/*
* Add samples with data to the ring buffer.
*
* Use oprofile_add_data(&entry, val) to add data and
* oprofile_write_commit(&entry) to commit the sample.
*/
void
oprofile_write_reserve(struct op_entry *entry, struct pt_regs * const regs,
unsigned long pc, int code, int size)
{
struct op_sample *sample;
int is_kernel = !user_mode(regs);
struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
cpu_buf->sample_received++;
/* no backtraces for samples with data */
if (op_add_code(cpu_buf, 0, is_kernel, current))
goto fail;
sample = op_cpu_buffer_write_reserve(entry, size + 2);
if (!sample)
goto fail;
sample->eip = ESCAPE_CODE;
sample->event = 0; /* no flags */
op_cpu_buffer_add_data(entry, code);
op_cpu_buffer_add_data(entry, pc);
return;
fail:
entry->event = NULL;
cpu_buf->sample_lost_overflow++;
}
int oprofile_add_data64(struct op_entry *entry, u64 val)
{
if (!entry->event)
return 0;
if (op_cpu_buffer_get_size(entry) < 2)
return 0;
if (!op_cpu_buffer_add_data(entry, (u32)val))
return 0;
return op_cpu_buffer_add_data(entry, (u32)(val >> 32));
}
static int
op_add_code(struct oprofile_cpu_buffer *cpu_buf, unsigned long backtrace,
int is_kernel, struct task_struct *task)
{
struct op_entry entry;
struct op_sample *sample;
unsigned long flags;
int size;
flags = 0;
if (backtrace)
flags |= TRACE_BEGIN;
/* notice a switch from user->kernel or vice versa */
is_kernel = !!is_kernel;
if (cpu_buf->last_is_kernel != is_kernel) {
cpu_buf->last_is_kernel = is_kernel;
flags |= KERNEL_CTX_SWITCH;
if (is_kernel)
flags |= IS_KERNEL;
}
/* notice a task switch */
if (cpu_buf->last_task != task) {
cpu_buf->last_task = task;
flags |= USER_CTX_SWITCH;
}
if (!flags)
/* nothing to do */
return 0;
if (flags & USER_CTX_SWITCH)
size = 1;
else
size = 0;
sample = op_cpu_buffer_write_reserve(&entry, size);
if (!sample)
return -ENOMEM;
sample->eip = ESCAPE_CODE;
sample->event = flags;
if (size)
op_cpu_buffer_add_data(&entry, (unsigned long)task);
op_cpu_buffer_write_commit(&entry);
return 0;
}
int oprofile_add_data64(struct op_entry *entry, u64 val)
{
if (!entry->event)
return 0;
if (op_cpu_buffer_get_size(entry) < 2)
/*
* the function returns 0 to indicate a too small
* buffer, even if there is some space left
*/
return 0;
if (!op_cpu_buffer_add_data(entry, (u32)val))
return 0;
return op_cpu_buffer_add_data(entry, (u32)(val >> 32));
}
int oprofile_add_data(struct op_entry *entry, unsigned long val)
{
if (!entry->event)
return 0;
return op_cpu_buffer_add_data(entry, val);
}