// SPDX-License-Identifier: GPL-2.0 /* Include in trace.c */ #include <uapi/linux/sched/types.h> #include <linux/stringify.h> #include <linux/kthread.h> #include <linux/delay.h> #include <linux/slab.h> static inline int trace_valid_entry(struct trace_entry *entry) { switch (entry->type) { case TRACE_FN: case TRACE_CTX: case TRACE_WAKE: case TRACE_STACK: case TRACE_PRINT: case TRACE_BRANCH: case TRACE_GRAPH_ENT: case TRACE_GRAPH_RET: return 1; } return 0; } static int trace_test_buffer_cpu(struct array_buffer *buf, int cpu) { struct ring_buffer_event *event; struct trace_entry *entry; unsigned int loops = 0; while ((event = ring_buffer_consume(buf->buffer, cpu, NULL, NULL))) { entry = ring_buffer_event_data(event); /* * The ring buffer is a size of trace_buf_size, if * we loop more than the size, there's something wrong * with the ring buffer. */ if (loops++ > trace_buf_size) { printk(KERN_CONT ".. bad ring buffer "); goto failed; } if (!trace_valid_entry(entry)) { printk(KERN_CONT ".. invalid entry %d ", entry->type); goto failed; } } return 0; failed: /* disable tracing */ tracing_disabled = 1; printk(KERN_CONT ".. corrupted trace buffer .. "); return -1; } /* * Test the trace buffer to see if all the elements * are still sane. */ static int __maybe_unused trace_test_buffer(struct array_buffer *buf, unsigned long *count) { unsigned long flags, cnt = 0; int cpu, ret = 0; /* Don't allow flipping of max traces now */ local_irq_save(flags); arch_spin_lock(&buf->tr->max_lock); cnt = ring_buffer_entries(buf->buffer); /* * The trace_test_buffer_cpu runs a while loop to consume all data. * If the calling tracer is broken, and is constantly filling * the buffer, this will run forever, and hard lock the box. * We disable the ring buffer while we do this test to prevent * a hard lock up. */ tracing_off(); for_each_possible_cpu(cpu) { ret = trace_test_buffer_cpu(buf, cpu); if (ret) break; } tracing_on(); arch_spin_unlock(&buf->tr->max_lock); local_irq_restore(flags); if (count) *count = cnt; return ret; } static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret) { printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n", trace->name, init_ret); } #ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE static int trace_selftest_test_probe1_cnt; static void trace_selftest_test_probe1_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, struct ftrace_regs *fregs) { trace_selftest_test_probe1_cnt++; } static int trace_selftest_test_probe2_cnt; static void trace_selftest_test_probe2_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, struct ftrace_regs *fregs) { trace_selftest_test_probe2_cnt++; } static int trace_selftest_test_probe3_cnt; static void trace_selftest_test_probe3_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, struct ftrace_regs *fregs) { trace_selftest_test_probe3_cnt++; } static int trace_selftest_test_global_cnt; static void trace_selftest_test_global_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, struct ftrace_regs *fregs) { trace_selftest_test_global_cnt++; } static int trace_selftest_test_dyn_cnt; static void trace_selftest_test_dyn_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, struct ftrace_regs *fregs) { trace_selftest_test_dyn_cnt++; } static struct ftrace_ops test_probe1 = { .func = trace_selftest_test_probe1_func, }; static struct ftrace_ops test_probe2 = { .func = trace_selftest_test_probe2_func, }; static struct ftrace_ops test_probe3 = { .func = trace_selftest_test_probe3_func, }; static void print_counts(void) { printk("(%d %d %d %d %d) ", trace_selftest_test_probe1_cnt, trace_selftest_test_probe2_cnt, trace_selftest_test_probe3_cnt, trace_selftest_test_global_cnt, trace_selftest_test_dyn_cnt); } static void reset_counts(void) { trace_selftest_test_probe1_cnt = 0; trace_selftest_test_probe2_cnt = 0; trace_selftest_test_probe3_cnt = 0; trace_selftest_test_global_cnt = 0; trace_selftest_test_dyn_cnt = 0; } static int trace_selftest_ops(struct trace_array *tr, int cnt) { int save_ftrace_enabled = ftrace_enabled; struct ftrace_ops *dyn_ops; char *func1_name; char *func2_name; int len1; int len2; int ret = -1; printk(KERN_CONT "PASSED\n"); pr_info("Testing dynamic ftrace ops #%d: ", cnt); ftrace_enabled = 1; reset_counts(); /* Handle PPC64 '.' name */ func1_name = "*" __stringify(DYN_FTRACE_TEST_NAME); func2_name = "*" __stringify(DYN_FTRACE_TEST_NAME2); len1 = strlen(func1_name); len2 = strlen(func2_name); /* * Probe 1 will trace function 1. * Probe 2 will trace function 2. * Probe 3 will trace functions 1 and 2. */ ftrace_set_filter(&test_probe1, func1_name, len1, 1); ftrace_set_filter(&test_probe2, func2_name, len2, 1); ftrace_set_filter(&test_probe3, func1_name, len1, 1); ftrace_set_filter(&test_probe3, func2_name, len2, 0); register_ftrace_function(&test_probe1); register_ftrace_function(&test_probe2); register_ftrace_function(&test_probe3); /* First time we are running with main function */ if (cnt > 1) { ftrace_init_array_ops(tr, trace_selftest_test_global_func); register_ftrace_function(tr->ops); } DYN_FTRACE_TEST_NAME(); print_counts(); if (trace_selftest_test_probe1_cnt != 1) goto out; if (trace_selftest_test_probe2_cnt != 0) goto out; if (trace_selftest_test_probe3_cnt != 1) goto out; if (cnt > 1) { if (trace_selftest_test_global_cnt == 0) goto out; } DYN_FTRACE_TEST_NAME2(); print_counts(); if (trace_selftest_test_probe1_cnt != 1) goto out; if (trace_selftest_test_probe2_cnt != 1) goto out; if (trace_selftest_test_probe3_cnt != 2) goto out; /* Add a dynamic probe */ dyn_ops = kzalloc(sizeof(*dyn_ops), GFP_KERNEL); if (!dyn_ops) { printk("MEMORY ERROR "); goto out; } dyn_ops->func = trace_selftest_test_dyn_func; register_ftrace_function(dyn_ops); trace_selftest_test_global_cnt = 0; DYN_FTRACE_TEST_NAME(); print_counts(); if (trace_selftest_test_probe1_cnt != 2) goto out_free; if (trace_selftest_test_probe2_cnt != 1) goto out_free; if (trace_selftest_test_probe3_cnt != 3) goto out_free; if (cnt > 1) { if (trace_selftest_test_global_cnt == 0) goto out_free; } if (trace_selftest_test_dyn_cnt == 0) goto out_free; DYN_FTRACE_TEST_NAME2(); print_counts(); if (trace_selftest_test_probe1_cnt != 2) goto out_free; if (trace_selftest_test_probe2_cnt != 2) goto out_free; if (trace_selftest_test_probe3_cnt != 4) goto out_free; /* Remove trace function from probe 3 */ func1_name = "!" __stringify(DYN_FTRACE_TEST_NAME); len1 = strlen(func1_name); ftrace_set_filter(&test_probe3, func1_name, len1, 0); DYN_FTRACE_TEST_NAME(); print_counts(); if (trace_selftest_test_probe1_cnt != 3) goto out_free; if (trace_selftest_test_probe2_cnt != 2) goto out_free; if (trace_selftest_test_probe3_cnt != 4) goto out_free; if (cnt > 1) { if (trace_selftest_test_global_cnt == 0) goto out_free; } if (trace_selftest_test_dyn_cnt == 0) goto out_free; DYN_FTRACE_TEST_NAME2(); print_counts(); if (trace_selftest_test_probe1_cnt != 3) goto out_free; if (trace_selftest_test_probe2_cnt != 3) goto out_free; if (trace_selftest_test_probe3_cnt != 5) goto out_free; ret = 0; out_free: unregister_ftrace_function(dyn_ops); kfree(dyn_ops); out: /* Purposely unregister in the same order */ unregister_ftrace_function(&test_probe1); unregister_ftrace_function(&test_probe2); unregister_ftrace_function(&test_probe3); if (cnt > 1) unregister_ftrace_function(tr->ops); ftrace_reset_array_ops(tr); /* Make sure everything is off */ reset_counts(); DYN_FTRACE_TEST_NAME(); DYN_FTRACE_TEST_NAME(); if (trace_selftest_test_probe1_cnt || trace_selftest_test_probe2_cnt || trace_selftest_test_probe3_cnt || trace_selftest_test_global_cnt || trace_selftest_test_dyn_cnt) ret = -1; ftrace_enabled = save_ftrace_enabled; return ret; } /* Test dynamic code