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From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, david@redhat.com,
	gregkh@linuxfoundation.org, hdanton@sina.com,
	huang.ying.caritas@gmail.com, linux-mm@kvack.org,
	mhocko@suse.com, minchan@kernel.org, mm-commits@vger.kernel.org,
	oleksiy.avramchenko@sonymobile.com, rostedt@goodmis.org,
	torvalds@linux-foundation.org, willy@infradead.org
Subject: [patch 76/91] mm/vmalloc: remove vwrite()
Date: Thu, 06 May 2021 18:06:06 -0700	[thread overview]
Message-ID: <20210507010606.NS9JjpNt_%akpm@linux-foundation.org> (raw)
In-Reply-To: <20210506180126.03e1baee7ca52bedb6cc6003@linux-foundation.org>

From: David Hildenbrand <david@redhat.com>
Subject: mm/vmalloc: remove vwrite()

The last user (/dev/kmem) is gone. Let's drop it.

Link: https://lkml.kernel.org/r/20210324102351.6932-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: huang ying <huang.ying.caritas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/vmalloc.h |    1 
 mm/nommu.c              |   10 ---
 mm/vmalloc.c            |  116 --------------------------------------
 3 files changed, 1 insertion(+), 126 deletions(-)

--- a/include/linux/vmalloc.h~mm-vmalloc-remove-vwrite
+++ a/include/linux/vmalloc.h
@@ -229,7 +229,6 @@ static inline void set_vm_flush_reset_pe
 
 /* for /proc/kcore */
 extern long vread(char *buf, char *addr, unsigned long count);
-extern long vwrite(char *buf, char *addr, unsigned long count);
 
 /*
  *	Internals.  Dont't use..
--- a/mm/nommu.c~mm-vmalloc-remove-vwrite
+++ a/mm/nommu.c
@@ -210,16 +210,6 @@ long vread(char *buf, char *addr, unsign
 	return count;
 }
 
-long vwrite(char *buf, char *addr, unsigned long count)
-{
-	/* Don't allow overflow */
-	if ((unsigned long) addr + count < count)
-		count = -(unsigned long) addr;
-
-	memcpy(addr, buf, count);
-	return count;
-}
-
 /*
  *	vmalloc  -  allocate virtually contiguous memory
  *
--- a/mm/vmalloc.c~mm-vmalloc-remove-vwrite
+++ a/mm/vmalloc.c
@@ -3146,10 +3146,7 @@ static int aligned_vread(char *buf, char
 		 * kmap() and get small overhead in this access function.
 		 */
 		if (p) {
-			/*
-			 * we can expect USER0 is not used (see vread/vwrite's
-			 * function description)
-			 */
+			/* We can expect USER0 is not used -- see vread() */
 			void *map = kmap_atomic(p);
 			memcpy(buf, map + offset, length);
 			kunmap_atomic(map);
@@ -3164,43 +3161,6 @@ static int aligned_vread(char *buf, char
 	return copied;
 }
 
-static int aligned_vwrite(char *buf, char *addr, unsigned long count)
-{
-	struct page *p;
-	int copied = 0;
-
-	while (count) {
-		unsigned long offset, length;
-
-		offset = offset_in_page(addr);
-		length = PAGE_SIZE - offset;
-		if (length > count)
-			length = count;
-		p = vmalloc_to_page(addr);
-		/*
-		 * To do safe access to this _mapped_ area, we need
-		 * lock. But adding lock here means that we need to add
-		 * overhead of vmalloc()/vfree() calles for this _debug_
-		 * interface, rarely used. Instead of that, we'll use
-		 * kmap() and get small overhead in this access function.
-		 */
-		if (p) {
-			/*
-			 * we can expect USER0 is not used (see vread/vwrite's
-			 * function description)
-			 */
-			void *map = kmap_atomic(p);
-			memcpy(map + offset, buf, length);
-			kunmap_atomic(map);
-		}
-		addr += length;
-		buf += length;
-		copied += length;
-		count -= length;
-	}
-	return copied;
-}
-
 /**
  * vread() - read vmalloc area in a safe way.
  * @buf:     buffer for reading data
@@ -3283,80 +3243,6 @@ finished:
 	return buflen;
 }
 
