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authorJon Medhurst <tixy@yxit.co.uk>2011-06-09 14:05:51 +0100
committerTixy <tixy@medhuaa1.miniserver.com>2011-07-13 17:32:42 +0000
commite2960317d4581689bf80dbad4d75e7a59f11a3f7 (patch)
tree1a80fc69624bd87d1e2393c3a67ce15dc1c17daf /arch/arm/kernel
parentc6a7d97d57ef41477a85f4c0f48ea5243132ee1f (diff)
ARM: kprobes: Extend arch_specific_insn to add pointer to emulated instruction
When we come to emulating Thumb instructions then, to interwork correctly, the code on in the instruction slot must be invoked with a function pointer which has the least significant bit set. Rather that set this by hand in every Thumb emulation function we will add a new field for this purpose to arch_specific_insn, called insn_fn. This also enables us to seamlessly share emulation functions between ARM and Thumb code. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/kprobes.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm/kernel/kprobes.c b/arch/arm/kernel/kprobes.c
index 77b7c697480..129c1163248 100644
--- a/arch/arm/kernel/kprobes.c
+++ b/arch/arm/kernel/kprobes.c
@@ -51,6 +51,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
kprobe_opcode_t insn;
kprobe_opcode_t tmp_insn[MAX_INSN_SIZE];
unsigned long addr = (unsigned long)p->addr;
+ bool thumb;
kprobe_decode_insn_t *decode_insn;
int is;
@@ -58,6 +59,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
return -EINVAL;
#ifdef CONFIG_THUMB2_KERNEL
+ thumb = true;
addr &= ~1; /* Bit 0 would normally be set to indicate Thumb code */
insn = ((u16 *)addr)[0];
if (is_wide_instruction(insn)) {
@@ -67,6 +69,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
} else
decode_insn = thumb16_kprobe_decode_insn;
#else /* !CONFIG_THUMB2_KERNEL */
+ thumb = false;
if (addr & 0x3)
return -EINVAL;
insn = *p->addr;
@@ -88,6 +91,8 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
p->ainsn.insn[is] = tmp_insn[is];
flush_insns(p->ainsn.insn,
sizeof(p->ainsn.insn[0]) * MAX_INSN_SIZE);
+ p->ainsn.insn_fn = (kprobe_insn_fn_t *)
+ ((uintptr_t)p->ainsn.insn | thumb);
break;
case INSN_GOOD_NO_SLOT: /* instruction doesn't need insn slot */