[CRIU] [PATCH] zdtm: use pthread_create to create a thread

[Tycho Andersen]

On Wed, Sep 09, 2015 at 07:10:41PM +0300, Andrew Vagin wrote:
> If you call clone directly you are responsible for setting up the TLS area yourself.

Whoops, and the test framework uses this of course; sorry about that.
Thanks,

Acked-by: Tycho Andersen <tycho.andersen at canonical.com>

> $ abrt-cli ls  | grep different_creds | wc -l
> 39
> $ gdb -c /var/spool/abrt/ccpp-2015-07-24-10\:21\:14-8014/coredump  different_creds
>  Core was generated by `./different_creds --pidfile=different_creds.pid --outfile=different_creds.out'.
>  Program terminated with signal SIGILL, Illegal instruction.
>  #0  0x00007f86e2d8c7d9 in _dl_x86_64_restore_sse () from /lib64/ld-linux-x86-64.so.2
>  Missing separate debuginfos, use: dnf debuginfo-install glibc-2.21-7.fc22.x86_64 libattr-2.4.47-9.fc22.x86_64 libcap-2.24-7.fc22.x86_64
>  (gdb) bt
>  #0  0x00007f86e2d8c7d9 in _dl_x86_64_restore_sse () from /lib64/ld-linux-x86-64.so.2
>  #1  0x00007f86e2d84add in _dl_fixup () from /lib64/ld-linux-x86-64.so.2
>  #2  0x00007f86e2d8bbc0 in _dl_runtime_resolve () from /lib64/ld-linux-x86-64.so.2
>  #3  0x0000000000402da3 in sys_futex (val3=0, uaddr2=0x0, timeout=0x0, val=0, op=0, uaddr=0x6063f0 <sig_received>) at lock.h:29
>  #4  futex_wait_while (f=0x6063f0 <sig_received>, v=0) at lock.h:121
>  #5  test_waitsig () at test.c:367
>  #6  0x0000000000401c4b in main (argc=<optimized out>, argv=0x7ffce16432f8) at different_creds.c:82
> 
> Reported-by: Mr Jenkins
> Cc: Tycho Andersen <tycho.andersen at canonical.com>
> Signed-off-by: Andrew Vagin <avagin at openvz.org>
> ---
>  test/zdtm/live/static/Makefile          |  1 +
>  test/zdtm/live/static/different_creds.c | 26 ++++++++++++--------------
>  2 files changed, 13 insertions(+), 14 deletions(-)
> 
> diff --git a/test/zdtm/live/static/Makefile b/test/zdtm/live/static/Makefile
> index 67be675..e66d3ca 100644
> --- a/test/zdtm/live/static/Makefile
> +++ b/test/zdtm/live/static/Makefile
> @@ -317,6 +317,7 @@ inotify_system_nodel:	override CFLAGS += -DNODEL
>  pthread00:		override LDLIBS += -pthread
>  pthread01:		override LDLIBS += -pthread
>  pthread02:		override LDLIBS += -pthread
> +different_creds:	override LDLIBS += -pthread
>  sigpending:		override LDLIBS += -pthread
>  sigaltstack:		override LDLIBS += -pthread
>  shm:			override CFLAGS += -DNEW_IPC_NS
> diff --git a/test/zdtm/live/static/different_creds.c b/test/zdtm/live/static/different_creds.c
> index 545dcb3..c9d23c9 100644
> --- a/test/zdtm/live/static/different_creds.c
> +++ b/test/zdtm/live/static/different_creds.c
> @@ -6,13 +6,18 @@
>  #include <sched.h>
>  #include <sys/capability.h>
>  #include <linux/limits.h>
> +#include <pthread.h>
> +#include <syscall.h>
>  
>  #include "zdtmtst.h"
>  
>  const char *test_doc	= "Check that threads with different creds aren't checkpointed";
>  const char *test_author	= "Tycho Andersen <tycho.andersen at canonical.com>";
>  
> -int drop_caps_and_wait(void *arg)
> +#define exit_group(code)	\
> +	syscall(__NR_exit_group, code)
> +
> +void *drop_caps_and_wait(void *arg)
>  {
>  	cap_t caps;
>  	int *pipe = arg;
> @@ -20,7 +25,7 @@ int drop_caps_and_wait(void *arg)
>          caps = cap_get_proc();
>          if (!caps) {
>                  err("cap_get_proc");
> -                return 1;
> +                return NULL;
>          }
>  
>          if (cap_clear_flag(caps, CAP_EFFECTIVE) < 0) {
> @@ -39,18 +44,14 @@ int drop_caps_and_wait(void *arg)
>  		sleep(1000);
>  die:
>          cap_free(caps);
> -        return 1;
> +        return NULL;
>  }
>  
>  int main(int argc, char ** argv)
>  {
> -	pid_t pid;
>  	int ret, pipefd[2];
> -	long clone_flags = CLONE_VM | CLONE_FILES | CLONE_SIGHAND |
> -			   CLONE_THREAD | CLONE_SYSVSEM;
> +	pthread_t thr;
>  
> -        size_t stack_size = sysconf(_SC_PAGESIZE);
> -        void *stack = alloca(stack_size);
>  	char buf;
>  
>  	test_init(argc, argv);
> @@ -60,12 +61,10 @@ int main(int argc, char ** argv)
>  		return -1;
>  	}
>  
> -	pid = clone(drop_caps_and_wait, stack + stack_size, clone_flags, pipefd);
> -	if (pid < 0) {
> -		err("fork");
> +	if (pthread_create(&thr, NULL, drop_caps_and_wait, pipefd)) {
> +		err("Unable to create thread");
>  		return -1;
>  	}
> -
>  	close(pipefd[1]);
>  
>  	/*
> @@ -83,6 +82,5 @@ int main(int argc, char ** argv)
>  
>  	fail("shouldn't dump successfully");
>  
> -	kill(pid, SIGKILL);
> -	return ret;
> +	exit_group(ret);
>  }
> -- 
> 2.4.3
>