| Message ID | 20200615085132.166470-1-yanaijie@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | f2fs: Eliminate usage of uninitialized_var() macro | expand |
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 <keescook@chromium.org> > Suggested-by: Chao Yu <yuchao0@huawei.com> > Signed-off-by: Jason Yan <yanaijie@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> 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 <keescook@chromium.org> > Suggested-by: Chao Yu <yuchao0@huawei.com> > Signed-off-by: Jason Yan <yanaijie@huawei.com> > --- > v2: Directly remove this variable. Thanks! I've applied this to my uninitialized_var() macro removal series.
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;
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 <keescook@chromium.org> Suggested-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jason Yan <yanaijie@huawei.com> --- v2: Directly remove this variable. fs/f2fs/data.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)