Patch "perf/core: Bail out early if the request AUX area is out of bound" has been added to the 6.5-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    perf/core: Bail out early if the request AUX area is out of bound

to the 6.5-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     perf-core-bail-out-early-if-the-request-aux-area-is-.patch
and it can be found in the queue-6.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit d5eb40bf0355201f5b7583891bb99575d2b8b08c
Author: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
Date:   Thu Sep 7 08:43:07 2023 +0800

    perf/core: Bail out early if the request AUX area is out of bound
    
    [ Upstream commit 54aee5f15b83437f23b2b2469bcf21bdd9823916 ]
    
    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@xxxxxxxxxxxxxxxxx>
    Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
    Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index a0433f37b0243..4a260ceed9c73 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -699,6 +699,12 @@ 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)



[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux