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Commit d471ce53 authored by Linus Torvalds's avatar Linus Torvalds
Browse files
Pull UML fixes from Richard Weinberger:
 "Special thanks goes to Toralf Föster for continuously testing UML and
  reporting issues!"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: remove dead code
  um: siginfo cleanup
  uml: Fix which_tmpdir failure when /dev/shm is a symlink, and in other edge cases
  um: Fix wait_stub_done() error handling
  um: Mark stub pages mapping with VM_PFNMAP
  um: Fix return value of strnlen_user()
parents 1b050180 9e82d450
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+4 −4
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ extern int setup_signal_stack_sc(unsigned long stack_top, int sig,
				 sigset_t *mask);
extern int setup_signal_stack_si(unsigned long stack_top, int sig,
				 struct k_sigaction *ka,
				 struct pt_regs *regs, siginfo_t *info, 
				 struct pt_regs *regs, struct siginfo *info,
				 sigset_t *mask);

#endif
+2 −2
Original line number Diff line number Diff line
@@ -19,7 +19,7 @@ EXPORT_SYMBOL(unblock_signals);
 * OK, we're invoking a handler
 */
static void handle_signal(struct pt_regs *regs, unsigned long signr,
			 struct k_sigaction *ka, siginfo_t *info)
			 struct k_sigaction *ka, struct siginfo *info)
{
	sigset_t *oldset = sigmask_to_save();
	int singlestep = 0;
@@ -71,7 +71,7 @@ static void handle_signal(struct pt_regs *regs, unsigned long signr,
static int kern_do_signal(struct pt_regs *regs)
{
	struct k_sigaction ka_copy;
	siginfo_t info;
	struct siginfo info;
	int sig, handled_sig = 0;

	while ((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0) {
+1 −1
Original line number Diff line number Diff line
@@ -123,7 +123,7 @@ void uml_setup_stubs(struct mm_struct *mm)
	/* dup_mmap already holds mmap_sem */
	err = install_special_mapping(mm, STUB_START, STUB_END - STUB_START,
				      VM_READ | VM_MAYREAD | VM_EXEC |
				      VM_MAYEXEC | VM_DONTCOPY,
				      VM_MAYEXEC | VM_DONTCOPY | VM_PFNMAP,
				      mm->context.stub_pages);
	if (err) {
		printk(KERN_ERR "install_special_mapping returned %d\n", err);
+1 −1
Original line number Diff line number Diff line
@@ -254,6 +254,6 @@ int strnlen_user(const void __user *str, int len)
	n = buffer_op((unsigned long) str, len, 0, strnlen_chunk, &count);
	if (n == 0)
		return count + 1;
	return -EFAULT;
	return 0;
}
EXPORT_SYMBOL(strnlen_user);
+189 −41
Original line number Diff line number Diff line
@@ -52,6 +52,25 @@ static void __init find_tempdir(void)
	strcat(tempdir, "/");
}

/*
 * Remove bytes from the front of the buffer and refill it so that if there's a
 * partial string that we care about, it will be completed, and we can recognize
 * it.
 */
static int pop(int fd, char *buf, size_t size, size_t npop)
{
	ssize_t n;
	size_t len = strlen(&buf[npop]);

	memmove(buf, &buf[npop], len + 1);
	n = read(fd, &buf[len], size - len - 1);
	if (n < 0)
		return -errno;

	buf[len + n] = '\0';
	return 1;
}

/*
 * This will return 1, with the first character in buf being the
 * character following the next instance of c in the file.  This will
@@ -61,7 +80,6 @@ static void __init find_tempdir(void)
static int next(int fd, char *buf, size_t size, char c)
{
	ssize_t n;
	size_t len;
	char *ptr;

	while ((ptr = strchr(buf, c)) == NULL) {
@@ -74,20 +92,129 @@ static int next(int fd, char *buf, size_t size, char c)
		buf[n] = '\0';
	}

	ptr++;
	len = strlen(ptr);
	memmove(buf, ptr, len + 1);
	return pop(fd, buf, size, ptr - buf + 1);
}

/*
	 * Refill the buffer so that if there's a partial string that we care
	 * about, it will be completed, and we can recognize it.
 * Decode an octal-escaped and space-terminated path of the form used by
 * /proc/mounts. May be used to decode a path in-place. "out" must be at least
 * as large as the input. The output is always null-terminated. "len" gets the
 * length of the output, excluding the trailing null. Returns 0 if a full path
 * was successfully decoded, otherwise an error.
 */
	n = read(fd, &buf[len], size - len - 1);
	if (n < 0)
		return -errno;
static int decode_path(const char *in, char *out, size_t *len)
{
	char *first = out;
	int c;
	int i;
	int ret = -EINVAL;
	while (1) {
		switch (*in) {
		case '\0':
			goto out;

	buf[len + n] = '\0';
	return 1;
		case ' ':
			ret = 0;
			goto out;

		case '\\':
			in++;
			c = 0;
			for (i = 0; i < 3; i++) {
				if (*in < '0' || *in > '7')
					goto out;
				c = (c << 3) | (*in++ - '0');
			}
			*(unsigned char *)out++ = (unsigned char) c;
			break;

		default:
			*out++ = *in++;
			break;
		}
	}

out:
	*out = '\0';
	*len = out - first;
	return ret;
}

/*
 * Computes the length of s when encoded with three-digit octal escape sequences
 * for the characters in chars.
 */
static size_t octal_encoded_length(const char *s, const char *chars)
{
	size_t len = strlen(s);
	while ((s = strpbrk(s, chars)) != NULL) {
		len += 3;
		s++;
	}

	return len;
}

enum {
	OUTCOME_NOTHING_MOUNTED,
	OUTCOME_TMPFS_MOUNT,
	OUTCOME_NON_TMPFS_MOUNT,
};

