x86, debug: remove the confusing entry in call trace
authorjia zhang <jia.zhang2008@gmail.com>
Sun, 23 Nov 2008 14:47:10 +0000 (22:47 +0800)
committerIngo Molnar <mingo@elte.hu>
Sun, 23 Nov 2008 19:03:36 +0000 (20:03 +0100)
commit5f5db591326779a80cfe490c5d6b6ce9fac08b31
tree4d599ae5e0439050c13023a47b2ee71443efd5e9
parentf377fa123d0ec621e8e361ecc3f2a8ee70e81a2e
x86, debug: remove the confusing entry in call trace

Impact: improve backtrace quality

avoid the confusion in call trace because of the lack of padding at the
tail of function.

When do_exit gets called, the return address behind call instruction is
pushed into stack. If something get wrong in do_exit, for x86_64, the
entry "kernel_execve +0x00/0xXX" rather than "child_rip +0xYY/0xZZ" is
in the call trace.

That looks confusing, so add a u2d to make the return address still part
of the original call site. (This also catches any instances of us returning
from that function somehow.)

Signed-off-by: jia zhang <jia.zhang2008@gmail.com>
Acked-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/entry_32.S
arch/x86/kernel/entry_64.S