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Subject[PATCH] mlock-as-user for 2.6.8-rc2-mm2
Hi Andrew,

here is the last agreed-on patch that lets normal users mlock
pages up to their rlimit. This patch addresses all the issues
brought up by Chris and Andrea.

Please apply this patch for your next release.

thanks,

Rik

Signed-off-by: Rik van Riel <riel@redhat.com>


--- linux-2.6.8-rc2/include/asm-ppc64/resource.h.mlock 2004-07-18 00:58:57.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-ppc64/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -45,7 +45,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING }, \
--- linux-2.6.8-rc2/include/asm-m68k/resource.h.mlock 2004-07-18 00:57:38.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-m68k/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -39,7 +39,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING }, \
--- linux-2.6.8-rc2/include/asm-parisc/resource.h.mlock 2004-07-18 00:58:57.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-parisc/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -39,7 +39,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING }, \
--- linux-2.6.8-rc2/include/asm-ppc/resource.h.mlock 2004-07-18 00:58:21.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-ppc/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -36,7 +36,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING }, \
--- linux-2.6.8-rc2/include/asm-x86_64/resource.h.mlock 2004-07-18 00:58:57.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-x86_64/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -39,7 +39,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE , PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING }, \
--- linux-2.6.8-rc2/include/asm-ia64/resource.h.mlock 2004-07-18 00:59:03.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-ia64/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -46,7 +46,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING }, \
--- linux-2.6.8-rc2/include/linux/mm.h.mlock 2004-08-04 13:23:15.000000000 -0400
+++ linux-2.6.8-rc2/include/linux/mm.h 2004-08-04 13:25:33.000000000 -0400
@@ -498,9 +498,20 @@ int shmem_set_policy(struct vm_area_stru
struct mempolicy *shmem_get_policy(struct vm_area_struct *vma,
unsigned long addr);
struct file *shmem_file_setup(char * name, loff_t size, unsigned long flags);
-void shmem_lock(struct file * file, int lock);
+int shmem_lock(struct file * file, int lock, struct user_struct *);
int shmem_zero_setup(struct vm_area_struct *);

+static inline int can_do_mlock(void)
+{
+ if (capable(CAP_IPC_LOCK))
+ return 1;
+ if (current->rlim[RLIMIT_MEMLOCK].rlim_cur != 0)
+ return 1;
+ return 0;
+}
+extern int user_can_mlock(size_t, struct user_struct *);
+extern void user_subtract_mlock(size_t, struct user_struct *);
+
/*
* Parameter block passed down to zap_pte_range in exceptional cases.
*/
--- linux-2.6.8-rc2/include/linux/shm.h.mlock 2004-07-18 00:59:02.000000000 -0400
+++ linux-2.6.8-rc2/include/linux/shm.h 2004-08-04 13:25:33.000000000 -0400
@@ -84,6 +84,7 @@ struct shmid_kernel /* private to the ke
time_t shm_ctim;
pid_t shm_cprid;
pid_t shm_lprid;
+ struct user_struct * mlock_user;
};

/* shm_mode upper byte flags */
--- linux-2.6.8-rc2/include/linux/sched.h.mlock 2004-08-04 13:23:17.000000000 -0400
+++ linux-2.6.8-rc2/include/linux/sched.h 2004-08-04 13:25:33.000000000 -0400
@@ -333,6 +333,7 @@ struct user_struct {
atomic_t sigpending; /* How many pending signals does this user have? */
/* protected by mq_lock */
unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
+ unsigned long locked_shm; /* How many pages of mlocked shm ? */

/* Hash table maintenance information */
struct list_head uidhash_list;
--- linux-2.6.8-rc2/include/asm-arm/resource.h.mlock 2004-07-18 00:59:06.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-arm/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -39,7 +39,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING}, \
--- linux-2.6.8-rc2/include/asm-v850/resource.h.mlock 2004-07-18 00:57:40.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-v850/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -39,7 +39,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING }, \
--- linux-2.6.8-rc2/include/asm-sparc/resource.h.mlock 2004-07-18 00:57:42.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-sparc/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -44,7 +44,7 @@
{ 0, RLIM_INFINITY}, \
{RLIM_INFINITY, RLIM_INFINITY}, \
{INR_OPEN, INR_OPEN}, {0, 0}, \
- {RLIM_INFINITY, RLIM_INFINITY}, \
+ {PAGE_SIZE, PAGE_SIZE}, \
{RLIM_INFINITY, RLIM_INFINITY}, \
{RLIM_INFINITY, RLIM_INFINITY}, \
{MAX_SIGPENDING, MAX_SIGPENDING}, \
--- linux-2.6.8-rc2/include/asm-alpha/resource.h.mlock 2004-07-18 00:57:41.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-alpha/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -41,7 +41,7 @@
{INR_OPEN, INR_OPEN}, /* RLIMIT_NOFILE */ \
{LONG_MAX, LONG_MAX}, /* RLIMIT_AS */ \
{LONG_MAX, LONG_MAX}, /* RLIMIT_NPROC */ \
- {LONG_MAX, LONG_MAX}, /* RLIMIT_MEMLOCK */ \
+ {PAGE_SIZE, PAGE_SIZE}, /* RLIMIT_MEMLOCK */ \
{LONG_MAX, LONG_MAX}, /* RLIMIT_LOCKS */ \
{MAX_SIGPENDING, MAX_SIGPENDING}, /* RLIMIT_SIGPENDING */ \
{MQ_BYTES_MAX, MQ_BYTES_MAX}, /* RLIMIT_MSGQUEUE */ \
--- linux-2.6.8-rc2/include/asm-i386/resource.h.mlock 2004-07-18 00:59:32.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-i386/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -40,7 +40,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING }, \
--- linux-2.6.8-rc2/include/asm-h8300/resource.h.mlock 2004-07-18 00:57:40.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-h8300/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -39,7 +39,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING }, \
--- linux-2.6.8-rc2/include/asm-s390/resource.h.mlock 2004-07-18 00:58:13.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-s390/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -47,7 +47,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING }, \
--- linux-2.6.8-rc2/include/asm-cris/resource.h.mlock 2004-07-18 00:58:54.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-cris/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -39,7 +39,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING }, \
--- linux-2.6.8-rc2/include/asm-sparc64/resource.h.mlock 2004-07-18 00:57:38.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-sparc64/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -43,7 +43,7 @@
{ 0, RLIM_INFINITY}, \
{RLIM_INFINITY, RLIM_INFINITY}, \
{INR_OPEN, INR_OPEN}, {0, 0}, \
- {RLIM_INFINITY, RLIM_INFINITY}, \
+ {PAGE_SIZE, PAGE_SIZE }, \
{RLIM_INFINITY, RLIM_INFINITY}, \
{RLIM_INFINITY, RLIM_INFINITY}, \
{MAX_SIGPENDING, MAX_SIGPENDING}, \
--- linux-2.6.8-rc2/include/asm-arm26/resource.h.mlock 2004-07-18 00:57:38.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-arm26/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -39,7 +39,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING}, \
--- linux-2.6.8-rc2/include/asm-sh/resource.h.mlock 2004-07-18 00:58:54.000000000 -0400
+++ linux-2.6.8-rc2/include/asm-sh/resource.h 2004-08-04 13:25:33.000000000 -0400
@@ -39,7 +39,7 @@
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ 0, 0 }, \
{ INR_OPEN, INR_OPEN }, \
- { RLIM_INFINITY, RLIM_INFINITY }, \
+ { PAGE_SIZE, PAGE_SIZE }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ RLIM_INFINITY, RLIM_INFINITY }, \
{ MAX_SIGPENDING, MAX_SIGPENDING }, \
--- linux-2.6.8-rc2/fs/hugetlbfs/inode.c.mlock 2004-08-04 13:23:11.000000000 -0400
+++ linux-2.6.8-rc2/fs/hugetlbfs/inode.c 2004-08-04 13:27:11.000000000 -0400
@@ -742,7 +742,7 @@ static int can_do_hugetlb_shm(void)

struct file *hugetlb_zero_setup(size_t size)
{
- int error;
+ int error = -ENOMEM;
struct file *file;
struct inode *inode;
struct dentry *dentry, *root;
@@ -755,6 +755,9 @@ struct file *hugetlb_zero_setup(size_t s
if (!is_hugepage_mem_enough(size))
return ERR_PTR(-ENOMEM);

