From: Gil Fruchter <gilf@ezchip.com>
To: <rostedt@goodmis.org>, <mingo@redhat.com>
Cc: <linux-kernel@vger.kernel.org>, <giladb@ezchip.com>,
<cmetcalf@ezchip.com>, <noamc@ezchip.com>,
Gil Fruchter <gilf@ezchip.com>
Subject: [PATCH v2 2/2] tracing: Fix for non-continuous cpu ids
Date: Tue, 9 Jun 2015 10:32:35 +0300 [thread overview]
Message-ID: <1433835155-6894-3-git-send-email-gilf@ezchip.com> (raw)
In-Reply-To: <1433251589-21013-1-git-send-email-gilf@ezchip.com>
Currently exception occures due to access beyond buffer_iter
range while using index of cpu bigger than num_possible_cpus().
Below there is an example for such exception when we use
cpus 0,1,16,17.
In order to fix buffer allocation size for non-continuous cpu ids
we allocate according to the max cpu id and not according to the
amount of possible cpus.
Example:
$ cat /sys/kernel/debug/tracing/per_cpu/cpu1/trace
Path: /bin/busybox
CPU: 0 PID: 82 Comm: cat Not tainted 4.0.0 #29
task: 80734c80 ti: 80012000 task.ti: 80012000
[ECR ]: 0x00220100 => Invalid Read @ 0x00000000 by insn @ 0x800abafc
[EFA ]: 0x00000000
[BLINK ]: ring_buffer_read_finish+0x24/0x64
[ERET ]: rb_check_pages+0x20/0x188
[STAT32]: 0x00001a00 :
BTA: 0x800abafc SP: 0x80013f0c FP: 0x57719cf8
LPS: 0x200036b4 LPE: 0x200036b8 LPC: 0x00000000
r00: 0x8002aca0 r01: 0x00001606 r02: 0x00000000
r03: 0x00000001 r04: 0x00000000 r05: 0x804b4954
r06: 0x00030003 r07: 0x8002a260 r08: 0x00000286
r09: 0x00080002 r10: 0x00001006 r11: 0x807351a4
r12: 0x00000001
Stack Trace:
rb_check_pages+0x20/0x188
ring_buffer_read_finish+0x24/0x64
tracing_release+0x4e/0x170
__fput+0x62/0x158
task_work_run+0xa2/0xd4
do_notify_resume+0x52/0x7c
resume_user_mode_begin+0xdc/0xe0
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Gil Fruchter <gilf@ezchip.com>
---
kernel/trace/trace.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 57ffc4a..8c5b382 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3034,7 +3034,7 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
if (!iter)
return ERR_PTR(-ENOMEM);
- iter->buffer_iter = kcalloc(num_possible_cpus(), sizeof(*iter->buffer_iter),
+ iter->buffer_iter = kcalloc(nr_cpu_ids, sizeof(*iter->buffer_iter),
GFP_KERNEL);
if (!iter->buffer_iter)
goto release;
--
1.7.1
next prev parent reply other threads:[~2015-06-09 7:34 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-02 13:26 [PATCH 0/2] Fix tracing with non-continuous cpu ids Gil Fruchter
2015-06-02 13:26 ` [PATCH 1/2] tracing: Prefer kcalloc over kzalloc with multiply Gil Fruchter
2015-06-02 14:15 ` Steven Rostedt
2015-06-03 11:53 ` Gil Fruchter
2015-06-08 15:21 ` Steven Rostedt
2015-06-02 13:26 ` [PATCH 2/2] tracing: Fix for non-continuous cpu ids Gil Fruchter
2015-06-02 14:26 ` Steven Rostedt
2015-06-02 15:47 ` Gilad Ben-Yossef
2015-06-09 7:32 ` [PATCH v2 0/2] Fix tracing with " Gil Fruchter
2015-06-09 7:32 ` [PATCH v2 1/2] tracing: Prefer kcalloc over kzalloc with multiply Gil Fruchter
2015-06-09 7:32 ` Gil Fruchter [this message]
2015-07-13 16:12 ` [PATCH v2 2/2] tracing: Fix for non-continuous cpu ids Steven Rostedt
2015-07-14 10:12 ` Gil Fruchter
2015-07-14 13:22 ` Steven Rostedt
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