From e2960317d4581689bf80dbad4d75e7a59f11a3f7 Mon Sep 17 00:00:00 2001 From: Jon Medhurst Date: Thu, 9 Jun 2011 14:05:51 +0100 Subject: 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 Acked-by: Nicolas Pitre --- arch/arm/kernel/kprobes.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/arm/kernel/kprobes.c') 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 */ -- cgit v1.2.3-18-g5258