ARM: use a function table for determining instruction interpreter action

Make the instruction interpreter call back to semantic action functions
through a function pointer array provided by the invoker.  The interpreter
decodes the instructions into groups and uses the group number to index
into the supplied array.  kprobes and uprobes code will each supply their
own array of functions.
Signed-off-by: NDavid A. Long <dave.long@linaro.org>
Acked-by: NJon Medhurst <tixy@linaro.org>

arch/arm/kernel/kprobes-arm.c

@@ -73,7 +73,7 @@
 #endif
 
 
-void __kprobes
+static void __kprobes
 emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -102,7 +102,7 @@ emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs)
 		regs->uregs[rn] = rnv;
 }
 
-void __kprobes
+static void __kprobes
 emulate_ldr(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -132,7 +132,7 @@ emulate_ldr(struct kprobe *p, struct pt_regs *regs)
 		regs->uregs[rn] = rnv;
 }
 
-void __kprobes
+static void __kprobes
 emulate_str(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -159,7 +159,7 @@ emulate_str(struct kprobe *p, struct pt_regs *regs)
 		regs->uregs[rn] = rnv;
 }
 
-void __kprobes
+static void __kprobes
 emulate_rd12rn16rm0rs8_rwflags(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -194,7 +194,7 @@ emulate_rd12rn16rm0rs8_rwflags(struct kprobe *p, struct pt_regs *regs)
 	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
 }
 
-void __kprobes
+static void __kprobes
 emulate_rd12rn16rm0_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -221,7 +221,7 @@ emulate_rd12rn16rm0_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
 	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
 }
 
-void __kprobes
+static void __kprobes
 emulate_rd16rn12rm0rs8_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -250,7 +250,7 @@ emulate_rd16rn12rm0rs8_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
 	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
 }
 
-void __kprobes
+static void __kprobes
 emulate_rd12rm0_noflags_nopc(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -270,7 +270,7 @@ emulate_rd12rm0_noflags_nopc(struct kprobe *p, struct pt_regs *regs)
 	regs->uregs[rd] = rdv;
 }
 
-void __kprobes
+static void __kprobes
 emulate_rdlo12rdhi16rn0rm8_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -299,3 +299,44 @@ emulate_rdlo12rdhi16rn0rm8_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
 	regs->uregs[rdhi] = rdhiv;
 	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
 }
+
+const union decode_action kprobes_arm_actions[NUM_PROBES_ARM_ACTIONS] = {
+	[PROBES_EMULATE_NONE] = {.handler = kprobe_emulate_none},
+	[PROBES_SIMULATE_NOP] = {.handler = kprobe_simulate_nop},
+	[PROBES_PRELOAD_IMM] = {.handler = kprobe_simulate_nop},
+	[PROBES_PRELOAD_REG] = {.handler = kprobe_simulate_nop},
+	[PROBES_BRANCH_IMM] = {.handler = simulate_blx1},
+	[PROBES_MRS] = {.handler = simulate_mrs},
+	[PROBES_BRANCH_REG] = {.handler = simulate_blx2bx},
+	[PROBES_CLZ] = {.handler = emulate_rd12rm0_noflags_nopc},
+	[PROBES_SATURATING_ARITHMETIC] = {
+		.handler = emulate_rd12rn16rm0_rwflags_nopc},
+	[PROBES_MUL1] = {.handler = emulate_rdlo12rdhi16rn0rm8_rwflags_nopc},
+	[PROBES_MUL2] = {.handler = emulate_rd16rn12rm0rs8_rwflags_nopc},
+	[PROBES_SWP] = {.handler = emulate_rd12rn16rm0_rwflags_nopc},
+	[PROBES_LDRSTRD] = {.handler = emulate_ldrdstrd},
+	[PROBES_LOAD_EXTRA] = {.handler = emulate_ldr},
+	[PROBES_LOAD] = {.handler = emulate_ldr},
+	[PROBES_STORE_EXTRA] = {.handler = emulate_str},
+	[PROBES_STORE] = {.handler = emulate_str},
+	[PROBES_MOV_IP_SP] = {.handler = simulate_mov_ipsp},
+	[PROBES_DATA_PROCESSING_REG] = {
+		.handler = emulate_rd12rn16rm0rs8_rwflags},
+	[PROBES_DATA_PROCESSING_IMM] = {
+		.handler = emulate_rd12rn16rm0rs8_rwflags},
+	[PROBES_MOV_HALFWORD] = {.handler = emulate_rd12rm0_noflags_nopc},
+	[PROBES_SEV] = {.handler = kprobe_emulate_none},
+	[PROBES_WFE] = {.handler = kprobe_simulate_nop},
+	[PROBES_SATURATE] = {.handler = emulate_rd12rn16rm0_rwflags_nopc},
+	[PROBES_REV] = {.handler = emulate_rd12rm0_noflags_nopc},
+	[PROBES_MMI] = {.handler = emulate_rd12rn16rm0_rwflags_nopc},
+	[PROBES_PACK] = {.handler = emulate_rd12rn16rm0_rwflags_nopc},
+	[PROBES_EXTEND] = {.handler = emulate_rd12rm0_noflags_nopc},
+	[PROBES_EXTEND_ADD] = {.handler = emulate_rd12rn16rm0_rwflags_nopc},
+	[PROBES_MUL_ADD_LONG] = {
+		.handler = emulate_rdlo12rdhi16rn0rm8_rwflags_nopc},
+	[PROBES_MUL_ADD] = {.handler = emulate_rd16rn12rm0rs8_rwflags_nopc},
+	[PROBES_BITFIELD] = {.handler = emulate_rd12rm0_noflags_nopc},
+	[PROBES_BRANCH] = {.handler = simulate_bbl},
+	[PROBES_LDMSTM] = {.decoder = kprobe_decode_ldmstm}
+};

arch/arm/kernel/kprobes-common.c

@@ -112,7 +112,8 @@ emulate_ldm_r3_15(struct kprobe *p, struct pt_regs *regs)
 }
 
 enum kprobe_insn __kprobes
-kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi)
+kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi,
+		const struct decode_header *h)
 {
 	kprobe_insn_handler_t *handler = 0;
 	unsigned reglist = insn & 0xffff;

arch/arm/kernel/kprobes-thumb.c

@@ -16,6 +16,10 @@
 #include "kprobes.h"
 #include "probes-thumb.h"
 
+/* These emulation encodings are functionally equivalent... */
+#define t32_emulate_rd8rn16rm0ra12_noflags \
+		t32_emulate_rdlo12rdhi8rn16rm0_noflags
+
 /*
  * Return the PC value for a probe in thumb code.
  * This is the address of the probed instruction plus 4.
@@ -29,7 +33,7 @@ static inline unsigned long __kprobes thumb_probe_pc(struct kprobe *p)
 
 /* t32 thumb actions */
 
-void __kprobes
+static void __kprobes
 t32_simulate_table_branch(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -49,7 +53,7 @@ t32_simulate_table_branch(struct kprobe *p, struct pt_regs *regs)
 	regs->ARM_pc = pc + 2 * halfwords;
 }
 
-void __kprobes
+static void __kprobes
 t32_simulate_mrs(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -58,7 +62,7 @@ t32_simulate_mrs(struct kprobe *p, struct pt_regs *regs)
 	regs->uregs[rd] = regs->ARM_cpsr & mask;
 }
 
-void __kprobes
+static void __kprobes
 t32_simulate_cond_branch(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -73,8 +77,9 @@ t32_simulate_cond_branch(struct kprobe *p, struct pt_regs *regs)
 	regs->ARM_pc = pc + (offset * 2);
 }
 
-enum kprobe_insn __kprobes
-t32_decode_cond_branch(kprobe_opcode_t insn, struct arch_specific_insn *asi)
+static enum kprobe_insn __kprobes
+t32_decode_cond_branch(kprobe_opcode_t insn, struct arch_specific_insn *asi,
+		const struct decode_header *d)
 {
 	int cc = (insn >> 22) & 0xf;
 	asi->insn_check_cc = kprobe_condition_checks[cc];
@@ -82,7 +87,7 @@ t32_decode_cond_branch(kprobe_opcode_t insn, struct arch_specific_insn *asi)
 	return INSN_GOOD_NO_SLOT;
 }
 
-void __kprobes
+static void __kprobes
 t32_simulate_branch(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -110,7 +115,7 @@ t32_simulate_branch(struct kprobe *p, struct pt_regs *regs)
 	regs->ARM_pc = pc + (offset * 2);
 }
 
-void __kprobes
+static void __kprobes
 t32_simulate_ldr_literal(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -148,10 +153,11 @@ t32_simulate_ldr_literal(struct kprobe *p, struct pt_regs *regs)
 	regs->uregs[rt] = rtv;
 }
 
-enum kprobe_insn __kprobes
-t32_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi)
+static enum kprobe_insn __kprobes
+t32_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi,
+		const struct decode_header *d)
 {
-	enum kprobe_insn ret = kprobe_decode_ldmstm(insn, asi);
+	enum kprobe_insn ret = kprobe_decode_ldmstm(insn, asi, d);
 
 	/* Fixup modified instruction to have halfwords in correct order...*/
 	insn = asi->insn[0];
@@ -161,7 +167,7 @@ t32_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi)
 	return ret;
 }
 
-void __kprobes
+static void __kprobes
 t32_emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -188,7 +194,7 @@ t32_emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs)
 	regs->uregs[rt2] = rt2v;
 }
 
-void __kprobes
+static void __kprobes
 t32_emulate_ldrstr(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -214,7 +220,7 @@ t32_emulate_ldrstr(struct kprobe *p, struct pt_regs *regs)
 		regs->uregs[rt] = rtv;
 }
 
