[5.1.x] kconfig: Clear "written" flag to avoid data loss

Message ID 20190805053513.29629-1-yamada.masahiro@socionext.com
State New
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  • [5.1.x] kconfig: Clear "written" flag to avoid data loss
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Commit Message

Masahiro Yamada Aug. 5, 2019, 5:35 a.m.
From: "M. Vefa Bicakci" <m.v.b@runbox.com>


commit 0c5b6c28ed68becb692b43eae5e44d5aa7e160ce upstream.

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@vger.kernel.org> # 4.19+
Signed-off-by: M. Vefa Bicakci <m.v.b@runbox.com>

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

---
 scripts/kconfig/confdata.c | 4 ++++
 1 file changed, 4 insertions(+)

-- 
2.17.1

Comments

Greg Kroah-Hartman Aug. 5, 2019, 5:44 a.m. | #1
On Mon, Aug 05, 2019 at 02:35:13PM +0900, Masahiro Yamada wrote:
> From: "M. Vefa Bicakci" <m.v.b@runbox.com>

> 

> commit 0c5b6c28ed68becb692b43eae5e44d5aa7e160ce upstream.

> 

> 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@vger.kernel.org> # 4.19+

> Signed-off-by: M. Vefa Bicakci <m.v.b@runbox.com>

> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

> ---

>  scripts/kconfig/confdata.c | 4 ++++

>  1 file changed, 4 insertions(+)


5.1.y is end-of-life, so no need for this backport.

thanks,

greg k-h

Patch

diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index fd99ae90a618..0dde19cf7486 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -784,6 +784,7 @@  int conf_write(const char *name)
 	const char *str;
 	char dirname[PATH_MAX+1], tmpname[PATH_MAX+22], newname[PATH_MAX+8];
 	char *env;
+	int i;
 
 	dirname[0] = 0;
 	if (name && name[0]) {
@@ -860,6 +861,9 @@  int conf_write(const char *name)
 	}
 	fclose(out);
 
+	for_all_symbols(i, sym)
+		sym->flags &= ~SYMBOL_WRITTEN;
+
 	if (*tmpname) {
 		strcat(dirname, basename);
 		strcat(dirname, ".old");