In the commit referenced below, I fixed what I thought
was all the top 'truncation' warnings. For that commit
I had been using CFLAGS='-ggdb -Wall'. However, if one
uses just a vanilla './configure', then a hidden extra
warning will surface. This patch will finally kill it.
[ thanks a bunch gcc - we love this kind of behavior ]
Reference(s):
. 01/08/22, original warning fix
commit 44ca06f1a0
Signed-off-by: Jim Warner <james.warner@comcast.net>
[ and in the affected function, we'll also eliminate ]
[ all those f**king tab characters making a hot mess ]
[ of any attempt at a properly formatted C function! ]
[ plus i adjusted a little non-tab misalignment too! ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
Since gcc no longer warns of 'unreachable code', we'll
just deal with any such possibility ourselves I guess.
Signed-off-by: Jim Warner <james.warner@comcast.net>
This started off with fixing the compilier warning:
proc/readproc.c: In function ‘simple_nextpid’:
proc/readproc.c:1373:38: warning: ‘%s’ directive output may be truncated writing up to 255 bytes into a region of size 58 [-Wformat-truncation=]
1373 | snprintf(path, PROCPATHLEN, "/proc/%s", ent->d_name);
| ^~
proc/readproc.c:1373:3: note: ‘snprintf’ output between 7 and 262 bytes into a destination of size 64
1373 | snprintf(path, PROCPATHLEN, "/proc/%s", ent->d_name);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We know that ent->d_name will fit under 64 bytes because we check the
name starts with a digit. The first change was simple and changed the
printf to use tgid like the task function below it.
Is everything under /proc that starts with a digit a directory with a
PID only? Today, it is but there are no guarantees.
The entire function works ok if every non-pid directory doesn't start
with a number. We don't check for strtoul() having an issue nor
if the for loop just falls off the end. The moment the kernel guys
(or some module writer) think "/proc/12mykernelval" is a neat idea this
function is in trouble. We won't get buffer overflow as we are
using snprintf at least.
This change now:
We check if strtoul() actually came across a number
Process the pid directory as a conditional branch
Treat falling off the for loop as a not-found
Signed-off-by: Craig Small <csmall@dropbear.xyz>
/usr/include/x86_64-linux-gnu/bits/error.h:40:5: warning: ‘%s’ directive argument is null [-Wformat-overflow=]
40 | __error_noreturn (__status, __errnum, __format, __va_arg_pack ());
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pmap.c: In function ‘main’:
pmap.c:760:35: note: format string is defined here
760 | xerrx(EXIT_FAILURE, "%s: '%s'", _("failed to parse argument"), optarg);
A simple check for optarg being null silenced this, not sure why only
this one was a problem.
Signed-off-by: Craig Small <csmall@dropbear.xyz>
[ you wouldn't believe how many back-and-forths were ]
[ involved in Craig convincing me there were several ]
[ inconsistencies. i am so dense sometimes (often?). ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
This patch was prompted by Björn Fischer's merge #147
request referenced below. And since the library change
may impact all users, multiple man pages were updated.
[ and thanks to Björn for initiating this extension ]
Reference(s):
https://gitlab.com/procps-ng/procps/-/merge_requests/147
Prototyped-by: Björn Fischer <bf@CeBiTec.Uni-Bielefeld.DE>
Signed-off-by: Jim Warner <james.warner@comcast.net>
This patch was prompted by Björn Fischer's merge #147
request referenced below. It has been generalized such
that it now embraces both of those 'pids_fetch' types.
[ and thanks to Björn for initiating this extension ]
Reference(s):
https://gitlab.com/procps-ng/procps/-/merge_requests/147
Prototyped-by: Björn Fischer <bf@CeBiTec.Uni-Bielefeld.DE>
Signed-off-by: Jim Warner <james.warner@comcast.net>
Over the years the summary_show function has increased
from around 77 lines of code & comments to its current
size of 243 lines. This is well beyond an ideal length
of available screen rows. So this patch will split it.
We'll take the cpu and memory duties and make separate
functions out of them. Of course, this will incur some
additional call overhead but, given current cpu/memory
logic, any such increase really becomes insignificant.
Now summary_show's a svelte 57 lines of code/comments.
[ this is like what was done to that do_key function ]
[ a decade ago except overhead of new function calls ]
[ plus table lookup was even less of a concern since ]
[ a human was involved, not normal iterative output. ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
In the patch referenced below the focus task logic was
improved to ensure that newly cloned tasks 'above' the
focused task did not force an effect like the up arrow
key. That commit also acknowledged that when some task
'above' ended, it *would* act like the down arrow key.
Well, with this commit a task ending 'above' a focused
task no longer distorts the focus. That's assuming the
new '#define FOCUS_HARD_Y' is specified plus the total
focused tasks does not exceed the current screen rows.
Thus, the manual scrolling with up and down arrow keys
is allowed when the total focused exceeds screen rows.
[ but keep in mind that when a focused task has been ]
[ hardened some otherwise useful toggles will not be ]
[ available. keystrokes like 'v' and even 'F' itself ]
[ can not be applied to another task with no scroll. ]
Reference(s):
. Sep, 2021 - 'focus' logic improved
commit 69978e3650
Signed-off-by: Jim Warner <james.warner@comcast.net>
This just updates the copyright dates in the documents
where I was already represented. Others are unchanged.
Signed-off-by: Jim Warner <james.warner@comcast.net>
As the issue cited below illustrates, a pids namespace
with proc mounted as subset=pid denies our library any
access to non-task data. In top's case, the result was
a fatal error message which involved "cpu statistics".
With this patch top will now assume an error involving
global cpu (stat) or memory (meminfo) data means we're
running under a restricted pids namespace. As such, an
attempt will be made to still display task level data.
[ if our assumption is incorrect, it's of no matter. ]
[ instead of a fatal error, we'll still try to offer ]
[ a user some minimally useful bit of functionality. ]
Reference(s):
https://gitlab.com/procps-ng/procps/-/issues/227https://www.freelists.org/post/procps/three-for-newlib,1
. 1st cut at subset=pid
commit bcb837b8c7
Signed-off-by: Jim Warner <james.warner@comcast.net>
For some unknown reason all the 'info' structures were
declared between macros and function prototypes rather
than right after all the other structure declarations.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Not only does that library tweak help to simplify some
top code, but now that ps snprintf fmtstr will finally
be accurate. That is two birdies with a single pebble!
Signed-off-by: Jim Warner <james.warner@comcast.net>
This change is really being made on behalf of the ps &
top programs. Besides, over 2 billion CPUs are plenty!
Signed-off-by: Jim Warner <james.warner@comcast.net>
The procfs mount option subset=pid only shows the processes, not things
such as /proc/stat etc.
For certain programs, this should mean they still work, but have reduced
functionality. This is the first cut at some of them.
pgrep - Removed always loading uptime which we never used anyway. The
program now works fine unless we use --older. Add note in man page
stating it will silently fail.
ps - Load boot time and memory total only when required instead of
always. Changed the error messages to something the user actually
cares about "can't get system boot time" vs "create a structure".
Works for most fields except starts and percent memory.
uptime - Give more useful error messages if uptime not available.
vmstat - move header generation after testing for required proc
files, makes the default output more consistent with the rest
of the options.
References:
procps-ng/procps#227https://www.kernel.org/doc/html/latest/filesystems/proc.html#chapter-4-configuring-procfs6814ef2d99
Signed-off-by: Craig Small <csmall@dropbear.xyz>
While the kernel calls the fields pgpgin and pgpgout, the units
here are not pages, but KiB (or 2x 512 sectors).