-void __kprobes
+static void __kprobes
 t32_emulate_rd8rn16rm0_rwflags(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -241,7 +247,7 @@ t32_emulate_rd8rn16rm0_rwflags(struct kprobe *p, struct pt_regs *regs)
 	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
 }
 
-void __kprobes
+static void __kprobes
 t32_emulate_rd8pc16_noflags(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -261,7 +267,7 @@ t32_emulate_rd8pc16_noflags(struct kprobe *p, struct pt_regs *regs)
 	regs->uregs[rd] = rdv;
 }
 
-void __kprobes
+static void __kprobes
 t32_emulate_rd8rn16_noflags(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -281,7 +287,7 @@ t32_emulate_rd8rn16_noflags(struct kprobe *p, struct pt_regs *regs)
 	regs->uregs[rd] = rdv;
 }
 
-void __kprobes
+static void __kprobes
 t32_emulate_rdlo12rdhi8rn16rm0_noflags(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -308,7 +314,7 @@ t32_emulate_rdlo12rdhi8rn16rm0_noflags(struct kprobe *p, struct pt_regs *regs)
 }
 /* t16 thumb actions */
 
-void __kprobes
+static void __kprobes
 t16_simulate_bxblx(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -322,7 +328,7 @@ t16_simulate_bxblx(struct kprobe *p, struct pt_regs *regs)
 	bx_write_pc(rmv, regs);
 }
 
-void __kprobes
+static void __kprobes
 t16_simulate_ldr_literal(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -332,7 +338,7 @@ t16_simulate_ldr_literal(struct kprobe *p, struct pt_regs *regs)
 	regs->uregs[rt] = base[index];
 }
 
-void __kprobes
+static void __kprobes
 t16_simulate_ldrstr_sp_relative(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -345,7 +351,7 @@ t16_simulate_ldrstr_sp_relative(struct kprobe *p, struct pt_regs *regs)
 		base[index] = regs->uregs[rt];
 }
 
-void __kprobes
+static void __kprobes
 t16_simulate_reladr(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -356,7 +362,7 @@ t16_simulate_reladr(struct kprobe *p, struct pt_regs *regs)
 	regs->uregs[rt] = base + offset * 4;
 }
 
-void __kprobes
+static void __kprobes
 t16_simulate_add_sp_imm(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -367,7 +373,7 @@ t16_simulate_add_sp_imm(struct kprobe *p, struct pt_regs *regs)
 		regs->ARM_sp += imm * 4;
 }
 
-void __kprobes
+static void __kprobes
 t16_simulate_cbz(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -381,7 +387,7 @@ t16_simulate_cbz(struct kprobe *p, struct pt_regs *regs)
 	}
 }
 
-void __kprobes
+static void __kprobes
 t16_simulate_it(struct kprobe *p, struct pt_regs *regs)
 {
 	/*
@@ -398,21 +404,22 @@ t16_simulate_it(struct kprobe *p, struct pt_regs *regs)
 	regs->ARM_cpsr = cpsr;
 }
 
-void __kprobes
+static void __kprobes
 t16_singlestep_it(struct kprobe *p, struct pt_regs *regs)
 {
 	regs->ARM_pc += 2;
 	t16_simulate_it(p, regs);
 }
 
-enum kprobe_insn __kprobes
-t16_decode_it(kprobe_opcode_t insn, struct arch_specific_insn *asi)
+static enum kprobe_insn __kprobes
+t16_decode_it(kprobe_opcode_t insn, struct arch_specific_insn *asi,
+		const struct decode_header *d)
 {
 	asi->insn_singlestep = t16_singlestep_it;
 	return INSN_GOOD_NO_SLOT;
 }
 
-void __kprobes
+static void __kprobes
 t16_simulate_cond_branch(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -422,8 +429,9 @@ t16_simulate_cond_branch(struct kprobe *p, struct pt_regs *regs)
 	regs->ARM_pc = pc + (offset * 2);
 }
 
-enum kprobe_insn __kprobes
-t16_decode_cond_branch(kprobe_opcode_t insn, struct arch_specific_insn *asi)
+static enum kprobe_insn __kprobes
+t16_decode_cond_branch(kprobe_opcode_t insn, struct arch_specific_insn *asi,
+		const struct decode_header *d)
 {
 	int cc = (insn >> 8) & 0xf;
 	asi->insn_check_cc = kprobe_condition_checks[cc];
@@ -431,7 +439,7 @@ t16_decode_cond_branch(kprobe_opcode_t insn, struct arch_specific_insn *asi)
 	return INSN_GOOD_NO_SLOT;
 }
 
-void __kprobes
+static void __kprobes
 t16_simulate_branch(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -463,13 +471,13 @@ t16_emulate_loregs(struct kprobe *p, struct pt_regs *regs)
 	return (oldcpsr & ~APSR_MASK) | (newcpsr & APSR_MASK);
 }
 
-void __kprobes
+static void __kprobes
 t16_emulate_loregs_rwflags(struct kprobe *p, struct pt_regs *regs)
 {
 	regs->ARM_cpsr = t16_emulate_loregs(p, regs);
 }
 
-void __kprobes
+static void __kprobes
 t16_emulate_loregs_noitrwflags(struct kprobe *p, struct pt_regs *regs)
 {
 	unsigned long cpsr = t16_emulate_loregs(p, regs);
@@ -477,7 +485,7 @@ t16_emulate_loregs_noitrwflags(struct kprobe *p, struct pt_regs *regs)
 		regs->ARM_cpsr = cpsr;
 }
 
-void __kprobes
+static void __kprobes
 t16_emulate_hiregs(struct kprobe *p, struct pt_regs *regs)
 {
 	kprobe_opcode_t insn = p->opcode;
@@ -508,8 +516,9 @@ t16_emulate_hiregs(struct kprobe *p, struct pt_regs *regs)
 	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
 }
 
-enum kprobe_insn __kprobes
-t16_decode_hiregs(kprobe_opcode_t insn, struct arch_specific_insn *asi)
+static enum kprobe_insn __kprobes
+t16_decode_hiregs(kprobe_opcode_t insn, struct arch_specific_insn *asi,
+		const struct decode_header *d)
 {
 	insn &= ~0x00ff;
 	insn |= 0x001; /* Set Rdn = R1 and Rm = R0 */
@@ -518,7 +527,7 @@ t16_decode_hiregs(kprobe_opcode_t insn, struct arch_specific_insn *asi)
 	return INSN_GOOD;
 }
 
-void __kprobes
+static void __kprobes
 t16_emulate_push(struct kprobe *p, struct pt_regs *regs)
 {
 	__asm__ __volatile__ (
@@ -534,8 +543,9 @@ t16_emulate_push(struct kprobe *p, struct pt_regs *regs)
 		);
 }
 
-enum kprobe_insn __kprobes
-t16_decode_push(kprobe_opcode_t insn, struct arch_specific_insn *asi)
+static enum kprobe_insn __kprobes
+t16_decode_push(kprobe_opcode_t insn, struct arch_specific_insn *asi,
+		const struct decode_header *d)
 {
 	/*
 	 * To simulate a PUSH we use a Thumb-2 "STMDB R9!, {registers}"
@@ -548,7 +558,7 @@ t16_decode_push(kprobe_opcode_t insn, struct arch_specific_insn *asi)
 	return INSN_GOOD;
 }
 
-void __kprobes
+static void __kprobes
 t16_emulate_pop_nopc(struct kprobe *p, struct pt_regs *regs)
 {
 	__asm__ __volatile__ (
@@ -564,7 +574,7 @@ t16_emulate_pop_nopc(struct kprobe *p, struct pt_regs *regs)
 		);
 }
 
-void __kprobes
+static void __kprobes
 t16_emulate_pop_pc(struct kprobe *p, struct pt_regs *regs)
 {
 	register unsigned long pc asm("r8");
@@ -584,8 +594,9 @@ t16_emulate_pop_pc(struct kprobe *p, struct pt_regs *regs)
 	bx_write_pc(pc, regs);
 }
 
