close_range() CLOSE_RANGE_USHARE triggers a call to dup_fd()
which in turn calls alloc_fdtable(), which checks that
sysctl_nr_open has not been exceeded.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The current example program can't really be used to demonstrate the
effect of close_range(). Replace it by a program that does show the
effect of this system call.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This documents close_range(2) based on information in
278a5fbaed89dacd04e9d052f4594ffd0e0585de,
60997c3d45d9a67daf01c56d805ae4fec37e0bd8, and
582f1fb6b721facf04848d2ca57f34468da1813e.
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Stephen Kitt <steve@sk2.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The manual pages are already inconsistent in which headers need
to be included. Right now, not all of the types used by a
function have their required header included in the SYNOPSIS.
If we were to add the headers required by all of the types used by
functions, the SYNOPSIS would grow too much. Not only it would
grow too much, but the information there would be less precise.
Having system_data_types(7) document each type with all the
information about required includes is much more precise, and the
info is centralized so that it's much easier to maintain.
So let's document only the include required for the function
prototype, and also the ones required for the macros needed to
call the function.
<sys/types.h> only defines types, not functions or constants, so
it doesn't belong to man[23] (function) pages at all.
I ignore if some old systems had headers that required you to
include <sys/types.h> *before* them (incomplete headers), but if
so, those implementations would be broken, and those headers
should probably provide some kind of warning. I hope this is not
the case.
[mtk: Already in 2001, POSIX.1 removed the requirement to
include <sys/types.h> for many APIs, so this patch seems
well past due.]
Acked-by: Zack Weinberg <zackw@panix.com>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
RESOLVE_CACHED allows an application to attempt a cache-only open
of a file. If this isn't possible, the request will fail with
-1/EAGAIN and the caller should retry without RESOLVE_CACHED set.
This will generally happen from a different context, where a slower
open operation can be performed.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
POSIX specifies that _exit() and _Exit() shall not return.
Glibc uses __attribute__((__noreturn__)).
Let's use standard C11 'noreturn' in the manual page.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use the glibc prototypes instead of the kernel ones.
Exception: use 'int' instead of 'enum'.
......
.../glibc$ grep_glibc_prototype pciconfig_read
sysdeps/unix/sysv/linux/alpha/sys/io.h:72:
extern int pciconfig_read (unsigned long int __bus,
unsigned long int __dfn,
unsigned long int __off,
unsigned long int __len,
unsigned char *__buf) __THROW;
sysdeps/unix/sysv/linux/ia64/sys/io.h:57:
extern int pciconfig_read (unsigned long int __bus, unsigned long int __dfn,
unsigned long int __off, unsigned long int __len,
unsigned char *__buf);
.../glibc$ grep_glibc_prototype pciconfig_write
sysdeps/unix/sysv/linux/alpha/sys/io.h:78:
extern int pciconfig_write (unsigned long int __bus,
unsigned long int __dfn,
unsigned long int __off,
unsigned long int __len,
unsigned char *__buf) __THROW;
sysdeps/unix/sysv/linux/ia64/sys/io.h:61:
extern int pciconfig_write (unsigned long int __bus, unsigned long int __dfn,
unsigned long int __off, unsigned long int __len,
unsigned char *__buf);
.../glibc$ grep_glibc_prototype pciconfig_iobase
sysdeps/unix/sysv/linux/alpha/sys/io.h:66:
extern long pciconfig_iobase(enum __pciconfig_iobase_which __which,
unsigned long int __bus,
unsigned long int __dfn)
__THROW __attribute__ ((const));
.../glibc$
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
All but the last parameters of t[g]kill() use 'pid_t',
both in the kernel and glibc. Fix them.
......
.../linux/linux$ grep_syscall tkill
kernel/signal.c:3870:
SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig)
include/linux/syscalls.h:685:
asmlinkage long sys_tkill(pid_t pid, int sig);
.../linux/linux$
.../gnu/glibc$ grep_glibc_prototype tgkill
sysdeps/unix/sysv/linux/bits/signal_ext.h:29:
extern int tgkill (__pid_t __tgid, __pid_t __tid, int __signal);
.../gnu/glibc$
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The kernel syscall uses 'loff_t', but the glibc wrapper uses 'off64_t'.
Let's document the wrapper prototype, as in other pages.
......
.../glibc$ grep_glibc_prototype splice
sysdeps/unix/sysv/linux/bits/fcntl-linux.h:398:
extern __ssize_t splice (int __fdin, __off64_t *__offin, int __fdout,
__off64_t *__offout, size_t __len,
unsigned int __flags);
.../glibc$
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The type of fsgid is git_t, and not uid_t. Fix it.
......
.../glibc$ grep_glibc_prototype setfsgid
sysdeps/unix/sysv/linux/sys/fsuid.h:31:
extern int setfsgid (__gid_t __gid) __THROW;
.../glibc$
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
"Mibibytes" is a misspelling of "mebibytes",
but let's use more familiar "MiB" instead.
Signed-off-by: Jakub Wilk <jwilk@jwilk.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
I just happened upon this inconsistent text while reading `man 2
execve`. The code in question landed in 2.6.23 as b6a2fea39318
("mm: variable length argument support").
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
POSIX specifies that the parameters of timer_settime()
shall be 'restrict'. Glibc uses 'restrict' too.
Let's use it here too.
......
.../glibc$ grep_glibc_prototype timer_settime
time/time.h:242:
extern int timer_settime (timer_t __timerid, int __flags,
const struct itimerspec *__restrict __value,
struct itimerspec *__restrict __ovalue) __THROW;
.../glibc$
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Glibc uses 'restrict' for the types of the parameters of statx().
Let's use it here too.
......
.../glibc$ grep_glibc_prototype statx
io/bits/statx-generic.h:60:
int statx (int __dirfd, const char *__restrict __path, int __flags,
unsigned int __mask, struct statx *__restrict __buf)
__THROW __nonnull ((2, 5));
.../glibc$
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
POSIX specifies that the parameters of sigaltstack()
shall be 'restrict'. Glibc uses 'restrict' too.
Let's use it here too.
......
.../glibc$ grep_glibc_prototype sigaltstack
signal/signal.h:320:
extern int sigaltstack (const stack_t *__restrict __ss,
stack_t *__restrict __oss) __THROW;
.../glibc$
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
POSIX specifies that the parameters of getsockopt()
shall be 'restrict'. Glibc uses 'restrict' too.
Let's use it here too.
......
.../glibc$ grep_glibc_prototype getsockopt
socket/sys/socket.h:208:
extern int getsockopt (int __fd, int __level, int __optname,
void *__restrict __optval,
socklen_t *__restrict __optlen) __THROW;
.../glibc$
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
POSIX specifies that the parameters of getpeername()
shall be 'restrict'. Glibc uses 'restrict' too.
Let's use it here too.
......
.../glibc$ grep_glibc_prototype getpeername
socket/sys/socket.h:130:
extern int getpeername (int __fd, __SOCKADDR_ARG __addr,
socklen_t *__restrict __len) __THROW;
.../glibc$
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The page used 'hint' and 'advice' synonymously. This leaves the
reader wondering if the terms mean the same thing, or different
things. They mean the same thing, so use just one term.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>