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| author | Eric W. Biederman <ebiederm@xmission.com> | 2017-07-17 04:04:58 +0300 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2017-07-20 03:13:14 +0300 |
| commit | cc9f72e474a4da365896d0e528da324f205e8b31 (patch) | |
| tree | cda3b38a86ae57b171c6094a6ef405b17ac75260 /arch/sparc/include | |
| parent | 80dce5e37493029e1fb7f890b960264ba9a46fe4 (diff) | |
| download | linux-cc9f72e474a4da365896d0e528da324f205e8b31.tar.xz | |
signal/sparc: Document a conflict with SI_USER with SIGFPE
Setting si_code to __SI_FAULT results in a userspace seeing
an si_code of 0. This is the same si_code as SI_USER. Posix
and common sense requires that SI_USER not be a signal specific
si_code. As such this use of 0 for the si_code is a pretty
horribly broken ABI.
This was introduced in 2.3.41 so this mess has had a long time for
people to be able to start depending on it.
As this bug has existed for 17 years already I don't know if it is
worth fixing. It is definitely worth documenting what is going
on so that no one decides to copy this bad decision.
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'arch/sparc/include')
| -rw-r--r-- | arch/sparc/include/uapi/asm/siginfo.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/sparc/include/uapi/asm/siginfo.h b/arch/sparc/include/uapi/asm/siginfo.h index 2d9b79ccaa50..da2126e0c536 100644 --- a/arch/sparc/include/uapi/asm/siginfo.h +++ b/arch/sparc/include/uapi/asm/siginfo.h @@ -17,6 +17,13 @@ #define SI_NOINFO 32767 /* no information in siginfo_t */ /* + * SIGFPE si_codes + */ +#ifdef __KERNEL__ +#define FPE_FIXME (__SI_FAULT|0) /* Broken dup of SI_USER */ +#endif /* __KERNEL__ */ + +/* * SIGEMT si_codes */ #define EMT_TAGOVF (__SI_FAULT|1) /* tag overflow */ |