[v3,1/3] ARM: kprobes: introduces checker

Message ID	1416551731-50777-2-git-send-email-wangnan0@huawei.com
State	New
Headers	show Return-Path: <patchwork-forward+bncBD2YXXXCQEBBBPF4XORQKGQELOLCXSI@linaro.org> Received-SPF: pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.217.182 as permitted sender) client-ip=209.85.217.182; Received-SPF: none (google.com: linux-kernel-owner@vger.kernel.org does not designate permitted sender hosts) client-ip=209.132.180.67; From: Wang Nan <wangnan0@huawei.com> To: <tixy@linaro.org>, <masami.hiramatsu.pt@hitachi.com>, <linux@arm.linux.org.uk>, <will.deacon@arm.com>, <taras.kondratiuk@linaro.org>, <ben.dooks@codethink.co.uk>, <cl@linux.com>, <rabin@rab.in>, <davem@davemloft.net> CC: <lizefan@huawei.com>, <linux-kernel@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org> Subject: [PATCH v3 1/3] ARM: kprobes: introduces checker Date: Fri, 21 Nov 2014 14:35:29 +0800 Message-ID: <1416551731-50777-2-git-send-email-wangnan0@huawei.com> In-Reply-To: <1416551731-50777-1-git-send-email-wangnan0@huawei.com> References: <1416551731-50777-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: list Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org

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..d7bee4b 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, checkers)) { 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..6a7d92e 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); @@ -422,24 +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/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;

[v3,1/3] ARM: kprobes: introduces checker

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