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authorWang Nan <wangnan0@huawei.com>2015-01-05 19:29:18 +0800
committerJon Medhurst <tixy@linaro.org>2015-01-09 09:36:51 +0000
commit83803d97dae1eaf6850a45ef8ee179cc66e147dc (patch)
treee2b1124f1c7896dcadb2af471a0570b019dad551 /arch/arm
parent832607e79d7423c67ef8a3de8dfa3d25b5b0bf86 (diff)
ARM: kprobes: introduces checker
This patch introdces 'checker' to decoding phase, and calls checkers when instruction decoding. This allows further decoding for specific instructions. This patch introduces a stub call of checkers in kprobe arch_prepare_kprobe() as an example and for further expansion. Signed-off-by: Wang Nan <wangnan0@huawei.com> Reviewed-by: Jon Medhurst <tixy@linaro.org> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jon Medhurst <tixy@linaro.org>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/probes/decode-arm.c5
-rw-r--r--arch/arm/probes/decode-arm.h3
-rw-r--r--arch/arm/probes/decode-thumb.c10
-rw-r--r--arch/arm/probes/decode-thumb.h6
-rw-r--r--arch/arm/probes/decode.c60
-rw-r--r--arch/arm/probes/decode.h11
-rw-r--r--arch/arm/probes/kprobes/actions-arm.c2
-rw-r--r--arch/arm/probes/kprobes/actions-thumb.c3
-rw-r--r--arch/arm/probes/kprobes/core.c6
-rw-r--r--arch/arm/probes/kprobes/core.h7
-rw-r--r--arch/arm/probes/uprobes/core.c2
11 files changed, 95 insertions, 20 deletions
diff --git a/arch/arm/probes/decode-arm.c b/arch/arm/probes/decode-arm.c
index 04114f74a2d2..f72c33a2dcfb 100644
--- a/arch/arm/probes/decode-arm.c
+++ b/arch/arm/probes/decode-arm.c
@@ -726,10 +726,11 @@ static void __kprobes arm_singlestep(probes_opcode_t insn,
*/
enum probes_insn __kprobes
arm_probes_decode_insn(probes_opcode_t insn, struct arch_probes_insn *asi,
- bool emulate, const union decode_action *actions)
+ bool emulate, const union decode_action *actions,
+ const struct decode_checker *checkers[])
{
asi->insn_singlestep = arm_singlestep;
asi->insn_check_cc = probes_condition_checks[insn>>28];
return probes_decode_insn(insn, asi, probes_decode_arm_table, false,
- emulate, actions);
+ emulate, actions, checkers);
}
diff --git a/arch/arm/probes/decode-arm.h b/arch/arm/probes/decode-arm.h
index cb0b26331930..b3b80f6d414b 100644
--- a/arch/arm/probes/decode-arm.h
+++ b/arch/arm/probes/decode-arm.h
@@ -68,6 +68,7 @@ extern const union decode_item probes_decode_arm_table[];
enum probes_insn arm_probes_decode_insn(probes_opcode_t,
struct arch_probes_insn *, bool emulate,
- const union decode_action *actions);
+ const union decode_action *actions,
+ const struct decode_checker *checkers[]);
#endif
diff --git a/arch/arm/probes/decode-thumb.c b/arch/arm/probes/decode-thumb.c
index 2f0453a895dc..985e7dd4cac6 100644
--- a/arch/arm/probes/decode-thumb.c
+++ b/arch/arm/probes/decode-thumb.c
@@ -863,20 +863,22 @@ static void __kprobes thumb32_singlestep(probes_opcode_t opcode,
enum probes_insn __kprobes
thumb16_probes_decode_insn(probes_opcode_t insn, struct arch_probes_insn *asi,
- bool emulate, const union decode_action *actions)
+ bool emulate, const union decode_action *actions,
+ const struct decode_checker *checkers[])
{
asi->insn_singlestep = thumb16_singlestep;
asi->insn_check_cc = thumb_check_cc;
return probes_decode_insn(insn, asi, probes_decode_thumb16_table, true,
- emulate, actions);
+ emulate, actions, checkers);
}
enum probes_insn __kprobes
thumb32_probes_decode_insn(probes_opcode_t insn, struct arch_probes_insn *asi,
- bool emulate, const union decode_action *actions)
+ bool emulate, const union decode_action *actions,
+ const struct decode_checker *checkers[])
{
asi->insn_singlestep = thumb32_singlestep;
asi->insn_check_cc = thumb_check_cc;
return probes_decode_insn(insn, asi, probes_decode_thumb32_table, true,
- emulate, actions);
+ emulate, actions, checkers);
}
diff --git a/arch/arm/probes/decode-thumb.h b/arch/arm/probes/decode-thumb.h
index 039013c7131d..8457add0a2d8 100644
--- a/arch/arm/probes/decode-thumb.h
+++ b/arch/arm/probes/decode-thumb.h
