February 2024 - Linux-stable-mirror

FAILED: patch "[PATCH] nilfs2: fix potential bug in end_buffer_async_write" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-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-4.19.y git checkout FETCH_HEAD git cherry-pick -x 5bc09b397cbf1221f8a8aacb1152650c9195b02b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021950-voltage-culprit-3dd5@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: 5bc09b397cbf ("nilfs2: fix potential bug in end_buffer_async_write") ff5710c3f3c2 ("nilfs2: convert nilfs_segctor_prepare_write to use folios") 3cd36212bf75 ("nilfs2: convert nilfs_segctor_complete_write to use folios") 50196f0081ca ("nilfs2: convert nilfs_abort_logs to use folios") 8f46eaf6fd84 ("nilfs2: add nilfs_end_folio_io()") 679bd7ebdd31 ("nilfs2: fix buffer corruption due to concurrent device reads") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 5bc09b397cbf1221f8a8aacb1152650c9195b02b Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Date: Sun, 4 Feb 2024 01:16:45 +0900 Subject: [PATCH] nilfs2: fix potential bug in end_buffer_async_write According to a syzbot report, end_buffer_async_write(), which handles the completion of block device writes, may detect abnormal condition of the buffer async_write flag and cause a BUG_ON failure when using nilfs2. Nilfs2 itself does not use end_buffer_async_write(). But, the async_write flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") as a means of resolving double list insertion of dirty blocks in nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the resulting crash. This modification is safe as long as it is used for file data and b-tree node blocks where the page caches are independent. However, it was irrelevant and redundant to also introduce async_write for segment summary and super root blocks that share buffers with the backing device. This led to the possibility that the BUG_ON check in end_buffer_async_write would fail as described above, if independent writebacks of the backing device occurred in parallel. The use of async_write for segment summary buffers has already been removed in a previous change. Fix this issue by removing the manipulation of the async_write flag for the remaining super root block buffer. Link: https://lkml.kernel.org/r/20240203161645.4992-1-konishi.ryusuke@gmail.com Fixes: 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+5c04210f7c7f897c1e7f(a)syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000019a97c05fd42f8c8@google.com Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 2590a0860eab..2bfb08052d39 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -1703,7 +1703,6 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - set_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { if (bh->b_folio != bd_folio) { folio_lock(bd_folio); @@ -1714,6 +1713,7 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) } break; } + set_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_begin_folio_io(fs_folio); fs_folio = bh->b_folio; @@ -1800,7 +1800,6 @@ static void nilfs_abort_logs(struct list_head *logs, int err) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - clear_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { clear_buffer_uptodate(bh); if (bh->b_folio != bd_folio) { @@ -1809,6 +1808,7 @@ static void nilfs_abort_logs(struct list_head *logs, int err) } break; } + clear_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, err); fs_folio = bh->b_folio; @@ -1896,8 +1896,9 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) BIT(BH_Delay) | BIT(BH_NILFS_Volatile) | BIT(BH_NILFS_Redirected)); - set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh == segbuf->sb_super_root) { + set_buffer_uptodate(bh); + clear_buffer_dirty(bh); if (bh->b_folio != bd_folio) { folio_end_writeback(bd_folio); bd_folio = bh->b_folio; @@ -1905,6 +1906,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) update_sr = true; break; } + set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, 0); fs_folio = bh->b_folio;

