Re: [PATCH] ftrace: Fix print_ip_ins() to print only two digits per byte

[Zheng Yejian]

On 2022/12/9 23:56, Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
>
> Fix print_ip_ins() to use unsigned char, as:
>
> 	e9:2b:b6:0d:18
>
> is easier to understand than
>
> 	ffffffe9:2b:ffffffb6:0d:18
>
> Link: https://lore.kernel.org/all/CA+wXwBQ-VhK+hpBtYtyZP-NiX4g8fqRRWithFOHQW-0coQ3vLg@xxxxxxxxxxxxxx/
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 6c14133d2d3f7 ("ftrace: Do not blindly read the ip address in ftrace_bug()")
> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
> ---
>   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 d04552c0c275..32fc1600d596 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -2028,7 +2028,7 @@ 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];
>   
>   	if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) {
>   		printk(KERN_CONT "%s[FAULT] %px\n", fmt, p);

Hi, Steve,

commit 30f7d1cac2aa ("ftrace: Fix char print issue in print_ip_ins()")
has solved this issue.

Link: 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=30f7d1cac2aab8fec560a388ad31ca5e5d04a822