| From 8a8c35fadfaf55629a37ef1a8ead1b8fb32581d2 Mon Sep 17 00:00:00 2001 |
| From: Larry Finger <Larry.Finger@lwfinger.net> |
| Date: Wed, 24 Jun 2015 16:58:51 -0700 |
| Subject: mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc() |
| |
| From: Larry Finger <Larry.Finger@lwfinger.net> |
| |
| commit 8a8c35fadfaf55629a37ef1a8ead1b8fb32581d2 upstream. |
| |
| Beginning at commit d52d3997f843 ("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> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| include/linux/kmemleak.h | 6 ++++-- |
| mm/kmemleak.c | 9 +++++---- |
| mm/percpu.c | 2 +- |
| 3 files changed, 10 insertions(+), 7 deletions(-) |
| |
| --- a/include/linux/kmemleak.h |
| +++ b/include/linux/kmemleak.h |
| @@ -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_recurs |
| 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) |
| --- a/mm/kmemleak.c |
| +++ b/mm/kmemleak.c |
| @@ -909,12 +909,13 @@ 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; |
| |
| @@ -927,7 +928,7 @@ void __ref kmemleak_alloc_percpu(const v |
| 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); |
| } |
| --- a/mm/percpu.c |
| +++ b/mm/percpu.c |
| @@ -1030,7 +1030,7 @@ area_found: |
| 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: |