1 year

1
0
0 0

FAILED: patch "[PATCH] nilfs2: fix potential bug in end_buffer_async_write" 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 5bc09b397cbf1221f8a8aacb1152650c9195b02b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021948-sacrifice-superior-85e5@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: 5bc09b397cbf ("nilfs2: fix potential bug in end_buffer_async_write") ff5710c3f3c2 ("nilfs2: convert nilfs_segctor_prepare_write to use folios") 3cd36212bf75 ("nilfs2: convert nilfs_segctor_complete_write to use folios") 50196f0081ca ("nilfs2: convert nilfs_abort_logs to use folios") 8f46eaf6fd84 ("nilfs2: add nilfs_end_folio_io()") 679bd7ebdd31 ("nilfs2: fix buffer corruption due to concurrent device reads") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 5bc09b397cbf1221f8a8aacb1152650c9195b02b Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Date: Sun, 4 Feb 2024 01:16:45 +0900 Subject: [PATCH] nilfs2: fix potential bug in end_buffer_async_write According to a syzbot report, end_buffer_async_write(), which handles the completion of block device writes, may detect abnormal condition of the buffer async_write flag and cause a BUG_ON failure when using nilfs2. Nilfs2 itself does not use end_buffer_async_write(). But, the async_write flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") as a means of resolving double list insertion of dirty blocks in nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the resulting crash. This modification is safe as long as it is used for file data and b-tree node blocks where the page caches are independent. However, it was irrelevant and redundant to also introduce async_write for segment summary and super root blocks that share buffers with the backing device. This led to the possibility that the BUG_ON check in end_buffer_async_write would fail as described above, if independent writebacks of the backing device occurred in parallel. The use of async_write for segment summary buffers has already been removed in a previous change. Fix this issue by removing the manipulation of the async_write flag for the remaining super root block buffer. Link: https://lkml.kernel.org/r/20240203161645.4992-1-konishi.ryusuke@gmail.com Fixes: 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+5c04210f7c7f897c1e7f(a)syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000019a97c05fd42f8c8@google.com Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 2590a0860eab..2bfb08052d39 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -1703,7 +1703,6 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - set_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { if (bh->b_folio != bd_folio) { folio_lock(bd_folio); @@ -1714,6 +1713,7 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) } break; } + set_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_begin_folio_io(fs_folio); fs_folio = bh->b_folio; @@ -1800,7 +1800,6 @@ static void nilfs_abort_logs(struct list_head *logs, int err) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - clear_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { clear_buffer_uptodate(bh); if (bh->b_folio != bd_folio) { @@ -1809,6 +1808,7 @@ static void nilfs_abort_logs(struct list_head *logs, int err) } break; } + clear_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, err); fs_folio = bh->b_folio; @@ -1896,8 +1896,9 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) BIT(BH_Delay) | BIT(BH_NILFS_Volatile) | BIT(BH_NILFS_Redirected)); - set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh == segbuf->sb_super_root) { + set_buffer_uptodate(bh); + clear_buffer_dirty(bh); if (bh->b_folio != bd_folio) { folio_end_writeback(bd_folio); bd_folio = bh->b_folio; @@ -1905,6 +1906,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) update_sr = true; break; } + set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, 0); fs_folio = bh->b_folio;

1 year

1
0
0 0

FAILED: patch "[PATCH] nilfs2: fix potential bug in end_buffer_async_write" 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 5bc09b397cbf1221f8a8aacb1152650c9195b02b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021947-stays-preflight-796b@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: 5bc09b397cbf ("nilfs2: fix potential bug in end_buffer_async_write") ff5710c3f3c2 ("nilfs2: convert nilfs_segctor_prepare_write to use folios") 3cd36212bf75 ("nilfs2: convert nilfs_segctor_complete_write to use folios") 50196f0081ca ("nilfs2: convert nilfs_abort_logs to use folios") 8f46eaf6fd84 ("nilfs2: add nilfs_end_folio_io()") 679bd7ebdd31 ("nilfs2: fix buffer corruption due to concurrent device reads") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 5bc09b397cbf1221f8a8aacb1152650c9195b02b Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Date: Sun, 4 Feb 2024 01:16:45 +0900 Subject: [PATCH] nilfs2: fix potential bug in end_buffer_async_write According to a syzbot report, end_buffer_async_write(), which handles the completion of block device writes, may detect abnormal condition of the buffer async_write flag and cause a BUG_ON failure when using nilfs2. Nilfs2 itself does not use end_buffer_async_write(). But, the async_write flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") as a means of resolving double list insertion of dirty blocks in nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the resulting crash. This modification is safe as long as it is used for file data and b-tree node blocks where the page caches are independent. However, it was irrelevant and redundant to also introduce async_write for segment summary and super root blocks that share buffers with the backing device. This led to the possibility that the BUG_ON check in end_buffer_async_write would fail as described above, if independent writebacks of the backing device occurred in parallel. The use of async_write for segment summary buffers has already been removed in a previous change. Fix this issue by removing the manipulation of the async_write flag for the remaining super root block buffer. Link: https://lkml.kernel.org/r/20240203161645.4992-1-konishi.ryusuke@gmail.com Fixes: 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+5c04210f7c7f897c1e7f(a)syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000019a97c05fd42f8c8@google.com Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 2590a0860eab..2bfb08052d39 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -1703,7 +1703,6 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - set_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { if (bh->b_folio != bd_folio) { folio_lock(bd_folio); @@ -1714,6 +1713,7 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) } break; } + set_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_begin_folio_io(fs_folio); fs_folio = bh->b_folio; @@ -1800,7 +1800,6 @@ static void nilfs_abort_logs(struct list_head *logs, int err) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - clear_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { clear_buffer_uptodate(bh); if (bh->b_folio != bd_folio) { @@ -1809,6 +1808,7 @@ static void nilfs_abort_logs(struct list_head *logs, int err) } break; } + clear_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, err); fs_folio = bh->b_folio; @@ -1896,8 +1896,9 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) BIT(BH_Delay) | BIT(BH_NILFS_Volatile) | BIT(BH_NILFS_Redirected)); - set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh == segbuf->sb_super_root) { + set_buffer_uptodate(bh); + clear_buffer_dirty(bh); if (bh->b_folio != bd_folio) { folio_end_writeback(bd_folio); bd_folio = bh->b_folio; @@ -1905,6 +1906,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) update_sr = true; break; } + set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, 0); fs_folio = bh->b_folio;

