Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - hfs and hfsplus kmap API modernization (Fabio Francesco)

 - make crash-kexec work properly when invoked from an NMI-time panic
   (Valentin Schneider)

 - ntfs bugfixes (Hawkins Jiawei)

 - improve IPC msg scalability by replacing atomic_t's with percpu
   counters (Jiebin Sun)

 - nilfs2 cleanups (Minghao Chi)

 - lots of other single patches all over the tree!

* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
  proc: test how it holds up with mapping'less process
  mailmap: update Frank Rowand email address
  ia64: mca: use strscpy() is more robust and safer
  init/Kconfig: fix unmet direct dependencies
  ia64: update config files
  nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
  fork: remove duplicate included header files
  init/main.c: remove unnecessary (void*) conversions
  proc: mark more files as permanent
  nilfs2: remove the unneeded result variable
  nilfs2: delete unnecessary checks before brelse()
  checkpatch: warn for non-standard fixes tag style
  usr/gen_init_cpio.c: remove unnecessary -1 values from int file
  ipc/msg: mitigate the lock contention with percpu counter
  percpu: add percpu_counter_add_local and percpu_counter_sub_local
  fs/ocfs2: fix repeated words in comments
  relay: use kvcalloc to alloc page array in relay_alloc_page_array
  proc: make config PROC_CHILDREN depend on PROC_FS
  fs: uninline inode_maybe_inc_iversion()
  ...

1 files changed, 20 insertions, 16 deletions

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index acd029b307e4..ca2743f9c634 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -46,7 +46,7 @@
 #include <crypto/hash.h>
 #include "kexec_internal.h"
 
-DEFINE_MUTEX(kexec_mutex);
+atomic_t __kexec_lock = ATOMIC_INIT(0);
 
 /* Per cpu memory for storing cpu states in case of system crash. */
 note_buf_t __percpu *crash_notes;
@@ -809,7 +809,7 @@ static int kimage_load_normal_segment(struct kimage *image,
 		if (result < 0)
 			goto out;
 
-		ptr = kmap(page);
+		ptr = kmap_local_page(page);
 		/* Start with a clear page */
 		clear_page(ptr);
 		ptr += maddr & ~PAGE_MASK;
@@ -822,7 +822,7 @@ static int kimage_load_normal_segment(struct kimage *image,
 			memcpy(ptr, kbuf, uchunk);
 		else
 			result = copy_from_user(ptr, buf, uchunk);
-		kunmap(page);
+		kunmap_local(ptr);
 		if (result) {
 			result = -EFAULT;
 			goto out;
@@ -873,7 +873,7 @@ static int kimage_load_crash_segment(struct kimage *image,
 			goto out;
 		}
 		arch_kexec_post_alloc_pages(page_address(page), 1, 0);
-		ptr = kmap(page);
+		ptr = kmap_local_page(page);
 		ptr += maddr & ~PAGE_MASK;
 		mchunk = min_t(size_t, mbytes,
 				PAGE_SIZE - (maddr & ~PAGE_MASK));
@@ -889,7 +889,7 @@ static int kimage_load_crash_segment(struct kimage *image,
 		else
 			result = copy_from_user(ptr, buf, uchunk);
 		kexec_flush_icache_page(page);
-		kunmap(page);
+		kunmap_local(ptr);
 		arch_kexec_pre_free_pages(page_address(page), 1);
 		if (result) {
 			result = -EFAULT;
@@ -959,7 +959,7 @@ late_initcall(kexec_core_sysctl_init);
  */
 void __noclone __crash_kexec(struct pt_regs *regs)
 {
-	/* Take the kexec_mutex here to prevent sys_kexec_load
+	/* Take the kexec_lock here to prevent sys_kexec_load
 	 * running on one cpu from replacing the crash kernel
 	 * we are using after a panic on a different cpu.
 	 *
@@ -967,7 +967,7 @@ void __noclone __crash_kexec(struct pt_regs *regs)
 	 * of memory the xchg(&kexec_crash_image) would be
 	 * sufficient.  But since I reuse the memory...
 	 */
-	if (mutex_trylock(&kexec_mutex)) {
+	if (kexec_trylock()) {
 		if (kexec_crash_image) {
 			struct pt_regs fixed_regs;
 
@@ -976,7 +976,7 @@ void __noclone __crash_kexec(struct pt_regs *regs)
 			machine_crash_shutdown(&fixed_regs);
 			machine_kexec(kexec_crash_image);
 		}
-		mutex_unlock(&kexec_mutex);
+		kexec_unlock();
 	}
 }
 STACK_FRAME_NON_STANDARD(__crash_kexec);
@@ -1004,14 +1004,17 @@ void crash_kexec(struct pt_regs *regs)
 	}
 }
 
-size_t crash_get_memory_size(void)
+ssize_t crash_get_memory_size(void)
 {
-	size_t size = 0;
+	ssize_t size = 0;
+
+	if (!kexec_trylock())
+		return -EBUSY;
 
-	mutex_lock(&kexec_mutex);
 	if (crashk_res.end != crashk_res.start)
 		size = resource_size(&crashk_res);
-	mutex_unlock(&kexec_mutex);
+
+	kexec_unlock();
 	return size;
 }
 
@@ -1022,7 +1025,8 @@ int crash_shrink_memory(unsigned long new_size)
 	unsigned long old_size;
 	struct resource *ram_res;
 
-	mutex_lock(&kexec_mutex);
+	if (!kexec_trylock())
+		return -EBUSY;
 
 	if (kexec_crash_image) {
 		ret = -ENOENT;
@@ -1060,7 +1064,7 @@ int crash_shrink_memory(unsigned long new_size)
 	insert_resource(&iomem_resource, ram_res);
 
 unlock:
-	mutex_unlock(&kexec_mutex);
+	kexec_unlock();
 	return ret;
 }
 
@@ -1132,7 +1136,7 @@ int kernel_kexec(void)
 {
 	int error = 0;
 
-	if (!mutex_trylock(&kexec_mutex))
+	if (!kexec_trylock())
 		return -EBUSY;
 	if (!kexec_image) {
 		error = -EINVAL;
@@ -1208,6 +1212,6 @@ int kernel_kexec(void)
 #endif
 
  Unlock:
-	mutex_unlock(&kexec_mutex);
+	kexec_unlock();
 	return error;
 }