modification and ftrace filters */ static int trace_selftest_startup_dynamic_tracing(struct tracer *trace, struct trace_array *tr, int (*func)(void)) { int save_ftrace_enabled = ftrace_enabled; unsigned long count; char *func_name; int ret; /* The ftrace test PASSED */ printk(KERN_CONT "PASSED\n"); pr_info("Testing dynamic ftrace: "); /* enable tracing, and record the filter function */ ftrace_enabled = 1; /* passed in by parameter to fool gcc from optimizing */ func(); /* * Some archs *cough*PowerPC*cough* add characters to the * start of the function names. We simply put a '*' to * accommodate them. */ func_name = "*" __stringify(DYN_FTRACE_TEST_NAME); /* filter only on our function */ ftrace_set_global_filter(func_name, strlen(func_name), 1); /* enable tracing */ ret = tracer_init(trace, tr); if (ret) { warn_failed_init_tracer(trace, ret); goto out; } /* Sleep for a 1/10 of a second */ msleep(100); /* we should have nothing in the buffer */ ret = trace_test_buffer(&tr->array_buffer, &count); if (ret) goto out; if (count) { ret = -1; printk(KERN_CONT ".. filter did not filter .. "); goto out; } /* call our function again */ func(); /* sleep again */ msleep(100); /* stop the tracing. */ tracing_stop(); ftrace_enabled = 0; /* check the trace buffer */ ret = trace_test_buffer(&tr->array_buffer, &count); ftrace_enabled = 1; tracing_start(); /* we should only have one item */ if (!ret && count != 1) { trace->reset(tr); printk(KERN_CONT ".. filter failed count=%ld ..", count); ret = -1; goto out; } /* Test the ops with global tracing running */ ret = trace_selftest_ops(tr, 1); trace->reset(tr); out: ftrace_enabled = save_ftrace_enabled; /* Enable tracing on all functions again */ ftrace_set_global_filter(NULL, 0, 1); /* Test the ops with global tracing off */ if (!ret) ret = trace_selftest_ops(tr, 2); return ret; } static int trace_selftest_recursion_cnt; static void trace_selftest_test_recursion_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, struct ftrace_regs *fregs) { /* * This function is registered without the recursion safe flag. * The ftrace infrastructure should provide the recursion * protection. If not, this will crash the kernel! */ if (trace_selftest_recursion_cnt++ > 10) return; DYN_FTRACE_TEST_NAME(); } static void trace_selftest_test_recursion_safe_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, struct ftrace_regs *fregs) { /* * We said we would provide our own recursion. By calling * this function again, we should recurse back into this function * and count again. But this only happens if the arch supports * all of ftrace features and nothing else is using the function * tracing utility. */ if (trace_selftest_recursion_cnt++) return; DYN_FTRACE_TEST_NAME(); } static struct ftrace_ops test_rec_probe = { .func = trace_selftest_test_recursion_func, .flags = FTRACE_OPS_FL_RECURSION, }; static struct ftrace_ops test_recsafe_probe = { .func = trace_selftest_test_recursion_safe_func, }; static int trace_selftest_function_recursion(void) { int save_ftrace_enabled = ftrace_enabled; char *func_name; int len; int ret; /* The previous test PASSED */ pr_cont("PASSED\n"); pr_info("Testing ftrace recursion: "); /* enable tracing, and record the filter function */ ftrace_enabled = 1; /* Handle PPC64 '.' name */ func_name = "*" __stringify(DYN_FTRACE_TEST_NAME); len = strlen(func_name); ret = ftrace_set_filter(&test_rec_probe, func_name, len, 1); if (ret) { pr_cont("*Could not set filter* "); goto out; } ret = register_ftrace_function(&test_rec_probe); if (ret) { pr_cont("*could not register callback* "); goto out; } DYN_FTRACE_TEST_NAME(); unregister_ftrace_function(&test_rec_probe); ret = -1; /* * Recursion allows for transitions between context, * and may call the callback twice. */ if (trace_selftest_recursion_cnt != 1 && trace_selftest_recursion_cnt != 