Merge tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
   from hotplugged memory rather than only from main memory. Series
   "implement "memmap on memory" feature on s390".

 - More folio conversions from Matthew Wilcox in the series

	"Convert memcontrol charge moving to use folios"
	"mm: convert mm counter to take a folio"

 - Chengming Zhou has optimized zswap's rbtree locking, providing
   significant reductions in system time and modest but measurable
   reductions in overall runtimes. The series is "mm/zswap: optimize the
   scalability of zswap rb-tree".

 - Chengming Zhou has also provided the series "mm/zswap: optimize zswap
   lru list" which provides measurable runtime benefits in some
   swap-intensive situations.

 - And Chengming Zhou further optimizes zswap in the series "mm/zswap:
   optimize for dynamic zswap_pools". Measured improvements are modest.

 - zswap cleanups and simplifications from Yosry Ahmed in the series
   "mm: zswap: simplify zswap_swapoff()".

 - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
   contributed several DAX cleanups as well as adding a sysfs tunable to
   control the memmap_on_memory setting when the dax device is
   hotplugged as system memory.

 - Johannes Weiner has added the large series "mm: zswap: cleanups",
   which does that.

 - More DAMON work from SeongJae Park in the series

	"mm/damon: make DAMON debugfs interface deprecation unignorable"
	"selftests/damon: add more tests for core functionalities and corner cases"
	"Docs/mm/damon: misc readability improvements"
	"mm/damon: let DAMOS feeds and tame/auto-tune itself"

 - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
   extension" Rakie Kim has developed a new mempolicy interleaving
   policy wherein we allocate memory across nodes in a weighted fashion
   rather than uniformly. This is beneficial in heterogeneous memory
   environments appearing with CXL.

 - Christophe Leroy has contributed some cleanup and consolidation work
   against the ARM pagetable dumping code in the series "mm: ptdump:
   Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".

 - Luis Chamberlain has added some additional xarray selftesting in the
   series "test_xarray: advanced API multi-index tests".

 - Muhammad Usama Anjum has reworked the selftest code to make its
   human-readable output conform to the TAP ("Test Anything Protocol")
   format. Amongst other things, this opens up the use of third-party
   tools to parse and process out selftesting results.

 - Ryan Roberts has added fork()-time PTE batching of THP ptes in the
   series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
   targeted at arm64, this significantly speeds up fork() when the
   process has a large number of pte-mapped folios.

 - David Hildenbrand also gets in on the THP pte batching game in his
   series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
   implements batching during munmap() and other pte teardown
   situations. The microbenchmark improvements are nice.

 - And in the series "Transparent Contiguous PTEs for User Mappings"
   Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
   mappings"). Kernel build times on arm64 improved nicely. Ryan's
   series "Address some contpte nits" provides some followup work.

 - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
   fixed an obscure hugetlb race which was causing unnecessary page
   faults. He has also added a reproducer under the selftest code.

 - In the series "selftests/mm: Output cleanups for the compaction
   test", Mark Brown did what the title claims.

 - Kinsey Ho has added the series "mm/mglru: code cleanup and
   refactoring".

 - Even more zswap material from Nhat Pham. The series "fix and extend
   zswap kselftests" does as claimed.

 - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
   regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
   in our handling of DAX on archiecctures which have virtually aliasing
   data caches. The arm architecture is the main beneficiary.

 - Lokesh Gidra's series "per-vma locks in userfaultfd" provides
   dramatic improvements in worst-case mmap_lock hold times during
   certain userfaultfd operations.

 - Some page_owner enhancements and maintenance work from Oscar Salvador
   in his series

	"page_owner: print stacks and their outstanding allocations"
	"page_owner: Fixup and cleanup"

 - Uladzislau Rezki has contributed some vmalloc scalability
   improvements in his series "Mitigate a vmap lock contention". It
   realizes a 12x improvement for a certain microbenchmark.

 - Some kexec/crash cleanup work from Baoquan He in the series "Split
   crash out from kexec and clean up related config items".

