forked from Minki/linux
[PATCH] kprobes: Temporary disarming of reentrant probe for i386
This patch includes i386 architecture specific changes to support temporary disarming on reentrancy of probes. Signed-of-by: Prasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
parent
ea32c65cc2
commit
417c8da651
@ -37,12 +37,10 @@
|
|||||||
#include <asm/kdebug.h>
|
#include <asm/kdebug.h>
|
||||||
#include <asm/desc.h>
|
#include <asm/desc.h>
|
||||||
|
|
||||||
/* kprobe_status settings */
|
|
||||||
#define KPROBE_HIT_ACTIVE 0x00000001
|
|
||||||
#define KPROBE_HIT_SS 0x00000002
|
|
||||||
|
|
||||||
static struct kprobe *current_kprobe;
|
static struct kprobe *current_kprobe;
|
||||||
static unsigned long kprobe_status, kprobe_old_eflags, kprobe_saved_eflags;
|
static unsigned long kprobe_status, kprobe_old_eflags, kprobe_saved_eflags;
|
||||||
|
static struct kprobe *kprobe_prev;
|
||||||
|
static unsigned long kprobe_status_prev, kprobe_old_eflags_prev, kprobe_saved_eflags_prev;
|
||||||
static struct pt_regs jprobe_saved_regs;
|
static struct pt_regs jprobe_saved_regs;
|
||||||
static long *jprobe_saved_esp;
|
static long *jprobe_saved_esp;
|
||||||
/* copy of the kernel stack at the probe fire time */
|
/* copy of the kernel stack at the probe fire time */
|
||||||
@ -93,6 +91,31 @@ void arch_remove_kprobe(struct kprobe *p)
|
|||||||
{
|
{
|
||||||
}
|
}
|
||||||
|
|
||||||
|
static inline void save_previous_kprobe(void)
|
||||||
|
{
|
||||||
|
kprobe_prev = current_kprobe;
|
||||||
|
kprobe_status_prev = kprobe_status;
|
||||||
|
kprobe_old_eflags_prev = kprobe_old_eflags;
|
||||||
|
kprobe_saved_eflags_prev = kprobe_saved_eflags;
|
||||||
|
}
|
||||||
|
|
||||||
|
static inline void restore_previous_kprobe(void)
|
||||||
|
{
|
||||||
|
current_kprobe = kprobe_prev;
|
||||||
|
kprobe_status = kprobe_status_prev;
|
||||||
|
kprobe_old_eflags = kprobe_old_eflags_prev;
|
||||||
|
kprobe_saved_eflags = kprobe_saved_eflags_prev;
|
||||||
|
}
|
||||||
|
|
||||||
|
static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs)
|
||||||
|
{
|
||||||
|
current_kprobe = p;
|
||||||
|
kprobe_saved_eflags = kprobe_old_eflags
|
||||||
|
= (regs->eflags & (TF_MASK | IF_MASK));
|
||||||
|
if (is_IF_modifier(p->opcode))
|
||||||
|
kprobe_saved_eflags &= ~IF_MASK;
|
||||||
|
}
|
||||||
|
|
||||||
static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
|
static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
|
||||||
{
|
{
|
||||||
regs->eflags |= TF_MASK;
|
regs->eflags |= TF_MASK;
|
||||||
@ -184,9 +207,18 @@ static int kprobe_handler(struct pt_regs *regs)
|
|||||||
unlock_kprobes();
|
unlock_kprobes();
|
||||||
goto no_kprobe;
|
goto no_kprobe;
|
||||||
}
|
}
|
||||||
arch_disarm_kprobe(p);
|
/* We have reentered the kprobe_handler(), since
|
||||||
regs->eip = (unsigned long)p->addr;
|
* another probe was hit while within the handler.
|
||||||
ret = 1;
|
* We here save the original kprobes variables and
|
||||||
|
* just single step on the instruction of the new probe
|
||||||
|
* without calling any user handlers.
|
||||||
|
*/
|
||||||
|
save_previous_kprobe();
|
||||||
|
set_current_kprobe(p, regs);
|
||||||
|
p->nmissed++;
|
||||||
|
prepare_singlestep(p, regs);
|
||||||
|
kprobe_status = KPROBE_REENTER;
|
||||||
|
return 1;
|
||||||
} else {
|
} else {
|
||||||
p = current_kprobe;
|
p = current_kprobe;
|
||||||
if (p->break_handler && p->break_handler(p, regs)) {
|
if (p->break_handler && p->break_handler(p, regs)) {
|
||||||
@ -221,11 +253,7 @@ static int kprobe_handler(struct pt_regs *regs)
|
|||||||
}
|
}
|
||||||
|
|
||||||
kprobe_status = KPROBE_HIT_ACTIVE;
|
kprobe_status = KPROBE_HIT_ACTIVE;
|
||||||
current_kprobe = p;
|
set_current_kprobe(p, regs);
|
||||||
kprobe_saved_eflags = kprobe_old_eflags
|
|
||||||
= (regs->eflags & (TF_MASK | IF_MASK));
|
|
||||||
if (is_IF_modifier(p->opcode))
|
|
||||||
kprobe_saved_eflags &= ~IF_MASK;
|
|
||||||
|
|
||||||
if (p->pre_handler && p->pre_handler(p, regs))
|
if (p->pre_handler && p->pre_handler(p, regs))
|
||||||
/* handler has already set things up, so skip ss setup */
|
/* handler has already set things up, so skip ss setup */
|
||||||
@ -370,14 +398,22 @@ static inline int post_kprobe_handler(struct pt_regs *regs)
|
|||||||
if (!kprobe_running())
|
if (!kprobe_running())
|
||||||
return 0;
|
return 0;
|
||||||
|
|
||||||
if (current_kprobe->post_handler)
|
if ((kprobe_status != KPROBE_REENTER) && current_kprobe->post_handler) {
|
||||||
|
kprobe_status = KPROBE_HIT_SSDONE;
|
||||||
current_kprobe->post_handler(current_kprobe, regs, 0);
|
current_kprobe->post_handler(current_kprobe, regs, 0);
|
||||||
|
}
|
||||||
|
|
||||||
if (current_kprobe->post_handler != trampoline_post_handler)
|
if (current_kprobe->post_handler != trampoline_post_handler)
|
||||||
resume_execution(current_kprobe, regs);
|
resume_execution(current_kprobe, regs);
|
||||||
regs->eflags |= kprobe_saved_eflags;
|
regs->eflags |= kprobe_saved_eflags;
|
||||||
|
|
||||||
|
/*Restore back the original saved kprobes variables and continue. */
|
||||||
|
if (kprobe_status == KPROBE_REENTER) {
|
||||||
|
restore_previous_kprobe();
|
||||||
|
goto out;
|
||||||
|
}
|
||||||
unlock_kprobes();
|
unlock_kprobes();
|
||||||
|
out:
|
||||||
preempt_enable_no_resched();
|
preempt_enable_no_resched();
|
||||||
|
|
||||||
/*
|
/*
|
||||||
|
Loading…
Reference in New Issue
Block a user