From 7848786a7a198dd5e097330ad0cbfdf155a25499 Mon Sep 17 00:00:00 2001 From: Jon Medhurst Date: Sun, 3 Jul 2011 14:40:26 +0100 Subject: [PATCH] ARM: kprobes: Decode 32-bit Thumb data-processing (plain binary immediate) instructions Signed-off-by: Jon Medhurst Acked-by: Nicolas Pitre --- arch/arm/kernel/kprobes-thumb.c | 95 +++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) diff --git a/arch/arm/kernel/kprobes-thumb.c b/arch/arm/kernel/kprobes-thumb.c index cf834484fb58..1fbeba8093f1 100644 --- a/arch/arm/kernel/kprobes-thumb.c +++ b/arch/arm/kernel/kprobes-thumb.c @@ -124,6 +124,46 @@ t32_emulate_rd8rn16rm0_rwflags(struct kprobe *p, struct pt_regs *regs) regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK); } +static void __kprobes +t32_emulate_rd8pc16_noflags(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + unsigned long pc = thumb_probe_pc(p); + int rd = (insn >> 8) & 0xf; + + register unsigned long rdv asm("r1") = regs->uregs[rd]; + register unsigned long rnv asm("r2") = pc & ~3; + + __asm__ __volatile__ ( + "blx %[fn]" + : "=r" (rdv) + : "0" (rdv), "r" (rnv), [fn] "r" (p->ainsn.insn_fn) + : "lr", "memory", "cc" + ); + + regs->uregs[rd] = rdv; +} + +static void __kprobes +t32_emulate_rd8rn16_noflags(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + int rd = (insn >> 8) & 0xf; + int rn = (insn >> 16) & 0xf; + + register unsigned long rdv asm("r1") = regs->uregs[rd]; + register unsigned long rnv asm("r2") = regs->uregs[rn]; + + __asm__ __volatile__ ( + "blx %[fn]" + : "=r" (rdv) + : "0" (rdv), "r" (rnv), [fn] "r" (p->ainsn.insn_fn) + : "lr", "memory", "cc" + ); + + regs->uregs[rd] = rdv; +} + static const union decode_item t32_table_1110_100x_x0xx[] = { /* Load/store multiple instructions */ @@ -293,6 +333,55 @@ static const union decode_item t32_table_1111_0x0x___0[] = { DECODE_END }; +static const union decode_item t32_table_1111_0x1x___0[] = { + /* Data-processing (plain binary immediate) */ + + /* ADDW Rd, PC, #imm 1111 0x10 0000 1111 0xxx xxxx xxxx xxxx */ + DECODE_OR (0xfbff8000, 0xf20f0000), + /* SUBW Rd, PC, #imm 1111 0x10 1010 1111 0xxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0xfbff8000, 0xf2af0000, t32_emulate_rd8pc16_noflags, + REGS(PC, 0, NOSPPC, 0, 0)), + + /* ADDW SP, SP, #imm 1111 0x10 0000 1101 0xxx 1101 xxxx xxxx */ + DECODE_OR (0xfbff8f00, 0xf20d0d00), + /* SUBW SP, SP, #imm 1111 0x10 1010 1101 0xxx 1101 xxxx xxxx */ + DECODE_EMULATEX (0xfbff8f00, 0xf2ad0d00, t32_emulate_rd8rn16_noflags, + REGS(SP, 0, SP, 0, 0)), + + /* ADDW 1111 0x10 0000 xxxx 0xxx xxxx xxxx xxxx */ + DECODE_OR (0xfbf08000, 0xf2000000), + /* SUBW 1111 0x10 1010 xxxx 0xxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0xfbf08000, 0xf2a00000, t32_emulate_rd8rn16_noflags, + REGS(NOPCX, 0, NOSPPC, 0, 0)), + + /* MOVW 1111 0x10 0100 xxxx 0xxx xxxx xxxx xxxx */ + /* MOVT 1111 0x10 1100 xxxx 0xxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0xfb708000, 0xf2400000, t32_emulate_rd8rn16_noflags, + REGS(0, 0, NOSPPC, 0, 0)), + + /* SSAT16 1111 0x11 0010 xxxx 0000 xxxx 00xx xxxx */ + /* SSAT 1111 0x11 00x0 xxxx 0xxx xxxx xxxx xxxx */ + /* USAT16 1111 0x11 1010 xxxx 0000 xxxx 00xx xxxx */ + /* USAT 1111 0x11 10x0 xxxx 0xxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0xfb508000, 0xf3000000, t32_emulate_rd8rn16rm0_rwflags, + REGS(NOSPPC, 0, NOSPPC, 0, 0)), + + /* SFBX 1111 0x11 0100 xxxx 0xxx xxxx xxxx xxxx */ + /* UFBX 1111 0x11 1100 xxxx 0xxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0xfb708000, 0xf3400000, t32_emulate_rd8rn16_noflags, + REGS(NOSPPC, 0, NOSPPC, 0, 0)), + + /* BFC 1111 0x11 0110 1111 0xxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0xfbff8000, 0xf36f0000, t32_emulate_rd8rn16_noflags, + REGS(0, 0, NOSPPC, 0, 0)), + + /* BFI 1111 0x11 0110 xxxx 0xxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0xfbf08000, 0xf3600000, t32_emulate_rd8rn16_noflags, + REGS(NOSPPCX, 0, NOSPPC, 0, 0)), + + DECODE_END +}; + static const union decode_item t32_table_1111_0xxx___1[] = { /* Branches and miscellaneous control */ @@ -334,6 +423,12 @@ const union decode_item kprobe_decode_thumb32_table[] = { */ DECODE_TABLE (0xfa008000, 0xf0000000, t32_table_1111_0x0x___0), + /* + * Data-processing (plain binary immediate) + * 1111 0x1x xxxx xxxx 0xxx xxxx xxxx xxxx + */ + DECODE_TABLE (0xfa008000, 0xf2000000, t32_table_1111_0x1x___0), + /* * Branches and miscellaneous control * 1111 0xxx xxxx xxxx 1xxx xxxx xxxx xxxx -- 2.20.1