[PATCH 8/16] UML - Code cleanup

From: Jeff Dike
Date: Mon Mar 07 2005 - 14:35:36 EST


From: Bodo Stroesser <bstroesser@xxxxxxxxxxxxxxxxxxx>

Shifting register restore and userspace resume to the
beginning of the userspace loop, we can remove the
identical code done before the loop.

Signed-off-by: Bodo Stroesser <bstroesser@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jeff Dike <jdike@xxxxxxxxxxx>

Index: uml-i386/arch/um/kernel/skas/process.c
===================================================================
--- uml-i386.orig/arch/um/kernel/skas/process.c 2005-03-02 23:39:26.408483443 -0800
+++ uml-i386/arch/um/kernel/skas/process.c 2005-03-02 23:45:55.666136061 -0800
@@ -139,17 +139,20 @@
int err, status, op, pid = userspace_pid[0];
int local_using_sysemu; /*To prevent races if using_sysemu changes under us.*/

- restore_registers(pid, regs);
-
- local_using_sysemu = get_using_sysemu();
+ while(1){
+ restore_registers(pid, regs);

- op = local_using_sysemu ? PTRACE_SYSEMU : PTRACE_SYSCALL;
- err = ptrace(op, pid, 0, 0);
+ /* Now we set local_using_sysemu to be used for one loop */
+ local_using_sysemu = get_using_sysemu();
+
+ op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL));
+
+ err = ptrace(op, pid, 0, 0);
+ if(err)
+ panic("userspace - could not resume userspace process, "
+ "pid=%d, ptrace operation = %d, errno = %d\n",
+ op, errno);

- if(err)
- panic("userspace - PTRACE_%s failed, errno = %d\n",
- local_using_sysemu ? "SYSEMU" : "SYSCALL", errno);
- while(1){
CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
if(err < 0)
panic("userspace - waitpid failed, errno = %d\n",
@@ -187,19 +190,6 @@
/* Avoid -ERESTARTSYS handling in host */
PT_SYSCALL_NR(regs->skas.regs) = -1;
}
-
- restore_registers(pid, regs);
-
- /*Now we ended the syscall, so re-read local_using_sysemu.*/
- local_using_sysemu = get_using_sysemu();
-
- op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL));
-
- err = ptrace(op, pid, 0, 0);
- if(err)
- panic("userspace - PTRACE_%s failed, "
- "errno = %d\n",
- local_using_sysemu ? "SYSEMU" : "SYSCALL", errno);
}
}


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