uml: rename os_{read_write}_file_k back to os_{read_write}_file

[karo-tx-linux.git] / arch / um / kernel / tt / process_kern.c

diff --git a/arch/um/kernel/tt/process_kern.c b/arch/um/kernel/tt/process_kern.c
index 62535303aa277233241650a8c0a8686d1a6fb9c8..c631303cb800cf80a8593a22836b1ee47cf7f7f6 100644 (file)
--- a/arch/um/kernel/tt/process_kern.c
+++ b/arch/um/kernel/tt/process_kern.c
@@ -14,11 +14,9 @@
 #include "asm/tlbflush.h"
 #include "irq_user.h"
 #include "kern_util.h"
-#include "user_util.h"
 #include "os.h"
 #include "kern.h"
 #include "sigcontext.h"
-#include "time_user.h"
 #include "mem_user.h"
 #include "tlb.h"
 #include "mode.h"
@@ -52,6 +50,13 @@ void switch_to_tt(void *prev, void *next)
 
        c = 0;
 
+       /* Notice that here we "up" the semaphore on which "to" is waiting, and
+        * below (the read) we wait on this semaphore (which is implemented by
+        * switch_pipe) and go sleeping. Thus, after that, we have resumed in
+        * "to", and can't use any more the value of "from" (which is outdated),
+        * nor the value in "to" (since it was the task which stole us the CPU,
+        * which we don't care about). */
+
        err = os_write_file(to->thread.mode.tt.switch_pipe[1], &c, sizeof(c));
        if(err != sizeof(c))
                panic("write of switch_pipe failed, err = %d", -err);
@@ -59,7 +64,8 @@ void switch_to_tt(void *prev, void *next)
        if(from->thread.mode.tt.switch_pipe[0] == -1)
                os_kill_process(os_getpid(), 0);
 
-       err = os_read_file(from->thread.mode.tt.switch_pipe[0], &c, sizeof(c));
+       err = os_read_file(from->thread.mode.tt.switch_pipe[0], &c,
+                            sizeof(c));
        if(err != sizeof(c))
                panic("read of switch_pipe failed, errno = %d", -err);
 
@@ -78,7 +84,7 @@ void switch_to_tt(void *prev, void *next)
        change_sig(SIGALRM, alrm);
        change_sig(SIGPROF, prof);
 
-       arch_switch();
+       arch_switch_to_tt(prev_sched, current);
 
        flush_tlb_all();
        local_irq_restore(flags);
@@ -113,7 +119,7 @@ void suspend_new_thread(int fd)
                panic("read failed in suspend_new_thread, err = %d", -err);
 }
 
-void schedule_tail(task_t *prev);
+void schedule_tail(struct task_struct *prev);
 
 static void new_thread_handler(int sig)
 {
@@ -136,13 +142,12 @@ static void new_thread_handler(int sig)
                schedule_tail(current->thread.prev_sched);
        current->thread.prev_sched = NULL;
 
-       init_new_thread_signals(1);
+       init_new_thread_signals();
        enable_timer();
        free_page(current->thread.temp_stack);
        set_cmdline("(kernel thread)");
 
        change_sig(SIGUSR1, 1);
-       change_sig(SIGVTALRM, 1);
        change_sig(SIGPROF, 1);
        local_irq_enable();
        if(!run_kernel_thread(fn, arg, &current->thread.exec_buf))