From: Arnaldo Carvalho de Melo on
Em Thu, Jul 22, 2010 at 10:20:44AM +0300, Gleb Natapov escreveu:
> strtoull() returns valid number when it gets line with label and following
> test passes too. I can't think of a way to unambiguously distinguish between
> label and valid rip. May be running objdump with --prefix-addresses will
> help, but it may make other thing unambiguous.

[root(a)emilia ~]# objdump --start-address=0x0000000000400474 --stop-address=0x0000000000400496 -dS ./a.out | grep -P ':\t'
400474: 55 push %rbp
400475: 48 89 e5 mov %rsp,%rbp
400478: 89 7d ec mov %edi,-0x14(%rbp)
40047b: 48 89 75 e0 mov %rsi,-0x20(%rbp)
40047f: eb 01 jmp 400482 <main+0xe>
400481: 90 nop
400482: 83 45 fc 01 addl $0x1,-0x4(%rbp)
400486: 81 7d fc 80 96 98 00 cmpl $0x989680,-0x4(%rbp)
40048d: 75 f2 jne 400481 <main+0xd>
40048f: 90 nop
400490: b8 00 00 00 00 mov $0x0,%eax
400495: c9 leaveq
[root(a)emilia ~]# objdump --start-address=0x0000000000400474
--stop-address=0x0000000000400496 -dS ./a.out | grep ':$'
Disassembly of section .text:
0000000000400474 <main>:
add:
[root(a)emilia ~]#

Can you try the attached patch?

With it we get:


[root(a)emilia ~]# perf annotate

------------------------------------------------
Percent | Source code & Disassembly of a.out
------------------------------------------------
:
:
:
: Disassembly of section .text:
:
: 0000000000400474 <main>:
: int main(int argc, char **argv)
: {
0.00 : 400474: 55 push %rbp
0.00 : 400475: 48 89 e5 mov %rsp,%rbp
0.00 : 400478: 89 7d ec mov %edi,-0x14(%rbp)
0.00 : 40047b: 48 89 75 e0 mov %rsi,-0x20(%rbp)
0.00 : 40047f: eb 01 jmp 400482 <main+0xe>
:
: while(1) {
: i++;
: if (i == 10000000)
: goto add;
: }
21.05 : 400481: 90 nop
: int main(int argc, char **argv)
: {
: int i;
:
: while(1) {
: i++;
0.00 : 400482: 83 45 fc 01 addl $0x1,-0x4(%rbp)
: if (i == 10000000)
15.79 : 400486: 81 7d fc 80 96 98 00 cmpl $0x989680,-0x4(%rbp)
63.16 : 40048d: 75 f2 jne 400481 <main+0xd>
: goto add;
0.00 : 40048f: 90 nop
: }
: add:
: return 0;
0.00 : 400490: b8 00 00 00 00 mov $0x0,%eax
: }
0.00 : 400495: c9 leaveq