[PATCH] UML - disable pending signals across a reboot

From: Jeff Dike
Date: Fri Sep 10 2004 - 12:32:47 EST


On reboot, all signals and signal sources are disabled so that late-arriving
signals don't show up after the reboot exec, confusing the new image, which
is not expecting signals yet.

Jeff

Index: 2.6.9-rc1/arch/um/include/irq_user.h
===================================================================
--- 2.6.9-rc1.orig/arch/um/include/irq_user.h 2004-06-16 01:19:37.000000000 -0400
+++ 2.6.9-rc1/arch/um/include/irq_user.h 2004-09-10 13:11:06.000000000 -0400
@@ -14,6 +14,7 @@
extern void free_irq_by_fd(int fd);
extern void reactivate_fd(int fd, int irqnum);
extern void deactivate_fd(int fd, int irqnum);
+extern int deactivate_all_fds(void);
extern void forward_interrupts(int pid);
extern void init_irq_signals(int on_sigstack);
extern void forward_ipi(int fd, int pid);
Index: 2.6.9-rc1/arch/um/include/os.h
===================================================================
--- 2.6.9-rc1.orig/arch/um/include/os.h 2004-09-09 19:46:14.000000000 -0400
+++ 2.6.9-rc1/arch/um/include/os.h 2004-09-10 13:11:06.000000000 -0400
@@ -140,6 +140,7 @@
extern int os_file_modtime(char *file, unsigned long *modtime);
extern int os_pipe(int *fd, int stream, int close_on_exec);
extern int os_set_fd_async(int fd, int owner);
+extern int os_clear_fd_async(int fd);
extern int os_set_fd_block(int fd, int blocking);
extern int os_accept_connection(int fd);
extern int os_create_unix_socket(char *file, int len, int close_on_exec);
Index: 2.6.9-rc1/arch/um/include/time_user.h
===================================================================
--- 2.6.9-rc1.orig/arch/um/include/time_user.h 2004-06-16 01:19:01.000000000 -0400
+++ 2.6.9-rc1/arch/um/include/time_user.h 2004-09-10 13:11:06.000000000 -0400
@@ -11,6 +11,7 @@
extern void set_interval(int timer_type);
extern void idle_sleep(int secs);
extern void enable_timer(void);
+extern void disable_timer(void);
extern unsigned long time_lock(void);
extern void time_unlock(unsigned long);

Index: 2.6.9-rc1/arch/um/kernel/irq_user.c
===================================================================
--- 2.6.9-rc1.orig/arch/um/kernel/irq_user.c 2004-09-09 19:46:14.000000000 -0400
+++ 2.6.9-rc1/arch/um/kernel/irq_user.c 2004-09-10 13:11:06.000000000 -0400
@@ -364,6 +364,20 @@
irq_unlock(flags);
}

+int deactivate_all_fds(void)
+{
+ struct irq_fd *irq;
+ int err;
+
+ for(irq=active_fds;irq != NULL;irq = irq->next){
+ err = os_clear_fd_async(irq->fd);
+ if(err)
+ return(err);
+ }
+
+ return(0);
+}
+
void forward_ipi(int fd, int pid)
{
int err;
Index: 2.6.9-rc1/arch/um/kernel/time.c
===================================================================
--- 2.6.9-rc1.orig/arch/um/kernel/time.c 2004-09-09 19:46:14.000000000 -0400
+++ 2.6.9-rc1/arch/um/kernel/time.c 2004-09-10 13:11:06.000000000 -0400
@@ -54,6 +54,15 @@
errno);
}

+void disable_timer(void)
+{
+ struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
+ if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
+ (setitimer(ITIMER_REAL, &disable, NULL) < 0))
+ printk("disnable_timer - setitimer failed, errno = %d\n",
+ errno);
+}
+
void switch_timers(int to_real)
{
struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
Index: 2.6.9-rc1/arch/um/os-Linux/file.c
===================================================================
--- 2.6.9-rc1.orig/arch/um/os-Linux/file.c 2004-09-09 19:46:14.000000000 -0400
+++ 2.6.9-rc1/arch/um/os-Linux/file.c 2004-09-10 13:11:06.000000000 -0400
@@ -495,6 +495,16 @@
return(0);
}

+int os_clear_fd_async(int fd)
+{
+ int flags = fcntl(fd, F_GETFL);
+
+ flags &= ~(O_ASYNC | O_NONBLOCK);
+ if(fcntl(fd, F_SETFL, flags) < 0)
+ return(-errno);
+ return(0);
+}
+
int os_set_fd_block(int fd, int blocking)
{
int flags;

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