-enum kprobe_insn __kprobes
-t16_decode_pop(kprobe_opcode_t insn, struct arch_specific_insn *asi)
+static enum kprobe_insn __kprobes
+t16_decode_pop(kprobe_opcode_t insn, struct arch_specific_insn *asi,
+		const struct decode_header *d)
 {
 	/*
 	 * To simulate a POP we use a Thumb-2 "LDMDB R9!, {registers}"
@@ -598,3 +609,57 @@ t16_decode_pop(kprobe_opcode_t insn, struct arch_specific_insn *asi)
 					 : t16_emulate_pop_nopc;
 	return INSN_GOOD;
 }
+
+const union decode_action kprobes_t16_actions[NUM_PROBES_T16_ACTIONS] = {
+	[PROBES_T16_ADD_SP] = {.handler = t16_simulate_add_sp_imm},
+	[PROBES_T16_CBZ] = {.handler = t16_simulate_cbz},
+	[PROBES_T16_SIGN_EXTEND] = {.handler = t16_emulate_loregs_rwflags},
+	[PROBES_T16_PUSH] = {.decoder = t16_decode_push},
+	[PROBES_T16_POP] = {.decoder = t16_decode_pop},
+	[PROBES_T16_SEV] = {.handler = kprobe_emulate_none},
+	[PROBES_T16_WFE] = {.handler = kprobe_simulate_nop},
+	[PROBES_T16_IT] = {.decoder = t16_decode_it},
+	[PROBES_T16_CMP] = {.handler = t16_emulate_loregs_rwflags},
+	[PROBES_T16_ADDSUB] = {.handler = t16_emulate_loregs_noitrwflags},
+	[PROBES_T16_LOGICAL] = {.handler = t16_emulate_loregs_noitrwflags},
+	[PROBES_T16_LDR_LIT] = {.handler = t16_simulate_ldr_literal},
+	[PROBES_T16_BLX] = {.handler = t16_simulate_bxblx},
+	[PROBES_T16_HIREGOPS] = {.decoder = t16_decode_hiregs},
+	[PROBES_T16_LDRHSTRH] = {.handler = t16_emulate_loregs_rwflags},
+	[PROBES_T16_LDRSTR] = {.handler = t16_simulate_ldrstr_sp_relative},
+	[PROBES_T16_ADR] = {.handler = t16_simulate_reladr},
+	[PROBES_T16_LDMSTM] = {.handler = t16_emulate_loregs_rwflags},
+	[PROBES_T16_BRANCH_COND] = {.decoder = t16_decode_cond_branch},
+	[PROBES_T16_BRANCH] = {.handler = t16_simulate_branch},
+};
+
+const union decode_action kprobes_t32_actions[NUM_PROBES_T32_ACTIONS] = {
+	[PROBES_T32_LDMSTM] = {.decoder = t32_decode_ldmstm},
+	[PROBES_T32_LDRDSTRD] = {.handler = t32_emulate_ldrdstrd},
+	[PROBES_T32_TABLE_BRANCH] = {.handler = t32_simulate_table_branch},
+	[PROBES_T32_TST] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
+	[PROBES_T32_MOV] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
+	[PROBES_T32_ADDSUB] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
+	[PROBES_T32_LOGICAL] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
+	[PROBES_T32_CMP] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
+	[PROBES_T32_ADDWSUBW_PC] = {.handler = t32_emulate_rd8pc16_noflags,},
+	[PROBES_T32_ADDWSUBW] = {.handler = t32_emulate_rd8rn16_noflags},
+	[PROBES_T32_MOVW] = {.handler = t32_emulate_rd8rn16_noflags},
+	[PROBES_T32_SAT] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
+	[PROBES_T32_BITFIELD] = {.handler = t32_emulate_rd8rn16_noflags},
+	[PROBES_T32_SEV] = {.handler = kprobe_emulate_none},
+	[PROBES_T32_WFE] = {.handler = kprobe_simulate_nop},
+	[PROBES_T32_MRS] = {.handler = t32_simulate_mrs},
+	[PROBES_T32_BRANCH_COND] = {.decoder = t32_decode_cond_branch},
+	[PROBES_T32_BRANCH] = {.handler = t32_simulate_branch},
+	[PROBES_T32_PLDI] = {.handler = kprobe_simulate_nop},
+	[PROBES_T32_LDR_LIT] = {.handler = t32_simulate_ldr_literal},
+	[PROBES_T32_LDRSTR] = {.handler = t32_emulate_ldrstr},
+	[PROBES_T32_SIGN_EXTEND] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
+	[PROBES_T32_MEDIA] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
+	[PROBES_T32_REVERSE] = {.handler = t32_emulate_rd8rn16_noflags},
+	[PROBES_T32_MUL_ADD] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
+	[PROBES_T32_MUL_ADD2] = {.handler = t32_emulate_rd8rn16rm0ra12_noflags},
+	[PROBES_T32_MUL_ADD_LONG] = {
+		.handler = t32_emulate_rdlo12rdhi8rn16rm0_noflags},
+};

arch/arm/kernel/kprobes.c

@@ -56,6 +56,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
 	unsigned long addr = (unsigned long)p->addr;
 	bool thumb;
 	kprobe_decode_insn_t *decode_insn;
+	const union decode_action *actions;
 	int is;
 
 	if (in_exception_text(addr))
@@ -69,20 +70,24 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
 		insn <<= 16;
 		insn |= ((u16 *)addr)[1];
 		decode_insn = thumb32_kprobe_decode_insn;
-	} else
+		actions = kprobes_t32_actions;
+	} else {
 		decode_insn = thumb16_kprobe_decode_insn;
+		actions = kprobes_t16_actions;
+	}
 #else /* !CONFIG_THUMB2_KERNEL */
 	thumb = false;
 	if (addr & 0x3)
 		return -EINVAL;
 	insn = *p->addr;
 	decode_insn = arm_kprobe_decode_insn;
+	actions = kprobes_arm_actions;
 #endif
 
 	p->opcode = insn;
 	p->ainsn.insn = tmp_insn;
 
-	switch ((*decode_insn)(insn, &p->ainsn)) {
+	switch ((*decode_insn)(insn, &p->ainsn, actions)) {
 	case INSN_REJECTED:	/* not supported */
 		return -EINVAL;
 

arch/arm/kernel/kprobes.h

@@ -27,6 +27,8 @@
 #define KPROBE_THUMB16_BREAKPOINT_INSTRUCTION	0xde18
 #define KPROBE_THUMB32_BREAKPOINT_INSTRUCTION	0xf7f0a018
 
+struct decode_header;
+union decode_action;
 
 enum kprobe_insn {
 	INSN_REJECTED,
@@ -35,19 +37,24 @@ enum kprobe_insn {
 };
 
 typedef enum kprobe_insn (kprobe_decode_insn_t)(kprobe_opcode_t,
-						struct arch_specific_insn *);
+						struct arch_specific_insn *,
+						const union decode_action *);
 
 #ifdef CONFIG_THUMB2_KERNEL
 
 enum kprobe_insn thumb16_kprobe_decode_insn(kprobe_opcode_t,
-						struct arch_specific_insn *);
+					    struct arch_specific_insn *,
+					    const union decode_action *);
 enum kprobe_insn thumb32_kprobe_decode_insn(kprobe_opcode_t,
-						struct arch_specific_insn *);
+					    struct arch_specific_insn *,
+					    const union decode_action *);
 
 #else /* !CONFIG_THUMB2_KERNEL */
 
 enum kprobe_insn arm_kprobe_decode_insn(kprobe_opcode_t,
-					struct arch_specific_insn *);
+					struct arch_specific_insn *,
+					const union decode_action *);
+
 #endif
 
 void __init arm_kprobe_decode_init(void);

arch/arm/kernel/probes-arm.c

@@ -126,16 +126,16 @@ static const union decode_item arm_1111_table[] = {
 	/* PLDI (immediate)	1111 0100 x101 xxxx xxxx xxxx xxxx xxxx */
 	/* PLDW (immediate)	1111 0101 x001 xxxx xxxx xxxx xxxx xxxx */
 	/* PLD (immediate)	1111 0101 x101 xxxx xxxx xxxx xxxx xxxx */
-	DECODE_SIMULATE	(0xfe300000, 0xf4100000, kprobe_simulate_nop),
+	DECODE_SIMULATE	(0xfe300000, 0xf4100000, PROBES_PRELOAD_IMM),
 
 	/* memory hint		1111 0110 x001 xxxx xxxx xxxx xxx0 xxxx */
 	/* PLDI (register)	1111 0110 x101 xxxx xxxx xxxx xxx0 xxxx */
 	/* PLDW (register)	1111 0111 x001 xxxx xxxx xxxx xxx0 xxxx */
 	/* PLD (register)	1111 0111 x101 xxxx xxxx xxxx xxx0 xxxx */
-	DECODE_SIMULATE	(0xfe300010, 0xf6100000, kprobe_simulate_nop),
+	DECODE_SIMULATE	(0xfe300010, 0xf6100000, PROBES_PRELOAD_REG),
 
 	/* BLX (immediate)	1111 101x xxxx xxxx xxxx xxxx xxxx xxxx */
-	DECODE_SIMULATE	(0xfe000000, 0xfa000000, simulate_blx1),
+	DECODE_SIMULATE	(0xfe000000, 0xfa000000, PROBES_BRANCH_IMM),
 
 	/* CPS			1111 0001 0000 xxx0 xxxx xxxx xx0x xxxx */
 	/* SETEND		1111 0001 0000 0001 xxxx xxxx 0000 xxxx */
@@ -159,25 +159,25 @@ static const union decode_item arm_cccc_0001_0xx0____0xxx_table[] = {
 	/* Miscellaneous instructions					*/
 
 	/* MRS cpsr		cccc 0001 0000 xxxx xxxx xxxx 0000 xxxx */
-	DECODE_SIMULATEX(0x0ff000f0, 0x01000000, simulate_mrs,
+	DECODE_SIMULATEX(0x0ff000f0, 0x01000000, PROBES_MRS,
 						 REGS(0, NOPC, 0, 0, 0)),
 
 	/* BX			cccc 0001 0010 xxxx xxxx xxxx 0001 xxxx */
-	DECODE_SIMULATE	(0x0ff000f0, 0x01200010, simulate_blx2bx),
+	DECODE_SIMULATE	(0x0ff000f0, 0x01200010, PROBES_BRANCH_REG),
 
 	/* BLX (register)	cccc 0001 0010 xxxx xxxx xxxx 0011 xxxx */
-	DECODE_SIMULATEX(0x0ff000f0, 0x01200030, simulate_blx2bx,
+	DECODE_SIMULATEX(0x0ff000f0, 0x01200030, PROBES_BRANCH_REG,
 						 REGS(0, 0, 0, 0, NOPC)),
 
 	/* CLZ			cccc 0001 0110 xxxx xxxx xxxx 0001 xxxx */
-	DECODE_EMULATEX	(0x0ff000f0, 0x01600010, emulate_rd12rm0_noflags_nopc,
+	DECODE_EMULATEX	(0x0ff000f0, 0x01600010, PROBES_CLZ,
 						 REGS(0, NOPC, 0, 0, NOPC)),
 
 	/* QADD			cccc 0001 0000 xxxx xxxx xxxx 0101 xxxx */
 	/* QSUB			cccc 0001 0010 xxxx xxxx xxxx 0101 xxxx */
 	/* QDADD		cccc 0001 0100 xxxx xxxx xxxx 0101 xxxx */
 	/* QDSUB		cccc 0001 0110 xxxx xxxx xxxx 0101 xxxx */
-	DECODE_EMULATEX	(0x0f9000f0, 0x01000050, emulate_rd12rn16rm0_rwflags_nopc,
+	DECODE_EMULATEX	(0x0f9000f0, 0x01000050, PROBES_SATURATING_ARITHMETIC,
 						 REGS(NOPC, NOPC, 0, 0, NOPC)),
 
 	/* BXJ			cccc 0001 0010 xxxx xxxx xxxx 0010 xxxx */
@@ -193,19 +193,19 @@ static const union decode_item arm_cccc_0001_0xx0____1xx0_table[] = {
 	/* Halfword multiply and multiply-accumulate			*/
 
 	/* SMLALxy		cccc 0001 0100 xxxx xxxx xxxx 1xx0 xxxx */
-	DECODE_EMULATEX	(0x0ff00090, 0x01400080, emulate_rdlo12rdhi16rn0rm8_rwflags_nopc,
+	DECODE_EMULATEX	(0x0ff00090, 0x01400080, PROBES_MUL1,
 						 REGS(NOPC, NOPC, NOPC, 0, NOPC)),
 
 	/* SMULWy		cccc 0001 0010 xxxx xxxx xxxx 1x10 xxxx */
 	DECODE_OR	(0x0ff000b0, 0x012000a0),
 	/* SMULxy		cccc 0001 0110 xxxx xxxx xxxx 1xx0 xxxx */
-	DECODE_EMULATEX	(0x0ff00090, 0x01600080, emulate_rd16rn12rm0rs8_rwflags_nopc,
+	DECODE_EMULATEX	(0x0ff00090, 0x01600080, PROBES_MUL2,
 						 REGS(NOPC, 0, NOPC, 0, NOPC)),
 
 	/* SMLAxy		cccc 0001 0000 xxxx xxxx xxxx 1xx0 xxxx */
 	DECODE_OR	(0x0ff00090, 0x01000080),
 	/* SMLAWy		cccc 0001 0010 xxxx xxxx xxxx 1x00 xxxx */
-	DECODE_EMULATEX	(0x0ff000b0, 0x01200080, emulate_rd16rn12rm0rs8_rwflags_nopc,
+	DECODE_EMULATEX	(0x0ff000b0, 0x01200080, PROBES_MUL2,
 						 REGS(NOPC, NOPC, NOPC, 0, NOPC)),
 
 	DECODE_END
@@ -216,14 +216,14 @@ static const union decode_item arm_cccc_0000_____1001_table[] = {
 
 	/* MUL			cccc 0000 0000 xxxx xxxx xxxx 1001 xxxx */
 	/* MULS			cccc 0000 0001 xxxx xxxx xxxx 1001 xxxx */
-	DECODE_EMULATEX	(0x0fe000f0, 0x00000090, emulate_rd16rn12rm0rs8_rwflags_nopc,
+	DECODE_EMULATEX	(0x0fe000f0, 0x00000090, PROBES_MUL2,
 						 REGS(NOPC, 0, NOPC, 0, NOPC)),
 
 	/* MLA			cccc 0000 0010 xxxx xxxx xxxx 1001 xxxx */
 	/* MLAS			cccc 0000 0011 xxxx xxxx xxxx 1001 xxxx */
 	DECODE_OR	(0x0fe000f0, 0x00200090),
 	/* MLS			cccc 0000 0110 xxxx xxxx xxxx 1001 xxxx */
-	DECODE_EMULATEX	(0x0ff000f0, 0x00600090, emulate_rd16rn12rm0rs8_rwflags_nopc,
+	DECODE_EMULATEX	(0x0ff000f0, 0x00600090, PROBES_MUL2,
 						 REGS(NOPC, NOPC, NOPC, 0, NOPC)),
 
 	/* UMAAL		cccc 0000 0100 xxxx xxxx xxxx 1001 xxxx */
@@ -236,7 +236,7 @@ static const union decode_item arm_cccc_0000_____1001_table[] = {
 	/* SMULLS		cccc 0000 1101 xxxx xxxx xxxx 1001 xxxx */
 	/* SMLAL		cccc 0000 1110 xxxx xxxx xxxx 1001 xxxx */
 	/* SMLALS		cccc 0000 1111 xxxx xxxx xxxx 1001 xxxx */
-	DECODE_EMULATEX	(0x0f8000f0, 0x00800090, emulate_rdlo12rdhi16rn0rm8_rwflags_nopc,
+	DECODE_EMULATEX	(0x0f8000f0, 0x00800090, PROBES_MUL1,
 						 REGS(NOPC, NOPC, NOPC, 0, NOPC)),
 
 	DECODE_END
@@ -248,7 +248,7 @@ static const union decode_item arm_cccc_0001_____1001_table[] = {
 #if __LINUX_ARM_ARCH__ < 6
 	/* Deprecated on ARMv6 and may be UNDEFINED on v7		*/
 	/* SMP/SWPB		cccc 0001 0x00 xxxx xxxx xxxx 1001 xxxx */
-	DECODE_EMULATEX	(0x0fb000f0, 0x01000090, emulate_rd12rn16rm0_rwflags_nopc,
+	DECODE_EMULATEX	(0x0fb000f0, 0x01000090, PROBES_SWP,
 						 REGS(NOPC, NOPC, 0, 0, NOPC)),
 #endif
 	/* LDREX/STREX{,D,B,H}	cccc 0001 1xxx xxxx xxxx xxxx 1001 xxxx */
@@ -271,32 +271,32 @@ static const union decode_item arm_cccc_000x_____1xx1_table[] = {
 
 	/* LDRD (register)	cccc 000x x0x0 xxxx xxxx xxxx 1101 xxxx */
 	/* STRD (register)	cccc 000x x0x0 xxxx xxxx xxxx 1111 xxxx */
-	DECODE_EMULATEX	(0x0e5000d0, 0x000000d0, emulate_ldrdstrd,
+	DECODE_EMULATEX	(0x0e5000d0, 0x000000d0, PROBES_LDRSTRD,
 						 REGS(NOPCWB, NOPCX, 0, 0, NOPC)),
 
 	/* LDRD (immediate)	cccc 000x x1x0 xxxx xxxx xxxx 1101 xxxx */
 	/* STRD (immediate)	cccc 000x x1x0 xxxx xxxx xxxx 1111 xxxx */
-	DECODE_EMULATEX	(0x0e5000d0, 0x004000d0, emulate_ldrdstrd,
+	DECODE_EMULATEX	(0x0e5000d0, 0x004000d0, PROBES_LDRSTRD,
 						 REGS(NOPCWB, NOPCX, 0, 0, 0)),
 
 	/* STRH (register)	cccc 000x x0x0 xxxx xxxx xxxx 1011 xxxx */
-	DECODE_EMULATEX	(0x0e5000f0, 0x000000b0, emulate_str,
+	DECODE_EMULATEX	(0x0e5000f0, 0x000000b0, PROBES_STORE_EXTRA,
 						 REGS(NOPCWB, NOPC, 0, 0, NOPC)),
 
 	/* LDRH (register)	cccc 000x x0x1 xxxx xxxx xxxx 1011 xxxx */
 	/* LDRSB (register)	cccc 000x x0x1 xxxx xxxx xxxx 1101 xxxx */
 	/* LDRSH (register)	cccc 000x x0x1 xxxx xxxx xxxx 1111 xxxx */
-	DECODE_EMULATEX	(0x0e500090, 0x00100090, emulate_ldr,
+	DECODE_EMULATEX	(0x0e500090, 0x00100090, PROBES_LOAD_EXTRA,
 						 REGS(NOPCWB, NOPC, 0, 0, NOPC)),
 
 	/* STRH (immediate)	cccc 000x x1x0 xxxx xxxx xxxx 1011 xxxx */
-	DECODE_EMULATEX	(0x0e5000f0, 0x004000b0, emulate_str,
+	DECODE_EMULATEX	(0x0e5000f0, 0x004000b0, PROBES_STORE_EXTRA,
 						 REGS(NOPCWB, NOPC, 0, 0, 0)),
 
 	/* LDRH (immediate)	cccc 000x x1x1 xxxx xxxx xxxx 1011 xxxx */
 	/* LDRSB (immediate)	cccc 000x x1x1 xxxx xxxx xxxx 1101 xxxx */
 	/* LDRSH (immediate)	cccc 000x x1x1 xxxx xxxx xxxx 1111 xxxx */
-	DECODE_EMULATEX	(0x0e500090, 0x00500090, emulate_ldr,
+	DECODE_EMULATEX	(0x0e500090, 0x00500090, PROBES_LOAD_EXTRA,
 						 REGS(NOPCWB, NOPC, 0, 0, 0)),
 
 	DECODE_END
@@ -309,18 +309,18 @@ static const union decode_item arm_cccc_000x_table[] = {
 	DECODE_REJECT	(0x0e10f000, 0x0010f000),
 
 	/* MOV IP, SP		1110 0001 1010 0000 1100 0000 0000 1101 */
-	DECODE_SIMULATE	(0xffffffff, 0xe1a0c00d, simulate_mov_ipsp),
+	DECODE_SIMULATE	(0xffffffff, 0xe1a0c00d, PROBES_MOV_IP_SP),
 
