From: Breno Leitao <brenohl@br•ibm.com>
To: linuxppc-dev@lists•ozlabs.org
Cc: Gustavo Bueno Romero <gromero@br•ibm.com>
Subject: Different SIGSEGV codes (x86 and ppc64le)
Date: Tue, 19 Jan 2016 18:49:25 -0200 [thread overview]
Message-ID: <569EA155.5070602@br.ibm.com> (raw)
During some debugging, we found that during a stack overflow, the SIGSEGV code
returned is different on Power and Intel.
We were able to narrow down the test case to the follow simple code:
https://github.com/leitao/stack/blob/master/overflow.c
On Power, the SIGSEV si->si_code is 2 (SEGV_ACCERR) , meaning "access error". On
the other way around, the same test on x86 returns si->si_code = 1 (SEGV_MAPERR),
meaning "invalid permission". Any idea why such difference?
Example:
Power
-----
$ gcc overflow.c
$ ./a.out
Got SIGSEGV(2) at address: 0x3fffdd90ffe0
x86
---
$ gcc overflow.c
$ ./a.out
Got SIGSEGV(1) at address: 0x7fff9f089fe8
Thank you!
Breno
next reply other threads:[~2016-01-19 20:49 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-19 20:49 Breno Leitao [this message]
2016-01-19 21:10 ` Different SIGSEGV codes (x86 and ppc64le) Gustavo Bueno Romero
2016-01-20 5:34 ` Michael Ellerman
2016-01-20 18:21 ` Linus Torvalds
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