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mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc()

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Beginning at commit d52d3997f8 ("ipv6: Create percpu rt6_info"), the
following INFO splat is logged:

  ===============================
  [ INFO: suspicious RCU usage. ]
  4.1.0-rc7-next-20150612 #1 Not tainted
  -------------------------------
  kernel/sched/core.c:7318 Illegal context switch in RCU-bh read-side critical section!
  other info that might help us debug this:
  rcu_scheduler_active = 1, debug_locks = 0
   3 locks held by systemd/1:
   #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff815f0c8f>] rtnetlink_rcv+0x1f/0x40
   #1:  (rcu_read_lock_bh){......}, at: [<ffffffff816a34e2>] ipv6_add_addr+0x62/0x540
   #2:  (addrconf_hash_lock){+...+.}, at: [<ffffffff816a3604>] ipv6_add_addr+0x184/0x540
  stack backtrace:
  CPU: 0 PID: 1 Comm: systemd Not tainted 4.1.0-rc7-next-20150612 #1
  Hardware name: TOSHIBA TECRA A50-A/TECRA A50-A, BIOS Version 4.20   04/17/2014
  Call Trace:
    dump_stack+0x4c/0x6e
    lockdep_rcu_suspicious+0xe7/0x120
    ___might_sleep+0x1d5/0x1f0
    __might_sleep+0x4d/0x90
    kmem_cache_alloc+0x47/0x250
    create_object+0x39/0x2e0
    kmemleak_alloc_percpu+0x61/0xe0
    pcpu_alloc+0x370/0x630

Additional backtrace lines are truncated.  In addition, the above splat
is followed by several "BUG: sleeping function called from invalid
context at mm/slub.c:1268" outputs.  As suggested by Martin KaFai Lau,
these are the clue to the fix.  Routine kmemleak_alloc_percpu() always
uses GFP_KERNEL for its allocations, whereas it should follow the gfp
from its callers.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: <stable@vger.kernel.org>	[3.18+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Larry Finger 2015-06-24 16:58:51 -07:00 committed by Linus Torvalds
parent 0867a57c4f
commit 8a8c35fadf
3 changed files with 10 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
include/linux/kmemleak.h
View File

@ -28,7 +28,8 @@
extern void kmemleak_init(void) __ref;
extern void kmemleak_alloc(const void *ptr, size_t size, int min_count,
gfp_t gfp) __ref;
extern void kmemleak_alloc_percpu(const void __percpu *ptr, size_t size) __ref;
extern void kmemleak_alloc_percpu(const void __percpu *ptr, size_t size,
gfp_t gfp) __ref;
extern void kmemleak_free(const void *ptr) __ref;
extern void kmemleak_free_part(const void *ptr, size_t size) __ref;
extern void kmemleak_free_percpu(const void __percpu *ptr) __ref;
@ -71,7 +72,8 @@ static inline void kmemleak_alloc_recursive(const void *ptr, size_t size,
gfp_t gfp)
{
}
static inline void kmemleak_alloc_percpu(const void __percpu *ptr, size_t size)
static inline void kmemleak_alloc_percpu(const void __percpu *ptr, size_t size,
gfp_t gfp)
{
}
static inline void kmemleak_free(const void *ptr)

9
mm/kmemleak.c
View File

@ -930,12 +930,13 @@ EXPORT_SYMBOL_GPL(kmemleak_alloc);
* kmemleak_alloc_percpu - register a newly allocated __percpu object
* @ptr: __percpu pointer to beginning of the object
* @size: size of the object
* @gfp: flags used for kmemleak internal memory allocations
*
* This function is called from the kernel percpu allocator when a new object
* (memory block) is allocated (alloc_percpu). It assumes GFP_KERNEL
* allocation.
* (memory block) is allocated (alloc_percpu).
*/
void __ref kmemleak_alloc_percpu(const void __percpu *ptr, size_t size)
void __ref kmemleak_alloc_percpu(const void __percpu *ptr, size_t size,
gfp_t gfp)
{
unsigned int cpu;
@ -948,7 +949,7 @@ void __ref kmemleak_alloc_percpu(const void __percpu *ptr, size_t size)
if (kmemleak_enabled && ptr && !IS_ERR(ptr))
for_each_possible_cpu(cpu)
create_object((unsigned long)per_cpu_ptr(ptr, cpu),
size, 0, GFP_KERNEL);
size, 0, gfp);
else if (kmemleak_early_log)
log_early(KMEMLEAK_ALLOC_PERCPU, ptr, size, 0);
}

2
mm/percpu.c
View File

@ -1030,7 +1030,7 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved,
memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
ptr = __addr_to_pcpu_ptr(chunk->base_addr + off);
kmemleak_alloc_percpu(ptr, size);
kmemleak_alloc_percpu(ptr, size, gfp);
return ptr;
fail_unlock: