linux-imx

// SPDX-License-Identifier: GPL-2.0

#define pr_fmt(fmt) "kcov: " fmt

​

#define DISABLE_BRANCH_PROFILING

#include <linux/atomic.h>

#include <linux/compiler.h>

#include <linux/errno.h>

#include <linux/export.h>

#include <linux/types.h>

#include <linux/file.h>

#include <linux/fs.h>

#include <linux/init.h>

#include <linux/mm.h>

#include <linux/preempt.h>

#include <linux/printk.h>

#include <linux/sched.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

#include <linux/vmalloc.h>

#include <linux/debugfs.h>

#include <linux/uaccess.h>

#include <linux/kcov.h>

#include <linux/refcount.h>

#include <asm/setup.h>

​

/* Number of 64-bit words written per one comparison: */

#define KCOV_WORDS_PER_CMP 4

​

/*

 * kcov descriptor (one per opened debugfs file).

 * State transitions of the descriptor:

 *  - initial state after open()

 *  - then there must be a single ioctl(KCOV_INIT_TRACE) call

 *  - then, mmap() call (several calls are allowed but not useful)

 *  - then, ioctl(KCOV_ENABLE, arg), where arg is

 *  KCOV_TRACE_PC - to trace only the PCs

 *  or

 *  KCOV_TRACE_CMP - to trace only the comparison operands

 *  - then, ioctl(KCOV_DISABLE) to disable the task.

 * Enabling/disabling ioctls can be repeated (only one task a time allowed).

 */

struct kcov {

    /*

     * Reference counter. We keep one for:

     *  - opened file descriptor

     *  - task with enabled coverage (we can't unwire it from another task)

     */

    refcount_t      refcount;

    /* The lock protects mode, size, area and t. */

    spinlock_t      lock;

    enum kcov_mode      mode;

    /* Size of arena (in long's for KCOV_MODE_TRACE). */

    unsigned        size;

    /* Coverage buffer shared with user space. */

    void            *area;

    /* Task for which we collect coverage, or NULL. */

    struct task_struct  *t;

};

​

static notrace bool check_kcov_mode(enum kcov_mode needed_mode, struct task_struct *t)

{

    unsigned int mode;

​