aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/kprobes.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/kprobes.c')
-rw-r--r--arch/x86/kernel/kprobes.c20
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;