From: "Paul E. McKenney" <paulmck@kernel.org> To: Maninder Singh <maninder1.s@samsung.com> Cc: linux@armlinux.org.uk, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, vbabka@suse.cz, 0x7f454c46@gmail.com, viro@zeniv.linux.org.uk, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, a.sahrawat@samsung.com, Vaneet Narang <v.narang@samsung.com> Subject: Re: [PATCH 1/3] mm/slub: fixing backtrace of objects because of redzone adjustment Date: Tue, 16 Mar 2021 10:44:31 -0700 [thread overview] Message-ID: <20210316174431.GX2696@paulmck-ThinkPad-P72> (raw) In-Reply-To: <1615891032-29160-1-git-send-email-maninder1.s@samsung.com> On Tue, Mar 16, 2021 at 04:07:10PM +0530, Maninder Singh wrote: > fixing commit 8e7f37f2aaa5 ("mm: Add mem_dump_obj() to print source > of memory block") > > with current code, Backtrace of allocated object is coming wrong: > / # cat /proc/meminfo > [ 14.969843] slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 0 size 64 allocated at 0x6b6b6b6b > [ 14.970635] 0x6b6b6b6b > [ 14.970794] 0x6b6b6b6b > [ 14.970932] 0x6b6b6b6b > [ 14.971077] 0x6b6b6b6b > [ 14.971202] 0x6b6b6b6b > [ 14.971317] 0x6b6b6b6b > [ 14.971423] 0x6b6b6b6b > [ 14.971635] 0x6b6b6b6b > [ 14.971740] 0x6b6b6b6b > [ 14.971871] 0x6b6b6b6b > [ 14.972229] 0x6b6b6b6b > [ 14.972363] 0x6b6b6b6b > [ 14.972505] 0xa56b6b6b > [ 14.972631] 0xbbbbbbbb > [ 14.972734] 0xc8ab0400 > [ 14.972891] meminfo_proc_show+0x40/0x4fc > > And reason is red zone was not adjusted from object address. > after adding fixup for redzone, backtrace is coming correct: > / # cat /proc/meminfo > [ 14.870782] slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 128 size 64 allocated at meminfo_proc_show+0x40/0x4f4 > [ 14.871817] meminfo_proc_show+0x40/0x4f4 > [ 14.872035] seq_read_iter+0x18c/0x4c4 > [ 14.872229] proc_reg_read_iter+0x84/0xac > [ 14.872433] generic_file_splice_read+0xe8/0x17c > [ 14.872621] splice_direct_to_actor+0xb8/0x290 > [ 14.872747] do_splice_direct+0xa0/0xe0 > [ 14.872896] do_sendfile+0x2d0/0x438 > [ 14.873044] sys_sendfile64+0x12c/0x140 > [ 14.873229] ret_fast_syscall+0x0/0x58 > [ 14.873372] 0xbe861de4 > > Signed-off-by: Vaneet Narang <v.narang@samsung.com> > Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Good catch, thank you! For the series: Acked-by: Paul E. McKenney <paulmck@kernel.org> On the other hand, if you would like me to take these, we need to get a maintainer ack. Thanx, Paul > --- > mm/slub.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/slub.c b/mm/slub.c > index 1912c4614248..9d13f0117ae6 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -4052,6 +4052,7 @@ void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page) > !(s->flags & SLAB_STORE_USER)) > return; > #ifdef CONFIG_SLUB_DEBUG > + objp = fixup_red_left(s, objp); > trackp = get_track(s, objp, TRACK_ALLOC); > kpp->kp_ret = (void *)trackp->addr; > #ifdef CONFIG_STACKTRACE > -- > 2.17.1 >
WARNING: multiple messages have this Message-ID (diff)
From: "Paul E. McKenney" <paulmck@kernel.org> To: Maninder Singh <maninder1.s@samsung.com> Cc: linux@armlinux.org.uk, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, vbabka@suse.cz, 0x7f454c46@gmail.com, viro@zeniv.linux.org.uk, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, a.sahrawat@samsung.com, Vaneet Narang <v.narang@samsung.com> Subject: Re: [PATCH 1/3] mm/slub: fixing backtrace of objects because of redzone adjustment Date: Tue, 16 Mar 2021 10:44:31 -0700 [thread overview] Message-ID: <20210316174431.GX2696@paulmck-ThinkPad-P72> (raw) In-Reply-To: <1615891032-29160-1-git-send-email-maninder1.s@samsung.com> On Tue, Mar 16, 2021 at 04:07:10PM +0530, Maninder Singh wrote: > fixing commit 8e7f37f2aaa5 ("mm: Add mem_dump_obj() to print source > of memory block") > > with current code, Backtrace of allocated object is coming wrong: > / # cat /proc/meminfo > [ 14.969843] slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 0 size 64 allocated at 0x6b6b6b6b > [ 14.970635] 0x6b6b6b6b > [ 14.970794] 0x6b6b6b6b > [ 14.970932] 0x6b6b6b6b > [ 14.971077] 0x6b6b6b6b > [ 14.971202] 0x6b6b6b6b > [ 14.971317] 0x6b6b6b6b > [ 14.971423] 0x6b6b6b6b > [ 14.971635] 0x6b6b6b6b > [ 14.971740] 0x6b6b6b6b > [ 14.971871] 0x6b6b6b6b > [ 14.972229] 0x6b6b6b6b > [ 14.972363] 0x6b6b6b6b > [ 14.972505] 0xa56b6b6b > [ 14.972631] 0xbbbbbbbb > [ 14.972734] 0xc8ab0400 > [ 14.972891] meminfo_proc_show+0x40/0x4fc > > And reason is red zone was not adjusted from object address. > after adding fixup for redzone, backtrace is coming correct: > / # cat /proc/meminfo > [ 14.870782] slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 128 size 64 allocated at meminfo_proc_show+0x40/0x4f4 > [ 14.871817] meminfo_proc_show+0x40/0x4f4 > [ 14.872035] seq_read_iter+0x18c/0x4c4 > [ 14.872229] proc_reg_read_iter+0x84/0xac > [ 14.872433] generic_file_splice_read+0xe8/0x17c > [ 14.872621] splice_direct_to_actor+0xb8/0x290 > [ 14.872747] do_splice_direct+0xa0/0xe0 > [ 14.872896] do_sendfile+0x2d0/0x438 > [ 14.873044] sys_sendfile64+0x12c/0x140 > [ 14.873229] ret_fast_syscall+0x0/0x58 > [ 14.873372] 0xbe861de4 > > Signed-off-by: Vaneet Narang <v.narang@samsung.com> > Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Good catch, thank you! For the series: Acked-by: Paul E. McKenney <paulmck@kernel.org> On the other hand, if you would like me to take these, we need to get a maintainer ack. Thanx, Paul > --- > mm/slub.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/slub.c b/mm/slub.c > index 1912c4614248..9d13f0117ae6 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -4052,6 +4052,7 @@ void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page) > !(s->flags & SLAB_STORE_USER)) > return; > #ifdef CONFIG_SLUB_DEBUG > + objp = fixup_red_left(s, objp); > trackp = get_track(s, objp, TRACK_ALLOC); > kpp->kp_ret = (void *)trackp->addr; > #ifdef CONFIG_STACKTRACE > -- > 2.17.1 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-03-16 17:45 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <CGME20210316103723epcas5p1f750d5cfe029fa69aea8d88f0bd408f3@epcas5p1.samsung.com> 2021-03-16 10:37 ` [PATCH 1/3] mm/slub: fixing backtrace of objects because of redzone adjustment Maninder Singh 2021-03-16 10:37 ` Maninder Singh [not found] ` <CGME20210316103736epcas5p3758de57b57c732074acc0989e563cc2e@epcas5p3.samsung.com> 2021-03-16 10:37 ` [PATCH 2/3] mm/slub: Add Support for free path information of an object Maninder Singh 2021-03-16 10:37 ` Maninder Singh 2021-03-18 12:35 ` Vlastimil Babka 2021-03-18 12:35 ` Vlastimil Babka 2021-03-19 23:23 ` Paul E. McKenney 2021-03-19 23:23 ` Paul E. McKenney [not found] ` <CGME20210316103745epcas5p3994f29958b7f14aec8cbd90fa518761f@epcas5p3.samsung.com> 2021-03-16 10:37 ` [PATCH 3/3] arm: print alloc free paths for address in registers Maninder Singh 2021-03-16 10:37 ` Maninder Singh 2021-03-16 17:44 ` Paul E. McKenney [this message] 2021-03-16 17:44 ` [PATCH 1/3] mm/slub: fixing backtrace of objects because of redzone adjustment Paul E. McKenney 2021-03-18 12:33 ` Vlastimil Babka 2021-03-18 12:33 ` Vlastimil Babka
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