diff options
| -rw-r--r-- | include/linux/kprobes.h | 10 | ||||
| -rw-r--r-- | kernel/Makefile | 1 | ||||
| -rw-r--r-- | kernel/kprobes.c | 2 | ||||
| -rw-r--r-- | kernel/test_kprobes.c | 216 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 12 |
5 files changed, 241 insertions, 0 deletions
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 8189158..6168c0a 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -182,6 +182,15 @@ static inline void kretprobe_assert(struct kretprobe_instance *ri, } } +#ifdef CONFIG_KPROBES_SANITY_TEST +extern int init_test_probes(void); +#else +static inline int init_test_probes(void) +{ + return 0; +} +#endif /* CONFIG_KPROBES_SANITY_TEST */ + extern spinlock_t kretprobe_lock; extern struct mutex kprobe_mutex; extern int arch_prepare_kprobe(struct kprobe *p); @@ -227,6 +236,7 @@ void unregister_kretprobe(struct kretprobe *rp); void kprobe_flush_task(struct task_struct *tk); void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); + #else /* CONFIG_KPROBES */ #define __kprobes /**/ diff --git a/kernel/Makefile b/kernel/Makefile index 390d421..62015c3 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -43,6 +43,7 @@ obj-$(CONFIG_CPUSETS) += cpuset.o obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o obj-$(CONFIG_IKCONFIG) += configs.o obj-$(CONFIG_STOP_MACHINE) += stop_machine.o +obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o obj-$(CONFIG_AUDIT) += audit.o auditfilter.o obj-$(CONFIG_AUDITSYSCALL) += auditsc.o obj-$(CONFIG_AUDIT_TREE) += audit_tree.o diff --git a/kernel/kprobes.c b/kernel/kprobes.c index e3a5d81..d0493ea 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -824,6 +824,8 @@ static int __init init_kprobes(void) if (!err) err = register_die_notifier(&kprobe_exceptions_nb); + if (!err) + init_test_probes(); return err; } diff --git a/kernel/test_kprobes.c b/kernel/test_kprobes.c new file mode 100644 index 0000000..88cdb10 --- /dev/null +++ b/kernel/test_kprobes.c @@ -0,0 +1,216 @@ +/* + * test_kprobes.c - simple sanity test for *probes + * + * Copyright IBM Corp. 2008 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it would be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + */ + +#include <linux/kernel.h> +#include <linux/kprobes.h> +#include <linux/random.h> + +#define div_factor 3 + +static u32 rand1, preh_val, posth_val, jph_val; +static int errors, handler_errors, num_tests; + +static noinline u32 kprobe_target(u32 value) +{ + /* + * gcc ignores noinline on some architectures unless we stuff + * sufficient lard into the function. The get_kprobe() here is + * just for that. + * + * NOTE: We aren't concerned about the correctness of get_kprobe() + * here; hence, this call is neither under !preempt nor with the + * kprobe_mutex held. This is fine(tm) + */ + if (get_kprobe((void *)0xdeadbeef)) + printk(KERN_INFO "Kprobe smoke test: probe on 0xdeadbeef!\n"); + + return (value / div_factor); +} + +static int kp_pre_handler(struct kprobe *p, struct pt_regs *regs) +{ + preh_val = (rand1 / div_factor); + return 0; +} + +static void kp_post_handler(struct kprobe *p, struct pt_regs *regs, + unsigned long flags) +{ + if (preh_val != (rand1 / div_factor)) { + handler_errors++; + printk(KERN_ERR "Kprobe smoke test failed: " + "incorrect value in post_handler\n"); + } + posth_val = preh_val + div_factor; +} + +static struct kprobe kp = { + .symbol_name = "kprobe_target", + .pre_handler = kp_pre_handler, + .post_handler = kp_post_handler +}; + +static int test_kprobe(void) +{ + int ret; + + ret = register_kprobe(&kp); + if (ret < 0) { + printk(KERN_ERR "Kprobe smoke test failed: " + "register_kprobe returned %d\n", ret); + return ret; + } + + ret = kprobe_target(rand1); + unregister_kprobe(&kp); + + if (preh_val == 0) { + printk(KERN_ERR "Kprobe smoke test failed: " + "kprobe pre_handler not called\n"); + handler_errors++; + } + + if (posth_val == 0) { + printk(KERN_ERR "Kprobe smoke test failed: " + "kprobe post_handler not called\n"); + handler_errors++; + } + + return 0; +} + +static u32 j_kprobe_target(u32 value) +{ + if (value != rand1) { + handler_errors++; + printk(KERN_ERR "Kprobe smoke test failed: " + "incorrect value in jprobe handler\n"); + } + + jph_val = rand1; + jprobe_return(); + return 0; +} + +static struct jprobe jp = { + .entry = j_kprobe_target, + .kp.symbol_name = "kprobe_target" +}; + +static int test_jprobe(void) +{ + int ret; + + ret = register_jprobe(&jp); + if (ret < 0) { + printk(KERN_ERR "Kprobe smoke test failed: " + "register_jprobe returned %d\n", ret); + return ret; + } + + ret = kprobe_target(rand1); + unregister_jprobe(&jp); + if (jph_val == 0) { + printk(KERN_ERR "Kprobe smoke test failed: " + "jprobe handler not called\n"); + handler_errors++; + } + + return 0; +} + +#ifdef CONFIG_KRETPROBES +static u32 krph_val; + +static int return_handler(struct kretprobe_instance *ri, struct pt_regs *regs) +{ + unsigned long ret = regs_return_value(regs); + + if (ret != (rand1 / div_factor)) { + handler_errors++; + printk(KERN_ERR "Kprobe smoke test failed: " + "incorrect value in kretprobe handler\n"); + } + + krph_val = (rand1 / div_factor); + return 0; +} + +static struct kretprobe rp = { + .handler = return_handler, + .kp.symbol_name = "kprobe_target" +}; + +static int test_kretprobe(void) +{ + int ret; + + ret = register_kretprobe(&rp); + if (ret < 0) { + printk(KERN_ERR "Kprobe smoke test failed: " + "register_kretprobe returned %d\n", ret); + return ret; + } + + ret = kprobe_target(rand1); + unregister_kretprobe(&rp); + if (krph_val == 0) { + printk(KERN_ERR "Kprobe smoke test failed: " + "kretprobe handler not called\n"); + handler_errors++; + } + + return 0; +} +#endif /* CONFIG_KRETPROBES */ + +int init_test_probes(void) +{ + int ret; + + do { + rand1 = random32(); + } while (rand1 <= div_factor); + + printk(KERN_INFO "Kprobe smoke test started\n"); + num_tests++; + ret = test_kprobe(); + if (ret < 0) + errors++; + + num_tests++; + ret = test_jprobe(); + if (ret < 0) + errors++; + +#ifdef CONFIG_KRETPROBES + num_tests++; + ret = test_kretprobe(); + if (ret < 0) + errors++; +#endif /* CONFIG_KRETPROBES */ + + if (errors) + printk(KERN_ERR "BUG: Kprobe smoke test: %d out of " + "%d tests failed\n", errors, num_tests); + else if (handler_errors) + printk(KERN_ERR "BUG: Kprobe smoke test: %d error(s) " + "running handlers\n", handler_errors); + else + printk(KERN_INFO "Kprobe smoke test passed successfully\n"); + + return 0; +} diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c4ecb29..f535b9b 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -494,6 +494,18 @@ config RCU_TORTURE_TEST Say M if you want the RCU torture tests to build as a module. Say N if you are unsure. +config KPROBES_SANITY_TEST + bool "Kprobes sanity tests" + depends on DEBUG_KERNEL + depends on KPROBES + default n + help + This option provides for testing basic kprobes functionality on + boot. A sample kprobe, jprobe and kretprobe are inserted and + verified for functionality. + + Say N if you are unsure. + config LKDTM tristate "Linux Kernel Dump Test Tool Module" depends on DEBUG_KERNEL |