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[PATCH AUTOSEL 4.9 01/13] bpf: do not blindly change rlimit in reuseport net selftest

by Sasha Levin

From: Eric Dumazet <edumazet(a)google.com> [ Upstream commit 262f9d811c7608f1e74258ceecfe1fa213bdf912 ] If the current process has unlimited RLIMIT_MEMLOCK, we should should leave it as is. Fixes: 941ff6f11c02 ("bpf: fix rlimit in reuseport net selftest") Signed-off-by: John Sperbeck <jsperbeck(a)google.com> Signed-off-by: Eric Dumazet <edumazet(a)google.com> Acked-by: Daniel Borkmann <daniel(a)iogearbox.net> Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/testing/selftests/net/reuseport_bpf.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/net/reuseport_bpf.c b/tools/testing/selftests/net/reuseport_bpf.c index cad14cd0ea92..b5277106df1f 100644 --- a/tools/testing/selftests/net/reuseport_bpf.c +++ b/tools/testing/selftests/net/reuseport_bpf.c @@ -437,14 +437,19 @@ void enable_fastopen(void) } } -static struct rlimit rlim_old, rlim_new; +static struct rlimit rlim_old; static __attribute__((constructor)) void main_ctor(void) { getrlimit(RLIMIT_MEMLOCK, &rlim_old); - rlim_new.rlim_cur = rlim_old.rlim_cur + (1UL << 20); - rlim_new.rlim_max = rlim_old.rlim_max + (1UL << 20); - setrlimit(RLIMIT_MEMLOCK, &rlim_new); + + if (rlim_old.rlim_cur != RLIM_INFINITY) { + struct rlimit rlim_new; + + rlim_new.rlim_cur = rlim_old.rlim_cur + (1UL << 20); + rlim_new.rlim_max = rlim_old.rlim_max + (1UL << 20); + setrlimit(RLIMIT_MEMLOCK, &rlim_new); + } } static __attribute__((destructor)) void main_dtor(void) -- 2.17.1

7 years

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[PATCH AUTOSEL 4.18 01/33] drm: fix use of freed memory in drm_mode_setcrtc

by Sasha Levin

From: Tomi Valkeinen <tomi.valkeinen(a)ti.com> [ Upstream commit 064253c1c0625efd0362a0b7ecdbe8bee2a2904d ] drm_mode_setcrtc() retries modesetting in case one of the functions it calls returns -EDEADLK. connector_set, mode and fb are freed before retrying, but they are not set to NULL. This can cause drm_mode_setcrtc() to use those variables. For example: On the first try __drm_mode_set_config_internal() returns -EDEADLK. connector_set, mode and fb are freed. Next retry starts, and drm_modeset_lock_all_ctx() returns -EDEADLK, and we jump to 'out'. The code will happily try to release all three again. This leads to crashes of different kinds, depending on the sequence the EDEADLKs happen. Fix this by setting the three variables to NULL at the start of the retry loop. Signed-off-by: Tomi Valkeinen <tomi.valkeinen(a)ti.com> Reviewed-by: Ville Syrjälä <ville.syrjala(a)linux.intel.com> Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20180917110054.4053-1-tomi.va… Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- drivers/gpu/drm/drm_crtc.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 98a36e6c69ad..bd207857a964 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -560,9 +560,9 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data, struct drm_mode_crtc *crtc_req = data; struct drm_crtc *crtc; struct drm_plane *plane; - struct drm_connector **connector_set = NULL, *connector; - struct drm_framebuffer *fb = NULL; - struct drm_display_mode *mode = NULL; + struct drm_connector **connector_set, *connector; + struct drm_framebuffer *fb; + struct drm_display_mode *mode; struct drm_mode_set set; uint32_t __user *set_connectors_ptr; struct drm_modeset_acquire_ctx ctx; @@ -591,6 +591,10 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data, mutex_lock(&crtc->dev->mode_config.mutex); drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE); retry: + connector_set = NULL; + fb = NULL; + mode = NULL; + ret = drm_modeset_lock_all_ctx(crtc->dev, &ctx); if (ret) goto out; -- 2.17.1

