[PATCH v5 1/4] tools/bootconfig: Fix errno reference after printf()

From: Masami Hiramatsu
Date: Thu Nov 19 2020 - 00:54:38 EST


Fix not to refer the errno variable as the result of previous libc
functions after printf() because printf() can change the errno.

Fixes: 85c46b78da58 ("bootconfig: Add bootconfig magic word for indicating bootconfig explicitly")
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
tools/bootconfig/main.c | 52 ++++++++++++++++++++++++++---------------------
1 file changed, 29 insertions(+), 23 deletions(-)

diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c
index eb92027817a7..52eb2bbe8966 100644
--- a/tools/bootconfig/main.c
+++ b/tools/bootconfig/main.c
@@ -147,6 +147,12 @@ static int load_xbc_file(const char *path, char **buf)
return ret;
}

+static int pr_errno(const char *msg, int err)
+{
+ pr_err("%s: %d\n", msg, err);
+ return err;
+}
+
static int load_xbc_from_initrd(int fd, char **buf)
{
struct stat stat;
@@ -162,26 +168,24 @@ static int load_xbc_from_initrd(int fd, char **buf)
if (stat.st_size < 8 + BOOTCONFIG_MAGIC_LEN)
return 0;

- if (lseek(fd, -BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0) {
- pr_err("Failed to lseek: %d\n", -errno);
- return -errno;
- }
+ if (lseek(fd, -BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0)
+ return pr_errno("Failed to lseek for magic", -errno);
+
if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0)
- return -errno;
+ return pr_errno("Failed to read", -errno);
+
/* Check the bootconfig magic bytes */
if (memcmp(magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN) != 0)
return 0;

- if (lseek(fd, -(8 + BOOTCONFIG_MAGIC_LEN), SEEK_END) < 0) {
- pr_err("Failed to lseek: %d\n", -errno);
- return -errno;
- }
+ if (lseek(fd, -(8 + BOOTCONFIG_MAGIC_LEN), SEEK_END) < 0)
+ return pr_errno("Failed to lseek for size", -errno);

if (read(fd, &size, sizeof(u32)) < 0)
- return -errno;
+ return pr_errno("Failed to read size", -errno);

if (read(fd, &csum, sizeof(u32)) < 0)
- return -errno;
+ return pr_errno("Failed to read checksum", -errno);

/* Wrong size error */
if (stat.st_size < size + 8 + BOOTCONFIG_MAGIC_LEN) {
@@ -190,10 +194,8 @@ static int load_xbc_from_initrd(int fd, char **buf)
}

if (lseek(fd, stat.st_size - (size + 8 + BOOTCONFIG_MAGIC_LEN),
- SEEK_SET) < 0) {
- pr_err("Failed to lseek: %d\n", -errno);
- return -errno;
- }
+ SEEK_SET) < 0)
+ return pr_errno("Failed to lseek", -errno);

ret = load_xbc_fd(fd, buf, size);
if (ret < 0)
@@ -262,14 +264,16 @@ static int show_xbc(const char *path, bool list)

ret = stat(path, &st);
if (ret < 0) {
- pr_err("Failed to stat %s: %d\n", path, -errno);
- return -errno;
+ ret = -errno;
+ pr_err("Failed to stat %s: %d\n", path, ret);
+ return ret;
}

fd = open(path, O_RDONLY);
if (fd < 0) {
- pr_err("Failed to open initrd %s: %d\n", path, fd);
- return -errno;
+ ret = -errno;
+ pr_err("Failed to open initrd %s: %d\n", path, ret);
+ return ret;
}

ret = load_xbc_from_initrd(fd, &buf);
@@ -307,8 +311,9 @@ static int delete_xbc(const char *path)

fd = open(path, O_RDWR);
if (fd < 0) {
- pr_err("Failed to open initrd %s: %d\n", path, fd);
- return -errno;
+ ret = -errno;
+ pr_err("Failed to open initrd %s: %d\n", path, ret);
+ return ret;
}

size = load_xbc_from_initrd(fd, &buf);
@@ -383,9 +388,10 @@ static int apply_xbc(const char *path, const char *xbc_path)
/* Apply new one */
fd = open(path, O_RDWR | O_APPEND);
if (fd < 0) {
- pr_err("Failed to open %s: %d\n", path, fd);
+ ret = -errno;
+ pr_err("Failed to open %s: %d\n", path, ret);
free(data);
- return fd;
+ return ret;
}
/* TODO: Ensure the @path is initramfs/initrd image */
ret = write(fd, data, size + 8);