Merge remote branch 'limits/writable_limits'

Conflicts:
	arch/x86/ia32/ia32entry.S
	arch/x86/include/asm/unistd_32.h
	arch/x86/include/asm/unistd_64.h
	arch/x86/kernel/syscall_table_32.S

48 files changed, 451 insertions, 153 deletions

diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
index 599b233bef75..a97f838835ad 100644
--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -2292,7 +2292,7 @@ pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t
 	 * if ((mm->total_vm << PAGE_SHIFT) + len> task->rlim[RLIMIT_AS].rlim_cur)
 	 * 	return -ENOMEM;
 	 */
-	if (size > task->signal->rlim[RLIMIT_MEMLOCK].rlim_cur)
+	if (size > task_rlimit(task, RLIMIT_MEMLOCK))
 		return -ENOMEM;
 
 	/*
diff --git a/arch/ia64/kernel/sys_ia64.c b/arch/ia64/kernel/sys_ia64.c
index 92ed83f34036..b6ba74a83e54 100644
--- a/arch/ia64/kernel/sys_ia64.c
+++ b/arch/ia64/kernel/sys_ia64.c
@@ -129,7 +129,7 @@ ia64_brk (unsigned long brk)
 		goto out;
 
 	/* Check against rlimit.. */
-	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
+	rlim = rlimit(RLIMIT_DATA);
 	if (rlim < RLIM_INFINITY && brk - mm->start_data > rlim)
 		goto out;
 
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 1857766a63c1..dcd8eb739faa 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -91,7 +91,7 @@ dma_mark_clean(void *addr, size_t size)
 inline void
 ia64_set_rbs_bot (void)
 {
-	unsigned long stack_size = current->signal->rlim[RLIMIT_STACK].rlim_max & -16;
+	unsigned long stack_size = rlimit_max(RLIMIT_STACK) & -16;
 
 	if (stack_size > MAX_USER_STACK_SIZE)
 		stack_size = MAX_USER_STACK_SIZE;
diff --git a/arch/powerpc/mm/mmap_64.c b/arch/powerpc/mm/mmap_64.c
index 0d957a4c70fe..5a783d8e8e8e 100644
--- a/arch/powerpc/mm/mmap_64.c
+++ b/arch/powerpc/mm/mmap_64.c
@@ -47,7 +47,7 @@ static inline int mmap_is_legacy(void)
 	if (current->personality & ADDR_COMPAT_LAYOUT)
 		return 1;
 
-	if (current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY)
+	if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
 		return 1;
 
 	return sysctl_legacy_va_layout;
@@ -77,7 +77,7 @@ static unsigned long mmap_rnd(void)
 
 static inline unsigned long mmap_base(void)
 {
-	unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
+	unsigned long gap = rlimit(RLIMIT_STACK);
 
 	if (gap < MIN_GAP)
 		gap = MIN_GAP;
diff --git a/arch/powerpc/platforms/cell/spufs/coredump.c b/arch/powerpc/platforms/cell/spufs/coredump.c
index c4d4a19235e0..eea120229cdb 100644
--- a/arch/powerpc/platforms/cell/spufs/coredump.c
+++ b/arch/powerpc/platforms/cell/spufs/coredump.c
@@ -54,7 +54,7 @@ static ssize_t do_coredump_read(int num, struct spu_context *ctx, void *buffer,
  */
 static int spufs_dump_write(struct file *file, const void *addr, int nr, loff_t *foffset)
 {
-	unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
+	unsigned long limit = rlimit(RLIMIT_CORE);
 	ssize_t written;
 
 	if (*foffset + nr > limit)
diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index f4558ccf02b9..869efbaed3ea 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -40,7 +40,7 @@
 
 static inline unsigned long mmap_base(void)
 {
-	unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
+	unsigned long gap = rlimit(RLIMIT_STACK);
 
 	if (gap < MIN_GAP)
 		gap = MIN_GAP;
@@ -61,7 +61,7 @@ static inline int mmap_is_legacy(void)
 #endif
 	return sysctl_legacy_va_layout ||
 	    (current->personality & ADDR_COMPAT_LAYOUT) ||
-	    current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY;
+	    rlimit(RLIMIT_STACK) == RLIM_INFINITY;
 }
 
 #ifndef CONFIG_64BIT
diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index e2d102447a43..f4392832a9da 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -361,6 +361,7 @@ EXPORT_SYMBOL(get_fb_unmapped_area);
 void arch_pick_mmap_layout(struct mm_struct *mm)
 {
 	unsigned long random_factor = 0UL;
+	unsigned long gap;
 
 	if (current->flags & PF_RANDOMIZE) {
 		random_factor = get_random_int();
@@ -375,9 +376,10 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
 	 * Fall back to the standard layout if the personality
 	 * bit is set, or if the expected stack growth is unlimited:
 	 */
+	gap = rlimit(RLIMIT_STACK);
 	if (!test_thread_flag(TIF_32BIT) ||
 	    (current->personality & ADDR_COMPAT_LAYOUT) ||
-	    current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY ||
+	    gap == RLIM_INFINITY ||
 	    sysctl_legacy_va_layout) {
 		mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
 		mm->get_unmapped_area = arch_get_unmapped_area;
@@ -385,9 +387,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
 	} else {
 		/* We know it's 32-bit */
 		unsigned long task_size = STACK_TOP32;
-		unsigned long gap;
 
-		gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
 		if (gap < 128 * 1024 * 1024)
 			gap = 128 * 1024 * 1024;
 		if (gap > (task_size / 6 * 5))
diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
index 2a4d073d2cf1..06474788723f 100644
--- a/arch/x86/ia32/ia32_aout.c
+++ b/arch/x86/ia32/ia32_aout.c
@@ -297,7 +297,7 @@ static int load_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 	 * size limits imposed on them by creating programs with large
 	 * arrays in the data or bss.
 	 */
-	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
+	rlim = rlimit(RLIMIT_DATA);
 	if (rlim >= RLIM_INFINITY)
 		rlim = ~0;
 	if (ex.a_data + ex.a_bss > rlim)
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index d2e8911c5cf8..f8551f21c4d8 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -844,4 +844,6 @@ ia32_sys_call_table:
 	.quad compat_sys_recvmmsg
 	.quad sys_fanotify_init
 	.quad sys32_fanotify_mark
+	.quad compat_sys_getprlimit		/* 340 */
+	.quad compat_sys_setprlimit
 ia32_syscall_end:
diff --git a/arch/x86/include/asm/unistd_32.h b/arch/x86/include/asm/unistd_32.h
index cf70e9e17dbc..64c7765ea4a1 100644
--- a/arch/x86/include/asm/unistd_32.h
+++ b/arch/x86/include/asm/unistd_32.h
@@ -345,10 +345,12 @@
 #define __NR_recvmmsg		337
 #define __NR_fanotify_init	338
 #define __NR_fanotify_mark	339
+#define __NR_getprlimit		340
+#define __NR_setprlimit		341
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 340
+#define NR_syscalls 342
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/x86/include/asm/unistd_64.h b/arch/x86/include/asm/unistd_64.h
index 7fbd20f943f6..78e2e0bf1394 100644
--- a/arch/x86/include/asm/unistd_64.h
+++ b/arch/x86/include/asm/unistd_64.h
@@ -667,6 +667,10 @@ __SYSCALL(__NR_recvmmsg, sys_recvmmsg)
 __SYSCALL(__NR_fanotify_init, sys_fanotify_init)
 #define __NR_fanotify_mark			301
 __SYSCALL(__NR_fanotify_mark, sys_fanotify_mark)
+#define __NR_getprlimit				302
+__SYSCALL(__NR_getprlimit, sys_getprlimit)
+#define __NR_setprlimit				303
+__SYSCALL(__NR_setprlimit, sys_setprlimit)
 
