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Diffstat (limited to 'arch/powerpc/kernel/kprobes.c')
-rw-r--r--arch/powerpc/kernel/kprobes.c65
1 files changed, 32 insertions, 33 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index c176c513566..2f72af82513 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -31,6 +31,8 @@
#include <linux/preempt.h>
#include <linux/module.h>
#include <linux/kdebug.h>
+#include <linux/slab.h>
+#include <asm/code-patching.h>
#include <asm/cacheflush.h>
#include <asm/sstep.h>
#include <asm/uaccess.h>
@@ -53,7 +55,8 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
ret = -EINVAL;
}
- /* insn must be on a special executable page on ppc64 */
+ /* insn must be on a special executable page on ppc64. This is
+ * not explicitly required on ppc32 (right now), but it doesn't hurt */
if (!ret) {
p->ainsn.insn = get_insn_slot();
if (!p->ainsn.insn)
@@ -88,14 +91,15 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
void __kprobes arch_remove_kprobe(struct kprobe *p)
{
- mutex_lock(&kprobe_mutex);
- free_insn_slot(p->ainsn.insn, 0);
- mutex_unlock(&kprobe_mutex);
+ if (p->ainsn.insn) {
+ free_insn_slot(p->ainsn.insn, 0);
+ p->ainsn.insn = NULL;
+ }
}
static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
{
- regs->msr |= MSR_SE;
+ enable_single_step(regs);
/*
* On powerpc we should single step on the original
@@ -127,7 +131,6 @@ static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
kcb->kprobe_saved_msr = regs->msr;
}
-/* Called with kretprobe_lock held */
void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
@@ -158,7 +161,8 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
kprobe_opcode_t insn = *p->ainsn.insn;
if (kcb->kprobe_status == KPROBE_HIT_SS &&
is_trap(insn)) {
- regs->msr &= ~MSR_SE;
+ /* Turn off 'trace' bits */
+ regs->msr &= ~MSR_SINGLESTEP;
regs->msr |= kcb->kprobe_saved_msr;
goto no_kprobe;
}
@@ -289,18 +293,17 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
{
struct kretprobe_instance *ri = NULL;
struct hlist_head *head, empty_rp;
- struct hlist_node *node, *tmp;
+ struct hlist_node *tmp;
unsigned long flags, orig_ret_address = 0;
unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline;
INIT_HLIST_HEAD(&empty_rp);
- spin_lock_irqsave(&kretprobe_lock, flags);
- head = kretprobe_inst_table_head(current);
+ kretprobe_hash_lock(current, &head, &flags);
/*
* It is possible to have multiple instances associated with a given
* task either because an multiple functions in the call path
- * have a return probe installed on them, and/or more then one return
+ * have a return probe installed on them, and/or more than one return
* return probe was registered for a target function.
*
* We can handle this because:
@@ -310,7 +313,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
* real return address, and all the rest will point to
* kretprobe_trampoline
*/
- hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
+ hlist_for_each_entry_safe(ri, tmp, head, hlist) {
if (ri->task != current)
/* another task is sharing our hash bucket */
continue;
@@ -334,10 +337,10 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
regs->nip = orig_ret_address;
reset_current_kprobe();
- spin_unlock_irqrestore(&kretprobe_lock, flags);
+ kretprobe_hash_unlock(current, &flags);
preempt_enable_no_resched();
- hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
+ hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
kfree(ri);
}
@@ -357,17 +360,6 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
* single-stepped a copy of the instruction. The address of this
* copy is p->ainsn.insn.
*/
-static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
-{
- int ret;
- unsigned int insn = *p->ainsn.insn;
-
- regs->nip = (unsigned long)p->addr;
- ret = emulate_step(regs, insn);
- if (ret == 0)
- regs->nip = (unsigned long)p->addr + 4;
-}
-
static int __kprobes post_kprobe_handler(struct pt_regs *regs)
{
struct kprobe *cur = kprobe_running();
@@ -376,12 +368,17 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs)
if (!cur)
return 0;
+ /* make sure we got here for instruction we have a kprobe on */
+ if (((unsigned long)cur->ainsn.insn + 4) != regs->nip)
+ return 0;
+
if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
kcb->kprobe_status = KPROBE_HIT_SSDONE;
cur->post_handler(cur, regs, 0);
}
- resume_execution(cur, regs);
+ /* Adjust nip to after the single-stepped instruction */
+ regs->nip = (unsigned long)cur->addr + 4;
regs->msr |= kcb->kprobe_saved_msr;
/*Restore back the original saved kprobes variables and continue. */
@@ -395,10 +392,10 @@ out:
/*
* if somebody else is singlestepping across a probe point, msr
- * will have SE set, in which case, continue the remaining processing
+ * will have DE/SE set, in which case, continue the remaining processing
* of do_debug, as if this is not a probe hit.
*/
- if (regs->msr & MSR_SE)
+ if (regs->msr & MSR_SINGLESTEP)
return 0;
return 1;
@@ -421,7 +418,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
* normal page fault.
*/
regs->nip = (unsigned long)cur->addr;
- regs->msr &= ~MSR_SE;
+ regs->msr &= ~MSR_SINGLESTEP; /* Turn off 'trace' bits */
regs->msr |= kcb->kprobe_saved_msr;
if (kcb->kprobe_status == KPROBE_REENTER)
restore_previous_kprobe(kcb);
@@ -433,7 +430,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
case KPROBE_HIT_SSDONE:
/*
* We increment the nmissed count for accounting,
- * we can also use npre/npostfault count for accouting
+ * we can also use npre/npostfault count for accounting
* these specific fault cases.
*/
kprobes_inc_nmissed_count(cur);
@@ -495,12 +492,10 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
return ret;
}
-#ifdef CONFIG_PPC64
unsigned long arch_deref_entry_point(void *entry)
{
- return (unsigned long)(((func_descr_t *)entry)->entry);
+ return ppc_global_function_entry(entry);
}
-#endif
int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
{
@@ -512,8 +507,12 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
/* setup return addr to the jprobe handler routine */
regs->nip = arch_deref_entry_point(jp->entry);
#ifdef CONFIG_PPC64
+#if defined(_CALL_ELF) && _CALL_ELF == 2
+ regs->gpr[12] = (unsigned long)jp->entry;
+#else
regs->gpr[2] = (unsigned long)(((func_descr_t *)jp->entry)->toc);
#endif
+#endif
return 1;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 02:03:18 +0000