2) { pr_cont("*callback not called once (or twice) (%d)* ", trace_selftest_recursion_cnt); goto out; } trace_selftest_recursion_cnt = 1; pr_cont("PASSED\n"); pr_info("Testing ftrace recursion safe: "); ret = ftrace_set_filter(&test_recsafe_probe, func_name, len, 1); if (ret) { pr_cont("*Could not set filter* "); goto out; } ret = register_ftrace_function(&test_recsafe_probe); if (ret) { pr_cont("*could not register callback* "); goto out; } DYN_FTRACE_TEST_NAME(); unregister_ftrace_function(&test_recsafe_probe); ret = -1; if (trace_selftest_recursion_cnt != 2) { pr_cont("*callback not called expected 2 times (%d)* ", trace_selftest_recursion_cnt); goto out; } ret = 0; out: ftrace_enabled = save_ftrace_enabled; return ret; } #else # define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; }) # define trace_selftest_function_recursion() ({ 0; }) #endif /* CONFIG_DYNAMIC_FTRACE */ static enum { TRACE_SELFTEST_REGS_START, TRACE_SELFTEST_REGS_FOUND, TRACE_SELFTEST_REGS_NOT_FOUND, } trace_selftest_regs_stat; static void trace_selftest_test_regs_func(unsigned long ip, unsigned long pip, struct ftrace_ops *op, struct ftrace_regs *fregs) { struct pt_regs *regs = ftrace_get_regs(fregs); if (regs) trace_selftest_regs_stat = TRACE_SELFTEST_REGS_FOUND; else trace_selftest_regs_stat = TRACE_SELFTEST_REGS_NOT_FOUND; } static struct ftrace_ops test_regs_probe = { .func = trace_selftest_test_regs_func, .flags = FTRACE_OPS_FL_SAVE_REGS, }; static int trace_selftest_function_regs(void) { int save_ftrace_enabled = ftrace_enabled; char *func_name; int len; int ret; int supported = 0; #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS supported = 1; #endif /* The previous test PASSED */ pr_cont("PASSED\n"); pr_info("Testing ftrace regs%s: ", !supported ? "(no arch support)" : ""); /* enable tracing, and record the filter function */ ftrace_enabled = 1; /* Handle PPC64 '.' name */ func_name = "*" __stringify(DYN_FTRACE_TEST_NAME); len = strlen(func_name); ret = ftrace_set_filter(&test_regs_probe, func_name, len, 1); /* * If DYNAMIC_FTRACE is not set, then we just trace all functions. * This test really doesn't care. */ if (ret && ret != -ENODEV) { pr_cont("*Could not set filter* "); goto out; } ret = register_ftrace_function(&test_regs_probe); /* * Now if the arch does not support passing regs, then this should * have failed. */ if (!supported) { if (!ret) { pr_cont("*registered save-regs without arch support* "); goto out; } test_regs_probe.flags |= FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED; ret = register_ftrace_function(&test_regs_probe); } if (ret) { pr_cont("*could not register callback* "); goto out; } DYN_FTRACE_TEST_NAME(); unregister_ftrace_function(&test_regs_probe); ret = -1; switch (trace_selftest_regs_stat) { case TRACE_SELFTEST_REGS_START: pr_cont("*callback never called* "); goto out; case TRACE_SELFTEST_REGS_FOUND: if (supported) break; pr_cont("*callback received regs without arch support* "); goto out; case TRACE_SELFTEST_REGS_NOT_FOUND: if (!supported) break; pr_cont("*callback received NULL regs* "); goto out; } ret = 0; out: ftrace_enabled = save_ftrace_enabled; return ret; } /* * Simple verification test of ftrace function tracer. * Enable ftrace, sleep 1/10 second, and then read the trace * buffer to see if all is in order. */ __init int trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) { int save_ftrace_enabled = ftrace_enabled; unsigned long count; int ret; #ifdef CONFIG_DYNAMIC_FTRACE if (ftrace_filter_param) { printk(KERN_CONT " ... kernel command line filter set: force PASS ... "); return 0; } #endif /* make sure msleep has been recorded */ msleep(1); /* start the tracing */ ftrace_enabled = 1; ret = tracer_init(trace, tr); if (ret) { warn_failed_init_tracer(trace, ret); goto out; } /* Sleep for a 1/10 of a second */ msleep(100); /* stop the