Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
authored by
David Hildenbrand
and committed by
Linus Torvalds
f7c8ce44
f2e762ba
+1
-126
-1
include/linux/vmalloc.h
-1
include/linux/vmalloc.h
-10
mm/nommu.c
-10
mm/nommu.c
···
210
210
return count;
211
211
}
212
212
213
-
long vwrite(char *buf, char *addr, unsigned long count)
214
-
{
215
-
/* Don't allow overflow */
216
-
if ((unsigned long) addr + count < count)
217
-
count = -(unsigned long) addr;
218
-
219
-
memcpy(addr, buf, count);
220
-
return count;
221
-
}
222
-
223
213
/*
224
214
* vmalloc - allocate virtually contiguous memory
225
215
*
+1
-115
mm/vmalloc.c
+1
-115
mm/vmalloc.c
···
3146
3146
* kmap() and get small overhead in this access function.
3147
3147
*/
3148
3148
if (p) {
3149
-
/*
3150
-
* we can expect USER0 is not used (see vread/vwrite's
3151
-
* function description)
3152
-
*/
3149
+
/* We can expect USER0 is not used -- see vread() */
3153
3150
void *map = kmap_atomic(p);
3154
3151
memcpy(buf, map + offset, length);
3155
3152
kunmap_atomic(map);
3156
3153
} else
3157
3154
memset(buf, 0, length);
3158
3155
3159
-
addr += length;
3160
-
buf += length;
3161
-
copied += length;
3162
-
count -= length;
3163
-
}
3164
-
return copied;
3165
-
}
3166
-
3167
-
static int aligned_vwrite(char *buf, char *addr, unsigned long count)
3168
-
{
3169
-
struct page *p;
3170
-
int copied = 0;
3171
-
3172
-
while (count) {
3173
-
unsigned long offset, length;
3174
-
3175
-
offset = offset_in_page(addr);
3176
-
length = PAGE_SIZE - offset;
3177
-
if (length > count)
3178
-
length = count;
3179
-
p = vmalloc_to_page(addr);
3180
-
/*
3181
-
* To do safe access to this _mapped_ area, we need
3182
-
* lock. But adding lock here means that we need to add
3183
-
* overhead of vmalloc()/vfree() calles for this _debug_
3184
-
* interface, rarely used. Instead of that, we'll use
3185
-
* kmap() and get small overhead in this access function.
3186
-
*/
3187
-
if (p) {
3188
-
/*
3189
-
* we can expect USER0 is not used (see vread/vwrite's
3190
-
* function description)
3191
-
*/
3192
-
void *map = kmap_atomic(p);
3193
-
memcpy(map + offset, buf, length);
3194
-
kunmap_atomic(map);
3195
-
}
3196
3156
addr += length;
3197
3157
buf += length;
3198
3158
copied += length;
···
3240
3280
if (buf != buf_start + buflen)
3241
3281
memset(buf, 0, buflen - (buf - buf_start));
3242
3282
3243
-
return buflen;
3244
-
}
3245
-
3246
-
/**
3247
-
* vwrite() - write vmalloc area in a safe way.
3248
-
* @buf: buffer for source data
3249
-
* @addr: vm address.
3250
-
* @count: number of bytes to be read.
3251
-
*
3252
-
* This function checks that addr is a valid vmalloc'ed area, and
3253
-
* copy data from a buffer to the given addr. If specified range of
3254
-
* [addr...addr+count) includes some valid address, data is copied from
3255
-
* proper area of @buf. If there are memory holes, no copy to hole.
3256
-
* IOREMAP area is treated as memory hole and no copy is done.
3257
-
*
3258
-
* If [addr...addr+count) doesn't includes any intersects with alive
3259
-
* vm_struct area, returns 0. @buf should be kernel's buffer.
3260
-
*
3261
-
* Note: In usual ops, vwrite() is never necessary because the caller
3262
-
* should know vmalloc() area is valid and can use memcpy().
3263
-
* This is for routines which have to access vmalloc area without
3264
-
* any information, as /dev/kmem.
3265
-
*
3266
-
* Return: number of bytes for which addr and buf should be
3267
-
* increased (same number as @count) or %0 if [addr...addr+count)
3268
-
* doesn't include any intersection with valid vmalloc area
3269
-
*/
3270
-
long vwrite(char *buf, char *addr, unsigned long count)
3271
-
{
3272
-
struct vmap_area *va;
3273
-
struct vm_struct *vm;
3274
-
char *vaddr;
3275
-
unsigned long n, buflen;
3276
-
int copied = 0;
3277
-
3278
-
/* Don't allow overflow */
3279
-
if ((unsigned long) addr + count < count)
3280
-
count = -(unsigned long) addr;
3281
-
buflen = count;
3282
-
3283
-
spin_lock(&vmap_area_lock);
3284
-
list_for_each_entry(va, &vmap_area_list, list) {
3285
-
if (!count)
3286
-
break;
3287
-
3288
-
if (!va->vm)
3289
-
continue;
3290
-
3291
-
vm = va->vm;
3292
-
vaddr = (char *) vm->addr;
3293
-
if (addr >= vaddr + get_vm_area_size(vm))
3294
-
continue;
3295
-
while (addr < vaddr) {
3296
-
if (count == 0)
3297
-
goto finished;
3298
-
buf++;
3299
-
addr++;
3300
-
count--;
3301
-
}
3302
-
n = vaddr + get_vm_area_size(vm) - addr;
3303
-
if (n > count)
3304
-
n = count;
3305
-
if (!(vm->flags & VM_IOREMAP)) {
3306
-
aligned_vwrite(buf, addr, n);
3307
-
copied++;
3308
-
}
3309
-
buf += n;
3310
-
addr += n;
3311
-
count -= n;
3312
-
}
3313
-
finished:
3314
-
spin_unlock(&vmap_area_lock);
3315
-
if (!copied)
3316
-
return 0;
3317
3283
return buflen;
3318
3284
}
3319
3285