1 year

1
0
0 0

FAILED: patch "[PATCH] nilfs2: fix potential bug in end_buffer_async_write" 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 5bc09b397cbf1221f8a8aacb1152650c9195b02b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021945-output-concave-3ad1@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: 5bc09b397cbf ("nilfs2: fix potential bug in end_buffer_async_write") ff5710c3f3c2 ("nilfs2: convert nilfs_segctor_prepare_write to use folios") 3cd36212bf75 ("nilfs2: convert nilfs_segctor_complete_write to use folios") 50196f0081ca ("nilfs2: convert nilfs_abort_logs to use folios") 8f46eaf6fd84 ("nilfs2: add nilfs_end_folio_io()") 679bd7ebdd31 ("nilfs2: fix buffer corruption due to concurrent device reads") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 5bc09b397cbf1221f8a8aacb1152650c9195b02b Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Date: Sun, 4 Feb 2024 01:16:45 +0900 Subject: [PATCH] nilfs2: fix potential bug in end_buffer_async_write According to a syzbot report, end_buffer_async_write(), which handles the completion of block device writes, may detect abnormal condition of the buffer async_write flag and cause a BUG_ON failure when using nilfs2. Nilfs2 itself does not use end_buffer_async_write(). But, the async_write flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") as a means of resolving double list insertion of dirty blocks in nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the resulting crash. This modification is safe as long as it is used for file data and b-tree node blocks where the page caches are independent. However, it was irrelevant and redundant to also introduce async_write for segment summary and super root blocks that share buffers with the backing device. This led to the possibility that the BUG_ON check in end_buffer_async_write would fail as described above, if independent writebacks of the backing device occurred in parallel. The use of async_write for segment summary buffers has already been removed in a previous change. Fix this issue by removing the manipulation of the async_write flag for the remaining super root block buffer. Link: https://lkml.kernel.org/r/20240203161645.4992-1-konishi.ryusuke@gmail.com Fixes: 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+5c04210f7c7f897c1e7f(a)syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000019a97c05fd42f8c8@google.com Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 2590a0860eab..2bfb08052d39 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -1703,7 +1703,6 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - set_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { if (bh->b_folio != bd_folio) { folio_lock(bd_folio); @@ -1714,6 +1713,7 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) } break; } + set_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_begin_folio_io(fs_folio); fs_folio = bh->b_folio; @@ -1800,7 +1800,6 @@ static void nilfs_abort_logs(struct list_head *logs, int err) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - clear_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { clear_buffer_uptodate(bh); if (bh->b_folio != bd_folio) { @@ -1809,6 +1808,7 @@ static void nilfs_abort_logs(struct list_head *logs, int err) } break; } + clear_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, err); fs_folio = bh->b_folio; @@ -1896,8 +1896,9 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) BIT(BH_Delay) | BIT(BH_NILFS_Volatile) | BIT(BH_NILFS_Redirected)); - set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh == segbuf->sb_super_root) { + set_buffer_uptodate(bh); + clear_buffer_dirty(bh); if (bh->b_folio != bd_folio) { folio_end_writeback(bd_folio); bd_folio = bh->b_folio; @@ -1905,6 +1906,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) update_sr = true; break; } + set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, 0); fs_folio = bh->b_folio;

