Utilization clamping is a new kernel feature that got merged in 5.3. It
allows controlling the performance of a process by manipulating the
utilization such that the task appears bigger or smaller than what it
really is.
There's a system-wide control to to restrict what maximum values the
process are allowed to use.
Man page added in a later patch attempts to explain the usage in more
detail.
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
This option has valid use cases on virtual consoles. Example:
enabling screen blanking in the same way as `setterm --blank ...`
does.
Signed-off-by: Ivan Mironov <mironov.ivan@gmail.com>
All `eject` tests were failing under ASan, since they call /bin/mount,
which is uninstrumented, but it picks up the instrumented `libblkid`
library, causing ASan to complain:
gcc:
ASan runtime does not come first in initial library list; you should either link runtime to your application or manually preload it with LD_PRELOAD.
eject: unmount of `/home/runner/work/util-linux/util-linux/tests/output/eject/umount-by-disk-mounted-mnt' failed
clang:
/bin/umount: symbol lookup error: /home/runner/work/util-linux/util-linux/.libs/libblkid.so.1: undefined symbol: __sancov_lowest_stack
eject: unmount of `/home/runner/work/util-linux/util-linux/tests/output/eject/umount-by-disk-mounted-mnt' failed
Subsequently, all tests which require the `scsi_debug` module get skipped,
since it's still in use due to the failed umount:
fdisk: align 512/4K ... SKIPPED (cannot remove scsi_debug module (rmmod))
fdisk: align 512/4K +alignment_offset ... SKIPPED (cannot remove scsi_debug module (rmmod))
fdisk: align 512/4K +MD ... SKIPPED (cannot remove scsi_debug module (rmmod))
In case of gcc this can be easily resolved by setting $LD_PRELOAD to the
respective ASan library. clang makes this a bit more difficult, since it
compiles the ASan library statically, so firstly we need to force dynamic
linking (via -shared-asan), and then add the runtime DSO path to the
linker cache, since it's in a non-standard path.
Since the current Ubuntu Focal image in GH Actions is missing the
`kernel-modules-extra` package with the `scsi_debug` module[0], let's
change the distro flag from `ubuntu-20.04` (Focal) to `ubuntu-latest`
(currently Bionic, as Focal is still in the beta phase).
[0] https://github.community/t/missing-scsi-debug-linux-kernel-module-on-gh-actions/157698
fsck.cramfs crashes when extracting a cramfs image with a 16KB blocksize.
The read_buffer is hardcoded for a 4KB blocksize. When using a blocksize
larger than 4KB, the program's code uses indexes that go past the end of the
allocated space for the read_buffer and this causes the crash.
The following changes fix the problem for me in the latest 2.36.1 release of
fsck.cramfs.c. However there are hardcoded values of 4096 in the code that
might cause problems under other circumstances and I have not attempted to
fix those.
[kzak@redhat.com: - some coding style changes to code]
Fixes: https://github.com/karelzak/util-linux/issues/1232
Signed-off-by: ToddRK <ToddRK@example.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
Ubuntu 12.04 LTS (Precise Pangolin) -- from April 2012 to April 2017.
It's more and more difficult to keep code and tests in all details
compatible with it 4 years dead distro.
Signed-off-by: Karel Zak <kzak@redhat.com>
The command "mount -r" was supported for non-root users in very old
mount(8) versions. Unfortunately, in this case libmount replaces all
mount options from command line by options from fstab. We need
exception for MS_RDONLY.
Fixes: https://github.com/karelzak/util-linux/issues/1235
Signed-off-by: Karel Zak <kzak@redhat.com>
gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3 on travis-ci returns:
libuuid/src/unparse.c:42:67: error: ‘restrict’ undeclared here (not in a function)
libuuid/src/unparse.c: In function ‘uuid_fmt’:
Signed-off-by: Karel Zak <kzak@redhat.com>
misc-utils/wipefs.c: In function ‘main’:
misc-utils/wipefs.c:838:3: error: ‘for’ loop initial declarations are only allowed in C99 mode
misc-utils/wipefs.c:838:3: note: use option -std=c99 or -std=gnu99 to compile your code
Signed-off-by: Karel Zak <kzak@redhat.com>
UINT64_MAX is 18446744073709551615, but 2^64 is 18446744073709551616.
We also need to use kbytes in all calculation in the test than bytes
as ipcs by default do not use bytes anymore.
Signed-off-by: Karel Zak <kzak@redhat.com>
The previous commit 7a08784ab0 reduced
number of situation when we need fallback when kbytes calculated for
shmall pages, but there is still possible to see overflows.
This patch add fallback also for kbytes.
Signed-off-by: Karel Zak <kzak@redhat.com>
Linux kernel since 6730e6580177d13f4612767873cb5a533ad63c61 checks for
limits and kernel ipc/utils.h defines
#define IPCMNI_SHIFT 15
#define IPCMNI (1 << IPCMNI_SHIFT)
it means 32768 (aka shortint max). Let's use it in our tests too to
avoid "Invalid argument" when write to /proc/sys/kernel/shmmni.
Signed-off-by: Karel Zak <kzak@redhat.com>
Avoid computing the number of bytes in shmall, by only
computing and printing the number of Kbytes. This avoids
some overflows, e.g.
$ echo "4503599627370496" > /proc/sys/kernel/shmall
$ ipcs -l | grep 'max total shared memory'
Before:
max total shared memory (kbytes) = 18014398509481980
After:
max total shared memory (kbytes) = 18014398509481984
$ echo "99993599627370500" > /proc/sys/kernel/shmall
99993599627370500
$ ipcs -l | grep 'max total shared memory'
Before:
max total shared memory (kbytes) = 18014398509481980
After:
max total shared memory (kbytes) = 399974398509482000
v1->v2:
Print the non-overflow KB value only for IPC_UNIT_KB and
IPC_UNIT_DEFAULT.
This way --bytes and --human options will still get an expected
output
(but not avoiding the overflow).
Signed-off-by: Vasilis Liaskovitis <vliaskovitis@suse.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
It might be useful for security auditing purposes list all possible
mount flags/options including default set which are normally not listed.
This patch adds "--vfs-all" option to list all fs-independent flags
on VFS-OPTIONS column, as well as libmount funcionality to accomplish
it.
i.e.:
$ findmnt -o VFS-OPTIONS
VFS-OPTIONS
rw,relatime
rw,nosuid,nodev,noexec,relatime
rw,nosuid,nodev,noexec,relatime
ro,nosuid,nodev,noexec
...
$ findmnt --vfs-all -o VFS-OPTIONS
VFS-OPTIONS
rw,exec,suid,dev,async,loud,nomand,atime,noiversion,diratime,relatime,nostrictatime,nolazytime,symfollow
rw,noexec,nosuid,nodev,async,loud,nomand,atime,noiversion,diratime,relatime,nostrictatime,nolazytime,symfollow
rw,noexec,nosuid,nodev,async,loud,nomand,atime,noiversion,diratime,relatime,nostrictatime,nolazytime,symfollow
ro,noexec,nosuid,nodev,async,loud,nomand,atime,noiversion,diratime,norelatime,nostrictatime,nolazytime,symfollow
...
[kzak@redhat.com: - cleanup coding style and comments]
Signed-off-by: Roberto Bergantinos Corpas <rbergant@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
Qais Yousef
Ivan Mironov
Karel Zak
Frantisek Sumsal
ToddRK
Shahid Laher
Vasilis Liaskovitis
Roberto Bergantinos Corpas