The patch titled
Subject: mm/slub: add support for free path information of an object
has been added to the -mm tree. Its filename is
mm-slub-add-support-for-free-path-information-of-an-object.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-slub-add-support-for-free-path-information-of-an-object.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-slub-add-support-for-free-path-information-of-an-object.patch
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------------------------------------------------------
From: Maninder Singh <maninder1.s@xxxxxxxxxxx>
Subject: mm/slub: add support for free path information of an object
Add support for information of free path along with allocation path of an
object:
slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 0 size 64 allocated at meminfo_proc_show+0x40/0x4fc
[ 20.192078] meminfo_proc_show+0x40/0x4fc
[ 20.192263] seq_read_iter+0x18c/0x4c4
[ 20.192430] proc_reg_read_iter+0x84/0xac
[ 20.192617] generic_file_splice_read+0xe8/0x17c
[ 20.192816] splice_direct_to_actor+0xb8/0x290
[ 20.193008] do_splice_direct+0xa0/0xe0
[ 20.193185] do_sendfile+0x2d0/0x438
[ 20.193345] sys_sendfile64+0x12c/0x140
[ 20.193523] ret_fast_syscall+0x0/0x58
[ 20.193695] 0xbeeacde4
[ 20.193822] Free path:
[ 20.193935] meminfo_proc_show+0x5c/0x4fc
[ 20.194115] seq_read_iter+0x18c/0x4c4
[ 20.194285] proc_reg_read_iter+0x84/0xac
[ 20.194475] generic_file_splice_read+0xe8/0x17c
[ 20.194685] splice_direct_to_actor+0xb8/0x290
[ 20.194870] do_splice_direct+0xa0/0xe0
[ 20.195014] do_sendfile+0x2d0/0x438
[ 20.195174] sys_sendfile64+0x12c/0x140
[ 20.195336] ret_fast_syscall+0x0/0x58
[ 20.195491] 0xbeeacde4
Link: https://lkml.kernel.org/r/1615891032-29160-2-git-send-email-maninder1.s@xxxxxxxxxxx
Signed-off-by: Maninder Singh <maninder1.s@xxxxxxxxxxx>
Signed-off-by: Vaneet Narang <v.narang@xxxxxxxxxxx>
Co-developed-by: Vaneet Narang <v.narang@xxxxxxxxxxx>
Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Dmitry Safonov <0x7f454c46@xxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slab.h | 1 +
mm/slab_common.c | 12 +++++++++++-
mm/slub.c | 7 +++++++
mm/util.c | 2 +-
4 files changed, 20 insertions(+), 2 deletions(-)
--- a/mm/slab_common.c~mm-slub-add-support-for-free-path-information-of-an-object
+++ a/mm/slab_common.c
@@ -554,7 +554,7 @@ bool kmem_valid_obj(void *object)
* depends on the type of object and on how much debugging is enabled.
* For a slab-cache object, the fact that it is a slab object is printed,
* and, if available, the slab name, return address, and stack trace from
- * the allocation of that object.
+ * the allocation and last free path of that object.
*
* This function will splat if passed a pointer to a non-slab object.
* If you are not sure what type of object you have, you should instead
@@ -599,6 +599,16 @@ void kmem_dump_obj(void *object)
break;
pr_info(" %pS\n", kp.kp_stack[i]);
}
+
+ if (kp.kp_free_stack[0])
+ pr_cont(" Free path:\n");
+
+ for (i = 0; i < ARRAY_SIZE(kp.kp_free_stack); i++) {
+ if (!kp.kp_free_stack[i])
+ break;
+ pr_info(" %pS\n", kp.kp_free_stack[i]);
+ }
+
}
#ifndef CONFIG_SLOB
--- a/mm/slab.h~mm-slub-add-support-for-free-path-information-of-an-object
+++ a/mm/slab.h
@@ -628,6 +628,7 @@ struct kmem_obj_info {
struct kmem_cache *kp_slab_cache;
void *kp_ret;
void *kp_stack[KS_ADDRS_COUNT];
+ void *kp_free_stack[KS_ADDRS_COUNT];
};
void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page);
--- a/mm/slub.c~mm-slub-add-support-for-free-path-information-of-an-object
+++ a/mm/slub.c
@@ -4000,6 +4000,13 @@ void kmem_obj_info(struct kmem_obj_info
if (!kpp->kp_stack[i])
break;
}
+
+ trackp = get_track(s, objp, TRACK_FREE);
+ for (i = 0; i < KS_ADDRS_COUNT && i < TRACK_ADDRS_COUNT; i++) {
+ kpp->kp_free_stack[i] = (void *)trackp->addrs[i];
+ if (!kpp->kp_free_stack[i])
+ break;
+ }
#endif
#endif
}
--- a/mm/util.c~mm-slub-add-support-for-free-path-information-of-an-object
+++ a/mm/util.c
@@ -992,7 +992,7 @@ int __weak memcmp_pages(struct page *pag
* depends on the type of object and on how much debugging is enabled.
* For example, for a slab-cache object, the slab name is printed, and,
* if available, the return address and stack trace from the allocation
- * of that object.
+ * and last free path of that object.
*/
void mem_dump_obj(void *object)
{
_
Patches currently in -mm which might be from maninder1.s@xxxxxxxxxxx are
mm-slub-fixing-backtrace-of-objects-because-of-redzone-adjustment.patch
mm-slub-add-support-for-free-path-information-of-an-object.patch
arm-print-alloc-free-paths-for-address-in-registers.patch
