmark: gfp_mask)) { int ret; - if (cond_accept_memory(zone, order)) + if (cond_accept_memory(zone, order, alloc_flags)) goto try_this_zone; /* @@ -3691,7 +3692,7 @@ try_this_zone: return page; } else { - if (cond_accept_memory(zone, order)) + if (cond_accept_memory(zone, order, alloc_flags)) goto try_this_zone; /* Try again if zone has deferred pages */ @@ -4844,7 +4845,7 @@ unsigned long alloc_pages_bulk_noprof(gf goto failed; } - cond_accept_memory(zone, 0); + cond_accept_memory(zone, 0, alloc_flags); retry_this_zone: mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK) + nr_pages; if (zone_watermark_fast(zone, 0, mark, @@ -4853,7 +4854,7 @@ retry_this_zone: break; } - if (cond_accept_memory(zone, 0)) + if (cond_accept_memory(zone, 0, alloc_flags)) goto retry_this_zone; /* Try again if zone has deferred pages */ @@ -7281,7 +7282,8 @@ static inline bool has_unaccepted_memory return static_branch_unlikely(&zones_with_unaccepted_pages); } -static bool cond_accept_memory(struct zone *zone, unsigned int order) +static bool cond_accept_memory(struct zone *zone, unsigned int order, + int alloc_flags) { long to_accept, wmark; bool ret = false; @@ -7292,6 +7294,10 @@ static bool cond_accept_memory(struct zo if (list_empty(&zone->unaccepted_pages)) return false; + /* Bailout, since try_to_accept_memory_one() needs to take a lock */ + if (alloc_flags & ALLOC_TRYLOCK) + return false; + wmark = promo_wmark_pages(zone); /* @@ -7348,7 +7354,8 @@ static bool page_contains_unaccepted(str return false; } -static bool cond_accept_memory(struct zone *zone, unsigned int order) +static bool cond_accept_memory(struct zone *zone, unsigned int order, + int alloc_flags) { return false; } @@ -7419,11 +7426,6 @@ struct page *try_alloc_pages_noprof(int if (!pcp_allowed_order(order)) return NULL; -#ifdef CONFIG_UNACCEPTED_MEMORY - /* Bailout, since try_to_accept_memory_one() needs to take a lock */ - if (has_unaccepted_memory()) - return NULL; -#endif /* Bailout, since _deferred_grow_zone() needs to take a lock */ if (deferred_pages_enabled()) return NULL; _ Patches currently in -mm which might be from kirill.shutemov(a)linux.intel.com are

4 months, 1 week

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[merged mm-hotfixes-stable] mm-hugetlb-fix-incorrect-fallback-for-subpool.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm: hugetlb: fix incorrect fallback for subpool has been removed from the -mm tree. Its filename was mm-hugetlb-fix-incorrect-fallback-for-subpool.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Wupeng Ma <mawupeng1(a)huawei.com> Subject: mm: hugetlb: fix incorrect fallback for subpool Date: Thu, 10 Apr 2025 14:26:33 +0800 During our testing with hugetlb subpool enabled, we observe that hstate->resv_huge_pages may underflow into negative values. Root cause analysis reveals a race condition in subpool reservation fallback handling as follow: hugetlb_reserve_pages() /* Attempt subpool reservation */ gbl_reserve = hugepage_subpool_get_pages(spool, chg); /* Global reservation may fail after subpool allocation */ if (hugetlb_acct_memory(h, gbl_reserve) < 0) goto out_put_pages; out_put_pages: /* This incorrectly restores reservation to subpool */ hugepage_subpool_put_pages(spool, chg); When hugetlb_acct_memory() fails after subpool allocation, the current implementation over-commits subpool reservations by returning the full 'chg' value instead of the actual allocated 'gbl_reserve' amount. This discrepancy propagates to global reservations during subsequent releases, eventually causing resv_huge_pages underflow. This problem can be trigger easily with the following steps: 1. reverse hugepage for hugeltb allocation 2. mount hugetlbfs with min_size to enable hugetlb subpool 3. alloc hugepages with two task(make sure the second will fail due to insufficient amount of hugepages) 4. with for a few seconds and repeat step 3 which will make hstate->resv_huge_pages to go below zero. To fix this problem, return corrent amount of pages to subpool during the fallback after hugepage_subpool_get_pages is called. Link: https://lkml.kernel.org/r/20250410062633.3102457-1-mawupeng1@huawei.com Fixes: 1c5ecae3a93f ("hugetlbfs: add minimum size accounting to subpools") Signed-off-by: Wupeng Ma <mawupeng1(a)huawei.com> Tested-by: Joshua Hahn <joshua.hahnjy(a)gmail.com> Reviewed-by: Oscar Salvador <osalvador(a)suse.de> Cc: David Hildenbrand <david(a)redhat.com> Cc: Ma Wupeng <mawupeng1(a)huawei.com> Cc: Muchun Song <muchun.song(a)linux.dev> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/hugetlb.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) --- a/mm/hugetlb.c~mm-hugetlb-fix-incorrect-fallback-for-subpool +++ a/mm/hugetlb.c @@ -3010,7 +3010,7 @@ struct folio *alloc_hugetlb_folio(struct struct hugepage_subpool *spool = subpool_vma(vma); struct hstate *h = hstate_vma(vma); struct folio *folio; - long retval, gbl_chg; + long retval, gbl_chg, gbl_reserve; map_chg_state map_chg; int ret, idx; struct hugetlb_cgroup *h_cg = NULL; @@ -3163,8 +3163,16 @@ out_uncharge_cgroup_reservation: hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h), h_cg); out_subpool_put: - if (map_chg) - hugepage_subpool_put_pages(spool, 1); + /* + * put page to subpool iff the quota of subpool's rsv_hpages is used + * during hugepage_subpool_get_pages. + */ + if (map_chg && !gbl_chg) { + gbl_reserve = hugepage_subpool_put_pages(spool, 1); + hugetlb_acct_memory(h, -gbl_reserve); + } + + out_end_reservation: if (map_chg != MAP_CHG_ENFORCED) vma_end_reservation(h, vma, addr); @@ -7239,7 +7247,7 @@ bool hugetlb_reserve_pages(struct inode struct vm_area_struct *vma, vm_flags_t vm_flags) { - long chg = -1, add = -1; + long chg = -1, add = -1, spool_resv, gbl_resv; struct hstate *h = hstate_inode(inode); struct hugepage_subpool *spool = subpool_inode(inode); struct resv_map *resv_map; @@ -7374,8 +7382,16 @@ bool hugetlb_reserve_pages(struct inode return true; out_put_pages: - /* put back original number of pages, chg */ - (void)hugepage_subpool_put_pages(spool, chg); + spool_resv = chg - gbl_reserve; + if (spool_resv) { + /* put sub pool's reservation back, chg - gbl_reserve */ + gbl_resv = hugepage_subpool_put_pages(spool, spool_resv); + /* + * subpool's reserved pages can not be put back due to race, + * return to hstate. + */ + hugetlb_acct_memory(h, -gbl_resv); + } out_uncharge_cgroup: hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), chg * pages_per_huge_page(h), h_cg); _ Patches currently in -mm which might be from mawupeng1(a)huawei.com are

4 months, 1 week

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