Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - almost all of the rest of MM

 - kasan updates

 - lots of procfs work

 - misc things

 - lib/ updates

 - checkpatch

 - rapidio

 - ipc/shm updates

 - the start of willy's XArray conversion

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (140 commits)
  page cache: use xa_lock
  xarray: add the xa_lock to the radix_tree_root
  fscache: use appropriate radix tree accessors
  export __set_page_dirty
  unicore32: turn flush_dcache_mmap_lock into a no-op
  arm64: turn flush_dcache_mmap_lock into a no-op
  mac80211_hwsim: use DEFINE_IDA
  radix tree: use GFP_ZONEMASK bits of gfp_t for flags
  linux/const.h: refactor _BITUL and _BITULL a bit
  linux/const.h: move UL() macro to include/linux/const.h
  linux/const.h: prefix include guard of uapi/linux/const.h with _UAPI
  xen, mm: allow deferred page initialization for xen pv domains
  elf: enforce MAP_FIXED on overlaying elf segments
  fs, elf: drop MAP_FIXED usage from elf_map
  mm: introduce MAP_FIXED_NOREPLACE
  MAINTAINERS: update bouncing aacraid@adaptec.com addresses
  fs/dcache.c: add cond_resched() in shrink_dentry_list()
  include/linux/kfifo.h: fix comment
  ipc/shm.c: shm_split(): remove unneeded test for NULL shm_file_data.vm_ops
  kernel/sysctl.c: add kdoc comments to do_proc_do{u}intvec_minmax_conv_param
  ...

1 files changed, 21 insertions, 6 deletions

diff --git a/fs/exec.c b/fs/exec.c
index a919a827d181..183059c427b9 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -257,7 +257,7 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
 		 *    to work from.
 		 */
 		limit = _STK_LIM / 4 * 3;
-		limit = min(limit, rlimit(RLIMIT_STACK) / 4);
+		limit = min(limit, bprm->rlim_stack.rlim_cur / 4);
 		if (size > limit)
 			goto fail;
 	}
@@ -411,6 +411,11 @@ static int bprm_mm_init(struct linux_binprm *bprm)
 	if (!mm)
 		goto err;
 
+	/* Save current stack limit for all calculations made during exec. */
+	task_lock(current->group_leader);
+	bprm->rlim_stack = current->signal->rlim[RLIMIT_STACK];
+	task_unlock(current->group_leader);
+
 	err = __bprm_mm_init(bprm);
 	if (err)
 		goto err;
@@ -697,7 +702,7 @@ int setup_arg_pages(struct linux_binprm *bprm,
 
 #ifdef CONFIG_STACK_GROWSUP
 	/* Limit stack size */
-	stack_base = rlimit_max(RLIMIT_STACK);
+	stack_base = bprm->rlim_stack.rlim_max;
 	if (stack_base > STACK_SIZE_MAX)
 		stack_base = STACK_SIZE_MAX;
 
@@ -770,7 +775,7 @@ int setup_arg_pages(struct linux_binprm *bprm,
 	 * Align this down to a page boundary as expand_stack
 	 * will align it up.
 	 */
-	rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK;
+	rlim_stack = bprm->rlim_stack.rlim_cur & PAGE_MASK;
 #ifdef CONFIG_STACK_GROWSUP
 	if (stack_size + stack_expand > rlim_stack)
 		stack_base = vma->vm_start + rlim_stack;
@@ -1341,11 +1346,11 @@ void setup_new_exec(struct linux_binprm * bprm)
 		 * RLIMIT_STACK, but after the point of no return to avoid
 		 * needing to clean up the change on failure.
 		 */
-		if (current->signal->rlim[RLIMIT_STACK].rlim_cur > _STK_LIM)
-			current->signal->rlim[RLIMIT_STACK].rlim_cur = _STK_LIM;
+		if (bprm->rlim_stack.rlim_cur > _STK_LIM)
+			bprm->rlim_stack.rlim_cur = _STK_LIM;
 	}
 
-	arch_pick_mmap_layout(current->mm);
+	arch_pick_mmap_layout(current->mm, &bprm->rlim_stack);
 
 	current->sas_ss_sp = current->sas_ss_size = 0;
 
@@ -1378,6 +1383,16 @@ void setup_new_exec(struct linux_binprm * bprm)
 }
 EXPORT_SYMBOL(setup_new_exec);
 
+/* Runs immediately before start_thread() takes over. */
+void finalize_exec(struct linux_binprm *bprm)
+{
+	/* Store any stack rlimit changes before starting thread. */
+	task_lock(current->group_leader);
+	current->signal->rlim[RLIMIT_STACK] = bprm->rlim_stack;
+	task_unlock(current->group_leader);
+}
+EXPORT_SYMBOL(finalize_exec);
+
 /*
  * Prepare credentials and lock ->cred_guard_mutex.
  * install_exec_creds() commits the new creds and drops the lock.