Merge tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - An extensive rework of kexec and crash Kconfig from Eric DeVolder
   ("refactor Kconfig to consolidate KEXEC and CRASH options")

 - kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
   couple of macros to args.h")

 - gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
   commands")

 - vsprintf inclusion rationalization from Andy Shevchenko
   ("lib/vsprintf: Rework header inclusions")

 - Switch the handling of kdump from a udev scheme to in-kernel
   handling, by Eric DeVolder ("crash: Kernel handling of CPU and memory
   hot un/plug")

 - Many singleton patches to various parts of the tree

* tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (81 commits)
  document while_each_thread(), change first_tid() to use for_each_thread()
  drivers/char/mem.c: shrink character device's devlist[] array
  x86/crash: optimize CPU changes
  crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()
  crash: hotplug support for kexec_load()
  x86/crash: add x86 crash hotplug support
  crash: memory and CPU hotplug sysfs attributes
  kexec: exclude elfcorehdr from the segment digest
  crash: add generic infrastructure for crash hotplug support
  crash: move a few code bits to setup support of crash hotplug
  kstrtox: consistently use _tolower()
  kill do_each_thread()
  nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse
  scripts/bloat-o-meter: count weak symbol sizes
  treewide: drop CONFIG_EMBEDDED
  lockdep: fix static memory detection even more
  lib/vsprintf: declare no_hash_pointers in sprintf.h
  lib/vsprintf: split out sprintf() and friends
  kernel/fork: stop playing lockless games for exe_file replacement
  adfs: delete unused "union adfs_dirtail" definition
  ...

1 files changed, 6 insertions, 37 deletions

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index e2f2574d8b74..9dc728982d79 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -49,9 +49,6 @@
 
 atomic_t __kexec_lock = ATOMIC_INIT(0);
 
-/* Per cpu memory for storing cpu states in case of system crash. */
-note_buf_t __percpu *crash_notes;
-
 /* Flag to indicate we are going to kexec a new kernel */
 bool kexec_in_progress = false;
 
@@ -277,6 +274,12 @@ struct kimage *do_kimage_alloc_init(void)
 	/* Initialize the list of unusable pages */
 	INIT_LIST_HEAD(&image->unusable_pages);
 
+#ifdef CONFIG_CRASH_HOTPLUG
+	image->hp_action = KEXEC_CRASH_HP_NONE;
+	image->elfcorehdr_index = -1;
+	image->elfcorehdr_updated = false;
+#endif
+
 	return image;
 }
 
@@ -1218,40 +1221,6 @@ void crash_save_cpu(struct pt_regs *regs, int cpu)
 	final_note(buf);
 }
 
-static int __init crash_notes_memory_init(void)
-{
-	/* Allocate memory for saving cpu registers. */
-	size_t size, align;
-
-	/*
-	 * crash_notes could be allocated across 2 vmalloc pages when percpu
-	 * is vmalloc based . vmalloc doesn't guarantee 2 continuous vmalloc
-	 * pages are also on 2 continuous physical pages. In this case the
-	 * 2nd part of crash_notes in 2nd page could be lost since only the
-	 * starting address and size of crash_notes are exported through sysfs.
-	 * Here round up the size of crash_notes to the nearest power of two
-	 * and pass it to __alloc_percpu as align value. This can make sure
-	 * crash_notes is allocated inside one physical page.
-	 */
-	size = sizeof(note_buf_t);
-	align = min(roundup_pow_of_two(sizeof(note_buf_t)), PAGE_SIZE);
-
-	/*
-	 * Break compile if size is bigger than PAGE_SIZE since crash_notes
-	 * definitely will be in 2 pages with that.
-	 */
-	BUILD_BUG_ON(size > PAGE_SIZE);
-
-	crash_notes = __alloc_percpu(size, align);
-	if (!crash_notes) {
-		pr_warn("Memory allocation for saving cpu register states failed\n");
-		return -ENOMEM;
-	}
-	return 0;
-}
-subsys_initcall(crash_notes_memory_init);
-
-
 /*
  * Move into place and start executing a preloaded standalone
  * executable.  If nothing was preloaded return an error.