(2014/11/18 15:19), Wang Nan wrote: > This patch introdces 'checker' to decoding phase, and calls checkers > when instruction decoding. This allows further decoding for specific > instructions. > > v1 -> v2: > - kprobe checker stubs are introduced in this patch.
Hmm, could you state this patch just introduce a "stub" call of the checker in the patch description? (not only version comment) Other parts are OK to me. Reviewed-by: Masami Hiramatsu <[email protected]> Thank you, > > Signed-off-by: Wang Nan <[email protected]> > --- > arch/arm/kernel/kprobes-arm.c | 2 ++ > arch/arm/kernel/kprobes-thumb.c | 3 +++ > arch/arm/kernel/kprobes.c | 6 ++++- > arch/arm/kernel/kprobes.h | 7 ++++-- > arch/arm/kernel/probes-arm.c | 5 ++-- > arch/arm/kernel/probes-arm.h | 3 ++- > arch/arm/kernel/probes-thumb.c | 10 ++++---- > arch/arm/kernel/probes-thumb.h | 6 +++-- > arch/arm/kernel/probes.c | 51 > ++++++++++++++++++++++++++++++++++++++++- > arch/arm/kernel/probes.h | 11 ++++++++- > arch/arm/kernel/uprobes.c | 2 +- > 11 files changed, 91 insertions(+), 15 deletions(-) > > diff --git a/arch/arm/kernel/kprobes-arm.c b/arch/arm/kernel/kprobes-arm.c > index ac300c6..5a81275 100644 > --- a/arch/arm/kernel/kprobes-arm.c > +++ b/arch/arm/kernel/kprobes-arm.c > @@ -341,3 +341,5 @@ 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/kernel/kprobes-thumb.c b/arch/arm/kernel/kprobes-thumb.c > index 9495d7f..b8ba7d2 100644 > --- a/arch/arm/kernel/kprobes-thumb.c > +++ b/arch/arm/kernel/kprobes-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/kernel/kprobes.c b/arch/arm/kernel/kprobes.c > index 6d64420..f114a3f 100644 > --- a/arch/arm/kernel/kprobes.c > +++ b/arch/arm/kernel/kprobes.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, NULL)) { > case INSN_REJECTED: /* not supported */ > return -EINVAL; > > diff --git a/arch/arm/kernel/kprobes.h b/arch/arm/kernel/kprobes.h > index 9a2712e..05f3b40 100644 > --- a/arch/arm/kernel/kprobes.h > +++ b/arch/arm/kernel/kprobes.h > @@ -36,16 +36,19 @@ 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/kernel/probes-arm.c b/arch/arm/kernel/probes-arm.c > index 8eaef81..125feda 100644 > --- a/arch/arm/kernel/probes-arm.c > +++ b/arch/arm/kernel/probes-arm.c > @@ -725,10 +725,11 @@ 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/kernel/probes-arm.h b/arch/arm/kernel/probes-arm.h > index ace6572..8b11ec4 100644 > --- a/arch/arm/kernel/probes-arm.h > +++ b/arch/arm/kernel/probes-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/kernel/probes-thumb.c b/arch/arm/kernel/probes-thumb.c > index 4131351..a5022b4 100644 > --- a/arch/arm/kernel/probes-thumb.c > +++ b/arch/arm/kernel/probes-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/kernel/probes-thumb.h b/arch/arm/kernel/probes-thumb.h > index 7c6f6eb..ccfe3e4 100644 > --- a/arch/arm/kernel/probes-thumb.h > +++ b/arch/arm/kernel/probes-thumb.h > @@ -89,9 +89,11 @@ 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/kernel/probes.c b/arch/arm/kernel/probes.c > index a8ab540..02598da 100644 > --- a/arch/arm/kernel/probes.c > +++ b/arch/arm/kernel/probes.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); > @@ -422,18 +453,36 @@ 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; > + int action = d->decoder.action; > + > + err = run_checkers(checkers, action, origin_insn, asi, > h); > + if (err == INSN_REJECTED) > + return INSN_REJECTED; > return actions[d->decoder.action].decoder(insn, asi, h); > } > > case DECODE_TYPE_SIMULATE: { > + int err; > struct decode_simulate *d = (struct decode_simulate *)h; > + 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[d->handler.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, > diff --git a/arch/arm/kernel/probes.h b/arch/arm/kernel/probes.h > index dba9f24..b4bf1f5 100644 > --- a/arch/arm/kernel/probes.h > +++ b/arch/arm/kernel/probes.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/kernel/uprobes.c b/arch/arm/kernel/uprobes.c > index 56adf9c..372585a 100644 > --- a/arch/arm/kernel/uprobes.c > +++ b/arch/arm/kernel/uprobes.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; > -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: [email protected] -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
