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)."
Fix it by remove this variable since it is not needed at all.
[1] https://github.com/KSPP/linux/issues/81
[2] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/
Cc: Kees Cook <[email protected]>
Suggested-by: Chao Yu <[email protected]>
Signed-off-by: Jason Yan <[email protected]>
---
v2: Directly remove this variable.
fs/f2fs/data.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 326c63879ddc..3753ba06531b 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2856,7 +2856,6 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
};
#endif
int nr_pages;
- pgoff_t uninitialized_var(writeback_index);
pgoff_t index;
pgoff_t end; /* Inclusive */
pgoff_t done_index;
@@ -2875,8 +2874,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
clear_inode_flag(mapping->host, FI_HOT_DATA);
if (wbc->range_cyclic) {
- writeback_index = mapping->writeback_index; /* prev offset */
- index = writeback_index;
+ index = mapping->writeback_index; /* prev offset */
end = -1;
} else {
index = wbc->range_start >> PAGE_SHIFT;
--
2.25.4
On 2020/6/15 16:51, Jason Yan wrote:
> 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)."
>
> Fix it by remove this variable since it is not needed at all.
>
> [1] https://github.com/KSPP/linux/issues/81
> [2] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/
>
> Cc: Kees Cook <[email protected]>
> Suggested-by: Chao Yu <[email protected]>
> Signed-off-by: Jason Yan <[email protected]>
Reviewed-by: Chao Yu <[email protected]>
Thanks,
On Mon, Jun 15, 2020 at 04:51:32PM +0800, Jason Yan wrote:
> 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)."
>
> Fix it by remove this variable since it is not needed at all.
>
> [1] https://github.com/KSPP/linux/issues/81
> [2] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/
>
> Cc: Kees Cook <[email protected]>
> Suggested-by: Chao Yu <[email protected]>
> Signed-off-by: Jason Yan <[email protected]>
> ---
> v2: Directly remove this variable.
Thanks! I've applied this to my uninitialized_var() macro removal
series.
--
Kees Cook