 	/* TST (register)	cccc 0001 0001 xxxx xxxx xxxx xxx0 xxxx */
 	/* TEQ (register)	cccc 0001 0011 xxxx xxxx xxxx xxx0 xxxx */
 	/* CMP (register)	cccc 0001 0101 xxxx xxxx xxxx xxx0 xxxx */
 	/* CMN (register)	cccc 0001 0111 xxxx xxxx xxxx xxx0 xxxx */
-	DECODE_EMULATEX	(0x0f900010, 0x01100000, emulate_rd12rn16rm0rs8_rwflags,
+	DECODE_EMULATEX	(0x0f900010, 0x01100000, PROBES_DATA_PROCESSING_REG,
 						 REGS(ANY, 0, 0, 0, ANY)),
 
 	/* MOV (register)	cccc 0001 101x xxxx xxxx xxxx xxx0 xxxx */
 	/* MVN (register)	cccc 0001 111x xxxx xxxx xxxx xxx0 xxxx */
-	DECODE_EMULATEX	(0x0fa00010, 0x01a00000, emulate_rd12rn16rm0rs8_rwflags,
+	DECODE_EMULATEX	(0x0fa00010, 0x01a00000, PROBES_DATA_PROCESSING_REG,
 						 REGS(0, ANY, 0, 0, ANY)),
 
 	/* AND (register)	cccc 0000 000x xxxx xxxx xxxx xxx0 xxxx */
@@ -333,19 +333,19 @@ static const union decode_item arm_cccc_000x_table[] = {
 	/* RSC (register)	cccc 0000 111x xxxx xxxx xxxx xxx0 xxxx */
 	/* ORR (register)	cccc 0001 100x xxxx xxxx xxxx xxx0 xxxx */
 	/* BIC (register)	cccc 0001 110x xxxx xxxx xxxx xxx0 xxxx */
-	DECODE_EMULATEX	(0x0e000010, 0x00000000, emulate_rd12rn16rm0rs8_rwflags,
+	DECODE_EMULATEX	(0x0e000010, 0x00000000, PROBES_DATA_PROCESSING_REG,
 						 REGS(ANY, ANY, 0, 0, ANY)),
 
 	/* TST (reg-shift reg)	cccc 0001 0001 xxxx xxxx xxxx 0xx1 xxxx */
 	/* TEQ (reg-shift reg)	cccc 0001 0011 xxxx xxxx xxxx 0xx1 xxxx */
 	/* CMP (reg-shift reg)	cccc 0001 0101 xxxx xxxx xxxx 0xx1 xxxx */
 	/* CMN (reg-shift reg)	cccc 0001 0111 xxxx xxxx xxxx 0xx1 xxxx */
-	DECODE_EMULATEX	(0x0f900090, 0x01100010, emulate_rd12rn16rm0rs8_rwflags,
+	DECODE_EMULATEX	(0x0f900090, 0x01100010, PROBES_DATA_PROCESSING_REG,
 						 REGS(ANY, 0, NOPC, 0, ANY)),
 
 	/* MOV (reg-shift reg)	cccc 0001 101x xxxx xxxx xxxx 0xx1 xxxx */
 	/* MVN (reg-shift reg)	cccc 0001 111x xxxx xxxx xxxx 0xx1 xxxx */
-	DECODE_EMULATEX	(0x0fa00090, 0x01a00010, emulate_rd12rn16rm0rs8_rwflags,
+	DECODE_EMULATEX	(0x0fa00090, 0x01a00010, PROBES_DATA_PROCESSING_REG,
 						 REGS(0, ANY, NOPC, 0, ANY)),
 
 	/* AND (reg-shift reg)	cccc 0000 000x xxxx xxxx xxxx 0xx1 xxxx */
@@ -358,7 +358,7 @@ static const union decode_item arm_cccc_000x_table[] = {
 	/* RSC (reg-shift reg)	cccc 0000 111x xxxx xxxx xxxx 0xx1 xxxx */
 	/* ORR (reg-shift reg)	cccc 0001 100x xxxx xxxx xxxx 0xx1 xxxx */
 	/* BIC (reg-shift reg)	cccc 0001 110x xxxx xxxx xxxx 0xx1 xxxx */
-	DECODE_EMULATEX	(0x0e000090, 0x00000010, emulate_rd12rn16rm0rs8_rwflags,
+	DECODE_EMULATEX	(0x0e000090, 0x00000010, PROBES_DATA_PROCESSING_REG,
 						 REGS(ANY, ANY, NOPC, 0, ANY)),
 
 	DECODE_END
@@ -369,17 +369,17 @@ static const union decode_item arm_cccc_001x_table[] = {
 
 	/* MOVW			cccc 0011 0000 xxxx xxxx xxxx xxxx xxxx */
 	/* MOVT			cccc 0011 0100 xxxx xxxx xxxx xxxx xxxx */
-	DECODE_EMULATEX	(0x0fb00000, 0x03000000, emulate_rd12rm0_noflags_nopc,
+	DECODE_EMULATEX	(0x0fb00000, 0x03000000, PROBES_DATA_PROCESSING_IMM,
 						 REGS(0, NOPC, 0, 0, 0)),
 
 	/* YIELD		cccc 0011 0010 0000 xxxx xxxx 0000 0001 */
 	DECODE_OR	(0x0fff00ff, 0x03200001),
 	/* SEV			cccc 0011 0010 0000 xxxx xxxx 0000 0100 */
-	DECODE_EMULATE	(0x0fff00ff, 0x03200004, kprobe_emulate_none),
+	DECODE_EMULATE	(0x0fff00ff, 0x03200004, PROBES_EMULATE_NONE),
 	/* NOP			cccc 0011 0010 0000 xxxx xxxx 0000 0000 */
 	/* WFE			cccc 0011 0010 0000 xxxx xxxx 0000 0010 */
 	/* WFI			cccc 0011 0010 0000 xxxx xxxx 0000 0011 */
-	DECODE_SIMULATE	(0x0fff00fc, 0x03200000, kprobe_simulate_nop),
+	DECODE_SIMULATE	(0x0fff00fc, 0x03200000, PROBES_SIMULATE_NOP),
 	/* DBG			cccc 0011 0010 0000 xxxx xxxx ffff xxxx */
 	/* unallocated hints	cccc 0011 0010 0000 xxxx xxxx xxxx xxxx */
 	/* MSR (immediate)	cccc 0011 0x10 xxxx xxxx xxxx xxxx xxxx */
@@ -392,12 +392,12 @@ static const union decode_item arm_cccc_001x_table[] = {
 	/* TEQ (immediate)	cccc 0011 0011 xxxx xxxx xxxx xxxx xxxx */
 	/* CMP (immediate)	cccc 0011 0101 xxxx xxxx xxxx xxxx xxxx */
 	/* CMN (immediate)	cccc 0011 0111 xxxx xxxx xxxx xxxx xxxx */
-	DECODE_EMULATEX	(0x0f900000, 0x03100000, emulate_rd12rn16rm0rs8_rwflags,
+	DECODE_EMULATEX	(0x0f900000, 0x03100000, PROBES_DATA_PROCESSING_IMM,
 						 REGS(ANY, 0, 0, 0, 0)),
 
 	/* MOV (immediate)	cccc 0011 101x xxxx xxxx xxxx xxxx xxxx */
 	/* MVN (immediate)	cccc 0011 111x xxxx xxxx xxxx xxxx xxxx */
-	DECODE_EMULATEX	(0x0fa00000, 0x03a00000, emulate_rd12rn16rm0rs8_rwflags,
+	DECODE_EMULATEX	(0x0fa00000, 0x03a00000, PROBES_DATA_PROCESSING_IMM,
 						 REGS(0, ANY, 0, 0, 0)),
 
 	/* AND (immediate)	cccc 0010 000x xxxx xxxx xxxx xxxx xxxx */
@@ -410,7 +410,7 @@ static const union decode_item arm_cccc_001x_table[] = {
 	/* RSC (immediate)	cccc 0010 111x xxxx xxxx xxxx xxxx xxxx */
 	/* ORR (immediate)	cccc 0011 100x xxxx xxxx xxxx xxxx xxxx */
 	/* BIC (immediate)	cccc 0011 110x xxxx xxxx xxxx xxxx xxxx */
-	DECODE_EMULATEX	(0x0e000000, 0x02000000, emulate_rd12rn16rm0rs8_rwflags,
+	DECODE_EMULATEX	(0x0e000000, 0x02000000, PROBES_DATA_PROCESSING_IMM,
 						 REGS(ANY, ANY, 0, 0, 0)),
 
 	DECODE_END
@@ -420,7 +420,7 @@ static const union decode_item arm_cccc_0110_____xxx1_table[] = {
 	/* Media instructions						*/
 
 	/* SEL			cccc 0110 1000 xxxx xxxx xxxx 1011 xxxx */
-	DECODE_EMULATEX	(0x0ff000f0, 0x068000b0, emulate_rd12rn16rm0_rwflags_nopc,
+	DECODE_EMULATEX	(0x0ff000f0, 0x068000b0, PROBES_SATURATE,
 						 REGS(NOPC, NOPC, 0, 0, NOPC)),
 
 	/* SSAT			cccc 0110 101x xxxx xxxx xxxx xx01 xxxx */
@@ -428,14 +428,14 @@ static const union decode_item arm_cccc_0110_____xxx1_table[] = {
 	DECODE_OR(0x0fa00030, 0x06a00010),
 	/* SSAT16		cccc 0110 1010 xxxx xxxx xxxx 0011 xxxx */
 	/* USAT16		cccc 0110 1110 xxxx xxxx xxxx 0011 xxxx */
-	DECODE_EMULATEX	(0x0fb000f0, 0x06a00030, emulate_rd12rn16rm0_rwflags_nopc,
+	DECODE_EMULATEX	(0x0fb000f0, 0x06a00030, PROBES_SATURATE,
 						 REGS(0, NOPC, 0, 0, NOPC)),
 
