Merge tag 'mm-nonmm-stable-2022-05-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc updates from Andrew Morton:
 "The non-MM patch queue for this merge window.

  Not a lot of material this cycle. Many singleton patches against
  various subsystems. Most notably some maintenance work in ocfs2
  and initramfs"

* tag 'mm-nonmm-stable-2022-05-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (65 commits)
  kcov: update pos before writing pc in trace function
  ocfs2: dlmfs: fix error handling of user_dlm_destroy_lock
  ocfs2: dlmfs: don't clear USER_LOCK_ATTACHED when destroying lock
  fs/ntfs: remove redundant variable idx
  fat: remove time truncations in vfat_create/vfat_mkdir
  fat: report creation time in statx
  fat: ignore ctime updates, and keep ctime identical to mtime in memory
  fat: split fat_truncate_time() into separate functions
  MAINTAINERS: add Muchun as a memcg reviewer
  proc/sysctl: make protected_* world readable
  ia64: mca: drop redundant spinlock initialization
  tty: fix deadlock caused by calling printk() under tty_port->lock
  relay: remove redundant assignment to pointer buf
  fs/ntfs3: validate BOOT sectors_per_clusters
  lib/string_helpers: fix not adding strarray to device's resource list
  kernel/crash_core.c: remove redundant check of ck_cmdline
  ELF, uapi: fixup ELF_ST_TYPE definition
  ipc/mqueue: use get_tree_nodev() in mqueue_get_tree()
  ipc: update semtimedop() to use hrtimer
  ipc/sem: remove redundant assignments
  ...

21 files changed, 97 insertions, 282 deletions

diff --git a/arch/alpha/lib/csum_partial_copy.c b/arch/alpha/lib/csum_partial_copy.c
index 1931a04af85a..4d180d96f09e 100644
--- a/arch/alpha/lib/csum_partial_copy.c
+++ b/arch/alpha/lib/csum_partial_copy.c
@@ -353,7 +353,6 @@ csum_and_copy_from_user(const void __user *src, void *dst, int len)
 		return 0;
 	return __csum_and_copy(src, dst, len);
 }
-EXPORT_SYMBOL(csum_and_copy_from_user);
 
 __wsum
 csum_partial_copy_nocheck(const void *src, void *dst, int len)
diff --git a/arch/arm/kernel/crash_dump.c b/arch/arm/kernel/crash_dump.c
index 53cb92435392..938bd932df9a 100644
--- a/arch/arm/kernel/crash_dump.c
+++ b/arch/arm/kernel/crash_dump.c
@@ -14,22 +14,10 @@
 #include <linux/crash_dump.h>
 #include <linux/uaccess.h>
 #include <linux/io.h>
+#include <linux/uio.h>
 
-/**
- * copy_oldmem_page() - copy one page from old kernel memory
- * @pfn: page frame number to be copied
- * @buf: buffer where the copied page is placed
- * @csize: number of bytes to copy
- * @offset: offset in bytes into the page
- * @userbuf: if set, @buf is int he user address space
- *
- * This function copies one page from old kernel memory into buffer pointed by
- * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes
- * copied or negative error in case of failure.
- */
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
-			 size_t csize, unsigned long offset,
-			 int userbuf)
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
+			 size_t csize, unsigned long offset)
 {
 	void *vaddr;
 
@@ -40,14 +28,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 	if (!vaddr)
 		return -ENOMEM;
 
-	if (userbuf) {
-		if (copy_to_user(buf, vaddr + offset, csize)) {
-			iounmap(vaddr);
-			return -EFAULT;
-		}
-	} else {
-		memcpy(buf, vaddr + offset, csize);
-	}
+	csize = copy_to_iter(vaddr + offset, csize, iter);
 
 	iounmap(vaddr);
 	return csize;
diff --git a/arch/arm64/kernel/crash_dump.c b/arch/arm64/kernel/crash_dump.c
index 58303a9ec32c..670e4ce81822 100644
--- a/arch/arm64/kernel/crash_dump.c
+++ b/arch/arm64/kernel/crash_dump.c
@@ -9,25 +9,11 @@
 #include <linux/crash_dump.h>
 #include <linux/errno.h>
 #include <linux/io.h>
-#include <linux/memblock.h>
-#include <linux/uaccess.h>
+#include <linux/uio.h>
 #include <asm/memory.h>
 