@@ -91,9 +91,11 @@ extern const union decode_item probes_decode_thumb16_table[];
enum probes_insn __kprobes
thumb16_probes_decode_insn(probes_opcode_t insn, struct arch_probes_insn *asi,
- bool emulate, const union decode_action *actions);
+ bool emulate, const union decode_action *actions,
+ const struct decode_checker *checkers[]);
enum probes_insn __kprobes
thumb32_probes_decode_insn(probes_opcode_t insn, struct arch_probes_insn *asi,
- bool emulate, const union decode_action *actions);
+ bool emulate, const union decode_action *actions,
+ const struct decode_checker *checkers[]);
#endif
diff --git a/arch/arm/probes/decode.c b/arch/arm/probes/decode.c
index 3b05d5742359..c7d442018902 100644
--- a/arch/arm/probes/decode.c
+++ b/arch/arm/probes/decode.c
@@ -342,6 +342,31 @@ static const int decode_struct_sizes[NUM_DECODE_TYPES] = {
[DECODE_TYPE_REJECT] = sizeof(struct decode_reject)
};
+static int run_checkers(const struct decode_checker *checkers[],
+ int action, probes_opcode_t insn,
+ struct arch_probes_insn *asi,
+ const struct decode_header *h)
+{
+ const struct decode_checker **p;
+
+ if (!checkers)
+ return INSN_GOOD;
+
+ p = checkers;
+ while (*p != NULL) {
+ int retval;
+ probes_check_t *checker_func = (*p)[action].checker;
+
+ retval = INSN_GOOD;
+ if (checker_func)
+ retval = checker_func(insn, asi, h);
+ if (retval == INSN_REJECTED)
+ return retval;
+ p++;
+ }
+ return INSN_GOOD;
+}
+
/*
* probes_decode_insn operates on data tables in order to decode an ARM
* architecture instruction onto which a kprobe has been placed.
@@ -388,11 +413,17 @@ static const int decode_struct_sizes[NUM_DECODE_TYPES] = {
int __kprobes
probes_decode_insn(probes_opcode_t insn, struct arch_probes_insn *asi,
const union decode_item *table, bool thumb,
- bool emulate, const union decode_action *actions)
+ bool emulate, const union decode_action *actions,
+ const struct decode_checker *checkers[])
{
const struct decode_header *h = (struct decode_header *)table;
const struct decode_header *next;
bool matched = false;
+ /*
+ * @insn can be modified by decode_regs. Save its original
+ * value for checkers.
+ */
+ probes_opcode_t origin_insn = insn;
if (emulate)
insn = prepare_emulated_insn(insn, asi, thumb);
@@ -422,24 +453,41 @@ probes_decode_insn(probes_opcode_t insn, struct arch_probes_insn *asi,
}
case DECODE_TYPE_CUSTOM: {
+ int err;
struct decode_custom *d = (struct decode_custom *)h;
- return actions[d->decoder.action].decoder(insn, asi, h);
+ int action = d->decoder.action;
+
+ err = run_checkers(checkers, action, origin_insn, asi, h);
+ if (err == INSN_REJECTED)
+ return INSN_REJECTED;
+ return actions[action].decoder(insn, asi, h);
}
case DECODE_TYPE_SIMULATE: {
+ int err;
struct decode_simulate *d = (struct decode_simulate *)h;
- asi->insn_handler = actions[d->handler.action].handler;
+ int action = d->handler.action;
+
+ err = run_checkers(checkers, action, origin_insn, asi, h);
+ if (err == INSN_REJECTED)
+ return INSN_REJECTED;
+ asi->insn_handler = actions[action].handler;
return INSN_GOOD_NO_SLOT;
}
case DECODE_TYPE_EMULATE: {
+ int err;
struct decode_emulate *d = (struct decode_emulate *)h;
+ int action = d->handler.action;
+
+ err = run_checkers(checkers, action, origin_insn, asi, h);
+ if (err == INSN_REJECTED)
+ return INSN_REJECTED;
if (!emulate)
- return actions[d->handler.action].decoder(insn,
- asi, h);
+ return actions[action].decoder(insn, asi, h);
- asi->insn_handler = actions[d->handler.action].handler;
+ asi->insn_handler = actions[action].handler;
set_emulated_insn(insn, asi, thumb);
return INSN_GOOD;
}
diff --git a/arch/arm/probes/decode.h b/arch/arm/probes/decode.h
index 1d0b53169080..f9b08ba7fe73 100644
--- a/arch/arm/probes/decode.h
+++ b/arch/arm/probes/decode.h
@@ -314,6 +314,14 @@ union decode_action {
probes_custom_decode_t *decoder;
};
+typedef enum probes_insn (probes_check_t)(probes_opcode_t,
+ struct arch_probes_insn *,
+ const struct decode_header *);
+
+struct decode_checker {
+ probes_check_t *checker;
+};
+
#define DECODE_END \
