Messages in this thread Patch in this message | | | Subject | Re: [LKP] [vfree, kvfree] a79ed8bfb2: BUG:sleeping_function_called_from_invalid_context_at_mm/util.c | From | Andrey Ryabinin <> | Date | Tue, 18 Sep 2018 12:43:31 +0300 |
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On 09/18/2018 11:52 AM, kernel test robot wrote:
> > [ 3.265372] BUG: sleeping function called from invalid context at mm/util.c:449 > [ 3.288552] in_atomic(): 0, irqs_disabled(): 0, pid: 142, name: rhashtable_thra > [ 3.301548] INFO: lockdep is turned off. > [ 3.302214] Preemption disabled at: > [ 3.302221] [<c163e86f>] get_random_u32+0x4f/0x100 > [ 3.327556] CPU: 0 PID: 142 Comm: rhashtable_thra Tainted: G W T 4.19.0-rc3-00266-ga79ed8bf #656 > [ 3.328540] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 > [ 3.328540] Call Trace: > [ 3.328540] ? dump_stack+0x55/0x7b > [ 3.328540] ? get_random_u32+0x4f/0x100 > [ 3.328540] ? ___might_sleep+0x11d/0x170 > [ 3.328540] ? kvfree+0x61/0x70 > [ 3.328540] ? bucket_table_free+0x18/0x80 > [ 3.328540] ? bucket_table_alloc+0x79/0x160 > [ 3.328540] ? rhashtable_insert_slow+0x25d/0x2d0 > [ 3.328540] ? insert_retry+0x1df/0x320 > [ 3.328540] ? threadfunc+0xa3/0x3fe > [ 3.328540] ? kzalloc+0x14/0x14 > [ 3.328540] ? _raw_spin_unlock_irqrestore+0x30/0x50 > [ 3.328540] ? kthread+0xd1/0x100 > [ 3.328540] ? insert_retry+0x320/0x320 > [ 3.328540] ? kthread_delayed_work_timer_fn+0x80/0x80 > [ 3.328540] ? ret_from_fork+0x2e/0x38
Seems like we need to drop might_sleep_if() from kvfree().
rcu_read_lock() rhashtable_insert_rehash() new_tbl = bucket_table_alloc(ht, size, GFP_ATOMIC | __GFP_NOWARN); ->kvmalloc();
bucket_table_free(new_tbl); ->kvfree() rcu_read_unlock()
kvmalloc(..., GFP_ATOMIC) simply always kmalloc: if ((flags & GFP_KERNEL) != GFP_KERNEL) return kmalloc_node(size, flags, node);
So in the above case, kvfree() always frees kmalloced memory -> and never calls vfree().
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> --- mm/util.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/mm/util.c b/mm/util.c index 929ed1795bc1..7f1f165f46af 100644 --- a/mm/util.c +++ b/mm/util.c @@ -446,8 +446,6 @@ EXPORT_SYMBOL(kvmalloc_node); */ void kvfree(const void *addr) { - might_sleep_if(!in_interrupt()); - if (is_vmalloc_addr(addr)) vfree(addr); else --
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