1 files changed, 0 insertions, 311 deletions
diff --git a/memfd/fuse_test.c b/memfd/fuse_test.c
deleted file mode 100644
index 67908b1..0000000
--- a/memfd/fuse_test.c
+++ /dev/null
@@ -1,311 +0,0 @@
-/*
- * memfd GUP test-case
- * This tests memfd interactions with get_user_pages(). We require the
- * fuse_mnt.c program to provide a fake direct-IO FUSE mount-point for us. This
- * file-system delays _all_ reads by 1s and forces direct-IO. This means, any
- * read() on files in that file-system will pin the receive-buffer pages for at
- * least 1s via get_user_pages().
- *
- * We use this trick to race ADD_SEALS against a write on a memfd object. The
- * ADD_SEALS must fail if the memfd pages are still pinned. Note that we use
- * the read() syscall with our memory-mapped memfd object as receive buffer to
- * force the kernel to write into our memfd object.
- */
-
-#define _GNU_SOURCE
-#define __EXPORTED_HEADERS__
-
-#include <errno.h>
-#include <inttypes.h>
-#include <limits.h>
-#include <linux/falloc.h>
-#include <linux/fcntl.h>
-#include <linux/memfd.h>
-#include <sched.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <signal.h>
-#include <string.h>
-#include <sys/mman.h>
-#include <sys/stat.h>
-#include <sys/syscall.h>
-#include <sys/wait.h>
-#include <unistd.h>
-
-#define MFD_DEF_SIZE 8192
-#define STACK_SIZE 65535
-
-static int sys_memfd_create(const char *name,
-			    unsigned int flags)
-{
-	return syscall(__NR_memfd_create, name, flags);
-}
-
-static int mfd_assert_new(const char *name, loff_t sz, unsigned int flags)
-{
-	int r, fd;
-
-	fd = sys_memfd_create(name, flags);
-	if (fd < 0) {
-		printf("memfd_create(\"%s\", %u) failed: %m\n",
-		       name, flags);
-		abort();
-	}
-
-	r = ftruncate(fd, sz);
-	if (r < 0) {
-		printf("ftruncate(%llu) failed: %m\n", (unsigned long long)sz);
-		abort();
-	}
-
-	return fd;
-}
-
-static __u64 mfd_assert_get_seals(int fd)
-{
-	long r;
-
-	r = fcntl(fd, F_GET_SEALS);
-	if (r < 0) {
-		printf("GET_SEALS(%d) failed: %m\n", fd);
-		abort();
-	}
-
-	return r;
-}
-
-static void mfd_assert_has_seals(int fd, __u64 seals)
-{
-	__u64 s;
-
-	s = mfd_assert_get_seals(fd);
-	if (s != seals) {
-		printf("%llu != %llu = GET_SEALS(%d)\n",
-		       (unsigned long long)seals, (unsigned long long)s, fd);
-		abort();
-	}
-}
-
-static void mfd_assert_add_seals(int fd, __u64 seals)
-{
-	long r;
-	__u64 s;
-
-	s = mfd_assert_get_seals(fd);
-	r = fcntl(fd, F_ADD_SEALS, seals);
-	if (r < 0) {
-		printf("ADD_SEALS(%d, %llu -> %llu) failed: %m\n",
-		       fd, (unsigned long long)s, (unsigned long long)seals);
-		abort();
-	}
-}
-
-static int mfd_busy_add_seals(int fd, __u64 seals)
-{
-	long r;
-	__u64 s;
-
-	r = fcntl(fd, F_GET_SEALS);
-	if (r < 0)
-		s = 0;
-	else
-		s = r;
-
-	r = fcntl(fd, F_ADD_SEALS, seals);
-	if (r < 0 && errno != EBUSY) {
-		printf("ADD_SEALS(%d, %llu -> %llu) didn't fail as expected with EBUSY: %m\n",
-		       fd, (unsigned long long)s, (unsigned long long)seals);
-		abort();
-	}
-
-	return r;
-}
-
-static void *mfd_assert_mmap_shared(int fd)
-{
-	void *p;
-
-	p = mmap(NULL,
-		 MFD_DEF_SIZE,
-		 PROT_READ | PROT_WRITE,
-		 MAP_SHARED,
-		 fd,
-		 0);
-	if (p == MAP_FAILED) {
-		printf("mmap() failed: %m\n");
-		abort();
-	}
-
-	return p;
-}
-
-static void *mfd_assert_mmap_private(int fd)
-{
-	void *p;
-
-	p = mmap(NULL,
-		 MFD_DEF_SIZE,
-		 PROT_READ | PROT_WRITE,
-		 MAP_PRIVATE,
-		 fd,
-		 0);
-	if (p == MAP_FAILED) {
-		printf("mmap() failed: %m\n");
-		abort();
-	}
-
-	return p;
-}
-
-static int global_mfd = -1;
-static void *global_p = NULL;
-
-static int sealing_thread_fn(void *arg)
-{
-	int sig, r;
-
-	/*
-	 * This thread first waits 200ms so any pending operation in the parent
-	 * is correctly started. After that, it tries to seal @global_mfd as
-	 * SEAL_WRITE. This _must_ fail as the parent thread has a read() into
-	 * that memory mapped object still ongoing.
