From 885f507317b6c8576ba2e298c2249d27ea6f8404 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Mon, 15 Dec 2008 09:29:33 +0000 Subject: sigaction overhaul as described in docs/sigaction.txt Run tested on i386. --- libc/sysdeps/linux/i386/sigaction.c | 158 +++++++++++++++--------------------- 1 file changed, 65 insertions(+), 93 deletions(-) (limited to 'libc/sysdeps/linux/i386') diff --git a/libc/sysdeps/linux/i386/sigaction.c b/libc/sysdeps/linux/i386/sigaction.c index a69c872a7..602f759a4 100644 --- a/libc/sysdeps/linux/i386/sigaction.c +++ b/libc/sysdeps/linux/i386/sigaction.c @@ -29,115 +29,89 @@ extern __typeof(sigaction) __libc_sigaction; + #if defined __NR_rt_sigaction -/* Experimentally off - libc_hidden_proto(memcpy) */ -extern void restore_rt (void) __asm__ ("__restore_rt") attribute_hidden; -extern void restore (void) __asm__ ("__restore") attribute_hidden; +extern void restore_rt(void) __asm__ ("__restore_rt") attribute_hidden; +extern void restore(void) __asm__ ("__restore") attribute_hidden; /* If ACT is not NULL, change the action for SIG to *ACT. If OACT is not NULL, put the old action for SIG in *OACT. */ -int __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact) +int __libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact) { - int result; - struct kernel_sigaction kact, koact; - enum { - SIGSET_MIN_SIZE = sizeof(kact.sa_mask) < sizeof(act->sa_mask) - ? sizeof(kact.sa_mask) : sizeof(act->sa_mask) - }; + struct sigaction kact; #ifdef SIGCANCEL if (sig == SIGCANCEL) { - __set_errno (EINVAL); + __set_errno(EINVAL); return -1; } #endif - if (act) { - kact.k_sa_handler = act->sa_handler; - memcpy (&kact.sa_mask, &act->sa_mask, SIGSET_MIN_SIZE); - kact.sa_flags = act->sa_flags; - - kact.sa_flags = act->sa_flags | SA_RESTORER; - kact.sa_restorer = ((act->sa_flags & SA_SIGINFO) - ? &restore_rt : &restore); + memcpy(&kact, act, sizeof(kact)); + kact.sa_flags |= SA_RESTORER; + kact.sa_restorer = (act->sa_flags & SA_SIGINFO) ? &restore_rt : &restore; + act = &kact; } - /* NB: kernel (as of 2.6.25) will return EINVAL - * if sizeof(kact.sa_mask) does not match kernel's sizeof(sigset_t) */ - result = __syscall_rt_sigaction(sig, - act ? &kact : NULL, - oact ? &koact : NULL, - sizeof(kact.sa_mask)); - - if (oact && result >= 0) { - oact->sa_handler = koact.k_sa_handler; - memcpy (&oact->sa_mask, &koact.sa_mask, SIGSET_MIN_SIZE); - oact->sa_flags = koact.sa_flags; - oact->sa_restorer = koact.sa_restorer; - } - return result; + * if sizeof(act->sa_mask) does not match kernel's sizeof(sigset_t) */ + return __syscall_rt_sigaction(sig, act, oact, sizeof(act->sa_mask)); } - #else -extern void restore (void) __asm__ ("__restore") attribute_hidden; + +extern void restore(void) __asm__ ("__restore") attribute_hidden; /* If ACT is not NULL, change the action for SIG to *ACT. If OACT is not NULL, put the old action for SIG in *OACT. */ -int __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact) +int __libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact) { - int result; - struct old_kernel_sigaction kact, koact; + int result; + struct old_kernel_sigaction kact, koact; #ifdef SIGCANCEL - if (sig == SIGCANCEL) { - __set_errno (EINVAL); - return -1; - } + if (sig == SIGCANCEL) { + __set_errno(EINVAL); + return -1; + } #endif - - if (act) { - kact.k_sa_handler = act->sa_handler; - kact.sa_mask = act->sa_mask.__val[0]; - kact.sa_flags = act->sa_flags | SA_RESTORER; - kact.sa_restorer = &restore; - } - - __asm__ __volatile__ ("pushl %%ebx\n" - "movl %3, %%ebx\n" - "int $0x80\n" - "popl %%ebx" - : "=a" (result), "=m" (koact) - : "0" (__NR_sigaction), "r" (sig), "m" (kact), - "c" (act ? &kact : 0), - "d" (oact ? &koact : 0)); - - if (result < 0) { - __set_errno(-result); - return -1; - } - - if (oact) { - oact->sa_handler = koact.k_sa_handler; - oact->sa_mask.__val[0] = koact.sa_mask; - oact->sa_flags = koact.sa_flags; - oact->sa_restorer = koact.sa_restorer; - } - return result; + if (act) { + kact.k_sa_handler = act->sa_handler; + kact.sa_mask = act->sa_mask.__val[0]; + kact.sa_flags = act->sa_flags | SA_RESTORER; + kact.sa_restorer = &restore; + } + __asm__ __volatile__ ( + " pushl %%ebx\n" + " movl %3, %%ebx\n" + " int $0x80\n" + " popl %%ebx\n" + : "=a" (result), "=m" (koact) + : "0" (__NR_sigaction), "r" (sig), "m" (kact), + "c" (act ? &kact : NULL), + "d" (oact ? &koact : NULL)); + if (result < 0) { + __set_errno(-result); + return -1; + } + if (oact) { + oact->sa_handler = koact.k_sa_handler; + oact->sa_mask.__val[0] = koact.sa_mask; + oact->sa_flags = koact.sa_flags; + oact->sa_restorer = koact.sa_restorer; + } + return result; } #endif + #ifndef LIBC_SIGACTION -/* libc_hidden_proto(sigaction) */ weak_alias(__libc_sigaction,sigaction) libc_hidden_weak(sigaction) #endif - - /* NOTE: Please think twice before making any changes to the bits of code below. GDB needs some intimate knowledge about it to recognize them as signal trampolines, and make backtraces through @@ -146,33 +120,31 @@ libc_hidden_weak(sigaction) If you ever feel the need to make any changes, please notify the appropriate GDB maintainer. */ -#define RESTORE(name, syscall) RESTORE2 (name, syscall) +#define RESTORE(name, syscall) RESTORE2(name, syscall) #define RESTORE2(name, syscall) \ -__asm__ \ - ( \ - ".text\n" \ - "__" #name ":\n" \ - " movl $" #syscall ", %eax\n" \ - " int $0x80" \ - ); +__asm__ ( \ + ".text\n" \ + "__" #name ":\n" \ + " movl $" #syscall ", %eax\n" \ + " int $0x80\n" \ +); #ifdef __NR_rt_sigaction /* The return code for realtime-signals. */ -RESTORE (restore_rt, __NR_rt_sigreturn) +RESTORE(restore_rt, __NR_rt_sigreturn) #endif #ifdef __NR_sigreturn /* For the boring old signals. */ # undef RESTORE2 # define RESTORE2(name, syscall) \ -__asm__ \ - ( \ - ".text\n" \ - "__" #name ":\n" \ - " popl %eax\n" \ - " movl $" #syscall ", %eax\n" \ - " int $0x80" \ - ); - -RESTORE (restore, __NR_sigreturn) +__asm__ ( \ + ".text\n" \ + "__" #name ":\n" \ + " popl %eax\n" \ + " movl $" #syscall ", %eax\n" \ + " int $0x80\n" \ +); + +RESTORE(restore, __NR_sigreturn) #endif -- cgit v1.2.3