1 year

1
0
0 0

FAILED: patch "[PATCH] nilfs2: fix potential bug in end_buffer_async_write" 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 5bc09b397cbf1221f8a8aacb1152650c9195b02b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021944-impolite-substance-4bc0@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: 5bc09b397cbf ("nilfs2: fix potential bug in end_buffer_async_write") ff5710c3f3c2 ("nilfs2: convert nilfs_segctor_prepare_write to use folios") 3cd36212bf75 ("nilfs2: convert nilfs_segctor_complete_write to use folios") 50196f0081ca ("nilfs2: convert nilfs_abort_logs to use folios") 8f46eaf6fd84 ("nilfs2: add nilfs_end_folio_io()") 679bd7ebdd31 ("nilfs2: fix buffer corruption due to concurrent device reads") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 5bc09b397cbf1221f8a8aacb1152650c9195b02b Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Date: Sun, 4 Feb 2024 01:16:45 +0900 Subject: [PATCH] nilfs2: fix potential bug in end_buffer_async_write According to a syzbot report, end_buffer_async_write(), which handles the completion of block device writes, may detect abnormal condition of the buffer async_write flag and cause a BUG_ON failure when using nilfs2. Nilfs2 itself does not use end_buffer_async_write(). But, the async_write flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") as a means of resolving double list insertion of dirty blocks in nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the resulting crash. This modification is safe as long as it is used for file data and b-tree node blocks where the page caches are independent. However, it was irrelevant and redundant to also introduce async_write for segment summary and super root blocks that share buffers with the backing device. This led to the possibility that the BUG_ON check in end_buffer_async_write would fail as described above, if independent writebacks of the backing device occurred in parallel. The use of async_write for segment summary buffers has already been removed in a previous change. Fix this issue by removing the manipulation of the async_write flag for the remaining super root block buffer. Link: https://lkml.kernel.org/r/20240203161645.4992-1-konishi.ryusuke@gmail.com Fixes: 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+5c04210f7c7f897c1e7f(a)syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000019a97c05fd42f8c8@google.com Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 2590a0860eab..2bfb08052d39 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -1703,7 +1703,6 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - set_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { if (bh->b_folio != bd_folio) { folio_lock(bd_folio); @@ -1714,6 +1713,7 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) } break; } + set_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_begin_folio_io(fs_folio); fs_folio = bh->b_folio; @@ -1800,7 +1800,6 @@ static void nilfs_abort_logs(struct list_head *logs, int err) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - clear_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { clear_buffer_uptodate(bh); if (bh->b_folio != bd_folio) { @@ -1809,6 +1808,7 @@ static void nilfs_abort_logs(struct list_head *logs, int err) } break; } + clear_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, err); fs_folio = bh->b_folio; @@ -1896,8 +1896,9 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) BIT(BH_Delay) | BIT(BH_NILFS_Volatile) | BIT(BH_NILFS_Redirected)); - set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh == segbuf->sb_super_root) { + set_buffer_uptodate(bh); + clear_buffer_dirty(bh); if (bh->b_folio != bd_folio) { folio_end_writeback(bd_folio); bd_folio = bh->b_folio; @@ -1905,6 +1906,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) update_sr = true; break; } + set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, 0); fs_folio = bh->b_folio;

1 year

1
0
0 0

FAILED: patch "[PATCH] nilfs2: fix potential bug in end_buffer_async_write" 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 5bc09b397cbf1221f8a8aacb1152650c9195b02b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021942-tabloid-clarinet-50d2@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: 5bc09b397cbf ("nilfs2: fix potential bug in end_buffer_async_write") ff5710c3f3c2 ("nilfs2: convert nilfs_segctor_prepare_write to use folios") 3cd36212bf75 ("nilfs2: convert nilfs_segctor_complete_write to use folios") 50196f0081ca ("nilfs2: convert nilfs_abort_logs to use folios") 8f46eaf6fd84 ("nilfs2: add nilfs_end_folio_io()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 5bc09b397cbf1221f8a8aacb1152650c9195b02b Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Date: Sun, 4 Feb 2024 01:16:45 +0900 Subject: [PATCH] nilfs2: fix potential bug in end_buffer_async_write According to a syzbot report, end_buffer_async_write(), which handles the completion of block device writes, may detect abnormal condition of the buffer async_write flag and cause a BUG_ON failure when using nilfs2. Nilfs2 itself does not use end_buffer_async_write(). But, the async_write flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") as a means of resolving double list insertion of dirty blocks in nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the resulting crash. This modification is safe as long as it is used for file data and b-tree node blocks where the page caches are independent. However, it was irrelevant and redundant to also introduce async_write for segment summary and super root blocks that share buffers with the backing device. This led to the possibility that the BUG_ON check in end_buffer_async_write would fail as described above, if independent writebacks of the backing device occurred in parallel. The use of async_write for segment summary buffers has already been removed in a previous change. Fix this issue by removing the manipulation of the async_write flag for the remaining super root block buffer. Link: https://lkml.kernel.org/r/20240203161645.4992-1-konishi.ryusuke@gmail.com Fixes: 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+5c04210f7c7f897c1e7f(a)syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000019a97c05fd42f8c8@google.com Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 2590a0860eab..2bfb08052d39 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -1703,7 +1703,6 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - set_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { if (bh->b_folio != bd_folio) { folio_lock(bd_folio); @@ -1714,6 +1713,7 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) } break; } + set_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_begin_folio_io(fs_folio); fs_folio = bh->b_folio; @@ -1800,7 +1800,6 @@ static void nilfs_abort_logs(struct list_head *logs, int err) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - clear_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { clear_buffer_uptodate(bh); if (bh->b_folio != bd_folio) { @@ -1809,6 +1808,7 @@ static void nilfs_abort_logs(struct list_head *logs, int err) } break; } + clear_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, err); fs_folio = bh->b_folio; @@ -1896,8 +1896,9 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) BIT(BH_Delay) | BIT(BH_NILFS_Volatile) | BIT(BH_NILFS_Redirected)); - set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh == segbuf->sb_super_root) { + set_buffer_uptodate(bh); + clear_buffer_dirty(bh); if (bh->b_folio != bd_folio) { folio_end_writeback(bd_folio); bd_folio = bh->b_folio; @@ -1905,6 +1906,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) update_sr = true; break; } + set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, 0); fs_folio = bh->b_folio;

