This commit just addresses those warnings shown below.
Reference(s):
proc/sysinfo.c: In function `getrunners':
proc/sysinfo.c:491:26: warning: `%s' directive writing up to 255 bytes into a region of size 26 [-Wformat-overflow=]
491 | sprintf(tbuf, "/proc/%s/stat", ent->d_name);
| ^~
pgrep.c: In function `select_procs':
pgrep.c:591:11: warning: suggest explicit braces to avoid ambiguous `else' [-Wdangling-else]
591 | else if (opt_older)
| ^
Signed-off-by: Jim Warner <james.warner@comcast.net>
There was a "buff[BUFFSIZE-1] = 0;" but there may be garbage between
what is read() (less than BUFFSIZE-1 bytes) and this null byte. Reuse
the construct from the preceding getrunners().
The combined results of merge request #49 without that
overhead plus distortion in this repository's history.
Prototyped-by: Wayne Porter <wporter82@gmail.com>
Fixing invalid reads in find_elf_note due to setenv invocation
Resolves issue on mailing list from 12 Nov 2014 and Red Hat Bugzilla 1163404.
See merge request !20
For a specific slice of kernel versions we can get a better
estimate of the available memory before the "real" available
figure appears around kernel 3.2
However, that middle method requires a /proc/sys/vm directory.
FreeBSD 9.x used to emulate a < 2.6.27 kernel procfs meaning
it never tried the middle method. FreeBSD 10.x emulates something
more modern, but without the available figure and without a
/proc/sys/vm, so the library falls into a hole.
Hurd may to one day have this bug so we'll exclude him as well
as its triggered by whatever number appears in
/proc/sys/kernel/osrelease
References:
commit 3f3b1a59adhttps://bugs.debian.org/831396
Multiple scanf()s use the GNU-permitted %Lu. This is not supported in
other libraries and isn't to the POSIX specification. The L modifier
is only used for floats in POSIX.
Replacing %Lu with %llu is the same for GNU libc (scanf(3) says as much)
but means other libraries will work fine.
Closes: #19
References:
http://pubs.opengroup.org/onlinepubs/009695399/functions/fscanf.html
Added function procps_linux_version() which used to be an
exported integer instead. Also changed the method of obtaining
the linux version (more correctly the os release) to use a specific
procfs entry. This works for both Linux and FreeBSD.
Under a lxc container, the /proc/meminfo 'MemFree' and
'MemAvailable' amounts will be equal, unless memory is
being limited via cgroups in which case 'MemAvailable'
could exceed that for 'MemTotal'. And when a container
has been nested, there exist additional memory quirks.
A program might then display used or available amounts
greater than total memory (assuming unsigned honored),
or negative values (should a signed cast be employed).
This anomaly primarily impacted the top and free pgms.
Thus, two simple sanity checks have been introduced to
avoid any illogical kb_main_available or kb_main_used.
( Busybox top & free also display anomalous although )
( different results when running in a lxc container. )
Reference(s):
https://bugzilla.redhat.com/show_bug.cgi?id=1153817
Signed-off-by: Jim Warner <james.warner@comcast.net>
Let's not report zero for kb_main_available when older
kernels don't have MemAvailable. Instead, if we simply
duplicate the 'free' amount we can avoid all ancillary
problems, such as those involving top's graphing mode.
Reference(s):
http://www.freelists.org/post/procps/kb-main-available-etc,3
Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit just ensures recalculation of some amounts
for iterative processes, like top. It also trades some
repeated runtime calls to sysconf for a one time cost.
Reference(s):
http://www.freelists.org/post/procps/systemd-support-to-library,7
. fall-back calculations
commit b779855cf1
Signed-off-by: Jim Warner <james.warner@comcast.net>
The stderr message regarding ELF notes appears on some
systems (openSUSE-13.1 for example) but I have not yet
isolated why. Since at startup we go on to determine a
Hertz value the old fashion way, this patch just turns
off the useless message until the cause is understood.
Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit adds support for fallback calculation
of the MemAvailable field if not exported by the
kernel. The MemAvailable field appeared in kernel
3.14, but it's possible to calculate it from other
fields since 2.6.27 (splitLRU changes).
This commit adds a new switch -a/--available that
appends a new column called 'available' to the
output. The column displays an estimation
of how much memory is available for starting
new applications, without swapping. Unlike the data
provided by the 'cached' or 'free' fields, this
field takes into account page cache and also that
not all reclaimable memory slabs will be reclaimed
due to items being in use.
The subtraction was marked as reinforcing the misconception,
that memory in the page cache can be considered free.
The Cached value is not a sum of page cache and tmpfs,
as the tmpfs memory lives in the page cache and therefore
it's an inseparable part of it.
tmpfs has become much more widely used since distributions use it for
/tmp (Fedora 18+). In /proc/meminfo, memory used by tmpfs is accounted
into "Cached" (aka "NR_FILE_PAGES",
http://lxr.free-electrons.com/source/mm/shmem.c#L301 ).
The tools just pass it on, so what top, free and vmstat report as
"cached" is the sum of page cache and tmpfs.
free has the extremely useful "-/+ buffers/cache" output. However, now
that tmpfs is accounted into "cached", those numbers are way off once
you have big files in /tmp.
Fortunately, kernel 2.6.32 introduces "Shmem", which makes tmpfs memory
usage accessible from userspace (
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=4b02108ac1b3354a22b0d83c684797692efdc395 ).
This patch substracts Shmem from Cached to get the actual page cache
memory. This makes both issues mentioned above disappear. For older
kernels, Shmem is not available (hence zero) and this patch is no-op.
Additionally:
* Update the man pages of free and vmstat to explain what is happening
* Finally drop "MemShared" from the /proc/meminfo parser, it has been
dead for 10+ years and is only causing confusion ( removed in kernel
2.5.54, see
https://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/?id=fe04e9451e5a159247cf9f03c615a4273ac0c571 )
vmstat -d or vmstat -p would crash mysteriously under different
circumstances. The problem was eventually tracked down to /sys not
being mounted which meant is_disk() always returned false.
The partition would then be attempted to be linked to a non-existent
disk causing a segfault.
vmstat will now not link to a disk if none exists.
The change in testing will skip those tests when /sys/block doesn't
exist.
Many thanks to Daniel Schepler for his analysis and suggestions.
Bug-Debian: http://bugs.debian.org/736628
Previously the shared memory column was always zero
for 2.6 series kernels (and later) due to the fact,
that the value was taken from the MemShared entry
that disappeared with 2.6 series kernels.
Later a new Shmem entry appeared in the /proc/meminfo
file and the 'shared' column now displays either
the MemShared or the Shmem value (depending on their
presence - the presence is mutually exclusive).
If none of the two entries is exported by the kernel,
then the column is zero.
An unpleasant thing happened when I comitted the shmem support
for the 'free' tool. We already had a merge request from
Adrian Brzezinski in the queue, doing exactly the same.
As Adrian deserves credits, I'm reverting the change
and re-applying with the next commit in order to make
him a part of the project history.
Previously the shared memory column was always zero
for 2.6 series kernels (and later) due to the fact,
that the value was taken from the MemShared entry
that disappeared with 2.6 series kernels.
Later a new Shmem entry appeared in the /proc/meminfo
file and the 'shared' column now displays either
the MemShared or the Shmem value (depending on their
presence - the presence is mutually exclusive).
If none of the two entries is exported by the kernel,
then the column is zero.
It seems in some cases procs_running field of /proc/stat can contain 0 even if vmstat itself is running. At least this can be reproduced on Linux 3.9.3 compiled with BFS scheduler.