 	/* REV			cccc 0110 1011 xxxx xxxx xxxx 0011 xxxx */
 	/* REV16		cccc 0110 1011 xxxx xxxx xxxx 1011 xxxx */
 	/* RBIT			cccc 0110 1111 xxxx xxxx xxxx 0011 xxxx */
 	/* REVSH		cccc 0110 1111 xxxx xxxx xxxx 1011 xxxx */
-	DECODE_EMULATEX	(0x0fb00070, 0x06b00030, emulate_rd12rm0_noflags_nopc,
+	DECODE_EMULATEX	(0x0fb00070, 0x06b00030, PROBES_REV,
 						 REGS(0, NOPC, 0, 0, NOPC)),
 
 	/* ???			cccc 0110 0x00 xxxx xxxx xxxx xxx1 xxxx */
@@ -480,12 +480,12 @@ static const union decode_item arm_cccc_0110_____xxx1_table[] = {
 	/* UHSUB16		cccc 0110 0111 xxxx xxxx xxxx 0111 xxxx */
 	/* UHADD8		cccc 0110 0111 xxxx xxxx xxxx 1001 xxxx */
 	/* UHSUB8		cccc 0110 0111 xxxx xxxx xxxx 1111 xxxx */
-	DECODE_EMULATEX	(0x0f800010, 0x06000010, emulate_rd12rn16rm0_rwflags_nopc,
+	DECODE_EMULATEX	(0x0f800010, 0x06000010, PROBES_MMI,
 						 REGS(NOPC, NOPC, 0, 0, NOPC)),
 
 	/* PKHBT		cccc 0110 1000 xxxx xxxx xxxx x001 xxxx */
 	/* PKHTB		cccc 0110 1000 xxxx xxxx xxxx x101 xxxx */
-	DECODE_EMULATEX	(0x0ff00030, 0x06800010, emulate_rd12rn16rm0_rwflags_nopc,
+	DECODE_EMULATEX	(0x0ff00030, 0x06800010, PROBES_PACK,
 						 REGS(NOPC, NOPC, 0, 0, NOPC)),
 
 	/* ???			cccc 0110 1001 xxxx xxxx xxxx 0111 xxxx */
@@ -498,7 +498,7 @@ static const union decode_item arm_cccc_0110_____xxx1_table[] = {
 	/* UXTB16		cccc 0110 1100 1111 xxxx xxxx 0111 xxxx */
 	/* UXTB			cccc 0110 1110 1111 xxxx xxxx 0111 xxxx */
 	/* UXTH			cccc 0110 1111 1111 xxxx xxxx 0111 xxxx */
-	DECODE_EMULATEX	(0x0f8f00f0, 0x068f0070, emulate_rd12rm0_noflags_nopc,
+	DECODE_EMULATEX	(0x0f8f00f0, 0x068f0070, PROBES_EXTEND,
 						 REGS(0, NOPC, 0, 0, NOPC)),
 
 	/* SXTAB16		cccc 0110 1000 xxxx xxxx xxxx 0111 xxxx */
@@ -507,7 +507,7 @@ static const union decode_item arm_cccc_0110_____xxx1_table[] = {
 	/* UXTAB16		cccc 0110 1100 xxxx xxxx xxxx 0111 xxxx */
 	/* UXTAB		cccc 0110 1110 xxxx xxxx xxxx 0111 xxxx */
 	/* UXTAH		cccc 0110 1111 xxxx xxxx xxxx 0111 xxxx */
-	DECODE_EMULATEX	(0x0f8000f0, 0x06800070, emulate_rd12rn16rm0_rwflags_nopc,
+	DECODE_EMULATEX	(0x0f8000f0, 0x06800070, PROBES_EXTEND_ADD,
 						 REGS(NOPCX, NOPC, 0, 0, NOPC)),
 
 	DECODE_END
@@ -521,7 +521,7 @@ static const union decode_item arm_cccc_0111_____xxx1_table[] = {
 
 	/* SMLALD		cccc 0111 0100 xxxx xxxx xxxx 00x1 xxxx */
 	/* SMLSLD		cccc 0111 0100 xxxx xxxx xxxx 01x1 xxxx */
-	DECODE_EMULATEX	(0x0ff00090, 0x07400010, emulate_rdlo12rdhi16rn0rm8_rwflags_nopc,
+	DECODE_EMULATEX	(0x0ff00090, 0x07400010, PROBES_MUL_ADD_LONG,
 						 REGS(NOPC, NOPC, NOPC, 0, NOPC)),
 
 	/* SMUAD		cccc 0111 0000 xxxx 1111 xxxx 00x1 xxxx */
@@ -530,7 +530,7 @@ static const union decode_item arm_cccc_0111_____xxx1_table[] = {
 	/* SMMUL		cccc 0111 0101 xxxx 1111 xxxx 00x1 xxxx */
 	DECODE_OR	(0x0ff0f0d0, 0x0750f010),
 	/* USAD8		cccc 0111 1000 xxxx 1111 xxxx 0001 xxxx */
-	DECODE_EMULATEX	(0x0ff0f0f0, 0x0780f010, emulate_rd16rn12rm0rs8_rwflags_nopc,
+	DECODE_EMULATEX	(0x0ff0f0f0, 0x0780f010, PROBES_MUL_ADD,
 						 REGS(NOPC, 0, NOPC, 0, NOPC)),
 
 	/* SMLAD		cccc 0111 0000 xxxx xxxx xxxx 00x1 xxxx */
@@ -539,24 +539,24 @@ static const union decode_item arm_cccc_0111_____xxx1_table[] = {
 	/* SMMLA		cccc 0111 0101 xxxx xxxx xxxx 00x1 xxxx */
 	DECODE_OR	(0x0ff000d0, 0x07500010),
 	/* USADA8		cccc 0111 1000 xxxx xxxx xxxx 0001 xxxx */
-	DECODE_EMULATEX	(0x0ff000f0, 0x07800010, emulate_rd16rn12rm0rs8_rwflags_nopc,
+	DECODE_EMULATEX	(0x0ff000f0, 0x07800010, PROBES_MUL_ADD,
 						 REGS(NOPC, NOPCX, NOPC, 0, NOPC)),
 
 	/* SMMLS		cccc 0111 0101 xxxx xxxx xxxx 11x1 xxxx */
-	DECODE_EMULATEX	(0x0ff000d0, 0x075000d0, emulate_rd16rn12rm0rs8_rwflags_nopc,
+	DECODE_EMULATEX	(0x0ff000d0, 0x075000d0, PROBES_MUL_ADD,
 						 REGS(NOPC, NOPC, NOPC, 0, NOPC)),
 
 	/* SBFX			cccc 0111 101x xxxx xxxx xxxx x101 xxxx */
 	/* UBFX			cccc 0111 111x xxxx xxxx xxxx x101 xxxx */
-	DECODE_EMULATEX	(0x0fa00070, 0x07a00050, emulate_rd12rm0_noflags_nopc,
+	DECODE_EMULATEX	(0x0fa00070, 0x07a00050, PROBES_BITFIELD,
 						 REGS(0, NOPC, 0, 0, NOPC)),
 
 	/* BFC			cccc 0111 110x xxxx xxxx xxxx x001 1111 */
-	DECODE_EMULATEX	(0x0fe0007f, 0x07c0001f, emulate_rd12rm0_noflags_nopc,
+	DECODE_EMULATEX	(0x0fe0007f, 0x07c0001f, PROBES_BITFIELD,
 						 REGS(0, NOPC, 0, 0, 0)),
 
 	/* BFI			cccc 0111 110x xxxx xxxx xxxx x001 xxxx */
-	DECODE_EMULATEX	(0x0fe00070, 0x07c00010, emulate_rd12rm0_noflags_nopc,
+	DECODE_EMULATEX	(0x0fe00070, 0x07c00010, PROBES_BITFIELD,
 						 REGS(0, NOPC, 0, 0, NOPCX)),
 
 	DECODE_END
@@ -576,22 +576,22 @@ static const union decode_item arm_cccc_01xx_table[] = {
 
 	/* STR (immediate)	cccc 010x x0x0 xxxx xxxx xxxx xxxx xxxx */
 	/* STRB (immediate)	cccc 010x x1x0 xxxx xxxx xxxx xxxx xxxx */
-	DECODE_EMULATEX	(0x0e100000, 0x04000000, emulate_str,
+	DECODE_EMULATEX	(0x0e100000, 0x04000000, PROBES_STORE,
 						 REGS(NOPCWB, ANY, 0, 0, 0)),
 
 	/* LDR (immediate)	cccc 010x x0x1 xxxx xxxx xxxx xxxx xxxx */
 	/* LDRB (immediate)	cccc 010x x1x1 xxxx xxxx xxxx xxxx xxxx */
-	DECODE_EMULATEX	(0x0e100000, 0x04100000, emulate_ldr,
+	DECODE_EMULATEX	(0x0e100000, 0x04100000, PROBES_LOAD,
 						 REGS(NOPCWB, ANY, 0, 0, 0)),
 
 	/* STR (register)	cccc 011x x0x0 xxxx xxxx xxxx xxxx xxxx */
 	/* STRB (register)	cccc 011x x1x0 xxxx xxxx xxxx xxxx xxxx */
-	DECODE_EMULATEX	(0x0e100000, 0x06000000, emulate_str,
+	DECODE_EMULATEX	(0x0e100000, 0x06000000, PROBES_STORE,
 						 REGS(NOPCWB, ANY, 0, 0, NOPC)),
 
 	/* LDR (register)	cccc 011x x0x1 xxxx xxxx xxxx xxxx xxxx */
 	/* LDRB (register)	cccc 011x x1x1 xxxx xxxx xxxx xxxx xxxx */
-	DECODE_EMULATEX	(0x0e100000, 0x06100000, emulate_ldr,
+	DECODE_EMULATEX	(0x0e100000, 0x06100000, PROBES_LOAD,
 						 REGS(NOPCWB, ANY, 0, 0, NOPC)),
 
 	DECODE_END
@@ -602,7 +602,7 @@ static const union decode_item arm_cccc_100x_table[] = {
 
 	/* LDM			cccc 100x x0x1 xxxx xxxx xxxx xxxx xxxx */
 	/* STM			cccc 100x x0x0 xxxx xxxx xxxx xxxx xxxx */
-	DECODE_CUSTOM	(0x0e400000, 0x08000000, kprobe_decode_ldmstm),
+	DECODE_CUSTOM	(0x0e400000, 0x08000000, PROBES_LDMSTM),
 
 	/* STM (user registers)	cccc 100x x1x0 xxxx xxxx xxxx xxxx xxxx */
 	/* LDM (user registers)	cccc 100x x1x1 xxxx 0xxx xxxx xxxx xxxx */
@@ -682,7 +682,7 @@ const union decode_item kprobe_decode_arm_table[] = {
 
 	/* B			cccc 1010 xxxx xxxx xxxx xxxx xxxx xxxx */
 	/* BL			cccc 1011 xxxx xxxx xxxx xxxx xxxx xxxx */
-	DECODE_SIMULATE	(0x0e000000, 0x0a000000, simulate_bbl),
+	DECODE_SIMULATE	(0x0e000000, 0x0a000000, PROBES_BRANCH),
 
 	/*
 	 * Supervisor Call, and coprocessor instructions
@@ -723,9 +723,11 @@ static void __kprobes arm_singlestep(struct kprobe *p, struct pt_regs *regs)
  *   should also be very rare.
  */
 enum kprobe_insn __kprobes
-arm_kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi)
+arm_kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi,
+		       const union decode_action *actions)
 {
 	asi->insn_singlestep = arm_singlestep;
 	asi->insn_check_cc = kprobe_condition_checks[insn>>28];
-	return kprobe_decode_insn(insn, asi, kprobe_decode_arm_table, false);
+	return kprobe_decode_insn(insn, asi, kprobe_decode_arm_table, false,
+				  actions);
 }

arch/arm/kernel/probes-arm.h

@@ -15,24 +15,48 @@
 #ifndef _ARM_KERNEL_PROBES_ARM_H
 #define  _ARM_KERNEL_PROBES_ARM_H
 
+enum probes_arm_action {
+	PROBES_EMULATE_NONE,
+	PROBES_SIMULATE_NOP,
+	PROBES_PRELOAD_IMM,
+	PROBES_PRELOAD_REG,
+	PROBES_BRANCH_IMM,
+	PROBES_BRANCH_REG,
+	PROBES_MRS,
+	PROBES_CLZ,
+	PROBES_SATURATING_ARITHMETIC,
+	PROBES_MUL1,
+	PROBES_MUL2,
+	PROBES_SWP,
+	PROBES_LDRSTRD,
+	PROBES_LOAD,
+	PROBES_STORE,
+	PROBES_LOAD_EXTRA,
+	PROBES_STORE_EXTRA,
+	PROBES_MOV_IP_SP,
+	PROBES_DATA_PROCESSING_REG,
+	PROBES_DATA_PROCESSING_IMM,
+	PROBES_MOV_HALFWORD,
+	PROBES_SEV,
+	PROBES_WFE,
+	PROBES_SATURATE,
+	PROBES_REV,
+	PROBES_MMI,
+	PROBES_PACK,
+	PROBES_EXTEND,
+	PROBES_EXTEND_ADD,
+	PROBES_MUL_ADD_LONG,
+	PROBES_MUL_ADD,
+	PROBES_BITFIELD,
+	PROBES_BRANCH,
+	PROBES_LDMSTM,
+	NUM_PROBES_ARM_ACTIONS
+};
+
 void __kprobes simulate_bbl(struct kprobe *p, struct pt_regs *regs);
 void __kprobes simulate_blx1(struct kprobe *p, struct pt_regs *regs);
 void __kprobes simulate_blx2bx(struct kprobe *p, struct pt_regs *regs);
 void __kprobes simulate_mrs(struct kprobe *p, struct pt_regs *regs);
 void __kprobes simulate_mov_ipsp(struct kprobe *p, struct pt_regs *regs);
 
-void __kprobes emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs);
-void __kprobes emulate_ldr(struct kprobe *p, struct pt_regs *regs);
-void __kprobes emulate_str(struct kprobe *p, struct pt_regs *regs);
-void __kprobes emulate_rd12rn16rm0rs8_rwflags(struct kprobe *p,
-	struct pt_regs *regs);
-void __kprobes emulate_rd12rn16rm0_rwflags_nopc(struct kprobe *p,
-	struct pt_regs *regs);
-void __kprobes emulate_rd16rn12rm0rs8_rwflags_nopc(struct kprobe *p,
-	struct pt_regs *regs);
-void __kprobes emulate_rd12rm0_noflags_nopc(struct kprobe *p,
-	struct pt_regs *regs);
-void __kprobes emulate_rdlo12rdhi16rn0rm8_rwflags_nopc(struct kprobe *p,
-	struct pt_regs *regs);
-
 #endif

arch/arm/kernel/probes-thumb.h

@@ -27,55 +27,61 @@
  */
 #define current_cond(cpsr)	((cpsr >> 12) & 0xf)
 
-void __kprobes t16_simulate_bxblx(struct kprobe *p, struct pt_regs *regs);
-void __kprobes t16_simulate_ldr_literal(struct kprobe *p, struct pt_regs *regs);
-void __kprobes t16_simulate_ldrstr_sp_relative(struct kprobe *p,
-		struct pt_regs *regs);
-void __kprobes t16_simulate_reladr(struct kprobe *p, struct pt_regs *regs);
-void __kprobes t16_simulate_add_sp_imm(struct kprobe *p, struct pt_regs *regs);
-void __kprobes t16_simulate_cbz(struct kprobe *p, struct pt_regs *regs);
-void __kprobes t16_simulate_it(struct kprobe *p, struct pt_regs *regs);
-void __kprobes t16_singlestep_it(struct kprobe *p, struct pt_regs *regs);
-enum kprobe_insn __kprobes t16_decode_it(kprobe_opcode_t insn,
-	struct arch_specific_insn *asi);
-void __kprobes t16_simulate_cond_branch(struct kprobe *p, struct pt_regs *regs);
-enum kprobe_insn __kprobes t16_decode_cond_branch(kprobe_opcode_t insn,
-	struct arch_specific_insn *asi);
-void __kprobes t16_simulate_branch(struct kprobe *p, struct pt_regs *regs);
-void __kprobes t16_emulate_loregs_rwflags(struct kprobe *p,
-	struct pt_regs *regs);
-void __kprobes t16_emulate_loregs_noitrwflags(struct kprobe *p,
-	struct pt_regs *regs);
-void __kprobes t16_emulate_hiregs(struct kprobe *p, struct pt_regs *regs);
-enum kprobe_insn __kprobes t16_decode_hiregs(kprobe_opcode_t insn,
-	struct arch_specific_insn *asi);
-void __kprobes t16_emulate_push(struct kprobe *p, struct pt_regs *regs);
-enum kprobe_insn __kprobes t16_decode_push(kprobe_opcode_t insn,
-	struct arch_specific_insn *asi);
-void __kprobes t16_emulate_pop_nopc(struct kprobe *p, struct pt_regs *regs);
-void __kprobes t16_emulate_pop_pc(struct kprobe *p, struct pt_regs *regs);
-enum kprobe_insn __kprobes t16_decode_pop(kprobe_opcode_t insn,
-	struct arch_specific_insn *asi);
+enum probes_t32_action {
+	PROBES_T32_EMULATE_NONE,
+	PROBES_T32_SIMULATE_NOP,
+	PROBES_T32_LDMSTM,
+	PROBES_T32_LDRDSTRD,
+	PROBES_T32_TABLE_BRANCH,
+	PROBES_T32_TST,
+	PROBES_T32_CMP,
+	PROBES_T32_MOV,
+	PROBES_T32_ADDSUB,
+	PROBES_T32_LOGICAL,
+	PROBES_T32_ADDWSUBW_PC,
+	PROBES_T32_ADDWSUBW,
+	PROBES_T32_MOVW,
+	PROBES_T32_SAT,
+	PROBES_T32_BITFIELD,
+	PROBES_T32_SEV,
+	PROBES_T32_WFE,
+	PROBES_T32_MRS,
+	PROBES_T32_BRANCH_COND,
+	PROBES_T32_BRANCH,
+	PROBES_T32_PLDI,
+	PROBES_T32_LDR_LIT,
+	PROBES_T32_LDRSTR,
+	PROBES_T32_SIGN_EXTEND,
+	PROBES_T32_MEDIA,
+	PROBES_T32_REVERSE,
+	PROBES_T32_MUL_ADD,
+	PROBES_T32_MUL_ADD2,
+	PROBES_T32_MUL_ADD_LONG,
+	NUM_PROBES_T32_ACTIONS
+};
 
-void __kprobes t32_simulate_table_branch(struct kprobe *p,
-	struct pt_regs *regs);
-void __kprobes t32_simulate_mrs(struct kprobe *p, struct pt_regs *regs);
-void __kprobes t32_simulate_cond_branch(struct kprobe *p, struct pt_regs *regs);
-enum kprobe_insn __kprobes t32_decode_cond_branch(kprobe_opcode_t insn,
-	struct arch_specific_insn *asi);
-void __kprobes t32_simulate_branch(struct kprobe *p, struct pt_regs *regs);
-void __kprobes t32_simulate_ldr_literal(struct kprobe *p, struct pt_regs *regs);
-enum kprobe_insn __kprobes t32_decode_ldmstm(kprobe_opcode_t insn,
-	struct arch_specific_insn *asi);
-void __kprobes t32_emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs);
-void __kprobes t32_emulate_ldrstr(struct kprobe *p, struct pt_regs *regs);
-void __kprobes t32_emulate_rd8rn16rm0_rwflags(struct kprobe *p,
-	struct pt_regs *regs);
-void __kprobes t32_emulate_rd8pc16_noflags(struct kprobe *p,
-	struct pt_regs *regs);
-void __kprobes t32_emulate_rd8rn16_noflags(struct kprobe *p,
-	struct pt_regs *regs);
-void __kprobes t32_emulate_rdlo12rdhi8rn16rm0_noflags(struct kprobe *p,
-	struct pt_regs *regs);
+enum probes_t16_action {
+	PROBES_T16_ADD_SP,
+	PROBES_T16_CBZ,
+	PROBES_T16_SIGN_EXTEND,
+	PROBES_T16_PUSH,
+	PROBES_T16_POP,
+	PROBES_T16_SEV,
+	PROBES_T16_WFE,
+	PROBES_T16_IT,
+	PROBES_T16_CMP,
+	PROBES_T16_ADDSUB,
+	PROBES_T16_LOGICAL,
+	PROBES_T16_BLX,
+	PROBES_T16_HIREGOPS,
+	PROBES_T16_LDR_LIT,
+	PROBES_T16_LDRHSTRH,
+	PROBES_T16_LDRSTR,
+	PROBES_T16_ADR,
+	PROBES_T16_LDMSTM,
+	PROBES_T16_BRANCH_COND,
+	PROBES_T16_BRANCH,
+	NUM_PROBES_T16_ACTIONS
+};
 
 #endif

arch/arm/kernel/probes.c

@@ -381,7 +381,8 @@ static const int decode_struct_sizes[NUM_DECODE_TYPES] = {
  */
 int __kprobes
 kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi,
-		   const union decode_item *table, bool thumb)
+		   const union decode_item *table, bool thumb,
+		   const union decode_action *actions)
 {
 	const struct decode_header *h = (struct decode_header *)table;
 	const struct decode_header *next;
@@ -415,18 +416,18 @@ kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi,
 
 		case DECODE_TYPE_CUSTOM: {
 			struct decode_custom *d = (struct decode_custom *)h;
-			return (*d->decoder.decoder)(insn, asi);
+			return actions[d->decoder.action].decoder(insn, asi, h);
 		}
 
 		case DECODE_TYPE_SIMULATE: {
 			struct decode_simulate *d = (struct decode_simulate *)h;
-			asi->insn_handler = d->handler.handler;
+			asi->insn_handler = actions[d->handler.action].handler;
 			return INSN_GOOD_NO_SLOT;
 		}
 
 		case DECODE_TYPE_EMULATE: {
 			struct decode_emulate *d = (struct decode_emulate *)h;
-			asi->insn_handler = d->handler.handler;
+			asi->insn_handler = actions[d->handler.action].handler;
 			set_emulated_insn(insn, asi, thumb);
 			return INSN_GOOD;
 		}

arch/arm/kernel/probes.h

@@ -133,7 +133,8 @@ void __kprobes kprobe_simulate_nop(struct kprobe *p, struct pt_regs *regs);
 void __kprobes kprobe_emulate_none(struct kprobe *p, struct pt_regs *regs);
 
 enum kprobe_insn __kprobes
-kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi);
+kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi,
+		const struct decode_header *h);
 
 /*
  * Test if load/store instructions writeback the address register.
@@ -160,7 +161,7 @@ kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi);
  *	{.bits = _type},
  *	{.bits = _mask},
  *	{.bits = _value},
- *	{.handler = _handler},
+ *	{.action = _handler},
  *
  * Initialising a specified member of the union means that the compiler
  * will produce a warning if the argument is of an incorrect type.
@@ -173,19 +174,23 @@ kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi);
  *	Instruction decoding jumps to parsing the new sub-table 'table'.
  *
  * DECODE_CUSTOM(mask, value, decoder)
- *	The custom function 'decoder' is called to the complete decoding
- *	of an instruction.
+ *	The value of 'decoder' is used as an index into the array of
+ *	action functions, and the retrieved decoder function is invoked
+ *	to complete decoding of the instruction.
  *
  * DECODE_SIMULATE(mask, value, handler)
- *	Set the probes instruction handler to 'handler', this will be used
- *	to simulate the instruction when the probe is hit. Decoding returns
- *	with INSN_GOOD_NO_SLOT.
+ *	The probes instruction handler is set to the value found by
+ *	indexing into the action array using the value of 'handler'. This
+ *	will be used to simulate the instruction when the probe is hit.
+ *	Decoding returns with INSN_GOOD_NO_SLOT.
  *
  * DECODE_EMULATE(mask, value, handler)
- *	Set the probes instruction handler to 'handler', this will be used
- *	to emulate the instruction when the probe is hit. The modified
- *	instruction (see below) is placed in the probes instruction slot so it
- *	may be called by the emulation code. Decoding returns with INSN_GOOD.
+ *	The probes instruction handler is set to the value found by
+ *	indexing into the action array using the value of 'handler'. This
+ *	will be used to emulate the instruction when the probe is hit. The
+ *	modified instruction (see below) is placed in the probes instruction
+ *	slot so it may be called by the emulation code. Decoding returns
+ *	with INSN_GOOD.
  *
  * DECODE_REJECT(mask, value)
  *	Instruction decoding fails with INSN_REJECTED
@@ -238,7 +243,7 @@ kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi);
  * Here is a real example which matches ARM instructions of the form
  * "AND <Rd>,<Rn>,<Rm>,<shift> <Rs>"
  *
- *	DECODE_EMULATEX	(0x0e000090, 0x00000010, emulate_rd12rn16rm0rs8_rwflags,
+ *	DECODE_EMULATEX	(0x0e000090, 0x00000010, PROBES_DATA_PROCESSING_REG,
  *						 REGS(ANY, ANY, NOPC, 0, ANY)),
  *						      ^    ^    ^        ^
  *						      Rn   Rd   Rs       Rm
@@ -249,7 +254,8 @@ kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi);
  * Decoding the instruction "AND R4, R5, R6, ASL R7" will be accepted and the
  * instruction will be modified to "AND R0, R2, R3, ASL R1" and then placed into
  * the kprobes instruction slot. This can then be called later by the handler
- * function emulate_rd12rn16rm0rs8_rwflags in order to simulate the instruction.
+ * function emulate_rd12rn16rm0rs8_rwflags (a pointer to which is retrieved from
+ * the indicated slot in the action array), in order to simulate the instruction.
  */
 
 enum decode_type {
@@ -298,10 +304,17 @@ enum decode_reg_type {
 union decode_item {
 	u32			bits;
 	const union decode_item	*table;
-	kprobe_insn_handler_t	*handler;
-	kprobe_decode_insn_t	*decoder;
+	int			action;
 };
 
+typedef enum kprobe_insn (probes_custom_decode_t)(kprobe_opcode_t,
+						  struct arch_specific_insn *,
+						  const struct decode_header *);
+
+union decode_action {
+	kprobe_insn_handler_t	*handler;
+	probes_custom_decode_t	*decoder;
+};
 
 #define DECODE_END			\
 	{.bits = DECODE_TYPE_END}
@@ -336,7 +349,7 @@ struct decode_custom {
 
 #define DECODE_CUSTOM(_mask, _value, _decoder)			\
 	DECODE_HEADER(DECODE_TYPE_CUSTOM, _mask, _value, 0),	\
-	{.decoder = (_decoder)}
+	{.action = (_decoder)}
 
 
 struct decode_simulate {
@@ -346,7 +359,7 @@ struct decode_simulate {
 
 #define DECODE_SIMULATEX(_mask, _value, _handler, _regs)		\
 	DECODE_HEADER(DECODE_TYPE_SIMULATE, _mask, _value, _regs),	\
-	{.handler = (_handler)}
+	{.action = (_handler)}
 
 #define DECODE_SIMULATE(_mask, _value, _handler)	\
 	DECODE_SIMULATEX(_mask, _value, _handler, 0)
@@ -359,7 +372,7 @@ struct decode_emulate {
 
 #define DECODE_EMULATEX(_mask, _value, _handler, _regs)			\
 	DECODE_HEADER(DECODE_TYPE_EMULATE, _mask, _value, _regs),	\
-	{.handler = (_handler)}
+	{.action = (_handler)}
 
 #define DECODE_EMULATE(_mask, _value, _handler)		\
 	DECODE_EMULATEX(_mask, _value, _handler, 0)
@@ -384,14 +397,18 @@ struct decode_reject {
 #ifdef CONFIG_THUMB2_KERNEL
 extern const union decode_item kprobe_decode_thumb16_table[];
 extern const union decode_item kprobe_decode_thumb32_table[];
+extern const union decode_action kprobes_t32_actions[];
+extern const union decode_action kprobes_t16_actions[];
 #else
 extern const union decode_item kprobe_decode_arm_table[];
+extern const union decode_action kprobes_arm_actions[];
 #endif
 
 extern kprobe_check_cc * const kprobe_condition_checks[16];
 
 
 int kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi,
-		       const union decode_item *table, bool thumb16);
+		       const union decode_item *table, bool thumb16,
+		       const union decode_action *actions);
 
 #endif