From 3c48fbb1478f47a95d18a56ff2662b40cb236152 Mon Sep 17 00:00:00 2001 From: Jon Medhurst Date: Sat, 11 Jun 2011 13:10:49 +0100 Subject: [PATCH] ARM: kprobes: Add new versions of emulate_ldr() and emulate_str() These use the register calling conventions required by the new decoding table framework for calling simulated instructions. We rename the old versions of these functions to *_old for now. Signed-off-by: Jon Medhurst Acked-by: Nicolas Pitre --- arch/arm/kernel/kprobes-arm.c | 63 +++++++++++++++++++++++++++++++++-- 1 file changed, 60 insertions(+), 3 deletions(-) diff --git a/arch/arm/kernel/kprobes-arm.c b/arch/arm/kernel/kprobes-arm.c index bb38ae3601c..d252e7821fc 100644 --- a/arch/arm/kernel/kprobes-arm.c +++ b/arch/arm/kernel/kprobes-arm.c @@ -502,7 +502,7 @@ static void __kprobes emulate_strd(struct kprobe *p, struct pt_regs *regs) regs->uregs[rn] = rnv_wb; } -static void __kprobes emulate_ldr(struct kprobe *p, struct pt_regs *regs) +static void __kprobes emulate_ldr_old(struct kprobe *p, struct pt_regs *regs) { insn_llret_3arg_fn_t *i_fn = (insn_llret_3arg_fn_t *)&p->ainsn.insn[0]; kprobe_opcode_t insn = p->opcode; @@ -535,7 +535,7 @@ static void __kprobes emulate_ldr(struct kprobe *p, struct pt_regs *regs) regs->uregs[rd] = rdv; } -static void __kprobes emulate_str(struct kprobe *p, struct pt_regs *regs) +static void __kprobes emulate_str_old(struct kprobe *p, struct pt_regs *regs) { insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0]; kprobe_opcode_t insn = p->opcode; @@ -795,7 +795,7 @@ prep_emulate_ldr_str(kprobe_opcode_t insn, struct arch_specific_insn *asi) insn |= 2; /* Rm = r2 */ } asi->insn[0] = insn; - asi->insn_handler = (insn & (1 << 20)) ? emulate_ldr : emulate_str; + asi->insn_handler = (insn & (1 << 20)) ? emulate_ldr_old : emulate_str_old; return INSN_GOOD; } @@ -922,6 +922,63 @@ emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs) regs->uregs[rn] = rnv; } +static void __kprobes +emulate_ldr(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + unsigned long pc = (unsigned long)p->addr + 8; + int rt = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + + register unsigned long rtv asm("r0"); + register unsigned long rnv asm("r2") = (rn == 15) ? pc + : regs->uregs[rn]; + register unsigned long rmv asm("r3") = regs->uregs[rm]; + + __asm__ __volatile__ ( + BLX("%[fn]") + : "=r" (rtv), "=r" (rnv) + : "1" (rnv), "r" (rmv), [fn] "r" (p->ainsn.insn_fn) + : "lr", "memory", "cc" + ); + + if (rt == 15) + load_write_pc(rtv, regs); + else + regs->uregs[rt] = rtv; + + if (is_writeback(insn)) + regs->uregs[rn] = rnv; +} + +static void __kprobes +emulate_str(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + unsigned long rtpc = (unsigned long)p->addr + str_pc_offset; + unsigned long rnpc = (unsigned long)p->addr + 8; + int rt = (insn >> 12) & 0xf; + int rn = (insn >> 16) & 0xf; + int rm = insn & 0xf; + + register unsigned long rtv asm("r0") = (rt == 15) ? rtpc + : regs->uregs[rt]; + register unsigned long rnv asm("r2") = (rn == 15) ? rnpc + : regs->uregs[rn]; + register unsigned long rmv asm("r3") = regs->uregs[rm]; + + __asm__ __volatile__ ( + BLX("%[fn]") + : "=r" (rnv) + : "r" (rtv), "0" (rnv), "r" (rmv), [fn] "r" (p->ainsn.insn_fn) + : "lr", "memory", "cc" + ); + + if (is_writeback(insn)) + regs->uregs[rn] = rnv; +} + static void __kprobes emulate_rd12rn16rm0rs8_rwflags(struct kprobe *p, struct pt_regs *regs) { -- 2.39.5