 #ifndef __NO_STUBS
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/x86/kernel/syscall_table_32.S b/arch/x86/kernel/syscall_table_32.S
index ca486c74897d..2bd2e7f535c7 100644
--- a/arch/x86/kernel/syscall_table_32.S
+++ b/arch/x86/kernel/syscall_table_32.S
@@ -339,3 +339,5 @@ ENTRY(sys_call_table)
 	.long sys_recvmmsg
 	.long sys_fanotify_init
 	.long sys_fanotify_mark
+	.long sys_getprlimit		/* 340 */
+	.long sys_setprlimit
diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
index c8191defc38a..1dab5194fd9d 100644
--- a/arch/x86/mm/mmap.c
+++ b/arch/x86/mm/mmap.c
@@ -71,7 +71,7 @@ static int mmap_is_legacy(void)
 	if (current->personality & ADDR_COMPAT_LAYOUT)
 		return 1;
 
-	if (current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY)
+	if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
 		return 1;
 
 	return sysctl_legacy_va_layout;
@@ -96,7 +96,7 @@ static unsigned long mmap_rnd(void)
 
 static unsigned long mmap_base(void)
 {
-	unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
+	unsigned long gap = rlimit(RLIMIT_STACK);
 
 	if (gap < MIN_GAP)
 		gap = MIN_GAP;
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 6f7c096abf13..4f906f0614f0 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -136,7 +136,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
 	down_write(&current->mm->mmap_sem);
 
 	locked     = npages + current->mm->locked_vm;
-	lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
+	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 
 	if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
 		ret = -ENOMEM;
diff --git a/drivers/infiniband/hw/ipath/ipath_user_pages.c b/drivers/infiniband/hw/ipath/ipath_user_pages.c
index 82878e348627..eb7d59abd12d 100644
--- a/drivers/infiniband/hw/ipath/ipath_user_pages.c
+++ b/drivers/infiniband/hw/ipath/ipath_user_pages.c
@@ -59,8 +59,7 @@ static int __get_user_pages(unsigned long start_page, size_t num_pages,
 	size_t got;
 	int ret;
 
-	lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >>
-		PAGE_SHIFT;
+	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 
 	if (num_pages > lock_limit) {
 		ret = -ENOMEM;
diff --git a/fs/attr.c b/fs/attr.c
index 96d394bdaddf..34ade0e04886 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -82,7 +82,7 @@ int inode_newsize_ok(const struct inode *inode, loff_t offset)
 	if (inode->i_size < offset) {
 		unsigned long limit;
 
-		limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
+		limit = rlimit(RLIMIT_FSIZE);
 		if (limit != RLIM_INFINITY && offset > limit)
 			goto out_sig;
 		if (offset > inode->i_sb->s_maxbytes)
diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
index b639dcf7c778..06d892e21669 100644
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -246,7 +246,7 @@ static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 	 * size limits imposed on them by creating programs with large
 	 * arrays in the data or bss.
 	 */
-	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
+	rlim = rlimit(RLIMIT_DATA);
 	if (rlim >= RLIM_INFINITY)
 		rlim = ~0;
 	if (ex.a_data + ex.a_bss > rlim)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index a2796651e756..b78b9de64514 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -501,7 +501,7 @@ static int load_flat_file(struct linux_binprm * bprm,
 	 * size limits imposed on them by creating programs with large
 	 * arrays in the data or bss.
 	 */
-	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
+	rlim = rlimit(RLIMIT_DATA);
 	if (rlim >= RLIM_INFINITY)
 		rlim = ~0;
 	if (data_len + bss_len > rlim) {
diff --git a/fs/exec.c b/fs/exec.c
index f01cfe94c929..6ae069018761 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -195,7 +195,7 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
 		 *    to work from.
 		 */
 		rlim = current->signal->rlim;
-		if (size > rlim[RLIMIT_STACK].rlim_cur / 4) {
+		if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4) {
 			put_page(page);
 			return NULL;
 		}
@@ -574,7 +574,7 @@ int setup_arg_pages(struct linux_binprm *bprm,
 
 #ifdef CONFIG_STACK_GROWSUP
 	/* Limit stack size to 1GB */
-	stack_base = current->signal->rlim[RLIMIT_STACK].rlim_max;
+	stack_base = rlimit_max(RLIMIT_STACK);
 	if (stack_base > (1 << 30))
 		stack_base = 1 << 30;
 
@@ -1499,7 +1499,7 @@ static int format_corename(char *corename, long signr)
 			/* core limit size */
 			case 'c':
 				rc = snprintf(out_ptr, out_end - out_ptr,
-					      "%lu", current->signal->rlim[RLIMIT_CORE].rlim_cur);
+					      "%lu", rlimit(RLIMIT_CORE));
 				if (rc > out_end - out_ptr)
 					goto out;
 				out_ptr += rc;
@@ -1758,7 +1758,7 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
 	int retval = 0;
 	int flag = 0;
 	int ispipe = 0;
-	unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
+	unsigned long core_limit = rlimit(RLIMIT_CORE);
 	char **helper_argv = NULL;
 	int helper_argc = 0;
 	int dump_count = 0;
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 2cf93ec40a67..09c6271fe26e 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -344,7 +344,7 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
 	switch (cmd) {
 	case F_DUPFD:
 	case F_DUPFD_CLOEXEC:
-		if (arg >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
+		if (arg >= rlimit(RLIMIT_NOFILE))
 			break;
 		err = alloc_fd(arg, cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0);
 		if (err >= 0) {
diff --git a/fs/file.c b/fs/file.c
index 87e129030ab1..d1c21d8e428d 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -257,7 +257,7 @@ int expand_files(struct files_struct *files, int nr)
 	 * N.B. For clone tasks sharing a files structure, this test
 	 * will limit the total number of files that can be opened.
 	 */
-	if (nr >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
+	if (nr >= rlimit(RLIMIT_NOFILE))
 		return -EMFILE;
 
 	/* Do we need to expand? */
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 4badde179b18..2e5c2a34e06e 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -266,7 +266,7 @@ static inline void task_sig(struct seq_file *m, struct task_struct *p)
 		collect_sigign_sigcatch(p, &ignored, &caught);
 		num_threads = atomic_read(&p->signal->count);
 		qsize = atomic_read(&__task_cred(p)->user->sigpending);
-		qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur;
+		qlim = task_rlimit(p, RLIMIT_SIGPENDING);
 		unlock_task_sighand(p, &flags);
 	}
 
@@ -502,7 +502,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
 		cutime = sig->cutime;
 		cstime = sig->cstime;
 		cgtime = sig->cgtime;
-		rsslim = sig->rlim[RLIMIT_RSS].rlim_cur;
+		rsslim = ACCESS_ONCE(sig->rlim[RLIMIT_RSS].rlim_cur);
 
 		/* add up live thread stats at the group level */
 		if (whole) {
diff --git a/fs/proc/base.c b/fs/proc/base.c
index af643b5aefe8..9fdb990fc6d4 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -477,19 +477,30 @@ static const struct limit_names lnames[RLIM_NLIMITS] = {
 };
 
 /* Display limits for a process */
-static int proc_pid_limits(struct task_struct *task, char *buffer)
+static ssize_t limits_read(struct file *file, char __user *buf, size_t rcount,
+		loff_t *ppos)
 {
-	unsigned int i;
-	int count = 0;
-	unsigned long flags;
-	char *bufptr = buffer;
-
 	struct rlimit rlim[RLIM_NLIMITS];
+	struct task_struct *task;
+	unsigned long flags;
+	unsigned int i;
+	ssize_t count = 0;
+	char *bufptr;
 
-	if (!lock_task_sighand(task, &flags))
+	task = get_proc_task(file->f_path.dentry->d_inode);
+	if (!task)
+		return -ESRCH;
+	if (!lock_task_sighand(task, &flags)) {
+		put_task_struct(task);
 		return 0;
+	}
 	memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
 	unlock_task_sighand(task, &flags);
+	put_task_struct(task);
+
+	bufptr = (char *)__get_free_page(GFP_TEMPORARY);
+	if (!bufptr)
+		return -ENOMEM;
 
 	/*
 	 * print the file header
@@ -518,9 +529,81 @@ static int proc_pid_limits(struct task_struct *task, char *buffer)
 			count += sprintf(&bufptr[count], "\n");
 	}
 
+	count = simple_read_from_buffer(buf, rcount, ppos, bufptr, count);
+
+	free_page((unsigned long)bufptr);
+
+	return count;
+}
+
+static ssize_t limits_write(struct file *file, const char __user *buf,
+		size_t count, loff_t *ppos)
+{
+	struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
+	char str[32 + 1 + 16 + 1 + 16 + 1], *delim, *next;
+	struct rlimit new_rlimit;
+	unsigned int i;
+	int ret;
+
+	if (!task) {
+		count = -ESRCH;
+		goto out;
+	}
+	if (copy_from_user(str, buf, min(count, sizeof(str) - 1))) {
+		count = -EFAULT;
+		goto put_task;
+	}
+
+	str[min(count, sizeof(str) - 1)] = 0;
+
+	delim = strchr(str, '=');
+	if (!delim) {
+		count = -EINVAL;
+		goto put_task;
+	}
+	*delim++ = 0; /* for easy 'str' usage */
+	new_rlimit.rlim_cur = simple_strtoul(delim, &next, 0);
+	if (*next != ':') {
+		if (strncmp(delim, "unlimited:", 10)) {
+			count = -EINVAL;
+			goto put_task;
+		}
+		new_rlimit.rlim_cur = RLIM_INFINITY;
+		next = delim + 9; /* move to ':' */
+	}
+	delim = next + 1;
+	new_rlimit.rlim_max = simple_strtoul(delim, &next, 0);
+	if (*next != 0) {
+		if (strcmp(delim, "unlimited")) {
+			count = -EINVAL;
+			goto put_task;
+		}
+		new_rlimit.rlim_max = RLIM_INFINITY;
+	}
+
+	for (i = 0; i < RLIM_NLIMITS; i++)
+		if (!strcmp(str, lnames[i].name))
+			break;
+	if (i >= RLIM_NLIMITS) {
+		count = -EINVAL;
+		goto put_task;
+	}
+
+	ret = do_setrlimit(task, i, &new_rlimit);
+	if (ret)
+		count = ret;
+
+put_task:
+	put_task_struct(task);
+out:
 	return count;
 }
 
+static const struct file_operations proc_pid_limits_operations = {
+	.read	= limits_read,
+	.write	= limits_write,
+};
+
 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
 static int proc_pid_syscall(struct task_struct *task, char *buffer)
 {
@@ -2500,7 +2583,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 	INF("auxv",       S_IRUSR, proc_pid_auxv),
 	ONE("status",     S_IRUGO, proc_pid_status),
 	ONE("personality", S_IRUSR, proc_pid_personality),
-	INF("limits",	  S_IRUSR, proc_pid_limits),
+	REG("limits",	  S_IRUSR|S_IWUSR, proc_pid_limits_operations),
 #ifdef CONFIG_SCHED_DEBUG
 	REG("sched",      S_IRUGO|S_IWUSR, proc_pid_sched_operations),
 #endif
@@ -2834,7 +2917,7 @@ static const struct pid_entry tid_base_stuff[] = {
 	INF("auxv",      S_IRUSR, proc_pid_auxv),
 	ONE("status",    S_IRUGO, proc_pid_status),
 	ONE("personality", S_IRUSR, proc_pid_personality),
-	INF("limits",	 S_IRUSR, proc_pid_limits),
+	REG("limits",	  S_IRUSR|S_IWUSR, proc_pid_limits_operations),
 #ifdef CONFIG_SCHED_DEBUG
 	REG("sched",     S_IRUGO|S_IWUSR, proc_pid_sched_operations),
 #endif
diff --git a/fs/select.c b/fs/select.c
index fd38ce2e32e3..73715e90030f 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -821,7 +821,7 @@ int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds,
  	struct poll_list *walk = head;
  	unsigned long todo = nfds;
 
-	if (nfds > current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
+	if (nfds > rlimit(RLIMIT_NOFILE))
 		return -EINVAL;
 
 	len = min_t(unsigned int, nfds, N_STACK_PPS);
diff --git a/include/asm-generic/unistd.h b/include/asm-generic/unistd.h
index 7c38c147e5e6..0b3ea8bc4e3b 100644
--- a/include/asm-generic/unistd.h
+++ b/include/asm-generic/unistd.h
@@ -622,9 +622,13 @@ __SYSCALL(__NR_move_pages, sys_move_pages)
 __SYSCALL(__NR_rt_tgsigqueueinfo, sys_rt_tgsigqueueinfo)
 #define __NR_perf_event_open 241
 __SYSCALL(__NR_perf_event_open, sys_perf_event_open)
+#define __NR_getprlimit 242
+__SYSCALL(__NR_getprlimit, sys_getprlimit)
+#define __NR_setprlimit 243
+__SYSCALL(__NR_setprlimit, sys_setprlimit)
 
 #undef __NR_syscalls
-#define __NR_syscalls 242
+#define __NR_syscalls 244
 
 /*
  * All syscalls below here should go away really,
diff --git a/include/linux/Kbuild b/include/linux/Kbuild
index 24f050d2893c..dbee58e4d60d 100644
--- a/include/linux/Kbuild
+++ b/include/linux/Kbuild
@@ -141,7 +141,6 @@ header-y += qnxtypes.h
 header-y += qnx4_fs.h
 header-y += radeonfb.h
 header-y += raw.h
-header-y += resource.h
 header-y += romfs_fs.h
 header-y += rose.h
 header-y += serial_reg.h
@@ -326,6 +325,7 @@ unifdef-y += irqnr.h
 unifdef-y += reboot.h
 unifdef-y += reiserfs_fs.h
 unifdef-y += reiserfs_xattr.h
+unifdef-y += resource.h
 unifdef-y += route.h
 unifdef-y += rtc.h
 unifdef-y += rtnetlink.h
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 4f71bf4e628c..3e23844a6990 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -117,6 +117,6 @@ void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
 
 long clock_nanosleep_restart(struct restart_block *restart_block);
 
-void update_rlimit_cpu(unsigned long rlim_new);
+void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);
 
 #endif
diff --git a/include/linux/resource.h b/include/linux/resource.h
index 40fc7e626082..cf8dc96653ee 100644
--- a/include/linux/resource.h
+++ b/include/linux/resource.h
@@ -3,8 +3,6 @@
 
 #include <linux/time.h>
 
-struct task_struct;
-
 /*
  * Resource control/accounting header file for linux
  */
@@ -70,6 +68,14 @@ struct rlimit {
  */
 #include <asm/resource.h>
 
+#ifdef __KERNEL__
+
+struct task_struct;
+
 int getrusage(struct task_struct *p, int who, struct rusage __user *ru);
+int do_setrlimit(struct task_struct *tsk, unsigned int resource,
+		struct rlimit *new_rlim);
+
+#endif /* __KERNEL__ */
 
 #endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 89115ec7d43f..9521759b8fc8 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2585,6 +2585,28 @@ static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
 }
 #endif /* CONFIG_MM_OWNER */
 
+static inline unsigned long task_rlimit(const struct task_struct *tsk,
+		unsigned int limit)
+{
+	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
+}
+
+static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
+		unsigned int limit)
+{
+	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
+}
+
+static inline unsigned long rlimit(unsigned int limit)
+{
+	return task_rlimit(current, limit);
+}
+
+static inline unsigned long rlimit_max(unsigned int limit)
+{
+	return task_rlimit_max(current, limit);
+}
+
 #define TASK_STATE_TO_CHAR_STR "RSDTtZX"
 
 #endif /* __KERNEL__ */
diff --git a/include/linux/security.h b/include/linux/security.h
index 466cbadbd1ef..9c3a43b20ce7 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1591,7 +1591,8 @@ struct security_operations {
 	int (*task_setnice) (struct task_struct *p, int nice);
 	int (*task_setioprio) (struct task_struct *p, int ioprio);
 	int (*task_getioprio) (struct task_struct *p);
-	int (*task_setrlimit) (unsigned int resource, struct rlimit *new_rlim);
+	int (*task_setrlimit) (struct task_struct *p, unsigned int resource,
+			struct rlimit *new_rlim);
 	int (*task_setscheduler) (struct task_struct *p, int policy,
 				  struct sched_param *lp);
 	int (*task_getscheduler) (struct task_struct *p);
@@ -1856,7 +1857,8 @@ int security_task_setgroups(struct group_info *group_info);
 int security_task_setnice(struct task_struct *p, int nice);
 int security_task_setioprio(struct task_struct *p, int ioprio);
 int security_task_getioprio(struct task_struct *p);
-int security_task_setrlimit(unsigned int resource, struct rlimit *new_rlim);
+int security_task_setrlimit(struct task_struct *p, unsigned int resource,
+		struct rlimit *new_rlim);
 int security_task_setscheduler(struct task_struct *p,
 				int policy, struct sched_param *lp);
 int security_task_getscheduler(struct task_struct *p);
@@ -2472,7 +2474,8 @@ static inline int security_task_getioprio(struct task_struct *p)
 	return 0;
 }
 
-static inline int security_task_setrlimit(unsigned int resource,
+static inline int security_task_setrlimit(struct task_struct *p,
+					  unsigned int resource,
 					  struct rlimit *new_rlim)
 {
 	return 0;
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 79d82d1f3c0b..c22067006ffa 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -657,11 +657,15 @@ asmlinkage long sys_newuname(struct new_utsname __user *name);
 
 asmlinkage long sys_getrlimit(unsigned int resource,
 				struct rlimit __user *rlim);
+asmlinkage long sys_getprlimit(pid_t pid, unsigned int resource,
+				struct rlimit __user *rlim);
 #if defined(COMPAT_RLIM_OLD_INFINITY) || !(defined(CONFIG_IA64))
 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim);
 #endif
 asmlinkage long sys_setrlimit(unsigned int resource,
 				struct rlimit __user *rlim);
+asmlinkage long sys_setprlimit(pid_t pid, unsigned int resource,
+				struct rlimit __user *rlim);
 asmlinkage long sys_getrusage(int who, struct rusage __user *ru);
 asmlinkage long sys_umask(int mask);
 
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index ee9d69707c0a..f5d4bd25a83d 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -153,7 +153,7 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
 			spin_lock(&mq_lock);
 			if (u->mq_bytes + mq_bytes < u->mq_bytes ||
 		 	    u->mq_bytes + mq_bytes >
-			    p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) {
+			    task_rlimit(p, RLIMIT_MSGQUEUE)) {
 				spin_unlock(&mq_lock);
 				goto out_inode;
 			}
diff --git a/ipc/shm.c b/ipc/shm.c
index 464694e0aa4a..757f5967b39b 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -761,8 +761,7 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 			if (euid != shp->shm_perm.uid &&
 			    euid != shp->shm_perm.cuid)
 				goto out_unlock;
-			if (cmd == SHM_LOCK &&
-			    !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur)
+			if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK))
 				goto out_unlock;
 		}
 
diff --git a/kernel/compat.c b/kernel/compat.c
index f6c204f07ea6..c1d57043676b 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -274,6 +274,39 @@ asmlinkage long compat_sys_sigprocmask(int how, compat_old_sigset_t __user *set,
 	return ret;
 }
 
+static int get_compat_rlimit(struct rlimit *dst,
+		const struct compat_rlimit __user *src)
+{
+	if (!access_ok(VERIFY_READ, src, sizeof(*src)) ||
+			__get_user(dst->rlim_cur, &src->rlim_cur) ||
+			__get_user(dst->rlim_max, &src->rlim_max))
+		return -EFAULT;
+
+	if (dst->rlim_cur == COMPAT_RLIM_INFINITY)
+		dst->rlim_cur = RLIM_INFINITY;
+	if (dst->rlim_max == COMPAT_RLIM_INFINITY)
+		dst->rlim_max = RLIM_INFINITY;
+	return 0;
+}
+
+static int put_compat_rlimit(const struct rlimit *src,
+		struct compat_rlimit __user *dst)
+{
+	struct rlimit r = *src;
+
+	if (r.rlim_cur > COMPAT_RLIM_INFINITY)
+		r.rlim_cur = COMPAT_RLIM_INFINITY;
+	if (r.rlim_max > COMPAT_RLIM_INFINITY)
+		r.rlim_max = COMPAT_RLIM_INFINITY;
+
+	if (!access_ok(VERIFY_WRITE, dst, sizeof(*dst)) ||
+	    __put_user(r.rlim_cur, &dst->rlim_cur) ||
+	    __put_user(r.rlim_max, &dst->rlim_max))
+		return -EFAULT;
+
+	return 0;
+}
+
 asmlinkage long compat_sys_setrlimit(unsigned int resource,
 		struct compat_rlimit __user *rlim)
 {
@@ -284,17 +317,12 @@ asmlinkage long compat_sys_setrlimit(unsigned int resource,
 	if (resource >= RLIM_NLIMITS)
 		return -EINVAL;
 
-	if (!access_ok(VERIFY_READ, rlim, sizeof(*rlim)) ||
-	    __get_user(r.rlim_cur, &rlim->rlim_cur) ||
-	    __get_user(r.rlim_max, &rlim->rlim_max))
-		return -EFAULT;
+	ret = get_compat_rlimit(&r, rlim);
+	if (ret)
+		return ret;
 
-	if (r.rlim_cur == COMPAT_RLIM_INFINITY)
-		r.rlim_cur = RLIM_INFINITY;
-	if (r.rlim_max == COMPAT_RLIM_INFINITY)
-		r.rlim_max = RLIM_INFINITY;
 	set_fs(KERNEL_DS);
-	ret = sys_setrlimit(resource, (struct rlimit __user *) &r);
+	ret = sys_setrlimit(resource, (struct rlimit __force __user *)&r);
 	set_fs(old_fs);
 	return ret;
 }
@@ -336,19 +364,42 @@ asmlinkage long compat_sys_getrlimit (unsigned int resource,
 	mm_segment_t old_fs = get_fs();
 
 	set_fs(KERNEL_DS);
-	ret = sys_getrlimit(resource, (struct rlimit __user *) &r);
+	ret = sys_getrlimit(resource, (struct rlimit __force __user *)&r);
 	set_fs(old_fs);
-	if (!ret) {
-		if (r.rlim_cur > COMPAT_RLIM_INFINITY)
-			r.rlim_cur = COMPAT_RLIM_INFINITY;
-		if (r.rlim_max > COMPAT_RLIM_INFINITY)
-			r.rlim_max = COMPAT_RLIM_INFINITY;
+	if (!ret)
+		ret = put_compat_rlimit(&r, rlim);
+	return ret;
+}
 
-		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
-		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
-		    __put_user(r.rlim_max, &rlim->rlim_max))
-			return -EFAULT;
-	}
+asmlinkage long compat_sys_setprlimit(pid_t pid, unsigned int resource,
+		struct compat_rlimit __user *rlim)
+{
+	mm_segment_t old_fs = get_fs();
+	struct rlimit r;
+	int ret;
+
+	ret = get_compat_rlimit(&r, rlim);
+	if (ret)
+		return ret;
+
+	set_fs(KERNEL_DS);
+	ret = sys_setprlimit(pid, resource, (struct rlimit __force __user *)&r);
+	set_fs(old_fs);
+	return ret;
+}
+
+asmlinkage long compat_sys_getprlimit(pid_t pid, unsigned int resource,
+		struct compat_rlimit __user *rlim)
+{
+	mm_segment_t old_fs = get_fs();
+	struct rlimit r;
+	int ret;
+
+	set_fs(KERNEL_DS);
+	ret = sys_getprlimit(pid, resource, (struct rlimit __force __user *)&r);
+	set_fs(old_fs);
+	if (!ret)
+		ret = put_compat_rlimit(&r, rlim);
 	return ret;
 }
 
diff --git a/kernel/fork.c b/kernel/fork.c
index 1415dc4598ae..f3885e71bf0c 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -824,6 +824,8 @@ void __cleanup_sighand(struct sighand_struct *sighand)
  */
 static void posix_cpu_timers_init_group(struct signal_struct *sig)
 {
+	unsigned long cpu_limit;
+
 	/* Thread group counters. */
 	thread_group_cputime_init(sig);
 
@@ -838,9 +840,9 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig)
 	sig->cputime_expires.virt_exp = cputime_zero;
 	sig->cputime_expires.sched_exp = 0;
 
-	if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
-		sig->cputime_expires.prof_exp =
-			secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
+	cpu_limit = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
+	if (cpu_limit != RLIM_INFINITY) {
+		sig->cputime_expires.prof_exp = secs_to_cputime(cpu_limit);
 		sig->cputimer.running = 1;
 	}
 
@@ -1033,7 +1035,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 #endif
 	retval = -EAGAIN;
 	if (atomic_read(&p->real_cred->user->processes) >=
-			p->signal->rlim[RLIMIT_NPROC].rlim_cur) {
+			task_rlimit(p, RLIMIT_NPROC)) {
 		if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
 		    p->real_cred->user != INIT_USER)
 			goto bad_fork_free;
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 82224c19342e..309cec534dd8 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2457,7 +2457,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
 	if (user_locked > user_lock_limit)
 		extra = user_locked - user_lock_limit;
 
-	lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+	lock_limit = rlimit(RLIMIT_MEMLOCK);
 	lock_limit >>= PAGE_SHIFT;
 	locked = vma->vm_mm->locked_vm + extra;
 
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 438ff4523513..5bd038c313e9 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -13,16 +13,16 @@
 /*
  * Called after updating RLIMIT_CPU to set timer expiration if necessary.
  */
-void update_rlimit_cpu(unsigned long rlim_new)
+void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
 {
 	cputime_t cputime = secs_to_cputime(rlim_new);
-	struct signal_struct *const sig = current->signal;
+	struct signal_struct *const sig = task->signal;
 
 	if (cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) ||
 	    cputime_gt(sig->it[CPUCLOCK_PROF].expires, cputime)) {
-		spin_lock_irq(&current->sighand->siglock);
-		set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
-		spin_unlock_irq(&current->sighand->siglock);
+		spin_lock_irq(&task->sighand->siglock);
+		set_process_cpu_timer(task, CPUCLOCK_PROF, &cputime, NULL);
+		spin_unlock_irq(&task->sighand->siglock);
 	}
 }
 
@@ -639,7 +639,7 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
 				if (expires_le(sig->it[CPUCLOCK_PROF].expires,
 					       exp->cpu))
 					break;
-				i = sig->rlim[RLIMIT_CPU].rlim_cur;
+				i = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
 				if (i != RLIM_INFINITY &&
 				    i <= cputime_to_secs(exp->cpu))
 					break;
@@ -982,6 +982,7 @@ static void check_thread_timers(struct task_struct *tsk,
 	int maxfire;
 	struct list_head *timers = tsk->cpu_timers;
 	struct signal_struct *const sig = tsk->signal;
+	unsigned long soft;
 
 	maxfire = 20;
 	tsk->cputime_expires.prof_exp = cputime_zero;
@@ -1030,9 +1031,10 @@ static void check_thread_timers(struct task_struct *tsk,
 	/*
 	 * Check for the special case thread timers.
 	 */
-	if (sig->rlim[RLIMIT_RTTIME].rlim_cur != RLIM_INFINITY) {
-		unsigned long hard = sig->rlim[RLIMIT_RTTIME].rlim_max;
-		unsigned long *soft = &sig->rlim[RLIMIT_RTTIME].rlim_cur;
+	soft = ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur);
+	if (soft != RLIM_INFINITY) {
+		unsigned long hard = ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].
+				rlim_max);
 
 		if (hard != RLIM_INFINITY &&
 		    tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
@@ -1043,14 +1045,13 @@ static void check_thread_timers(struct task_struct *tsk,
 			__group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
 			return;
 		}
-		if (tsk->rt.timeout > DIV_ROUND_UP(*soft, USEC_PER_SEC/HZ)) {
+		if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) {
 			/*
 			 * At the soft limit, send a SIGXCPU every second.
 			 */
-			if (sig->rlim[RLIMIT_RTTIME].rlim_cur
-			    < sig->rlim[RLIMIT_RTTIME].rlim_max) {
-				sig->rlim[RLIMIT_RTTIME].rlim_cur +=
-								USEC_PER_SEC;
+			if (soft < hard) {
+				soft += USEC_PER_SEC;
+				sig->rlim[RLIMIT_RTTIME].rlim_cur = soft;
 			}
 			printk(KERN_INFO
 				"RT Watchdog Timeout: %s[%d]\n",
@@ -1121,13 +1122,14 @@ static void check_process_timers(struct task_struct *tsk,
 	unsigned long long sum_sched_runtime, sched_expires;
 	struct list_head *timers = sig->cpu_timers;
 	struct task_cputime cputime;
+	unsigned long cpu_cur_lim = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
 
 	/*
 	 * Don't sample the current process CPU clocks if there are no timers.
 	 */
 	if (list_empty(&timers[CPUCLOCK_PROF]) &&
 	    cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) &&
-	    sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY &&
+	    cpu_cur_lim == RLIM_INFINITY &&
 	    list_empty(&timers[CPUCLOCK_VIRT]) &&
 	    cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) &&
 	    list_empty(&timers[CPUCLOCK_SCHED])) {
@@ -1194,10 +1196,12 @@ static void check_process_timers(struct task_struct *tsk,
 	check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
 			 SIGVTALRM);
 
-	if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
+	if (cpu_cur_lim != RLIM_INFINITY) {
 		unsigned long psecs = cputime_to_secs(ptime);
+		unsigned long hard =
+			ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_max);
 		cputime_t x;
-		if (psecs >= sig->rlim[RLIMIT_CPU].rlim_max) {
+		if (psecs >= hard) {
 			/*
 			 * At the hard limit, we just die.
 			 * No need to calculate anything else now.
@@ -1205,17 +1209,17 @@ static void check_process_timers(struct task_struct *tsk,
 			__group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
 			return;
 		}
-		if (psecs >= sig->rlim[RLIMIT_CPU].rlim_cur) {
+		if (psecs >= cpu_cur_lim) {
 			/*
 			 * At the soft limit, send a SIGXCPU every second.
 			 */
 			__group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
-			if (sig->rlim[RLIMIT_CPU].rlim_cur
-			    < sig->rlim[RLIMIT_CPU].rlim_max) {
-				sig->rlim[RLIMIT_CPU].rlim_cur++;
+			if (cpu_cur_lim < hard) {
+				cpu_cur_lim++;
+				sig->rlim[RLIMIT_CPU].rlim_cur = cpu_cur_lim;
 			}
 		}
-		x = secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
+		x = secs_to_cputime(cpu_cur_lim);
 		if (cputime_eq(prof_expires, cputime_zero) ||
 		    cputime_lt(x, prof_expires)) {
 			prof_expires = x;
@@ -1382,7 +1386,7 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
 			return 1;
 	}
 
-	return sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY;
+	return ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur) != RLIM_INFINITY;
 }
 
 /*
@@ -1480,7 +1484,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
 		 * If the RLIMIT_CPU timer will expire before the
 		 * ITIMER_PROF timer, we have nothing else to do.
 		 */
-		if (tsk->signal->rlim[RLIMIT_CPU].rlim_cur
+		if (task_rlimit(tsk, RLIMIT_CPU)
 		    < cputime_to_secs(*newval))
 			return;
 	}
diff --git a/kernel/sched.c b/kernel/sched.c
index e7f2cfa6a257..11d7a009cff0 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6118,7 +6118,7 @@ int can_nice(const struct task_struct *p, const int nice)
 	/* convert nice value [19,-20] to rlimit style value [1,40] */
 	int nice_rlim = 20 - nice;
 
-	return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur ||
+	return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) ||
 		capable(CAP_SYS_NICE));
 }
 
@@ -6295,7 +6295,7 @@ recheck:
 
 			if (!lock_task_sighand(p, &flags))
 				return -ESRCH;
-			rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur;
+			rlim_rtprio = task_rlimit(p, RLIMIT_RTPRIO);
 			unlock_task_sighand(p, &flags);
 
 			/* can't set/change the rt policy */
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 5c5fef378415..b065ada8e8d2 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1670,8 +1670,9 @@ static void watchdog(struct rq *rq, struct task_struct *p)
 	if (!p->signal)
 		return;
 
-	soft = p->signal->rlim[RLIMIT_RTTIME].rlim_cur;
-	hard = p->signal->rlim[RLIMIT_RTTIME].rlim_max;
+	/* max may change after cur was read, this will be fixed next tick */
+	soft = task_rlimit(p, RLIMIT_RTTIME);
+	hard = task_rlimit_max(p, RLIMIT_RTTIME);
 
 	if (soft != RLIM_INFINITY) {
 		unsigned long next;
diff --git a/kernel/signal.c b/kernel/signal.c
index 6b982f2cf524..e16f3a04ea1d 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -228,7 +228,7 @@ __sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimi
 
 	if (override_rlimit ||
 	    atomic_read(&user->sigpending) <=
-			t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) {
+			task_rlimit(t, RLIMIT_SIGPENDING)) {
 		q = kmem_cache_alloc(sigqueue_cachep, flags);
 	} else {
 		print_dropped_signal(sig);
diff --git a/kernel/sys.c b/kernel/sys.c
index 585d6cd10040..98be1a2d7c55 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -572,8 +572,7 @@ static int set_user(struct cred *new)
 		return -EINVAL;
 	}
 
