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| author |   Jon Medhurst <tixy@yxit.co.uk> | 2011-04-07 13:25:16 +0100 |
|---|---|---|
| committer |   Nicolas Pitre <nicolas.pitre@linaro.org> | 2011-04-28 23:40:55 -0400 |
| commit | c412aba2a1243192a4d53736805a96bdda915608 (patch) | |
| tree | f04010b8c82fcc4ef9934144dd8eb8cbf6f8ad1c /arch/arm/kernel | |
| parent | ARM: kprobes: Reject probing MRS instructions which read SPSR (diff) | |
| download | linux-dev-c412aba2a1243192a4d53736805a96bdda915608.tar.xz linux-dev-c412aba2a1243192a4d53736805a96bdda915608.zip | |
ARM: kprobes: Fix emulation of MRS instruction
The MRS instruction should set mode and interrupt bits in the read value
so it is simpler to use a new simulation routine (simulate_mrs) rather
than some modified emulation.
prep_emulate_rd12 is now unused and removed.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Diffstat (limited to 'arch/arm/kernel')
| -rw-r--r-- | arch/arm/kernel/kprobes-decode.c | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c index e5bc576ba3fb..4ab83f4c47cf 100644 --- a/arch/arm/kernel/kprobes-decode.c +++ b/arch/arm/kernel/kprobes-decode.c @@ -451,6 +451,14 @@ static void __kprobes simulate_blx2bx(struct kprobe *p, struct pt_regs *regs) regs->ARM_cpsr |= PSR_T_BIT; } +static void __kprobes simulate_mrs(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 12) & 0xf; + unsigned long mask = 0xf8ff03df; /* Mask out execution state */ + regs->uregs[rd] = regs->ARM_cpsr & mask; +} + static void __kprobes simulate_ldm1stm1(struct kprobe *p, struct pt_regs *regs) { kprobe_opcode_t insn = p->opcode; @@ -896,15 +904,6 @@ prep_emulate_rd12rm0(kprobe_opcode_t insn, struct arch_specific_insn *asi) } static enum kprobe_insn __kprobes -prep_emulate_rd12(kprobe_opcode_t insn, struct arch_specific_insn *asi) -{ - insn &= 0xffff0fff; /* Rd = r0 */ - asi->insn[0] = insn; - asi->insn_handler = emulate_rd12; - return INSN_GOOD; -} - -static enum kprobe_insn __kprobes prep_emulate_rd12rn16rm0_wflags(kprobe_opcode_t insn, struct arch_specific_insn *asi) { @@ -1035,8 +1034,10 @@ space_cccc_000x(kprobe_opcode_t insn, struct arch_specific_insn *asi) return INSN_REJECTED; /* MRS cpsr : cccc 0001 0000 xxxx xxxx xxxx 0000 xxxx */ - if ((insn & 0x0ff000f0) == 0x01000000) - return prep_emulate_rd12(insn, asi); + if ((insn & 0x0ff000f0) == 0x01000000) { + asi->insn_handler = simulate_mrs; + return INSN_GOOD_NO_SLOT; + } /* SMLALxy : cccc 0001 0100 xxxx xxxx xxxx 1xx0 xxxx */ if ((insn & 0x0ff00090) == 0x01400080) |