1 year

1
0
0 0

FAILED: patch "[PATCH] nilfs2: fix potential bug in end_buffer_async_write" failed to apply to 6.7-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.7-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-6.7.y git checkout FETCH_HEAD git cherry-pick -x 5bc09b397cbf1221f8a8aacb1152650c9195b02b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021941-aerobics-disliking-5751@gregkh' --subject-prefix 'PATCH 6.7.y' HEAD^.. Possible dependencies: 5bc09b397cbf ("nilfs2: fix potential bug in end_buffer_async_write") ff5710c3f3c2 ("nilfs2: convert nilfs_segctor_prepare_write to use folios") 3cd36212bf75 ("nilfs2: convert nilfs_segctor_complete_write to use folios") 50196f0081ca ("nilfs2: convert nilfs_abort_logs to use folios") 8f46eaf6fd84 ("nilfs2: add nilfs_end_folio_io()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 5bc09b397cbf1221f8a8aacb1152650c9195b02b Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Date: Sun, 4 Feb 2024 01:16:45 +0900 Subject: [PATCH] nilfs2: fix potential bug in end_buffer_async_write According to a syzbot report, end_buffer_async_write(), which handles the completion of block device writes, may detect abnormal condition of the buffer async_write flag and cause a BUG_ON failure when using nilfs2. Nilfs2 itself does not use end_buffer_async_write(). But, the async_write flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") as a means of resolving double list insertion of dirty blocks in nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the resulting crash. This modification is safe as long as it is used for file data and b-tree node blocks where the page caches are independent. However, it was irrelevant and redundant to also introduce async_write for segment summary and super root blocks that share buffers with the backing device. This led to the possibility that the BUG_ON check in end_buffer_async_write would fail as described above, if independent writebacks of the backing device occurred in parallel. The use of async_write for segment summary buffers has already been removed in a previous change. Fix this issue by removing the manipulation of the async_write flag for the remaining super root block buffer. Link: https://lkml.kernel.org/r/20240203161645.4992-1-konishi.ryusuke@gmail.com Fixes: 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+5c04210f7c7f897c1e7f(a)syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000019a97c05fd42f8c8@google.com Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 2590a0860eab..2bfb08052d39 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -1703,7 +1703,6 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - set_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { if (bh->b_folio != bd_folio) { folio_lock(bd_folio); @@ -1714,6 +1713,7 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) } break; } + set_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_begin_folio_io(fs_folio); fs_folio = bh->b_folio; @@ -1800,7 +1800,6 @@ static void nilfs_abort_logs(struct list_head *logs, int err) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - clear_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { clear_buffer_uptodate(bh); if (bh->b_folio != bd_folio) { @@ -1809,6 +1808,7 @@ static void nilfs_abort_logs(struct list_head *logs, int err) } break; } + clear_buffer_async_write(bh); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, err); fs_folio = bh->b_folio; @@ -1896,8 +1896,9 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) BIT(BH_Delay) | BIT(BH_NILFS_Volatile) | BIT(BH_NILFS_Redirected)); - set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh == segbuf->sb_super_root) { + set_buffer_uptodate(bh); + clear_buffer_dirty(bh); if (bh->b_folio != bd_folio) { folio_end_writeback(bd_folio); bd_folio = bh->b_folio; @@ -1905,6 +1906,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) update_sr = true; break; } + set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh->b_folio != fs_folio) { nilfs_end_folio_io(fs_folio, 0); fs_folio = bh->b_folio;

1 year

1
0
0 0

[PATCH 6.6 6.7] nilfs2: fix hang in nilfs_lookup_dirty_data_buffers()

