diff options
Diffstat (limited to 'arch/i386/kernel/kprobes.c')
| -rw-r--r-- | arch/i386/kernel/kprobes.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c index d98e44b16fe2..fc79e1e859c4 100644 --- a/arch/i386/kernel/kprobes.c +++ b/arch/i386/kernel/kprobes.c @@ -361,8 +361,11 @@ no_kprobe: asm volatile ( ".global kretprobe_trampoline\n" "kretprobe_trampoline: \n" " pushf\n" - /* skip cs, eip, orig_eax, es, ds */ - " subl $20, %esp\n" + /* skip cs, eip, orig_eax */ + " subl $12, %esp\n" + " pushl %gs\n" + " pushl %ds\n" + " pushl %es\n" " pushl %eax\n" " pushl %ebp\n" " pushl %edi\n" @@ -373,10 +376,10 @@ no_kprobe: " movl %esp, %eax\n" " call trampoline_handler\n" /* move eflags to cs */ - " movl 48(%esp), %edx\n" - " movl %edx, 44(%esp)\n" + " movl 52(%esp), %edx\n" + " movl %edx, 48(%esp)\n" /* save true return address on eflags */ - " movl %eax, 48(%esp)\n" + " movl %eax, 52(%esp)\n" " popl %ebx\n" " popl %ecx\n" " popl %edx\n" @@ -384,8 +387,8 @@ no_kprobe: " popl %edi\n" " popl %ebp\n" " popl %eax\n" - /* skip eip, orig_eax, es, ds */ - " addl $16, %esp\n" + /* skip eip, orig_eax, es, ds, gs */ + " addl $20, %esp\n" " popf\n" " ret\n"); } @@ -404,6 +407,10 @@ fastcall void *__kprobes trampoline_handler(struct pt_regs *regs) INIT_HLIST_HEAD(&empty_rp); spin_lock_irqsave(&kretprobe_lock, flags); head = kretprobe_inst_table_head(current); + /* fixup registers */ + regs->xcs = __KERNEL_CS; + regs->eip = trampoline_address; + regs->orig_eax = 0xffffffff; /* * It is possible to have multiple instances associated with a given @@ -425,6 +432,7 @@ fastcall void *__kprobes trampoline_handler(struct pt_regs *regs) if (ri->rp && ri->rp->handler){ __get_cpu_var(current_kprobe) = &ri->rp->kp; + get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE; ri->rp->handler(ri, regs); __get_cpu_var(current_kprobe) = NULL; } |