Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "17 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  arch: define weak abort()
  mm, oom_reaper: fix memory corruption
  kernel: make groups_sort calling a responsibility group_info allocators
  mm/frame_vector.c: release a semaphore in 'get_vaddr_frames()'
  tools/slabinfo-gnuplot: force to use bash shell
  kcov: fix comparison callback signature
  mm/slab.c: do not hash pointers when debugging slab
  mm/page_alloc.c: avoid excessive IRQ disabled times in free_unref_page_list()
  mm/memory.c: mark wp_huge_pmd() inline to prevent build failure
  scripts/faddr2line: fix CROSS_COMPILE unset error
  Documentation/vm/zswap.txt: update with same-value filled page feature
  exec: avoid gcc-8 warning for get_task_comm
  autofs: fix careless error in recent commit
  string.h: workaround for increased stack usage
  mm/kmemleak.c: make cond_resched() rate-limiting more efficient
  lib/rbtree,drm/mm: add rbtree_replace_node_cached()
  include/linux/idr.h: add #include <linux/bug.h>

Documentation/vm/zswap.txt

@@ -98,5 +98,25 @@ request is made for a page in an old zpool, it is uncompressed using its
 original compressor.  Once all pages are removed from an old zpool, the zpool
 and its compressor are freed.
 
+Some of the pages in zswap are same-value filled pages (i.e. contents of the
+page have same value or repetitive pattern). These pages include zero-filled
+pages and they are handled differently. During store operation, a page is
+checked if it is a same-value filled page before compressing it. If true, the
+compressed length of the page is set to zero and the pattern or same-filled
+value is stored.
+
+Same-value filled pages identification feature is enabled by default and can be
+disabled at boot time by setting the "same_filled_pages_enabled" attribute to 0,
+e.g. zswap.same_filled_pages_enabled=0. It can also be enabled and disabled at
+runtime using the sysfs "same_filled_pages_enabled" attribute, e.g.
+
+echo 1 > /sys/module/zswap/parameters/same_filled_pages_enabled
+
+When zswap same-filled page identification is disabled at runtime, it will stop
+checking for the same-value filled pages during store operation. However, the
+existing pages which are marked as same-value filled pages remain stored
+unchanged in zswap until they are either loaded or invalidated.
+
 A debugfs interface is provided for various statistic about pool size, number
-of pages stored, and various counters for the reasons pages are rejected.
+of pages stored, same-value filled pages and various counters for the reasons
+pages are rejected.

arch/s390/kernel/compat_linux.c

@@ -263,6 +263,7 @@ COMPAT_SYSCALL_DEFINE2(s390_setgroups16, int, gidsetsize, u16 __user *, grouplis
 		return retval;
 	}
 
+	groups_sort(group_info);
 	retval = set_current_groups(group_info);
 	put_group_info(group_info);
 

drivers/gpu/drm/drm_mm.c

@@ -575,21 +575,23 @@ EXPORT_SYMBOL(drm_mm_remove_node);
  */
 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
 {
+	struct drm_mm *mm = old->mm;
+
 	DRM_MM_BUG_ON(!old->allocated);
 
 	*new = *old;
 
 	list_replace(&old->node_list, &new->node_list);
-	rb_replace_node(&old->rb, &new->rb, &old->mm->interval_tree.rb_root);
+	rb_replace_node_cached(&old->rb, &new->rb, &mm->interval_tree);
 
 	if (drm_mm_hole_follows(old)) {
 		list_replace(&old->hole_stack, &new->hole_stack);
 		rb_replace_node(&old->rb_hole_size,
 				&new->rb_hole_size,
-				&old->mm->holes_size);
+				&mm->holes_size);
 		rb_replace_node(&old->rb_hole_addr,
 				&new->rb_hole_addr,
-				&old->mm->holes_addr);
+				&mm->holes_addr);
 	}
 
 	old->allocated = false;

fs/autofs4/waitq.c

@@ -170,7 +170,6 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
 
 	mutex_unlock(&sbi->wq_mutex);
 
-	if (autofs4_write(sbi, pipe, &pkt, pktsz))
 	switch (ret = autofs4_write(sbi, pipe, &pkt, pktsz)) {
 	case 0:
 		break;

fs/exec.c

@@ -1216,15 +1216,14 @@ static int de_thread(struct task_struct *tsk)
 	return -EAGAIN;
 }
 
-char *get_task_comm(char *buf, struct task_struct *tsk)
+char *__get_task_comm(char *buf, size_t buf_size, struct task_struct *tsk)
 {
-	/* buf must be at least sizeof(tsk->comm) in size */
 	task_lock(tsk);
-	strncpy(buf, tsk->comm, sizeof(tsk->comm));
+	strncpy(buf, tsk->comm, buf_size);
 	task_unlock(tsk);
 	return buf;
 }
-EXPORT_SYMBOL_GPL(get_task_comm);
+EXPORT_SYMBOL_GPL(__get_task_comm);
 
 /*
  * These functions flushes out all traces of the currently running executable

fs/nfsd/auth.c

@@ -60,6 +60,9 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
 				gi->gid[i] = exp->ex_anon_gid;
 			else
 				gi->gid[i] = rqgi->gid[i];
+
+			/* Each thread allocates its own gi, no race */
+			groups_sort(gi);
 		}
 	} else {
 		gi = get_group_info(rqgi);

include/linux/cred.h

@@ -83,6 +83,7 @@ extern int set_current_groups(struct group_info *);
 extern void set_groups(struct cred *, struct group_info *);
 extern int groups_search(const struct group_info *, kgid_t);
 extern bool may_setgroups(void);
+extern void groups_sort(struct group_info *);
 
 /*
  * The security context of a task

include/linux/idr.h

@@ -15,6 +15,7 @@
 #include <linux/radix-tree.h>
 #include <linux/gfp.h>
 #include <linux/percpu.h>
+#include <linux/bug.h>
 
 struct idr {
 	struct radix_tree_root	idr_rt;

include/linux/oom.h

@@ -66,6 +66,15 @@ static inline bool tsk_is_oom_victim(struct task_struct * tsk)
 	return tsk->signal->oom_mm;
 }
 
+/*
+ * Use this helper if tsk->mm != mm and the victim mm needs a special
+ * handling. This is guaranteed to stay true after once set.
+ */
+static inline bool mm_is_oom_victim(struct mm_struct *mm)
+{
+	return test_bit(MMF_OOM_VICTIM, &mm->flags);
+}
+
 /*
  * Checks whether a page fault on the given mm is still reliable.
  * This is no longer true if the oom reaper started to reap the

include/linux/rbtree.h

@@ -99,6 +99,8 @@ extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
 			    struct rb_root *root);
 extern void rb_replace_node_rcu(struct rb_node *victim, struct rb_node *new,
 				struct rb_root *root);
+extern void rb_replace_node_cached(struct rb_node *victim, struct rb_node *new,
+				   struct rb_root_cached *root);
 
 static inline void rb_link_node(struct rb_node *node, struct rb_node *parent,
 				struct rb_node **rb_link)

include/linux/sched.h

@@ -1503,7 +1503,11 @@ static inline void set_task_comm(struct task_struct *tsk, const char *from)
 	__set_task_comm(tsk, from, false);
 }
 
-extern char *get_task_comm(char *to, struct task_struct *tsk);
+extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
+#define get_task_comm(buf, tsk) ({			\
+	BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);	\
+	__get_task_comm(buf, sizeof(buf), tsk);		\
+})
 
 #ifdef CONFIG_SMP
 void scheduler_ipi(void);

include/linux/sched/coredump.h

@@ -70,6 +70,7 @@ static inline int get_dumpable(struct mm_struct *mm)
 #define MMF_UNSTABLE		22	/* mm is unstable for copy_from_user */
 #define MMF_HUGE_ZERO_PAGE	23      /* mm has ever used the global huge zero page */
 #define MMF_DISABLE_THP		24	/* disable THP for all VMAs */
+#define MMF_OOM_VICTIM		25	/* mm is the oom victim */
 #define MMF_DISABLE_THP_MASK	(1 << MMF_DISABLE_THP)
 
 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\

include/linux/string.h

@@ -259,7 +259,10 @@ __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
 {
 	__kernel_size_t ret;
 	size_t p_size = __builtin_object_size(p, 0);
-	if (p_size == (size_t)-1)
+
+	/* Work around gcc excess stack consumption issue */
+	if (p_size == (size_t)-1 ||
+	    (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
 		return __builtin_strlen(p);
 	ret = strnlen(p, p_size);
 	if (p_size <= ret)

kernel/exit.c

@@ -1755,3 +1755,11 @@ COMPAT_SYSCALL_DEFINE5(waitid,
 	return -EFAULT;
 }
 #endif
+
+__weak void abort(void)
+{
+	BUG();
+
+	/* if that doesn't kill us, halt */
+	panic("Oops failed to kill thread");
+}

kernel/groups.c

@@ -86,11 +86,12 @@ static int gid_cmp(const void *_a, const void *_b)
 	return gid_gt(a, b) - gid_lt(a, b);
 }
 
-static void groups_sort(struct group_info *group_info)
+void groups_sort(struct group_info *group_info)
 {
 	sort(group_info->gid, group_info->ngroups, sizeof(*group_info->gid),
 	     gid_cmp, NULL);
 }
+EXPORT_SYMBOL(groups_sort);
 
 /* a simple bsearch */
 int groups_search(const struct group_info *group_info, kgid_t grp)
@@ -122,7 +123,6 @@ int groups_search(const struct group_info *group_info, kgid_t grp)
 void set_groups(struct cred *new, struct group_info *group_info)
 {
 	put_group_info(new->group_info);
-	groups_sort(group_info);
 	get_group_info(group_info);
 	new->group_info = group_info;
 }
@@ -206,6 +206,7 @@ SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist)
 		return retval;
 	}
 
+	groups_sort(group_info);
 	retval = set_current_groups(group_info);
 	put_group_info(group_info);
 

kernel/kcov.c

@@ -157,7 +157,7 @@ void notrace __sanitizer_cov_trace_cmp2(u16 arg1, u16 arg2)
 }
 EXPORT_SYMBOL(__sanitizer_cov_trace_cmp2);
 
-void notrace __sanitizer_cov_trace_cmp4(u16 arg1, u16 arg2)
+void notrace __sanitizer_cov_trace_cmp4(u32 arg1, u32 arg2)
 {
 	write_comp_data(KCOV_CMP_SIZE(2), arg1, arg2, _RET_IP_);
 }
@@ -183,7 +183,7 @@ void notrace __sanitizer_cov_trace_const_cmp2(u16 arg1, u16 arg2)
 }
 EXPORT_SYMBOL(__sanitizer_cov_trace_const_cmp2);
 
-void notrace __sanitizer_cov_trace_const_cmp4(u16 arg1, u16 arg2)
+void notrace __sanitizer_cov_trace_const_cmp4(u32 arg1, u32 arg2)
 {
 	write_comp_data(KCOV_CMP_SIZE(2) | KCOV_CMP_CONST, arg1, arg2,
 			_RET_IP_);

kernel/uid16.c

@@ -192,6 +192,7 @@ SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
 		return retval;
 	}
 
+	groups_sort(group_info);
 	retval = set_current_groups(group_info);
 	put_group_info(group_info);
 

lib/rbtree.c

@@ -603,6 +603,16 @@ void rb_replace_node(struct rb_node *victim, struct rb_node *new,
 }
 EXPORT_SYMBOL(rb_replace_node);
 
