Commit 40716e29 authored by Steven Truelove's avatar Steven Truelove Committed by Linus Torvalds
Browse files

hugetlbfs: fix alignment of huge page requests 



When calling shmget() with SHM_HUGETLB, shmget aligns the request size to
PAGE_SIZE, but this is not sufficient.

Modify hugetlb_file_setup() to align requests to the huge page size, and
to accept an address argument so that all alignment checks can be
performed in hugetlb_file_setup(), rather than in its callers.  Change
newseg() and mmap_pgoff() to match the new prototype and eliminate a now
redundant alignment check.

[akpm@linux-foundation.org: fix build]
Signed-off-by: default avatarSteven Truelove <steven.truelove@utoronto.ca>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 21a3c273

fs/hugetlbfs/inode.c

+9 −5
Original line number Diff line number Diff line
@@ -935,8 +935,8 @@ 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, size_t size,

				vm_flags_t acctflag,

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)

{

	int error = -ENOMEM;
@@ -945,6 +945,8 @@ struct file *hugetlb_file_setup(const char *name, size_t size, 
	struct path path;

	struct dentry *root;

	struct qstr quick_string;

	struct hstate *hstate;

	unsigned long num_pages;



	*user = NULL;

	if (!hugetlbfs_vfsmount)
@@ -978,10 +980,12 @@ struct file *hugetlb_file_setup(const char *name, size_t size, 
	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,

			size >> huge_page_shift(hstate_inode(inode)), NULL,

			acctflag))

	if (hugetlb_reserve_pages(inode, 0, num_pages, NULL, acctflag))

		goto out_inode;



	d_instantiate(path.dentry, inode);

include/linux/hugetlb.h

+4 −2
Original line number Diff line number Diff line
@@ -152,7 +152,8 @@ 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, size_t size, vm_flags_t acct,

struct file *hugetlb_file_setup(const char *name, unsigned long addr,

				size_t size, vm_flags_t acct,

				struct user_struct **user, int creat_flags);



static inline int is_file_hugepages(struct file *file)
@@ -168,7 +169,8 @@ static inline int is_file_hugepages(struct file *file) 
#else /* !CONFIG_HUGETLBFS */



#define is_file_hugepages(file)			0

static inline struct file *hugetlb_file_setup(const char *name, size_t size,

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)

{

	return ERR_PTR(-ENOSYS);

ipc/shm.c

+1 −1
Original line number Diff line number Diff line
@@ -482,7 +482,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) 
		/* hugetlb_file_setup applies strict accounting */

		if (shmflg & SHM_NORESERVE)

			acctflag = VM_NORESERVE;

		file = hugetlb_file_setup(name, size, acctflag,

		file = hugetlb_file_setup(name, 0, size, acctflag,

					&shp->mlock_user, HUGETLB_SHMFS_INODE);

	} else {

		/*

mm/mmap.c

+3 −3
Original line number Diff line number Diff line
@@ -1099,9 +1099,9 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, 
		 * A dummy user value is used because we are not locking

		 * memory so no accounting is necessary

		 */

		len = ALIGN(len, huge_page_size(&default_hstate));

		file = hugetlb_file_setup(HUGETLB_ANON_FILE, len, VM_NORESERVE,

						&user, HUGETLB_ANONHUGE_INODE);

		file = hugetlb_file_setup(HUGETLB_ANON_FILE, addr, len,

						VM_NORESERVE, &user,

						HUGETLB_ANONHUGE_INODE);

		if (IS_ERR(file))

			return PTR_ERR(file);

	}

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