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| author | Jon Medhurst <tixy@yxit.co.uk> | 2011-04-18 08:53:57 +0100 |
|---|---|---|
| committer | Nicolas Pitre <nicolas.pitre@linaro.org> | 2011-04-28 23:40:59 -0400 |
| commit | 41713d1396312a027ec02abc4767041627c178ef (patch) | |
| tree | 778fedcc66cf4e15ca1e0eeb8502715bd84d021d /arch/arm | |
| parent | f0aeb8bff0fe9de50e1e4093ef86ff8f17a9b1b0 (diff) | |
| download | lwn-41713d1396312a027ec02abc4767041627c178ef.tar.gz lwn-41713d1396312a027ec02abc4767041627c178ef.zip | |
ARM: kprobes: Fix emulation of PLD instructions
The PLD instructions wasn't being decoded correctly and the emulation
code wasn't adjusting PC correctly.
As the PLD instruction is only a performance hint we emulate it as a
simple nop, and we can broaden the instruction decoding to take into
account newer PLI and PLDW instructions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/kernel/kprobes-decode.c | 21 |
1 files changed, 8 insertions, 13 deletions
diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c index b81fbfb33151..bddf8d0f3dc1 100644 --- a/arch/arm/kernel/kprobes-decode.c +++ b/arch/arm/kernel/kprobes-decode.c @@ -657,14 +657,8 @@ static void __kprobes emulate_none(struct kprobe *p, struct pt_regs *regs) insnslot_0arg_rflags(regs->ARM_cpsr, i_fn); } -static void __kprobes emulate_rn16(struct kprobe *p, struct pt_regs *regs) +static void __kprobes emulate_nop(struct kprobe *p, struct pt_regs *regs) { - insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; - kprobe_opcode_t insn = p->opcode; - int rn = (insn >> 16) & 0xf; - long rnv = regs->uregs[rn]; - - insnslot_1arg_rflags(rnv, regs->ARM_cpsr, i_fn); } static void __kprobes emulate_rd12rm0(struct kprobe *p, struct pt_regs *regs) @@ -941,12 +935,13 @@ space_1111(kprobe_opcode_t insn, struct arch_specific_insn *asi) (insn & 0xfe5f0f00) == 0xf84d0500) return INSN_REJECTED; - /* PLD : 1111 01x1 x101 xxxx xxxx xxxx xxxx xxxx : */ - if ((insn & 0xfd700000) == 0xf4500000) { - insn &= 0xfff0ffff; /* Rn = r0 */ - asi->insn[0] = insn; - asi->insn_handler = emulate_rn16; - return INSN_GOOD; + /* memory hint : 1111 0100 x001 xxxx xxxx xxxx xxxx xxxx : */ + /* PLDI : 1111 0100 x101 xxxx xxxx xxxx xxxx xxxx : */ + /* PLDW : 1111 0101 x001 xxxx xxxx xxxx xxxx xxxx : */ + /* PLD : 1111 0101 x101 xxxx xxxx xxxx xxxx xxxx : */ + if ((insn & 0xfe300000) == 0xf4100000) { + asi->insn_handler = emulate_nop; + return INSN_GOOD_NO_SLOT; } /* BLX(1) : 1111 101x xxxx xxxx xxxx xxxx xxxx xxxx : */ |