diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/arm/sigaction.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/arm/sigaction.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/arm/sigaction.c b/sysdeps/unix/sysv/linux/arm/sigaction.c new file mode 100644 index 0000000000..76399a2b7a --- /dev/null +++ b/sysdeps/unix/sysv/linux/arm/sigaction.c @@ -0,0 +1,161 @@ +/* Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <errno.h> +#include <signal.h> +#include <string.h> + +#include <sysdep.h> +#include <sys/syscall.h> + +/* 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 <kernel_sigaction.h> + +extern int __syscall_sigaction (int, const struct old_kernel_sigaction *, + struct old_kernel_sigaction *); +extern int __syscall_rt_sigaction (int, const struct kernel_sigaction *, + struct kernel_sigaction *, size_t); + +/* The variable is shared between all wrappers around signal handling + functions which have RT equivalents. */ +int __libc_missing_rt_sigs; + +#define SA_RESTORER 0x04000000 + +/* When RT signals are in use we need to use a different return stub. */ +#ifdef __NR_rt_sigreturn +#define choose_restorer(flags) \ + (flags & SA_SIGINFO) ? &&__default_rt_sa_restorer \ + : &&__default_sa_restorer +#else +#define choose_restorer(flags) \ + &&__default_sa_restorer +#endif + +/* 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 +__sigaction (sig, act, oact) + int sig; + const struct sigaction *act; + struct sigaction *oact; +{ + struct old_kernel_sigaction k_sigact, k_osigact; + int result; + +#ifdef __NR_rt_sigaction + /* First try the RT signals. */ + if (!__libc_missing_rt_sigs) + { + struct kernel_sigaction kact, koact; + int saved_errno = errno; + + if (act) + { + kact.k_sa_handler = act->sa_handler; + memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t)); + kact.sa_flags = act->sa_flags; +# ifdef HAVE_SA_RESTORER + /* If the user specified SA_ONSTACK this means she is trying to + use the old-style stack switching. Unfortunately this + requires the sa_restorer field so we cannot install our own + handler. (In fact the user is likely to be out of luck anyway + since the kernel currently only supports stack switching via + the X/Open sigaltstack interface, but we allow for the + possibility that this might change in the future.) */ + if (kact.sa_flags & (SA_RESTORER | SA_ONSTACK)) + kact.sa_restorer = act->sa_restorer; + else + { + kact.sa_restorer = choose_restorer (kact.sa_flags); + kact.sa_flags |= SA_RESTORER; + } +# endif + } + + /* XXX The size argument hopefully will have to be changed to the + real size of the user-level sigset_t. */ + result = INLINE_SYSCALL (rt_sigaction, 4, sig, act ? &kact : NULL, + oact ? &koact : NULL, _NSIG / 8); + + if (result >= 0 || errno != ENOSYS) + { + if (oact && result >= 0) + { + oact->sa_handler = koact.k_sa_handler; + memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t)); + oact->sa_flags = koact.sa_flags; +# ifdef HAVE_SA_RESTORER + oact->sa_restorer = koact.sa_restorer; +# endif + } + return result; + } + + __set_errno (saved_errno); + __libc_missing_rt_sigs = 1; + } +#endif + + if (act) + { + k_sigact.k_sa_handler = act->sa_handler; + k_sigact.sa_mask = act->sa_mask.__val[0]; + k_sigact.sa_flags = act->sa_flags; +#ifdef HAVE_SA_RESTORER + /* See the comments above for why we test SA_ONSTACK. */ + if (k_sigact.sa_flags & (SA_RESTORER | SA_ONSTACK)) + k_sigact.sa_restorer = act->sa_restorer; + else + { + k_sigact.sa_restorer = choose_restorer (k_sigact.sa_flags); + k_sigact.sa_flags |= SA_RESTORER; + } +#endif + } + result = INLINE_SYSCALL (sigaction, 3, sig, act ? &k_sigact : NULL, + oact ? &k_osigact : NULL); + if (oact && result >= 0) + { + oact->sa_handler = k_osigact.k_sa_handler; + oact->sa_mask.__val[0] = k_osigact.sa_mask; + oact->sa_flags = k_osigact.sa_flags; +#ifdef HAVE_SA_RESTORER + oact->sa_restorer = k_osigact.sa_restorer; +#endif + } + return result; + + /* If no SA_RESTORER function was specified by the application we use + this one. This avoids the need for the kernel to synthesise a return + instruction on the stack, which would involve expensive cache flushes. */ + __default_sa_restorer: + asm volatile ("swi %0" : : "i" (__NR_sigreturn)); + +#ifdef __NR_rt_sigreturn + __default_rt_sa_restorer: + asm volatile ("swi %0" : : "i" (__NR_rt_sigreturn)); +#endif + + /* NOTREACHED */ + return -1; +} + +weak_alias (__sigaction, sigaction) |