diff options
Diffstat (limited to 'arch/um/kernel/signal_user.c')
-rw-r--r-- | arch/um/kernel/signal_user.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/arch/um/kernel/signal_user.c b/arch/um/kernel/signal_user.c new file mode 100644 index 0000000..62f4578 --- /dev/null +++ b/arch/um/kernel/signal_user.c @@ -0,0 +1,157 @@ +/* + * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#include <stdio.h> +#include <unistd.h> +#include <stdlib.h> +#include <signal.h> +#include <errno.h> +#include <stdarg.h> +#include <string.h> +#include <sys/mman.h> +#include "user_util.h" +#include "kern_util.h" +#include "user.h" +#include "signal_user.h" +#include "signal_kern.h" +#include "sysdep/sigcontext.h" +#include "sigcontext.h" + +void set_sigstack(void *sig_stack, int size) +{ + stack_t stack = ((stack_t) { .ss_flags = 0, + .ss_sp = (__ptr_t) sig_stack, + .ss_size = size - sizeof(void *) }); + + if(sigaltstack(&stack, NULL) != 0) + panic("enabling signal stack failed, errno = %d\n", errno); +} + +void set_handler(int sig, void (*handler)(int), int flags, ...) +{ + struct sigaction action; + va_list ap; + int mask; + + va_start(ap, flags); + action.sa_handler = handler; + sigemptyset(&action.sa_mask); + while((mask = va_arg(ap, int)) != -1){ + sigaddset(&action.sa_mask, mask); + } + va_end(ap); + action.sa_flags = flags; + action.sa_restorer = NULL; + if(sigaction(sig, &action, NULL) < 0) + panic("sigaction failed"); +} + +int change_sig(int signal, int on) +{ + sigset_t sigset, old; + + sigemptyset(&sigset); + sigaddset(&sigset, signal); + sigprocmask(on ? SIG_UNBLOCK : SIG_BLOCK, &sigset, &old); + return(!sigismember(&old, signal)); +} + +/* Both here and in set/get_signal we don't touch SIGPROF, because we must not + * disable profiling; it's safe because the profiling code does not interact + * with the kernel code at all.*/ + +static void change_signals(int type) +{ + sigset_t mask; + + sigemptyset(&mask); + sigaddset(&mask, SIGVTALRM); + sigaddset(&mask, SIGALRM); + sigaddset(&mask, SIGIO); + if(sigprocmask(type, &mask, NULL) < 0) + panic("Failed to change signal mask - errno = %d", errno); +} + +void block_signals(void) +{ + change_signals(SIG_BLOCK); +} + +void unblock_signals(void) +{ + change_signals(SIG_UNBLOCK); +} + +/* These are the asynchronous signals. SIGVTALRM and SIGARLM are handled + * together under SIGVTALRM_BIT. SIGPROF is excluded because we want to + * be able to profile all of UML, not just the non-critical sections. If + * profiling is not thread-safe, then that is not my problem. We can disable + * profiling when SMP is enabled in that case. + */ +#define SIGIO_BIT 0 +#define SIGVTALRM_BIT 1 + +static int enable_mask(sigset_t *mask) +{ + int sigs; + + sigs = sigismember(mask, SIGIO) ? 0 : 1 << SIGIO_BIT; + sigs |= sigismember(mask, SIGVTALRM) ? 0 : 1 << SIGVTALRM_BIT; + sigs |= sigismember(mask, SIGALRM) ? 0 : 1 << SIGVTALRM_BIT; + return(sigs); +} + +int get_signals(void) +{ + sigset_t mask; + + if(sigprocmask(SIG_SETMASK, NULL, &mask) < 0) + panic("Failed to get signal mask"); + return(enable_mask(&mask)); +} + +int set_signals(int enable) +{ + sigset_t mask; + int ret; + + sigemptyset(&mask); + if(enable & (1 << SIGIO_BIT)) + sigaddset(&mask, SIGIO); + if(enable & (1 << SIGVTALRM_BIT)){ + sigaddset(&mask, SIGVTALRM); + sigaddset(&mask, SIGALRM); + } + + /* This is safe - sigprocmask is guaranteed to copy locally the + * value of new_set, do his work and then, at the end, write to + * old_set. + */ + if(sigprocmask(SIG_UNBLOCK, &mask, &mask) < 0) + panic("Failed to enable signals"); + ret = enable_mask(&mask); + sigemptyset(&mask); + if((enable & (1 << SIGIO_BIT)) == 0) + sigaddset(&mask, SIGIO); + if((enable & (1 << SIGVTALRM_BIT)) == 0){ + sigaddset(&mask, SIGVTALRM); + sigaddset(&mask, SIGALRM); + } + if(sigprocmask(SIG_BLOCK, &mask, NULL) < 0) + panic("Failed to block signals"); + + return(ret); +} + +/* + * Overrides for Emacs so that we follow Linus's tabbing style. + * Emacs will notice this stuff at the end of the file and automatically + * adjust the settings for this buffer only. This must remain at the end + * of the file. + * --------------------------------------------------------------------------- + * Local variables: + * c-file-style: "linux" + * End: + */ |