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: David A. Long <dave.long@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>

1 files changed, 49 insertions, 8 deletions

diff --git a/arch/arm/kernel/kprobes-arm.c b/arch/arm/kernel/kprobes-arm.c
index a1d0a8f00f9e..8ebd84c48867 100644
--- a/arch/arm/kernel/kprobes-arm.c
+++ b/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}
+};