/*
* 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:
*/
