Greg Kroah-Hartman
598cf27219
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
54 lines
1.7 KiB
C
54 lines
1.7 KiB
C
/*
|
|
* Copyright (c) 2024 Alexey Dobriyan <adobriyan@gmail.com>
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
/* Test that kernel thread is reported as such. */
|
|
#undef NDEBUG
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
int main(void)
|
|
{
|
|
/*
|
|
* The following solutions don't really work:
|
|
*
|
|
* 1) jit kernel module which creates kernel thread:
|
|
* test becomes arch-specific,
|
|
* problems with mandatory module signing,
|
|
* problems with lockdown mode,
|
|
* doesn't work with CONFIG_MODULES=n at all,
|
|
* kthread creation API is formally unstable internal kernel API,
|
|
* need a mechanism to report test kernel thread's PID back,
|
|
*
|
|
* 2) ksoftirqd/0 and kswapd0 look like stable enough kernel threads,
|
|
* but their PIDs are unstable.
|
|
*
|
|
* Check against kthreadd which always seem to exist under pid 2.
|
|
*/
|
|
int fd = open("/proc/2/status", O_RDONLY);
|
|
assert(fd >= 0);
|
|
|
|
char buf[4096];
|
|
ssize_t rv = read(fd, buf, sizeof(buf));
|
|
assert(0 <= rv && rv < sizeof(buf));
|
|
buf[rv] = '\0';
|
|
|
|
assert(strstr(buf, "Kthread:\t1\n"));
|
|
|
|
return 0;
|
|
}
|