/*
* Reads on sysfs are handled through seq_file, which takes care of hairy
* details like buffering and seeking. The following function pipes
* sysfs_ops->show() result through seq_file.
*/
static int sysfs_seq_show(struct seq_file *sf, void *v)
{
struct sysfs_open_file *of = sf->private;
struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
const struct sysfs_ops *ops;
char *buf;
ssize_t count;
/* acquire buffer and ensure that it's >= PAGE_SIZE */
count = seq_get_buf(sf, &buf);
if (count < PAGE_SIZE) {
seq_commit(sf, -1);
return 0;
}
/*
* Need @of->sd for attr and ops, its parent for kobj. @of->mutex
* nests outside active ref and is just to ensure that the ops
* aren't called concurrently for the same open file.
*/
mutex_lock(&of->mutex);
if (!sysfs_get_active(of->sd)) {
mutex_unlock(&of->mutex);
return -ENODEV;
}
of->event = atomic_read(&of->sd->s_attr.open->event);
/*
* Lookup @ops and invoke show(). Control may reach here via seq
* file lseek even if @ops->show() isn't implemented.
*/
ops = sysfs_file_ops(of->sd);
if (ops->show)
count = ops->show(kobj, of->sd->s_attr.attr, buf);
else
count = 0;
sysfs_put_active(of->sd);
mutex_unlock(&of->mutex);
if (count < 0)
return count;
/*
* The code works fine with PAGE_SIZE return but it's likely to
* indicate truncated result or overflow in normal use cases.
*/
if (count >= (ssize_t)PAGE_SIZE) {
print_symbol("fill_read_buffer: %s returned bad count\n",
(unsigned long)ops->show);
/* Try to struggle along */
count = PAGE_SIZE - 1;
}
seq_commit(sf, count);
return 0;
}
/*
* Reads on sysfs are handled through seq_file, which takes care of hairy
* details like buffering and seeking. The following function pipes
* sysfs_ops->show() result through seq_file.
*/
static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
{
struct kernfs_open_file *of = sf->private;
struct kobject *kobj = of->kn->parent->priv;
const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
ssize_t count;
char *buf;
/* acquire buffer and ensure that it's >= PAGE_SIZE and clear */
count = seq_get_buf(sf, &buf);
if (count < PAGE_SIZE) {
seq_commit(sf, -1);
return 0;
}
memset(buf, 0, PAGE_SIZE);
/*
* Invoke show(). Control may reach here via seq file lseek even
* if @ops->show() isn't implemented.
*/
if (ops->show) {
count = ops->show(kobj, of->kn->priv, buf);
if (count < 0)
return count;
}
/*
* The code works fine with PAGE_SIZE return but it's likely to
* indicate truncated result or overflow in normal use cases.
*/
if (count >= (ssize_t)PAGE_SIZE) {
print_symbol("fill_read_buffer: %s returned bad count\n",
(unsigned long)ops->show);
/* Try to struggle along */
count = PAGE_SIZE - 1;
}
seq_commit(sf, count);
return 0;
}
static inline void task_name(struct seq_file *m, struct task_struct *p)
{
char *buf;
size_t size;
char tcomm[sizeof(p->comm)];
int ret;
get_task_comm(tcomm, p);
seq_puts(m, "Name:\t");
size = seq_get_buf(m, &buf);
ret = string_escape_str(tcomm, buf, size, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
seq_commit(m, ret < size ? ret : -1);
seq_putc(m, '\n');
}
static int mali_seq_internal_state_show(struct seq_file *seq_file, void *v)
{
u32 len = 0;
u32 size;
char *buf;
size = seq_get_buf(seq_file, &buf);
if (!size) {
return -ENOMEM;
}
/* Create the internal state dump. */
len = snprintf(buf + len, size - len, "Mali device driver %s\n", SVN_REV_STRING);
len += snprintf(buf + len, size - len, "License: %s\n\n", MALI_KERNEL_LINUX_LICENSE);
len += _mali_kernel_core_dump_state(buf + len, size - len);
seq_commit(seq_file, len);
return 0;
}
void proc_task_name(struct seq_file *m, struct task_struct *p, bool escape)
{
char *buf;
size_t size;
char tcomm[64];
int ret;
if (p->flags & PF_WQ_WORKER)
wq_worker_comm(tcomm, sizeof(tcomm), p);
else
__get_task_comm(tcomm, sizeof(tcomm), p);
size = seq_get_buf(m, &buf);
if (escape) {
ret = string_escape_str(tcomm, buf, size,
ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
if (ret >= size)
ret = -1;
} else {
ret = strscpy(buf, tcomm, size);
}
seq_commit(m, ret);
}
