kernel_optimize_test/include/asm-i386/signal.h
Constantine Gavrilov b7fd1edd2c [PATCH] x86: fix sigaddset() inline asm memory constraint
Due to incomplete memory constraints, gcc would miscompile code with
sigaddset on i386 if sig arg was const.

A quote form Jakub to make the issue clear:

 "You need either
	__asm__("btsl %1,%0" : "+m"(*set) : "Ir"(_sig-1) : "cc");
  or
	__asm__("btsl %1,%0" : "=m"(*set) : "Ir"(_sig-1), "m"(*set) : "cc");
  because the btsl instruction doesn't just set the memory to some
  value, but needs to read its previous content as well.  If you don't
  tell that fact to GCC, GCC is of course free to optimize as if the asm
  was just setting the value and not depended on the previous value."

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-17 08:42:26 -08:00

234 lines
5.3 KiB
C

#ifndef _ASMi386_SIGNAL_H
#define _ASMi386_SIGNAL_H
#include <linux/types.h>
#include <linux/linkage.h>
#include <linux/time.h>
#include <linux/compiler.h>
/* Avoid too many header ordering problems. */
struct siginfo;
#ifdef __KERNEL__
/* Most things should be clean enough to redefine this at will, if care
is taken to make libc match. */
#define _NSIG 64
#define _NSIG_BPW 32
#define _NSIG_WORDS (_NSIG / _NSIG_BPW)
typedef unsigned long old_sigset_t; /* at least 32 bits */
typedef struct {
unsigned long sig[_NSIG_WORDS];
} sigset_t;
#else
/* Here we must cater to libcs that poke about in kernel headers. */
#define NSIG 32
typedef unsigned long sigset_t;
#endif /* __KERNEL__ */
#define SIGHUP 1
#define SIGINT 2
#define SIGQUIT 3
#define SIGILL 4
#define SIGTRAP 5
#define SIGABRT 6
#define SIGIOT 6
#define SIGBUS 7
#define SIGFPE 8
#define SIGKILL 9
#define SIGUSR1 10
#define SIGSEGV 11
#define SIGUSR2 12
#define SIGPIPE 13
#define SIGALRM 14
#define SIGTERM 15
#define SIGSTKFLT 16
#define SIGCHLD 17
#define SIGCONT 18
#define SIGSTOP 19
#define SIGTSTP 20
#define SIGTTIN 21
#define SIGTTOU 22
#define SIGURG 23
#define SIGXCPU 24
#define SIGXFSZ 25
#define SIGVTALRM 26
#define SIGPROF 27
#define SIGWINCH 28
#define SIGIO 29
#define SIGPOLL SIGIO
/*
#define SIGLOST 29
*/
#define SIGPWR 30
#define SIGSYS 31
#define SIGUNUSED 31
/* These should not be considered constants from userland. */
#define SIGRTMIN 32
#define SIGRTMAX _NSIG
/*
* SA_FLAGS values:
*
* SA_ONSTACK indicates that a registered stack_t will be used.
* SA_INTERRUPT is a no-op, but left due to historical reasons. Use the
* SA_RESTART flag to get restarting signals (which were the default long ago)
* SA_NOCLDSTOP flag to turn off SIGCHLD when children stop.
* SA_RESETHAND clears the handler when the signal is delivered.
* SA_NOCLDWAIT flag on SIGCHLD to inhibit zombies.
* SA_NODEFER prevents the current signal from being masked in the handler.
*
* SA_ONESHOT and SA_NOMASK are the historical Linux names for the Single
* Unix names RESETHAND and NODEFER respectively.
*/
#define SA_NOCLDSTOP 0x00000001u
#define SA_NOCLDWAIT 0x00000002u
#define SA_SIGINFO 0x00000004u
