[REFACTOR] kretprobe_trampoline() for x86

Change-Id: I8035cf2696a0b56d4cb5f30c787e2ac98eccad45
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>

diff --git a/kprobe/arch/asm-x86/swap_kprobes.c b/kprobe/arch/asm-x86/swap_kprobes.c
index d302ca9..cd96cf2 100644 (file)
--- a/kprobe/arch/asm-x86/swap_kprobes.c
+++ b/kprobe/arch/asm-x86/swap_kprobes.c
@@ -54,50 +54,55 @@ static void (*swap_show_registers)(struct pt_regs * regs);
 /** Stack address. */
 #define stack_addr(regs) ((unsigned long *)kernel_stack_pointer(regs))
 
+
+#define SWAP_SAVE_REGS_STRING                  \
+       /* Skip cs, ip, orig_ax and gs. */      \
+       "subl $16, %esp\n"                      \
+       "pushl %fs\n"                           \
+       "pushl %es\n"                           \
+       "pushl %ds\n"                           \
+       "pushl %eax\n"                          \
+       "pushl %ebp\n"                          \
+       "pushl %edi\n"                          \
+       "pushl %esi\n"                          \
+       "pushl %edx\n"                          \
+       "pushl %ecx\n"                          \
+       "pushl %ebx\n"
+#define SWAP_RESTORE_REGS_STRING               \
+       "popl %ebx\n"                           \
+       "popl %ecx\n"                           \
+       "popl %edx\n"                           \
+       "popl %esi\n"                           \
+       "popl %edi\n"                           \
+       "popl %ebp\n"                           \
+       "popl %eax\n"                           \
+       /* Skip ds, es, fs, gs, orig_ax, and ip. Note: don't pop cs here*/\
+       "addl $24, %esp\n"
+
+
 /*
  * Function return probe trampoline:
  *      - init_kprobes() establishes a probepoint here
  *      - When the probed function returns, this probe
  *        causes the handlers to fire
  */
-static __used void swap_kretprobe_trampoline_holder(void)
-{
-       asm volatile(".global swap_kretprobe_trampoline\n"
-                       "swap_kretprobe_trampoline:\n"
-                       "       pushf\n"
-                       /* skip cs, ip, orig_ax and gs. */
-                       "       subl $16, %esp\n"
-                       "       pushl %fs\n"
-                       "       pushl %es\n"
-                       "       pushl %ds\n"
-                       "       pushl %eax\n"
-                       "       pushl %ebp\n"
-                       "       pushl %edi\n"
-                       "       pushl %esi\n"
-                       "       pushl %edx\n"
-                       "       pushl %ecx\n"
-                       "       pushl %ebx\n"
-                       "       movl %esp, %eax\n"
-                       "       call trampoline_probe_handler_x86\n"
-                       /* move eflags to cs */
-                       "       movl 56(%esp), %edx\n"
-                       "       movl %edx, 52(%esp)\n"
-                       /* replace saved flags with true return address. */
-                       "       movl %eax, 56(%esp)\n"
-                       "       popl %ebx\n" ""
-                       "       popl %ecx\n"
-                       "       popl %edx\n"
-                       "       popl %esi\n"
-                       "       popl %edi\n"
-                       "       popl %ebp\n"
-                       "       popl %eax\n"
-                       /* skip ds, es, fs, gs, orig_ax, and ip. Note: don't pop cs here*/
-                       "       addl $24, %esp\n"
-                       "       popf\n"
-                       "       ret\n");
-}
-
 void swap_kretprobe_trampoline(void);
+__asm(
+       ".global swap_kretprobe_trampoline      \n"
+       "swap_kretprobe_trampoline:             \n"
+       "pushf                                  \n"
+       SWAP_SAVE_REGS_STRING
+       "movl %esp, %eax                        \n"
+       "call trampoline_probe_handler_x86      \n"
+       /* move eflags to cs */
+       "movl 56(%esp), %edx                    \n"
+       "movl %edx, 52(%esp)                    \n"
+       /* replace saved flags with true return address. */
+       "movl %eax, 56(%esp)                    \n"
+       SWAP_RESTORE_REGS_STRING
+       "popf                                   \n"
+       "ret                                    \n"
+);
 
 /* insert a jmp code */
 static __always_inline void set_jmp_op (void *from, void *to)