 - Some zsmalloc maintenance work from Chengming Zhou in the series

	"mm/zsmalloc: fix and optimize objects/page migration"
	"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"

 - Zi Yan has taught the MM to perform compaction on folios larger than
   order=0. This a step along the path to implementaton of the merging
   of large anonymous folios. The series is named "Enable >0 order folio
   memory compaction".

 - Christoph Hellwig has done quite a lot of cleanup work in the
   pagecache writeback code in his series "convert write_cache_pages()
   to an iterator".

 - Some modest hugetlb cleanups and speedups in Vishal Moola's series
   "Handle hugetlb faults under the VMA lock".

 - Zi Yan has changed the page splitting code so we can split huge pages
   into sizes other than order-0 to better utilize large folios. The
   series is named "Split a folio to any lower order folios".

 - David Hildenbrand has contributed the series "mm: remove
   total_mapcount()", a cleanup.

 - Matthew Wilcox has sought to improve the performance of bulk memory
   freeing in his series "Rearrange batched folio freeing".

 - Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
   provides large improvements in bootup times on large machines which
   are configured to use large numbers of hugetlb pages.

 - Matthew Wilcox's series "PageFlags cleanups" does that.

 - Qi Zheng's series "minor fixes and supplement for ptdesc" does that
   also. S390 is affected.

 - Cleanups to our pagemap utility functions from Peter Xu in his series
   "mm/treewide: Replace pXd_large() with pXd_leaf()".

 - Nico Pache has fixed a few things with our hugepage selftests in his
   series "selftests/mm: Improve Hugepage Test Handling in MM
   Selftests".

 - Also, of course, many singleton patches to many things. Please see
   the individual changelogs for details.

* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
  mm/zswap: remove the memcpy if acomp is not sleepable
  crypto: introduce: acomp_is_async to expose if comp drivers might sleep
  memtest: use {READ,WRITE}_ONCE in memory scanning
  mm: prohibit the last subpage from reusing the entire large folio
  mm: recover pud_leaf() definitions in nopmd case
  selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
  selftests/mm: skip uffd hugetlb tests with insufficient hugepages
  selftests/mm: dont fail testsuite due to a lack of hugepages
  mm/huge_memory: skip invalid debugfs new_order input for folio split
  mm/huge_memory: check new folio order when split a folio
  mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
  mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
  mm: fix list corruption in put_pages_list
  mm: remove folio from deferred split list before uncharging it
  filemap: avoid unnecessary major faults in filemap_fault()
  mm,page_owner: drop unnecessary check
  mm,page_owner: check for null stack_record before bumping its refcount
  mm: swap: fix race between free_swap_and_cache() and swapoff()
  mm/treewide: align up pXd_leaf() retval across archs
  mm/treewide: drop pXd_large()
  ...

1 files changed, 12 insertions, 238 deletions

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index d08fc7b5db97..ce3429e7972c 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -54,30 +54,6 @@ bool kexec_in_progress = false;
 
 bool kexec_file_dbg_print;
 
-int kexec_should_crash(struct task_struct *p)
-{
-	/*
-	 * If crash_kexec_post_notifiers is enabled, don't run
-	 * crash_kexec() here yet, which must be run after panic
-	 * notifiers in panic().
-	 */
-	if (crash_kexec_post_notifiers)
-		return 0;
-	/*
-	 * There are 4 panic() calls in make_task_dead() path, each of which
-	 * corresponds to each of these 4 conditions.
-	 */
-	if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops)
-		return 1;
-	return 0;
-}
-
-int kexec_crash_loaded(void)
-{
-	return !!kexec_crash_image;
-}
-EXPORT_SYMBOL_GPL(kexec_crash_loaded);
-
 /*
  * When kexec transitions to the new kernel there is a one-to-one
  * mapping between physical and virtual addresses.  On processors
@@ -209,6 +185,7 @@ int sanity_check_segment_list(struct kimage *image)
 	if (total_pages > nr_pages / 2)
 		return -EINVAL;
 
