Exit on error when asking for value and reading stdin returns an error
(mainly if it has reached EOF or is closed).
This infinite loop happens in particular for hex/int configs without an
explicit default value.
Previously, this case would loop:
* oldconfig prompts for the value but stdin has reached EOF
* It gets the global default value : an empty string
* This is not a valid hex/int value so it prompts again, hence the
infinite loop.
This case happens with a configuration like this (a hex config without a
valid default value):
config TEST_KCONFIG
hex "Test KConfig"
# default 0x0
And using:
make oldconfig < /dev/null
This was discovered when working on Yocto bug[0] on a downstream
kconfig user (U-boot)
[0]: https://bugzilla.yoctoproject.org/show_bug.cgi?id=14136
CC: Brandon Maier <brandon.maier@xxxxxxxxxxx>
Signed-off-by: Yoann Congal <yoann.congal@xxxxxxxx>
---
v4->v5:
* Switched to Masahiro Yamada's suggested code.
v3->v4:
* Added Brandon Maier's "Tested-by". Thanks!
v2->v3:
* Simplify the patch by fusing comments of :
* Masahiro Yamada : Exit as soon as reading stdin hits an error
* Randy Dunlap : Display the name of the currently read symbol
v1->v2:
* Improve coding style
* Put more info in the commit message
---
scripts/kconfig/conf.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c
index 33d19e419908..62de1fbaff97 100644
--- a/scripts/kconfig/conf.c
+++ b/scripts/kconfig/conf.c
@@ -76,8 +76,10 @@ static void strip(char *str)
/* Helper function to facilitate fgets() by Jean Sacren. */
static void xfgets(char *str, int size, FILE *in)
{
- if (!fgets(str, size, in))
+ if (!fgets(str, size, in)) {
fprintf(stderr, "\nError in reading or end of file.\n");
+ exit(1);
+ }
if (!tty_stdio)
printf("%s", str);
--
2.30.2
