On Thu, 19 Nov 2020 00:35:35 +0900
Masami Hiramatsu <mhira...@kernel.org> wrote:
> Fix to check the write(2) failure including partial write
> correctly and try to rollback the partial write, because
> if there is no BOOTCONFIG_MAGIC string, we can not remove it.
>
> Fixes: 85c46b78da58 ("bootconfig: Add bootconfig magic word for indicating
> bootconfig explicitly")
> Suggested-by: Linus Torvalds <torva...@linux-foundation.org>
> Signed-off-by: Masami Hiramatsu <mhira...@kernel.org>
> Tested-by: Chen Yu <yu.chen.s...@gmail.com>
> ---
> tools/bootconfig/main.c | 27 +++++++++++++++++++++++----
> 1 file changed, 23 insertions(+), 4 deletions(-)
>
> diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c
> index 52eb2bbe8966..905bfaefae35 100644
> --- a/tools/bootconfig/main.c
> +++ b/tools/bootconfig/main.c
> @@ -337,6 +337,7 @@ static int delete_xbc(const char *path)
>
> static int apply_xbc(const char *path, const char *xbc_path)
> {
> + struct stat stat;
> u32 size, csum;
> char *buf, *data;
> int ret, fd;
> @@ -394,16 +395,26 @@ static int apply_xbc(const char *path, const char
> *xbc_path)
> return ret;
> }
> /* TODO: Ensure the @path is initramfs/initrd image */
> + if (fstat(fd, &stat) < 0) {
> + pr_err("Failed to get the size of %s\n", path);
> + goto out;
> + }
> ret = write(fd, data, size + 8);
> - if (ret < 0) {
> + if (ret < size + 8) {
> + if (ret < 0)
> + ret = -errno;
> pr_err("Failed to apply a boot config: %d\n", ret);
> - goto out;
> + if (ret < 0)
> + goto out;
> + goto out_rollback;
> }
> /* Write a magic word of the bootconfig */
> ret = write(fd, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
> - if (ret < 0) {
> + if (ret < BOOTCONFIG_MAGIC_LEN) {
> + if (ret < 0)
> + ret = -errno;
> pr_err("Failed to apply a boot config magic: %d\n", ret);
> - goto out;
> + goto out_rollback;
> }
> ret = 0;
> out:
> @@ -411,6 +422,14 @@ static int apply_xbc(const char *path, const char
> *xbc_path)
> free(data);
>
> return ret;
> +
> +out_rollback:
Oops, I forgot to set error to return value here.
I'll fix that.
Thank you,
> + if (ftruncate(fd, stat.st_size) < 0) {
> + ret = -errno;
> + pr_err("Failed to rollback the write error: %d\n", ret);
> + pr_err("The initrd %s may be corrupted. Recommend to
> rebuild.\n", path);
> + }
> + goto out;
> }
>
> static int usage(void)
>
--
Masami Hiramatsu <mhira...@kernel.org>
