From: Nick Owens <mischief@9.offblast.org>
To: 9front@9front.org
Subject: profiling bug on amd64
Date: Sun, 16 Feb 2014 22:11:31 -0800 [thread overview]
Message-ID: <20140217061131.GF25422@iota.offblast.org> (raw)
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when attempting to profile a program on amd64 (games/nes), there's a
problem where function arguments fail to be restored by the profiling
code.
acid: lstk()
_tas()+0x5 /sys/src/libc/amd64/tas.s:5
lock(lk=0x0)+0x13 /sys/src/libc/port/lock.c:10
i=0x206b9700000000
atexit(f=0x0)+0x18 /sys/src/libc/port/atexit.c:21
i=0x205f9f00000000
_profmain()+0x18d /sys/src/libc/port/profile.c:268
n=0x7d0
f=0x7d0ffffffff
ename=0x0
_mainp+0x2c /sys/src/libc/amd64/main9p.s:12
obviously something is wrong here, with f=0x0 and i=0x205f9f00000000
in atexit.
but, if you move #pragma profile off up a little ways before the
definition of atexit in /sys/src/libc/port/atexit.c, you get the same
problem in lock() still.
acid: lstk()
_tas()+0x5 /sys/src/libc/amd64/tas.s:5
lock(lk=0x0)+0x13 /sys/src/libc/port/lock.c:10
i=0x206b9200000000
atexit(f=0x205a6e)+0x13 /sys/src/libc/port/atexit.c:23
i=0x205f9f00000000
_profmain()+0x18d /sys/src/libc/port/profile.c:268
n=0x7d0
f=0x7d0ffffffff
ename=0x0
_mainp+0x2c /sys/src/libc/amd64/main9p.s:12
here, the argument to atexit is valid, but lock's argument is still zero,
so something in the profiling code is certainly affecting the program's behavior.
mischief
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next reply other threads:[~2014-02-17 6:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-17 6:11 Nick Owens [this message]
2014-02-17 6:18 ` [9front] " Nick Owens
2014-02-17 18:58 ` Nick Owens
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