Glibc doesn't (and quite probably won't) include a wrapper for this
system call. Therefore, point out that potential callers will need
to use syscall(2), and rewrite the RETURN VALUE text to show things
as they would be if syscall() is used.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Add a para to start of page that points out that this is the
low-level, Linux-specific API, and point the reader to posix_fallocate(3)
for the portable API.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Most of the relevant discussion is now under /proc/PID/mounts;
all that needs to be here is a mention of the pre-2.4.19
system-wide namespace situation, and a reference to the
discussion under /proc/PID/mounts.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Describe per-process namespaces, including discussion
of clone() and unshare CLONE_NEWNS, and /proc/PID/mounts.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The length of this page means that it's becoming difficult to parse
which info is specific to mount() versus umount()/umount2(), so split
the umount material out into its own page.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Refer the reader to new text in execve(2) that describes how
(since Linux 2.6.23) RLIMIT_STACK determines the value of ARG_MAX.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
POSIX.1-2001 says that the values returned by sysconf()
are constant for the life of the process.
But the fact that, since Linux 2.6.23, ARG_MAX is settable
via RLIMIT_STACK means _SC_ARG_MAX is no longer constant,
since it can change at each execve().
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Starting with Linux 2.6.23, the ARG_MAX limit became settable via
(1/4 of) RLIMIT_STACK. This broke ABI compatibility if RLIMIT_STACK
was set such that ARG_MAX was < 32 pages. Document the fact that
since 2.6.25 Linux imposes a floor on ARG_MAX, so that the old limit
of 32 pages is guaranteed.
For some background on the changes to ARG_MAX in kernels 2.6.23 and
2.6.25, see:
http://sourceware.org/bugzilla/show_bug.cgi?id=5786http://bugzilla.kernel.org/show_bug.cgi?id=10095http://thread.gmane.org/gmane.linux.kernel/646709/focus=648101,
checked into 2.6.25 as commit a64e715fc74b1a7dcc5944f848acc38b2c4d4ee2.
Also some reordering/rewording of the discussion of ARG_MAX.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The old sentence sat on its own in an odd place, and anyway the
modern BSDs use the name RLIMIT_NOFILE.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Include text describing semantics of fork() and execve() for
signal dispositions, signal mask, and pending signal set.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
A sentence clarifying that pending signal set is union of
per-thread and process-wide pending signal sets.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk