x86: Unspaghettize do_trap()
Cleanup the label maze in this function. Having a
seperate function to first handle the traps that don't
generate a signal makes it easier to convert into
more readable conditional paths.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1348577479-2564-1-git-send-email-fweisbec@gmail.com
[ Fixed 32-bit build failure. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index b481341..6ff7715 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -107,30 +107,45 @@
dec_preempt_count();
}
+static int __kprobes
+do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str,
+ struct pt_regs *regs, long error_code)
+{
+#ifdef CONFIG_X86_32
+ if (regs->flags & X86_VM_MASK) {
+ /*
+ * Traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
+ * On nmi (interrupt 2), do_trap should not be called.
+ */
+ if (trapnr < X86_TRAP_UD) {
+ if (!handle_vm86_trap((struct kernel_vm86_regs *) regs,
+ error_code, trapnr))
+ return 0;
+ }
+ return -1;
+ }
+#endif
+ if (!user_mode(regs)) {
+ if (!fixup_exception(regs)) {
+ tsk->thread.error_code = error_code;
+ tsk->thread.trap_nr = trapnr;
+ die(str, regs, error_code);
+ }
+ return 0;
+ }
+
+ return -1;
+}
+
static void __kprobes
do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
long error_code, siginfo_t *info)
{
struct task_struct *tsk = current;
-#ifdef CONFIG_X86_32
- if (regs->flags & X86_VM_MASK) {
- /*
- * traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
- * On nmi (interrupt 2), do_trap should not be called.
- */
- if (trapnr < X86_TRAP_UD)
- goto vm86_trap;
- goto trap_signal;
- }
-#endif
- if (!user_mode(regs))
- goto kernel_trap;
-
-#ifdef CONFIG_X86_32
-trap_signal:
-#endif
+ if (!do_trap_no_signal(tsk, trapnr, str, regs, error_code))
+ return;
/*
* We want error_code and trap_nr set for userspace faults and
* kernelspace faults which result in die(), but not
@@ -158,23 +173,6 @@
force_sig_info(signr, info, tsk);
else
force_sig(signr, tsk);
- return;
-
-kernel_trap:
- if (!fixup_exception(regs)) {
- tsk->thread.error_code = error_code;
- tsk->thread.trap_nr = trapnr;
- die(str, regs, error_code);
- }
- return;
-
-#ifdef CONFIG_X86_32
-vm86_trap:
- if (handle_vm86_trap((struct kernel_vm86_regs *) regs,
- error_code, trapnr))
- goto trap_signal;
- return;
-#endif
}
#define DO_ERROR(trapnr, signr, str, name) \