-/**
- * copy_oldmem_page() - copy one page from old kernel memory
- * @pfn: page frame number to be copied
- * @buf: buffer where the copied page is placed
- * @csize: number of bytes to copy
- * @offset: offset in bytes into the page
- * @userbuf: if set, @buf is in a user address space
- *
- * This function copies one page from old kernel memory into buffer pointed by
- * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes
- * copied or negative error in case of failure.
- */
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
-			 size_t csize, unsigned long offset,
-			 int userbuf)
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
+			 size_t csize, unsigned long offset)
 {
 	void *vaddr;
 
@@ -38,14 +24,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 	if (!vaddr)
 		return -ENOMEM;
 
-	if (userbuf) {
-		if (copy_to_user((char __user *)buf, vaddr + offset, csize)) {
-			memunmap(vaddr);
-			return -EFAULT;
-		}
-	} else {
-		memcpy(buf, vaddr + offset, csize);
-	}
+	csize = copy_to_iter(vaddr + offset, csize, iter);
 
 	memunmap(vaddr);
 
diff --git a/arch/ia64/kernel/crash_dump.c b/arch/ia64/kernel/crash_dump.c
index 0ed3c3dee4cd..4ef68e2aa757 100644
--- a/arch/ia64/kernel/crash_dump.c
+++ b/arch/ia64/kernel/crash_dump.c
@@ -10,42 +10,18 @@
 #include <linux/errno.h>
 #include <linux/types.h>
 #include <linux/crash_dump.h>
-
+#include <linux/uio.h>
 #include <asm/page.h>
-#include <linux/uaccess.h>
 
-/**
- * copy_oldmem_page - copy one page from "oldmem"
- * @pfn: page frame number to be copied
- * @buf: target memory address for the copy; this can be in kernel address
- *	space or user address space (see @userbuf)
- * @csize: number of bytes to copy
- * @offset: offset in bytes into the page (based on pfn) to begin the copy
- * @userbuf: if set, @buf is in user address space, use copy_to_user(),
- *	otherwise @buf is in kernel address space, use memcpy().
- *
- * Copy a page from "oldmem". For this page, there is no pte mapped
- * in the current kernel. We stitch up a pte, similar to kmap_atomic.
- *
- * Calling copy_to_user() in atomic context is not desirable. Hence first
- * copying the data to a pre-allocated kernel page and then copying to user
- * space in non-atomic context.
- */
-ssize_t
-copy_oldmem_page(unsigned long pfn, char *buf,
-		size_t csize, unsigned long offset, int userbuf)
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
+		size_t csize, unsigned long offset)
 {
 	void  *vaddr;
 
 	if (!csize)
 		return 0;
 	vaddr = __va(pfn<<PAGE_SHIFT);
-	if (userbuf) {
-		if (copy_to_user(buf, (vaddr + offset), csize)) {
-			return -EFAULT;
-		}
-	} else
-		memcpy(buf, (vaddr + offset), csize);
+	csize = copy_to_iter(vaddr + offset, csize, iter);
 	return csize;
 }
 
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c
index 1a7bab1c5d7c..ca34e51e84b4 100644
--- a/arch/ia64/kernel/kprobes.c
+++ b/arch/ia64/kernel/kprobes.c
@@ -29,38 +29,38 @@ struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}};
 
