From: Andi Kleen <ak@suse.de>
Date: Tue, 26 Sep 2006 08:52:35 +0000 (+0200)
Subject: [PATCH] i386: move kernel_thread_helper into entry.S
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=02ba1a32dbd3d406530a17a2643a8f0f8cbf3acc;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

[PATCH] i386: move kernel_thread_helper into entry.S

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.

Includes feedback from Jan Beulich

Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
---

diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index ba22ec8fab54..dede506e5bd0 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -950,6 +950,19 @@ ENTRY(arch_unwind_init_running)
 ENDPROC(arch_unwind_init_running)
 #endif
 
+ENTRY(kernel_thread_helper)
+	pushl $0		# fake return address for unwinder
+	CFI_STARTPROC
+	movl %edx,%eax
+	push %edx
+	CFI_ADJUST_CFA_OFFSET 4
+	call *%ebx
+	push %eax
+	CFI_ADJUST_CFA_OFFSET 4
+	call do_exit
+	CFI_ENDPROC
+ENDPROC(kernel_thread_helper)
+
 .section .rodata,"a"
 #include "syscall_table.S"
 
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index b741c3e1a5eb..220aeca59c3a 100644
--- a/arch/i386/kernel/process.c
+++ b/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