by Ryusuke Konishi

commit 38296afe3c6ee07319e01bb249aa4bb47c07b534 upstream. Syzbot reported a hang issue in migrate_pages_batch() called by mbind() and nilfs_lookup_dirty_data_buffers() called in the log writer of nilfs2. While migrate_pages_batch() locks a folio and waits for the writeback to complete, the log writer thread that should bring the writeback to completion picks up the folio being written back in nilfs_lookup_dirty_data_buffers() that it calls for subsequent log creation and was trying to lock the folio. Thus causing a deadlock. In the first place, it is unexpected that folios/pages in the middle of writeback will be updated and become dirty. Nilfs2 adds a checksum to verify the validity of the log being written and uses it for recovery at mount, so data changes during writeback are suppressed. Since this is broken, an unclean shutdown could potentially cause recovery to fail. Investigation revealed that the root cause is that the wait for writeback completion in nilfs_page_mkwrite() is conditional, and if the backing device does not require stable writes, data may be modified without waiting. Fix these issues by making nilfs_page_mkwrite() wait for writeback to finish regardless of the stable write requirement of the backing device. Link: https://lkml.kernel.org/r/20240131145657.4209-1-konishi.ryusuke@gmail.com Fixes: 1d1d1a767206 ("mm: only enforce stable page writes if the backing device requires it") Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+ee2ae68da3b22d04cd8d(a)syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000047d819061004ad6c@google.com Tested-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- Please apply this patch to the stable trees indicated by the subject line prefix. These versions do not yet have page-to-folio conversion applied to the target function, so page-based "wait_on_page_writeback()" is used instead of "folio_wait_writeback()" in this patch. This did not apply as-is to v6.5 and earlier versions due to an fs-wide change. So I would like to post a separate patch for earlier stable trees. Thanks, Ryusuke Konishi fs/nilfs2/file.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c index 740ce26d1e76..0505feef79f4 100644 --- a/fs/nilfs2/file.c +++ b/fs/nilfs2/file.c @@ -105,7 +105,13 @@ static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf) nilfs_transaction_commit(inode->i_sb); mapped: - wait_for_stable_page(page); + /* + * Since checksumming including data blocks is performed to determine + * the validity of the log to be written and used for recovery, it is + * necessary to wait for writeback to finish here, regardless of the + * stable write requirement of the backing device. + */ + wait_on_page_writeback(page); out: sb_end_pagefault(inode->i_sb); return vmf_fs_error(ret); -- 2.39.3

1 year

2
1
0 0

FAILED: patch "[PATCH] powerpc/ftrace: Ignore ftrace locations in exit text sections" failed to apply to 6.7-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.7-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-6.7.y git checkout FETCH_HEAD git cherry-pick -x ea73179e64131bcd29ba6defd33732abdf8ca14b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021900-scorch-tripping-95c2@gregkh' --subject-prefix 'PATCH 6.7.y' HEAD^.. Possible dependencies: ea73179e6413 ("powerpc/ftrace: Ignore ftrace locations in exit text sections") 2ec36570c358 ("powerpc/ftrace: Fix indentation in ftrace.h") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From ea73179e64131bcd29ba6defd33732abdf8ca14b Mon Sep 17 00:00:00 2001 From: Naveen N Rao <naveen(a)kernel.org> Date: Tue, 13 Feb 2024 23:24:10 +0530 Subject: [PATCH] powerpc/ftrace: Ignore ftrace locations in exit text sections Michael reported that we are seeing an ftrace bug on bootup when KASAN is enabled and we are using -fpatchable-function-entry: ftrace: allocating 47780 entries in 18 pages ftrace-powerpc: 0xc0000000020b3d5c: No module provided for non-kernel address ------------[ ftrace bug ]------------ ftrace faulted on modifying [<c0000000020b3d5c>] 0xc0000000020b3d5c Initializing ftrace call sites ftrace record flags: 0 (0) expected tramp: c00000000008cef4 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2180 ftrace_bug+0x3c0/0x424 Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0-rc3-00120-g0f71dcfb4aef #860 Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries NIP: c0000000003aa81c LR: c0000000003aa818 CTR: 0000000000000000 REGS: c0000000033cfab0 TRAP: 0700 Not tainted (6.5.0-rc3-00120-g0f71dcfb4aef) MSR: 8000000002021033 <SF,VEC,ME,IR,DR,RI,LE> CR: 28028240 XER: 00000000 CFAR: c0000000002781a8 IRQMASK: 3 ... NIP [c0000000003aa81c] ftrace_bug+0x3c0/0x424 LR [c0000000003aa818] ftrace_bug+0x3bc/0x424 Call Trace: ftrace_bug+0x3bc/0x424 (unreliable) ftrace_process_locs+0x5f4/0x8a0 ftrace_init+0xc0/0x1d0 start_kernel+0x1d8/0x484 With CONFIG_FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY=y and CONFIG_KASAN=y, compiler emits nops in functions that it generates for registering and unregistering global variables (unlike with -pg and -mprofile-kernel where calls to _mcount() are not generated in those functions). Those functions then end up in INIT_TEXT and EXIT_TEXT respectively. We don't expect to see any profiled functions in EXIT_TEXT, so ftrace_init_nop() assumes that all addresses that aren't in the core kernel text belongs to a module. Since these functions do not match that criteria, we see the above bug. Address this by having ftrace ignore all locations in the text exit sections of vmlinux. Fixes: 0f71dcfb4aef ("powerpc/ftrace: Add support for -fpatchable-function-entry") Cc: stable(a)vger.kernel.org # v6.6+ Reported-by: Michael Ellerman <mpe(a)ellerman.id.au> Signed-off-by: Naveen N Rao <naveen(a)kernel.org> Reviewed-by: Benjamin Gray <bgray(a)linux.ibm.com> Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Link: https://msgid.link/20240213175410.1091313-1-naveen@kernel.org diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h index 1ebd2ca97f12..107fc5a48456 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -20,14 +20,6 @@ #ifndef __ASSEMBLY__ extern void _mcount(void); -static inline unsigned long ftrace_call_adjust(unsigned long addr) -{ - if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)) - addr += MCOUNT_INSN_SIZE; - - return addr; -} - unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp); @@ -142,8 +134,10 @@ static inline u8 this_cpu_get_ftrace_enabled(void) { return 1; } #ifdef CONFIG_FUNCTION_TRACER extern unsigned int ftrace_tramp_text[], ftrace_tramp_init[]; void ftrace_free_init_tramp(void); +unsigned long ftrace_call_adjust(unsigned long addr); #else static inline void ftrace_free_init_tramp(void) { } +static inline unsigned long ftrace_call_adjust(unsigned long addr) { return addr; } #endif #endif /* !__ASSEMBLY__ */ diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h index ea26665f82cf..f43f3a6b0051 100644 --- a/arch/powerpc/include/asm/sections.h +++ b/arch/powerpc/include/asm/sections.h @@ -14,6 +14,7 @@ typedef struct func_desc func_desc_t; extern char __head_end[]; extern char __srwx_boundary[]; +extern char __exittext_begin[], __exittext_end[]; /* Patch sites */ extern s32 patch__call_flush_branch_caches1; diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index 82010629cf88..d8d6b4fd9a14 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -27,10 +27,22 @@ #include <asm/ftrace.h> #include <asm/syscall.h> #include <asm/inst.h> +#include <asm/sections.h> #define NUM_FTRACE_TRAMPS 2 static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS]; +unsigned long ftrace_call_adjust(unsigned long addr) +{ + if (addr >= (unsigned long)__exittext_begin && addr < (unsigned long)__exittext_end) + return 0; + + if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)) + addr += MCOUNT_INSN_SIZE; + + return addr; +} + static ppc_inst_t ftrace_create_branch_inst(unsigned long ip, unsigned long addr, int link) { ppc_inst_t op; diff --git a/arch/powerpc/kernel/trace/ftrace_64_pg.c b/arch/powerpc/kernel/trace/ftrace_64_pg.c index 7b85c3b460a3..12fab1803bcf 100644 --- a/arch/powerpc/kernel/trace/ftrace_64_pg.c +++ b/arch/powerpc/kernel/trace/ftrace_64_pg.c @@ -37,6 +37,11 @@ #define NUM_FTRACE_TRAMPS 8 static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS]; +unsigned long ftrace_call_adjust(unsigned long addr) +{ + return addr; +} + static ppc_inst_t ftrace_call_replace(unsigned long ip, unsigned long addr, int link) { diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index 1c5970df3233..f420df7888a7 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -281,7 +281,9 @@ SECTIONS * to deal with references from __bug_table */ .exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) { + __exittext_begin = .; EXIT_TEXT + __exittext_end = .; } . = ALIGN(PAGE_SIZE);

