Messages in this thread | | | Date | Wed, 18 Nov 2020 11:04:37 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH v4 2/4] tools/bootconfig: Fix to check the write failure correctly |
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On Thu, 19 Nov 2020 00:35:35 +0900 Masami Hiramatsu <mhiramat@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 <torvalds@linux-foundation.org> > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> > Tested-by: Chen Yu <yu.chen.surf@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: > + if (ftruncate(fd, stat.st_size) < 0) {
If the first write fails (doesn't modify the initrd), and then this fails, you will show a message of: "may be corrupted. Recommend to rebuild", when that would not be the case. Should a test of the size be done again, to see if it is already the same?
out_rollback: old_size = stat.st_size; if (stat(fd, &stat) < 0) /* Shouldn't happen, it worked once before */ goto print_error;
if (old_size < stat.st_size) if (ftruncate(fd, old_size) < 0) goto print_error;
goto out;
print_error:
> + 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)
-- Steve
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