The comments come from the referenced merged request, this commit fixes
the "vmstat -s lies" part:
https://elixir.bootlin.com/linux/v5.15-rc7/source/block/blk-core.c#L1057
has submit_bio() which includes the count_vm_events(PGPGIN, count) but what
is count? it is usually what bio_sectors() returns.
bio_sectors() is a macro in
https://elixir.bootlin.com/linux/v5.15-rc7/source/include/linux/bio.h#L49
that defines that as bio->bi_iter.bi_size >> 9. 2^9 is 512 or the sector
size. So our count is incremented by the number of 512-byte sectors.
As @dublio has already pointed out before this result is printed to vmstat,
it is /= 2 to give the number of kibibytes (as the sectors were 512 bytes,
we now made the block size 2*512 or 1024). The code even has
"sectors -> kbytes".
So unless there is something very strange going on, pgpgin and pgpgout in
/proc/vmstat return kibibytes.
What about pages (which is sort of implied in the name) or blocks (as
described on the man page)?
Pages can vary, but they are generally 4 KiB so they're out. That also means
vmstat -s lies :(
Blocks are harder to discount. While these too can vary, they can be 1 KiB;
they could also be something else (e.g dd its 512, filesystems 4096).
However, for memory management inside the kernel, there are sectors and
there are (near userland export) KiB, nothing else. It's probably more
accurate to say sectors are shifted in and out of block devices and the
kernel expresses these transfers to userland as KiB by halving the numbers.
What all this means is that using KiB for bi/bo aka pgpgin/pgpgout is more
accurate than saying blocks or pages.
Signed-off-by: Craig Small <csmall@dropbear.xyz>
References:
procps-ng/procps!64
/proc/vmstat provide kbytes to pgpgin and pgpgout instead of blocks,
correct unit for bi/bo.
References:
procps-ng/procps!64
Signed-off-by: Weiping Zhang <zhangweiping@didichuxing.com>
Signed-off-by: Craig Small <csmall@dropbear.xyz>
Our new library's now well protected against potential
problems which arise when a multi-threaded application
opens more than one context within the same API at the
same time. However, with a single-threaded application
designed along those same lines, some problems remain.
So, to avoid potential corruption of some data (which
was classified as local 'static __thread') from those
single-threaded designs, we'll move several variables
to the info structure itself and remove the '__thread'
qualifier. Now they're protected against both designs.
[ we'll not be protected against some multi-threaded ]
[ application that shares a single context yet calls ]
[ that interface from separate threads. this is just ]
[ bad application design & no different than sharing ]
[ other modifiable global data between such threads! ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
upminutes and uphours could both not get initialised in the
procps_uptime_sprint_short() function.
Error was probably introduced at the referenced commit.
References:
Coverity 240787 Uninitialized scalar variable
Coverity 240776 Uninitialized scalar variable
commit 0496b39876
Signed-off-by: Craig Small <csmall@dropbear.xyz>
do_regcomp() error message didn't use a string literal for the format string.
pgrep.c:538:24: error: format not a string literal and no format arguments
[-Werror=format-security]
Signed-off-by: Craig Small <csmall@dropbear.xyz>
99126 Explicit null dereferenced
Not 100% sure this is valid (the same branch that sets the variable
is the one that sets N_option) but not too hard to fix.
Signed-off-by: Craig Small <csmall@dropbear.xyz>
The separate threads for background updates were added
to top in the commit shown below. At that time cleanup
logic was added to end-of-job processing to cancel any
active threads and destroy any semaphores then in use.
That seemed like simple good stewardship with an added
benefit of avoiding potential valgrind 'possibly lost'
warnings for 320 byte blocks. Those blocks represented
an initial stack allocation for each of three threads.
All of that worked perfectly if such code was executed
under the main thread. In other words, if the keyboard
or a signal directed to any thread was used to trigger
program end. However, it might not always be the case.
Each of those 'refresh' routines supporting a separate
thread interacts with a newlib interface. As a result,
each is required to check the library's return result.