1 year

1
0
0 0

FAILED: patch "[PATCH] powerpc/64: Set task pt_regs->link to the LR value on scv" 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 aad98efd0b121f63a2e1c221dcb4d4850128c697 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021931-venue-await-dbc3@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: aad98efd0b12 ("powerpc/64: Set task pt_regs->link to the LR value on scv entry") e754f4d13e39 ("powerpc/64: move interrupt return asm to interrupt_64.S") 59dc5bfca0cb ("powerpc/64s: avoid reloading (H)SRR registers if they are still valid") 1df7d5e4baea ("powerpc/64s: introduce different functions to return from SRR vs HSRR interrupts") ac3d085368b3 ("powerpc/signal32: Remove impossible #ifdef combinations") 69d4d6e5fd9f ("powerpc: Don't use 'struct ppc_inst' to reference instruction location") e90a21ea801d ("powerpc/lib/code-patching: Don't use struct 'ppc_inst' for runnable code in tests.") 6c0d181daabc ("powerpc/lib/code-patching: Make instr_is_branch_to_addr() static") 18c85964b10b ("powerpc: Do not dereference code as 'struct ppc_inst' (uprobe, code-patching, feature-fixups)") f30becb5e9ec ("powerpc: Replace PPC_INST_NOP by PPC_RAW_NOP()") ef909ba95414 ("powerpc/lib/feature-fixups: Use PPC_RAW_xxx() macros") 5a03e1e9728e ("powerpc/ftrace: Use PPC_RAW_MFLR() and PPC_RAW_NOP()") e73045975601 ("powerpc/security: Use PPC_RAW_BLR() and PPC_RAW_NOP()") 47b04699d070 ("powerpc/modules: Use PPC_RAW_xx() macros") 1c9debbc2eb5 ("powerpc/signal: Use PPC_RAW_xx() macros") 82123a3d1d5a ("powerpc/kprobes: Fix validation of prefixed instructions across page boundary") d72500f99284 ("powerpc/64s/syscall: Fix ptrace syscall info with scv syscalls") 5b48ba2fbd77 ("powerpc/64s: Fix stf mitigation patching w/strict RWX & hash") 49b39ec248af ("powerpc/64s: Fix entry flush patching w/strict RWX & hash") 2c8c89b95831 ("powerpc/pseries: Fix hcall tracing recursion in pv queued spinlocks") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From aad98efd0b121f63a2e1c221dcb4d4850128c697 Mon Sep 17 00:00:00 2001 From: Naveen N Rao <naveen(a)kernel.org> Date: Fri, 2 Feb 2024 21:13:16 +0530 Subject: [PATCH] powerpc/64: Set task pt_regs->link to the LR value on scv entry Nysal reported that userspace backtraces are missing in offcputime bcc tool. As an example: $ sudo ./bcc/tools/offcputime.py -uU Tracing off-CPU time (us) of user threads by user stack... Hit Ctrl-C to end. ^C write - python (9107) 8 write - sudo (9105) 9 mmap - python (9107) 16 clock_nanosleep - multipathd (697) 3001604 The offcputime bcc tool attaches a bpf program to a kprobe on finish_task_switch(), which is usually hit on a syscall from userspace. With the switch to system call vectored, we started setting pt_regs->link to zero. This is because system call vectored behaves like a function call with LR pointing to the system call return address, and with no modification to SRR0/SRR1. The LR value does indicate our next instruction, so it is being saved as pt_regs->nip, and pt_regs->link is being set to zero. This is not a problem by itself, but BPF uses perf callchain infrastructure for capturing stack traces, and that stores LR as the second entry in the stack trace. perf has code to cope with the second entry being zero, and skips over it. However, generic userspace unwinders assume that a zero entry indicates end of the stack trace, resulting in a truncated userspace stack trace. Rather than fixing all userspace unwinders to ignore/skip past the second entry, store the real LR value in pt_regs->link so that there continues to be a valid, though duplicate entry in the stack trace. With this change: $ sudo ./bcc/tools/offcputime.py -uU Tracing off-CPU time (us) of user threads by user stack... Hit Ctrl-C to end. ^C write write [unknown] [unknown] [unknown] [unknown] [unknown] PyObject_VectorcallMethod [unknown] [unknown] PyObject_CallOneArg PyFile_WriteObject PyFile_WriteString [unknown] [unknown] PyObject_Vectorcall _PyEval_EvalFrameDefault PyEval_EvalCode [unknown] [unknown] [unknown] _PyRun_SimpleFileObject _PyRun_AnyFileObject Py_RunMain [unknown] Py_BytesMain [unknown] __libc_start_main - python (1293) 7 write write [unknown] sudo_ev_loop_v1 sudo_ev_dispatch_v1 [unknown] [unknown] [unknown] [unknown] __libc_start_main - sudo (1291) 7 syscall syscall bpf_open_perf_buffer_opts [unknown] [unknown] [unknown] [unknown] _PyObject_MakeTpCall PyObject_Vectorcall _PyEval_EvalFrameDefault PyEval_EvalCode [unknown] [unknown] [unknown] _PyRun_SimpleFileObject _PyRun_AnyFileObject Py_RunMain [unknown] Py_BytesMain [unknown] __libc_start_main - python (1293) 11 clock_nanosleep clock_nanosleep nanosleep sleep [unknown] [unknown] __clone - multipathd (698) 3001661 Fixes: 7fa95f9adaee ("powerpc/64s: system call support for scv/rfscv instructions") Cc: stable(a)vger.kernel.org Reported-by: "Nysal Jan K.A" <nysal(a)linux.ibm.com> Signed-off-by: Naveen N Rao <naveen(a)kernel.org> Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Link: https://msgid.link/20240202154316.395276-1-naveen@kernel.org diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S index bd863702d812..1ad059a9e2fe 100644 --- a/arch/powerpc/kernel/interrupt_64.S +++ b/arch/powerpc/kernel/interrupt_64.S @@ -52,7 +52,8 @@ _ASM_NOKPROBE_SYMBOL(system_call_vectored_\name) mr r10,r1 ld r1,PACAKSAVE(r13) std r10,0(r1) - std r11,_NIP(r1) + std r11,_LINK(r1) + std r11,_NIP(r1) /* Saved LR is also the next instruction */ std r12,_MSR(r1) std r0,GPR0(r1) std r10,GPR1(r1) @@ -70,7 +71,6 @@ _ASM_NOKPROBE_SYMBOL(system_call_vectored_\name) std r9,GPR13(r1) SAVE_NVGPRS(r1) std r11,_XER(r1) - std r11,_LINK(r1) std r11,_CTR(r1) li r11,\trapnr

1 year

1
0
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror February 2024