Re: [Crash-utility] [PATCH v2 2/2] x86_64: Correct the identifier when locating the call instruction
On 2022/08/29 22:45, Tao Liu wrote:
The previous implementation to locate the call instruction is
to strstr "call", then check whether the previous char is ' '
or '\t'. The implementation is problematic. For example it
cannot resolve the following disassembly string:
"0xffffffffc06e6399 <nfs_callback_up+118>:\tcall 0xffffffff9ac8792f
<printk>"
strstr will locate the "_call" and char check fails,
as a result, extract_hex fail to get the calling address.
This patch fix the issue by strstr "\tcall" and " call", to
locate the correct call instruction.
Is it possible to add an example failure output of any command and
fixed one?
Thanks,
Kazu
>
> Signed-off-by: Tao Liu <ltao(a)redhat.com>
> ---
> v1 -> v2: No modification, sent together with patch1
> ---
> x86_64.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/x86_64.c b/x86_64.c
> index dfada48..74bd1bb 100644
> --- a/x86_64.c
> +++ b/x86_64.c
> @@ -4432,8 +4432,7 @@ x86_64_function_called_by(ulong rip)
> if (gdb_pass_through(buf, pc->tmpfile2, GNU_RETURN_ON_ERROR)) {
> rewind(pc->tmpfile2);
> while (fgets(buf, BUFSIZE, pc->tmpfile2)) {
> - if ((p1 = strstr(buf, "call")) &&
> - whitespace(*(p1-1))) {
> + if ((p1 = strstr(buf, " call")) || (p1 = strstr(buf,
"\tcall"))) {
> if (extract_hex(p1, &value, NULLCHAR, TRUE))
> break;
> }