From: David Laight <David.Laight@ACULAB.COM>
To: 'Willy Tarreau' <w@1wt.eu>, "Paul E . McKenney" <paulmck@kernel.org>
Cc: Mark Brown <broonie@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 11/42] tools/nolibc/types: move the FD_* functions to macros in types.h
Date: Mon, 7 Feb 2022 17:05:21 +0000 [thread overview]
Message-ID: <083fac943c8c422a9f667f6b0371153c@AcuMS.aculab.com> (raw)
In-Reply-To: <20220207162354.14293-12-w@1wt.eu>
From: Willy Tarreau
> Sent: 07 February 2022 16:23
>
> FD_SET, FD_CLR, FD_ISSET, FD_ZERO are supposed to be macros and not
> functions.
Are you sure?
I'd have thought they could be either.
There are certainly systems where they are functions.
They can be implemented as an array of fd numbers rather than a bitmap.
> In addition we already have a file dedicated to such macros
> and types used by syscalls, it's types.h, so let's move them
> there and turn them to macros. FD_CLR() and FD_ISSET() were missing,
> so they were added. FD_ZERO() now deals with its own loop so that it
> doesn't rely on memset() that sets one byte at a time.
>
....
> +#define FD_CLR(fd, set) do { \
> + int __fd = (int)(fd); \
> + fd_set *__set = (fd_set *)(set); \
I'm not sure you really want either cast.
They are just likely to hide some horrid bugs.
+ if (__fd >= 0 && __fd < FD_SETSIZE) \
+ __set->fd32[__fd / 32] &= ~(1U << (__fd & 31)); \
+ } while (0)
+
Do you need the range check?
I don't think glibc has one.
Things just break in obscure ways when you use select on big fd.
David
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Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2022-02-07 17:11 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-07 16:23 [PATCH 00/42] nolibc: update to resync with out-of-tree project Willy Tarreau
2022-02-07 16:23 ` [PATCH 01/42] tools/nolibc: use pselect6 on RISCV Willy Tarreau
2022-02-07 16:23 ` [PATCH 02/42] tools/nolibc: guard the main file against multiple inclusion Willy Tarreau
2022-02-07 16:23 ` [PATCH 03/42] tools/nolibc/std: move the standard type definitions to std.h Willy Tarreau
2022-02-07 16:23 ` [PATCH 04/42] tools/nolibc/types: split syscall-specific definitions into their own files Willy Tarreau
2022-02-07 16:23 ` [PATCH 05/42] tools/nolibc/arch: split arch-specific code into individual files Willy Tarreau
2022-02-07 16:23 ` [PATCH 06/42] tools/nolibc/sys: split the syscall definitions into their own file Willy Tarreau
2022-02-07 16:23 ` [PATCH 07/42] tools/nolibc/stdlib: extract the stdlib-specific functions to " Willy Tarreau
2022-02-07 16:23 ` [PATCH 08/42] tools/nolibc/string: split the string functions into string.h Willy Tarreau
2022-02-07 16:23 ` [PATCH 09/42] tools/nolibc/ctype: split the is* functions to ctype.h Willy Tarreau
2022-02-07 16:23 ` [PATCH 10/42] tools/nolibc/ctype: add the missing is* functions Willy Tarreau
2022-02-07 16:23 ` [PATCH 11/42] tools/nolibc/types: move the FD_* functions to macros in types.h Willy Tarreau
2022-02-07 17:05 ` David Laight [this message]
2022-02-08 5:14 ` Willy Tarreau
2022-02-13 8:52 ` [PATCH v2 " Willy Tarreau
2022-02-07 16:23 ` [PATCH 12/42] tools/nolibc/types: make FD_SETSIZE configurable Willy Tarreau
2022-02-13 8:53 ` [PATCH v2 " Willy Tarreau
2022-02-14 20:17 ` Paul E. McKenney