Should some error be detected, 'error_exit' is called.
Now we've got big problems with that eoj cleanup code.
One can't 'pthread_cancel' and 'pthread_join' a thread
from withing that same thread. Thus, when an error was
returned by the library with threads active, top would
hang with no possibility of removal short of a reboot.
So, this commit only executes that cancel/join cleanup
code when we are running under the main thread. Should
program end be triggered by a library error under some
sibling thread, all such cleanup will now be bypassed.
In the latter case, we will rely on documentation that
says any thread calling exit(3) will end every thread.
[ now, the only time we'll see any valgrind warnings ]
[ is with a library error, which is the least likely ]
[ scenario for running valgrind & top to begin with. ]
[ besides, if the valgrind warnings became a problem ]
[ one could easily add a 'warning-suppression' file. ]
Reference(s):
. Sep 2021, top introduced threads
commit 29f0a674a8
Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit will place the 'file2strvec' function on a
par with the 'file2str' function if ENOMEM was raised.
Plus, just to keep coverity happy, we'll also clean up
after potential failures with the 'openproc' function.
Signed-off-by: Jim Warner <james.warner@comcast.net>
You can match or filter on cgroup paths. Currently the match is only
done for version 2 cgroups because these are way simpler as they have
a unified name and always start with "0::".
cgroup v1 can have:
named groups "1:name=myspecialname:"
controllers "9:blkio:"
multiple controllers! "4:cpu,cpuacct:"
So they are very much more complicated from a options parsing and
cgroup matching point of view.
In addition, both my Debian bookworm and bullseye systems use
v2 cgroups.
$ ./pgrep --cgroup /system.slice/cron.service
760
Signed-off-by: Craig Small <csmall@dropbear.xyz>
This MR revisits a partial fix from 2018. The problem stems from incorrect
handling of unsigned 32-bit uid_ts and gid_ts as signed when values are
large - i.e. when the high bit is set. In that case, pgrep and pkill fail to
identify processes by uid. (They succeed when finding the same processes by
username.) The primary fix for this is to impliment the "FIXME" comment in
proc/readproc.h, the implementation of which allows the removal of the (int)
casts from the partial fix from 2018.
The other fixed code in this MR consists of tests in strict_atol() that
detects and errors out on overflows.
References:
Merge !146
With the addition of more '__thread' attributes in the
previous commit, additional valgrind warnings might be
encountered if developing multi-threaded applications.
So, this patch expands the libproc.supp file which was
originally introduced with the patch referenced below.
Reference(s):
commit be1ddc2756
Signed-off-by: Jim Warner <james.warner@comcast.net>
In the commit referenced below, a '__thread' attribute
was added to numerous static variables to protect them
from concurrent access conflicts with multi-threading.
Unfortunately, that patch did not go quite far enough.
So, this commit adds a few more '__thread' qualifiers.
Reference(s):
commit 23cfb71366
Signed-off-by: Jim Warner <james.warner@comcast.net>
When multi-threading was introduced in the patch shown
below, the former calls to sigprocmask were traded for
a pthread_sigmask call. This was done unconditionally.
As a result, even when those threads weren't enabled a
need to link with libpthread was created. In hindsight
the need should only arise when top is multi-threaded.
This commit will make pthread_sigmask use conditional.
Reference(s):
. 09/2021, separate threads introduced
commit 29f0a674a8
Signed-off-by: Jim Warner <james.warner@comcast.net>
uptime -p would show empty output after 52 weeks of uptime. This commit
is largely the work of Ed but reformatted for newlib branch.
Signed-off-by: Craig Small <csmall@dropbear.xyz>
References:
procps-ng/procps!141procps-ng/procps#217
The first report from vmstat provides statistics since system boot. This is
often thrown out. Thus, this provides a command line option to omit it. The
program still provides <count> reports.
Signed-off-by: Sanskriti Sharma <sansharm@redhat.com>
