diff options
author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-04-12 14:48:25 +0300 |
---|---|---|
committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-04-17 11:36:12 +0300 |
commit | fae764912153065ea55eda47f834e0764a54df94 (patch) | |
tree | e617ff5bb25474858e2ec5a16ec6685bb4eb6307 /arch/s390/include | |
parent | 49d23a851d62c03daebae2d245dcc9b07dbfa89f (diff) | |
download | linux-fae764912153065ea55eda47f834e0764a54df94.tar.xz |
s390/signal: cleanup uapi struct sigaction
The struct sigaction for user space in arch/s390/include/uapi/asm/signal.h
is ill defined. The kernel uses two structures 'struct sigaction' and
'struct old_sigaction', the correlation in the kernel for both 31 and
64 bit is as follows
sys_sigaction -> struct old_sigaction
sys_rt_sigaction -> struct sigaction
The correlation of the (single) uapi definition for 'struct sigaction'
under '#ifndef __KERNEL__':
31-bit: sys_sigaction -> uapi struct sigaction
31-bit: sys_rt_sigaction -> no structure available
64-bit: sys_sigaction -> no structure available
64-bit: sys_rt_sigaction -> uapi struct sigaction
This is quite confusing. To make it a bit less confusing make the
uapi definition of 'struct sigaction' usable for sys_rt_sigaction for
both 31-bit and 64-bit.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include')
-rw-r--r-- | arch/s390/include/uapi/asm/signal.h | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/arch/s390/include/uapi/asm/signal.h b/arch/s390/include/uapi/asm/signal.h index c57f9d28d894..9a14a611ed82 100644 --- a/arch/s390/include/uapi/asm/signal.h +++ b/arch/s390/include/uapi/asm/signal.h @@ -97,22 +97,31 @@ typedef unsigned long sigset_t; #include <asm-generic/signal-defs.h> #ifndef __KERNEL__ -/* Here we must cater to libcs that poke about in kernel headers. */ +/* + * There are two system calls in regard to sigaction, sys_rt_sigaction + * and sys_sigaction. Internally the kernel uses the struct old_sigaction + * for the older sys_sigaction system call, and the kernel version of the + * struct sigaction for the newer sys_rt_sigaction. + * + * The uapi definition for struct sigaction has made a strange distinction + * between 31-bit and 64-bit in the past. For 64-bit the uapi structure + * looks like the kernel struct sigaction, but for 31-bit it used to + * look like the kernel struct old_sigaction. That practically made the + * structure unusable for either system call. To get around this problem + * the glibc always had its own definitions for the sigaction structures. + * + * The current struct sigaction uapi definition below is suitable for the + * sys_rt_sigaction system call only. + */ struct sigaction { union { __sighandler_t _sa_handler; void (*_sa_sigaction)(int, struct siginfo *, void *); } _u; -#ifndef __s390x__ /* lovely */ - sigset_t sa_mask; - unsigned long sa_flags; - void (*sa_restorer)(void); -#else /* __s390x__ */ unsigned long sa_flags; void (*sa_restorer)(void); sigset_t sa_mask; -#endif /* __s390x__ */ }; #define sa_handler _u._sa_handler |