Merge tag 'mm-hotfixes-stable-2022-05-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "Seven MM fixes, three of which address issues added in the most recent
  merge window, four of which are cc:stable.

  Three non-MM fixes, none very serious"

[ And yes, that's a real pull request from Andrew, not me creating a
  branch from emailed patches. Woo-hoo! ]

* tag 'mm-hotfixes-stable-2022-05-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  MAINTAINERS: add a mailing list for DAMON development
  selftests: vm: Makefile: rename TARGETS to VMTARGETS
  mm/kfence: reset PG_slab and memcg_data before freeing __kfence_pool
  mailmap: add entry for [email protected]
  arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map
  procfs: prevent unprivileged processes accessing fdinfo dir
  mm: mremap: fix sign for EFAULT error return value
  mm/hwpoison: use pr_err() instead of dump_page() in get_any_page()
  mm/huge_memory: do not overkill when splitting huge_zero_page
  Revert "mm/memory-failure.c: skip huge_zero_page in memory_failure()"

Author: torvalds

.mailmap

@@ -251,6 +251,7 @@ Mark Yao <[email protected]> <[email protected]>
 Martin Kepplinger <[email protected]> <[email protected]>
 Martin Kepplinger <[email protected]> <[email protected]>
 Martin Kepplinger <[email protected]> <[email protected]>
+Martyna Szapar-Mudlaw <[email protected]> <[email protected]>
 Mathieu Othacehe <[email protected]>
 Matthew Wilcox <[email protected]> <[email protected]>
 Matthew Wilcox <[email protected]> <[email protected]>

MAINTAINERS

@@ -5440,6 +5440,7 @@ F:	net/ax25/sysctl_net_ax25.c
 
 DATA ACCESS MONITOR
 M:	SeongJae Park <[email protected]>
+L:	[email protected]
 L:	[email protected]
 S:	Maintained
 F:	Documentation/ABI/testing/sysfs-kernel-mm-damon

arch/arm/include/asm/io.h

@@ -440,6 +440,9 @@ extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
 extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
+extern bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
+					unsigned long flags);
+#define arch_memremap_can_ram_remap arch_memremap_can_ram_remap
 #endif
 
 /*

arch/arm/mm/ioremap.c

@@ -493,3 +493,11 @@ void __init early_ioremap_init(void)
 {
 	early_ioremap_setup();
 }
+
+bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
+				 unsigned long flags)
+{
+	unsigned long pfn = PHYS_PFN(offset);
+
+	return memblock_is_map_memory(pfn);
+}

arch/arm64/include/asm/io.h

@@ -192,4 +192,8 @@ extern void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size);
 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
 extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
 
+extern bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
+					unsigned long flags);
+#define arch_memremap_can_ram_remap arch_memremap_can_ram_remap
+
 #endif	/* __ASM_IO_H */

arch/arm64/mm/ioremap.c

@@ -99,3 +99,11 @@ void __init early_ioremap_init(void)
 {
 	early_ioremap_setup();
 }
+
+bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
+				 unsigned long flags)
+{
+	unsigned long pfn = PHYS_PFN(offset);
+
+	return pfn_is_map_memory(pfn);
+}

fs/proc/fd.c

@@ -72,7 +72,7 @@ static int seq_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static int seq_fdinfo_open(struct inode *inode, struct file *file)
+static int proc_fdinfo_access_allowed(struct inode *inode)
 {
 	bool allowed = false;
 	struct task_struct *task = get_proc_task(inode);
@@ -86,6 +86,16 @@ static int seq_fdinfo_open(struct inode *inode, struct file *file)
 	if (!allowed)
 		return -EACCES;
 
+	return 0;
+}
+
+static int seq_fdinfo_open(struct inode *inode, struct file *file)
+{
+	int ret = proc_fdinfo_access_allowed(inode);
+
+	if (ret)
+		return ret;
+
 	return single_open(file, seq_show, inode);
 }
 
@@ -348,12 +358,23 @@ static int proc_readfdinfo(struct file *file, struct dir_context *ctx)
 				  proc_fdinfo_instantiate);
 }
 
+static int proc_open_fdinfo(struct inode *inode, struct file *file)
+{
+	int ret = proc_fdinfo_access_allowed(inode);
+
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 const struct inode_operations proc_fdinfo_inode_operations = {
 	.lookup		= proc_lookupfdinfo,
 	.setattr	= proc_setattr,
 };
 
 const struct file_operations proc_fdinfo_operations = {
+	.open		= proc_open_fdinfo,
 	.read		= generic_read_dir,
 	.iterate_shared	= proc_readfdinfo,
 	.llseek		= generic_file_llseek,

mm/huge_memory.c

@@ -2495,11 +2495,16 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
 	struct address_space *mapping = NULL;
 	int extra_pins, ret;
 	pgoff_t end;
+	bool is_hzp;
 
-	VM_BUG_ON_PAGE(is_huge_zero_page(head), head);
 	VM_BUG_ON_PAGE(!PageLocked(head), head);
 	VM_BUG_ON_PAGE(!PageCompound(head), head);
 
+	is_hzp = is_huge_zero_page(head);
+	VM_WARN_ON_ONCE_PAGE(is_hzp, head);
+	if (is_hzp)
+		return -EBUSY;
+
 	if (PageWriteback(head))
 		return -EBUSY;
 

mm/kfence/core.c

@@ -621,6 +621,16 @@ static bool __init kfence_init_pool_early(void)
 	 * fails for the first page, and therefore expect addr==__kfence_pool in
 	 * most failure cases.
 	 */
+	for (char *p = (char *)addr; p < __kfence_pool + KFENCE_POOL_SIZE; p += PAGE_SIZE) {
+		struct slab *slab = virt_to_slab(p);
+
+		if (!slab)
+			continue;
+#ifdef CONFIG_MEMCG
+		slab->memcg_data = 0;
+#endif
+		__folio_clear_slab(slab_folio(slab));
+	}
 	memblock_free_late(__pa(addr), KFENCE_POOL_SIZE - (addr - (unsigned long)__kfence_pool));
 	__kfence_pool = NULL;
 	return false;

mm/memory-failure.c

@@ -1274,7 +1274,7 @@ static int get_any_page(struct page *p, unsigned long flags)
 	}
 out:
 	if (ret == -EIO)
-		dump_page(p, "hwpoison: unhandlable page");
+		pr_err("Memory failure: %#lx: unhandlable page.\n", page_to_pfn(p));
 
 	return ret;
 }
@@ -1860,19 +1860,6 @@ int memory_failure(unsigned long pfn, int flags)
 	}
 
 	if (PageTransHuge(hpage)) {
-		/*
-		 * Bail out before SetPageHasHWPoisoned() if hpage is
-		 * huge_zero_page, although PG_has_hwpoisoned is not
-		 * checked in set_huge_zero_page().
-		 *
-		 * TODO: Handle memory failure of huge_zero_page thoroughly.
-		 */
-		if (is_huge_zero_page(hpage)) {
-			action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED);
-			res = -EBUSY;
-			goto unlock_mutex;
-		}
-
 		/*
 		 * The flag must be set after the refcount is bumped
 		 * otherwise it may race with THP split.