netdev - [PATCH v2 06/16] ide: Remove uninitialized

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Date:   Fri, 19 Jun 2020 20:29:57 -0700
From:   Kees Cook <keescook@...omium.org>
To:     linux-kernel@...r.kernel.org
Cc:     Kees Cook <keescook@...omium.org>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Miguel Ojeda <miguel.ojeda.sandonis@...il.com>,
        Alexander Potapenko <glider@...gle.com>,
        Joe Perches <joe@...ches.com>,
        Andy Whitcroft <apw@...onical.com>, x86@...nel.org,
        drbd-dev@...ts.linbit.com, linux-block@...r.kernel.org,
        b43-dev@...ts.infradead.org, netdev@...r.kernel.org,
        linux-doc@...r.kernel.org, linux-wireless@...r.kernel.org,
        linux-ide@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-spi@...r.kernel.org, linux-mm@...ck.org,
        clang-built-linux@...glegroups.com
Subject: [PATCH v2 06/16] ide: Remove uninitialized_var() usage

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings (e.g.
"unused variable"). If the compiler thinks it is uninitialized, either
simply initialize the variable or make compiler changes. As a precursor
to removing[2] this[3] macro[4], just remove this variable since it was
actually unused:

drivers/ide/ide-taskfile.c:232:34: warning: unused variable 'flags' [-Wunused-variable]
        unsigned long uninitialized_var(flags);
                                        ^

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Fixes: ce1e518190ea ("ide: don't disable interrupts during kmap_atomic()")
Reviewed-by: Nick Desaulniers <ndesaulniers@...gle.com>
Signed-off-by: Kees Cook <keescook@...omium.org>
---
 drivers/ide/ide-taskfile.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index aab6a10435b6..a26f85ab58a9 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -229,7 +229,6 @@ void ide_pio_bytes(ide_drive_t *drive, struct ide_cmd *cmd,
 	ide_hwif_t *hwif = drive->hwif;
 	struct scatterlist *sg = hwif->sg_table;
 	struct scatterlist *cursg = cmd->cursg;
-	unsigned long uninitialized_var(flags);
 	struct page *page;
 	unsigned int offset;
 	u8 *buf;
-- 
2.25.1