7 years

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[PATCH 2/2] selftests/ftrace: Fix synthetic event test to delete event correctly

by Steven Rostedt

From: Masami Hiramatsu <mhiramat(a)kernel.org> Fix the synthetic event test case to remove event correctly. If redirecting command to synthetic_event file without append mode, it cleans up all existing events and execute (parse) the command. This means "delete event" always fails to find the target event. Since previous synthetic event has a bug which doesn't return -ENOENT even if it fails to find the deleting event, this test passed. But fixing that bug, this test fails because this test itself has a bug. This fixes that bug by trying to delete event right after adding an event, and use append mode redirection ('>>') instead of normal redirection ('>'). Link: http://lkml.kernel.org/r/154013452832.25576.2305459545429386517.stgit@devbox Acked-by: Shuah Khan <shuah(a)kernel.org> Acked-by: Tom Zanussi <zanussi(a)linux.intel.com> Tested-by: Tom Zanussi <zanussi(a)linux.intel.com> Cc: Tom Zanussi <zanussi(a)kernel.org> Cc: Tom Zanussi <tom.zanussi(a)linux.intel.com> Cc: Rajvi Jingar <rajvi.jingar(a)intel.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: stable(a)vger.kernel.org Fixes: f06eec4d0f2c ('selftests: ftrace: Add inter-event hist triggers testcases') Signed-off-by: Masami Hiramatsu <mhiramat(a)kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org> --- .../trigger-synthetic-event-createremove.tc | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-createremove.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-createremove.tc index cef11377dcbd..c604438df13b 100644 --- a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-createremove.tc +++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-createremove.tc @@ -35,18 +35,18 @@ fi reset_trigger -echo "Test create synthetic event with an error" -echo 'wakeup_latency u64 lat pid_t pid char' > synthetic_events > /dev/null +echo "Test remove synthetic event" +echo '!wakeup_latency u64 lat pid_t pid char comm[16]' >> synthetic_events if [ -d events/synthetic/wakeup_latency ]; then - fail "Created wakeup_latency synthetic event with an invalid format" + fail "Failed to delete wakeup_latency synthetic event" fi reset_trigger -echo "Test remove synthetic event" -echo '!wakeup_latency u64 lat pid_t pid char comm[16]' > synthetic_events +echo "Test create synthetic event with an error" +echo 'wakeup_latency u64 lat pid_t pid char' > synthetic_events > /dev/null if [ -d events/synthetic/wakeup_latency ]; then - fail "Failed to delete wakeup_latency synthetic event" + fail "Created wakeup_latency synthetic event with an invalid format" fi do_reset -- 2.19.0

7 years

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[PATCH 1/2] tracing: Return -ENOENT if there is no target synthetic event

by Steven Rostedt

From: Masami Hiramatsu <mhiramat(a)kernel.org> Return -ENOENT error if there is no target synthetic event. This notices an operation failure to user as below; # echo 'wakeup_latency u64 lat; pid_t pid;' > synthetic_events # echo '!wakeup' >> synthetic_events sh: write error: No such file or directory Link: http://lkml.kernel.org/r/154013449986.25576.9487131386597290172.stgit@devbox Acked-by: Tom Zanussi <zanussi(a)linux.intel.com> Tested-by: Tom Zanussi <zanussi(a)linux.intel.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Rajvi Jingar <rajvi.jingar(a)intel.com> Cc: stable(a)vger.kernel.org Fixes: 4b147936fa50 ('tracing: Add support for 'synthetic' events') Signed-off-by: Masami Hiramatsu <mhiramat(a)kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org> --- kernel/trace/trace_events_hist.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index d239004aaf29..eb908ef2ecec 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1063,8 +1063,10 @@ static int create_synth_event(int argc, char **argv) event = NULL; ret = -EEXIST; goto out; - } else if (delete_event) + } else if (delete_event) { + ret = -ENOENT; goto out; + } if (argc < 2) { ret = -EINVAL; -- 2.19.0

7 years

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[PATCH] serial: sh-sci: Fix could not remove dev_attr_rx_fifo_timeout

by Yoshihiro Shimoda

This patch fixes an issue that the sci_remove() could not remove dev_attr_rx_fifo_timeout because uart_remove_one_port() set the port->port.type to PORT_UNKNOWN. Reported-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym(a)renesas.com> Fixes: 5d23188a473d ("serial: sh-sci: make RX FIFO parameters tunable via sysfs") Cc: <stable(a)vger.kernel.org> # v4.11+ Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh(a)renesas.com> --- drivers/tty/serial/sh-sci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index ab3f6e91..3649b83 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -3102,6 +3102,7 @@ static inline int sci_probe_earlyprintk(struct platform_device *pdev) static int sci_remove(struct platform_device *dev) { struct sci_port *port = platform_get_drvdata(dev); + unsigned int type = port->port.type; /* uart_remove_... clears it */ sci_ports_in_use &= ~BIT(port->port.line); uart_remove_one_port(&sci_uart_driver, &port->port); @@ -3112,8 +3113,7 @@ static int sci_remove(struct platform_device *dev) sysfs_remove_file(&dev->dev.kobj, &dev_attr_rx_fifo_trigger.attr); } - if (port->port.type == PORT_SCIFA || port->port.type == PORT_SCIFB || - port->port.type == PORT_HSCIF) { + if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF) { sysfs_remove_file(&dev->dev.kobj, &dev_attr_rx_fifo_timeout.attr); } -- 1.9.1

7 years

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[PATCH] drm/ast: fixed cursor may disappear sometimes

by Y.C. Chen

From: "Y.C. Chen" <yc_chen(a)aspeedtech.com> Signed-off-by: Y.C. Chen <yc_chen(a)aspeedtech.com> --- drivers/gpu/drm/ast/ast_mode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index 5e77d45..4e079d4 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -1254,7 +1254,7 @@ static int ast_cursor_move(struct drm_crtc *crtc, ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xc7, ((y >> 8) & 0x07)); /* dummy write to fire HWC */ - ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xCB, 0xFF, 0x00); + ast_show_cursor(crtc); return 0; } -- 1.8.3.1

7 years

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[PATCH] xtensa: add NOTES section to the linker script

by Max Filippov

This section collects all source .note.* sections together in the vmlinux image. Without it .note.Linux section may be placed at address 0, while the rest of the kernel is at its normal address, resulting in a huge vmlinux.bin image that may not be linked into the xtensa Image.elf. Cc: stable(a)vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc(a)gmail.com> --- arch/xtensa/boot/Makefile | 2 +- arch/xtensa/kernel/vmlinux.lds.S | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/xtensa/boot/Makefile b/arch/xtensa/boot/Makefile index dc9e0ba7122c..294846117fc2 100644 --- a/arch/xtensa/boot/Makefile +++ b/arch/xtensa/boot/Makefile @@ -33,7 +33,7 @@ uImage: $(obj)/uImage boot-elf boot-redboot: $(addprefix $(obj)/,$(subdir-y)) $(Q)$(MAKE) $(build)=$(obj)/$@ $(MAKECMDGOALS) -OBJCOPYFLAGS = --strip-all -R .comment -R .note.gnu.build-id -O binary +OBJCOPYFLAGS = --strip-all -R .comment -R .notes -O binary vmlinux.bin: vmlinux FORCE $(call if_changed,objcopy) diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S index a1c3edb8ad56..fa926995d2a3 100644 --- a/arch/xtensa/kernel/vmlinux.lds.S +++ b/arch/xtensa/kernel/vmlinux.lds.S @@ -131,6 +131,7 @@ SECTIONS .fixup : { *(.fixup) } EXCEPTION_TABLE(16) + NOTES /* Data section */ _sdata = .; -- 2.11.0

7 years

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[merged] hugetlbfs-dirty-pages-as-they-are-added-to-pagecache-v2.patch removed from -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: hugetlbfs: dirty pages as they are added to pagecache has been removed from the -mm tree. Its filename was hugetlbfs-dirty-pages-as-they-are-added-to-pagecache-v2.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Mike Kravetz <mike.kravetz(a)oracle.com> Subject: hugetlbfs: dirty pages as they are added to pagecache Some test systems were experiencing negative huge page reserve counts and incorrect file block counts. This was traced to /proc/sys/vm/drop_caches removing clean pages from hugetlbfs file pagecaches. When non-hugetlbfs explicit code removes the pages, the appropriate accounting is not performed. This can be recreated as follows: fallocate -l 2M /dev/hugepages/foo echo 1 > /proc/sys/vm/drop_caches fallocate -l 2M /dev/hugepages/foo grep -i huge /proc/meminfo AnonHugePages: 0 kB ShmemHugePages: 0 kB HugePages_Total: 2048 HugePages_Free: 2047 HugePages_Rsvd: 18446744073709551615 HugePages_Surp: 0 Hugepagesize: 2048 kB Hugetlb: 4194304 kB ls -lsh /dev/hugepages/foo 4.0M -rw-r--r--. 1 root root 2.0M Oct 17 20:05 /dev/hugepages/foo To address this issue, dirty pages as they are added to pagecache. This can easily be reproduced with fallocate as shown above. Read faulted pages will eventually end up being marked dirty. But there is a window where they are clean and could be impacted by code such as drop_caches. So, just dirty them all as they are added to the pagecache. Link: http://lkml.kernel.org/r/b5be45b8-5afe-56cd-9482-28384699a049@oracle.com Fixes: 6bda666a03f0 ("hugepages: fold find_or_alloc_pages into huge_no_page()") Signed-off-by: Mike Kravetz <mike.kravetz(a)oracle.com> Acked-by: Mihcla Hocko <mhocko(a)suse.com> Reviewed-by: Khalid Aziz <khalid.aziz(a)oracle.com> Cc: Hugh Dickins <hughd(a)google.com> Cc: Naoya Horiguchi <n-horiguchi(a)ah.jp.nec.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar(a)linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange(a)redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov(a)linux.intel.com> Cc: Davidlohr Bueso <dave(a)stgolabs.net> Cc: Alexander Viro <viro(a)zeniv.linux.org.uk> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/hugetlb.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/mm/hugetlb.c~hugetlbfs-dirty-pages-as-they-are-added-to-pagecache-v2 +++ a/mm/hugetlb.c @@ -3690,6 +3690,12 @@ int huge_add_to_page_cache(struct page * return err; ClearPagePrivate(page); + /* + * set page dirty so that it will not be removed from cache/file + * by non-hugetlbfs specific code paths. + */ + set_page_dirty(page); + spin_lock(&inode->i_lock); inode->i_blocks += blocks_per_huge_page(h); spin_unlock(&inode->i_lock); _ Patches currently in -mm which might be from mike.kravetz(a)oracle.com are

7 years

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[merged] userfaultfd-disable-irqs-when-taking-the-waitqueue-lock.patch removed from -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: userfaultfd: disable irqs when taking the waitqueue lock has been removed from the -mm tree. Its filename was userfaultfd-disable-irqs-when-taking-the-waitqueue-lock.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Christoph Hellwig <hch(a)lst.de> Subject: userfaultfd: disable irqs when taking the waitqueue lock userfaultfd contains howe-grown locking of the waitqueue lock, and does not disable interrupts. This relies on the fact that no one else takes it from interrupt context and violates an invariat of the normal waitqueue locking scheme. With aio poll it is easy to trigger other locks that disable interrupts (or are called from interrupt context). Link: http://lkml.kernel.org/r/20181018154101.18750-1-hch@lst.de Signed-off-by: Christoph Hellwig <hch(a)lst.de> Reviewed-by: Andrea Arcangeli <aarcange(a)redhat.com> Reviewed-by: Andrew Morton <akpm(a)linux-foundation.org> Cc: <stable(a)vger.kernel.org> [4.19.x] Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- fs/userfaultfd.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/fs/userfaultfd.c~userfaultfd-disable-irqs-when-taking-the-waitqueue-lock +++ a/fs/userfaultfd.c @@ -1026,7 +1026,7 @@ static ssize_t userfaultfd_ctx_read(stru struct userfaultfd_ctx *fork_nctx = NULL; /* always take the fd_wqh lock before the fault_pending_wqh lock */ - spin_lock(&ctx->fd_wqh.lock); + spin_lock_irq(&ctx->fd_wqh.lock); __add_wait_queue(&ctx->fd_wqh, &wait); for (;;) { set_current_state(TASK_INTERRUPTIBLE); @@ -1112,13 +1112,13 @@ static ssize_t userfaultfd_ctx_read(stru ret = -EAGAIN; break; } - spin_unlock(&ctx->fd_wqh.lock); + spin_unlock_irq(&ctx->fd_wqh.lock); schedule(); - spin_lock(&ctx->fd_wqh.lock); + spin_lock_irq(&ctx->fd_wqh.lock); } __remove_wait_queue(&ctx->fd_wqh, &wait); __set_current_state(TASK_RUNNING); - spin_unlock(&ctx->fd_wqh.lock); + spin_unlock_irq(&ctx->fd_wqh.lock); if (!ret && msg->event == UFFD_EVENT_FORK) { ret = resolve_userfault_fork(ctx, fork_nctx, msg); _ Patches currently in -mm which might be from hch(a)lst.de are

7 years

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[merged] mm-proc-pid-smaps_rollup-fix-null-pointer-deref-in-smaps_pte_range.patch removed from -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: mm: /proc/pid/smaps_rollup: fix NULL pointer deref in smaps_pte_range() has been removed from the -mm tree. Its filename was mm-proc-pid-smaps_rollup-fix-null-pointer-deref-in-smaps_pte_range.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Vlastimil Babka <vbabka(a)suse.cz> Subject: mm: /proc/pid/smaps_rollup: fix NULL pointer deref in smaps_pte_range() Leonardo reports an apparent regression in 4.19-rc7: BUG: unable to handle kernel NULL pointer dereference at 00000000000000f0 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 3 PID: 6032 Comm: python Not tainted 4.19.0-041900rc7-lowlatency #201810071631 Hardware name: LENOVO 80UG/Toronto 4A2, BIOS 0XCN45WW 08/09/2018 RIP: 0010:smaps_pte_range+0x32d/0x540 Code: 80 00 00 00 00 74 a9 48 89 de 41 f6 40 52 40 0f 85 04 02 00 00 49 2b 30 48 c1 ee 0c 49 03 b0 98 00 00 00 49 8b 80 a0 00 00 00 <48> 8b b8 f0 00 00 00 e8 b7 ef ec ff 48 85 c0 0f 84 71 ff ff ff a8 RSP: 0018:ffffb0cbc484fb88 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000560ddb9e9000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000560ddb9e9 RDI: 0000000000000001 RBP: ffffb0cbc484fbc0 R08: ffff94a5a227a578 R09: ffff94a5a227a578 R10: 0000000000000000 R11: 0000560ddbbe7000 R12: ffffe903098ba728 R13: ffffb0cbc484fc78 R14: ffffb0cbc484fcf8 R15: ffff94a5a2e9cf48 FS: 00007f6dfb683740(0000) GS:ffff94a5aaf80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000f0 CR3: 000000011c118001 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __walk_page_range+0x3c2/0x6f0 walk_page_vma+0x42/0x60 smap_gather_stats+0x79/0xe0 ? gather_pte_stats+0x320/0x320 ? gather_hugetlb_stats+0x70/0x70 show_smaps_rollup+0xcd/0x1c0 seq_read+0x157/0x400 __vfs_read+0x3a/0x180 ? security_file_permission+0x93/0xc0 ? security_file_permission+0x93/0xc0 vfs_read+0x8f/0x140 ksys_read+0x55/0xc0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x5a/0x110 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Decoded code matched to local compilation+disassembly points to smaps_pte_entry(): } else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap && pte_none(*pte))) { page = find_get_entry(vma->vm_file->f_mapping, linear_page_index(vma, addr)); Here, vma->vm_file is NULL. mss->check_shmem_swap should be false in that case, however for smaps_rollup, smap_gather_stats() can set the flag true for one vma and leave it true for subsequent vma's where it should be false. To fix, reset the check_shmem_swap flag to false. There's also related bug which sets mss->swap to shmem_swapped, which in the context of smaps_rollup overwrites any value accumulated from previous vma's. Fix that as well. Note that the report suggests a regression between 4.17.19 and 4.19-rc7, which makes the 4.19 series ending with commit 258f669e7e88 ("mm: /proc/pid/smaps_rollup: convert to single value seq_file") suspicious. But the mss was reused for rollup since 493b0e9d945f ("mm: add /proc/pid/smaps_rollup") so let's play it safe with the stable backport. Link: http://lkml.kernel.org/r/555fbd1f-4ac9-0b58-dcd4-5dc4380ff7ca@suse.cz Link: https://bugzilla.kernel.org/show_bug.cgi?id=201377 Fixes: 493b0e9d945f ("mm: add /proc/pid/smaps_rollup") Signed-off-by: Vlastimil Babka <vbabka(a)suse.cz> Reported-by: Leonardo Soares Müller <leozinho29_eu(a)hotmail.com> Tested-by: Leonardo Soares Müller <leozinho29_eu(a)hotmail.com> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Daniel Colascione <dancol(a)google.com> Cc: Alexey Dobriyan <adobriyan(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- fs/proc/task_mmu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/fs/proc/task_mmu.c~mm-proc-pid-smaps_rollup-fix-null-pointer-deref-in-smaps_pte_range +++ a/fs/proc/task_mmu.c @@ -713,6 +713,8 @@ static void smap_gather_stats(struct vm_ smaps_walk.private = mss; #ifdef CONFIG_SHMEM + /* In case of smaps_rollup, reset the value from previous vma */ + mss->check_shmem_swap = false; if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) { /* * For shared or readonly shmem mappings we know that all @@ -728,7 +730,7 @@ static void smap_gather_stats(struct vm_ if (!shmem_swapped || (vma->vm_flags & VM_SHARED) || !(vma->vm_flags & VM_WRITE)) { - mss->swap = shmem_swapped; + mss->swap += shmem_swapped; } else { mss->check_shmem_swap = true; smaps_walk.pte_hole = smaps_pte_hole; _ Patches currently in -mm which might be from vbabka(a)suse.cz are

7 years

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