diff options
| -rw-r--r-- | include/linux/ftrace.h | 2 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 19 | ||||
| -rw-r--r-- | kernel/trace/trace_selftest.c | 113 |
3 files changed, 130 insertions, 4 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 953a36d6a199..a842d96c6343 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -55,6 +55,7 @@ struct dyn_ftrace { }; int ftrace_force_update(void); +void ftrace_set_filter(unsigned char *buf, int len, int reset); /* defined in arch */ extern int ftrace_ip_converted(unsigned long ip); @@ -70,6 +71,7 @@ extern void ftrace_call(void); extern void mcount_call(void); #else # define ftrace_force_update() ({ 0; }) +# define ftrace_set_filter(buf, len, reset) do { } while (0) #endif static inline void tracer_disable(void) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 6d4d2e86debc..5e9389faaf75 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1010,6 +1010,25 @@ ftrace_filter_write(struct file *file, const char __user *ubuf, return ret; } +/** + * ftrace_set_filter - set a function to filter on in ftrace + * @buf - the string that holds the function filter text. + * @len - the length of the string. + * @reset - non zero to reset all filters before applying this filter. + * + * Filters denote which functions should be enabled when tracing is enabled. + * If @buf is NULL and reset is set, all functions will be enabled for tracing. + */ +notrace void ftrace_set_filter(unsigned char *buf, int len, int reset) +{ + mutex_lock(&ftrace_filter_lock); + if (reset) + ftrace_filter_reset(); + if (buf) + ftrace_match(buf, len); + mutex_unlock(&ftrace_filter_lock); +} + static int notrace ftrace_filter_release(struct inode *inode, struct file *file) { diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index c01874c3b1f9..4c8a1b2d8231 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -99,6 +99,100 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) } #ifdef CONFIG_FTRACE + +#ifdef CONFIG_DYNAMIC_FTRACE + +#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func +#define __STR(x) #x +#define STR(x) __STR(x) +static int DYN_FTRACE_TEST_NAME(void) +{ + /* used to call mcount */ + return 0; +} + +/* Test dynamic code modification and ftrace filters */ +int trace_selftest_startup_dynamic_tracing(struct tracer *trace, + struct trace_array *tr, + int (*func)(void)) +{ + unsigned long count; + int ret; + int save_ftrace_enabled = ftrace_enabled; + int save_tracer_enabled = tracer_enabled; + + /* The ftrace test PASSED */ + printk(KERN_CONT "PASSED\n"); + pr_info("Testing dynamic ftrace: "); + + /* enable tracing, and record the filter function */ + ftrace_enabled = 1; + tracer_enabled = 1; + + /* passed in by parameter to fool gcc from optimizing */ + func(); + + /* update the records */ + ret = ftrace_force_update(); + if (ret) { + printk(KERN_CONT ".. ftraced failed .. "); + return ret; + } + + /* filter only on our function */ + ftrace_set_filter(STR(DYN_FTRACE_TEST_NAME), + sizeof(STR(DYN_FTRACE_TEST_NAME)), 1); + + /* enable tracing */ + tr->ctrl = 1; + trace->init(tr); + /* Sleep for a 1/10 of a second */ + msleep(100); + + /* we should have nothing in the buffer */ + ret = trace_test_buffer(tr, &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. */ + tr->ctrl = 0; + trace->ctrl_update(tr); + ftrace_enabled = 0; + + /* check the trace buffer */ + ret = trace_test_buffer(tr, &count); + trace->reset(tr); + + /* we should only have one item */ + if (!ret && count != 1) { + printk(KERN_CONT ".. filter failed .."); + ret = -1; + goto out; + } + out: + ftrace_enabled = save_ftrace_enabled; + tracer_enabled = save_tracer_enabled; + + /* Enable tracing on all functions again */ + ftrace_set_filter(NULL, 0, 1); + + return ret; +} +#else +# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; }) +#endif /* CONFIG_DYNAMIC_FTRACE */ /* * Simple verification test of ftrace function tracer. * Enable ftrace, sleep 1/10 second, and then read the trace @@ -109,8 +203,13 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) { unsigned long count; int ret; + int save_ftrace_enabled = ftrace_enabled; + int save_tracer_enabled = tracer_enabled; - /* make sure functions have been recorded */ + /* make sure msleep has been recorded */ + msleep(1); + + /* force the recorded functions to be traced */ ret = ftrace_force_update(); if (ret) { printk(KERN_CONT ".. ftraced failed .. "); @@ -119,6 +218,7 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) /* start the tracing */ ftrace_enabled = 1; + tracer_enabled = 1; tr->ctrl = 1; trace->init(tr); @@ -136,8 +236,16 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) 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); + + out: + ftrace_enabled = save_ftrace_enabled; + tracer_enabled = save_tracer_enabled; + return ret; } #endif /* CONFIG_FTRACE */ @@ -415,6 +523,3 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr return ret; } #endif /* CONFIG_CONTEXT_SWITCH_TRACER */ - -#ifdef CONFIG_DYNAMIC_FTRACE -#endif /* CONFIG_DYNAMIC_FTRACE */ |