Hi Masami,
On 03/08/2018 02:20 PM, Masami Hiramatsu wrote:
> Add array type support for probe events.
> This allows user to get arraied types from memory address.
> The array type syntax is
>
> TYPE[N]
>
> Where TYPE is one of types (u8/16/32/64,s8/16/32/64,
> x8/16/32/64, symbol, string) and N is a fixed value less
> than 64.
>
> The string array type is a bit different from other types. For
> other base types, <base-type>[1] is equal to <base-type>
> (e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not
> equal to string. The string type itself represents "char array",
> but string array type represents "char * array". So, for example,
> +0(%di):string[1] is equal to +0(+0(%di)):string.
I was trying to test this patch. But I'm not getting proper data.
Here is what I'm doing...
$ cat hello.c
#include <stdio.h>
void foo1(int a[])
{
printf("%d\n", a[2]);
}
void foo(int a[])
{
printf("%d\n", a[1]);
foo1(a);
}
void main()
{
int a[3] = {4, 5, 6};
printf("%d\n", a[0]);
foo(a);
}
$ gcc -g hello.c -o hello
$ sudo ./perf probe -x ~/hello foo1 'a=a:x32[3]'
$ sudo cat /sys/kernel/debug/tracing/uprobe_events
p:probe_hello/foo1 /home/ravi/hello:0x00000000000005fc a=+96(%gpr31):x32[3]
$ sudo ./perf record -e probe_hello:foo1 ~/hello
$ sudo ./perf script
hello 6913 [038] 2857.704470: probe_hello:foo1: (100005fc) a={0xd69e4400,0x7fff,0x0}
I don't see proper values of the 'a'? Anything wrong with my perf commands :) ?
Thanks,
Ravi
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