From mboxrd@z Thu Jan 1 00:00:00 1970 From: tixy@linaro.org (Jon Medhurst (Tixy)) Date: Mon, 29 Jul 2013 09:01:41 +0100 Subject: [PATCH 1/4] ARM: kprobes: fix instruction fetch order with In-Reply-To: <1374786537-10726-2-git-send-email-ben.dooks@codethink.co.uk> References: <1374786537-10726-1-git-send-email-ben.dooks@codethink.co.uk> <1374786537-10726-2-git-send-email-ben.dooks@codethink.co.uk> Message-ID: <1375084901.3521.3.camel@linaro1.home> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 2013-07-25 at 22:08 +0100, Ben Dooks wrote: > If we are running BE8, the data and instruction endian-ness do not > match, so use to correctly translate memory accesses > into ARM instructions. > > Signed-off-by: Ben Dooks y > --- > arch/arm/kernel/kprobes-common.c | 14 ++++++++------ > arch/arm/kernel/kprobes.c | 9 +++++---- > 2 files changed, 13 insertions(+), 10 deletions(-) > > diff --git a/arch/arm/kernel/kprobes-common.c b/arch/arm/kernel/kprobes-common.c > index 18a7628..c0b202e 100644 > --- a/arch/arm/kernel/kprobes-common.c > +++ b/arch/arm/kernel/kprobes-common.c > @@ -14,6 +14,7 @@ > #include > #include > #include > +#include > > #include "kprobes.h" > > @@ -305,7 +306,8 @@ kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi) > > if (handler) { > /* We can emulate the instruction in (possibly) modified form */ > - asi->insn[0] = (insn & 0xfff00000) | (rn << 16) | reglist; > + asi->insn[0] = __opcode_to_mem_arm((insn & 0xfff00000) | > + (rn << 16) | reglist); > asi->insn_handler = handler; > return INSN_GOOD; > } > @@ -338,9 +340,9 @@ prepare_emulated_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi, > thumb_insn[2] = 0x4770; /* Thumb bx lr */ The line above and the one before it not in this diff also need fixing by changing to __opcode_to_mem_thumb16(0x4770). > return insn; > } > - asi->insn[1] = 0xe12fff1e; /* ARM bx lr */ > + asi->insn[1] = __opcode_to_mem_arm(0xe12fff1e); /* ARM bx lr */ > #else > - asi->insn[1] = 0xe1a0f00e; /* mov pc, lr */ > + asi->insn[1] = __opcode_to_mem_arm(0xe1a0f00e); /* mov pc, lr */ > #endif > /* Make an ARM instruction unconditional */ > if (insn < 0xe0000000) > @@ -360,12 +362,12 @@ set_emulated_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi, > if (thumb) { > u16 *ip = (u16 *)asi->insn; > if (is_wide_instruction(insn)) > - *ip++ = insn >> 16; > - *ip++ = insn; > + *ip++ = ___asm_opcode_to_mem_thumb16(insn >> 16); > + *ip++ = ___asm_opcode_to_mem_thumb16(insn); Should these two ___asm_opcode_thumb32_compose() not be __opcode_thumb32_compose() ? > return; > } > #endif > - asi->insn[0] = insn; > + asi->insn[0] = __opcode_to_mem_arm(insn); > } > > /* > diff --git a/arch/arm/kernel/kprobes.c b/arch/arm/kernel/kprobes.c > index 170e9f3..3775af1 100644 > --- a/arch/arm/kernel/kprobes.c > +++ b/arch/arm/kernel/kprobes.c > @@ -26,6 +26,7 @@ > #include > #include > #include > +#include > #include > > #include "kprobes.h" > @@ -62,10 +63,10 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) > #ifdef CONFIG_THUMB2_KERNEL > thumb = true; > addr &= ~1; /* Bit 0 would normally be set to indicate Thumb code */ > - insn = ((u16 *)addr)[0]; > + insn = __mem_to_opcode_thumb16(((u16 *)addr)[0]); > if (is_wide_instruction(insn)) { > - insn <<= 16; > - insn |= ((u16 *)addr)[1]; > + u16 inst2 = __mem_to_opcode_thumb16(((u16 *)addr)[1]); > + insn = ___asm_opcode_thumb32_compose(insn, inst2); Again, __opcode_thumb32_compose instead of ___asm_opcode_thumb32_compose > decode_insn = thumb32_kprobe_decode_insn; > } else > decode_insn = thumb16_kprobe_decode_insn; > @@ -73,7 +74,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) > thumb = false; > if (addr & 0x3) > return -EINVAL; > - insn = *p->addr; > + insn = __mem_to_opcode_arm(*p->addr); > decode_insn = arm_kprobe_decode_insn; > #endif > -- Tixy