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>

1 files changed, 71 insertions, 0 deletions

diff --git a/arch/x86/kernel/ds_selftest.c b/arch/x86/kernel/ds_selftest.c
index 599a96300628..a40b2533c71e 100644
--- 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();