mirror of
https://github.com/torvalds/linux.git
synced 2024-12-22 10:56:40 +00:00
fdb6a8f4db
Impact: fix crash In case of losing samples struct op_entry could have been used uninitialized causing e.g. a wrong preemption count or NULL pointer access. This patch fixes this. Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
121 lines
2.8 KiB
C
121 lines
2.8 KiB
C
/**
|
|
* @file cpu_buffer.h
|
|
*
|
|
* @remark Copyright 2002-2009 OProfile authors
|
|
* @remark Read the file COPYING
|
|
*
|
|
* @author John Levon <levon@movementarian.org>
|
|
* @author Robert Richter <robert.richter@amd.com>
|
|
*/
|
|
|
|
#ifndef OPROFILE_CPU_BUFFER_H
|
|
#define OPROFILE_CPU_BUFFER_H
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/cache.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/ring_buffer.h>
|
|
|
|
struct task_struct;
|
|
|
|
int alloc_cpu_buffers(void);
|
|
void free_cpu_buffers(void);
|
|
|
|
void start_cpu_work(void);
|
|
void end_cpu_work(void);
|
|
|
|
/* CPU buffer is composed of such entries (which are
|
|
* also used for context switch notes)
|
|
*/
|
|
struct op_sample {
|
|
unsigned long eip;
|
|
unsigned long event;
|
|
unsigned long data[0];
|
|
};
|
|
|
|
struct op_entry;
|
|
|
|
struct oprofile_cpu_buffer {
|
|
unsigned long buffer_size;
|
|
struct task_struct *last_task;
|
|
int last_is_kernel;
|
|
int tracing;
|
|
unsigned long sample_received;
|
|
unsigned long sample_lost_overflow;
|
|
unsigned long backtrace_aborted;
|
|
unsigned long sample_invalid_eip;
|
|
int cpu;
|
|
struct delayed_work work;
|
|
};
|
|
|
|
DECLARE_PER_CPU(struct oprofile_cpu_buffer, cpu_buffer);
|
|
|
|
/*
|
|
* Resets the cpu buffer to a sane state.
|
|
*
|
|
* reset these to invalid values; the next sample collected will
|
|
* populate the buffer with proper values to initialize the buffer
|
|
*/
|
|
static inline void op_cpu_buffer_reset(int cpu)
|
|
{
|
|
struct oprofile_cpu_buffer *cpu_buf = &per_cpu(cpu_buffer, cpu);
|
|
|
|
cpu_buf->last_is_kernel = -1;
|
|
cpu_buf->last_task = NULL;
|
|
}
|
|
|
|
/*
|
|
* op_cpu_buffer_add_data() and op_cpu_buffer_write_commit() may be
|
|
* called only if op_cpu_buffer_write_reserve() did not return NULL or
|
|
* entry->event != NULL, otherwise entry->size or entry->event will be
|
|
* used uninitialized.
|
|
*/
|
|
|
|
struct op_sample
|
|
*op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size);
|
|
int op_cpu_buffer_write_commit(struct op_entry *entry);
|
|
struct op_sample *op_cpu_buffer_read_entry(struct op_entry *entry, int cpu);
|
|
unsigned long op_cpu_buffer_entries(int cpu);
|
|
|
|
/* returns the remaining free size of data in the entry */
|
|
static inline
|
|
int op_cpu_buffer_add_data(struct op_entry *entry, unsigned long val)
|
|
{
|
|
if (!entry->size)
|
|
return 0;
|
|
*entry->data = val;
|
|
entry->size--;
|
|
entry->data++;
|
|
return entry->size;
|
|
}
|
|
|
|
/* returns the size of data in the entry */
|
|
static inline
|
|
int op_cpu_buffer_get_size(struct op_entry *entry)
|
|
{
|
|
return entry->size;
|
|
}
|
|
|
|
/* returns 0 if empty or the size of data including the current value */
|
|
static inline
|
|
int op_cpu_buffer_get_data(struct op_entry *entry, unsigned long *val)
|
|
{
|
|
int size = entry->size;
|
|
if (!size)
|
|
return 0;
|
|
*val = *entry->data;
|
|
entry->size--;
|
|
entry->data++;
|
|
return size;
|
|
}
|
|
|
|
/* extra data flags */
|
|
#define KERNEL_CTX_SWITCH (1UL << 0)
|
|
#define IS_KERNEL (1UL << 1)
|
|
#define TRACE_BEGIN (1UL << 2)
|
|
#define USER_CTX_SWITCH (1UL << 3)
|
|
|
|
#endif /* OPROFILE_CPU_BUFFER_H */
|