Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
#include "cache.h"
#include "debug.h"
#include "strbuf.h"
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/zalloc.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
 
/*
 * Used as the default ->buf value, so that people can always assume
 * buf is non NULL and ->buf is NUL terminated even for a freshly
 * initialized strbuf.
 */
char strbuf_slopbuf[1];
 
int strbuf_init(struct strbuf *sb, ssize_t hint)
{
<------>sb->alloc = sb->len = 0;
<------>sb->buf = strbuf_slopbuf;
<------>if (hint)
<------><------>return strbuf_grow(sb, hint);
<------>return 0;
}
 
void strbuf_release(struct strbuf *sb)
{
<------>if (sb->alloc) {
<------><------>zfree(&sb->buf);
<------><------>strbuf_init(sb, 0);
<------>}
}
 
char *strbuf_detach(struct strbuf *sb, size_t *sz)
{
<------>char *res = sb->alloc ? sb->buf : NULL;
<------>if (sz)
<------><------>*sz = sb->len;
<------>strbuf_init(sb, 0);
<------>return res;
}
 
int strbuf_grow(struct strbuf *sb, size_t extra)
{
<------>char *buf;
<------>size_t nr = sb->len + extra + 1;
 
<------>if (nr < sb->alloc)
<------><------>return 0;
 
<------>if (nr <= sb->len)
<------><------>return -E2BIG;
 
<------>if (alloc_nr(sb->alloc) > nr)
<------><------>nr = alloc_nr(sb->alloc);
 
<------>/*
<------> * Note that sb->buf == strbuf_slopbuf if sb->alloc == 0, and it is
<------> * a static variable. Thus we have to avoid passing it to realloc.
<------> */
<------>buf = realloc(sb->alloc ? sb->buf : NULL, nr * sizeof(*buf));
<------>if (!buf)
<------><------>return -ENOMEM;
 
<------>sb->buf = buf;
<------>sb->alloc = nr;
<------>return 0;
}
 
int strbuf_addch(struct strbuf *sb, int c)
{
<------>int ret = strbuf_grow(sb, 1);
<------>if (ret)
<------><------>return ret;
 
<------>sb->buf[sb->len++] = c;
<------>sb->buf[sb->len] = '\0';
<------>return 0;
}
 
int strbuf_add(struct strbuf *sb, const void *data, size_t len)
{
<------>int ret = strbuf_grow(sb, len);
<------>if (ret)
<------><------>return ret;
 
<------>memcpy(sb->buf + sb->len, data, len);
<------>return strbuf_setlen(sb, sb->len + len);
}
 
static int strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap)
{
<------>int len, ret;
<------>va_list ap_saved;
 
<------>if (!strbuf_avail(sb)) {
<------><------>ret = strbuf_grow(sb, 64);
<------><------>if (ret)
<------><------><------>return ret;
<------>}
 
<------>va_copy(ap_saved, ap);
<------>len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
<------>if (len < 0) {
<------><------>va_end(ap_saved);
<------><------>return len;
<------>}
<------>if (len > strbuf_avail(sb)) {
<------><------>ret = strbuf_grow(sb, len);
<------><------>if (ret) {
<------><------><------>va_end(ap_saved);
<------><------><------>return ret;
<------><------>}
<------><------>len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved);
<------><------>if (len > strbuf_avail(sb)) {
<------><------><------>pr_debug("this should not happen, your vsnprintf is broken");
<------><------><------>va_end(ap_saved);
<------><------><------>return -EINVAL;
<------><------>}
<------>}
<------>va_end(ap_saved);
<------>return strbuf_setlen(sb, sb->len + len);
}
 
int strbuf_addf(struct strbuf *sb, const char *fmt, ...)
{
<------>va_list ap;
<------>int ret;
 
<------>va_start(ap, fmt);
<------>ret = strbuf_addv(sb, fmt, ap);
<------>va_end(ap);
<------>return ret;
}
 
ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
{
<------>size_t oldlen = sb->len;
<------>size_t oldalloc = sb->alloc;
<------>int ret;
 
<------>ret = strbuf_grow(sb, hint ? hint : 8192);
<------>if (ret)
<------><------>return ret;
 
<------>for (;;) {
<------><------>ssize_t cnt;
 
<------><------>cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
<------><------>if (cnt < 0) {
<------><------><------>if (oldalloc == 0)
<------><------><------><------>strbuf_release(sb);
<------><------><------>else
<------><------><------><------>strbuf_setlen(sb, oldlen);
<------><------><------>return cnt;
<------><------>}
<------><------>if (!cnt)
<------><------><------>break;
<------><------>sb->len += cnt;
<------><------>ret = strbuf_grow(sb, 8192);
<------><------>if (ret)
<------><------><------>return ret;
<------>}
 
<------>sb->buf[sb->len] = '\0';
<------>return sb->len - oldlen;
}