x86, ds: add task tracing selftest

Add selftests to cover per-task branch tracing.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Cc: roland@redhat.com
Cc: eranian@googlemail.com
Cc: oleg@redhat.com
Cc: juan.villacis@intel.com
Cc: ak@linux.jf.intel.com
LKML-Reference: <20090403144600.329346000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/ds_selftest.c b/arch/x86/kernel/ds_selftest.c
index 599a96300628afff8fbebc294aeb489f66224cdf..a40b2533c71e662a34201028677ce45cd668408c 100644 (file)
--- a/arch/x86/kernel/ds_selftest.c
+++ b/arch/x86/kernel/ds_selftest.c
@@ -280,10 +280,51 @@ static int ds_selftest_bts_bad_release_noirq(int cpu,
        return error ? 0 : -1;
 }
 
+static int ds_selftest_bts_bad_request_cpu(int cpu, void *buffer)
+{
+       struct bts_tracer *tracer;
+       int error;
+
+       /* Try to request cpu tracing while task tracing is active. */
+       tracer = ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE, NULL,
+                                   (size_t)-1, BTS_KERNEL);
+       error = PTR_ERR(tracer);
+       if (!IS_ERR(tracer)) {
+               ds_release_bts(tracer);
+               error = 0;
+       }
+
+       if (error != -EPERM)
+               printk(KERN_CONT "cpu/task tracing overlap...");
+
+       return error ? 0 : -1;
+}
+
+static int ds_selftest_bts_bad_request_task(void *buffer)
+{
+       struct bts_tracer *tracer;
+       int error;
+
+       /* Try to request cpu tracing while task tracing is active. */
+       tracer = ds_request_bts_task(current, buffer, BUFFER_SIZE, NULL,
+                                   (size_t)-1, BTS_KERNEL);
+       error = PTR_ERR(tracer);
+       if (!IS_ERR(tracer)) {
+               error = 0;
+               ds_release_bts(tracer);
+       }
+
+       if (error != -EPERM)
+               printk(KERN_CONT "task/cpu tracing overlap...");
+
+       return error ? 0 : -1;
+}
+
 int ds_selftest_bts(void)
 {
        struct ds_selftest_bts_conf conf;
        unsigned char buffer[BUFFER_SIZE];
+       unsigned long irq;
        int cpu;
 
        printk(KERN_INFO "[ds] bts selftest...");
@@ -297,6 +338,8 @@ int ds_selftest_bts(void)
                        ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE,
                                           NULL, (size_t)-1, BTS_KERNEL);
                ds_selftest_bts_cpu(&conf);
+               if (conf.error >= 0)
+                       conf.error = ds_selftest_bts_bad_request_task(buffer);
                ds_release_bts(conf.tracer);
                if (conf.error < 0)
                        goto out;
@@ -315,12 +358,40 @@ int ds_selftest_bts(void)
                        if (conf.error < 0)
                                conf.tracer = NULL;
                }
+               if (conf.error >= 0)
+                       conf.error = ds_selftest_bts_bad_request_task(buffer);
                smp_call_function_single(cpu, ds_release_bts_noirq_wrap,
                                         conf.tracer, 1);
                if (conf.error < 0)
                        goto out;
        }
 
+       conf.suspend = ds_suspend_bts_wrap;
+       conf.resume = ds_resume_bts_wrap;
+       conf.tracer =
+               ds_request_bts_task(current, buffer, BUFFER_SIZE,
+                                   NULL, (size_t)-1, BTS_KERNEL);
+       ds_selftest_bts_cpu(&conf);
+       if (conf.error >= 0)
+               conf.error = ds_selftest_bts_bad_request_cpu(0, buffer);
+       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_task(current, buffer, BUFFER_SIZE,
+                                  NULL, (size_t)-1, BTS_KERNEL);
+       local_irq_save(irq);
+       ds_selftest_bts_cpu(&conf);
+       if (conf.error >= 0)
+               conf.error = ds_selftest_bts_bad_request_cpu(0, buffer);
+       ds_release_bts_noirq(conf.tracer);
+       local_irq_restore(irq);
+       if (conf.error < 0)
+               goto out;
+
        conf.error = 0;
  out:
        put_online_cpus();