{.bits = DECODE_TYPE_END}
@@ -402,6 +410,7 @@ probes_insn_handler_t probes_emulate_none;
int __kprobes
probes_decode_insn(probes_opcode_t insn, struct arch_probes_insn *asi,
const union decode_item *table, bool thumb, bool emulate,
- const union decode_action *actions);
+ const union decode_action *actions,
+ const struct decode_checker **checkers);
#endif
diff --git a/arch/arm/probes/kprobes/actions-arm.c b/arch/arm/probes/kprobes/actions-arm.c
index 2206f2d80c76..fbd93a9ada75 100644
--- a/arch/arm/probes/kprobes/actions-arm.c
+++ b/arch/arm/probes/kprobes/actions-arm.c
@@ -339,3 +339,5 @@ const union decode_action kprobes_arm_actions[NUM_PROBES_ARM_ACTIONS] = {
[PROBES_BRANCH] = {.handler = simulate_bbl},
[PROBES_LDMSTM] = {.decoder = kprobe_decode_ldmstm}
};
+
+const struct decode_checker *kprobes_arm_checkers[] = {NULL};
diff --git a/arch/arm/probes/kprobes/actions-thumb.c b/arch/arm/probes/kprobes/actions-thumb.c
index 6c4e60b62826..2796121fe90e 100644
--- a/arch/arm/probes/kprobes/actions-thumb.c
+++ b/arch/arm/probes/kprobes/actions-thumb.c
@@ -664,3 +664,6 @@ const union decode_action kprobes_t32_actions[NUM_PROBES_T32_ACTIONS] = {
[PROBES_T32_MUL_ADD_LONG] = {
.handler = t32_emulate_rdlo12rdhi8rn16rm0_noflags},
};
+
+const struct decode_checker *kprobes_t32_checkers[] = {NULL};
+const struct decode_checker *kprobes_t16_checkers[] = {NULL};
diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c
index 701f49d74c35..74f3dc3ac212 100644
--- a/arch/arm/probes/kprobes/core.c
+++ b/arch/arm/probes/kprobes/core.c
@@ -61,6 +61,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
kprobe_decode_insn_t *decode_insn;
const union decode_action *actions;
int is;
+ const struct decode_checker **checkers;
if (in_exception_text(addr))
return -EINVAL;
@@ -74,9 +75,11 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
insn = __opcode_thumb32_compose(insn, inst2);
decode_insn = thumb32_probes_decode_insn;
actions = kprobes_t32_actions;
+ checkers = kprobes_t32_checkers;
} else {
decode_insn = thumb16_probes_decode_insn;
actions = kprobes_t16_actions;
+ checkers = kprobes_t16_checkers;
}
#else /* !CONFIG_THUMB2_KERNEL */
thumb = false;
@@ -85,12 +88,13 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
insn = __mem_to_opcode_arm(*p->addr);
decode_insn = arm_probes_decode_insn;
actions = kprobes_arm_actions;
+ checkers = kprobes_arm_checkers;
#endif
p->opcode = insn;
p->ainsn.insn = tmp_insn;
- switch ((*decode_insn)(insn, &p->ainsn, true, actions)) {
+ switch ((*decode_insn)(insn, &p->ainsn, true, actions, checkers)) {
case INSN_REJECTED: /* not supported */
return -EINVAL;
diff --git a/arch/arm/probes/kprobes/core.h b/arch/arm/probes/kprobes/core.h
index 2e1e5a3d9155..f88c79fe632a 100644
--- a/arch/arm/probes/kprobes/core.h
+++ b/arch/arm/probes/kprobes/core.h
@@ -37,16 +37,19 @@ kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_probes_insn *asi,
typedef enum probes_insn (kprobe_decode_insn_t)(probes_opcode_t,
struct arch_probes_insn *,
bool,
- const union decode_action *);
+ const union decode_action *,
+ const struct decode_checker *[*]);
#ifdef CONFIG_THUMB2_KERNEL
extern const union decode_action kprobes_t32_actions[];
extern const union decode_action kprobes_t16_actions[];
-
+extern const struct decode_checker *kprobes_t32_checkers[];
+extern const struct decode_checker *kprobes_t16_checkers[];
#else /* !CONFIG_THUMB2_KERNEL */
extern const union decode_action kprobes_arm_actions[];
+extern const struct decode_checker *kprobes_arm_checkers[];
#endif
diff --git a/arch/arm/probes/uprobes/core.c b/arch/arm/probes/uprobes/core.c
index b2954f6d3abe..d1329f1ba4e4 100644
--- a/arch/arm/probes/uprobes/core.c
+++ b/arch/arm/probes/uprobes/core.c
@@ -88,7 +88,7 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
auprobe->ixol[1] = __opcode_to_mem_arm(UPROBE_SS_ARM_INSN);
ret = arm_probes_decode_insn(insn, &auprobe->asi, false,
- uprobes_probes_actions);
+ uprobes_probes_actions, NULL);
switch (ret) {
case INSN_REJECTED:
return -EINVAL;