+ if (!user_can_mlock(size, current->user))
+ return ERR_PTR(-ENOMEM);
+
root = hugetlbfs_vfsmount->mnt_root;
snprintf(buf, 16, "%lu", hugetlbfs_counter());
quick_string.name = buf;
@@ -762,7 +765,7 @@ struct file *hugetlb_zero_setup(size_t s
quick_string.hash = 0;
dentry = d_alloc(root, &quick_string);
if (!dentry)
- return ERR_PTR(-ENOMEM);
+ goto out_subtract_mlock;

error = -ENFILE;
file = get_empty_filp();
@@ -789,6 +792,8 @@ out_file:
put_filp(file);
out_dentry:
dput(dentry);
+out_subtract_mlock:
+ user_subtract_mlock(size, current->user);
return ERR_PTR(error);
}

--- linux-2.6.8-rc2/kernel/user.c.mlock 2004-07-18 00:58:20.000000000 -0400
+++ linux-2.6.8-rc2/kernel/user.c 2004-08-04 13:25:33.000000000 -0400
@@ -32,7 +32,8 @@ struct user_struct root_user = {
.processes = ATOMIC_INIT(1),
.files = ATOMIC_INIT(0),
.sigpending = ATOMIC_INIT(0),
- .mq_bytes = 0
+ .mq_bytes = 0,
+ .locked_shm = 0
};

/*
@@ -113,6 +114,7 @@ struct user_struct * alloc_uid(uid_t uid
atomic_set(&new->sigpending, 0);

new->mq_bytes = 0;
+ new->locked_shm = 0;

/*
* Before adding this, check whether we raced
--- linux-2.6.8-rc2/ipc/shm.c.mlock 2004-08-04 13:23:18.000000000 -0400
+++ linux-2.6.8-rc2/ipc/shm.c 2004-08-04 13:25:33.000000000 -0400
@@ -114,7 +114,10 @@ static void shm_destroy (struct shmid_ke
shm_rmid (shp->id);
shm_unlock(shp);
if (!is_file_hugepages(shp->shm_file))
- shmem_lock(shp->shm_file, 0);
+ shmem_lock(shp->shm_file, 0, shp->mlock_user);
+ else
+ user_subtract_mlock(shp->shm_file->f_dentry->d_inode->i_size,
+ shp->mlock_user);
fput (shp->shm_file);
security_shm_free(shp);
ipc_rcu_putref(shp);
@@ -190,6 +193,7 @@ static int newseg (key_t key, int shmflg

shp->shm_perm.key = key;
shp->shm_flags = (shmflg & S_IRWXUGO);
+ shp->mlock_user = NULL;

shp->shm_perm.security = NULL;
error = security_shm_alloc(shp);
@@ -198,9 +202,11 @@ static int newseg (key_t key, int shmflg
return error;
}

- if (shmflg & SHM_HUGETLB)
+ if (shmflg & SHM_HUGETLB) {
+ /* hugetlb_zero_setup takes care of mlock user accounting */
file = hugetlb_zero_setup(size);
- else {
+ shp->mlock_user = current->user;
+ } else {
sprintf (name, "SYSV%08x", key);
file = shmem_file_setup(name, size, VM_ACCOUNT);
}
@@ -504,14 +510,11 @@ asmlinkage long sys_shmctl (int shmid, i
case SHM_LOCK:
case SHM_UNLOCK:
{
-/* Allow superuser to lock segment in memory */
-/* Should the pages be faulted in here or leave it to user? */
-/* need to determine interaction with current->swappable */
- if (!capable(CAP_IPC_LOCK)) {
+ /* Allow superuser to lock segment in memory */
+ if (!can_do_mlock() && cmd == SHM_LOCK) {
err = -EPERM;
goto out;
}
-
shp = shm_lock(shmid);
if(shp==NULL) {
err = -EINVAL;
@@ -526,13 +529,18 @@ asmlinkage long sys_shmctl (int shmid, i
goto out_unlock;

