Merge tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc updates from Andrew Morton:
 "Updates to various subsystems which I help look after. lib, ocfs2,
  fatfs, autofs, squashfs, procfs, etc. A relatively small amount of
  material this time"

* tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
  scripts/gdb: ensure the absolute path is generated on initial source
  MAINTAINERS: kunit: add David Gow as a maintainer of KUnit
  mailmap: add linux.dev alias for Brendan Higgins
  mailmap: update Kirill's email
  profile: setup_profiling_timer() is moslty not implemented
  ocfs2: fix a typo in a comment
  ocfs2: use the bitmap API to simplify code
  ocfs2: remove some useless functions
  lib/mpi: fix typo 'the the' in comment
  proc: add some (hopefully) insightful comments
  bdi: remove enum wb_congested_state
  kernel/hung_task: fix address space of proc_dohung_task_timeout_secs
  lib/lzo/lzo1x_compress.c: replace ternary operator with min() and min_t()
  squashfs: support reading fragments in readahead call
  squashfs: implement readahead
  squashfs: always build "file direct" version of page actor
  Revert "squashfs: provide backing_dev_info in order to disable read-ahead"
  fs/ocfs2: Fix spelling typo in comment
  ia64: old_rr4 added under CONFIG_HUGETLB_PAGE
  proc: fix test for "vsyscall=xonly" boot option
  ...

8 files changed, 199 insertions, 11 deletions

diff --git a/tools/accounting/getdelays.c b/tools/accounting/getdelays.c
index e83e6e47a21e..938dec0dfaad 100644
--- a/tools/accounting/getdelays.c
+++ b/tools/accounting/getdelays.c
@@ -45,7 +45,6 @@
 		exit(code);			\
 	} while (0)
 
-int done;
 int rcvbufsz;
 char name[100];
 int dbg;
@@ -285,7 +284,6 @@ int main(int argc, char *argv[])
 	pid_t rtid = 0;
 
 	int fd = 0;
-	int count = 0;
 	int write_file = 0;
 	int maskset = 0;
 	char *logfile = NULL;
@@ -495,7 +493,6 @@ int main(int argc, char *argv[])
 				len2 = 0;
 				/* For nested attributes, na follows */
 				na = (struct nlattr *) NLA_DATA(na);
-				done = 0;
 				while (len2 < aggr_len) {
 					switch (na->nla_type) {
 					case TASKSTATS_TYPE_PID:
@@ -509,7 +506,6 @@ int main(int argc, char *argv[])
 							printf("TGID\t%d\n", rtid);
 						break;
 					case TASKSTATS_TYPE_STATS:
-						count++;
 						if (print_delays)
 							print_delayacct((struct taskstats *) NLA_DATA(na));
 						if (print_io_accounting)
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 5047d8eef53e..10b34bb03bc1 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -17,6 +17,7 @@ TARGETS += exec
 TARGETS += filesystems
 TARGETS += filesystems/binderfs
 TARGETS += filesystems/epoll
+TARGETS += filesystems/fat
 TARGETS += firmware
 TARGETS += fpu
 TARGETS += ftrace
diff --git a/tools/testing/selftests/filesystems/fat/.gitignore b/tools/testing/selftests/filesystems/fat/.gitignore
new file mode 100644
index 000000000000..b89920ed841c
--- /dev/null
+++ b/tools/testing/selftests/filesystems/fat/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+rename_exchange
diff --git a/tools/testing/selftests/filesystems/fat/Makefile b/tools/testing/selftests/filesystems/fat/Makefile
new file mode 100644
index 000000000000..902033f6ef09
--- /dev/null
+++ b/tools/testing/selftests/filesystems/fat/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+
+TEST_PROGS := run_fat_tests.sh
+TEST_GEN_PROGS_EXTENDED := rename_exchange
+CFLAGS += -O2 -g -Wall $(KHDR_INCLUDES)
+
+include ../../lib.mk
diff --git a/tools/testing/selftests/filesystems/fat/config b/tools/testing/selftests/filesystems/fat/config
new file mode 100644
index 000000000000..6cf95e787a17
--- /dev/null
+++ b/tools/testing/selftests/filesystems/fat/config
@@ -0,0 +1,2 @@
+CONFIG_BLK_DEV_LOOP=y
+CONFIG_VFAT_FS=y
diff --git a/tools/testing/selftests/filesystems/fat/rename_exchange.c b/tools/testing/selftests/filesystems/fat/rename_exchange.c
new file mode 100644
index 000000000000..e488ad354fce
--- /dev/null
+++ b/tools/testing/selftests/filesystems/fat/rename_exchange.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Program that atomically exchanges two paths using
+ * the renameat2() system call RENAME_EXCHANGE flag.
+ *
+ * Copyright 2022 Red Hat Inc.
+ * Author: Javier Martinez Canillas <javierm@redhat.com>
+ */
+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+void print_usage(const char *program)
+{
+	printf("Usage: %s [oldpath] [newpath]\n", program);
+	printf("Atomically exchange oldpath and newpath\n");
+}
+
+int main(int argc, char *argv[])
+{
+	int ret;
+
+	if (argc != 3) {
+		print_usage(argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
+	ret = renameat2(AT_FDCWD, argv[1], AT_FDCWD, argv[2], RENAME_EXCHANGE);
+	if (ret) {
+		perror("rename exchange failed");
+		exit(EXIT_FAILURE);
+	}
+
+	exit(EXIT_SUCCESS);
+}
diff --git a/tools/testing/selftests/filesystems/fat/run_fat_tests.sh b/tools/testing/selftests/filesystems/fat/run_fat_tests.sh
new file mode 100644
index 000000000000..7f35dc3d15df
--- /dev/null
+++ b/tools/testing/selftests/filesystems/fat/run_fat_tests.sh
@@ -0,0 +1,82 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Run filesystem operations tests on an 1 MiB disk image that is formatted with
+# a vfat filesystem and mounted in a temporary directory using a loop device.
+#
+# Copyright 2022 Red Hat Inc.
+# Author: Javier Martinez Canillas <javierm@redhat.com>
+
+set -e
+set -u
+set -o pipefail
+
+BASE_DIR="$(dirname $0)"
+TMP_DIR="$(mktemp -d /tmp/fat_tests_tmp.XXXX)"
+IMG_PATH="${TMP_DIR}/fat.img"
+MNT_PATH="${TMP_DIR}/mnt"
+
+cleanup()
+{
+    mountpoint -q "${MNT_PATH}" && unmount_image
+    rm -rf "${TMP_DIR}"
+}
+trap cleanup SIGINT SIGTERM EXIT
+
+create_loopback()
+{
+    touch "${IMG_PATH}"
+    chattr +C "${IMG_PATH}" >/dev/null 2>&1 || true
+
+    truncate -s 1M "${IMG_PATH}"
+    mkfs.vfat "${IMG_PATH}" >/dev/null 2>&1
+}
+
+mount_image()
+{
+    mkdir -p "${MNT_PATH}"
+    sudo mount -o loop "${IMG_PATH}" "${MNT_PATH}"
+}
+
+rename_exchange_test()
+{
+    local rename_exchange="${BASE_DIR}/rename_exchange"
+    local old_path="${MNT_PATH}/old_file"
+    local new_path="${MNT_PATH}/new_file"
+
+    echo old | sudo tee "${old_path}" >/dev/null 2>&1
+    echo new | sudo tee "${new_path}" >/dev/null 2>&1
+    sudo "${rename_exchange}" "${old_path}" "${new_path}" >/dev/null 2>&1
+    sudo sync -f "${MNT_PATH}"
+    grep new "${old_path}" >/dev/null 2>&1
+    grep old "${new_path}" >/dev/null 2>&1
+}
+
+rename_exchange_subdir_test()
+{
+    local rename_exchange="${BASE_DIR}/rename_exchange"
+    local dir_path="${MNT_PATH}/subdir"
+    local old_path="${MNT_PATH}/old_file"
+    local new_path="${dir_path}/new_file"
+
+    sudo mkdir -p "${dir_path}"
+    echo old | sudo tee "${old_path}" >/dev/null 2>&1
+    echo new | sudo tee "${new_path}" >/dev/null 2>&1
+    sudo "${rename_exchange}" "${old_path}" "${new_path}" >/dev/null 2>&1
+    sudo sync -f "${MNT_PATH}"
+    grep new "${old_path}" >/dev/null 2>&1
+    grep old "${new_path}" >/dev/null 2>&1
+}
+
+unmount_image()
+{
+    sudo umount "${MNT_PATH}" &> /dev/null
+}
+
+create_loopback
+mount_image
+rename_exchange_test
+rename_exchange_subdir_test
+unmount_image
+
+exit 0
diff --git a/tools/testing/selftests/proc/proc-pid-vm.c b/tools/testing/selftests/proc/proc-pid-vm.c
index 28604c9f805c..e5962f4794f5 100644
--- a/tools/testing/selftests/proc/proc-pid-vm.c
+++ b/tools/testing/selftests/proc/proc-pid-vm.c
@@ -211,10 +211,19 @@ static int make_exe(const uint8_t *payload, size_t len)
 }
 #endif
 
-static bool g_vsyscall = false;
+/*
+ * 0: vsyscall VMA doesn't exist	vsyscall=none
+ * 1: vsyscall VMA is r-xp		vsyscall=emulate
+ * 2: vsyscall VMA is --xp		vsyscall=xonly
+ */
+static int g_vsyscall;
+static const char *str_vsyscall;
 
-static const char str_vsyscall[] =
+static const char str_vsyscall_0[] = "";
+static const char str_vsyscall_1[] =
 "ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]\n";
+static const char str_vsyscall_2[] =
+"ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0                  [vsyscall]\n";
 
 #ifdef __x86_64__
 static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___)
@@ -223,7 +232,7 @@ static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___)
 }
 
 /*
- * vsyscall page can't be unmapped, probe it with memory load.
+ * vsyscall page can't be unmapped, probe it directly.
  */
 static void vsyscall(void)
 {
@@ -246,13 +255,52 @@ static void vsyscall(void)
 		act.sa_sigaction = sigaction_SIGSEGV;
 		(void)sigaction(SIGSEGV, &act, NULL);
 
+		/* gettimeofday(NULL, NULL); */
+		asm volatile (
+			"call %P0"
+			:
+			: "i" (0xffffffffff600000), "D" (NULL), "S" (NULL)
+			: "rax", "rcx", "r11"
+		);
+		exit(0);
+	}
+	waitpid(pid, &wstatus, 0);
+	if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) == 0) {
+		/* vsyscall page exists and is executable. */
+	} else {
+		/* vsyscall page doesn't exist. */
+		g_vsyscall = 0;
+		return;
+	}
+
+	pid = fork();
+	if (pid < 0) {
+		fprintf(stderr, "fork, errno %d\n", errno);
+		exit(1);
+	}
+	if (pid == 0) {
+		struct rlimit rlim = {0, 0};
+		(void)setrlimit(RLIMIT_CORE, &rlim);
+
+		/* Hide "segfault at ffffffffff600000" messages. */
+		struct sigaction act;
+		memset(&act, 0, sizeof(struct sigaction));
+		act.sa_flags = SA_SIGINFO;
+		act.sa_sigaction = sigaction_SIGSEGV;
+		(void)sigaction(SIGSEGV, &act, NULL);
+
 		*(volatile int *)0xffffffffff600000UL;
 		exit(0);
 	}
 	waitpid(pid, &wstatus, 0);
 	if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) == 0) {
-		g_vsyscall = true;
+		/* vsyscall page is readable and executable. */
+		g_vsyscall = 1;
+		return;
 	}
+
+	/* vsyscall page is executable but unreadable. */
+	g_vsyscall = 2;
 }
 
 int main(void)
@@ -261,6 +309,19 @@ int main(void)
 	int exec_fd;
 
 	vsyscall();
+	switch (g_vsyscall) {
+	case 0:
+		str_vsyscall = str_vsyscall_0;
+		break;
+	case 1:
+		str_vsyscall = str_vsyscall_1;
+		break;
+	case 2:
+		str_vsyscall = str_vsyscall_2;
+		break;
+	default:
+		abort();
+	}
 
 	atexit(ate);
 
@@ -314,7 +375,7 @@ int main(void)
 
 	/* Test /proc/$PID/maps */
 	{
-		const size_t len = strlen(buf0) + (g_vsyscall ? strlen(str_vsyscall) : 0);
+		const size_t len = strlen(buf0) + strlen(str_vsyscall);
 		char buf[256];
 		ssize_t rv;
 		int fd;
@@ -327,7 +388,7 @@ int main(void)
 		rv = read(fd, buf, sizeof(buf));
 		assert(rv == len);
 		assert(memcmp(buf, buf0, strlen(buf0)) == 0);
-		if (g_vsyscall) {
+		if (g_vsyscall > 0) {
 			assert(memcmp(buf + strlen(buf0), str_vsyscall, strlen(str_vsyscall)) == 0);
 		}
 	}
@@ -374,7 +435,7 @@ int main(void)
 			assert(memmem(buf, rv, S[i], strlen(S[i])));
 		}
 
-		if (g_vsyscall) {
+		if (g_vsyscall > 0) {
 			assert(memmem(buf, rv, str_vsyscall, strlen(str_vsyscall)));
 		}
 	}