Prior to this commit, starting nconfig, xconfig or gconfig, and saving the .config file more than once caused data loss, where a .config file that contained only comments would be written to disk starting from the second save operation. This bug manifests itself because the SYMBOL_WRITTEN flag is never cleared after the first call to conf_write, and subsequent calls to conf_write then skip all of the configuration symbols due to the SYMBOL_WRITTEN flag being set. This commit resolves this issue by clearing the SYMBOL_WRITTEN flag from all symbols before conf_write returns. Fixes: 8e2442a5f86e ("kconfig: fix missing choice values in auto.conf") Cc: linux-stable <stable@xxxxxxxxxxxxxxx> # 4.19+ Signed-off-by: M. Vefa Bicakci <m.v.b@xxxxxxxxxx> --- Changes since v1: * As suggested by Masahiro Yamada, instead of defining a new helper function to traverse over all symbols in a pre-defined order, use the for_all_symbols iterator. --- scripts/kconfig/confdata.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c index 1134892599da..3569d2dec37c 100644 --- a/scripts/kconfig/confdata.c +++ b/scripts/kconfig/confdata.c @@ -848,6 +848,7 @@ int conf_write(const char *name) const char *str; char tmpname[PATH_MAX + 1], oldname[PATH_MAX + 1]; char *env; + int i; bool need_newline = false; if (!name) @@ -930,6 +931,9 @@ int conf_write(const char *name) } fclose(out); + for_all_symbols(i, sym) + sym->flags &= ~SYMBOL_WRITTEN; + if (*tmpname) { if (is_same(name, tmpname)) { conf_message("No change to %s", name); -- 2.21.0