#define SA_ONSTACK 0x08000000u
#define SA_RESTART 0x10000000u
#define SA_NODEFER 0x40000000u
#define SA_RESETHAND 0x80000000u
#define SA_NOMASK SA_NODEFER
#define SA_ONESHOT SA_RESETHAND
#define SA_INTERRUPT 0x20000000 /* dummy -- ignored */
#define SA_RESTORER 0x04000000
/*
* sigaltstack controls
*/
#define SS_ONSTACK 1
#define SS_DISABLE 2
#define MINSIGSTKSZ 2048
#define SIGSTKSZ 8192
#include <asm-generic/signal.h>
#ifdef __KERNEL__
struct old_sigaction {
__sighandler_t sa_handler;
old_sigset_t sa_mask;
unsigned long sa_flags;
__sigrestore_t sa_restorer;
};
struct sigaction {
__sighandler_t sa_handler;
unsigned long sa_flags;
__sigrestore_t sa_restorer;
sigset_t sa_mask; /* mask last for extensibility */
};
struct k_sigaction {
struct sigaction sa;
};
#else
/* Here we must cater to libcs that poke about in kernel headers. */
struct sigaction {
union {
__sighandler_t _sa_handler;
void (*_sa_sigaction)(int, struct siginfo *, void *);
} _u;
sigset_t sa_mask;
unsigned long sa_flags;
void (*sa_restorer)(void);
};
#define sa_handler _u._sa_handler
#define sa_sigaction _u._sa_sigaction
#endif /* __KERNEL__ */
typedef struct sigaltstack {
void __user *ss_sp;
int ss_flags;
size_t ss_size;
} stack_t;
#ifdef __KERNEL__
#include <asm/sigcontext.h>
#define __HAVE_ARCH_SIG_BITOPS
#define sigaddset(set,sig) \
(__builtin_constant_p(sig) ? \
__const_sigaddset((set),(sig)) : \
__gen_sigaddset((set),(sig)))
static __inline__ void __gen_sigaddset(sigset_t *set, int _sig)
{
__asm__("btsl %1,%0" : "+m"(*set) : "Ir"(_sig - 1) : "cc");
}
static __inline__ void __const_sigaddset(sigset_t *set, int _sig)
{
unsigned long sig = _sig - 1;
set->sig[sig / _NSIG_BPW] |= 1 << (sig % _NSIG_BPW);
}
#define sigdelset(set,sig) \
(__builtin_constant_p(sig) ? \
__const_sigdelset((set),(sig)) : \
__gen_sigdelset((set),(sig)))
static __inline__ void __gen_sigdelset(sigset_t *set, int _sig)
{
__asm__("btrl %1,%0" : "+m"(*set) : "Ir"(_sig - 1) : "cc");
}
static __inline__ void __const_sigaddset(sigset_t *set, int _sig)
{
unsigned long sig = _sig - 1;
set->sig[sig / _NSIG_BPW] &= ~(1 << (sig % _NSIG_BPW));
}
static __inline__ int __const_sigismember(sigset_t *set, int _sig)
{
unsigned long sig = _sig - 1;
return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
}
static __inline__ int __gen_sigismember(sigset_t *set, int _sig)
{
int ret;
__asm__("btl %2,%1\n\tsbbl %0,%0"
: "=r"(ret) : "m"(*set), "Ir"(_sig-1) : "cc");
return ret;
}
#define sigismember(set,sig) \
(__builtin_constant_p(sig) ? \
__const_sigismember((set),(sig)) : \
__gen_sigismember((set),(sig)))
static __inline__ int sigfindinword(unsigned long word)
{
__asm__("bsfl %1,%0" : "=r"(word) : "rm"(word) : "cc");
return word;
}
struct pt_regs;
extern int FASTCALL(do_signal(struct pt_regs *regs, sigset_t *oldset));
#define ptrace_signal_deliver(regs, cookie) \
do { \
if (current->ptrace & PT_DTRACE) { \
current->ptrace &= ~PT_DTRACE; \
(regs)->eflags &= ~TF_MASK; \
} \
} while (0)
#endif /* __KERNEL__ */
#endif