2020-07-29 11:33:35

by Zhaoyang Huang

[permalink] [raw]
Subject: [PATCH] trace : use kvmalloc instead of kmalloc

High order memory stuff within trace could introduce OOM, use kvmalloc instead.

traced_probes invoked oom-killer: gfp_mask=0x140c0c0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null), order=2, oom_score_adj=-1

traced_probes cpuset=system-background mems_allowed=0
CPU: 3 PID: 588 Comm: traced_probes Tainted: G W O 4.14.181 #1
Hardware name: Generic DT based system
(unwind_backtrace) from [<c010d824>] (show_stack+0x20/0x24)
(show_stack) from [<c0b2e174>] (dump_stack+0xa8/0xec)
(dump_stack) from [<c027d584>] (dump_header+0x9c/0x220)
(dump_header) from [<c027cfe4>] (oom_kill_process+0xc0/0x5c4)
(oom_kill_process) from [<c027cb94>] (out_of_memory+0x220/0x310)
(out_of_memory) from [<c02816bc>] (__alloc_pages_nodemask+0xff8/0x13a4)
(__alloc_pages_nodemask) from [<c02a6a1c>] (kmalloc_order+0x30/0x48)
(kmalloc_order) from [<c02a6a64>] (kmalloc_order_trace+0x30/0x118)
(kmalloc_order_trace) from [<c0223d7c>] (tracing_buffers_open+0x50/0xfc)
(tracing_buffers_open) from [<c02e6f58>] (do_dentry_open+0x278/0x34c)
(do_dentry_open) from [<c02e70d0>] (vfs_open+0x50/0x70)
(vfs_open) from [<c02f7c24>] (path_openat+0x5fc/0x169c)
(path_openat) from [<c02f75c4>] (do_filp_open+0x94/0xf8)
(do_filp_open) from [<c02e7650>] (do_sys_open+0x168/0x26c)
(do_sys_open) from [<c02e77bc>] (SyS_openat+0x34/0x38)
(SyS_openat) from [<c0108bc0>] (ret_fast_syscall+0x0/0x28)

Signed-off-by: Zhaoyang Huang <[email protected]>
---
kernel/trace/trace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ca1ee65..d4eb7ea 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6891,7 +6891,7 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp)
if (trace_array_get(tr) < 0)
return -ENODEV;

- info = kzalloc(sizeof(*info), GFP_KERNEL);
+ info = kvmalloc(sizeof(*info), GFP_KERNEL);
if (!info) {
trace_array_put(tr);
return -ENOMEM;
--
1.9.1