Skimming open(2), I was surprised not to see tmpfs mentioned as a
filesystem supported by O_TMPFILE.
If I'm understanding correctly (I'm very possibly not!), tmpfs is
a filesystem built on shmem, so I think it's more correct (and
probably much more widely understandable) to refer to tmpfs here.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
There are many slightly different prototypes for this syscall,
but none of them is like the documented one.
Of all the different prototypes,
let's document the asm-generic one.
This manual page was actually using a prototype similar to
mmap(2), but there's no glibc wrapper function called mmap2(2),
as the wrapper for this syscall is mmap(2). Therefore, the
documented prototype should be the kernel one.
......
.../linux$ grep_syscall mmap2
arch/csky/kernel/syscall.c:17:
SYSCALL_DEFINE6(mmap2,
unsigned long, addr,
unsigned long, len,
unsigned long, prot,
unsigned long, flags,
unsigned long, fd,
off_t, offset)
arch/microblaze/kernel/sys_microblaze.c:46:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags, unsigned long, fd,
unsigned long, pgoff)
arch/nds32/kernel/sys_nds32.c:12:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags,
unsigned long, fd, unsigned long, pgoff)
arch/powerpc/kernel/syscalls.c:60:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
unsigned long, prot, unsigned long, flags,
unsigned long, fd, unsigned long, pgoff)
arch/riscv/kernel/sys_riscv.c:37:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags,
unsigned long, fd, off_t, offset)
arch/s390/kernel/sys_s390.c:49:
SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
arch/sparc/kernel/sys_sparc_32.c:101:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags, unsigned long, fd,
unsigned long, pgoff)
arch/ia64/include/asm/unistd.h:30:
asmlinkage unsigned long sys_mmap2(
unsigned long addr, unsigned long len,
int prot, int flags,
int fd, long pgoff);
arch/ia64/kernel/sys_ia64.c:139:
asmlinkage unsigned long
sys_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, long pgoff)
arch/m68k/kernel/sys_m68k.c:40:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags,
unsigned long fd, unsigned long pgoff)
arch/parisc/kernel/sys_parisc.c:275:
asmlinkage unsigned long sys_mmap2(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags, unsigned long fd,
unsigned long pgoff)
arch/powerpc/include/asm/syscalls.h:15:
asmlinkage long sys_mmap2(unsigned long addr, size_t len,
unsigned long prot, unsigned long flags,
unsigned long fd, unsigned long pgoff);
arch/sh/include/asm/syscalls.h:8:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags,
unsigned long fd, unsigned long pgoff);
arch/sh/kernel/sys_sh.c:41:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags,
unsigned long fd, unsigned long pgoff)
arch/sparc/kernel/systbls.h:23:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags,
unsigned long fd, unsigned long pgoff);
include/asm-generic/syscalls.h:14:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags,
unsigned long fd, unsigned long pgoff);
.../linux$
function grep_syscall()
{
if ! [ -v 1 ]; then
>&2 echo "Usage: ${FUNCNAME[0]} <syscall>";
return ${EX_USAGE};
fi
find * -type f \
|grep '\.c$' \
|sort -V \
|xargs pcregrep -Mn "(?s)^\w*SYSCALL_DEFINE.\(${1},.*?\)" \
|sed -E 's/^[^:]+:[0-9]+:/&\n/';
find * -type f \
|grep '\.[ch]$' \
|sort -V \
|xargs pcregrep -Mn "(?s)^asmlinkage\s+[\w\s]+\**sys_${1}\s*\(.*?\)" \
|sed -E 's/^[^:]+:[0-9]+:/&\n/';
}
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The documented prototype for mlock2() was a mix of the
glibc wrapper prototype and the kernel syscall prototype.
Let's document the glibc wrapper prototype, which is shown below.
......
.../glibc$ grep_glibc_prototype mlock2
sysdeps/unix/sysv/linux/bits/mman-shared.h:55:
int mlock2 (const void *__addr, size_t __length, unsigned int __flags) __THROW;
.../glibc$
function grep_glibc_prototype()
{
if ! [ -v 1 ]; then
>&2 echo "Usage: ${FUNCNAME[0]} <func>";
return ${EX_USAGE};
fi
find * -type f \
|grep '\.h$' \
|sort -V \
|xargs pcregrep -Mn \
"(?s)^[^\s#][\w\s]+\s+\**${1}\s*\([\w\s()[\]*,]*?(...)?\)[\w\s()]*;" \
|sed -E 's/^[^:]+:[0-9]+:/&\n/';
}
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
There seems to be no reason <unistd.h> is shown here, so remove it.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
These pages have the odd wording 'the external variable errno',
which does not occur in other pages. Make these pages conform with
the norm.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
fileno(3) differs from the other functions in various ways.
For example, it is governed by different standards,
and can set 'errno'. Conversely, the other functions
are about examining the status of a stream, while
fileno(3) simply obtains the underlying file descriptor.
Furthermore, splitting this function out allows
for some cleaner upcoming changes in ferror(3).
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Calling ipc() directly would be a rather unusual thing to do,
so add some text to emphasize that point.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
I filed a bug against glibc
requesting the wrapper for the new syscall.
Glibc bug: <https://sourceware.org/bugzilla/show_bug.cgi?id=27359>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The 'advice' subsection fell in the middle of other text in the
DESCRIPTION, which is a little confusing. Instead, move that
subsection to the end of the DESCRIPTION, and make some other
minor text reorganization so that related details are placed in
the same paragraphs.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
'malloc_trim' was and is never called from the 'free' function.
see related bug in glibc tracker:
https://sourceware.org/bugzilla/show_bug.cgi?id=2531. or
'__int_free' function. Only the top part of the heap is trimmed
after some calls to 'free', which is different from 'malloc_trim'
which also releases memory in between chunks from all the
arenas/heaps.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Move the the text describing how to set environment variable before
the list(s) of variables in order to improve readability.
[mtk: rewrote commit message]
Signed-off-by: Bastien Roucariès <rouca@debian.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Clearly document that HOME, LOGNAME, SHELL and USER are set at
login time by a program like such as login(1).
Document also that using su could result in a mixed environment,
and point to the su(1) manual page.
[mtk: edited commit message]
Signed-off-by: Bastien Roucariès <rouca@debian.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Add more details of how PATH is used, and mention the legacy
use of an empty prefix.
Changed after a suggested patch by Bastien Roucariès.
Reported-by: Bastien Roucariès <rouca@debian.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Unlike SIOCGIFADDR and SIOCSIFADDR which are supported by many
protocol families, SIOCDIFADDR is supported by AF_INET6 and
AF_APPLETALK only.
Unlike other protocols, AF_INET6 uses struct in6_ifreq.
Cc: Dmitry V. Levin <ldv@altlinux.org>
Cc: <netdev@vger.kernel.org>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk