hugetlbfs: fix mmap failure in unaligned size request

commit af73e4d9506d3b797509f3c030e7dcd554f7d9c4 upstream.

The current kernel returns -EINVAL unless a given mmap length is
"almost" hugepage aligned.  This is because in sys_mmap_pgoff() the
given length is passed to vm_mmap_pgoff() as it is without being aligned
with hugepage boundary.

This is a regression introduced in commit 40716e29243d ("hugetlbfs: fix
alignment of huge page requests"), where alignment code is pushed into
hugetlb_file_setup() and the variable len in caller side is not changed.

To fix this, this patch partially reverts that commit, and adds
alignment code in caller side.  And it also introduces hstate_sizelog()
in order to get proper hstate to specified hugepage size.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=56881

[akpm@linux-foundation.org: fix warning when CONFIG_HUGETLB_PAGE=n]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: <iceman_dvd@yahoo.com>
Cc: Steven Truelove <steven.truelove@utoronto.ca>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 001ef01d2fe2705a6767075032ea9f9f9ed0ec04..36ad5b4aae623e675197936c996848c476bcc648 100644 (file)
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -927,9 +927,13 @@ static int can_do_hugetlb_shm(void)
        return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group);
 }
 
-struct file *hugetlb_file_setup(const char *name, unsigned long addr,
-                               size_t size, vm_flags_t acctflag,
-                               struct user_struct **user, int creat_flags)
+/*
+ * Note that size should be aligned to proper hugepage size in caller side,
+ * otherwise hugetlb_reserve_pages reserves one less hugepages than intended.
+ */
+struct file *hugetlb_file_setup(const char *name, size_t size,
+                               vm_flags_t acctflag, struct user_struct **user,
+                               int creat_flags)
 {
        int error = -ENOMEM;
        struct file *file;
@@ -937,8 +941,6 @@ struct file *hugetlb_file_setup(const char *name, unsigned long addr,
        struct path path;
        struct dentry *root;
        struct qstr quick_string;
-       struct hstate *hstate;
-       unsigned long num_pages;
 
        *user = NULL;
        if (!hugetlbfs_vfsmount)
@@ -972,12 +974,10 @@ struct file *hugetlb_file_setup(const char *name, unsigned long addr,
        if (!inode)
                goto out_dentry;
 
-       hstate = hstate_inode(inode);
-       size += addr & ~huge_page_mask(hstate);
-       num_pages = ALIGN(size, huge_page_size(hstate)) >>
-                       huge_page_shift(hstate);
        error = -ENOMEM;
-       if (hugetlb_reserve_pages(inode, 0, num_pages, NULL, acctflag))
+       if (hugetlb_reserve_pages(inode, 0,
+                       size >> huge_page_shift(hstate_inode(inode)), NULL,
+                       acctflag))
                goto out_inode;
 
        d_instantiate(path.dentry, inode);

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 000837e126e64b3b0e64d67aff67a3c9626e4c5e..2c36a713a326750363d45d52a63a551742613a35 100644 (file)
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -152,8 +152,7 @@ static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb)
 
 extern const struct file_operations hugetlbfs_file_operations;
 extern const struct vm_operations_struct hugetlb_vm_ops;
-struct file *hugetlb_file_setup(const char *name, unsigned long addr,
-                               size_t size, vm_flags_t acct,
+struct file *hugetlb_file_setup(const char *name, size_t size, vm_flags_t acct,
                                struct user_struct **user, int creat_flags);
 
 static inline int is_file_hugepages(struct file *file)
@@ -170,8 +169,8 @@ static inline int is_file_hugepages(struct file *file)
 
 #define is_file_hugepages(file)                        0
 static inline struct file *
-hugetlb_file_setup(const char *name, unsigned long addr, size_t size,
-               vm_flags_t acctflag, struct user_struct **user, int creat_flags)
+hugetlb_file_setup(const char *name, size_t size, vm_flags_t acctflag,
+               struct user_struct **user, int creat_flags)
 {
        return ERR_PTR(-ENOSYS);
 }
@@ -294,7 +293,7 @@ static inline unsigned hstate_index_to_shift(unsigned index)
        return hstates[index].order + PAGE_SHIFT;
 }
 
-#else
+#else  /* CONFIG_HUGETLB_PAGE */
 struct hstate {};
 #define alloc_huge_page_node(h, nid) NULL
 #define alloc_bootmem_huge_page(h) NULL

diff --git a/ipc/shm.c b/ipc/shm.c
index 85d81b454e8f6542848beca4d0668cd6796874f3..a02ef5781ce97baeb79929474847213150dfa42d 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -479,10 +479,12 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
 
        sprintf (name, "SYSV%08x", key);
        if (shmflg & SHM_HUGETLB) {
+               size_t hugesize = ALIGN(size, huge_page_size(&default_hstate));
+
                /* hugetlb_file_setup applies strict accounting */
                if (shmflg & SHM_NORESERVE)
                        acctflag = VM_NORESERVE;
-               file = hugetlb_file_setup(name, 0, size, acctflag,
+               file = hugetlb_file_setup(name, hugesize, acctflag,
                                        &shp->mlock_user, HUGETLB_SHMFS_INODE);
        } else {
                /*

diff --git a/mm/mmap.c b/mm/mmap.c
index 3635d47894861b297c76e65cc176623e31a2ca8b..ed884dd9674b270d301e2e36ce79661df6e78e95 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1130,15 +1130,19 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
                file = fget(fd);
                if (!file)
                        goto out;
+               if (is_file_hugepages(file))
+                       len = ALIGN(len, huge_page_size(hstate_file(file)));
        } else if (flags & MAP_HUGETLB) {
                struct user_struct *user = NULL;
+
+               len = ALIGN(len, huge_page_size(&default_hstate));
                /*
                 * VM_NORESERVE is used because the reservations will be
                 * taken when vm_ops->mmap() is called
                 * A dummy user value is used because we are not locking
                 * memory so no accounting is necessary
                 */
-               file = hugetlb_file_setup(HUGETLB_ANON_FILE, addr, len,
+               file = hugetlb_file_setup(HUGETLB_ANON_FILE, len,
                                                VM_NORESERVE, &user,
                                                HUGETLB_ANONHUGE_INODE);
                if (IS_ERR(file))