android_kernel_xiaomi_sm8350/arch/um/os-Linux/signal.c
Jeff Dike aceb343464 [PATCH] uml: timer initialization cleanup
This cleans up the mess that is the timer initialization.  There used to be
two timer handlers - one that basically ran during delay loop calibration and
one that handled the timer afterwards.  There were also two sets of timer
initialization code - one that starts in user code and calls into the kernel
side of the house, and one that starts in kernel code and calls user code.

This eliminates one timer handler and consolidates the two sets of
initialization code.

[akpm@osdl.org: use new INTF_ flags]
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:23 -07:00

238 lines
4.8 KiB
C

/*
* Copyright (C) 2004 PathScale, Inc
* Licensed under the GPL
*/
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <stdarg.h>
#include <string.h>
#include <sys/mman.h>
#include "user_util.h"
#include "user.h"
#include "signal_kern.h"
#include "sysdep/sigcontext.h"
#include "sysdep/signal.h"
#include "sigcontext.h"
#include "mode.h"
#include "os.h"
/* 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 SIGIO_MASK (1 << SIGIO_BIT)
#define SIGVTALRM_BIT 1
#define SIGVTALRM_MASK (1 << SIGVTALRM_BIT)
#define SIGALRM_BIT 2
#define SIGALRM_MASK (1 << SIGALRM_BIT)
static int signals_enabled = 1;
static int pending = 0;
void sig_handler(ARCH_SIGHDLR_PARAM)
{
struct sigcontext *sc;
int enabled;
/* Must be the first thing that this handler does - x86_64 stores
* the sigcontext in %rdx, and we need to save it before it has a
* chance to get trashed.
*/
ARCH_GET_SIGCONTEXT(sc, sig);
enabled = signals_enabled;
if(!enabled && (sig == SIGIO)){
pending |= SIGIO_MASK;
return;
}
block_signals();
CHOOSE_MODE_PROC(sig_handler_common_tt, sig_handler_common_skas,
sig, sc);
set_signals(enabled);
}
extern int timer_irq_inited;
static void real_alarm_handler(int sig, struct sigcontext *sc)
{
if(!timer_irq_inited){
signals_enabled = 1;
return;
}
if(sig == SIGALRM)
switch_timers(0);
CHOOSE_MODE_PROC(sig_handler_common_tt, sig_handler_common_skas,
sig, sc);
if(sig == SIGALRM)
switch_timers(1);
}
void alarm_handler(ARCH_SIGHDLR_PARAM)
{
struct sigcontext *sc;
int enabled;
ARCH_GET_SIGCONTEXT(sc, sig);
enabled = signals_enabled;
if(!signals_enabled){
if(sig == SIGVTALRM)
pending |= SIGVTALRM_MASK;
else pending |= SIGALRM_MASK;
return;
}
block_signals();
real_alarm_handler(sig, sc);
set_signals(enabled);
}
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 remove_sigstack(void)
{
stack_t stack = ((stack_t) { .ss_flags = SS_DISABLE,
.ss_sp = NULL,
.ss_size = 0 });
if(sigaltstack(&stack, NULL) != 0)
panic("disabling signal stack failed, errno = %d\n", errno);
}
void set_handler(int sig, void (*handler)(int), int flags, ...)
{
struct sigaction action;
va_list ap;
sigset_t sig_mask;
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 - errno = %d\n", errno);
sigemptyset(&sig_mask);
sigaddset(&sig_mask, sig);
if(sigprocmask(SIG_UNBLOCK, &sig_mask, NULL) < 0)
panic("sigprocmask failed - errno = %d\n", errno);
}
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));
}
void block_signals(void)
{
signals_enabled = 0;
}
void unblock_signals(void)
{
int save_pending;
if(signals_enabled == 1)
return;
/* We loop because the IRQ handler returns with interrupts off. So,
* interrupts may have arrived and we need to re-enable them and
* recheck pending.
*/
while(1){
/* Save and reset save_pending after enabling signals. This
* way, pending won't be changed while we're reading it.
*/
signals_enabled = 1;
save_pending = pending;
if(save_pending == 0)
return;
pending = 0;
/* We have pending interrupts, so disable signals, as the
* handlers expect them off when they are called. They will
* be enabled again above.
*/
signals_enabled = 0;
/* Deal with SIGIO first because the alarm handler might
* schedule, leaving the pending SIGIO stranded until we come
* back here.
*/
if(save_pending & SIGIO_MASK)
CHOOSE_MODE_PROC(sig_handler_common_tt,
sig_handler_common_skas, SIGIO, NULL);
if(save_pending & SIGALRM_MASK)
real_alarm_handler(SIGALRM, NULL);
if(save_pending & SIGVTALRM_MASK)
real_alarm_handler(SIGVTALRM, NULL);
}
}
int get_signals(void)
{
return signals_enabled;
}
int set_signals(int enable)
{
int ret;
if(signals_enabled == enable)
return enable;
ret = signals_enabled;
if(enable)
unblock_signals();
else block_signals();
return ret;
}
void os_usr1_signal(int on)
{
change_sig(SIGUSR1, on);
}