From 65ebdeef103fd70988fdd0ffef1d4fecb0cb97ed Mon Sep 17 00:00:00 2001 From: Georgi Djakov Date: Mon, 28 Jun 2021 19:34:58 -0700 Subject: [PATCH] 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@quicinc.com Signed-off-by: Georgi Djakov Acked-by: Rafael Aquini Acked-by: David Rientjes Acked-by: Vlastimil Babka Reviewed-by: Aaron Tomlin Cc: Christoph Lameter Cc: Pekka Enberg Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slub.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 70bb844..3bc8b94 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -708,8 +708,6 @@ static void slab_bug(struct kmem_cache *s, char *fmt, ...) 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, struct page *page, 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(struct kmem_cache *s, struct page *page, 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 kmem_cache *s, struct page *page, 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); -- 2.7.4