[PATCH for review] [127/145] i386: move kernel_thread_helper into entry.S

Andi Kleen
2006-08-10T19:43:46Z

r

And add proper CFI annotation to it which was previously
impossible. This prevents "stuck" messages by the dwarf2 unwinder
when reaching the top of a kernel stack.

Cc: jbeulich@novell.com

Signed-off-by: Andi Kleen <ak@suse.de>

---
arch/i386/kernel/entry.S | 15 +++++++++++++++
arch/i386/kernel/process.c | 9 ---------
2 files changed, 15 insertions(+), 9 deletions(-)

Index: linux/arch/i386/kernel/entry.S
===================================================================
--- linux.orig/arch/i386/kernel/entry.S
+++ linux/arch/i386/kernel/entry.S
@@ -946,6 +946,21 @@ ENTRY(arch_unwind_init_running)
ENDPROC(arch_unwind_init_running)
#endif

+ENTRY(kernel_thread_helper)
+ CFI_STARTPROC
+ movl %edx,%eax
+ CFI_REGISTER edx,eax
+ push %edx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET edx,0
+ call *%ebx
+ push %eax
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET eax,0
+ call do_exit
+ CFI_ENDPROC
+ENDPROC(kernel_thread_helper)
+
.section .rodata,"a"
#include "syscall_table.S"

Index: linux/arch/i386/kernel/process.c
===================================================================
--- linux.orig/arch/i386/kernel/process.c
+++ linux/arch/i386/kernel/process.c
@@ -321,15 +321,6 @@ void show_regs(struct pt_regs * regs)
* the "args".
*/
extern void kernel_thread_helper(void);
-__asm__(".section .text\n"
- ".align 4\n"
- "kernel_thread_helper:\n\t"
- "movl %edx,%eax\n\t"
- "pushl %edx\n\t"
- "call *%ebx\n\t"
- "pushl %eax\n\t"
- "call do_exit\n"
- ".previous");

/*
* Create a kernel thread