[PATCH] uml: timer cleanups

set_interval returns an error instead of panicing if setitimer fails.  Some of
its callers now check the return.

enable_timer is largely tt-mode-specific, so it is marked as such, and the
only skas-mode caller is made to call set-interval instead.

user_time_init was a no-value-added wrapper around set_interval, so it is
gone.

Since set_interval is now called from kernel code, callers no longer pass
ITIMER_* to it.  Instead, they pass a flag which is converted into ITIMER_REAL
or ITIMER_VIRTUAL.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 22 insertions, 13 deletions

diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index c73dfa78f943..24fb6d8680e1 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -276,9 +276,11 @@ extern int setjmp_wrapper(void (*proc)(void *, void *), ...);
 
 extern void switch_timers(int to_real);
 extern void idle_sleep(int secs);
+extern int set_interval(int is_virtual);
+#ifdef CONFIG_MODE_TT
 extern void enable_timer(void);
+#endif
 extern void disable_timer(void);
-extern void user_time_init(void);
 extern void uml_idle_timer(void);
 extern unsigned long long os_nsecs(void);
 
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index 552ca1cb9847..d1d799346e04 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -113,12 +113,15 @@ static void register_timer(void)
 
         err = request_irq(TIMER_IRQ, um_timer, IRQF_DISABLED, "timer", NULL);
         if(err != 0)
-                printk(KERN_ERR "timer_init : request_irq failed - "
+                printk(KERN_ERR "register_timer : request_irq failed - "
                        "errno = %d\n", -err);
 
         timer_irq_inited = 1;
 
-        user_time_init();
+        err = set_interval(1);
+        if(err != 0)
+                printk(KERN_ERR "register_timer : set_interval failed - "
+                       "errno = %d\n", -err);
 }
 
 extern void (*late_time_init)(void);
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 88ff0de95cd3..42e3d1ed802c 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -155,11 +155,15 @@ extern int __syscall_stub_start;
 static int userspace_tramp(void *stack)
 {
         void *addr;
+        int err;
 
         ptrace(PTRACE_TRACEME, 0, 0, 0);
 
         init_new_thread_signals();
-        enable_timer();
+        err = set_interval(1);
+        if(err)
+                panic("userspace_tramp - setting timer failed, errno = %d\n",
+                      err);
 
         if(!proc_mm){
                 /* This has a pte, but it can't be mapped in with the usual
diff --git a/arch/um/os-Linux/time.c b/arch/um/os-Linux/time.c
index 7f5ebbadca63..38be096e750f 100644
--- a/arch/um/os-Linux/time.c
+++ b/arch/um/os-Linux/time.c
@@ -17,20 +17,25 @@
 #include "kern_constants.h"
 #include "os.h"
 
-static void set_interval(int timer_type)
+int set_interval(int is_virtual)
 {
         int usec = 1000000/hz();
+        int timer_type = is_virtual ? ITIMER_VIRTUAL : ITIMER_REAL;
         struct itimerval interval = ((struct itimerval) { { 0, usec },
                                                           { 0, usec } });
 
         if(setitimer(timer_type, &interval, NULL) == -1)
-                panic("setitimer failed - errno = %d\n", errno);
+                return -errno;
+
+        return 0;
 }
 
+#ifdef CONFIG_MODE_TT
 void enable_timer(void)
 {
-        set_interval(ITIMER_VIRTUAL);
+        set_interval(1);
 }
+#endif
 
 void disable_timer(void)
 {
@@ -74,7 +79,7 @@ void uml_idle_timer(void)
 
         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
                     SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
-        set_interval(ITIMER_REAL);
+        set_interval(0);
 }
 #endif
 
@@ -94,8 +99,3 @@ void idle_sleep(int secs)
         ts.tv_nsec = 0;
         nanosleep(&ts, NULL);
 }
-
-void user_time_init(void)
-{
-        set_interval(ITIMER_VIRTUAL);
-}