Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
VM: add "vm_brk()" helper function
It does the same thing as "do_brk()", except it handles the VM locking
too.
It turns out that all external callers want that anyway, so we can make
do_brk() static to just mm/mmap.c while at it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+31
-45
+5
-15
arch/x86/ia32/ia32_aout.c
+5
-15
arch/x86/ia32/ia32_aout.c
···
119
119
end = PAGE_ALIGN(end);
120
120
if (end <= start)
121
121
return;
122
-
down_write(¤t->mm->mmap_sem);
123
-
do_brk(start, end - start);
124
-
up_write(¤t->mm->mmap_sem);
122
+
vm_brk(start, end - start);
125
123
}
126
124
127
125
#ifdef CORE_DUMP
···
330
332
pos = 32;
331
333
map_size = ex.a_text+ex.a_data;
332
334
333
-
down_write(¤t->mm->mmap_sem);
334
-
error = do_brk(text_addr & PAGE_MASK, map_size);
335
-
up_write(¤t->mm->mmap_sem);
335
+
error = vm_brk(text_addr & PAGE_MASK, map_size);
336
336
337
337
if (error != (text_addr & PAGE_MASK)) {
338
338
send_sig(SIGKILL, current, 0);
···
369
373
if (!bprm->file->f_op->mmap || (fd_offset & ~PAGE_MASK) != 0) {
370
374
loff_t pos = fd_offset;
371
375
372
-
down_write(¤t->mm->mmap_sem);
373
-
do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
374
-
up_write(¤t->mm->mmap_sem);
376
+
vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
375
377
bprm->file->f_op->read(bprm->file,
376
378
(char __user *)N_TXTADDR(ex),
377
379
ex.a_text+ex.a_data, &pos);
···
470
476
error_time = jiffies;
471
477
}
472
478
#endif
473
-
down_write(¤t->mm->mmap_sem);
474
-
do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
475
-
up_write(¤t->mm->mmap_sem);
479
+
vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
476
480
477
481
file->f_op->read(file, (char __user *)start_addr,
478
482
ex.a_text + ex.a_data, &pos);
···
495
503
len = PAGE_ALIGN(ex.a_text + ex.a_data);
496
504
bss = ex.a_text + ex.a_data + ex.a_bss;
497
505
if (bss > len) {
498
-
down_write(¤t->mm->mmap_sem);
499
-
error = do_brk(start_addr + len, bss - len);
500
-
up_write(¤t->mm->mmap_sem);
506
+
error = vm_brk(start_addr + len, bss - len);
501
507
retval = error;
502
508
if (error != start_addr + len)
503
509
goto out;
+5
-15
fs/binfmt_aout.c
+5
-15
fs/binfmt_aout.c
···
50
50
end = PAGE_ALIGN(end);
51
51
if (end > start) {
52
52
unsigned long addr;
53
-
down_write(¤t->mm->mmap_sem);
54
-
addr = do_brk(start, end - start);
55
-
up_write(¤t->mm->mmap_sem);
53
+
addr = vm_brk(start, end - start);
56
54
if (BAD_ADDR(addr))
57
55
return addr;
58
56
}
···
278
280
pos = 32;
279
281
map_size = ex.a_text+ex.a_data;
280
282
#endif
281
-
down_write(¤t->mm->mmap_sem);
282
-
error = do_brk(text_addr & PAGE_MASK, map_size);
283
-
up_write(¤t->mm->mmap_sem);
283
+
error = vm_brk(text_addr & PAGE_MASK, map_size);
284
284
if (error != (text_addr & PAGE_MASK)) {
285
285
send_sig(SIGKILL, current, 0);
286
286
return error;
···
309
313
310
314
if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
311
315
loff_t pos = fd_offset;
312
-
down_write(¤t->mm->mmap_sem);
313
-
do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
314
-
up_write(¤t->mm->mmap_sem);
316
+
vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
315
317
bprm->file->f_op->read(bprm->file,
316
318
(char __user *)N_TXTADDR(ex),
317
319
ex.a_text+ex.a_data, &pos);
···
406
412
"N_TXTOFF is not page aligned. Please convert library: %s\n",
