Commit 41badc15 authored by Michel Lespinasse's avatar Michel Lespinasse Committed by Linus Torvalds
Browse files

mm: make do_mmap_pgoff return populate as a size in bytes, not as a bool 



do_mmap_pgoff() rounds up the desired size to the next PAGE_SIZE
multiple, however there was no equivalent code in mm_populate(), which
caused issues.

This could be fixed by introduced the same rounding in mm_populate(),
however I think it's preferable to make do_mmap_pgoff() return populate
as a size rather than as a boolean, so we don't have to duplicate the
size rounding logic in mm_populate().

Signed-off-by: default avatarMichel Lespinasse <walken@google.com>
Acked-by: default avatarRik van Riel <riel@redhat.com>
Tested-by: default avatarAndy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 18693050

fs/aio.c

+2 −3
Original line number Diff line number Diff line
@@ -101,9 +101,8 @@ static int aio_setup_ring(struct kioctx *ctx) 
	struct aio_ring *ring;

	struct aio_ring_info *info = &ctx->ring_info;

	unsigned nr_events = ctx->max_reqs;

	unsigned long size;

	unsigned long size, populate;

	int nr_pages;

	bool populate;



	/* Compensate for the ring buffer's head/tail overlap entry */

	nr_events += 2;	/* 1 is required, 2 for good luck */
@@ -150,7 +149,7 @@ static int aio_setup_ring(struct kioctx *ctx) 
		return -EAGAIN;

	}

	if (populate)

		mm_populate(info->mmap_base, info->mmap_size);

		mm_populate(info->mmap_base, populate);



	ctx->user_id = info->mmap_base;

include/linux/mm.h

+1 −1
Original line number Diff line number Diff line
@@ -1475,7 +1475,7 @@ extern unsigned long mmap_region(struct file *file, unsigned long addr, 
	unsigned long len, vm_flags_t vm_flags, unsigned long pgoff);

extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,

	unsigned long len, unsigned long prot, unsigned long flags,

	unsigned long pgoff, bool *populate);

	unsigned long pgoff, unsigned long *populate);

extern int do_munmap(struct mm_struct *, unsigned long, size_t);



#ifdef CONFIG_MMU

ipc/shm.c

+2 −2
Original line number Diff line number Diff line
@@ -971,7 +971,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr, 
	struct shm_file_data *sfd;

	struct path path;

	fmode_t f_mode;

	bool populate = false;

	unsigned long populate = 0;



	err = -EINVAL;

	if (shmid < 0)
@@ -1078,7 +1078,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr, 
invalid:

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

	if (populate)

		mm_populate(addr, size);

		mm_populate(addr, populate);



out_fput:

	fput(file);

mm/mmap.c

+3 −3
Original line number Diff line number Diff line
@@ -1163,13 +1163,13 @@ static inline unsigned long round_hint_to_min(unsigned long hint) 
unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,

			unsigned long len, unsigned long prot,

			unsigned long flags, unsigned long pgoff,

			bool *populate)

			unsigned long *populate)

{

	struct mm_struct * mm = current->mm;

	struct inode *inode;

	vm_flags_t vm_flags;



	*populate = false;

	*populate = 0;



	/*

	 * Does the application expect PROT_READ to imply PROT_EXEC?
@@ -1307,7 +1307,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, 


	addr = mmap_region(file, addr, len, vm_flags, pgoff);

	if (!IS_ERR_VALUE(addr) && (vm_flags & VM_POPULATE))

		*populate = true;

		*populate = len;

	return addr;

}

mm/nommu.c

+2 −2
Original line number Diff line number Diff line
@@ -1251,7 +1251,7 @@ unsigned long do_mmap_pgoff(struct file *file, 
			    unsigned long prot,

			    unsigned long flags,

			    unsigned long pgoff,

			    bool *populate)

			    unsigned long *populate)

{

	struct vm_area_struct *vma;

	struct vm_region *region;
@@ -1261,7 +1261,7 @@ unsigned long do_mmap_pgoff(struct file *file, 


	kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff);



	*populate = false;

	*populate = 0;



	/* decide whether we should attempt the mapping, and if so what sort of

	 * mapping */

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