The patch titled Subject: mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc() has been added to the -mm tree. Its filename is mm-kmemleak_alloc_percpu-should-follow-the-gfp-from-per_alloc.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-kmemleak_alloc_percpu-should-follow-the-gfp-from-per_alloc.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-kmemleak_alloc_percpu-should-follow-the-gfp-from-per_alloc.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Larry Finger <Larry.Finger@xxxxxxxxxxxx> Subject: mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc() 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 0000000000000001 ffff880224e07838 ffffffff817263a4 ffffffff810ccf2a ffff880224e08000 ffff880224e07868 ffffffff810b6827 0000000000000000 ffffffff81a445d3 00000000000004f4 ffff88022682e100 ffff880224e07898 Call Trace: [<ffffffff817263a4>] dump_stack+0x4c/0x6e [<ffffffff810ccf2a>] ? console_unlock+0x1ca/0x510 [<ffffffff810b6827>] lockdep_rcu_suspicious+0xe7/0x120 [<ffffffff8108cf05>] ___might_sleep+0x1d5/0x1f0 [<ffffffff8108cf6d>] __might_sleep+0x4d/0x90 [<ffffffff811f3789>] ? create_object+0x39/0x2e0 [<ffffffff811da427>] kmem_cache_alloc+0x47/0x250 [<ffffffff813c19ae>] ? find_next_zero_bit+0x1e/0x20 [<ffffffff811f3789>] create_object+0x39/0x2e0 [<ffffffff810b7eb6>] ? mark_held_locks+0x66/0x90 [<ffffffff8172efab>] ? _raw_spin_unlock_irqrestore+0x4b/0x60 [<ffffffff817193c1>] kmemleak_alloc_percpu+0x61/0xe0 [<ffffffff811a26f0>] 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@xxxxxxx> Reviewed-by: Kamalesh Babulal <kamalesh@xxxxxxxxxxxxxxxxxx> Acked-by: Martin KaFai Lau <kafai@xxxxxx> Signed-off-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx> Cc: Martin KaFai Lau <kafai@xxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [3.18+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/kmemleak.h | 6 ++++-- mm/kmemleak.c | 9 +++++---- mm/percpu.c | 2 +- 3 files changed, 10 insertions(+), 7 deletions(-) diff -puN include/linux/kmemleak.h~mm-kmemleak_alloc_percpu-should-follow-the-gfp-from-per_alloc include/linux/kmemleak.h --- a/include/linux/kmemleak.h~mm-kmemleak_alloc_percpu-should-follow-the-gfp-from-per_alloc +++ a/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) diff -puN mm/kmemleak.c~mm-kmemleak_alloc_percpu-should-follow-the-gfp-from-per_alloc mm/kmemleak.c --- a/mm/kmemleak.c~mm-kmemleak_alloc_percpu-should-follow-the-gfp-from-per_alloc +++ a/mm/kmemleak.c @@ -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 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); } diff -puN mm/percpu.c~mm-kmemleak_alloc_percpu-should-follow-the-gfp-from-per_alloc mm/percpu.c --- a/mm/percpu.c~mm-kmemleak_alloc_percpu-should-follow-the-gfp-from-per_alloc +++ a/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: _ Patches currently in -mm which might be from Larry.Finger@xxxxxxxxxxxx are mm-kmemleak_alloc_percpu-should-follow-the-gfp-from-per_alloc.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html