/* Read a line of /proc/mounts data looking for a tmpfs mount at "path". */
static int read_mount(int fd, char *buf, size_t bufsize, const char *path,
		      int *outcome)
{
	int found;
	int match;
	char *space;
	size_t len;

	enum {
		MATCH_NONE,
		MATCH_EXACT,
		MATCH_PARENT,
	};

	found = next(fd, buf, bufsize, ' ');
	if (found != 1)
		return found;

	/*
	 * If there's no following space in the buffer, then this path is
	 * truncated, so it can't be the one we're looking for.
	 */
	space = strchr(buf, ' ');
	if (space) {
		match = MATCH_NONE;
		if (!decode_path(buf, buf, &len)) {
			if (!strcmp(buf, path))
				match = MATCH_EXACT;
			else if (!strncmp(buf, path, len)
				 && (path[len] == '/' || !strcmp(buf, "/")))
				match = MATCH_PARENT;
		}

		found = pop(fd, buf, bufsize, space - buf + 1);
		if (found != 1)
			return found;

		switch (match) {
		case MATCH_EXACT:
			if (!strncmp(buf, "tmpfs", strlen("tmpfs")))
				*outcome = OUTCOME_TMPFS_MOUNT;
			else
				*outcome = OUTCOME_NON_TMPFS_MOUNT;
			break;

		case MATCH_PARENT:
			/* This mount obscures any previous ones. */
			*outcome = OUTCOME_NOTHING_MOUNTED;
			break;
		}
	}

	return next(fd, buf, bufsize, '\n');
}

/* which_tmpdir is called only during early boot */
@@ -106,8 +233,12 @@ static int checked_tmpdir = 0;
 */
static void which_tmpdir(void)
{
	int fd, found;
	char buf[128] = { '\0' };
	int fd;
	int found;
	int outcome;
	char *path;
	char *buf;
	size_t bufsize;

	if (checked_tmpdir)
		return;
@@ -116,49 +247,66 @@ static void which_tmpdir(void)

	printf("Checking for tmpfs mount on /dev/shm...");

	path = realpath("/dev/shm", NULL);
	if (!path) {
		printf("failed to check real path, errno = %d\n", errno);
		return;
	}
	printf("%s...", path);

	/*
	 * The buffer needs to be able to fit the full octal-escaped path, a
	 * space, and a trailing null in order to successfully decode it.
	 */
	bufsize = octal_encoded_length(path, " \t\n\\") + 2;

	if (bufsize < 128)
		bufsize = 128;

	buf = malloc(bufsize);
	if (!buf) {
		printf("malloc failed, errno = %d\n", errno);
		goto out;
	}
	buf[0] = '\0';

	fd = open("/proc/mounts", O_RDONLY);
	if (fd < 0) {
		printf("failed to open /proc/mounts, errno = %d\n", errno);
		return;
		goto out1;
	}

	outcome = OUTCOME_NOTHING_MOUNTED;
	while (1) {
		found = next(fd, buf, ARRAY_SIZE(buf), ' ');
		if (found != 1)
			break;

		if (!strncmp(buf, "/dev/shm", strlen("/dev/shm")))
			goto found;

		found = next(fd, buf, ARRAY_SIZE(buf), '\n');
		found = read_mount(fd, buf, bufsize, path, &outcome);
		if (found != 1)
			break;
	}

err:
	if (found == 0)
		printf("nothing mounted on /dev/shm\n");
	else if (found < 0)
	if (found < 0) {
		printf("read returned errno %d\n", -found);
	} else {
		switch (outcome) {
		case OUTCOME_TMPFS_MOUNT:
			printf("OK\n");
			default_tmpdir = "/dev/shm";
			break;

out:
	close(fd);

	return;

found:
	found = next(fd, buf, ARRAY_SIZE(buf), ' ');
	if (found != 1)
		goto err;

	if (strncmp(buf, "tmpfs", strlen("tmpfs"))) {
		case OUTCOME_NON_TMPFS_MOUNT:
			printf("not tmpfs\n");
		goto out;
			break;

		default:
			printf("nothing mounted on /dev/shm\n");
			break;
		}
	}

	printf("OK\n");
	default_tmpdir = "/dev/shm";
	goto out;
	close(fd);
out1:
	free(buf);
out:
	free(path);
}

static int __init make_tempfile(const char *template, char **out_tempname,
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