Merge tag 'linux-kselftest-fixes-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kselftest fixes from Shuah Khan:
 "Build and run-time fixes to pidfd, clone3, and ir tests"

* tag 'linux-kselftest-fixes-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/ir: fix build with ancient kernel headers
  selftests: fixup build warnings in pidfd / clone3 tests
  pidfd: fix test failure due to stack overflow on some arches

1 files changed, 18 insertions, 4 deletions

diff --git a/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c
index 22558524f71c..3fd8e903118f 100644
--- a/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c
@@ -12,6 +12,7 @@
 #include <string.h>
 #include <syscall.h>
 #include <sys/wait.h>
+#include <sys/mman.h>
 
 #include "pidfd.h"
 #include "../kselftest.h"
@@ -80,7 +81,10 @@ static inline int error_check(struct error *err, const char *test_name)
 	return err->code;
 }
 
+#define CHILD_STACK_SIZE 8192
+
 struct child {
+	char *stack;
 	pid_t pid;
 	int   fd;
 };
@@ -89,17 +93,22 @@ static struct child clone_newns(int (*fn)(void *), void *args,
 				struct error *err)
 {
 	static int flags = CLONE_PIDFD | CLONE_NEWPID | CLONE_NEWNS | SIGCHLD;
-	size_t stack_size = 1024;
-	char *stack[1024] = { 0 };
 	struct child ret;
 
 	if (!(flags & CLONE_NEWUSER) && geteuid() != 0)
 		flags |= CLONE_NEWUSER;
 
+	ret.stack = mmap(NULL, CHILD_STACK_SIZE, PROT_READ | PROT_WRITE,
+			 MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0);
+	if (ret.stack == MAP_FAILED) {
+		error_set(err, -1, "mmap of stack failed (errno %d)", errno);
+		return ret;
+	}
+
 #ifdef __ia64__
-	ret.pid = __clone2(fn, stack, stack_size, flags, args, &ret.fd);
+	ret.pid = __clone2(fn, ret.stack, CHILD_STACK_SIZE, flags, args, &ret.fd);
 #else
-	ret.pid = clone(fn, stack + stack_size, flags, args, &ret.fd);
+	ret.pid = clone(fn, ret.stack + CHILD_STACK_SIZE, flags, args, &ret.fd);
 #endif
 
 	if (ret.pid < 0) {
@@ -129,6 +138,11 @@ static inline int child_join(struct child *child, struct error *err)
 	else if (r > 0)
 		error_set(err, r, "child %d reported: %d", child->pid, r);
 
+	if (munmap(child->stack, CHILD_STACK_SIZE)) {
+		error_set(err, -1, "munmap of child stack failed (errno %d)", errno);
+		r = -1;
+	}
+
 	return r;
 }