2004-11-12 23:56:32

by Jeff Dike

Subject: [PATCH 7/11] - UML - fix setting of interrupted syscall return value

>From Bodo Stroesser - handle_signal now checks whether it is being called
from a system call invocation.

Signed-off-by: Jeff Dike <[email protected]>

Index: 2.6.9/arch/um/kernel/signal_kern.c
===================================================================
--- 2.6.9.orig/arch/um/kernel/signal_kern.c 2004-11-12 16:24:17.000000000 -0500
+++ 2.6.9/arch/um/kernel/signal_kern.c 2004-11-12 18:05:27.000000000 -0500
@@ -44,45 +44,37 @@
{
void (*restorer)(void);
unsigned long sp;
- int err, error, ret;
+ int err;

- error = PT_REGS_SYSCALL_RET(&current->thread.regs);
- ret = 0;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
- switch(error){
- case -ERESTART_RESTARTBLOCK:
- case -ERESTARTNOHAND:
- ret = -EINTR;
- break;
-
- case -ERESTARTSYS:
- if (!(ka->sa.sa_flags & SA_RESTART)) {
- ret = -EINTR;
+
+ /* Did we come from a system call? */
+ if(PT_REGS_SYSCALL_NR(regs) >= 0){
+ /* If so, check system call restarting.. */
+ switch(PT_REGS_SYSCALL_RET(regs)){
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ PT_REGS_SYSCALL_RET(regs) = -EINTR;
break;
- }
+
+ case -ERESTARTSYS:
+ if (!(ka->sa.sa_flags & SA_RESTART)) {
+ PT_REGS_SYSCALL_RET(regs) = -EINTR;
+ break;
+ }
/* fallthrough */
- case -ERESTARTNOINTR:
- PT_REGS_RESTART_SYSCALL(regs);
- PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
-
- /* This is because of the UM_SET_SYSCALL_RETURN and the fact
- * that on i386 the system call number and return value are
- * in the same register. When the system call restarts, %eax
- * had better have the system call number in it. Since the
- * return value doesn't matter (except that it shouldn't be
- * -ERESTART*), we'll stick the system call number there.
- */
- ret = PT_REGS_SYSCALL_NR(regs);
- break;
+ case -ERESTARTNOINTR:
+ PT_REGS_RESTART_SYSCALL(regs);
+ PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
+ break;
+ }
}

sp = PT_REGS_SP(regs);
if((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
sp = current->sas_ss_sp + current->sas_ss_size;

- if(error != 0) PT_REGS_SET_SYSCALL_RETURN(regs, ret);
-
if (ka->sa.sa_flags & SA_RESTORER)
restorer = ka->sa.sa_restorer;
else restorer = NULL;