-	if (atomic_read(&new_user->processes) >=
-				current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
+	if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
 			new_user != INIT_USER) {
 		free_uid(new_user);
 		return -EAGAIN;
@@ -1212,6 +1211,61 @@ SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
 	}
 }
 
+static int check_prlimit_permission(struct task_struct *task)
+{
+	const struct cred *cred = current_cred(), *tcred;
+	int ret = 0;
+
+	rcu_read_lock();
+	tcred = __task_cred(task);
+	if ((cred->uid != tcred->euid ||
+	     cred->uid != tcred->suid ||
+	     cred->uid != tcred->uid  ||
+	     cred->gid != tcred->egid ||
+	     cred->gid != tcred->sgid ||
+	     cred->gid != tcred->gid) &&
+	     !capable(CAP_SYS_RESOURCE)) {
+		ret = -EPERM;
+	}
+	rcu_read_unlock();
+	return ret;
+}
+
+SYSCALL_DEFINE3(getprlimit, pid_t, pid, unsigned int, resource,
+		struct rlimit __user *, rlim)
+{
+	struct rlimit val;
+	struct task_struct *tsk;
+	int ret;
+
+	if (resource >= RLIM_NLIMITS)
+		return -EINVAL;
+
+	read_lock(&tasklist_lock);
+
+	tsk = find_task_by_vpid(pid);
+	if (!tsk || !tsk->sighand) {
+		ret = -ESRCH;
+		goto err_unlock;
+	}
+
+	ret = check_prlimit_permission(tsk);
+	if (ret)
+		goto err_unlock;
+
+	task_lock(tsk->group_leader);
+	val = tsk->signal->rlim[resource];
+	task_unlock(tsk->group_leader);
+
+	read_unlock(&tasklist_lock);
+
+	return copy_to_user(rlim, &val, sizeof(*rlim)) ? -EFAULT : 0;
+err_unlock:
+	read_unlock(&tasklist_lock);
+	return ret;
+}
+
+
 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
 
 /*
@@ -1237,43 +1291,50 @@ SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
 
 #endif
 
-SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
+/* make sure you are allowed to change @tsk limits before calling this */
+int do_setrlimit(struct task_struct *tsk, unsigned int resource,
+		struct rlimit *new_rlim)
 {
-	struct rlimit new_rlim, *old_rlim;
-	int retval;
+	struct rlimit *old_rlim;
+	int retval = 0;
 
-	if (resource >= RLIM_NLIMITS)
+	if (new_rlim->rlim_cur > new_rlim->rlim_max)
 		return -EINVAL;
-	if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
-		return -EFAULT;
-	if (new_rlim.rlim_cur > new_rlim.rlim_max)
-		return -EINVAL;
-	old_rlim = current->signal->rlim + resource;
-	if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
-	    !capable(CAP_SYS_RESOURCE))
-		return -EPERM;
-	if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open)
+	if (resource == RLIMIT_NOFILE && new_rlim->rlim_max > sysctl_nr_open)
 		return -EPERM;
 
-	retval = security_task_setrlimit(resource, &new_rlim);
-	if (retval)
-		return retval;
+	/* optimization: 'current' doesn't need locking, e.g. setrlimit */
+	if (tsk != current) {
+		/* protect tsk->signal and tsk->sighand from disappearing */
+		read_lock(&tasklist_lock);
+		if (!tsk->sighand) {
+			retval = -ESRCH;
+			goto out;
+		}
+	}
 
-	if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) {
+	if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
 		/*
 		 * The caller is asking for an immediate RLIMIT_CPU
 		 * expiry.  But we use the zero value to mean "it was
 		 * never set".  So let's cheat and make it one second
 		 * instead
 		 */
-		new_rlim.rlim_cur = 1;
+		new_rlim->rlim_cur = 1;
 	}
 
-	task_lock(current->group_leader);
-	*old_rlim = new_rlim;
-	task_unlock(current->group_leader);
-
-	if (resource != RLIMIT_CPU)
+	old_rlim = tsk->signal->rlim + resource;
+	task_lock(tsk->group_leader);
+	if ((new_rlim->rlim_max > old_rlim->rlim_max) &&
+				!capable(CAP_SYS_RESOURCE))
+		retval = -EPERM;
+	if (!retval)
+		retval = security_task_setrlimit(tsk, resource, new_rlim);
+	if (!retval)
+		*old_rlim = *new_rlim;
+	task_unlock(tsk->group_leader);
+
+	if (retval || resource != RLIMIT_CPU)
 		goto out;
 
 	/*
@@ -1282,12 +1343,56 @@ SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
 	 * very long-standing error, and fixing it now risks breakage of
 	 * applications, so we live with it
 	 */
-	if (new_rlim.rlim_cur == RLIM_INFINITY)
+	if (new_rlim->rlim_cur == RLIM_INFINITY)
 		goto out;
 
-	update_rlimit_cpu(new_rlim.rlim_cur);
+	update_rlimit_cpu(tsk, new_rlim->rlim_cur);
 out:
-	return 0;
+	if (tsk != current)
+		read_unlock(&tasklist_lock);
+	return retval;
+}
+
+SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
+{
+	struct rlimit new_rlim;
+
+	if (resource >= RLIM_NLIMITS)
+		return -EINVAL;
+	if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
+		return -EFAULT;
+	return do_setrlimit(current, resource, &new_rlim);
+}
+
+SYSCALL_DEFINE3(setprlimit, pid_t, pid, unsigned int, resource,
+		struct rlimit __user *, rlim)
+{
+	struct task_struct *tsk;
+	struct rlimit new_rlim;
+	int ret;
+
+	if (resource >= RLIM_NLIMITS)
+		return -EINVAL;
+
+	if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
+		return -EFAULT;
+
+	rcu_read_lock();
+	tsk = find_task_by_vpid(pid);
+	if (!tsk) {
+		rcu_read_unlock();
+		return -ESRCH;
+	}
+	get_task_struct(tsk);
+	rcu_read_unlock();
+
+	ret = check_prlimit_permission(tsk);
+	if (!ret)
+		ret = do_setrlimit(tsk, resource, &new_rlim);
+
+	put_task_struct(tsk);
+
+	return ret;
 }
 
 /*
diff --git a/mm/filemap.c b/mm/filemap.c
index 8b4d88f9249e..87dbcb3462be 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1950,7 +1950,7 @@ EXPORT_SYMBOL(iov_iter_single_seg_count);
 inline int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk)
 {
 	struct inode *inode = file->f_mapping->host;
-	unsigned long limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
+	unsigned long limit = rlimit(RLIMIT_FSIZE);
 
         if (unlikely(*pos < 0))
                 return -EINVAL;
diff --git a/mm/mlock.c b/mm/mlock.c
index bd6f0e466f6c..2efb17db69fe 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -25,7 +25,7 @@ int can_do_mlock(void)
 {
 	if (capable(CAP_IPC_LOCK))
 		return 1;
-	if (current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur != 0)
+	if (rlimit(RLIMIT_MEMLOCK) != 0)
 		return 1;
 	return 0;
 }
@@ -490,7 +490,7 @@ SYSCALL_DEFINE2(mlock, unsigned long, start, size_t, len)
 	locked = len >> PAGE_SHIFT;
 	locked += current->mm->locked_vm;
 
-	lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+	lock_limit = rlimit(RLIMIT_MEMLOCK);
 	lock_limit >>= PAGE_SHIFT;
 
 	/* check against resource limits */
@@ -553,7 +553,7 @@ SYSCALL_DEFINE1(mlockall, int, flags)
 
 	down_write(&current->mm->mmap_sem);
 
-	lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+	lock_limit = rlimit(RLIMIT_MEMLOCK);
 	lock_limit >>= PAGE_SHIFT;
 
 	ret = -ENOMEM;
@@ -587,7 +587,7 @@ int user_shm_lock(size_t size, struct user_struct *user)
 	int allowed = 0;
 
 	locked = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+	lock_limit = rlimit(RLIMIT_MEMLOCK);
 	if (lock_limit == RLIM_INFINITY)
 		allowed = 1;
 	lock_limit >>= PAGE_SHIFT;
@@ -621,12 +621,12 @@ int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim,
 
 	down_write(&mm->mmap_sem);
 
-	lim = rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
+	lim = ACCESS_ONCE(rlim[RLIMIT_AS].rlim_cur) >> PAGE_SHIFT;
 	vm   = mm->total_vm + pgsz;
 	if (lim < vm)
 		goto out;
 
-	lim = rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
+	lim = ACCESS_ONCE(rlim[RLIMIT_MEMLOCK].rlim_cur) >> PAGE_SHIFT;
 	vm   = mm->locked_vm + pgsz;
 	if (lim < vm)
 		goto out;
diff --git a/mm/mmap.c b/mm/mmap.c
index 292ddc3cef9c..aee8df8e058d 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -265,7 +265,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 	 * segment grow beyond its set limit the in case where the limit is
 	 * not page aligned -Ram Gupta
 	 */
-	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
+	rlim = rlimit(RLIMIT_DATA);
 	if (rlim < RLIM_INFINITY && (brk - mm->start_brk) +
 			(mm->end_data - mm->start_data) > rlim)
 		goto out;
@@ -989,7 +989,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
 		unsigned long locked, lock_limit;
 		locked = len >> PAGE_SHIFT;
 		locked += mm->locked_vm;
-		lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+		lock_limit = rlimit(RLIMIT_MEMLOCK);
 		lock_limit >>= PAGE_SHIFT;
 		if (locked > lock_limit && !capable(CAP_IPC_LOCK))
 			return -EAGAIN;
@@ -1561,7 +1561,7 @@ static int acct_stack_growth(struct vm_area_struct *vma, unsigned long size, uns
 		return -ENOMEM;
 
 	/* Stack limit test */
-	if (size > rlim[RLIMIT_STACK].rlim_cur)
+	if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur))
 		return -ENOMEM;
 
 	/* mlock limit tests */
@@ -1569,7 +1569,8 @@ static int acct_stack_growth(struct vm_area_struct *vma, unsigned long size, uns
 		unsigned long locked;
 		unsigned long limit;
 		locked = mm->locked_vm + grow;
-		limit = rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
+		limit = ACCESS_ONCE(rlim[RLIMIT_MEMLOCK].rlim_cur);
+		limit >>= PAGE_SHIFT;
 		if (locked > limit && !capable(CAP_IPC_LOCK))
 			return -ENOMEM;
 	}
@@ -2022,7 +2023,7 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
 		unsigned long locked, lock_limit;
 		locked = len >> PAGE_SHIFT;
 		locked += mm->locked_vm;
-		lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+		lock_limit = rlimit(RLIMIT_MEMLOCK);
 		lock_limit >>= PAGE_SHIFT;
 		if (locked > lock_limit && !capable(CAP_IPC_LOCK))
 			return -EAGAIN;
@@ -2236,7 +2237,7 @@ int may_expand_vm(struct mm_struct *mm, unsigned long npages)
 	unsigned long cur = mm->total_vm;	/* pages */
 	unsigned long lim;
 
-	lim = current->signal->rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
+	lim = rlimit(RLIMIT_AS) >> PAGE_SHIFT;
 
 	if (cur + npages > lim)
 		return 0;
diff --git a/mm/mremap.c b/mm/mremap.c
index 97bff2547719..d6740a131998 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -358,7 +358,7 @@ unsigned long do_mremap(unsigned long addr,
 	if (vma->vm_flags & VM_LOCKED) {
 		unsigned long locked, lock_limit;
 		locked = mm->locked_vm << PAGE_SHIFT;
-		lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+		lock_limit = rlimit(RLIMIT_MEMLOCK);
 		locked += new_len - old_len;
 		ret = -EAGAIN;
 		if (locked > lock_limit && !capable(CAP_IPC_LOCK))
diff --git a/security/capability.c b/security/capability.c
index 5c700e1a4fd3..10f23a4c84e5 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -466,7 +466,8 @@ static int cap_task_getioprio(struct task_struct *p)
 	return 0;
 }
 
-static int cap_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
+static int cap_task_setrlimit(struct task_struct *p, unsigned int resource,
+		struct rlimit *new_rlim)
 {
 	return 0;
 }
diff --git a/security/security.c b/security/security.c
index f2d8aa949323..1f163d6e917f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -826,9 +826,10 @@ int security_task_getioprio(struct task_struct *p)
 	return security_ops->task_getioprio(p);
 }
 
-int security_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
+int security_task_setrlimit(struct task_struct *p, unsigned int resource,
+		struct rlimit *new_rlim)
 {
-	return security_ops->task_setrlimit(resource, new_rlim);
+	return security_ops->task_setrlimit(p, resource, new_rlim);
 }
 
 int security_task_setscheduler(struct task_struct *p,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 7a374c2eb043..9688ccc73c00 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2365,7 +2365,8 @@ static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
 			initrlim = init_task.signal->rlim + i;
 			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
 		}
-		update_rlimit_cpu(rlim->rlim_cur);
+		update_rlimit_cpu(current,
+				current->signal->rlim[RLIMIT_CPU].rlim_cur);
 	}
 }
 
@@ -3398,16 +3399,17 @@ static int selinux_task_getioprio(struct task_struct *p)
 	return current_has_perm(p, PROCESS__GETSCHED);
 }
 
-static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
+static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
+		struct rlimit *new_rlim)
 {
-	struct rlimit *old_rlim = current->signal->rlim + resource;
+	struct rlimit *old_rlim = p->signal->rlim + resource;
 
 	/* Control the ability to change the hard limit (whether
 	   lowering or raising it), so that the hard limit can
 	   later be used as a safe reset point for the soft limit
 	   upon context transitions.  See selinux_bprm_committing_creds. */
 	if (old_rlim->rlim_max != new_rlim->rlim_max)
-		return current_has_perm(current, PROCESS__SETRLIMIT);
+		return current_has_perm(p, PROCESS__SETRLIMIT);
 
 	return 0;
 }