Re: 2.6.35 regression

[Zeev Tarantov <zeev.tarantov@gmail.com>]

On Thu, Jul 8, 2010 at 16:22, Steven Rostedt <rostedt@goodmis.org> wrote:
> Zeev, can you try to reproduce it with gcc 4.4.
>
> And for now could you send me the output of this:
>
>  objdump -Dr --start-addr 0x`nm vmlinux | grep __start_syscalls_metadata | cut -d' ' -f 1` \
>    --stop-addr 0x`nm vmlinux | grep __stop_syscalls_metadata | cut -d' ' -f 1` vmlinux
>
> You need to go into the directory that has the vmlinux built.
>
> -- Steve

I've just uploaded the disassembly to bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=16353

With gcc 4.4.4 it boots and objdump's output starts with:
Disassembly of section .data:

ffffffff81736898 <__start_syscalls_metadata>:
ffffffff81736898:       a3 55 5f 81 ff ff ff    mov    %eax,0xffffffff815f55
ffffffff8173689f:       ff 00
ffffffff817368a1:       00 00                   add    %al,(%rax)
ffffffff817368a3:       00 06                   add    %al,(%rsi)
ffffffff817368a5:       00 00                   add    %al,(%rax)

With gcc 4.5.1 rev. 161655 objdump shows:
Disassembly of section .data:

ffffffff8173c438 <__start_syscalls_metadata>:
        ...

ffffffff8173c440 <__syscall_meta__mmap>:
ffffffff8173c440:       2b ab 5f 81 ff ff       sub    -0x7ea1(%rbx),%ebp
ffffffff8173c446:       ff                      (bad)
ffffffff8173c447:       ff 00                   incl   (%rax)
ffffffff8173c449:       00 00                   add    %al,(%rax)
ffffffff8173c44b:       00 06                   add    %al,(%rsi)
ffffffff8173c44d:       00 00                   add    %al,(%rax)

I don't know why -D, but that's the output.
Hope it helps.

-Zeev