arm: kprobes: make target areas writeable before writing
STRICT_MEMORY_RWX makes the kernel text section unwriteable.
This causes kprobes to fail when trying to arm or disarm probes.
Add calls to make the target area writeable during
the arming and disarming.
Change-Id: I8a37478defdb276278b72f5d6c684c661ca54cb1
Signed-off-by: Neil Leeder <nleeder@codeaurora.org>
diff --git a/arch/arm/kernel/kprobes.c b/arch/arm/kernel/kprobes.c
index 1656c87..cd5d2cc 100644
--- a/arch/arm/kernel/kprobes.c
+++ b/arch/arm/kernel/kprobes.c
@@ -27,6 +27,7 @@
#include <linux/stringify.h>
#include <asm/traps.h>
#include <asm/cacheflush.h>
+#include <asm/mmu_writeable.h>
#define MIN_STACK_SIZE(addr) \
min((unsigned long)MAX_STACK_SIZE, \
@@ -81,8 +82,14 @@
void __kprobes arch_arm_kprobe(struct kprobe *p)
{
+ unsigned long flags;
+
+ mem_text_writeable_spinlock(&flags);
+ mem_text_address_writeable((unsigned long)p->addr);
*p->addr = KPROBE_BREAKPOINT_INSTRUCTION;
flush_insns(p->addr, 1);
+ mem_text_address_restore();
+ mem_text_writeable_spinunlock(&flags);
}
/*
@@ -94,9 +101,14 @@
*/
int __kprobes __arch_disarm_kprobe(void *p)
{
+ unsigned long flags;
struct kprobe *kp = p;
+ mem_text_writeable_spinlock(&flags);
+ mem_text_address_writeable((unsigned long)kp->addr);
*kp->addr = kp->opcode;
flush_insns(kp->addr, 1);
+ mem_text_address_restore();
+ mem_text_writeable_spinunlock(&flags);
return 0;
}