Comment 3 for bug 339743
Revision history for this message
| Anders Kaseorg (andersk) wrote Re: Jaunty i386 popen() misbehaves on Lenny 2.6.26-1-amd64 kernel | #3 |
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35a32c5
(Get the code!)
I reproduced this with a vanilla v2.6.26 kernel (on x86_64 with defconfig). I used git bisect to find the first commit on which the problem is exhibited:
commit 8ab32bb89b5b9bf
Author: Roland McGrath <email address hidden>
Date: Sun Mar 16 21:57:41 2008 -0700
x86: ia32 ptrace vs -ENOSYS
When we're stopped at syscall entry tracing, ptrace can change the %eax
value from -ENOSYS to something else. If no system call is actually made
because the syscall number (now in orig_eax) is bad, then the %eax value
set by ptrace should be returned to the user. But, instead it gets reset
to -ENOSYS again. This is a regression from the native 32-bit kernel.
This change fixes it by leaving the return value alone after entry tracing.
Signed-off-by: Roland McGrath <email address hidden>
Signed-off-by: Ingo Molnar <email address hidden>