Commit e4eb1ff6 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3b422e9c

arch/x86/ia32/ia32_aout.c

+5 −15
Original line number Diff line number Diff line
@@ -119,9 +119,7 @@ static void set_brk(unsigned long start, unsigned long end) 
	end = PAGE_ALIGN(end);

	if (end <= start)

		return;

	down_write(&current->mm->mmap_sem);

	do_brk(start, end - start);

	up_write(&current->mm->mmap_sem);

	vm_brk(start, end - start);

}



#ifdef CORE_DUMP
@@ -332,9 +330,7 @@ static int load_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs) 
		pos = 32;

		map_size = ex.a_text+ex.a_data;



		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);
@@ -373,9 +369,7 @@ 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);
@@ -476,9 +470,7 @@ static int load_aout_library(struct file *file) 
			error_time = jiffies;

		}

#endif

		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);
@@ -503,9 +495,7 @@ 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;

fs/binfmt_aout.c

+5 −15
Original line number Diff line number Diff line
@@ -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;

fs/binfmt_elf.c

+4 −11
Original line number Diff line number Diff line
@@ -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:

include/linux/mm.h

+2 −1
Original line number Diff line number Diff line
@@ -1415,7 +1415,8 @@ out: 


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);

mm/mmap.c

+14 −2
Original line number Diff line number Diff line
@@ -240,6 +240,8 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma) 
	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 @@ static inline void verify_mm_writelocked(struct mm_struct *mm) 
 *  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 @@ out: 
	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)

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