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Diffstat (limited to 'arch/x86/kernel/kprobes/ftrace.c')
-rw-r--r--arch/x86/kernel/kprobes/ftrace.c49
1 files changed, 13 insertions, 36 deletions
diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c
index 8dc0161cec8f..ef819e19650b 100644
--- a/arch/x86/kernel/kprobes/ftrace.c
+++ b/arch/x86/kernel/kprobes/ftrace.c
@@ -25,36 +25,6 @@
#include "common.h"
-static nokprobe_inline
-void __skip_singlestep(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb, unsigned long orig_ip)
-{
- /*
- * Emulate singlestep (and also recover regs->ip)
- * as if there is a 5byte nop
- */
- regs->ip = (unsigned long)p->addr + MCOUNT_INSN_SIZE;
- if (unlikely(p->post_handler)) {
- kcb->kprobe_status = KPROBE_HIT_SSDONE;
- p->post_handler(p, regs, 0);
- }
- __this_cpu_write(current_kprobe, NULL);
- if (orig_ip)
- regs->ip = orig_ip;
-}
-
-int skip_singlestep(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb)
-{
- if (kprobe_ftrace(p)) {
- __skip_singlestep(p, regs, kcb, 0);
- preempt_enable_no_resched();
- return 1;
- }
- return 0;
-}
-NOKPROBE_SYMBOL(skip_singlestep);
-
/* Ftrace callback handler for kprobes -- called under preepmt disabed */
void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *ops, struct pt_regs *regs)
@@ -75,18 +45,25 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
/* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */
regs->ip = ip + sizeof(kprobe_opcode_t);
- /* To emulate trap based kprobes, preempt_disable here */
- preempt_disable();
__this_cpu_write(current_kprobe, p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
if (!p->pre_handler || !p->pre_handler(p, regs)) {
- __skip_singlestep(p, regs, kcb, orig_ip);
- preempt_enable_no_resched();
+ /*
+ * Emulate singlestep (and also recover regs->ip)
+ * as if there is a 5byte nop
+ */
+ regs->ip = (unsigned long)p->addr + MCOUNT_INSN_SIZE;
+ if (unlikely(p->post_handler)) {
+ kcb->kprobe_status = KPROBE_HIT_SSDONE;
+ p->post_handler(p, regs, 0);
+ }
+ regs->ip = orig_ip;
}
/*
- * If pre_handler returns !0, it sets regs->ip and
- * resets current kprobe, and keep preempt count +1.
+ * If pre_handler returns !0, it changes regs->ip. We have to
+ * skip emulating post_handler.
*/
+ __this_cpu_write(current_kprobe, NULL);
}
}
NOKPROBE_SYMBOL(kprobe_ftrace_handler);