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>

2 files changed, 9 insertions, 26 deletions

diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
index 2eb12f13593d..88527492b917 100644
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -50,9 +50,7 @@ static int set_brk(unsigned long start, unsigned long end)
         end = PAGE_ALIGN(end);
         if (end > start) {
                 unsigned long addr;
-                down_write(&current->mm->mmap_sem);
-                addr = do_brk(start, end - start);
-                up_write(&current->mm->mmap_sem);
+                addr = vm_brk(start, end - start);
                 if (BAD_ADDR(addr))
                         return addr;
         }
@@ -280,9 +278,7 @@ static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
                 pos = 32;
                 map_size = ex.a_text+ex.a_data;
 #endif
-                down_write(&current->mm->mmap_sem);
-                error = do_brk(text_addr & PAGE_MASK, map_size);
-                up_write(&current->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 @@ static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 
                 if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
                         loff_t pos = fd_offset;
-                        down_write(&current->mm->mmap_sem);
-                        do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
-                        up_write(&current->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 @@ static int load_aout_library(struct file *file)
                                "N_TXTOFF is not page aligned. Please convert library: %s\n",
                                file->f_path.dentry->d_name.name);
                 }
-                down_write(&current->mm->mmap_sem);
-                do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
-                up_write(&current->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 @@ static int load_aout_library(struct file *file)
         len = PAGE_ALIGN(ex.a_text + ex.a_data);
         bss = ex.a_text + ex.a_data + ex.a_bss;
         if (bss > len) {
-                down_write(&current->mm->mmap_sem);
-                error = do_brk(start_addr + len, bss - len);
-                up_write(&current->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 48ffb3dc610a..0708a0bf0ba9 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -82,9 +82,7 @@ static int set_brk(unsigned long start, unsigned long end)
         end = ELF_PAGEALIGN(end);
         if (end > start) {
                 unsigned long addr;
-                down_write(&current->mm->mmap_sem);
-                addr = do_brk(start, end - start);
-                up_write(&current->mm->mmap_sem);
+                addr = vm_brk(start, end - start);
                 if (BAD_ADDR(addr))
                         return addr;
         }
@@ -514,9 +512,7 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
                 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
 
                 /* Map the last of the bss segment */
-                down_write(&current->mm->mmap_sem);
-                error = do_brk(elf_bss, last_bss - elf_bss);
-                up_write(&current->mm->mmap_sem);
+                error = vm_brk(elf_bss, last_bss - elf_bss);
                 if (BAD_ADDR(error))
                         goto out_close;
         }
@@ -1072,11 +1068,8 @@ static int load_elf_library(struct file *file)
         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(&current->mm->mmap_sem);
-                do_brk(len, bss - len);
-                up_write(&current->mm->mmap_sem);
-        }
+        if (bss > len)
+                vm_brk(len, bss - len);
         error = 0;
 
 out_free_ph: