* [PATCH] powerpc32: fix warning from include/asm-generic/termios-base.h
@ 2014-12-05 11:20 Christophe Leroy
2015-03-21 0:01 ` Scott Wood
0 siblings, 1 reply; 2+ messages in thread
From: Christophe Leroy @ 2014-12-05 11:20 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
scottwood
Cc: linuxppc-dev, linux-kernel
When size is equal to 1, the test is always true so lets eliminate both 0 and 1
at first.
include/asm-generic/termios-base.h: In function 'user_termio_to_kernel_termios':
include/asm-generic/termios-base.h:35:2: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
if (get_user(termios->c_line, &termio->c_line) < 0)
^
include/asm-generic/termios-base.h: In function 'kernel_termios_to_user_termio':
include/asm-generic/termios-base.h:57:6: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
put_user(termios->c_line, &termio->c_line) < 0 ||
^
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/include/asm/uaccess.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 9485b43..f3028d2 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -54,7 +54,7 @@
#define __access_ok(addr, size, segment) \
(((addr) <= (segment).seg) && \
- (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr)))))
+ (((size) <= 1) || (((size) - 1) <= ((segment).seg - (addr)))))
#endif
--
2.1.0
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: powerpc32: fix warning from include/asm-generic/termios-base.h
2014-12-05 11:20 [PATCH] powerpc32: fix warning from include/asm-generic/termios-base.h Christophe Leroy
@ 2015-03-21 0:01 ` Scott Wood
0 siblings, 0 replies; 2+ messages in thread
From: Scott Wood @ 2015-03-21 0:01 UTC (permalink / raw)
To: LEROY Christophe; +Cc: Paul Mackerras, linuxppc-dev, linux-kernel
On Fri, Dec 05, 2014 at 12:20:25PM +0100, LEROY Christophe wrote:
> When size is equal to 1, the test is always true so lets eliminate both 0 and 1
> at first.
>
> include/asm-generic/termios-base.h: In function 'user_termio_to_kernel_termios':
> include/asm-generic/termios-base.h:35:2: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
> if (get_user(termios->c_line, &termio->c_line) < 0)
> ^
> include/asm-generic/termios-base.h: In function 'kernel_termios_to_user_termio':
> include/asm-generic/termios-base.h:57:6: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
> put_user(termios->c_line, &termio->c_line) < 0 ||
> ^
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> ---
> arch/powerpc/include/asm/uaccess.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
> index 9485b43..f3028d2 100644
> --- a/arch/powerpc/include/asm/uaccess.h
> +++ b/arch/powerpc/include/asm/uaccess.h
> @@ -54,7 +54,7 @@
>
> #define __access_ok(addr, size, segment) \
> (((addr) <= (segment).seg) && \
> - (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr)))))
> + (((size) <= 1) || (((size) - 1) <= ((segment).seg - (addr)))))
Again, I don't think Linux enables this warning. What did you do to
produce this? In any case, it's a bad warning that doesn't take macros
into account, and the answer is not to make the code less clear by hiding
the fact that zero is a special case.
-Scott
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2015-03-21 0:01 ` Scott Wood
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