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![Abhishek Sagar](/assets/img/avatar_default.png)
Provide support to add an optional user defined callback to be run at function entry of a kretprobe'd function. Also modify the kprobe smoke tests to include an entry-handler during the kretprobe sanity test. Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Acked-by: Jim Keniston <jkenisto@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
228 lines
4.9 KiB
C
228 lines
4.9 KiB
C
/*
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* test_kprobes.c - simple sanity test for *probes
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*
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* Copyright IBM Corp. 2008
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it would be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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* the GNU General Public License for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/kprobes.h>
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#include <linux/random.h>
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#define div_factor 3
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static u32 rand1, preh_val, posth_val, jph_val;
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static int errors, handler_errors, num_tests;
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static noinline u32 kprobe_target(u32 value)
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{
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/*
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* gcc ignores noinline on some architectures unless we stuff
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* sufficient lard into the function. The get_kprobe() here is
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* just for that.
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*
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* NOTE: We aren't concerned about the correctness of get_kprobe()
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* here; hence, this call is neither under !preempt nor with the
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* kprobe_mutex held. This is fine(tm)
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*/
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if (get_kprobe((void *)0xdeadbeef))
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printk(KERN_INFO "Kprobe smoke test: probe on 0xdeadbeef!\n");
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return (value / div_factor);
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}
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static int kp_pre_handler(struct kprobe *p, struct pt_regs *regs)
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{
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preh_val = (rand1 / div_factor);
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return 0;
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}
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static void kp_post_handler(struct kprobe *p, struct pt_regs *regs,
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unsigned long flags)
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{
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if (preh_val != (rand1 / div_factor)) {
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handler_errors++;
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printk(KERN_ERR "Kprobe smoke test failed: "
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"incorrect value in post_handler\n");
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}
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posth_val = preh_val + div_factor;
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}
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static struct kprobe kp = {
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.symbol_name = "kprobe_target",
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.pre_handler = kp_pre_handler,
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.post_handler = kp_post_handler
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};
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static int test_kprobe(void)
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{
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int ret;
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ret = register_kprobe(&kp);
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if (ret < 0) {
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printk(KERN_ERR "Kprobe smoke test failed: "
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"register_kprobe returned %d\n", ret);
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return ret;
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}
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ret = kprobe_target(rand1);
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unregister_kprobe(&kp);
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if (preh_val == 0) {
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printk(KERN_ERR "Kprobe smoke test failed: "
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"kprobe pre_handler not called\n");
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handler_errors++;
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}
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if (posth_val == 0) {
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printk(KERN_ERR "Kprobe smoke test failed: "
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"kprobe post_handler not called\n");
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handler_errors++;
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}
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return 0;
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}
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static u32 j_kprobe_target(u32 value)
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{
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if (value != rand1) {
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handler_errors++;
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printk(KERN_ERR "Kprobe smoke test failed: "
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"incorrect value in jprobe handler\n");
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}
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jph_val = rand1;
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jprobe_return();
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return 0;
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}
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static struct jprobe jp = {
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.entry = j_kprobe_target,
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.kp.symbol_name = "kprobe_target"
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};
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static int test_jprobe(void)
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{
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int ret;
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ret = register_jprobe(&jp);
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if (ret < 0) {
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printk(KERN_ERR "Kprobe smoke test failed: "
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"register_jprobe returned %d\n", ret);
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return ret;
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}
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ret = kprobe_target(rand1);
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unregister_jprobe(&jp);
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if (jph_val == 0) {
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printk(KERN_ERR "Kprobe smoke test failed: "
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"jprobe handler not called\n");
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handler_errors++;
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}
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return 0;
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}
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#ifdef CONFIG_KRETPROBES
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static u32 krph_val;
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static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
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{
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krph_val = (rand1 / div_factor);
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return 0;
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}
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static int return_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
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{
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unsigned long ret = regs_return_value(regs);
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if (ret != (rand1 / div_factor)) {
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handler_errors++;
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printk(KERN_ERR "Kprobe smoke test failed: "
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"incorrect value in kretprobe handler\n");
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}
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if (krph_val == 0) {
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handler_errors++;
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printk(KERN_ERR "Kprobe smoke test failed: "
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"call to kretprobe entry handler failed\n");
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}
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krph_val = rand1;
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return 0;
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}
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static struct kretprobe rp = {
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.handler = return_handler,
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.entry_handler = entry_handler,
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.kp.symbol_name = "kprobe_target"
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};
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static int test_kretprobe(void)
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{
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int ret;
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ret = register_kretprobe(&rp);
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if (ret < 0) {
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printk(KERN_ERR "Kprobe smoke test failed: "
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"register_kretprobe returned %d\n", ret);
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return ret;
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}
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ret = kprobe_target(rand1);
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unregister_kretprobe(&rp);
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if (krph_val != rand1) {
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printk(KERN_ERR "Kprobe smoke test failed: "
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"kretprobe handler not called\n");
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handler_errors++;
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}
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return 0;
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}
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#endif /* CONFIG_KRETPROBES */
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int init_test_probes(void)
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{
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int ret;
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do {
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rand1 = random32();
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} while (rand1 <= div_factor);
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printk(KERN_INFO "Kprobe smoke test started\n");
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num_tests++;
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ret = test_kprobe();
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if (ret < 0)
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errors++;
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num_tests++;
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ret = test_jprobe();
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if (ret < 0)
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errors++;
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#ifdef CONFIG_KRETPROBES
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num_tests++;
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ret = test_kretprobe();
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if (ret < 0)
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errors++;
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#endif /* CONFIG_KRETPROBES */
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if (errors)
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printk(KERN_ERR "BUG: Kprobe smoke test: %d out of "
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"%d tests failed\n", errors, num_tests);
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else if (handler_errors)
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printk(KERN_ERR "BUG: Kprobe smoke test: %d error(s) "
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"running handlers\n", handler_errors);
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else
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printk(KERN_INFO "Kprobe smoke test passed successfully\n");
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return 0;
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}
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