Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - most of the rest of MM

 - KASAN updates

 - lib/ updates

 - checkpatch updates

 - some binfmt_elf changes

 - various misc bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (115 commits)
  kernel/exit.c: avoid undefined behaviour when calling wait4()
  kernel/signal.c: avoid undefined behaviour in kill_something_info
  binfmt_elf: safely increment argv pointers
  s390: reduce ELF_ET_DYN_BASE
  powerpc: move ELF_ET_DYN_BASE to 4GB / 4MB
  arm64: move ELF_ET_DYN_BASE to 4GB / 4MB
  arm: move ELF_ET_DYN_BASE to 4MB
  binfmt_elf: use ELF_ET_DYN_BASE only for PIE
  fs, epoll: short circuit fetching events if thread has been killed
  checkpatch: improve multi-line alignment test
  checkpatch: improve macro reuse test
  checkpatch: change format of --color argument to --color[=WHEN]
  checkpatch: silence perl 5.26.0 unescaped left brace warnings
  checkpatch: improve tests for multiple line function definitions
  checkpatch: remove false warning for commit reference
  checkpatch: fix stepping through statements with $stat and ctx_statement_block
  checkpatch: [HLP]LIST_HEAD is also declaration
  checkpatch: warn when a MAINTAINERS entry isn't [A-Z]:\t
  checkpatch: improve the unnecessary OOM message test
  lib/bsearch.c: micro-optimize pivot position calculation
  ...

8 files changed, 28 insertions, 38 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 608c9775a37b..c5548faa9f37 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1639,6 +1639,10 @@ long kernel_wait4(pid_t upid, int __user *stat_addr, int options,
 			__WNOTHREAD|__WCLONE|__WALL))
 		return -EINVAL;
 
+	/* -INT_MIN is not defined */
+	if (upid == INT_MIN)
+		return -ESRCH;
+
 	if (upid == -1)
 		type = PIDTYPE_MAX;
 	else if (upid < 0) {
diff --git a/kernel/extable.c b/kernel/extable.c
index 223df4a328a4..38c2412401a1 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -55,7 +55,8 @@ const struct exception_table_entry *search_exception_tables(unsigned long addr)
 {
 	const struct exception_table_entry *e;
 
-	e = search_extable(__start___ex_table, __stop___ex_table-1, addr);
+	e = search_extable(__start___ex_table,
+			   __stop___ex_table - __start___ex_table, addr);
 	if (!e)
 		e = search_module_extables(addr);
 	return e;
diff --git a/kernel/groups.c b/kernel/groups.c
index d09727692a2a..434f6665f187 100644
--- a/kernel/groups.c
+++ b/kernel/groups.c
@@ -5,6 +5,7 @@
 #include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/security.h>
+#include <linux/sort.h>
 #include <linux/syscalls.h>
 #include <linux/user_namespace.h>
 #include <linux/vmalloc.h>
@@ -76,32 +77,18 @@ static int groups_from_user(struct group_info *group_info,
 	return 0;
 }
 
-/* a simple Shell sort */
+static int gid_cmp(const void *_a, const void *_b)
+{
+	kgid_t a = *(kgid_t *)_a;
+	kgid_t b = *(kgid_t *)_b;
+
+	return gid_gt(a, b) - gid_lt(a, b);
+}
+
 static void groups_sort(struct group_info *group_info)
 {
-	int base, max, stride;
-	int gidsetsize = group_info->ngroups;
-
-	for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
-		; /* nothing */
-	stride /= 3;
-
-	while (stride) {
-		max = gidsetsize - stride;
-		for (base = 0; base < max; base++) {
-			int left = base;
-			int right = left + stride;
-			kgid_t tmp = group_info->gid[right];
-
-			while (left >= 0 && gid_gt(group_info->gid[left], tmp)) {
-				group_info->gid[right] = group_info->gid[left];
-				right = left;
-				left -= stride;
-			}
-			group_info->gid[right] = tmp;
-		}
-		stride /= 3;
-	}
+	sort(group_info->gid, group_info->ngroups, sizeof(*group_info->gid),
+	     gid_cmp, NULL);
 }
 
 /* a simple bsearch */
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 6a3b249a2ae1..127e7cfafa55 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -28,12 +28,6 @@
 
 #include <asm/sections.h>
 
-#ifdef CONFIG_KALLSYMS_ALL
-#define all_var 1
-#else
-#define all_var 0
-#endif
-
 /*
  * These will be re-linked against their real values
  * during the second link stage.
@@ -82,7 +76,7 @@ static inline int is_kernel(unsigned long addr)
 
 static int is_ksym_addr(unsigned long addr)
 {
-	if (all_var)
+	if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
 		return is_kernel(addr);
 
 	return is_kernel_text(addr) || is_kernel_inittext(addr);
@@ -280,7 +274,7 @@ static unsigned long get_symbol_pos(unsigned long addr,
 	if (!symbol_end) {
 		if (is_kernel_inittext(addr))
 			symbol_end = (unsigned long)_einittext;
-		else if (all_var)
+		else if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
 			symbol_end = (unsigned long)_end;
 		else
 			symbol_end = (unsigned long)_etext;
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 23cd70651238..df1a9aa602a0 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -234,7 +234,7 @@ static struct attribute * kernel_attrs[] = {
 	NULL
 };
 
-static struct attribute_group kernel_attr_group = {
+static const struct attribute_group kernel_attr_group = {
 	.attrs = kernel_attrs,
 };
 
diff --git a/kernel/module.c b/kernel/module.c
index b3dbdde82e80..b0f92a365140 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4196,7 +4196,7 @@ const struct exception_table_entry *search_module_extables(unsigned long addr)
 		goto out;
 
 	e = search_extable(mod->extable,
-			   mod->extable + mod->num_exentries - 1,
+			   mod->num_exentries,
 			   addr);
 out:
 	preempt_enable();
diff --git a/kernel/signal.c b/kernel/signal.c
index 48a59eefd8ad..caed9133ae52 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1402,6 +1402,10 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
 		return ret;
 	}
 
+	/* -INT_MIN is undefined.  Exclude this case to avoid a UBSAN warning */
+	if (pid == INT_MIN)
+		return -ESRCH;
+
 	read_lock(&tasklist_lock);
 	if (pid != -1) {
 		ret = __kill_pgrp_info(sig, info,
diff --git a/kernel/sys.c b/kernel/sys.c
index 47d901586b4e..73fc0af147d0 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -2360,7 +2360,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 	case PR_GET_THP_DISABLE:
 		if (arg2 || arg3 || arg4 || arg5)
 			return -EINVAL;
-		error = !!(me->mm->def_flags & VM_NOHUGEPAGE);
+		error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
 		break;
 	case PR_SET_THP_DISABLE:
 		if (arg3 || arg4 || arg5)
@@ -2368,9 +2368,9 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 		if (down_write_killable(&me->mm->mmap_sem))
 			return -EINTR;
 		if (arg2)
-			me->mm->def_flags |= VM_NOHUGEPAGE;
+			set_bit(MMF_DISABLE_THP, &me->mm->flags);
 		else
-			me->mm->def_flags &= ~VM_NOHUGEPAGE;
+			clear_bit(MMF_DISABLE_THP, &me->mm->flags);
 		up_write(&me->mm->mmap_sem);
 		break;
 	case PR_MPX_ENABLE_MANAGEMENT: