Merge tag 'mm-hotfixes-stable-2024-01-12-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc hotfixes from Andrew Morton:
 "For once not mostly MM-related.

  17 hotfixes. 10 address post-6.7 issues and the other 7 are cc:stable"

* tag 'mm-hotfixes-stable-2024-01-12-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  userfaultfd: avoid huge_zero_page in UFFDIO_MOVE
  MAINTAINERS: add entry for shrinker
  selftests: mm: hugepage-vmemmap fails on 64K page size systems
  mm/memory_hotplug: fix memmap_on_memory sysfs value retrieval
  mailmap: switch email for Tanzir Hasan
  mailmap: add old address mappings for Randy
  kernel/crash_core.c: make __crash_hotplug_lock static
  efi: disable mirror feature during crashkernel
  kexec: do syscore_shutdown() in kernel_kexec
  mailmap: update entry for Manivannan Sadhasivam
  fs/proc/task_mmu: move mmu notification mechanism inside mm lock
  mm: zswap: switch maintainers to recently active developers and reviewers
  scripts/decode_stacktrace.sh: optionally use LLVM utilities
  kasan: avoid resetting aux_lock
  lib/Kconfig.debug: disable CONFIG_DEBUG_INFO_BTF for Hexagon
  MAINTAINERS: update LTP maintainers
  kdump: defer the insertion of crashkernel resources

4 files changed, 25 insertions, 5 deletions

diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 24c13dfb1e94..df6627f62402 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -487,6 +487,7 @@ void kasan_init_object_meta(struct kmem_cache *cache, const void *object)
 		__memset(alloc_meta, 0, sizeof(*alloc_meta));
 
 		/*
+		 * Prepare the lock for saving auxiliary stack traces.
 		 * Temporarily disable KASAN bug reporting to allow instrumented
 		 * raw_spin_lock_init to access aux_lock, which resides inside
 		 * of a redzone.
@@ -510,8 +511,13 @@ static void release_alloc_meta(struct kasan_alloc_meta *meta)
 	stack_depot_put(meta->aux_stack[0]);
 	stack_depot_put(meta->aux_stack[1]);
 
-	/* Zero out alloc meta to mark it as invalid. */
-	__memset(meta, 0, sizeof(*meta));
+	/*
+	 * Zero out alloc meta to mark it as invalid but keep aux_lock
+	 * initialized to avoid having to reinitialize it when another object
+	 * is allocated in the same slot.
+	 */
+	__memset(&meta->alloc_track, 0, sizeof(meta->alloc_track));
+	__memset(meta->aux_stack, 0, sizeof(meta->aux_stack));
 }
 
 static void release_free_meta(const void *object, struct kasan_free_meta *meta)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index b3c0ff52bb72..21890994c1d3 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -101,9 +101,11 @@ static int set_memmap_mode(const char *val, const struct kernel_param *kp)
 
 static int get_memmap_mode(char *buffer, const struct kernel_param *kp)
 {
-	if (*((int *)kp->arg) == MEMMAP_ON_MEMORY_FORCE)
-		return sprintf(buffer,  "force\n");
-	return param_get_bool(buffer, kp);
+	int mode = *((int *)kp->arg);
+
+	if (mode == MEMMAP_ON_MEMORY_FORCE)
+		return sprintf(buffer, "force\n");
+	return sprintf(buffer, "%c\n", mode ? 'Y' : 'N');
 }
 
 static const struct kernel_param_ops memmap_mode_ops = {
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 89dc29f1e6c6..2c19f5515e36 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -26,6 +26,7 @@
 #include <linux/pgtable.h>
 #include <linux/swap.h>
 #include <linux/cma.h>
+#include <linux/crash_dump.h>
 #include "internal.h"
 #include "slab.h"
 #include "shuffle.h"
@@ -381,6 +382,11 @@ static void __init find_zone_movable_pfns_for_nodes(void)
 			goto out;
 		}
 
+		if (is_kdump_kernel()) {
+			pr_warn("The system is under kdump, ignore kernelcore=mirror.\n");
+			goto out;
+		}
+
 		for_each_mem_region(r) {
 			if (memblock_is_mirror(r))
 				continue;
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 216ab4c8621f..20e3b0d9cf7e 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -1393,6 +1393,12 @@ ssize_t move_pages(struct userfaultfd_ctx *ctx, struct mm_struct *mm,
 				err = -ENOENT;
 				break;
 			}
+			/* Avoid moving zeropages for now */
+			if (is_huge_zero_pmd(*src_pmd)) {
+				spin_unlock(ptl);
+				err = -EBUSY;
+				break;
+			}
 
 			/* Check if we can move the pmd without splitting it. */
 			if (move_splits_huge_pmd(dst_addr, src_addr, src_start + len) ||