-	 * We then wait one more second and try sealing again. This time it
-	 * must succeed as there shouldn't be anyone else pinning the pages.
-	 */
-
-	/* wait 200ms for FUSE-request to be active */
-	usleep(200000);
-
-	/* unmount mapping before sealing to avoid i_mmap_writable failures */
-	munmap(global_p, MFD_DEF_SIZE);
-
-	/* Try sealing the global file; expect EBUSY or success. Current
-	 * kernels will never succeed, but in the future, kernels might
-	 * implement page-replacements or other fancy ways to avoid racing
-	 * writes. */
-	r = mfd_busy_add_seals(global_mfd, F_SEAL_WRITE);
-	if (r >= 0) {
-		printf("HURRAY! This kernel fixed GUP races!\n");
-	} else {
-		/* wait 1s more so the FUSE-request is done */
-		sleep(1);
-
-		/* try sealing the global file again */
-		mfd_assert_add_seals(global_mfd, F_SEAL_WRITE);
-	}
-
-	return 0;
-}
-
-static pid_t spawn_sealing_thread(void)
-{
-	uint8_t *stack;
-	pid_t pid;
-
-	stack = malloc(STACK_SIZE);
-	if (!stack) {
-		printf("malloc(STACK_SIZE) failed: %m\n");
-		abort();
-	}
-
-	pid = clone(sealing_thread_fn,
-		    stack + STACK_SIZE,
-		    SIGCHLD | CLONE_FILES | CLONE_FS | CLONE_VM,
-		    NULL);
-	if (pid < 0) {
-		printf("clone() failed: %m\n");
-		abort();
-	}
-
-	return pid;
-}
-
-static void join_sealing_thread(pid_t pid)
-{
-	waitpid(pid, NULL, 0);
-}
-
-int main(int argc, char **argv)
-{
-	static const char zero[MFD_DEF_SIZE];
-	int fd, mfd, r;
-	void *p;
-	int was_sealed;
-	pid_t pid;
-
-	if (argc < 2) {
-		printf("error: please pass path to file in fuse_mnt mount-point\n");
-		abort();
-	}
-
-	/* open FUSE memfd file for GUP testing */
-	printf("opening: %s\n", argv[1]);
-	fd = open(argv[1], O_RDONLY | O_CLOEXEC);
-	if (fd < 0) {
-		printf("cannot open(\"%s\"): %m\n", argv[1]);
-		abort();
-	}
-
-	/* create new memfd-object */
-	mfd = mfd_assert_new("kern_memfd_fuse",
-			     MFD_DEF_SIZE,
-			     MFD_CLOEXEC | MFD_ALLOW_SEALING);
-
-	/* mmap memfd-object for writing */
-	p = mfd_assert_mmap_shared(mfd);
-
-	/* pass mfd+mapping to a separate sealing-thread which tries to seal
-	 * the memfd objects with SEAL_WRITE while we write into it */
-	global_mfd = mfd;
-	global_p = p;
-	pid = spawn_sealing_thread();
-
-	/* Use read() on the FUSE file to read into our memory-mapped memfd
-	 * object. This races the other thread which tries to seal the
-	 * memfd-object.
-	 * If @fd is on the memfd-fake-FUSE-FS, the read() is delayed by 1s.
-	 * This guarantees that the receive-buffer is pinned for 1s until the
-	 * data is written into it. The racing ADD_SEALS should thus fail as
-	 * the pages are still pinned. */
-	r = read(fd, p, MFD_DEF_SIZE);
-	if (r < 0) {
-		printf("read() failed: %m\n");
-		abort();
-	} else if (!r) {
-		printf("unexpected EOF on read()\n");
-		abort();
-	}
-
-	was_sealed = mfd_assert_get_seals(mfd) & F_SEAL_WRITE;
-
-	/* Wait for sealing-thread to finish and verify that it
-	 * successfully sealed the file after the second try. */
-	join_sealing_thread(pid);
-	mfd_assert_has_seals(mfd, F_SEAL_WRITE);
-
-	/* *IF* the memfd-object was sealed at the time our read() returned,
-	 * then the kernel did a page-replacement or canceled the read() (or
-	 * whatever magic it did..). In that case, the memfd object is still
-	 * all zero.
-	 * In case the memfd-object was *not* sealed, the read() was successfull
-	 * and the memfd object must *not* be all zero.
-	 * Note that in real scenarios, there might be a mixture of both, but
-	 * in this test-cases, we have explicit 200ms delays which should be
-	 * enough to avoid any in-flight writes. */
-
-	p = mfd_assert_mmap_private(mfd);
-	if (was_sealed && memcmp(p, zero, MFD_DEF_SIZE)) {
-		printf("memfd sealed during read() but data not discarded\n");
-		abort();
-	} else if (!was_sealed && !memcmp(p, zero, MFD_DEF_SIZE)) {
-		printf("memfd sealed after read() but data discarded\n");
-		abort();
-	}
-
-	close(mfd);
-	close(fd);
-
-	printf("fuse: DONE\n");
-
-	return 0;
-}