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>
diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
index d511d95..b6817ee 100644
--- a/arch/x86/ia32/ia32_aout.c
+++ b/arch/x86/ia32/ia32_aout.c
@@ -119,9 +119,7 @@
end = PAGE_ALIGN(end);
if (end <= start)
return;
- down_write(¤t->mm->mmap_sem);
- do_brk(start, end - start);
- up_write(¤t->mm->mmap_sem);
+ vm_brk(start, end - start);
}
#ifdef CORE_DUMP
@@ -332,9 +330,7 @@
pos = 32;
map_size = ex.a_text+ex.a_data;
- down_write(¤t->mm->mmap_sem);
- error = do_brk(text_addr & PAGE_MASK, map_size);
- up_write(¤t->mm->mmap_sem);
+ error = vm_brk(text_addr & PAGE_MASK, map_size);
if (error != (text_addr & PAGE_MASK)) {
send_sig(SIGKILL, current, 0);
@@ -373,9 +369,7 @@
if (!bprm->file->f_op->mmap || (fd_offset & ~PAGE_MASK) != 0) {
loff_t pos = fd_offset;
- down_write(¤t->mm->mmap_sem);
- do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
- up_write(¤t->mm->mmap_sem);
+ vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
bprm->file->f_op->read(bprm->file,
(char __user *)N_TXTADDR(ex),
ex.a_text+ex.a_data, &pos);
@@ -476,9 +470,7 @@
error_time = jiffies;
}
#endif
- down_write(¤t->mm->mmap_sem);
- do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
- up_write(¤t->mm->mmap_sem);
+ vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
file->f_op->read(file, (char __user *)start_addr,
ex.a_text + ex.a_data, &pos);
@@ -503,9 +495,7 @@
len = PAGE_ALIGN(ex.a_text + ex.a_data);
bss = ex.a_text + ex.a_data + ex.a_bss;
if (bss > len) {
- down_write(¤t->mm->mmap_sem);
- error = do_brk(start_addr + len, bss - len);
- up_write(¤t->mm->mmap_sem);
+ error = vm_brk(start_addr + len, bss - len);
retval = error;
if (error != start_addr + len)
goto out;
diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
index 2eb12f1..8852749 100644
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -50,9 +50,7 @@
end = PAGE_ALIGN(end);
if (end > start) {
unsigned long addr;
- down_write(¤t->mm->mmap_sem);
- addr = do_brk(start, end - start);
- up_write(¤t->mm->mmap_sem);
+ addr = vm_brk(start, end - start);
if (BAD_ADDR(addr))
return addr;
}
@@ -280,9 +278,7 @@
pos = 32;
map_size = ex.a_text+ex.a_data;
#endif
- down_write(¤t->mm->mmap_sem);
- error = do_brk(text_addr & PAGE_MASK, map_size);
- up_write(¤t->mm->mmap_sem);
+ error = vm_brk(text_addr & PAGE_MASK, map_size);
if (error != (text_addr & PAGE_MASK)) {
send_sig(SIGKILL, current, 0);
return error;
@@ -313,9 +309,7 @@
if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
loff_t pos = fd_offset;
- down_write(¤t->mm->mmap_sem);
- do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
- up_write(¤t->mm->mmap_sem);
+ vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
bprm->file->f_op->read(bprm->file,
(char __user *)N_TXTADDR(ex),
ex.a_text+ex.a_data, &pos);
@@ -412,9 +406,7 @@
"N_TXTOFF is not page aligned. Please convert library: %s\n",
file->f_path.dentry->d_name.name);
}
- down_write(¤t->mm->mmap_sem);
- do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
- up_write(¤t->mm->mmap_sem);
+ vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
file->f_op->read(file, (char __user *)start_addr,
ex.a_text + ex.a_data, &pos);
@@ -438,9 +430,7 @@
len = PAGE_ALIGN(ex.a_text + ex.a_data);
bss = ex.a_text + ex.a_data + ex.a_bss;
if (bss > len) {
- down_write(¤t->mm->mmap_sem);
- error = do_brk(start_addr + len, bss - len);
- up_write(¤t->mm->mmap_sem);
+ error = vm_brk(start_addr + len, bss - len);
retval = error;
if (error != start_addr + len)
goto out;
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 48ffb3d..0708a0b 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -82,9 +82,7 @@
end = ELF_PAGEALIGN(end);
if (end > start) {
unsigned long addr;
- down_write(¤t->mm->mmap_sem);
- addr = do_brk(start, end - start);
- up_write(¤t->mm->mmap_sem);
+ addr = vm_brk(start, end - start);
if (BAD_ADDR(addr))
return addr;
}
@@ -514,9 +512,7 @@
elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
/* Map the last of the bss segment */
- down_write(¤t->mm->mmap_sem);
- error = do_brk(elf_bss, last_bss - elf_bss);
- up_write(¤t->mm->mmap_sem);
+ error = vm_brk(elf_bss, last_bss - elf_bss);
if (BAD_ADDR(error))
goto out_close;
}
@@ -1072,11 +1068,8 @@
len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
ELF_MIN_ALIGN - 1);
bss = eppnt->p_memsz + eppnt->p_vaddr;
- if (bss > len) {
- down_write(¤t->mm->mmap_sem);
- do_brk(len, bss - len);
- up_write(¤t->mm->mmap_sem);
- }
+ if (bss > len)
+ vm_brk(len, bss - len);
error = 0;
out_free_ph:
diff --git a/include/linux/mm.h b/include/linux/mm.h
index d8738a4..bfee4ad 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1415,7 +1415,8 @@
extern int do_munmap(struct mm_struct *, unsigned long, size_t);
-extern unsigned long do_brk(unsigned long, unsigned long);
+/* These take the mm semaphore themselves */
+extern unsigned long vm_brk(unsigned long, unsigned long);
/* truncate.c */
extern void truncate_inode_pages(struct address_space *, loff_t);
diff --git a/mm/mmap.c b/mm/mmap.c
index a7bf6a3..df51891 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -240,6 +240,8 @@
return next;
}
+static unsigned long do_brk(unsigned long addr, unsigned long len);
+
SYSCALL_DEFINE1(brk, unsigned long, brk)
{
unsigned long rlim, retval;
@@ -2136,7 +2138,7 @@
* anonymous maps. eventually we may be able to do some
* brk-specific accounting here.
*/
-unsigned long do_brk(unsigned long addr, unsigned long len)
+static unsigned long do_brk(unsigned long addr, unsigned long len)
{
struct mm_struct * mm = current->mm;
struct vm_area_struct * vma, * prev;
@@ -2232,7 +2234,17 @@
return addr;
}
-EXPORT_SYMBOL(do_brk);
+unsigned long vm_brk(unsigned long addr, unsigned long len)
+{
+ struct mm_struct *mm = current->mm;
+ unsigned long ret;
+
+ down_write(&mm->mmap_sem);
+ ret = do_brk(addr, len);
+ up_write(&mm->mmap_sem);
+ return ret;
+}
+EXPORT_SYMBOL(vm_brk);
/* Release all mmaps. */
void exit_mmap(struct mm_struct *mm)
diff --git a/mm/nommu.c b/mm/nommu.c
index f59e170..6341933 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1744,7 +1744,7 @@
kleave("");
}
-unsigned long do_brk(unsigned long addr, unsigned long len)
+unsigned long vm_brk(unsigned long addr, unsigned long len)
{
return -ENOMEM;
}