Commit 602cd260 authored by David A. Long's avatar David A. Long

ARM: Add an emulate flag to the kprobes/uprobes instruction decode functions

Add an emulate flag into the instruction interpreter, primarily for uprobes
support.
Signed-off-by: default avatarDavid A. Long <dave.long@linaro.org>
Acked-by: default avatarJon Medhurst <tixy@linaro.org>
parent 47e190fa
...@@ -89,7 +89,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) ...@@ -89,7 +89,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
p->opcode = insn; p->opcode = insn;
p->ainsn.insn = tmp_insn; p->ainsn.insn = tmp_insn;
switch ((*decode_insn)(insn, &p->ainsn, actions)) { switch ((*decode_insn)(insn, &p->ainsn, true, actions)) {
case INSN_REJECTED: /* not supported */ case INSN_REJECTED: /* not supported */
return -EINVAL; return -EINVAL;
......
...@@ -35,6 +35,7 @@ kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi, ...@@ -35,6 +35,7 @@ kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi,
typedef enum probes_insn (kprobe_decode_insn_t)(probes_opcode_t, typedef enum probes_insn (kprobe_decode_insn_t)(probes_opcode_t,
struct arch_specific_insn *, struct arch_specific_insn *,
bool,
const union decode_action *); const union decode_action *);
#ifdef CONFIG_THUMB2_KERNEL #ifdef CONFIG_THUMB2_KERNEL
......
...@@ -725,10 +725,10 @@ static void __kprobes arm_singlestep(probes_opcode_t insn, ...@@ -725,10 +725,10 @@ static void __kprobes arm_singlestep(probes_opcode_t insn,
*/ */
enum probes_insn __kprobes enum probes_insn __kprobes
arm_probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi, arm_probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi,
const union decode_action *actions) bool emulate, const union decode_action *actions)
{ {
asi->insn_singlestep = arm_singlestep; asi->insn_singlestep = arm_singlestep;
asi->insn_check_cc = probes_condition_checks[insn>>28]; asi->insn_check_cc = probes_condition_checks[insn>>28];
return probes_decode_insn(insn, asi, probes_decode_arm_table, false, return probes_decode_insn(insn, asi, probes_decode_arm_table, false,
actions); emulate, actions);
} }
...@@ -67,7 +67,7 @@ void __kprobes simulate_mov_ipsp(probes_opcode_t opcode, ...@@ -67,7 +67,7 @@ void __kprobes simulate_mov_ipsp(probes_opcode_t opcode,
extern const union decode_item probes_decode_arm_table[]; extern const union decode_item probes_decode_arm_table[];
enum probes_insn arm_probes_decode_insn(probes_opcode_t, enum probes_insn arm_probes_decode_insn(probes_opcode_t,
struct arch_specific_insn *, struct arch_specific_insn *, bool emulate,
const union decode_action *actions); const union decode_action *actions);
#endif #endif
...@@ -863,20 +863,20 @@ static void __kprobes thumb32_singlestep(probes_opcode_t opcode, ...@@ -863,20 +863,20 @@ static void __kprobes thumb32_singlestep(probes_opcode_t opcode,
enum probes_insn __kprobes enum probes_insn __kprobes
thumb16_probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi, thumb16_probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi,
const union decode_action *actions) bool emulate, const union decode_action *actions)
{ {
asi->insn_singlestep = thumb16_singlestep; asi->insn_singlestep = thumb16_singlestep;
asi->insn_check_cc = thumb_check_cc; asi->insn_check_cc = thumb_check_cc;
return probes_decode_insn(insn, asi, probes_decode_thumb16_table, true, return probes_decode_insn(insn, asi, probes_decode_thumb16_table, true,
actions); emulate, actions);
} }
enum probes_insn __kprobes enum probes_insn __kprobes
thumb32_probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi, thumb32_probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi,
const union decode_action *actions) bool emulate, const union decode_action *actions)
{ {
asi->insn_singlestep = thumb32_singlestep; asi->insn_singlestep = thumb32_singlestep;
asi->insn_check_cc = thumb_check_cc; asi->insn_check_cc = thumb_check_cc;
return probes_decode_insn(insn, asi, probes_decode_thumb32_table, true, return probes_decode_insn(insn, asi, probes_decode_thumb32_table, true,
actions); emulate, actions);
} }
...@@ -89,9 +89,9 @@ extern const union decode_item probes_decode_thumb16_table[]; ...@@ -89,9 +89,9 @@ extern const union decode_item probes_decode_thumb16_table[];
enum probes_insn __kprobes enum probes_insn __kprobes
thumb16_probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi, thumb16_probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi,
const union decode_action *actions); bool emulate, const union decode_action *actions);
enum probes_insn __kprobes enum probes_insn __kprobes
thumb32_probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi, thumb32_probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi,
const union decode_action *actions); bool emulate, const union decode_action *actions);
#endif #endif
...@@ -257,7 +257,7 @@ set_emulated_insn(probes_opcode_t insn, struct arch_specific_insn *asi, ...@@ -257,7 +257,7 @@ set_emulated_insn(probes_opcode_t insn, struct arch_specific_insn *asi,
* non-zero value, the corresponding nibble in pinsn is validated and modified * non-zero value, the corresponding nibble in pinsn is validated and modified
* according to the type. * according to the type.
*/ */
static bool __kprobes decode_regs(probes_opcode_t *pinsn, u32 regs) static bool __kprobes decode_regs(probes_opcode_t *pinsn, u32 regs, bool modify)
{ {
probes_opcode_t insn = *pinsn; probes_opcode_t insn = *pinsn;
probes_opcode_t mask = 0xf; /* Start at least significant nibble */ probes_opcode_t mask = 0xf; /* Start at least significant nibble */
...@@ -323,7 +323,9 @@ static bool __kprobes decode_regs(probes_opcode_t *pinsn, u32 regs) ...@@ -323,7 +323,9 @@ static bool __kprobes decode_regs(probes_opcode_t *pinsn, u32 regs)
insn |= new_bits & mask; insn |= new_bits & mask;
} }
if (modify)
*pinsn = insn; *pinsn = insn;
return true; return true;
reject: reject:
...@@ -385,12 +387,13 @@ static const int decode_struct_sizes[NUM_DECODE_TYPES] = { ...@@ -385,12 +387,13 @@ static const int decode_struct_sizes[NUM_DECODE_TYPES] = {
int __kprobes int __kprobes
probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi, probes_decode_insn(probes_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) bool emulate, const union decode_action *actions)
{ {
const struct decode_header *h = (struct decode_header *)table; const struct decode_header *h = (struct decode_header *)table;
const struct decode_header *next; const struct decode_header *next;
bool matched = false; bool matched = false;
if (emulate)
insn = prepare_emulated_insn(insn, asi, thumb); insn = prepare_emulated_insn(insn, asi, thumb);
for (;; h = next) { for (;; h = next) {
...@@ -406,7 +409,7 @@ probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi, ...@@ -406,7 +409,7 @@ probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi,
if (!matched && (insn & h->mask.bits) != h->value.bits) if (!matched && (insn & h->mask.bits) != h->value.bits)
continue; continue;
if (!decode_regs(&insn, regs)) if (!decode_regs(&insn, regs, emulate))
return INSN_REJECTED; return INSN_REJECTED;
switch (type) { switch (type) {
...@@ -430,6 +433,11 @@ probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi, ...@@ -430,6 +433,11 @@ probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi,
case DECODE_TYPE_EMULATE: { case DECODE_TYPE_EMULATE: {
struct decode_emulate *d = (struct decode_emulate *)h; struct decode_emulate *d = (struct decode_emulate *)h;
if (!emulate)
return actions[d->handler.action].decoder(insn,
asi, h);
asi->insn_handler = actions[d->handler.action].handler; asi->insn_handler = actions[d->handler.action].handler;
set_emulated_insn(insn, asi, thumb); set_emulated_insn(insn, asi, thumb);
return INSN_GOOD; return INSN_GOOD;
......
...@@ -401,7 +401,7 @@ probes_insn_handler_t probes_emulate_none; ...@@ -401,7 +401,7 @@ probes_insn_handler_t probes_emulate_none;
int __kprobes int __kprobes
probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi, probes_decode_insn(probes_opcode_t insn, struct arch_specific_insn *asi,
const union decode_item *table, bool thumb, const union decode_item *table, bool thumb, bool emulate,
const union decode_action *actions); const union decode_action *actions);
#endif #endif
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