+#ifdef CONFIG_CRASH_DUMP
 	/*
 	 * Verify we have good destination addresses.  Normally
 	 * the caller is responsible for making certain we don't
@@ -231,6 +208,7 @@ int sanity_check_segment_list(struct kimage *image)
 				return -EADDRNOTAVAIL;
 		}
 	}
+#endif
 
 	return 0;
 }
@@ -403,6 +381,7 @@ static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
 	return pages;
 }
 
+#ifdef CONFIG_CRASH_DUMP
 static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
 						      unsigned int order)
 {
@@ -468,6 +447,7 @@ static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
 
 	return pages;
 }
+#endif
 
 
 struct page *kimage_alloc_control_pages(struct kimage *image,
@@ -479,48 +459,16 @@ struct page *kimage_alloc_control_pages(struct kimage *image,
 	case KEXEC_TYPE_DEFAULT:
 		pages = kimage_alloc_normal_control_pages(image, order);
 		break;
+#ifdef CONFIG_CRASH_DUMP
 	case KEXEC_TYPE_CRASH:
 		pages = kimage_alloc_crash_control_pages(image, order);
 		break;
+#endif
 	}
 
 	return pages;
 }
 
-int kimage_crash_copy_vmcoreinfo(struct kimage *image)
-{
-	struct page *vmcoreinfo_page;
-	void *safecopy;
-
-	if (image->type != KEXEC_TYPE_CRASH)
-		return 0;
-
-	/*
-	 * For kdump, allocate one vmcoreinfo safe copy from the
-	 * crash memory. as we have arch_kexec_protect_crashkres()
-	 * after kexec syscall, we naturally protect it from write
-	 * (even read) access under kernel direct mapping. But on
-	 * the other hand, we still need to operate it when crash
-	 * happens to generate vmcoreinfo note, hereby we rely on
-	 * vmap for this purpose.
-	 */
-	vmcoreinfo_page = kimage_alloc_control_pages(image, 0);
-	if (!vmcoreinfo_page) {
-		pr_warn("Could not allocate vmcoreinfo buffer\n");
-		return -ENOMEM;
-	}
-	safecopy = vmap(&vmcoreinfo_page, 1, VM_MAP, PAGE_KERNEL);
-	if (!safecopy) {
-		pr_warn("Could not vmap vmcoreinfo buffer\n");
-		return -ENOMEM;
-	}
-
-	image->vmcoreinfo_data_copy = safecopy;
-	crash_update_vmcoreinfo_safecopy(safecopy);
-
-	return 0;
-}
-
 static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
 {
 	if (*image->entry != 0)
@@ -603,10 +551,12 @@ void kimage_free(struct kimage *image)
 	if (!image)
 		return;
 
+#ifdef CONFIG_CRASH_DUMP
 	if (image->vmcoreinfo_data_copy) {
 		crash_update_vmcoreinfo_safecopy(NULL);
 		vunmap(image->vmcoreinfo_data_copy);
 	}
+#endif
 
 	kimage_free_extra_pages(image);
 	for_each_kimage_entry(image, ptr, entry) {
@@ -824,6 +774,7 @@ out:
 	return result;
 }
 
+#ifdef CONFIG_CRASH_DUMP
 static int kimage_load_crash_segment(struct kimage *image,
 					struct kexec_segment *segment)
 {
@@ -891,6 +842,7 @@ static int kimage_load_crash_segment(struct kimage *image,
 out:
 	return result;
 }
+#endif
 
 int kimage_load_segment(struct kimage *image,
 				struct kexec_segment *segment)
@@ -901,9 +853,11 @@ int kimage_load_segment(struct kimage *image,
 	case KEXEC_TYPE_DEFAULT:
 		result = kimage_load_normal_segment(image, segment);
 		break;
+#ifdef CONFIG_CRASH_DUMP
 	case KEXEC_TYPE_CRASH:
 		result = kimage_load_crash_segment(image, segment);
 		break;
+#endif
 	}
 
 	return result;
@@ -1028,186 +982,6 @@ bool kexec_load_permitted(int kexec_image_type)
 }
 