+void rb_replace_node_cached(struct rb_node *victim, struct rb_node *new,
+			    struct rb_root_cached *root)
+{
+	rb_replace_node(victim, new, &root->rb_root);
+
+	if (root->rb_leftmost == victim)
+		root->rb_leftmost = new;
+}
+EXPORT_SYMBOL(rb_replace_node_cached);
+
 void rb_replace_node_rcu(struct rb_node *victim, struct rb_node *new,
 			 struct rb_root *root)
 {

mm/frame_vector.c

@@ -62,8 +62,10 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
 	 * get_user_pages_longterm() and disallow it for filesystem-dax
 	 * mappings.
 	 */
-	if (vma_is_fsdax(vma))
-		return -EOPNOTSUPP;
+	if (vma_is_fsdax(vma)) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
 
 	if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
 		vec->got_ref = true;

mm/kmemleak.c

@@ -1523,7 +1523,7 @@ static void kmemleak_scan(void)
 			if (page_count(page) == 0)
 				continue;
 			scan_block(page, page + 1, NULL);
-			if (!(pfn % (MAX_SCAN_SIZE / sizeof(*page))))
+			if (!(pfn & 63))
 				cond_resched();
 		}
 	}

mm/memory.c

@@ -3831,7 +3831,8 @@ static inline int create_huge_pmd(struct vm_fault *vmf)
 	return VM_FAULT_FALLBACK;
 }
 
-static int wp_huge_pmd(struct vm_fault *vmf, pmd_t orig_pmd)
+/* `inline' is required to avoid gcc 4.1.2 build error */
+static inline int wp_huge_pmd(struct vm_fault *vmf, pmd_t orig_pmd)
 {
 	if (vma_is_anonymous(vmf->vma))
 		return do_huge_pmd_wp_page(vmf, orig_pmd);

mm/mmap.c

@@ -3019,20 +3019,20 @@ void exit_mmap(struct mm_struct *mm)
 	/* Use -1 here to ensure all VMAs in the mm are unmapped */
 	unmap_vmas(&tlb, vma, 0, -1);
 
-	set_bit(MMF_OOM_SKIP, &mm->flags);
-	if (unlikely(tsk_is_oom_victim(current))) {
+	if (unlikely(mm_is_oom_victim(mm))) {
 		/*
 		 * Wait for oom_reap_task() to stop working on this
 		 * mm. Because MMF_OOM_SKIP is already set before
 		 * calling down_read(), oom_reap_task() will not run
 		 * on this "mm" post up_write().
 		 *
-		 * tsk_is_oom_victim() cannot be set from under us
-		 * either because current->mm is already set to NULL
+		 * mm_is_oom_victim() cannot be set from under us
+		 * either because victim->mm is already set to NULL
 		 * under task_lock before calling mmput and oom_mm is
-		 * set not NULL by the OOM killer only if current->mm
+		 * set not NULL by the OOM killer only if victim->mm
 		 * is found not NULL while holding the task_lock.
 		 */
+		set_bit(MMF_OOM_SKIP, &mm->flags);
 		down_write(&mm->mmap_sem);
 		up_write(&mm->mmap_sem);
 	}

mm/oom_kill.c

@@ -683,8 +683,10 @@ static void mark_oom_victim(struct task_struct *tsk)
 		return;
 
 	/* oom_mm is bound to the signal struct life time. */
-	if (!cmpxchg(&tsk->signal->oom_mm, NULL, mm))
+	if (!cmpxchg(&tsk->signal->oom_mm, NULL, mm)) {
 		mmgrab(tsk->signal->oom_mm);
+		set_bit(MMF_OOM_VICTIM, &mm->flags);
+	}
 
 	/*
 	 * Make sure that the task is woken up from uninterruptible sleep

mm/page_alloc.c

@@ -2684,6 +2684,7 @@ void free_unref_page_list(struct list_head *list)
 {
 	struct page *page, *next;
 	unsigned long flags, pfn;
+	int batch_count = 0;
 
 	/* Prepare pages for freeing */
 	list_for_each_entry_safe(page, next, list, lru) {
@@ -2700,6 +2701,16 @@ void free_unref_page_list(struct list_head *list)
 		set_page_private(page, 0);
 		trace_mm_page_free_batched(page);
 		free_unref_page_commit(page, pfn);
+
+		/*
+		 * Guard against excessive IRQ disabled times when we get
+		 * a large list of pages to free.
+		 */
+		if (++batch_count == SWAP_CLUSTER_MAX) {
+			local_irq_restore(flags);
+			batch_count = 0;
+			local_irq_save(flags);
+		}
 	}
 	local_irq_restore(flags);
 }