The patch titled
Subject: mm/slub: add taint after the errors are printed
has been added to the -mm tree. Its filename is
mm-slub-add-taint-after-the-errors-are-printed.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-slub-add-taint-after-the-errors-are-printed.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-slub-add-taint-after-the-errors-are-printed.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Georgi Djakov <quic_c_gdjako@xxxxxxxxxxx>
Subject: mm/slub: add taint after the errors are printed
When running the kernel with panic_on_taint, the usual slub debug error
messages are not being printed when object corruption happens. That's
because we panic in add_taint(), which is called before printing the
additional information. This is a bit unfortunate as the error messages
are actually very useful, especially before a panic. Let's fix this by
moving add_taint() after the errors are printed on the console.
Link: https://lkml.kernel.org/r/1623860738-146761-1-git-send-email-quic_c_gdjako@xxxxxxxxxxx
Signed-off-by: Georgi Djakov <quic_c_gdjako@xxxxxxxxxxx>
Acked-by: Rafael Aquini <aquini@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slub.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/mm/slub.c~mm-slub-add-taint-after-the-errors-are-printed
+++ a/mm/slub.c
@@ -708,8 +708,6 @@ static void slab_bug(struct kmem_cache *
pr_err("=============================================================================\n");
pr_err("BUG %s (%s): %pV\n", s->name, print_tainted(), &vaf);
pr_err("-----------------------------------------------------------------------------\n\n");
-
- add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
va_end(args);
}
@@ -790,6 +788,7 @@ void object_err(struct kmem_cache *s, st
slab_bug(s, "%s", reason);
print_trailer(s, page, object);
+ add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
}
static __printf(3, 4) void slab_err(struct kmem_cache *s, struct page *page,
@@ -807,6 +806,7 @@ static __printf(3, 4) void slab_err(stru
slab_bug(s, "%s", buf);
print_page_info(page);
dump_stack();
+ add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
}
static void init_object(struct kmem_cache *s, void *object, u8 val)
@@ -858,6 +858,7 @@ static int check_bytes_and_report(struct
fault, end - 1, fault - addr,
fault[0], value);
print_trailer(s, page, object);
+ add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
skip_bug_print:
restore_bytes(s, what, value, fault, end);
_
Patches currently in -mm which might be from quic_c_gdjako@xxxxxxxxxxx are
mm-slub-add-taint-after-the-errors-are-printed.patch
