Re: [PATCH] posix_types.h: Cleanup stale __NFDBITS and relateddefinitions

From: Ben Hutchings
Date: Wed Jul 25 2012 - 19:26:47 EST


On Wed, 2012-07-25 at 10:40 -0400, Josh Boyer wrote:
> Recently, glibc made a change to suppress sign-conversion warnings in FD_SET
> (glibc commit ceb9e56b3d1). This uncovered an issue with the kernel's
> definition of __NFDBITS if applications #include <linux/types.h> after
> including <sys/select.h>. A build failure would be seen when passing the
> -Werror=sign-compare and -D_FORTIFY_SOURCE=2 flags to gcc.
>
> It was suggested that the kernel should either match the glibc definition of
> __NFDBITS or remove that entirely. The current in-kernel uses of __NFDBITS
> can be replaced with BITS_PER_LONG, and there are no uses of the related
> __FDELT and __FDMASK defines. Given that, we'll continue the cleanup that
> was started with commit 8b3d1cda4f5f ("posix_types: Remove fd_set macros")
> and drop the remaining unused macros.
>
> Additionally, linux/time.h has similar macros defined that expand to nothing
> so we'll remove those at the same time.
>
> Reported-by: Jeff Law <law@xxxxxxxxxx>
> Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> CC: <stable@xxxxxxxxxxxxxxx>

# v3.4+

(as 8b3d1cda4f5f went into 3.4)

> Signed-off-by: Josh Boyer <jwboyer@xxxxxxxxxx>
[...]

--
Ben Hutchings
Humans are not rational beings; they are rationalising beings.

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