407
413
file->f_path.dentry->d_name.name);
408
414
}
409
-
down_write(¤t->mm->mmap_sem);
410
-
do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
411
-
up_write(¤t->mm->mmap_sem);
415
+
vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
412
416
413
417
file->f_op->read(file, (char __user *)start_addr,
414
418
ex.a_text + ex.a_data, &pos);
···
430
438
len = PAGE_ALIGN(ex.a_text + ex.a_data);
431
439
bss = ex.a_text + ex.a_data + ex.a_bss;
432
440
if (bss > len) {
433
-
down_write(¤t->mm->mmap_sem);
434
-
error = do_brk(start_addr + len, bss - len);
435
-
up_write(¤t->mm->mmap_sem);
441
+
error = vm_brk(start_addr + len, bss - len);
436
442
retval = error;
437
443
if (error != start_addr + len)
438
444
goto out;
+4
-11
fs/binfmt_elf.c
+4
-11
fs/binfmt_elf.c
···
82
82
end = ELF_PAGEALIGN(end);
83
83
if (end > start) {
84
84
unsigned long addr;
85
-
down_write(¤t->mm->mmap_sem);
86
-
addr = do_brk(start, end - start);
87
-
up_write(¤t->mm->mmap_sem);
85
+
addr = vm_brk(start, end - start);
88
86
if (BAD_ADDR(addr))
89
87
return addr;
90
88
}
···
512
514
elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
513
515
514
516
/* Map the last of the bss segment */
515
-
down_write(¤t->mm->mmap_sem);
516
-
error = do_brk(elf_bss, last_bss - elf_bss);
517
-
up_write(¤t->mm->mmap_sem);
517
+
error = vm_brk(elf_bss, last_bss - elf_bss);
518
518
if (BAD_ADDR(error))
519
519
goto out_close;
520
520
}
···
1068
1072
len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1069
1073
ELF_MIN_ALIGN - 1);
1070
1074
bss = eppnt->p_memsz + eppnt->p_vaddr;
1071
-
if (bss > len) {
1072
-
down_write(¤t->mm->mmap_sem);
1073
-
do_brk(len, bss - len);
1074
-
up_write(¤t->mm->mmap_sem);
1075
-
}
1075
+
if (bss > len)
1076
+
vm_brk(len, bss - len);
1076
1077
error = 0;
1077
1078
1078
1079
out_free_ph:
+2
-1
include/linux/mm.h
+2
-1
include/linux/mm.h
···
1415
1415
1416
1416
extern int do_munmap(struct mm_struct *, unsigned long, size_t);
1417
1417
1418
-
extern unsigned long do_brk(unsigned long, unsigned long);
1418
+
/* These take the mm semaphore themselves */
1419
+
extern unsigned long vm_brk(unsigned long, unsigned long);
1419
1420
1420
1421
/* truncate.c */
1421
1422
extern void truncate_inode_pages(struct address_space *, loff_t);
+14
-2
mm/mmap.c
+14
-2
mm/mmap.c
···
240
240
return next;
241
241
}
242
242
243
+
static unsigned long do_brk(unsigned long addr, unsigned long len);
244
+
243
245
SYSCALL_DEFINE1(brk, unsigned long, brk)
244
246
{
245
247
unsigned long rlim, retval;
···
2138
2136
* anonymous maps. eventually we may be able to do some
2139
2137
* brk-specific accounting here.
2140
2138
*/
2141
-
unsigned long do_brk(unsigned long addr, unsigned long len)
2139
+
static unsigned long do_brk(unsigned long addr, unsigned long len)
2142
2140
{
2143
2141
struct mm_struct * mm = current->mm;
2144
2142
struct vm_area_struct * vma, * prev;
···
2234
2232
return addr;
2235
2233
}
2236
2234
2237
-
EXPORT_SYMBOL(do_brk);
2235
+
unsigned long vm_brk(unsigned long addr, unsigned long len)
2236
+
{
2237
+
struct mm_struct *mm = current->mm;
2238
+
unsigned long ret;
2239
+
2240
+
down_write(&mm->mmap_sem);
2241
+
ret = do_brk(addr, len);
2242
+
up_write(&mm->mmap_sem);
2243
+
return ret;
2244
+
}
2245
+
EXPORT_SYMBOL(vm_brk);
2238
2246
2239
2247
/* Release all mmaps. */
2240
2248
void exit_mmap(struct mm_struct *mm)