-/**
- * vwrite() - write vmalloc area in a safe way.
- * @buf:      buffer for source data
- * @addr:     vm address.
- * @count:    number of bytes to be read.
- *
- * This function checks that addr is a valid vmalloc'ed area, and
- * copy data from a buffer to the given addr. If specified range of
- * [addr...addr+count) includes some valid address, data is copied from
- * proper area of @buf. If there are memory holes, no copy to hole.
- * IOREMAP area is treated as memory hole and no copy is done.
- *
- * If [addr...addr+count) doesn't includes any intersects with alive
- * vm_struct area, returns 0. @buf should be kernel's buffer.
- *
- * Note: In usual ops, vwrite() is never necessary because the caller
- * should know vmalloc() area is valid and can use memcpy().
- * This is for routines which have to access vmalloc area without
- * any information, as /dev/kmem.
- *
- * Return: number of bytes for which addr and buf should be
- * increased (same number as @count) or %0 if [addr...addr+count)
- * doesn't include any intersection with valid vmalloc area
- */
-long vwrite(char *buf, char *addr, unsigned long count)
-{
-	struct vmap_area *va;
-	struct vm_struct *vm;
-	char *vaddr;
-	unsigned long n, buflen;
-	int copied = 0;
-
-	/* Don't allow overflow */
-	if ((unsigned long) addr + count < count)
-		count = -(unsigned long) addr;
-	buflen = count;
-
-	spin_lock(&vmap_area_lock);
-	list_for_each_entry(va, &vmap_area_list, list) {
-		if (!count)
-			break;
-
-		if (!va->vm)
-			continue;
-
-		vm = va->vm;
-		vaddr = (char *) vm->addr;
-		if (addr >= vaddr + get_vm_area_size(vm))
-			continue;
-		while (addr < vaddr) {
-			if (count == 0)
-				goto finished;
-			buf++;
-			addr++;
-			count--;
-		}
-		n = vaddr + get_vm_area_size(vm) - addr;
-		if (n > count)
-			n = count;
-		if (!(vm->flags & VM_IOREMAP)) {
-			aligned_vwrite(buf, addr, n);
-			copied++;
-		}
-		buf += n;
-		addr += n;
-		count -= n;
-	}
-finished:
-	spin_unlock(&vmap_area_lock);
-	if (!copied)
-		return 0;
-	return buflen;
-}
-
 /**
  * remap_vmalloc_range_partial - map vmalloc pages to userspace
  * @vma:		vma to cover
_

  parent reply	other threads:[~2021-05-07  1:06 UTC|newest]