if(cmd==SHM_LOCK) {
- if (!is_file_hugepages(shp->shm_file))
- shmem_lock(shp->shm_file, 1);
- shp->shm_flags |= SHM_LOCKED;
- } else {
- if (!is_file_hugepages(shp->shm_file))
- shmem_lock(shp->shm_file, 0);
+ struct user_struct * user = current->user;
+ if (!is_file_hugepages(shp->shm_file)) {
+ err = shmem_lock(shp->shm_file, 1, current->user);
+ if (!err) {
+ shp->shm_flags |= SHM_LOCKED;
+ shp->mlock_user = user;
+ }
+ }
+ } else if (!is_file_hugepages(shp->shm_file)) {
+ shmem_lock(shp->shm_file, 0, shp->mlock_user);
shp->shm_flags &= ~SHM_LOCKED;
+ shp->mlock_user = NULL;
}
shm_unlock(shp);
goto out;
--- linux-2.6.8-rc2/mm/mlock.c.mlock 2004-07-18 00:57:40.000000000 -0400
+++ linux-2.6.8-rc2/mm/mlock.c 2004-08-04 13:25:33.000000000 -0400
@@ -60,7 +60,7 @@ static int do_mlock(unsigned long start,
struct vm_area_struct * vma, * next;
int error;

- if (on && !capable(CAP_IPC_LOCK))
+ if (on && !can_do_mlock())
return -EPERM;
len = PAGE_ALIGN(len);
end = start + len;
@@ -118,7 +118,7 @@ asmlinkage long sys_mlock(unsigned long
lock_limit >>= PAGE_SHIFT;

/* check against resource limits */
- if (locked <= lock_limit)
+ if ( (locked <= lock_limit) || capable(CAP_IPC_LOCK))
error = do_mlock(start, len, 1);
up_write(&current->mm->mmap_sem);
return error;
@@ -142,7 +142,7 @@ static int do_mlockall(int flags)
unsigned int def_flags;
struct vm_area_struct * vma;

- if (!capable(CAP_IPC_LOCK))
+ if (!can_do_mlock())
return -EPERM;

def_flags = 0;
@@ -177,7 +177,7 @@ asmlinkage long sys_mlockall(int flags)
lock_limit >>= PAGE_SHIFT;

ret = -ENOMEM;
- if (current->mm->total_vm <= lock_limit)
+ if ((current->mm->total_vm <= lock_limit) || capable(CAP_IPC_LOCK))
ret = do_mlockall(flags);
out:
up_write(&current->mm->mmap_sem);
@@ -193,3 +193,36 @@ asmlinkage long sys_munlockall(void)
up_write(&current->mm->mmap_sem);
return ret;
}
+
+/*
+ * Objects with different lifetime than processes (mlocked shm segments
+ * and hugetlb files) get accounted against the user_struct instead.
+ */
+static spinlock_t mlock_user_lock = SPIN_LOCK_UNLOCKED;
+
+int user_can_mlock(size_t size, struct user_struct * user)
+{
+ unsigned long lock_limit, locked;
+ int allowed = 0;
+
+ spin_lock(&mlock_user_lock);
+ locked = size >> PAGE_SHIFT;
+ lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit >>= PAGE_SHIFT;
+ if (locked + user->locked_shm > lock_limit)
+ goto out;
+ get_uid(user);
+ user->locked_shm += locked;
+ allowed = 1;
+out:
+ spin_unlock(&mlock_user_lock);
+ return allowed;
+}
+
+void user_subtract_mlock(size_t size, struct user_struct * user)
+{
+ spin_lock(&mlock_user_lock);
+ user->locked_shm -= (size >> PAGE_SHIFT);
+ spin_unlock(&mlock_user_lock);
+ free_uid(user);
+}
--- linux-2.6.8-rc2/mm/mmap.c.mlock 2004-08-04 13:23:18.000000000 -0400
+++ linux-2.6.8-rc2/mm/mmap.c 2004-08-04 13:25:33.000000000 -0400
@@ -796,15 +796,17 @@ unsigned long do_mmap_pgoff(struct file
mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;

