#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/kprobes.h>
+#include <linux/module.h>
#include <asm/kdebug.h>
#include <asm/signal.h>
#include <asm/cacheflush.h>
+#include <asm/uaccess.h>
/* We do not have hardware single-stepping on sparc64.
* So we implement software single-stepping with breakpoint
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
int __kprobes arch_prepare_kprobe(struct kprobe *p)
-{
- return 0;
-}
-
-void __kprobes arch_copy_kprobe(struct kprobe *p)
{
p->ainsn.insn[0] = *p->addr;
p->ainsn.insn[1] = BREAKPOINT_INSTRUCTION_2;
p->opcode = *p->addr;
+ return 0;
}
void __kprobes arch_arm_kprobe(struct kprobe *p)
flushi(p->addr);
}
-void __kprobes arch_remove_kprobe(struct kprobe *p)
-{
-}
-
-static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
+static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
{
kcb->prev_kprobe.kp = kprobe_running();
kcb->prev_kprobe.status = kcb->kprobe_status;
kcb->prev_kprobe.orig_tstate_pil = kcb->kprobe_orig_tstate_pil;
}
-static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb)
+static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
{
__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
kcb->kprobe_status = kcb->prev_kprobe.status;
kcb->kprobe_orig_tstate_pil = kcb->prev_kprobe.orig_tstate_pil;
}
-static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
+static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
struct kprobe_ctlblk *kcb)
{
__get_cpu_var(current_kprobe) = p;
kcb->kprobe_orig_tstate_pil = (regs->tstate & TSTATE_PIL);
}
-static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs,
+static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs,
struct kprobe_ctlblk *kcb)
{
regs->tstate |= TSTATE_PIL;
*/
save_previous_kprobe(kcb);
set_current_kprobe(p, regs, kcb);
- p->nmissed++;
+ kprobes_inc_nmissed_count(p);
kcb->kprobe_status = KPROBE_REENTER;
prepare_singlestep(p, regs, kcb);
return 1;
} else {
+ if (*(u32 *)addr != BREAKPOINT_INSTRUCTION) {
+ /* The breakpoint instruction was removed by
+ * another cpu right after we hit, no further
+ * handling of this interrupt is appropriate
+ */
+ ret = 1;
+ goto no_kprobe;
+ }
p = __get_cpu_var(current_kprobe);
if (p->break_handler && p->break_handler(p, regs))
goto ss_probe;
kcb->kprobe_orig_tstate_pil);
}
-static inline int post_kprobe_handler(struct pt_regs *regs)
+static int __kprobes post_kprobe_handler(struct pt_regs *regs)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
return 1;
}
-static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+static int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ const struct exception_table_entry *entry;
+
+ switch(kcb->kprobe_status) {
+ case KPROBE_HIT_SS:
+ case KPROBE_REENTER:
+ /*
+ * We are here because the instruction being single
+ * stepped caused a page fault. We reset the current
+ * kprobe and the tpc points back to the probe address
+ * and allow the page fault handler to continue as a
+ * normal page fault.
+ */
+ regs->tpc = (unsigned long)cur->addr;
+ regs->tnpc = kcb->kprobe_orig_tnpc;
+ regs->tstate = ((regs->tstate & ~TSTATE_PIL) |
+ kcb->kprobe_orig_tstate_pil);
+ if (kcb->kprobe_status == KPROBE_REENTER)
+ restore_previous_kprobe(kcb);
+ else
+ reset_current_kprobe();
+ preempt_enable_no_resched();
+ break;
+ case KPROBE_HIT_ACTIVE:
+ case KPROBE_HIT_SSDONE:
+ /*
+ * We increment the nmissed count for accounting,
+ * we can also use npre/npostfault count for accouting
+ * these specific fault cases.
+ */
+ kprobes_inc_nmissed_count(cur);
+
+ /*
+ * We come here because instructions in the pre/post
+ * handler caused the page_fault, this could happen
+ * if handler tries to access user space by
+ * copy_from_user(), get_user() etc. Let the
+ * user-specified handler try to fix it first.
+ */
+ if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
+ return 1;
- if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
- return 1;
+ /*
+ * In case the user-specified fault handler returned
+ * zero, try to fix up.
+ */
- if (kcb->kprobe_status & KPROBE_HIT_SS) {
- resume_execution(cur, regs, kcb);
+ entry = search_exception_tables(regs->tpc);
+ if (entry) {
+ regs->tpc = entry->fixup;
+ regs->tnpc = regs->tpc + 4;
+ return 1;
+ }
- reset_current_kprobe();
- preempt_enable_no_resched();
+ /*
+ * fixup_exception() could not handle it,
+ * Let do_page_fault() fix it.
+ */
+ break;
+ default:
+ break;
}
+
return 0;
}
struct die_args *args = (struct die_args *)data;
int ret = NOTIFY_DONE;
+ if (args->regs && user_mode(args->regs))
+ return ret;
+
switch (val) {
case DIE_DEBUG:
if (kprobe_handler(args->regs))
git.openpandora.org / pandora-kernel.git / blobdiff