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* [PATCH] f2fs: Eliminate usage of uninitialized_var() macro
@ 2020-06-15  4:02 Jason Yan
  2020-06-15  8:26 ` [f2fs-dev] " Chao Yu
  0 siblings, 1 reply; 3+ messages in thread
From: Jason Yan @ 2020-06-15  4:02 UTC (permalink / raw)
  To: jaegeuk, chao, linux-f2fs-devel, linux-kernel
  Cc: kernel-hardening, Jason Yan, Kees Cook

This is an effort to eliminate the uninitialized_var() macro[1].

The use of this macro is the wrong solution because it forces off ANY
analysis by the compiler for a given variable. It even masks "unused
variable" warnings.

Quoted from Linus[2]:

"It's a horrible thing to use, in that it adds extra cruft to the
source code, and then shuts up a compiler warning (even the _reliable_
warnings from gcc)."

The gcc option "-Wmaybe-uninitialized" has been disabled and this change
will not produce any warnnings even with "make W=1".


Cc: Kees Cook <>
Signed-off-by: Jason Yan <>
 fs/f2fs/data.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 326c63879ddc..e6ec61274d76 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2856,7 +2856,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
 	int nr_pages;
-	pgoff_t uninitialized_var(writeback_index);
+	pgoff_t writeback_index;
 	pgoff_t index;
 	pgoff_t end;		/* Inclusive */
 	pgoff_t done_index;

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2020-06-15  8:38 UTC | newest]

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2020-06-15  4:02 [PATCH] f2fs: Eliminate usage of uninitialized_var() macro Jason Yan
2020-06-15  8:26 ` [f2fs-dev] " Chao Yu
2020-06-15  8:38   ` Jason Yan

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