The terms POSIX.1-{2003,2004,2013,2016} were inventions of
my imagination, as confirmed by consulting Geoff Clare of
The Open Group. Remove these names.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Avoid implying that use of IFUNC is the only way to produce a
symbol with NULL value. Give more scenarios how a symbol may get
NULL value, but explain that in those scenarios dlsym() will fail
with Glibc's ld.so due to an implementation inconsistency.
Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
iproute2 allows you to specify the netns for either side of a veth
interface at creation time. Add an example of this to veth(4) so
it doesn't sound like you have to move the interfaces in a
separate step.
Verified with commands:
# ip netns add alpha
# ip netns add bravo
# ip link add foo netns alpha type veth peer bar netns bravo
# ip -n alpha link show
# ip -n bravo link show
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Adding description of new directories (/run, /usr/libexec,
/usr/share/color,/usr/share/ppd, /var/lib/color), stating
/usr/X11R6 as removed and updating URL to and version of FHS.
See https://bugzilla.kernel.org/show_bug.cgi?id=206693
Reported-by: Gary Perkins <glperkins@lit.edu>
Signed-off-by: Thomas Piekarski <t.piekarski@deloquencia.de>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
As noted in email by Christian Brauner:
I forgot to mention that spawning directly into a target
cgroup is also more efficient than moving it after creation.
The specific reason is mentioned in the commit message
[ef2c41cf38a], the write lock of the semaphore need not be
taken in contrast to when it is moved afterwards. That
implementation details is not that interesting but it might
be interesting to know that it provides performance benefits
in general.
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This is a sequel to commit baf17bc4f2, addressing the
issues with missing commas in the middle of SEE ALSO lists that
emerged since.
The awk script from the original commit was not working and had to
be slightly modified (s/["]SEE ALSO["]/"?SEE ALSO/), otherwise it
works like a charm. Here's the fixed script and its output just
before this commit:
for f in man*/*; do
awk '
/^.SH "?SEE ALSO/ {
sa=1; print "== " FILENAME " =="; print; next
}
/^\.(PP|SH)/ {
sa=0; no=0; next
}
/^\.BR/ {
if (sa==1) {
print;
if (no == 1)
print "Missing comma in " FILENAME " +" FNR-1; no=0
}
}
/^\.BR .*)$/ {
if (sa==1)
no=1;
next
}
/\.\\"/ {next}
/.*/ {
if (sa==1) {
print; next
}
}
' $f; done | grep Missing
Missing comma in man1/memusage.1 +272
Missing comma in man2/adjtimex.2 +597
Missing comma in man2/adjtimex.2 +598
Missing comma in man2/mkdir.2 +252
Missing comma in man2/sigaction.2 +1045
Missing comma in man2/sigaction.2 +1047
Missing comma in man3/mbsnrtowcs.3 +198
Missing comma in man3/ntp_gettime.3 +142
Missing comma in man3/strcmp.3 +219
Missing comma in man3/strtol.3 +302
Missing comma in man3/wcstombs.3 +120
Missing comma in man7/user_namespaces.7 +1378
Missing comma in man7/xattr.7 +198
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
prctls that are architecture-specific won't work on other
architectures, and arch-specific prctls that manipulate optional
hardware features likewise won't work if that hardware feature is
not present.
The established pattern seems to be to treat such prctls as if they
are unimplemented, when attempted on the wrong hardware.
Cover these cases with some generic weasel words in the closet
existing EINVAL clause.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Fix a few very minor bits of punctuation in
PR_SET_SPECULATION_CTRL and PR_GET_SPECULATION_CTRL.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The description of PR_SET_PDEATHSIG refers to "maxsig", which
is apparently intended to stand for the maximum defined signal
number.
maxsig seems not to be a thing, even in the kernel.
Reword to use the standard constant NSIG. (Discussion of SIGRTMIN
and SIGRTMAX seems out of scope here, and anyway is not relevant
to the kernel.)
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The Intel MPX API was removed from Linux 5.4. See Linux
commit f240652b6032 ("x86/mpx: Remove MPX APIs")
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The prctl list has historically been sorted by prctl name (ignoring
any SET_ or GET_ prefix) to make individual prctls easier to find.
Some noise seems to have crept in since.
Sort the list back into order. Similarly, reorder the list of
prctls specified to return non-zero values on success.
Content movement only. No semantic change.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The prctl.2 source is unnecessarily hard to navigate, not least
because prctl option flags are traditionally named PR_* and so look
just like prctl names.
For each actual prctl, add a comment of the form
.\" prctl PR_FOO
to make it move obvious where each top-level prctl starts.
Of course, we could add some clever macros, but let's not confuse
dumb parsers.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
In reality, almost every prctl interferes with assumptions that the
compiler and C library / runtime rely on. prctl() can therefore
make userspace explode in a variety ways that are likely to be hard
to debug.
This is not obvious to the uninitiated, so add a warning.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Under PR_SET_NAME, the [tid] value seen in procfs as
/proc/self/task/[tid] is mistakenly described as the name of the
thread, whereas really the name is on /proc/self/task/[tid]/comm.
Fix it.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The current synopsis for prctl(2) misleadingly claims that prctl
operates on a process. Rather, some (in fact, most) prctls operate
on a thread.
The wording probably dates back to the old days when Linux didn't
really have threads at all.
Reword as appropriate.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
No content changes. Just put things in a slightly more logical
order and add a few paragraph breaks for readability.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk