The following commit has been merged into the core/rcu branch of tip:
Commit-ID: e548eaa116d858f07816d41e24835a41f7e7d270
Gitweb: https://git.kernel.org/tip/e548eaa116d858f07816d41e24835a41f7e7d270
Author: Maninder Singh <maninder1.s@xxxxxxxxxxx>
AuthorDate: Tue, 16 Mar 2021 16:07:11 +05:30
Committer: Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Mon, 10 May 2021 16:01:41 -07:00
mm/slub: Add Support for free path information of an object
This commit adds enables a stack dump for the last free 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
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Co-developed-by: Vaneet Narang <v.narang@xxxxxxxxxxx>
Signed-off-by: Vaneet Narang <v.narang@xxxxxxxxxxx>
Signed-off-by: Maninder Singh <maninder1.s@xxxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
mm/slab.h | 1 +
mm/slab_common.c | 12 +++++++++++-
mm/slub.c | 7 +++++++
mm/util.c | 2 +-
4 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/mm/slab.h b/mm/slab.h
index 18c1927..7189daa 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -640,6 +640,7 @@ 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);
#endif
diff --git a/mm/slab_common.c b/mm/slab_common.c
index f8833d3..92e3aa7 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -564,7 +564,7 @@ EXPORT_SYMBOL_GPL(kmem_valid_obj);
* 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
@@ -609,6 +609,16 @@ 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]);
+ }
+
}
EXPORT_SYMBOL_GPL(kmem_dump_obj);
#endif
diff --git a/mm/slub.c b/mm/slub.c
index 8f2d135..deec894 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4011,6 +4011,13 @@ void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page)
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
}
diff --git a/mm/util.c b/mm/util.c
index a8bf17f..0b6dd9d 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -983,7 +983,7 @@ int __weak memcmp_pages(struct page *page1, struct page *page2)
* 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)
{
|