tracing. */ tracing_stop(); ftrace_enabled = 0; /* check the trace buffer */ ret = trace_test_buffer(&tr->array_buffer, &count); ftrace_enabled = 1; trace->reset(tr); tracing_start(); if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; goto out; } ret = trace_selftest_startup_dynamic_tracing(trace, tr, DYN_FTRACE_TEST_NAME); if (ret) goto out; ret = trace_selftest_function_recursion(); if (ret) goto out; ret = trace_selftest_function_regs(); out: ftrace_enabled = save_ftrace_enabled; /* kill ftrace totally if we failed */ if (ret) ftrace_kill(); return ret; } #endif /* CONFIG_FUNCTION_TRACER */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER /* Maximum number of functions to trace before diagnosing a hang */ #define GRAPH_MAX_FUNC_TEST 100000000 static unsigned int graph_hang_thresh; /* Wrap the real function entry probe to avoid possible hanging */ static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace) { /* This is harmlessly racy, we want to approximately detect a hang */ if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) { ftrace_graph_stop(); printk(KERN_WARNING "BUG: Function graph tracer hang!\n"); if (ftrace_dump_on_oops) { ftrace_dump(DUMP_ALL); /* ftrace_dump() disables tracing */ tracing_on(); } return 0; } return trace_graph_entry(trace); } static struct fgraph_ops fgraph_ops __initdata = { .entryfunc = &trace_graph_entry_watchdog, .retfunc = &trace_graph_return, }; #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS noinline __noclone static void trace_direct_tramp(void) { } #endif /* * Pretty much the same than for the function tracer from which the selftest * has been borrowed. */ __init int trace_selftest_startup_function_graph(struct tracer *trace, struct trace_array *tr) { int ret; unsigned long count; char *func_name __maybe_unused; #ifdef CONFIG_DYNAMIC_FTRACE if (ftrace_filter_param) { printk(KERN_CONT " ... kernel command line filter set: force PASS ... "); return 0; } #endif /* * Simulate the init() callback but we attach a watchdog callback * to detect and recover from possible hangs */ tracing_reset_online_cpus(&tr->array_buffer); set_graph_array(tr); ret = register_ftrace_graph(&fgraph_ops); if (ret) { warn_failed_init_tracer(trace, ret); goto out; } tracing_start_cmdline_record(); /* Sleep for a 1/10 of a second */ msleep(100); /* Have we just recovered from a hang? */ if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) { disable_tracing_selftest("recovering from a hang"); ret = -1; goto out; } tracing_stop(); /* check the trace buffer */ ret = trace_test_buffer(&tr->array_buffer, &count); /* Need to also simulate the tr->reset to remove this fgraph_ops */ tracing_stop_cmdline_record(); unregister_ftrace_graph(&fgraph_ops); tracing_start(); if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; goto out; } #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS tracing_reset_online_cpus(&tr->array_buffer); set_graph_array(tr); /* * Some archs *cough*PowerPC*cough* add characters to the * start of the function names. We simply put a '*' to * accommodate them. */ func_name = "*" __stringify(DYN_FTRACE_TEST_NAME); ftrace_set_global_filter(func_name, strlen(func_name), 1); /* * Register direct function together with graph tracer * and make sure we get graph trace. */ ret = register_ftrace_direct((unsigned long) DYN_FTRACE_TEST_NAME, (unsigned long) trace_direct_tramp); if (ret) goto out; ret = register_ftrace_graph(&fgraph_ops); if (ret) { warn_failed_init_tracer(trace, ret); goto out; } DYN_FTRACE_TEST_NAME(); count = 0; tracing_stop(); /* check the trace buffer */ ret = trace_test_buffer(&tr->array_buffer, &count); unregister_ftrace_graph(&fgraph_ops); ret = unregister_ftrace_direct((unsigned long) DYN_FTRACE_TEST_NAME, (unsigned long) trace_direct_tramp); if (ret) goto out; tracing_start(); if (!ret && !count) { ret = -1; goto out; } /* Enable tracing on all functions again */ ftrace_set_global_filter(NULL, 0, 1); #endif /* Don't test dynamic tracing, the function tracer already did */ out: /* Stop it if we failed */ if (ret) ftrace_graph_stop(); return ret; } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ #ifdef CONFIG_IRQSOFF_TRACER int trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr) { unsigned long save_max = tr->max_latency; unsigned long count; int ret; /* start the tracing */ ret = tracer_init(trace, tr); if (ret) { warn_failed_init_tracer(trace, ret); return ret; } /* reset the max latency */ tr->max_latency = 0; /* disable interrupts for a bit */ local_irq_disable(); udelay(100); local_irq_enable(); /* * Stop the tracer to avoid a warning subsequent * to buffer flipping failure because tracing_stop() * disables the tr and max buffers, making flipping impossible * in case of parallels max irqs off latencies. */ trace->stop(tr); /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(&tr->array_buffer, NULL); if (!ret) ret = trace_test_buffer(&tr->max_buffer, &count); trace->reset(tr); tracing_start(); if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; } tr->max_latency = save_max; return ret; } #endif /* CONFIG_IRQSOFF_TRACER */ #ifdef CONFIG_PREEMPT_TRACER int trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr) { unsigned long save_max = tr->max_latency; unsigned long count; int ret; /* * Now that the big kernel lock is no longer preemptible, * and this is called with the BKL held, it will always * fail. If preemption is already disabled, simply * pass the test. When the BKL is removed, or becomes * preemptible again, we will once again test this, * so keep it in. */ if (preempt_count()) { printk(KERN_CONT "can not test ... force "); return 0; } /* start the tracing */ ret = tracer_init(trace, tr); if (ret) { warn_failed_init_tracer(trace, ret); return ret; } /* reset the max latency */ tr->max_latency = 0; /* disable preemption for a bit */ preempt_disable(); udelay(100); preempt_enable(); /* * Stop the tracer to avoid a warning subsequent * to buffer flipping failure because tracing_stop() * disables the tr and max buffers, making flipping impossible * in case of parallels max preempt off latencies. */ trace->stop(tr); /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(&tr->array_buffer, NULL); if (!ret) ret = trace_test_buffer(&tr->max_buffer, &count); trace->reset(tr); tracing_start(); if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; } tr->max_latency = save_max; return ret; } #endif /* CONFIG_PREEMPT_TRACER */ #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER) int trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr) { unsigned long save_max = tr->max_latency; unsigned long count; int ret; /* * Now that the big kernel lock is no longer preemptible, * and this is called with the BKL held, it will always * fail. If preemption is already disabled, simply * pass the test. When the BKL is removed, or becomes * preemptible again, we will once again test this, * so keep it in. */ if (preempt_count()) { printk(KERN_CONT "can not test ... force "); return 0; } /* start the tracing */ ret = tracer_init(trace, tr); if (ret) { warn_failed_init_tracer(trace, ret); goto out_no_start; } /* reset the max latency */ tr->max_latency = 0; /* disable preemption and interrupts for a bit */ preempt_disable(); local_irq_disable(); udelay(100); preempt_enable(); /* reverse the order of preempt vs irqs */ local_irq_enable(); /* * Stop the tracer to avoid a warning subsequent * to buffer flipping failure because tracing_stop() * disables the tr and max buffers, making flipping impossible * in case of parallels max irqs/preempt off latencies. */ trace->stop(tr); /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(&tr->array_buffer, NULL); if (ret) goto out; ret = trace_test_buffer(&tr->max_buffer, &count); if (ret) goto out; if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; goto out; } /* do the test by disabling interrupts first this time */ tr->max_latency = 0; tracing_start(); trace->start(tr); preempt_disable(); local_irq_disable(); udelay(100); preempt_enable(); /* reverse the order of preempt vs irqs */ local_irq_enable(); trace->stop(tr); /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(&tr->array_buffer, NULL); if (ret) goto out; ret = trace_test_buffer(&tr->max_buffer, &count); if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; goto out; } out: tracing_start(); out_no_start: trace->reset(tr); tr->max_latency = save_max; return ret; } #endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */ #ifdef CONFIG_NOP_TRACER int trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr) { /* What could possibly go wrong? */ return 0; } #endif #ifdef CONFIG_SCHED_TRACER struct wakeup_test_data { struct completion is_ready; int go; }; static int trace_wakeup_test_thread(void *data) { /* Make this a -deadline thread */ static const struct sched_attr attr = { .sched_policy = SCHED_DEADLINE, .sched_runtime = 100000ULL, .sched_deadline = 10000000ULL, .sched_period = 10000000ULL }; struct wakeup_test_data *x = data; sched_setattr(current, &attr); /* Make it know we have a new prio */ complete(&x->is_ready); /* now go to sleep and let the test wake us up */ set_current_state(TASK_INTERRUPTIBLE); while (!x->go) { schedule(); set_current_state(TASK_INTERRUPTIBLE); } complete(&x->is_ready); set_current_state(TASK_INTERRUPTIBLE); /* we are awake, now wait to disappear */ while (!kthread_should_stop()) { schedule(); set_current_state(TASK_INTERRUPTIBLE); } __set_current_state(TASK_RUNNING); return 0; } int trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) { unsigned long save_max = tr->max_latency; struct task_struct *p; struct wakeup_test_data data; unsigned long count; int ret; memset(&data, 0, sizeof(data)); init_completion(&data.is_ready); /* create a -deadline thread */ p = kthread_run(trace_wakeup_test_thread, &data, "ftrace-test"); if (IS_ERR(p)) { printk(KERN_CONT "Failed to create ftrace wakeup test thread "); return -1; } /* make sure the thread is running at -deadline policy */ wait_for_completion(&data.is_ready); /* start the tracing */ ret = tracer_init(trace, tr); if (ret) { warn_failed_init_tracer(trace, ret); return ret; } /* reset the max latency */ tr->max_latency = 0; while (p->on_rq) { /* * Sleep to make sure the -deadline thread is asleep too. * On virtual machines we can't rely on timings, * but we want to make sure this test still works. */ msleep(100); } init_completion(&data.is_ready); data.go = 1; /* memory barrier is in the wake_up_process() */ wake_up_process(p); /* Wait for the task to wake up */ wait_for_completion(&data.is_ready); /* stop the tracing. */ tracing_stop(); /* check both trace buffers */ ret = trace_test_buffer(&tr->array_buffer, NULL); if (!ret) ret = trace_test_buffer(&tr->max_buffer, &count); trace->reset(tr); tracing_start(); tr->max_latency = save_max; /* kill the thread */ kthread_stop(p); if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; } return ret; } #endif /* CONFIG_SCHED_TRACER */ #ifdef CONFIG_BRANCH_TRACER int trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr) { unsigned long count; int ret; /* start the tracing */ ret = tracer_init(trace, tr); if (ret) { warn_failed_init_tracer(trace, ret); return ret; } /* Sleep for a 1/10 of a second */ msleep(100); /* stop the tracing. */ tracing_stop(); /* check the trace buffer */ ret = trace_test_buffer(&tr->array_buffer, &count); trace->reset(tr); tracing_start(); if (!ret && !count) { printk(KERN_CONT ".. no entries found .."); ret = -1; } return ret; } #endif /* CONFIG_BRANCH_TRACER */