[PATCH 5.15 07/86] selftests: kvm: Fix a compile error in selftests/kvm/rseq_test.c

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Jinrong Liang <cloudliang@xxxxxxxxxxx>

commit 561cafebb2cf97b0927b4fb0eba22de6200f682e upstream.

The following warning appears when executing:
	make -C tools/testing/selftests/kvm

rseq_test.c: In function ‘main’:
rseq_test.c:237:33: warning: implicit declaration of function ‘gettid’; did you mean ‘getgid’? [-Wimplicit-function-declaration]
          (void *)(unsigned long)gettid());
                                 ^~~~~~
                                 getgid
/usr/bin/ld: /tmp/ccr5mMko.o: in function `main':
../kvm/tools/testing/selftests/kvm/rseq_test.c:237: undefined reference to `gettid'
collect2: error: ld returned 1 exit status
make: *** [../lib.mk:173: ../kvm/tools/testing/selftests/kvm/rseq_test] Error 1

Use the more compatible syscall(SYS_gettid) instead of gettid() to fix it.
More subsequent reuse may cause it to be wrapped in a lib file.

Signed-off-by: Jinrong Liang <cloudliang@xxxxxxxxxxx>
Message-Id: <20220802071240.84626-1-cloudliang@xxxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 tools/testing/selftests/kvm/rseq_test.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/testing/selftests/kvm/rseq_test.c
+++ b/tools/testing/selftests/kvm/rseq_test.c
@@ -233,7 +233,7 @@ int main(int argc, char *argv[])
 	ucall_init(vm, NULL);
 
 	pthread_create(&migration_thread, NULL, migration_worker,
-		       (void *)(unsigned long)gettid());
+		       (void *)(unsigned long)syscall(SYS_gettid));
 
 	for (i = 0; !done; i++) {
 		vcpu_run(vm, VCPU_ID);