1 files changed, 12 insertions, 8 deletions

diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index e948b28a5a9a..7b5169d2b000 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -193,6 +193,9 @@ static int __kprobes can_boost(kprobe_opcode_t *opcodes)
         kprobe_opcode_t opcode;
         kprobe_opcode_t *orig_opcodes = opcodes;
 
+        if (search_exception_tables((unsigned long)opcodes))
+                return 0;       /* Page fault may occur on this address. */
+
 retry:
         if (opcodes - orig_opcodes > MAX_INSN_SIZE - 1)
                 return 0;
@@ -635,13 +638,13 @@ static void __used __kprobes kretprobe_trampoline_holder(void)
 #else
                         "       pushf\n"
                         /*
-                         * Skip cs, ip, orig_ax.
+                         * Skip cs, ip, orig_ax and gs.
                          * trampoline_handler() will plug in these values
                          */
-                        "       subl $12, %esp\n"
+                        "       subl $16, %esp\n"
                         "       pushl %fs\n"
-                        "       pushl %ds\n"
                         "       pushl %es\n"
+                        "       pushl %ds\n"
                         "       pushl %eax\n"
                         "       pushl %ebp\n"
                         "       pushl %edi\n"
@@ -652,10 +655,10 @@ static void __used __kprobes kretprobe_trampoline_holder(void)
                         "       movl %esp, %eax\n"
                         "       call trampoline_handler\n"
                         /* Move flags to cs */
-                        "       movl 52(%esp), %edx\n"
-                        "       movl %edx, 48(%esp)\n"
+                        "       movl 56(%esp), %edx\n"
+                        "       movl %edx, 52(%esp)\n"
                         /* Replace saved flags with true return address. */
-                        "       movl %eax, 52(%esp)\n"
+                        "       movl %eax, 56(%esp)\n"
                         "       popl %ebx\n"
                         "       popl %ecx\n"
                         "       popl %edx\n"
@@ -663,8 +666,8 @@ static void __used __kprobes kretprobe_trampoline_holder(void)
                         "       popl %edi\n"
                         "       popl %ebp\n"
                         "       popl %eax\n"
-                        /* Skip ip, orig_ax, es, ds, fs */
-                        "       addl $20, %esp\n"
+                        /* Skip ds, es, fs, gs, orig_ax and ip */
+                        "       addl $24, %esp\n"
                         "       popf\n"
 #endif
                         "       ret\n");
@@ -688,6 +691,7 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
         regs->cs = __KERNEL_CS;
 #else
         regs->cs = __KERNEL_CS | get_kernel_rpl();
+        regs->gs = 0;
 #endif
         regs->ip = trampoline_address;
         regs->orig_ax = ~0UL;