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authorShuai Xue <xueshuai@linux.alibaba.com>2023-09-07 08:43:07 +0800
committerIngo Molnar <mingo@kernel.org>2023-09-12 17:46:31 +0200
commit54aee5f15b83437f23b2b2469bcf21bdd9823916 (patch)
treeaa67bb2063f7f936451316095356012833ce0174 /kernel/events
parentffbe4ab0beda55b5c467aa3d95ca14db75a84717 (diff)
perf/core: Bail out early if the request AUX area is out of bound
When perf-record with a large AUX area, e.g 4GB, it fails with: #perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1 failed to mmap with 12 (Cannot allocate memory) and it reveals a WARNING with __alloc_pages(): ------------[ cut here ]------------ WARNING: CPU: 44 PID: 17573 at mm/page_alloc.c:5568 __alloc_pages+0x1ec/0x248 Call trace: __alloc_pages+0x1ec/0x248 __kmalloc_large_node+0xc0/0x1f8 __kmalloc_node+0x134/0x1e8 rb_alloc_aux+0xe0/0x298 perf_mmap+0x440/0x660 mmap_region+0x308/0x8a8 do_mmap+0x3c0/0x528 vm_mmap_pgoff+0xf4/0x1b8 ksys_mmap_pgoff+0x18c/0x218 __arm64_sys_mmap+0x38/0x58 invoke_syscall+0x50/0x128 el0_svc_common.constprop.0+0x58/0x188 do_el0_svc+0x34/0x50 el0_svc+0x34/0x108 el0t_64_sync_handler+0xb8/0xc0 el0t_64_sync+0x1a4/0x1a8 'rb->aux_pages' allocated by kcalloc() is a pointer array which is used to maintains AUX trace pages. The allocated page for this array is physically contiguous (and virtually contiguous) with an order of 0..MAX_ORDER. If the size of pointer array crosses the limitation set by MAX_ORDER, it reveals a WARNING. So bail out early with -ENOMEM if the request AUX area is out of bound, e.g.: #perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1 failed to mmap with 12 (Cannot allocate memory) Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/ring_buffer.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index fb1e180b5f0a..e8d82c2f07d0 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -700,6 +700,12 @@ int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
watermark = 0;
}
+ /*
+ * kcalloc_node() is unable to allocate buffer if the size is larger
+ * than: PAGE_SIZE << MAX_ORDER; directly bail out in this case.
+ */
+ if (get_order((unsigned long)nr_pages * sizeof(void *)) > MAX_ORDER)
+ return -ENOMEM;
rb->aux_pages = kcalloc_node(nr_pages, sizeof(void *), GFP_KERNEL,
node);
if (!rb->aux_pages)