diff options
Diffstat (limited to 'arch/arm/kernel/etm.c')
-rw-r--r-- | arch/arm/kernel/etm.c | 51 |
1 files changed, 49 insertions, 2 deletions
diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c index af2a38b4f93a..7db3247b2187 100644 --- a/arch/arm/kernel/etm.c +++ b/arch/arm/kernel/etm.c @@ -124,6 +124,9 @@ static int trace_start_etm(struct tracectx *t, int id) if (t->flags & TRACER_TIMESTAMP) v |= ETMCTRL_TIMESTAMP_EN; + if (t->flags & TRACER_RETURN_STACK) + v |= ETMCTRL_RETURN_STACK_EN; + etm_unlock(t, id); etm_writel(t, id, v, ETMR_CTRL); @@ -703,10 +706,13 @@ static ssize_t trace_branch_output_store(struct kobject *kobj, return -EINVAL; mutex_lock(&tracer.mutex); - if (branch_output) + if (branch_output) { tracer.flags |= TRACER_BRANCHOUTPUT; - else + /* Branch broadcasting is incompatible with the return stack */ + tracer.flags &= ~TRACER_RETURN_STACK; + } else { tracer.flags &= ~TRACER_BRANCHOUTPUT; + } mutex_unlock(&tracer.mutex); return n; @@ -716,6 +722,39 @@ static struct kobj_attribute trace_branch_output_attr = __ATTR(trace_branch_output, 0644, trace_branch_output_show, trace_branch_output_store); +static ssize_t trace_return_stack_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", !!(tracer.flags & TRACER_RETURN_STACK)); +} + +static ssize_t trace_return_stack_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t n) +{ + unsigned int return_stack; + + if (sscanf(buf, "%u", &return_stack) != 1) + return -EINVAL; + + mutex_lock(&tracer.mutex); + if (return_stack) { + tracer.flags |= TRACER_RETURN_STACK; + /* Return stack is incompatible with branch broadcasting */ + tracer.flags &= ~TRACER_BRANCHOUTPUT; + } else { + tracer.flags &= ~TRACER_RETURN_STACK; + } + mutex_unlock(&tracer.mutex); + + return n; +} + +static struct kobj_attribute trace_return_stack_attr = + __ATTR(trace_return_stack, 0644, + trace_return_stack_show, trace_return_stack_store); + static ssize_t trace_timestamp_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) @@ -900,6 +939,14 @@ static int etm_probe(struct amba_device *dev, const struct amba_id *id) dev_dbg(&dev->dev, "Failed to create trace_branch_output in sysfs\n"); + if (etmccer & ETMCCER_RETURN_STACK_IMPLEMENTED) { + ret = sysfs_create_file(&dev->dev.kobj, + &trace_return_stack_attr.attr); + if (ret) + dev_dbg(&dev->dev, + "Failed to create trace_return_stack in sysfs\n"); + } + if (etmccer & ETMCCER_TIMESTAMPING_IMPLEMENTED) { ret = sysfs_create_file(&dev->dev.kobj, &trace_timestamp_attr.attr); |