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/x86_64/sigaction.c | 89 ++++++++++++++--------------------- 1 file changed, 35 insertions(+), 54 deletions(-) (limited to 'libc/sysdeps/linux/x86_64') diff --git a/libc/sysdeps/linux/x86_64/sigaction.c b/libc/sysdeps/linux/x86_64/sigaction.c index 58466c8ef..d1adbc4be 100644 --- a/libc/sysdeps/linux/x86_64/sigaction.c +++ b/libc/sysdeps/linux/x86_64/sigaction.c @@ -25,9 +25,6 @@ #include -/* The difference here is that the sigaction structure used in the - kernel is not the same as we use in the libc. Therefore we must - translate it here. */ #include /* We do not globally define the SA_RESTORER flag so do it here. */ @@ -35,64 +32,47 @@ extern __typeof(sigaction) __libc_sigaction; + #ifdef __NR_rt_sigaction + /* Using the hidden attribute here does not change the code but it helps to avoid warnings. */ -extern void restore_rt (void) __asm__ ("__restore_rt") attribute_hidden; -extern void restore (void) __asm__ ("__restore") attribute_hidden; - -/* Experimentally off - libc_hidden_proto(memcpy) */ +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) +__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; 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 | SA_RESTORER; - + memcpy(&kact, act, sizeof(kact)); + kact.sa_flags |= SA_RESTORER; kact.sa_restorer = &restore_rt; + 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 = INLINE_SYSCALL (rt_sigaction, 4, 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 INLINE_SYSCALL(rt_sigaction, 4, 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) +__libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact) { int result; struct old_kernel_sigaction kact, koact; #ifdef SIGCANCEL if (sig == SIGCANCEL) { - __set_errno (EINVAL); + __set_errno(EINVAL); return -1; } #endif @@ -103,18 +83,16 @@ __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact) kact.sa_flags = act->sa_flags | SA_RESTORER; kact.sa_restorer = &restore; } - - __asm__ __volatile__ ("syscall\n" - : "=a" (result) - : "0" (__NR_sigaction), "mr" (sig), - "c" (act ? &kact : 0), - "d" (oact ? &koact : 0)); - + __asm__ __volatile__ ( + "syscall\n" + : "=a" (result) + : "0" (__NR_sigaction), "mr" (sig), + "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; @@ -123,14 +101,16 @@ __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact) } 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 @@ -139,18 +119,19 @@ 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 RESTORE2(name, syscall) \ -__asm__ ( \ - ".text\n" \ - "__" #name ":\n" \ - " movq $" #syscall ", %rax\n" \ - " syscall\n" \ - ); +#define RESTORE(name, syscall) RESTORE2(name, syscall) +#define RESTORE2(name, syscall) \ +__asm__ ( \ + ".text\n" \ + "__" #name ":\n" \ + " movq $" #syscall ", %rax\n" \ + " syscall\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 -RESTORE (restore, __NR_sigreturn) +RESTORE(restore, __NR_sigreturn) #endif -- cgit v1.2.3