Thread overview: 119+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-07  1:01 incoming Andrew Morton
2021-05-07  1:02 ` [patch 01/91] alpha: eliminate old-style function definitions Andrew Morton
2021-05-07  1:02 ` [patch 02/91] alpha: csum_partial_copy.c: add function prototypes from <net/checksum.h> Andrew Morton
2021-05-07  1:02 ` [patch 03/91] fs/proc/generic.c: fix incorrect pde_is_permanent check Andrew Morton
2021-05-07  1:02 ` [patch 04/91] proc: save LOC in __xlate_proc_name() Andrew Morton
2021-05-07  2:24   ` Linus Torvalds
2021-05-07  1:02 ` [patch 05/91] proc: mandate ->proc_lseek in "struct proc_ops" Andrew Morton
2021-05-07  1:02 ` [patch 06/91] proc: delete redundant subset=pid check Andrew Morton
2021-05-07  1:02 ` [patch 07/91] selftests: proc: test subset=pid Andrew Morton
2021-05-07  1:02 ` [patch 08/91] proc/sysctl: fix function name error in comments Andrew Morton
2021-05-07  1:02 ` [patch 09/91] include: remove pagemap.h from blkdev.h Andrew Morton
2021-05-07  1:02 ` [patch 10/91] kernel.h: drop inclusion in bitmap.h Andrew Morton
2021-05-07  1:02 ` [patch 11/91] linux/profile.h: remove unnecessary declaration Andrew Morton
2021-05-07  1:02 ` [patch 12/91] kernel/async.c: fix pr_debug statement Andrew Morton
2021-05-07  1:02 ` [patch 13/91] kernel/cred.c: make init_groups static Andrew Morton
2021-05-07  1:02 ` [patch 14/91] tools: disable -Wno-type-limits Andrew Morton
2021-05-07  1:02 ` [patch 15/91] tools: bitmap: sync function declarations with the kernel Andrew Morton
2021-05-07  1:02 ` [patch 16/91] tools: sync BITMAP_LAST_WORD_MASK() macro " Andrew Morton
2021-05-07  1:02 ` [patch 17/91] arch: rearrange headers inclusion order in asm/bitops for m68k, sh and h8300 Andrew Morton
2021-05-07  1:02 ` [patch 18/91] lib: extend the scope of small_const_nbits() macro Andrew Morton
2021-05-07  1:03 ` [patch 19/91] tools: sync small_const_nbits() macro with the kernel Andrew Morton
2021-05-07  1:03 ` [patch 20/91] lib: inline _find_next_bit() wrappers Andrew Morton
2021-05-07  1:03 ` [patch 21/91] tools: sync find_next_bit implementation Andrew Morton
2021-05-07  1:03 ` [patch 22/91] lib: add fast path for find_next_*_bit() Andrew Morton
2021-05-07  1:03 ` [patch 23/91] lib: add fast path for find_first_*_bit() and find_last_bit() Andrew Morton
2021-05-07  1:03 ` [patch 24/91] tools: sync lib/find_bit implementation Andrew Morton
2021-05-07  1:03 ` [patch 25/91] MAINTAINERS: add entry for the bitmap API Andrew Morton
2021-05-07  1:03 ` [patch 26/91] lib/bch.c: fix a typo in the file bch.c Andrew Morton
2021-05-07  1:03 ` [patch 27/91] lib: fix inconsistent indenting in process_bit1() Andrew Morton
2021-05-07  1:03 ` [patch 28/91] lib/list_sort.c: fix typo in function description Andrew Morton
2021-05-07  1:03 ` [patch 29/91] lib/genalloc.c: fix a typo Andrew Morton
2021-05-07  1:03 ` [patch 30/91] lib: crc8: pointer to data block should be const Andrew Morton
2021-05-07  1:03 ` [patch 31/91] lib: stackdepot: turn depot_lock spinlock to raw_spinlock Andrew Morton
2021-05-07  1:03 ` [patch 32/91] lib/percpu_counter: tame kernel-doc compile warning Andrew Morton
2021-05-07  1:03 ` [patch 33/91] lib/genalloc: add parameter description to fix doc " Andrew Morton
2021-05-07  1:03 ` [patch 34/91] lib: parser: clean up kernel-doc Andrew Morton
2021-05-07  1:03 ` [patch 35/91] include/linux/compat.h: remove unneeded declaration from COMPAT_SYSCALL_DEFINEx() Andrew Morton
2021-05-07  1:03 ` [patch 36/91] checkpatch: warn when missing newline in return sysfs_emit() formats Andrew Morton
2021-05-07  1:03 ` [patch 37/91] checkpatch: exclude four preprocessor sub-expressions from MACRO_ARG_REUSE Andrew Morton
2021-05-07  1:04 ` [patch 38/91] checkpatch: improve ALLOC_ARRAY_ARGS test Andrew Morton
2021-05-07  1:04 ` [patch 39/91] kselftest: introduce new epoll test case Andrew Morton
2021-05-07  1:04 ` [patch 40/91] fs/epoll: restore waking from ep_done_scan() Andrew Morton
2021-05-07  1:04 ` [patch 41/91] isofs: fix fall-through warnings for Clang Andrew Morton
2021-05-07  1:04 ` [patch 42/91] fs/nilfs2: fix misspellings using codespell tool Andrew Morton
2021-05-07  1:04 ` [patch 43/91] nilfs2: fix typos in comments Andrew Morton
2021-05-07  1:04 ` [patch 44/91] hpfs: replace one-element array with flexible-array member Andrew Morton
2021-05-07  1:04 ` [patch 45/91] do_wait: make PIDTYPE_PID case O(1) instead of O(n) Andrew Morton
2021-05-07  1:04 ` [patch 46/91] kernel/fork.c: simplify copy_mm() Andrew Morton
2021-05-07  1:04 ` [patch 47/91] kernel/fork.c: fix typos Andrew Morton
2021-05-07  1:04 ` [patch 48/91] kernel/crash_core: add crashkernel=auto for vmcore creation Andrew Morton
2021-05-07  7:25   ` Linus Torvalds
2021-05-08  3:13     ` Baoquan He
2021-05-08  3:29       ` Baoquan He
2021-05-07  8:16   ` David Hildenbrand
2021-05-08  8:51     ` Baoquan He
2021-05-08  9:22       ` David Hildenbrand
2021-05-10  4:53         ` Baoquan He
