Perform debug store selftests on each cpu. Cover both the normal and the _noirq variant of the debug store interface. Signed-off-by: Markus Metzger --- arch/x86/kernel/ds_selftest.c | 186 137 + 49 - 0 ! 1 file changed, 137 insertions(+), 49 deletions(-) Index: b/arch/x86/kernel/ds_selftest.c =================================================================== --- a/arch/x86/kernel/ds_selftest.c +++ b/arch/x86/kernel/ds_selftest.c @@ -11,13 +11,21 @@ #include #include #include +#include #include -#define BUFFER_SIZE 1021 /* Intentionally chose an odd size. */ +#define BUFFER_SIZE 521 /* Intentionally chose an odd size. */ +struct ds_selftest_bts_conf { + struct bts_tracer *tracer; + int error; + int (*suspend)(struct bts_tracer *); + int (*resume)(struct bts_tracer *); +}; + static int ds_selftest_bts_consistency(const struct bts_trace *trace) { int error = 0; @@ -125,36 +133,32 @@ static int ds_selftest_bts_read(struct b return 0; } -int ds_selftest_bts(void) +static void ds_selftest_bts_cpu(void *arg) { + struct ds_selftest_bts_conf *conf = arg; const struct bts_trace *trace; - struct bts_tracer *tracer; - int error = 0; void *top; - unsigned char buffer[BUFFER_SIZE]; - printk(KERN_INFO "[ds] bts selftest..."); - - tracer = ds_request_bts_cpu(smp_processor_id(), buffer, BUFFER_SIZE, - NULL, (size_t)-1, BTS_KERNEL); - if (IS_ERR(tracer)) { - error = PTR_ERR(tracer); - tracer = NULL; + if (IS_ERR(conf->tracer)) { + conf->error = PTR_ERR(conf->tracer); + conf->tracer = NULL; printk(KERN_CONT - "initialization failed (err: %d)...", error); - goto out; + "initialization failed (err: %d)...", conf->error); + return; } - /* The return should already give us enough trace. */ - ds_suspend_bts(tracer); + /* We should meanwhile have enough trace. */ + conf->error = conf->suspend(conf->tracer); + if (conf->error < 0) + return; /* Let's see if we can access the trace. */ - trace = ds_read_bts(tracer); + trace = ds_read_bts(conf->tracer); - error = ds_selftest_bts_consistency(trace); - if (error < 0) - goto out; + conf->error = ds_selftest_bts_consistency(trace); + if (conf->error < 0) + return; /* If everything went well, we should have a few trace entries. */ if (trace->ds.top == trace->ds.begin) { @@ -168,10 +172,11 @@ int ds_selftest_bts(void) } /* Let's try to read the trace we collected. */ - error = ds_selftest_bts_read(tracer, trace, + conf->error = + ds_selftest_bts_read(conf->tracer, trace, trace->ds.begin, trace->ds.top); - if (error < 0) - goto out; + if (conf->error < 0) + return; /* * Let's read the trace again. @@ -179,26 +184,31 @@ int ds_selftest_bts(void) */ top = trace->ds.top; - trace = ds_read_bts(tracer); - error = ds_selftest_bts_consistency(trace); - if (error < 0) - goto out; + trace = ds_read_bts(conf->tracer); + conf->error = ds_selftest_bts_consistency(trace); + if (conf->error < 0) + return; if (top != trace->ds.top) { printk(KERN_CONT "suspend not working..."); - error = -1; - goto out; + conf->error = -1; + return; } /* Let's collect some more trace - see if resume is working. */ - ds_resume_bts(tracer); - ds_suspend_bts(tracer); - - trace = ds_read_bts(tracer); - - error = ds_selftest_bts_consistency(trace); - if (error < 0) - goto out; + conf->error = conf->resume(conf->tracer); + if (conf->error < 0) + return; + + conf->error = conf->suspend(conf->tracer); + if (conf->error < 0) + return; + + trace = ds_read_bts(conf->tracer); + + conf->error = ds_selftest_bts_consistency(trace); + if (conf->error < 0) + return; if (trace->ds.top == top) { /* @@ -210,35 +220,113 @@ int ds_selftest_bts(void) printk(KERN_CONT "no resume progress/overflow..."); - error = ds_selftest_bts_read(tracer, trace, + conf->error = + ds_selftest_bts_read(conf->tracer, trace, trace->ds.begin, trace->ds.end); } else if (trace->ds.top < top) { /* * We had a buffer overflow - the entire buffer should * contain trace records. */ - error = ds_selftest_bts_read(tracer, trace, + conf->error = + ds_selftest_bts_read(conf->tracer, trace, trace->ds.begin, trace->ds.end); } else { /* * It is quite likely that the buffer did not overflow. * Let's just check the delta trace. */ - error = ds_selftest_bts_read(tracer, trace, - top, trace->ds.top); + conf->error = + ds_selftest_bts_read(conf->tracer, trace, top, + trace->ds.top); } - if (error < 0) - goto out; + if (conf->error < 0) + return; - error = 0; + conf->error = 0; +} - /* The final test: release the tracer while tracing is suspended. */ - out: - ds_release_bts(tracer); +static int ds_suspend_bts_wrap(struct bts_tracer *tracer) +{ + ds_suspend_bts(tracer); + return 0; +} - printk(KERN_CONT "%s.\n", (error ? "failed" : "passed")); +static int ds_resume_bts_wrap(struct bts_tracer *tracer) +{ + ds_resume_bts(tracer); + return 0; +} - return error; +static void ds_release_bts_noirq_wrap(void *tracer) +{ + (void)ds_release_bts_noirq(tracer); +} + +static int ds_selftest_bts_bad_release_noirq(int cpu, + struct bts_tracer *tracer) +{ + int error = -EPERM; + + /* Try to release the tracer on the wrong cpu. */ + get_cpu(); + if (cpu != smp_processor_id()) { + error = ds_release_bts_noirq(tracer); + if (error != -EPERM) + printk(KERN_CONT "release on wrong cpu..."); + } + put_cpu(); + + return error ? 0 : -1; +} + +int ds_selftest_bts(void) +{ + struct ds_selftest_bts_conf conf; + unsigned char buffer[BUFFER_SIZE]; + int cpu; + + printk(KERN_INFO "[ds] bts selftest..."); + conf.error = 0; + + get_online_cpus(); + for_each_online_cpu(cpu) { + conf.suspend = ds_suspend_bts_wrap; + conf.resume = ds_resume_bts_wrap; + conf.tracer = + ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE, + NULL, (size_t)-1, BTS_KERNEL); + ds_selftest_bts_cpu(&conf); + ds_release_bts(conf.tracer); + if (conf.error < 0) + goto out; + + conf.suspend = ds_suspend_bts_noirq; + conf.resume = ds_resume_bts_noirq; + conf.tracer = + ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE, + NULL, (size_t)-1, BTS_KERNEL); + smp_call_function_single(cpu, ds_selftest_bts_cpu, &conf, 1); + if (conf.error >= 0) { + conf.error = + ds_selftest_bts_bad_release_noirq(cpu, + conf.tracer); + /* We must not release the tracer twice. */ + if (conf.error < 0) + conf.tracer = NULL; + } + smp_call_function_single(cpu, ds_release_bts_noirq_wrap, + conf.tracer, 1); + if (conf.error < 0) + goto out; + } + + conf.error = 0; + out: + put_online_cpus(); + printk(KERN_CONT "%s.\n", (conf.error ? "failed" : "passed")); + + return conf.error; } int ds_selftest_pebs(void) --