From: Masahiro Yamada <masahi...@kernel.org> This is a cherry-pick from the kernel commit: 6262afa10ef7c (kconfig: default to zero if int/hex symbol lacks default property, 2023-11-26)
When a default property is missing in an int or hex symbol, it defaults to an empty string, which is not a valid symbol value. It results in an incorrect .config, and can also lead to an infinite loop in scripting. Use "0" for int and "0x0" for hex as a default value. Signed-off-by: Masahiro Yamada <masahi...@kernel.org> Reviewed-by: Yoann Congal <yoann.con...@smile.fr> Signed-off-by: Yoann Congal <yoann.con...@smile.fr> --- Added context that was not in the upstream commit: The infinite loop case happens with a configuration defined like this (a hex config without a valid default value): config HEX_TEST hex "Hex config without default" And using: $ make oldconfig < /dev/null scripts/kconfig/conf --oldconfig Kconfig * * General setup * Error in reading or end of file. Error in reading or end of file. Hex config without default (HEX_TEST) [] (NEW) Error in reading or end of file. Hex config without default (HEX_TEST) [] (NEW) # This loops forever NB: Scripted config manipulation often call make with /dev/null as stdin (Yocto recipe, CI build, ...) This was discovered when working on Yocto bug: https://bugzilla.yoctoproject.org/show_bug.cgi?id=14136 --- scripts/kconfig/symbol.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c index 703b9b899ee..b4c51de3f20 100644 --- a/scripts/kconfig/symbol.c +++ b/scripts/kconfig/symbol.c @@ -343,7 +343,11 @@ void sym_calc_value(struct symbol *sym) switch (sym->type) { case S_INT: + newval.val = "0"; + break; case S_HEX: + newval.val = "0x0"; + break; case S_STRING: newval = symbol_empty.curr; break; @@ -753,15 +757,17 @@ const char *sym_get_string_default(struct symbol *sym) case yes: return "y"; } case S_INT: + if (!str[0]) + str = "0"; + break; case S_HEX: - return str; - case S_STRING: - return str; - case S_OTHER: - case S_UNKNOWN: + if (!str[0]) + str = "0x0"; + break; + default: break; } - return ""; + return str; } const char *sym_get_string_value(struct symbol *sym) -- 2.39.2