2022-02-07 16:23 ` [PATCH 13/42] tools/nolibc/types: move makedev to types.h and make it a macro Willy Tarreau
2022-02-07 16:23 ` [PATCH 14/42] tools/nolibc/stdlib: move ltoa() to stdlib.h Willy Tarreau
2022-02-07 16:23 ` [PATCH 15/42] tools/nolibc/stdlib: replace the ltoa() function with more efficient ones Willy Tarreau
2022-02-07 16:23 ` [PATCH 16/42] tools/nolibc/stdlib: add i64toa() and u64toa() Willy Tarreau
2022-02-07 16:23 ` [PATCH 17/42] tools/nolibc/stdlib: add utoh() and u64toh() Willy Tarreau
2022-02-07 16:23 ` [PATCH 18/42] tools/nolibc/stdio: add a minimal set of stdio functions Willy Tarreau
2022-02-07 16:23 ` [PATCH 19/42] tools/nolibc/stdio: add stdin/stdout/stderr and fget*/fput* functions Willy Tarreau
2022-02-07 16:23 ` [PATCH 20/42] tools/nolibc/stdio: add fwrite() to stdio Willy Tarreau
2022-02-07 16:23 ` [PATCH 21/42] tools/nolibc/stdio: add a minimal [vf]printf() implementation Willy Tarreau
2022-02-07 16:23 ` [PATCH 22/42] tools/nolibc/types: define EXIT_SUCCESS and EXIT_FAILURE Willy Tarreau
2022-02-07 16:23 ` [PATCH 23/42] tools/nolibc/stdio: add perror() to report the errno value Willy Tarreau
2022-02-07 16:23 ` [PATCH 24/42] tools/nolibc/sys: make open() take a vararg on the 3rd argument Willy Tarreau
2022-02-07 16:23 ` [PATCH 25/42] tools/nolibc/stdlib: avoid a 64-bit shift in u64toh_r() Willy Tarreau
2022-02-07 16:23 ` [PATCH 26/42] tools/nolibc/stdlib: make raise() use the lower level syscalls only Willy Tarreau
2022-02-07 16:23 ` [PATCH 27/42] tools/nolibc/sys: make getpgrp(), getpid(), gettid() not set errno Willy Tarreau
2022-02-07 16:23 ` [PATCH 28/42] tools/nolibc/string: use unidirectional variants for memcpy() Willy Tarreau
2022-02-07 16:23 ` [PATCH 29/42] tools/nolibc/string: slightly simplify memmove() Willy Tarreau
2022-02-07 16:23 ` [PATCH 30/42] tools/nolibc/string: add strncpy() and strlcpy() Willy Tarreau
2022-02-07 16:23 ` [PATCH 31/42] tools/nolibc/string: add tiny versions of strncat() and strlcat() Willy Tarreau
2022-02-07 16:23 ` [PATCH 32/42] tools/nolibc: move exported functions to their own section Willy Tarreau
2022-02-07 16:23 ` [PATCH 33/42] tools/nolibc/arch: mark the _start symbol as weak Willy Tarreau
2022-02-07 16:23 ` [PATCH 34/42] tools/nolibc/types: define PATH_MAX and MAXPATHLEN Willy Tarreau
2022-02-07 16:23 ` [PATCH 35/42] tools/nolibc/string: export memset() and memmove() Willy Tarreau
2022-02-07 16:23 ` [PATCH 36/42] tools/nolibc/errno: extract errno.h from sys.h Willy Tarreau
2022-02-07 16:23 ` [PATCH 37/42] tools/nolibc/unistd: extract msleep(), sleep(), tcsetpgrp() to unistd.h Willy Tarreau
2022-02-07 16:23 ` [PATCH 38/42] tools/nolibc/unistd: add usleep() Willy Tarreau
2022-02-07 16:23 ` [PATCH 39/42] tools/nolibc/signal: move raise() to signal.h Willy Tarreau
2022-02-07 16:23 ` [PATCH 40/42] tools/nolibc/time: create time.h with time() Willy Tarreau
2022-02-07 16:23 ` [PATCH 41/42] tools/nolibc: also mention how to build by just setting the include path Willy Tarreau
2022-02-07 16:23 ` [PATCH 42/42] tools/nolibc/stdlib: implement abort() Willy Tarreau
2022-02-08 0:00 ` [PATCH 00/42] nolibc: update to resync with out-of-tree project Paul E. McKenney
2022-02-08 4:41 ` Willy Tarreau
2022-02-08 5:10 ` Paul E. McKenney
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