if (flags & MAP_LOCKED) {
- if (!capable(CAP_IPC_LOCK))
+ if (!can_do_mlock())
return -EPERM;
vm_flags |= VM_LOCKED;
}
/* mlock MCL_FUTURE? */
if (vm_flags & VM_LOCKED) {
- unsigned long locked = mm->locked_vm << PAGE_SHIFT;
+ unsigned long locked, lock_limit;
+ locked = mm->locked_vm << PAGE_SHIFT;
+ lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
locked += len;
- if (locked > current->rlim[RLIMIT_MEMLOCK].rlim_cur)
+ if (locked > lock_limit && !capable(CAP_IPC_LOCK))
return -EAGAIN;
}

@@ -1723,9 +1725,11 @@ unsigned long do_brk(unsigned long addr,
* mlock MCL_FUTURE?
*/
if (mm->def_flags & VM_LOCKED) {
- unsigned long locked = mm->locked_vm << PAGE_SHIFT;
+ unsigned long locked, lock_limit;
+ locked = mm->locked_vm << PAGE_SHIFT;
+ lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
locked += len;
- if (locked > current->rlim[RLIMIT_MEMLOCK].rlim_cur)
+ if (locked > lock_limit && !capable(CAP_IPC_LOCK))
return -EAGAIN;
}

--- linux-2.6.8-rc2/mm/mremap.c.mlock 2004-07-18 00:58:37.000000000 -0400
+++ linux-2.6.8-rc2/mm/mremap.c 2004-08-04 13:25:33.000000000 -0400
@@ -324,10 +324,12 @@ unsigned long do_mremap(unsigned long ad
goto out;
}
if (vma->vm_flags & VM_LOCKED) {
- unsigned long locked = current->mm->locked_vm << PAGE_SHIFT;
+ unsigned long locked, lock_limit;
+ locked = current->mm->locked_vm << PAGE_SHIFT;
+ lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
locked += new_len - old_len;
ret = -EAGAIN;
- if (locked > current->rlim[RLIMIT_MEMLOCK].rlim_cur)
+ if (locked > lock_limit && !capable(CAP_IPC_LOCK))
goto out;
}
ret = -ENOMEM;
--- linux-2.6.8-rc2/mm/shmem.c.mlock 2004-08-04 13:23:18.000000000 -0400
+++ linux-2.6.8-rc2/mm/shmem.c 2004-08-04 13:25:33.000000000 -0400
@@ -1151,17 +1151,29 @@ shmem_get_policy(struct vm_area_struct *
}
#endif

-void shmem_lock(struct file *file, int lock)
+int shmem_lock(struct file *file, int lock, struct user_struct * user)
{
struct inode *inode = file->f_dentry->d_inode;
struct shmem_inode_info *info = SHMEM_I(inode);
+ int retval = -ENOMEM;
+
+ if (lock && !can_do_mlock())
+ return -EPERM;

spin_lock(&info->lock);
- if (lock)
+ if (lock && !(info->flags & VM_LOCKED)) {
+ if (!user_can_mlock(inode->i_size, user) && !capable(CAP_IPC_LOCK))
+ goto out_nomem;
info->flags |= VM_LOCKED;
- else
+ }
+ if (!lock && (info->flags & VM_LOCKED) && user) {
+ user_subtract_mlock(inode->i_size, user);
info->flags &= ~VM_LOCKED;
+ }
+ retval = 0;
+out_nomem:
spin_unlock(&info->lock);
+ return retval;
}

static int shmem_mmap(struct file *file, struct vm_area_struct *vma)

-
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