 enum instruction_type {A, I, M, F, B, L, X, u};
 static enum instruction_type bundle_encoding[32][3] = {
-  { M, I, I },				/* 00 */
-  { M, I, I },				/* 01 */
-  { M, I, I },				/* 02 */
-  { M, I, I },				/* 03 */
-  { M, L, X },				/* 04 */
-  { M, L, X },				/* 05 */
-  { u, u, u },  			/* 06 */
-  { u, u, u },  			/* 07 */
-  { M, M, I },				/* 08 */
-  { M, M, I },				/* 09 */
-  { M, M, I },				/* 0A */
-  { M, M, I },				/* 0B */
-  { M, F, I },				/* 0C */
-  { M, F, I },				/* 0D */
-  { M, M, F },				/* 0E */
-  { M, M, F },				/* 0F */
-  { M, I, B },				/* 10 */
-  { M, I, B },				/* 11 */
-  { M, B, B },				/* 12 */
-  { M, B, B },				/* 13 */
-  { u, u, u },  			/* 14 */
-  { u, u, u },  			/* 15 */
-  { B, B, B },				/* 16 */
-  { B, B, B },				/* 17 */
-  { M, M, B },				/* 18 */
-  { M, M, B },				/* 19 */
-  { u, u, u },  			/* 1A */
-  { u, u, u },  			/* 1B */
-  { M, F, B },				/* 1C */
-  { M, F, B },				/* 1D */
-  { u, u, u },  			/* 1E */
-  { u, u, u },  			/* 1F */
+	[0x00] = { M, I, I },
+	[0x01] = { M, I, I },
+	[0x02] = { M, I, I },
+	[0x03] = { M, I, I },
+	[0x04] = { M, L, X },
+	[0x05] = { M, L, X },
+	[0x06] = { u, u, u },
+	[0x07] = { u, u, u },
+	[0x08] = { M, M, I },
+	[0x09] = { M, M, I },
+	[0x0A] = { M, M, I },
+	[0x0B] = { M, M, I },
+	[0x0C] = { M, F, I },
+	[0x0D] = { M, F, I },
+	[0x0E] = { M, M, F },
+	[0x0F] = { M, M, F },
+	[0x10] = { M, I, B },
+	[0x11] = { M, I, B },
+	[0x12] = { M, B, B },
+	[0x13] = { M, B, B },
+	[0x14] = { u, u, u },
+	[0x15] = { u, u, u },
+	[0x16] = { B, B, B },
+	[0x17] = { B, B, B },
+	[0x18] = { M, M, B },
+	[0x19] = { M, M, B },
+	[0x1A] = { u, u, u },
+	[0x1B] = { u, u, u },
+	[0x1C] = { M, F, B },
+	[0x1D] = { M, F, B },
+	[0x1E] = { u, u, u },
+	[0x1F] = { u, u, u },
 };
 
 /* Insert a long branch code */
diff --git a/arch/ia64/kernel/mca.c b/arch/ia64/kernel/mca.c
index e628a88607bb..c62a66710ad6 100644
--- a/arch/ia64/kernel/mca.c
+++ b/arch/ia64/kernel/mca.c
@@ -290,7 +290,6 @@ static void ia64_mlogbuf_finish(int wait)
 {
 	BREAK_LOGLEVEL(console_loglevel);
 
-	spin_lock_init(&mlogbuf_rlock);
 	ia64_mlogbuf_dump();
 	printk(KERN_EMERG "mlogbuf_finish: printing switched to urgent mode, "
 		"MCA/INIT might be dodgy or fail.\n");
diff --git a/arch/ia64/kernel/palinfo.c b/arch/ia64/kernel/palinfo.c
index 64189f04c1a4..b9ae093bfe37 100644
--- a/arch/ia64/kernel/palinfo.c
+++ b/arch/ia64/kernel/palinfo.c
@@ -120,7 +120,7 @@ static const char *mem_attrib[]={
  * Input:
  *	- a pointer to a buffer to hold the string
  *	- a 64-bit vector
- * Ouput:
+ * Output:
  *	- a pointer to the end of the buffer
  *
  */
diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c
index a19acd9f5e1f..4fc6e38a8459 100644
--- a/arch/ia64/kernel/ptrace.c
+++ b/arch/ia64/kernel/ptrace.c
@@ -2025,7 +2025,7 @@ static void syscall_get_args_cb(struct unw_frame_info *info, void *data)
 	 * - epsinstruction: cfm is set by br.call
 	 *   locals don't exist.
 	 *
-	 * For both cases argguments are reachable in cfm.sof - cfm.sol.
+	 * For both cases arguments are reachable in cfm.sof - cfm.sol.
 	 * CFM: [ ... | sor: 17..14 | sol : 13..7 | sof : 6..0 ]
 	 */
 	cfm = pt->cr_ifs;
diff --git a/arch/ia64/kernel/traps.c b/arch/ia64/kernel/traps.c
index 753642366e12..53735b1d1be3 100644
--- a/arch/ia64/kernel/traps.c
+++ b/arch/ia64/kernel/traps.c
@@ -309,7 +309,7 @@ handle_fpu_swa (int fp_fault, struct pt_regs *regs, unsigned long isr)
 			/*
 			 * Lower 4 bits are used as a count. Upper bits are a sequence
 			 * number that is updated when count is reset. The cmpxchg will
-			 * fail is seqno has changed. This minimizes mutiple cpus
+			 * fail is seqno has changed. This minimizes multiple cpus
 			 * resetting the count.
 			 */
 			if (current_jiffies > last.time)
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 3c3e15b22608..855d949d81df 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -449,7 +449,7 @@ mem_init (void)
 	memblock_free_all();
 
