Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "15 patches.

  Subsystems affected by this patch series: ipc, hexagon, mm (swap,
  slab-generic, kmemleak, hugetlb, kasan, damon, and highmem), and proc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  proc/vmcore: fix clearing user buffer by properly using clear_user()
  kmap_local: don't assume kmap PTEs are linear arrays in memory
  mm/damon/dbgfs: fix missed use of damon_dbgfs_lock
  mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation
  kasan: test: silence intentional read overflow warnings
  hugetlb, userfaultfd: fix reservation restore on userfaultfd error
  hugetlb: fix hugetlb cgroup refcounting during mremap
  mm: kmemleak: slob: respect SLAB_NOLEAKTRACE flag
  hexagon: ignore vmlinux.lds
  hexagon: clean up timer-regs.h
  hexagon: export raw I/O routines for modules
  mm: emit the "free" trace report before freeing memory in kmem_cache_free()
  shm: extend forced shm destroy to support objects from several IPC nses
  ipc: WARN if trying to remove ipc object which is absent
  mm/swap.c:put_pages_list(): reinitialise the page list

arch/arm/Kconfig

@@ -1463,6 +1463,7 @@ config HIGHMEM
 	bool "High Memory Support"
 	depends on MMU
 	select KMAP_LOCAL
+	select KMAP_LOCAL_NON_LINEAR_PTE_ARRAY
 	help
 	  The address space of ARM processors is only 4 Gigabytes large
 	  and it has to accommodate user address space, kernel address

arch/hexagon/include/asm/timex.h

@@ -7,11 +7,10 @@
 #define _ASM_TIMEX_H
 
 #include <asm-generic/timex.h>
-#include <asm/timer-regs.h>
 #include <asm/hexagon_vm.h>
 
 /* Using TCX0 as our clock.  CLOCK_TICK_RATE scheduled to be removed. */
-#define CLOCK_TICK_RATE              TCX0_CLK_RATE
+#define CLOCK_TICK_RATE              19200
 
 #define ARCH_HAS_READ_CURRENT_TIMER
 

arch/hexagon/kernel/.gitignore

@@ -0,0 +1 @@
+vmlinux.lds

arch/hexagon/kernel/time.c

@@ -17,9 +17,10 @@
 #include <linux/of_irq.h>
 #include <linux/module.h>
 
-#include <asm/timer-regs.h>
 #include <asm/hexagon_vm.h>
 
+#define TIMER_ENABLE		BIT(0)
+
 /*
  * For the clocksource we need:
  *	pcycle frequency (600MHz)
@@ -33,6 +34,13 @@ cycles_t	pcycle_freq_mhz;
 cycles_t	thread_freq_mhz;
 cycles_t	sleep_clk_freq;
 
+/*
+ * 8x50 HDD Specs 5-8.  Simulator co-sim not fixed until
+ * release 1.1, and then it's "adjustable" and probably not defaulted.
+ */
+#define RTOS_TIMER_INT		3
+#define RTOS_TIMER_REGS_ADDR	0xAB000000UL
+
 static struct resource rtos_timer_resources[] = {
 	{
 		.start	= RTOS_TIMER_REGS_ADDR,
@@ -80,7 +88,7 @@ static int set_next_event(unsigned long delta, struct clock_event_device *evt)
 	iowrite32(0, &rtos_timer->clear);
 
 	iowrite32(delta, &rtos_timer->match);
-	iowrite32(1 << TIMER_ENABLE, &rtos_timer->enable);
+	iowrite32(TIMER_ENABLE, &rtos_timer->enable);
 	return 0;
 }
 

arch/hexagon/lib/io.c

@@ -27,6 +27,7 @@ void __raw_readsw(const void __iomem *addr, void *data, int len)
 		*dst++ = *src;
 
 }
+EXPORT_SYMBOL(__raw_readsw);
 
 /*
  * __raw_writesw - read words a short at a time
@@ -47,6 +48,7 @@ void __raw_writesw(void __iomem *addr, const void *data, int len)
 
