This allows to control mainloop behavior from PTY applications. For
example you can write to child (shell) process independently on the
current stdin.
Signed-off-by: Karel Zak <kzak@redhat.com>
The idea is to consolidate script(1), scriptlive(1) and su(1) --pty
and use the same code everywhere.
TODO: add callbacks for stdin/out logging (necessary for script(1)).
Signed-off-by: Karel Zak <kzak@redhat.com>
Sorry detail-oriented people tend to wipe these out if they notice them.
Add in automated tools and lots of excess end-of-line spaces get wiped
out.
Addresses: https://github.com/karelzak/util-linux/pull/849
Signed-off-by: Karel Zak <kzak@redhat.com>
Add the --keep-caps option to unshare to preserve capabilities that
are granted when creating a new user namespace. This allows the child
process to retain privilege within the new user namespace without also
being UID 0.
In order to avoid closing standard streams multiple times, commit
52aa1a661 (include/closestream: avoid close more than once, 2019-06-13)
introduced code to set the standard output and error streams to `NULL`.
As musl libc defines standard streams as constant pointers, the change
causes compiler errors on systems with that libc. According to ISO C89,
being able to assign to the standard text streams is not a requirement
for any C implementation, see footnote 238 in chapter §7.19.5.6:
The primary use of the freopen function is to change the file
associated with a standard text stream (stderr, stdin, or stdout),
as those identifiers need not be modifiable lvalues to which the
value returned by the fopen function may be assigned.
This commit implements a new function `flush_standard_stream` that tries
to reliably flush standard streams without actually closing them. By not
calling fclose(3P), we can neatly avoid the issue of accessing standard
streams in an unspecified state and thus remove the infringing `NULL`
assignments.
Properly flushing standard streams without fclose(3P) proves to be more
intricate than one may expect, though, as some filesystems like NFS may
defer flushing until they see a close(3P) of the underlying descriptor.
One may call fsync(3P) to remedy that, but this may incur a heavy
performance penalty in some scenarios. To work around the issue and
still get proper errors, we duplicate the stream's file descriptor and
close that one instead, which is sufficient to cause a flush.
Note that both `close_stdout` and `close_stdout_atexit` are misnamed
after this change, as we do not actually close the streams now. In order
to avoid unnecessary code churn, we still retain their current names.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
There are two things happening in this commit. 1) Move each function
attribute to it's own line 2) move function return value after attributes so
that function inputs and outputs are on same line.
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
There is a c_isascii function that can be used.
isascii is deprecated and not available with some libcs like uClibc-ng
where it can be compile time disabled.
Turned out lsblk is passing null as argument to xstrdup(), so fix that and
add assert() to make sure promise of not returning null is kept in future.
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
The device can be inaccessible for non-root user or busy (already used
by another process). In this case it seems better to read information
from /sys.
Note that /sys does not provide struct watchdog_info.options, so we
cannot print list of supported watchdog features.
Addresses: https://github.com/karelzak/util-linux/issues/804
Signed-off-by: Karel Zak <kzak@redhat.com>
Let's use miscdev /dev/watchdog as fallback only. We need (if possible)
cdev /dev/watchdog0 as this device has entry in /sys/class/watchdog.
Signed-off-by: Karel Zak <kzak@redhat.com>
Let's keep compilers and static analyzers happy. The idea is to use
memcpy() to copy from buffer to variable and use all label as unsigned
char rather than vectorize by uint32_t.
Signed-off-by: Karel Zak <kzak@redhat.com>
The __has macros are more portable (supported by gcc as well as
clang).
The old __GNUC_PREREQ is deprecated and it should be removed in
future. (Well, the __has macros are supported since gcc 5, so we
should be patient as some old stable distros (e.g. RHEL 7) use gcc
4.x).
This patch helps clang to correctly analyze our xalloc.h stuff.
Signed-off-by: Karel Zak <kzak@redhat.com>
Recent lscpu fix caused gcc -Wnull-dereference to go off that this change
addresses.
Reference: b94acada9e
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
From the test input string ':' characters are removed:
cat x86_64-epyc_7451/sys/devices/system/cpu/vulnerabilities/spectre_v2
Mitigation: Full AMD retpoline, IBPB: conditional, STIBP: disabled, RSB filling
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
It seems better to have a way to control when atexit(close_stdout()) is
used, because close stdout means that for example ASAN (or another
into binary integrated tool) is not able to print the final summary.
Signed-off-by: Karel Zak <kzak@redhat.com>
This warning is repeated 112 times when compiling with all warnings.
xalloc.h:23:1: warning: function '__err_oom' could be declared with
attribute 'noreturn' [-Wmissing-noreturn]
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
The partition scanner in kernel depends on blocksize. We need to set
the blocksize before we call LOOP_SET_STATUS64 (this ioctl triggers
the scanner).
This patch extends the internal API to save blocksize into loopdev
context to be usable later for loopcxt_setup_device().
Signed-off-by: Karel Zak <kzak@redhat.com>
Now the internal API uses loopcxt_set_...() to set context variables
as well as to call ioctls. This patch introduces loopcxt_ioctl_...()
to makes things more obvious to readers.
Signed-off-by: Karel Zak <kzak@redhat.com>
Assumption all years since 1970 have been exactly 365 days long has it's
problems when leap years happen. Lets use struct tm fields that are
provided by localtime_r(), making year and day to be correctly compared even
when it's late new years eve somewhere else than UTC-0.
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
* add struct ul_timer as API abstraction to hide differences between
timer_create() and setitimer()
* add setitimer() detection to ./configure.ac
* add fallback code to use setitimer() if timer_create() not available
(for example on OSX)
Addresses: https://github.com/karelzak/util-linux/issues/584
Signed-off-by: Karel Zak <kzak@redhat.com>
This reverts parts of commit eb06d5d4, which seems to be based on
Linux kernel commit c7acec71. Unlike the original kernel patch we did
not add that even stronger type checking by using macro BUILD_BUG_ON_MSG.
So basically we removed a useful warning when compiling such
broken code:
struct st {
int a;
char b;
};
struct st t = { .a = 1, .b = 2 };
struct st *x = container_of(&t.a, struct st, b);
printf("%p %p\n", (void *)&t, (void *)x);
Moreover we also introduced a new compiler warning for intel/icc:
"arithmetic on pointer to void or function type"
Let's just revert the update of container_of() because adding a
kernel-like BUILD_BUG_ON_MSG would be too much noise and also
problematic (see kernel commit c03567a8). Also note that the original
problem addressed by the kernel commit seems to be only reproducible
with gcc 4.9, not with any later gcc nor clang,icc. Moreover, currently
we have no such use-case in the UL sources anyways.
Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>
Let the compiler optimize based on the knowledge that the return value will
never be null.
Reference: https://patchwork.ozlabs.org/patch/281112/#631159
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
str2memcpy() - copy zero terminated string to optionally terminated buffer
mem2strcpy() - copy from buffer to zero terminated string
Signed-off-by: Karel Zak <kzak@redhat.com>
Karel Zak
Elliott Mitchell
Quentin Rameau
Sami Kerola
James Peach
Patrick Steinhardt
Rosen Penev
Ruediger Meier
Justin Chen