From: Zheng Yejian <zhengyejian1@huawei.com>
To: <rostedt@goodmis.org>, <mingo@redhat.com>,
<linux-kernel@vger.kernel.org>
Cc: <zhengyejian1@huawei.com>
Subject: [PATCH] ftrace: Fix char print issue in print_ip_ins()
Date: Mon, 10 Oct 2022 19:15:24 +0000 [thread overview]
Message-ID: <20221010191524.1626867-1-zhengyejian1@huawei.com> (raw)
When ftrace bug happened, following log shows every byte data in
problem ip address:
actual: ffffffe8:6b:ffffffd9:01:21
However that seems a little confusing, and it is because format
'%x' being used to print signed chars in print_ip_ins().
After this patch, the log is like:
actual: e8:6b:d9:01:21
Fixes: 6c14133d2d3f ("ftrace: Do not blindly read the ip address in ftrace_bug()")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
---
kernel/trace/ftrace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 439e2ab6905e..251ba30c871d 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2015,7 +2015,7 @@ static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
static void print_ip_ins(const char *fmt, const unsigned char *p)
{
- char ins[MCOUNT_INSN_SIZE];
+ unsigned char ins[MCOUNT_INSN_SIZE];
int i;
if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) {
--
2.25.1
next reply other threads:[~2022-10-10 11:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-10 19:15 Zheng Yejian [this message]
2022-10-11 2:35 ` [PATCH] ftrace: Fix char print issue in print_ip_ins() Joe Perches
2022-10-11 11:22 ` Zheng Yejian
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