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: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/aio.c b/fs/aio.c
index 82eec7c7b4bb25ff55230f1392fdb4467ff27d90..064bfbe37566adc715832ebb968b588b9f2d1905 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -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;
 

diff --git a/include/linux/mm.h b/include/linux/mm.h
index e7fedf5b8c03d5f4a9168bbd09f6117aed713536..0fb35f7d277b6b6de477009fcd21bf9e114c5192 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1477,7 +1477,7 @@ 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

diff --git a/ipc/shm.c b/ipc/shm.c
index 9f047ba69e624db699f7c3bf6a090dd335f4e7ec..be3ec9ae454e5b9bf5fa0d84bacd6337d57daeaa 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -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);

diff --git a/mm/mmap.c b/mm/mmap.c
index 39a3944e1658ad99519631833d1029c3b8e2247c..44bb4d86988456d0fb806a62445a798a7f307400 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -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;
 }
 

diff --git a/mm/nommu.c b/mm/nommu.c
index 7296a5a280e7d798b10718bf1cd9998fa0f640a3..18c1b932e2c4450de1aa28d8e250420ced267b47 100644 (file)
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -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 */

diff --git a/mm/util.c b/mm/util.c
index 13467e043e9e24b1d0c6f92560b33f8861f58eca..3704bf1bef9409ee1b48c8ae8867b1383b6a41f2 100644 (file)
--- a/mm/util.c
+++ b/mm/util.c
@@ -355,7 +355,7 @@ unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr,
 {
        unsigned long ret;
        struct mm_struct *mm = current->mm;
-       bool populate;
+       unsigned long populate;
 
        ret = security_mmap_file(file, prot, flag);
        if (!ret) {
@@ -363,8 +363,8 @@ unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr,
                ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff,
                                    &populate);
                up_write(&mm->mmap_sem);
-               if (!IS_ERR_VALUE(ret) && populate)
-                       mm_populate(ret, len);
+               if (populate)
+                       mm_populate(ret, populate);
        }
        return ret;
 }