diff options
Diffstat (limited to 'kernel/test_kprobes.c')
| -rw-r--r-- | kernel/test_kprobes.c | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/kernel/test_kprobes.c b/kernel/test_kprobes.c new file mode 100644 index 000000000..76c997fdb --- /dev/null +++ b/kernel/test_kprobes.c @@ -0,0 +1,313 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * test_kprobes.c - simple sanity test for *probes + * + * Copyright IBM Corp. 2008 + */ + +#define pr_fmt(fmt) "Kprobe smoke test: " fmt + +#include <linux/kernel.h> +#include <linux/kprobes.h> +#include <linux/random.h> + +#define div_factor 3 + +static u32 rand1, preh_val, posth_val; +static int errors, handler_errors, num_tests; +static u32 (*target)(u32 value); +static u32 (*target2)(u32 value); + +static noinline u32 kprobe_target(u32 value) +{ + return (value / div_factor); +} + +static int kp_pre_handler(struct kprobe *p, struct pt_regs *regs) +{ + if (preemptible()) { + handler_errors++; + pr_err("pre-handler is preemptible\n"); + } + preh_val = (rand1 / div_factor); + return 0; +} + +static void kp_post_handler(struct kprobe *p, struct pt_regs *regs, + unsigned long flags) +{ + if (preemptible()) { + handler_errors++; + pr_err("post-handler is preemptible\n"); + } + if (preh_val != (rand1 / div_factor)) { + handler_errors++; + pr_err("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) { + pr_err("register_kprobe returned %d\n", ret); + return ret; + } + + ret = target(rand1); + unregister_kprobe(&kp); + + if (preh_val == 0) { + pr_err("kprobe pre_handler not called\n"); + handler_errors++; + } + + if (posth_val == 0) { + pr_err("kprobe post_handler not called\n"); + handler_errors++; + } + + return 0; +} + +static noinline u32 kprobe_target2(u32 value) +{ + return (value / div_factor) + 1; +} + +static int kp_pre_handler2(struct kprobe *p, struct pt_regs *regs) +{ + preh_val = (rand1 / div_factor) + 1; + return 0; +} + +static void kp_post_handler2(struct kprobe *p, struct pt_regs *regs, + unsigned long flags) +{ + if (preh_val != (rand1 / div_factor) + 1) { + handler_errors++; + pr_err("incorrect value in post_handler2\n"); + } + posth_val = preh_val + div_factor; +} + +static struct kprobe kp2 = { + .symbol_name = "kprobe_target2", + .pre_handler = kp_pre_handler2, + .post_handler = kp_post_handler2 +}; + +static int test_kprobes(void) +{ + int ret; + struct kprobe *kps[2] = {&kp, &kp2}; + + /* addr and flags should be cleard for reusing kprobe. */ + kp.addr = NULL; + kp.flags = 0; + ret = register_kprobes(kps, 2); + if (ret < 0) { + pr_err("register_kprobes returned %d\n", ret); + return ret; + } + + preh_val = 0; + posth_val = 0; + ret = target(rand1); + + if (preh_val == 0) { + pr_err("kprobe pre_handler not called\n"); + handler_errors++; + } + + if (posth_val == 0) { + pr_err("kprobe post_handler not called\n"); + handler_errors++; + } + + preh_val = 0; + posth_val = 0; + ret = target2(rand1); + + if (preh_val == 0) { + pr_err("kprobe pre_handler2 not called\n"); + handler_errors++; + } + + if (posth_val == 0) { + pr_err("kprobe post_handler2 not called\n"); + handler_errors++; + } + + unregister_kprobes(kps, 2); + return 0; + +} + +#ifdef CONFIG_KRETPROBES +static u32 krph_val; + +static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs) +{ + if (preemptible()) { + handler_errors++; + pr_err("kretprobe entry handler is preemptible\n"); + } + krph_val = (rand1 / div_factor); + return 0; +} + +static int return_handler(struct kretprobe_instance *ri, struct pt_regs *regs) +{ + unsigned long ret = regs_return_value(regs); + + if (preemptible()) { + handler_errors++; + pr_err("kretprobe return handler is preemptible\n"); + } + if (ret != (rand1 / div_factor)) { + handler_errors++; + pr_err("incorrect value in kretprobe handler\n"); + } + if (krph_val == 0) { + handler_errors++; + pr_err("call to kretprobe entry handler failed\n"); + } + + krph_val = rand1; + return 0; +} + +static struct kretprobe rp = { + .handler = return_handler, + .entry_handler = entry_handler, + .kp.symbol_name = "kprobe_target" +}; + +static int test_kretprobe(void) +{ + int ret; + + ret = register_kretprobe(&rp); + if (ret < 0) { + pr_err("register_kretprobe returned %d\n", ret); + return ret; + } + + ret = target(rand1); + unregister_kretprobe(&rp); + if (krph_val != rand1) { + pr_err("kretprobe handler not called\n"); + handler_errors++; + } + + return 0; +} + +static int return_handler2(struct kretprobe_instance *ri, struct pt_regs *regs) +{ + unsigned long ret = regs_return_value(regs); + + if (ret != (rand1 / div_factor) + 1) { + handler_errors++; + pr_err("incorrect value in kretprobe handler2\n"); + } + if (krph_val == 0) { + handler_errors++; + pr_err("call to kretprobe entry handler failed\n"); + } + + krph_val = rand1; + return 0; +} + +static struct kretprobe rp2 = { + .handler = return_handler2, + .entry_handler = entry_handler, + .kp.symbol_name = "kprobe_target2" +}; + +static int test_kretprobes(void) +{ + int ret; + struct kretprobe *rps[2] = {&rp, &rp2}; + + /* addr and flags should be cleard for reusing kprobe. */ + rp.kp.addr = NULL; + rp.kp.flags = 0; + ret = register_kretprobes(rps, 2); + if (ret < 0) { + pr_err("register_kretprobe returned %d\n", ret); + return ret; + } + + krph_val = 0; + ret = target(rand1); + if (krph_val != rand1) { + pr_err("kretprobe handler not called\n"); + handler_errors++; + } + + krph_val = 0; + ret = target2(rand1); + if (krph_val != rand1) { + pr_err("kretprobe handler2 not called\n"); + handler_errors++; + } + unregister_kretprobes(rps, 2); + return 0; +} +#endif /* CONFIG_KRETPROBES */ + +int init_test_probes(void) +{ + int ret; + + target = kprobe_target; + target2 = kprobe_target2; + + do { + rand1 = prandom_u32(); + } while (rand1 <= div_factor); + + pr_info("started\n"); + num_tests++; + ret = test_kprobe(); + if (ret < 0) + errors++; + + num_tests++; + ret = test_kprobes(); + if (ret < 0) + errors++; + +#ifdef CONFIG_KRETPROBES + num_tests++; + ret = test_kretprobe(); + if (ret < 0) + errors++; + + num_tests++; + ret = test_kretprobes(); + if (ret < 0) + errors++; +#endif /* CONFIG_KRETPROBES */ + + if (errors) + pr_err("BUG: %d out of %d tests failed\n", errors, num_tests); + else if (handler_errors) + pr_err("BUG: %d error(s) running handlers\n", handler_errors); + else + pr_info("passed successfully\n"); + + return 0; +} |