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-rw-r--r--arch/arm/kernel/kprobes.c8
-rw-r--r--arch/arm/kernel/traps.c12
-rw-r--r--include/asm-arm/kprobes.h7
3 files changed, 20 insertions, 7 deletions
diff --git a/arch/arm/kernel/kprobes.c b/arch/arm/kernel/kprobes.c
index 450ee2cbfe1..a22a98c43ca 100644
--- a/arch/arm/kernel/kprobes.c
+++ b/arch/arm/kernel/kprobes.c
@@ -26,12 +26,6 @@
#include <asm/traps.h>
#include <asm/cacheflush.h>
-/*
- * This undefined instruction must be unique and
- * reserved solely for kprobes' use.
- */
-#define KPROBE_BREAKPOINT_INSTRUCTION 0xe7f001f8
-
#define MIN_STACK_SIZE(addr) \
min((unsigned long)MAX_STACK_SIZE, \
(unsigned long)current_thread_info() + THREAD_START_SP - (addr))
@@ -206,7 +200,7 @@ void __kprobes kprobe_handler(struct pt_regs *regs)
}
}
-static int kprobe_trap_handler(struct pt_regs *regs, unsigned int instr)
+int kprobe_trap_handler(struct pt_regs *regs, unsigned int instr)
{
kprobe_handler(regs);
return 0;
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 65bb762b2d8..5595fdd75e8 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -19,6 +19,7 @@
#include <linux/kallsyms.h>
#include <linux/delay.h>
#include <linux/init.h>
+#include <linux/kprobes.h>
#include <asm/atomic.h>
#include <asm/cacheflush.h>
@@ -313,6 +314,17 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
get_user(instr, (u32 __user *)pc);
}
+#ifdef CONFIG_KPROBES
+ /*
+ * It is possible to have recursive kprobes, so we can't call
+ * the kprobe trap handler with the undef_lock held.
+ */
+ if (instr == KPROBE_BREAKPOINT_INSTRUCTION && !user_mode(regs)) {
+ kprobe_trap_handler(regs, instr);
+ return;
+ }
+#endif
+
spin_lock_irqsave(&undef_lock, flags);
list_for_each_entry(hook, &undef_hook, node) {
if ((instr & hook->instr_mask) == hook->instr_val &&
diff --git a/include/asm-arm/kprobes.h b/include/asm-arm/kprobes.h
index 273f37413ee..4e7bd32288a 100644
--- a/include/asm-arm/kprobes.h
+++ b/include/asm-arm/kprobes.h
@@ -25,6 +25,12 @@
#define MAX_INSN_SIZE 2
#define MAX_STACK_SIZE 64 /* 32 would probably be OK */
+/*
+ * This undefined instruction must be unique and
+ * reserved solely for kprobes' use.
+ */
+#define KPROBE_BREAKPOINT_INSTRUCTION 0xe7f001f8
+
#define regs_return_value(regs) ((regs)->ARM_r0)
#define flush_insn_slot(p) do { } while (0)
#define kretprobe_blacklist_size 0
@@ -55,6 +61,7 @@ struct kprobe_ctlblk {
void arch_remove_kprobe(struct kprobe *);
+int kprobe_trap_handler(struct pt_regs *regs, unsigned int instr);
int kprobe_fault_handler(struct pt_regs *regs, unsigned int fsr);
int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data);