 
 }
+EXPORT_SYMBOL(__raw_writesw);
 
 /*  Pretty sure len is pre-adjusted for the length of the access already */
 void __raw_readsl(const void __iomem *addr, void *data, int len)
@@ -62,6 +64,7 @@ void __raw_readsl(const void __iomem *addr, void *data, int len)
 
 
 }
+EXPORT_SYMBOL(__raw_readsl);
 
 void __raw_writesl(void __iomem *addr, const void *data, int len)
 {
@@ -76,3 +79,4 @@ void __raw_writesl(void __iomem *addr, const void *data, int len)
 
 
 }
+EXPORT_SYMBOL(__raw_writesl);

fs/proc/vmcore.c

@@ -154,9 +154,13 @@ ssize_t read_from_oldmem(char *buf, size_t count,
 			nr_bytes = count;
 
 		/* If pfn is not ram, return zeros for sparse dump files */
-		if (!pfn_is_ram(pfn))
-			memset(buf, 0, nr_bytes);
-		else {
+		if (!pfn_is_ram(pfn)) {
+			tmp = 0;
+			if (!userbuf)
+				memset(buf, 0, nr_bytes);
+			else if (clear_user(buf, nr_bytes))
+				tmp = -EFAULT;
+		} else {
 			if (encrypted)
 				tmp = copy_oldmem_page_encrypted(pfn, buf,
 								 nr_bytes,
@@ -165,12 +169,12 @@ ssize_t read_from_oldmem(char *buf, size_t count,
 			else
 				tmp = copy_oldmem_page(pfn, buf, nr_bytes,
 						       offset, userbuf);
-
-			if (tmp < 0) {
-				up_read(&vmcore_cb_rwsem);
-				return tmp;
-			}
 		}
+		if (tmp < 0) {
+			up_read(&vmcore_cb_rwsem);
+			return tmp;
+		}
+
 		*ppos += nr_bytes;
 		count -= nr_bytes;
 		buf += nr_bytes;

include/linux/hugetlb_cgroup.h

@@ -128,6 +128,13 @@ static inline void resv_map_dup_hugetlb_cgroup_uncharge_info(
 		css_get(resv_map->css);
 }
 
+static inline void resv_map_put_hugetlb_cgroup_uncharge_info(
+						struct resv_map *resv_map)
+{
+	if (resv_map->css)
+		css_put(resv_map->css);
+}
+
 extern int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
 					struct hugetlb_cgroup **ptr);
 extern int hugetlb_cgroup_charge_cgroup_rsvd(int idx, unsigned long nr_pages,
@@ -211,6 +218,11 @@ static inline void resv_map_dup_hugetlb_cgroup_uncharge_info(
 {
 }
 
+static inline void resv_map_put_hugetlb_cgroup_uncharge_info(
+						struct resv_map *resv_map)
+{
+}
+
 static inline int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
 					       struct hugetlb_cgroup **ptr)
 {

include/linux/ipc_namespace.h

@@ -131,6 +131,16 @@ static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 	return ns;
 }
 
+static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
+{
+	if (ns) {
+		if (refcount_inc_not_zero(&ns->ns.count))
+			return ns;
+	}
+
+	return NULL;
+}
+
 extern void put_ipc_ns(struct ipc_namespace *ns);
 #else
 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
@@ -147,6 +157,11 @@ static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 	return ns;
 }
 
+static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
+{
+	return ns;
+}
+
 static inline void put_ipc_ns(struct ipc_namespace *ns)
 {
 }

include/linux/sched/task.h

@@ -158,7 +158,7 @@ static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
  * pins the final release of task.io_context.  Also protects ->cpuset and
- * ->cgroup.subsys[]. And ->vfork_done.
+ * ->cgroup.subsys[]. And ->vfork_done. And ->sysvshm.shm_clist.
  *
  * Nests both inside and outside of read_lock(&tasklist_lock).
  * It must not be nested with write_lock_irq(&tasklist_lock),