Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "Various misc subsystems, before getting into the post-linux-next
  material.

  41 patches.

  Subsystems affected by this patch series: procfs, misc, core-kernel,
  lib, checkpatch, init, pipe, minix, fat, cgroups, kexec, kdump,
  taskstats, panic, kcov, resource, and ubsan"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (41 commits)
  Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang"
  kernel/resource: fix kfree() of bootmem memory again
  kcov: properly handle subsequent mmap calls
  kcov: split ioctl handling into locked and unlocked parts
  panic: move panic_print before kmsg dumpers
  panic: add option to dump all CPUs backtraces in panic_print
  docs: sysctl/kernel: add missing bit to panic_print
  taskstats: remove unneeded dead assignment
  kasan: no need to unset panic_on_warn in end_report()
  ubsan: no need to unset panic_on_warn in ubsan_epilogue()
  panic: unset panic_on_warn inside panic()
  docs: kdump: add scp example to write out the dump file
  docs: kdump: update description about sysfs file system support
  arm64: mm: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
  x86/setup: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
  riscv: mm: init: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
  kexec: make crashk_res, crashk_low_res and crash_notes symbols always visible
  cgroup: use irqsave in cgroup_rstat_flush_locked().
  fat: use pointer to simple type in put_user()
  minix: fix bug when opening a file with O_DIRECT
  ...

1 files changed, 8 insertions, 33 deletions

diff --git a/kernel/resource.c b/kernel/resource.c
index 9c08d6e9eef2..34eaee179689 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -56,14 +56,6 @@ struct resource_constraint {
 
 static DEFINE_RWLOCK(resource_lock);
 
-/*
- * For memory hotplug, there is no way to free resource entries allocated
- * by boot mem after the system is up. So for reusing the resource entry
- * we need to remember the resource.
- */
-static struct resource *bootmem_resource_free;
-static DEFINE_SPINLOCK(bootmem_resource_lock);
-
 static struct resource *next_resource(struct resource *p)
 {
 	if (p->child)
@@ -160,36 +152,19 @@ __initcall(ioresources_init);
 
 static void free_resource(struct resource *res)
 {
-	if (!res)
-		return;
-
-	if (!PageSlab(virt_to_head_page(res))) {
-		spin_lock(&bootmem_resource_lock);
-		res->sibling = bootmem_resource_free;
-		bootmem_resource_free = res;
-		spin_unlock(&bootmem_resource_lock);
-	} else {
+	/**
+	 * If the resource was allocated using memblock early during boot
+	 * we'll leak it here: we can only return full pages back to the
+	 * buddy and trying to be smart and reusing them eventually in
+	 * alloc_resource() overcomplicates resource handling.
+	 */
+	if (res && PageSlab(virt_to_head_page(res)))
 		kfree(res);
-	}
 }
 
 static struct resource *alloc_resource(gfp_t flags)
 {
-	struct resource *res = NULL;
-
-	spin_lock(&bootmem_resource_lock);
-	if (bootmem_resource_free) {
-		res = bootmem_resource_free;
-		bootmem_resource_free = res->sibling;
-	}
-	spin_unlock(&bootmem_resource_lock);
-
-	if (res)
-		memset(res, 0, sizeof(struct resource));
-	else
-		res = kzalloc(sizeof(struct resource), flags);
-
-	return res;
+	return kzalloc(sizeof(struct resource), flags);
 }
 
 /* Return the conflict entry if you can't request it */