2021-05-10  8:32           ` David Hildenbrand
2021-05-10 10:43             ` Baoquan He
2021-05-10 11:01               ` David Hildenbrand
2021-05-10 11:44                 ` Dave Young
2021-05-10 11:56                   ` David Hildenbrand
2021-05-11 13:36                     ` Baoquan He
2021-05-11 16:31                       ` Mike Rapoport
2021-05-11 17:07                         ` David Hildenbrand
2021-05-12 14:51                           ` Baoquan He
2021-05-12 15:07                             ` David Hildenbrand
2021-05-13  5:04                               ` Baoquan He
2021-05-12 19:03                             ` Kairui Song
2021-05-17  8:22                             ` David Hildenbrand
2021-05-18  8:49                               ` Baoquan He
2021-05-18  8:51                                 ` David Hildenbrand
2021-05-18  9:24                                   ` Dave Young
2021-05-12 14:13                         ` Baoquan He
2021-05-12  7:42                     ` Dave Young
2021-05-07  1:04 ` [patch 49/91] kexec: add kexec reboot string Andrew Morton
2021-05-07  1:04 ` [patch 50/91] kernel: kexec_file: fix error return code of kexec_calculate_store_digests() Andrew Morton
2021-05-07  1:04 ` [patch 51/91] kexec: dump kmessage before machine_kexec Andrew Morton
2021-05-07  1:04 ` [patch 52/91] gcov: combine common code Andrew Morton
2021-05-07  1:04 ` [patch 53/91] gcov: simplify buffer allocation Andrew Morton
2021-05-07  1:04 ` [patch 54/91] gcov: use kvmalloc() Andrew Morton
2021-05-07  1:04 ` [patch 55/91] gcov: clang: drop support for clang-10 and older Andrew Morton
2021-05-07  1:04 ` [patch 56/91] smp: kernel/panic.c - silence warnings Andrew Morton
2021-05-07  1:05 ` [patch 57/91] delayacct: clear right task's flag after blkio completes Andrew Morton
2021-05-07  1:05 ` [patch 58/91] gdb: lx-symbols: store the abspath() Andrew Morton
2021-05-07  1:05 ` [patch 59/91] scripts/gdb: document lx_current is only supported by x86 Andrew Morton
2021-05-07  1:05 ` [patch 60/91] scripts/gdb: add lx_current support for arm64 Andrew Morton
2021-05-07  1:05 ` [patch 61/91] kernel/resource: make walk_system_ram_res() find all busy IORESOURCE_SYSTEM_RAM resources Andrew Morton
2021-05-07  1:05 ` [patch 62/91] kernel/resource: make walk_mem_res() find all busy IORESOURCE_MEM resources Andrew Morton
2021-05-07  1:05 ` [patch 63/91] kernel/resource: remove first_lvl / siblings_only logic Andrew Morton
2021-05-07  1:05 ` [patch 64/91] kernel/resource: allow region_intersects users to hold resource_lock Andrew Morton
2021-05-07  1:05 ` [patch 65/91] kernel/resource: refactor __request_region to allow external locking Andrew Morton
2021-05-07  1:05 ` [patch 66/91] kernel/resource: fix locking in request_free_mem_region Andrew Morton
2021-05-07  1:05 ` [patch 67/91] selftests: remove duplicate include Andrew Morton
2021-05-07  1:05 ` [patch 68/91] kernel/async.c: stop guarding pr_debug() statements Andrew Morton
2021-05-07  1:05 ` [patch 69/91] kernel/async.c: remove async_unregister_domain() Andrew Morton
2021-05-07  1:05 ` [patch 70/91] init/initramfs.c: do unpacking asynchronously Andrew Morton
2021-05-07  1:05 ` [patch 71/91] modules: add CONFIG_MODPROBE_PATH Andrew Morton
2021-05-07  1:05 ` [patch 72/91] ipc/sem.c: mundane typo fixes Andrew Morton
2021-05-07  1:05 ` [patch 73/91] mm: fix some typos and code style problems Andrew Morton
2021-05-07  1:05 ` [patch 74/91] drivers/char: remove /dev/kmem for good Andrew Morton
2021-05-07  1:06 ` [patch 75/91] mm: remove xlate_dev_kmem_ptr() Andrew Morton
2021-05-07  1:06 ` Andrew Morton [this message]
2021-05-07  1:06 ` [patch 77/91] arm: print alloc free paths for address in registers Andrew Morton
2021-05-07  1:06 ` [patch 78/91] scripts/spelling.txt: add "overlfow" Andrew Morton
2021-05-07  1:06 ` [patch 79/91] scripts/spelling.txt: add "diabled" typo Andrew Morton
2021-05-07  1:06 ` [patch 80/91] scripts/spelling.txt: add "overflw" Andrew Morton
2021-05-07  1:06 ` [patch 81/91] mm/slab.c: fix spelling mistake "disired" -> "desired" Andrew Morton
2021-05-07  1:06 ` [patch 82/91] include/linux/pgtable.h: few spelling fixes Andrew Morton
2021-05-07  1:06 ` [patch 83/91] kernel/umh.c: fix some spelling mistakes Andrew Morton
2021-05-07  1:06 ` [patch 84/91] kernel/user_namespace.c: fix typos Andrew Morton
2021-05-07  1:06 ` [patch 85/91] kernel/up.c: fix typo Andrew Morton
2021-05-07  1:06 ` [patch 86/91] kernel/sys.c: " Andrew Morton
2021-05-07  1:06 ` [patch 87/91] fs: fat: fix spelling typo of values Andrew Morton
2021-05-07  1:06 ` [patch 88/91] ipc/sem.c: spelling fix Andrew Morton
2021-05-07  1:06 ` [patch 89/91] treewide: remove editor modelines and cruft Andrew Morton
2021-05-07  1:06 ` [patch 90/91] mm: fix typos in comments Andrew Morton
2021-05-07  1:06 ` [patch 91/91] " Andrew Morton
2021-05-07  7:12 ` incoming Linus Torvalds

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