Since getstat() decrements value of procs_running by 1, we get overflow:
$ vmstat 1
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
0 0 667732 918996 57376 911260 21 30 36 40 98 45 14 82 4 1
4294967295 0 667728 916716 57376 911264 8 0 8 0 1958 3733 28 7 65 1
0 0 667700 915996 57376 911416 24 0 152 0 1735 3600 23 5 71 1
4294967295 0 667700 915872 57376 911392 0 0 0 0 1528 3165 21 4 76 0
Function getbtime() currently makes the assumption that btime==0 equals
btime not being present in /proc/stat. This is not quite accurate, as
timestamp 0 is, in fact, also a valid time (Epoch), and /proc/stat may
report it as such.
We introduce a flag to indicate whether btime was found in /proc/stat.
In this way, btime==0 becomes a valid case, provided /proc/stat
actually reports this as the boot time.
procps can still detect the case of btime actually not being reported
by the kernel.
Signed-off-by: Markus Mayer <mmayer@broadcom.com>
An earlier commit attempted to cleanse our environment
of all useless trailing whitespace. But the effort did
not catch 'empty' lines with a single space before ^J.
This commit hopefully finishes off the earlier effort.
In the meantime, let's pray that contributors' editors
are configured so that such wasted crap is disallowed!
Reference(s):
commit fe75e26ab6
Signed-off-by: Jim Warner <james.warner@comcast.net>
The entire tree's polluted with inappropriate trailing
whitespace. This commit rids our environment of all of
those useless keystrokes. Unfortunately, it sure ain't
a permanent solution and requires every contributor to
instruct their editor(s) to prevent or eliminate them.
Plus it's strongly recommended we all insert something
like what's shown below to our '.gitconfig' file so as
to provide at least some warnings when we try to apply
any patches (git am) that do contain the #@!%& things!
References(s):
~/.gitconfig excerpt ---------------------------------
[core]
whitespace = trailing-space, space-before-tab, blank-at-eof
[apply]
whitespace = warn
--------------------------------- ~/.gitconfig excerpt
Signed-off-by: Jim Warner <james.warner@comcast.net>
The problem is that in ./proc/sysinfo.c uptime(), it is not
considered that the "savelocale" string is overwritten by the
subsequent call to setlocale(). Hence restoring the locale later on
won't work this way. "savelocale" ought to be a copy of the string
pointed to by setlocale()'s return-value.
Bug-Redhat: https://bugzilla.redhat.com/show_bug.cgi?id=548711
Backported-by: Sami Kerola <kerolasa@iki.fi>
There were numerous library memory allocation inconsistencies.
Some were checked for failure and others were not.
All library source modules were modified to utilize the alloc.h
memory rouines which are consistent in dealing with errors.
configure.ac now set to 3.3.1
vmstat -p has not worked for a long time, this applies Debian patch
vmstat_part_format, the details:
Author: Daniel Novotny
Description: The contents of /proc/diskstats have changed since 2.6.25
Changed PATH_MAX to 32 because its missing on hurd
Bug-Redhat: https://bugzilla.redhat.com/show_bug.cgi?id=485243
Bug-Debian: http://bugs.debian.org/588677
Last-Update: 2010-11-17
For the small number of devices that we cannot get Hertz out of ELF
notes but the cpu numbers make sense (ie not kFreeBSD) there is a hack
by using the CPU numbers. The problem is there was 4 numbers, now there
are 7. This fixes the hack by adding all 7 to get a more correct number.
This is from Debian patch sysinfo_7_numbers
Bug-Debian: http://bugs.debian.org/460331
FreeBSD has no good way of finding the Hertz value. ELF notes don't
work, you can't find it in a function and even asm/params.h does
not have it. Lucky for us, it is always 100.
Based upon Debian patch patch sysinfo_kfreebsd_hertz by Petr Salinger
Bug-Debian: http://bugs.debian.org/460331
Caution, 460331 has lots of overlapping bugs all around the Hertz
problem across many arches.