 	/*
-	 * For fsyscall entrpoints with no light-weight handler, use the ordinary
+	 * For fsyscall entrypoints with no light-weight handler, use the ordinary
 	 * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
 	 * code can tell them apart.
 	 */
diff --git a/arch/ia64/mm/tlb.c b/arch/ia64/mm/tlb.c
index 135b5135cace..ca060e7a2a46 100644
--- a/arch/ia64/mm/tlb.c
+++ b/arch/ia64/mm/tlb.c
@@ -174,7 +174,7 @@ __setup("nptcg=", set_nptcg);
  * override table (in which case we should ignore the value from
  * PAL_VM_SUMMARY).
  *
- * Kernel parameter "nptcg=" overrides maximum number of simultanesous ptc.g
+ * Kernel parameter "nptcg=" overrides maximum number of simultaneous ptc.g
  * purges defined in either PAL_VM_SUMMARY or PAL override table. In this case,
  * we should ignore the value from either PAL_VM_SUMMARY or PAL override table.
  *
@@ -516,7 +516,7 @@ found:
 	if (i >= per_cpu(ia64_tr_num, cpu))
 		return -EBUSY;
 
-	/*Record tr info for mca hander use!*/
+	/*Record tr info for mca handler use!*/
 	if (i > per_cpu(ia64_tr_used, cpu))
 		per_cpu(ia64_tr_used, cpu) = i;
 
diff --git a/arch/m68k/lib/checksum.c b/arch/m68k/lib/checksum.c
index 7e6afeae6217..5acb821849d3 100644
--- a/arch/m68k/lib/checksum.c
+++ b/arch/m68k/lib/checksum.c
@@ -265,8 +265,6 @@ csum_and_copy_from_user(const void __user *src, void *dst, int len)
 	return sum;
 }
 
-EXPORT_SYMBOL(csum_and_copy_from_user);
-
 
 /*
  * copy from kernel space while checksumming, otherwise like csum_partial
diff --git a/arch/mips/kernel/crash_dump.c b/arch/mips/kernel/crash_dump.c
index 2e50f55185a6..6e50f4902409 100644
--- a/arch/mips/kernel/crash_dump.c
+++ b/arch/mips/kernel/crash_dump.c
@@ -1,22 +1,10 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <linux/highmem.h>
 #include <linux/crash_dump.h>
+#include <linux/uio.h>
 
-/**
- * copy_oldmem_page - copy one page from "oldmem"
- * @pfn: page frame number to be copied
- * @buf: target memory address for the copy; this can be in kernel address
- *	space or user address space (see @userbuf)
- * @csize: number of bytes to copy
- * @offset: offset in bytes into the page (based on pfn) to begin the copy
- * @userbuf: if set, @buf is in user address space, use copy_to_user(),
- *	otherwise @buf is in kernel address space, use memcpy().
- *
- * Copy a page from "oldmem". For this page, there is no pte mapped
- * in the current kernel.
- */
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
-			 size_t csize, unsigned long offset, int userbuf)
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
+			 size_t csize, unsigned long offset)
 {
 	void  *vaddr;
 
@@ -24,14 +12,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 		return 0;
 
 	vaddr = kmap_local_pfn(pfn);
-
-	if (!userbuf) {
-		memcpy(buf, vaddr + offset, csize);
-	} else {
-		if (copy_to_user(buf, vaddr + offset, csize))
-			csize = -EFAULT;
-	}
-
+	csize = copy_to_iter(vaddr + offset, csize, iter);
 	kunmap_local(vaddr);
 
 	return csize;
diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c
index 5693e1c67c2b..32b4a97f1b79 100644
--- a/arch/powerpc/kernel/crash_dump.c
+++ b/arch/powerpc/kernel/crash_dump.c
@@ -16,7 +16,7 @@
 #include <asm/kdump.h>
 #include <asm/prom.h>
 #include <asm/firmware.h>
-#include <linux/uaccess.h>
+#include <linux/uio.h>
 #include <asm/rtas.h>
 #include <asm/inst.h>
 
@@ -68,33 +68,8 @@ void __init setup_kdump_trampoline(void)
 }
 #endif /* CONFIG_NONSTATIC_KERNEL */
 
-static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize,
-                               unsigned long offset, int userbuf)
-{
-	if (userbuf) {
-		if (copy_to_user((char __user *)buf, (vaddr + offset), csize))
-			return -EFAULT;
-	} else
-		memcpy(buf, (vaddr + offset), csize);
-
-	return csize;
-}
-
-/**
- * copy_oldmem_page - copy one page from "oldmem"
- * @pfn: page frame number to be copied
- * @buf: target memory address for the copy; this can be in kernel address
- *      space or user address space (see @userbuf)
- * @csize: number of bytes to copy
- * @offset: offset in bytes into the page (based on pfn) to begin the copy
- * @userbuf: if set, @buf is in user address space, use copy_to_user(),
- *      otherwise @buf is in kernel address space, use memcpy().
- *
- * Copy a page from "oldmem". For this page, there is no pte mapped
- * in the current kernel. We stitch up a pte, similar to kmap_atomic.
- */
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
-			size_t csize, unsigned long offset, int userbuf)
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
+			size_t csize, unsigned long offset)
 {
 	void  *vaddr;
 	phys_addr_t paddr;
@@ -107,10 +82,10 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 
 	if (memblock_is_region_memory(paddr, csize)) {
 		vaddr = __va(paddr);
-		csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf);
+		csize = copy_to_iter(vaddr + offset, csize, iter);
 	} else {
 		vaddr = ioremap_cache(paddr, PAGE_SIZE);
-		csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf);
+		csize = copy_to_iter(vaddr + offset, csize, iter);
 		iounmap(vaddr);
 	}
 
diff --git a/arch/powerpc/lib/checksum_wrappers.c b/arch/powerpc/lib/checksum_wrappers.c
index f3999cbb2fcc..1a14c8780278 100644
--- a/arch/powerpc/lib/checksum_wrappers.c
+++ b/arch/powerpc/lib/checksum_wrappers.c
@@ -24,7 +24,6 @@ __wsum csum_and_copy_from_user(const void __user *src, void *dst,
 	user_read_access_end();
 	return csum;
 }
-EXPORT_SYMBOL(csum_and_copy_from_user);
 
 __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)
 {
@@ -38,4 +37,3 @@ __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)
 	user_write_access_end();
 	return csum;
 }
-EXPORT_SYMBOL(csum_and_copy_to_user);
diff --git a/arch/riscv/kernel/crash_dump.c b/arch/riscv/kernel/crash_dump.c
index 86cc0ada5752..ea2158cee97b 100644
--- a/arch/riscv/kernel/crash_dump.c
+++ b/arch/riscv/kernel/crash_dump.c
@@ -7,22 +7,10 @@
 
 #include <linux/crash_dump.h>
 #include <linux/io.h>
+#include <linux/uio.h>
 
-/**
- * copy_oldmem_page() - copy one page from old kernel memory
- * @pfn: page frame number to be copied
- * @buf: buffer where the copied page is placed
- * @csize: number of bytes to copy
- * @offset: offset in bytes into the page
- * @userbuf: if set, @buf is in a user address space
- *
- * This function copies one page from old kernel memory into buffer pointed by
- * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes
- * copied or negative error in case of failure.
- */
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
-			 size_t csize, unsigned long offset,
-			 int userbuf)
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
+			 size_t csize, unsigned long offset)
 {
 	void *vaddr;
 
@@ -33,13 +21,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 	if (!vaddr)
 		return -ENOMEM;
 
-	if (userbuf) {
-		if (copy_to_user((char __user *)buf, vaddr + offset, csize)) {
-			memunmap(vaddr);
-			return -EFAULT;
-		}
-	} else
-		memcpy(buf, vaddr + offset, csize);
+	csize = copy_to_iter(vaddr + offset, csize, iter);
 
 	memunmap(vaddr);
 	return csize;
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index 69819b765250..a2c1c55daec0 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/memblock.h>
 #include <linux/elf.h>
+#include <linux/uio.h>
 #include <asm/asm-offsets.h>
 #include <asm/os_info.h>
 #include <asm/elf.h>
@@ -212,8 +213,8 @@ static int copy_oldmem_user(void __user *dst, unsigned long src, size_t count)
 /*
  * Copy one page from "oldmem"
  */
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
-			 unsigned long offset, int userbuf)
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize,
+			 unsigned long offset)
 {
 	unsigned long src;
 	int rc;
@@ -221,10 +222,12 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
 	if (!csize)
 		return 0;
 	src = pfn_to_phys(pfn) + offset;
-	if (userbuf)
-		rc = copy_oldmem_user((void __force __user *) buf, src, csize);
+
+	/* XXX: pass the iov_iter down to a common function */
+	if (iter_is_iovec(iter))
+		rc = copy_oldmem_user(iter->iov->iov_base, src, csize);
 	else
-		rc = copy_oldmem_kernel((void *) buf, src, csize);
+		rc = copy_oldmem_kernel(iter->kvec->iov_base, src, csize);
 	return rc;
 }
 
diff --git a/arch/sh/kernel/crash_dump.c b/arch/sh/kernel/crash_dump.c
index 5b41b59698c1..19ce6a950aac 100644
--- a/arch/sh/kernel/crash_dump.c
+++ b/arch/sh/kernel/crash_dump.c
@@ -8,23 +8,11 @@
 #include <linux/errno.h>
 #include <linux/crash_dump.h>
 #include <linux/io.h>
+#include <linux/uio.h>
 #include <linux/uaccess.h>
 
-/**
- * copy_oldmem_page - copy one page from "oldmem"
- * @pfn: page frame number to be copied
- * @buf: target memory address for the copy; this can be in kernel address
- *	space or user address space (see @userbuf)
- * @csize: number of bytes to copy
- * @offset: offset in bytes into the page (based on pfn) to begin the copy
- * @userbuf: if set, @buf is in user address space, use copy_to_user(),
- *	otherwise @buf is in kernel address space, use memcpy().
- *
- * Copy a page from "oldmem". For this page, there is no pte mapped
- * in the current kernel. We stitch up a pte, similar to kmap_atomic.
- */
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
-                               size_t csize, unsigned long offset, int userbuf)
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
+			 size_t csize, unsigned long offset)
 {
 	void  __iomem *vaddr;
 
@@ -32,15 +20,8 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 		return 0;
 
 	vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);
-
-	if (userbuf) {
-		if (copy_to_user((void __user *)buf, (vaddr + offset), csize)) {
-			iounmap(vaddr);
-			return -EFAULT;
-		}
-	} else
-	memcpy(buf, (vaddr + offset), csize);
-
+	csize = copy_to_iter(vaddr + offset, csize, iter);
 	iounmap(vaddr);
+
 	return csize;
 }
diff --git a/arch/x86/kernel/crash_dump_32.c b/arch/x86/kernel/crash_dump_32.c
index 5fcac46aaf6b..5f4ae5476e19 100644
--- a/arch/x86/kernel/crash_dump_32.c
+++ b/arch/x86/kernel/crash_dump_32.c
@@ -10,8 +10,7 @@
 #include <linux/errno.h>
 #include <linux/highmem.h>
 #include <linux/crash_dump.h>
-
-#include <linux/uaccess.h>
+#include <linux/uio.h>
 
 static inline bool is_crashed_pfn_valid(unsigned long pfn)
 {
@@ -29,21 +28,8 @@ static inline bool is_crashed_pfn_valid(unsigned long pfn)
 #endif
 }
 
-/**
- * copy_oldmem_page - copy one page from "oldmem"
- * @pfn: page frame number to be copied
- * @buf: target memory address for the copy; this can be in kernel address
- *	space or user address space (see @userbuf)
- * @csize: number of bytes to copy
- * @offset: offset in bytes into the page (based on pfn) to begin the copy
- * @userbuf: if set, @buf is in user address space, use copy_to_user(),
- *	otherwise @buf is in kernel address space, use memcpy().
- *
- * Copy a page from "oldmem". For this page, there might be no pte mapped
- * in the current kernel.
- */
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
-			 unsigned long offset, int userbuf)
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize,
+			 unsigned long offset)
 {
 	void  *vaddr;
 
@@ -54,14 +40,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
 		return -EFAULT;
 
 	vaddr = kmap_local_pfn(pfn);
-
-	if (!userbuf) {
-		memcpy(buf, vaddr + offset, csize);
-	} else {
-		if (copy_to_user(buf, vaddr + offset, csize))
-			csize = -EFAULT;
-	}
-
+	csize = copy_to_iter(vaddr + offset, csize, iter);
 	kunmap_local(vaddr);
 
 	return csize;
diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index 97529552dd24..e75bc2f217ff 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -8,12 +8,12 @@
 
 #include <linux/errno.h>
 #include <linux/crash_dump.h>
-#include <linux/uaccess.h>
+#include <linux/uio.h>
 #include <linux/io.h>
 #include <linux/cc_platform.h>
 
-static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
-				  unsigned long offset, int userbuf,
+static ssize_t __copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
+				  size_t csize, unsigned long offset,
 				  bool encrypted)
 {
 	void  *vaddr;
@@ -29,50 +29,36 @@ static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
 	if (!vaddr)
 		return -ENOMEM;
 
-	if (userbuf) {
-		if (copy_to_user((void __user *)buf, vaddr + offset, csize)) {
-			iounmap((void __iomem *)vaddr);
-			return -EFAULT;
-		}
-	} else
-		memcpy(buf, vaddr + offset, csize);
+	csize = copy_to_iter(vaddr + offset, csize, iter);
 
 	iounmap((void __iomem *)vaddr);
 	return csize;
 }
 
-/**
- * copy_oldmem_page - copy one page of memory
- * @pfn: page frame number to be copied
- * @buf: target memory address for the copy; this can be in kernel address
- *	space or user address space (see @userbuf)
- * @csize: number of bytes to copy
- * @offset: offset in bytes into the page (based on pfn) to begin the copy
- * @userbuf: if set, @buf is in user address space, use copy_to_user(),
- *	otherwise @buf is in kernel address space, use memcpy().
- *
- * Copy a page from the old kernel's memory. For this page, there is no pte
- * mapped in the current kernel. We stitch up a pte, similar to kmap_atomic.
- */
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
-			 unsigned long offset, int userbuf)
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize,
+			 unsigned long offset)
 {
-	return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, false);
+	return __copy_oldmem_page(iter, pfn, csize, offset, false);
 }
 
-/**
+/*
  * copy_oldmem_page_encrypted - same as copy_oldmem_page() above but ioremap the
  * memory with the encryption mask set to accommodate kdump on SME-enabled
  * machines.
  */
-ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
-				   unsigned long offset, int userbuf)
+ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter, unsigned long pfn,
+				   size_t csize, unsigned long offset)
 {
-	return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true);
+	return __copy_oldmem_page(iter, pfn, csize, offset, true);
 }
 
 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
 {
-	return read_from_oldmem(buf, count, ppos, 0,
+	struct kvec kvec = { .iov_base = buf, .iov_len = count };
+	struct iov_iter iter;
+
+	iov_iter_kvec(&iter, READ, &kvec, 1, count);
+
+	return read_from_oldmem(&iter, count, ppos,
 				cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT));
 }
diff --git a/arch/x86/lib/csum-wrappers_64.c b/arch/x86/lib/csum-wrappers_64.c
index 189344924a2b..145f9a0bde29 100644
--- a/arch/x86/lib/csum-wrappers_64.c
+++ b/arch/x86/lib/csum-wrappers_64.c
@@ -32,7 +32,6 @@ csum_and_copy_from_user(const void __user *src, void *dst, int len)
 	user_access_end();
 	return sum;
 }
-EXPORT_SYMBOL(csum_and_copy_from_user);
 
 /**
  * csum_and_copy_to_user - Copy and checksum to user space.
@@ -57,7 +56,6 @@ csum_and_copy_to_user(const void *src, void __user *dst, int len)
 	user_access_end();
 	return sum;
 }
-EXPORT_SYMBOL(csum_and_copy_to_user);
 
 /**
  * csum_partial_copy_nocheck - Copy and checksum.