Re: [PATCH] bootconfig: Fix missing return check of xbc_node_compose_key function

[Masami Hiramatsu]

Hi,

On Tue, 31 Aug 2021 16:40:46 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> On Tue, 31 Aug 2021 00:32:56 -0300
> Julio Faracco <jcfaracco@xxxxxxxxx> wrote:
> 
> > The function `xbc_show_list should` handle the keys during the
> > composition. Even the errors returned by the compose function. Instead
> > of removing the `ret` variable, it should save the value and show the
> > exact error. This missing variable is causing a compilation issue also.
> > 
> 
> Oops, good catch! Hmm, I missed some intermediate patch for some commit.
> Let me check.

OK, I found this is a bug introduced when mergeing the patch.

This bug has been introduced by
[1] commit e5efaeb8a8f5 ("bootconfig: Support mixing a value and subkeys under a key")

However the original post of the patch (Linked from the above commit)

https://lkml.kernel.org/r/162262194685.264090.7738574774030567419.stgit@devnote2

seems correct, because 'ret' local variable exists in xbc_show_list().
However, this 'ret' has been removed in Apr, by 

[2] commit 30d103f2d460 ("tools/bootconfig: Simplify expression")

So I think it is merge timing issue... When I wrote [1], [2] was not
on my working tree (I forgot it, sorry). But when we merge [1], 
[2] was Steve's tree, and caused this issue.

Anyway, thank you for reporting!

Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Fixes: e5efaeb8a8f5 ("bootconfig: Support mixing a value and subkeys under a key")
Cc: stable@xxxxxxxxxxxxxxx

Thank you!

> 
> > Signed-off-by: Julio Faracco <jcfaracco@xxxxxxxxx>
> > ---
> >  tools/bootconfig/main.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c
> > index f45fa992e01d..fd67496a947f 100644
> > --- a/tools/bootconfig/main.c
> > +++ b/tools/bootconfig/main.c
> > @@ -111,9 +111,11 @@ static void xbc_show_list(void)
> >  	char key[XBC_KEYLEN_MAX];
> >  	struct xbc_node *leaf;
> >  	const char *val;
> > +	int ret;
> >  
> >  	xbc_for_each_key_value(leaf, val) {
> > -		if (xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX) < 0) {
> > +		ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX);
> > +		if (ret < 0) {
> >  			fprintf(stderr, "Failed to compose key %d\n", ret);
> >  			break;
> >  		}
> > -- 
> > 2.31.1
> > 
> 
> 
> -- 
> Masami Hiramatsu <mhiramat@xxxxxxxxxx>


-- 
Masami Hiramatsu <mhiramat@xxxxxxxxxx>