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x86: jprobe bugfix 

jprobe for x86-64 may cause kernel page fault when the jprobe_return()
is called from incorrect function.

- Use jprobe_saved_regs instead getting it from stack.
  (Especially on x86-64, it may get incorrect data, because
   pt_regs can not be get by using container_of(rsp))
- Change the type of stack pointer to unsigned long *.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Masami Hiramatsu 2007-12-18 18:05:58 +01:00 committed by Ingo Molnar
parent b4be625852
commit 29b6cd794e
4 changed files with 5 additions and 9 deletions
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4
arch/x86/kernel/kprobes_32.c
View File

@ -727,9 +727,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) {
if (&regs->esp != kcb->jprobe_saved_esp) {
struct pt_regs *saved_regs =
container_of(kcb->jprobe_saved_esp,
struct pt_regs, esp);
struct pt_regs *saved_regs = &kcb->jprobe_saved_regs;
printk("current esp %p does not match saved esp %p\n",
&regs->esp, kcb->jprobe_saved_esp);
printk("Saved registers for jprobe %p\n", jp);

6
arch/x86/kernel/kprobes_64.c
View File

@ -716,10 +716,8 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
struct jprobe *jp = container_of(p, struct jprobe, kp);
if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) {
if ((long *)regs->rsp != kcb->jprobe_saved_rsp) {
struct pt_regs *saved_regs =
container_of(kcb->jprobe_saved_rsp,
struct pt_regs, rsp);
if ((unsigned long *)regs->rsp != kcb->jprobe_saved_rsp) {
struct pt_regs *saved_regs = &kcb->jprobe_saved_regs;
printk("current rsp %p does not match saved rsp %p\n",
(long *)regs->rsp, kcb->jprobe_saved_rsp);
printk("Saved registers for jprobe %p\n", jp);

2
include/asm-x86/kprobes_32.h
View File

@ -73,7 +73,7 @@ struct kprobe_ctlblk {
unsigned long kprobe_status;
unsigned long kprobe_old_eflags;
unsigned long kprobe_saved_eflags;
long *jprobe_saved_esp;
unsigned long *jprobe_saved_esp;
struct pt_regs jprobe_saved_regs;
kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
struct prev_kprobe prev_kprobe;

2
include/asm-x86/kprobes_64.h
View File

@ -66,7 +66,7 @@ struct kprobe_ctlblk {
unsigned long kprobe_status;
unsigned long kprobe_old_rflags;
unsigned long kprobe_saved_rflags;
long *jprobe_saved_rsp;
unsigned long *jprobe_saved_rsp;
struct pt_regs jprobe_saved_regs;
kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
struct prev_kprobe prev_kprobe;