 /*
- * No panic_cpu check version of crash_kexec().  This function is called
- * only when panic_cpu holds the current CPU number; this is the only CPU
- * which processes crash_kexec routines.
- */
-void __noclone __crash_kexec(struct pt_regs *regs)
-{
-	/* Take the kexec_lock here to prevent sys_kexec_load
-	 * running on one cpu from replacing the crash kernel
-	 * we are using after a panic on a different cpu.
-	 *
-	 * If the crash kernel was not located in a fixed area
-	 * of memory the xchg(&kexec_crash_image) would be
-	 * sufficient.  But since I reuse the memory...
-	 */
-	if (kexec_trylock()) {
-		if (kexec_crash_image) {
-			struct pt_regs fixed_regs;
-
-			crash_setup_regs(&fixed_regs, regs);
-			crash_save_vmcoreinfo();
-			machine_crash_shutdown(&fixed_regs);
-			machine_kexec(kexec_crash_image);
-		}
-		kexec_unlock();
-	}
-}
-STACK_FRAME_NON_STANDARD(__crash_kexec);
-
-__bpf_kfunc void crash_kexec(struct pt_regs *regs)
-{
-	int old_cpu, this_cpu;
-
-	/*
-	 * Only one CPU is allowed to execute the crash_kexec() code as with
-	 * panic().  Otherwise parallel calls of panic() and crash_kexec()
-	 * may stop each other.  To exclude them, we use panic_cpu here too.
-	 */
-	old_cpu = PANIC_CPU_INVALID;
-	this_cpu = raw_smp_processor_id();
-
-	if (atomic_try_cmpxchg(&panic_cpu, &old_cpu, this_cpu)) {
-		/* This is the 1st CPU which comes here, so go ahead. */
-		__crash_kexec(regs);
-
-		/*
-		 * Reset panic_cpu to allow another panic()/crash_kexec()
-		 * call.
-		 */
-		atomic_set(&panic_cpu, PANIC_CPU_INVALID);
-	}
-}
-
-static inline resource_size_t crash_resource_size(const struct resource *res)
-{
-	return !res->end ? 0 : resource_size(res);
-}
-
-ssize_t crash_get_memory_size(void)
-{
-	ssize_t size = 0;
-
-	if (!kexec_trylock())
-		return -EBUSY;
-
-	size += crash_resource_size(&crashk_res);
-	size += crash_resource_size(&crashk_low_res);
-
-	kexec_unlock();
-	return size;
-}
-
-static int __crash_shrink_memory(struct resource *old_res,
-				 unsigned long new_size)
-{
-	struct resource *ram_res;
-
-	ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
-	if (!ram_res)
-		return -ENOMEM;
-
-	ram_res->start = old_res->start + new_size;
-	ram_res->end   = old_res->end;
-	ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
-	ram_res->name  = "System RAM";
-
-	if (!new_size) {
-		release_resource(old_res);
-		old_res->start = 0;
-		old_res->end   = 0;
-	} else {
-		crashk_res.end = ram_res->start - 1;
-	}
-
-	crash_free_reserved_phys_range(ram_res->start, ram_res->end);
-	insert_resource(&iomem_resource, ram_res);
-
-	return 0;
-}
-
-int crash_shrink_memory(unsigned long new_size)
-{
-	int ret = 0;
-	unsigned long old_size, low_size;
-
-	if (!kexec_trylock())
-		return -EBUSY;
-
-	if (kexec_crash_image) {
-		ret = -ENOENT;
-		goto unlock;
-	}
-
-	low_size = crash_resource_size(&crashk_low_res);
-	old_size = crash_resource_size(&crashk_res) + low_size;
-	new_size = roundup(new_size, KEXEC_CRASH_MEM_ALIGN);
-	if (new_size >= old_size) {
-		ret = (new_size == old_size) ? 0 : -EINVAL;
-		goto unlock;
-	}
-
-	/*
-	 * (low_size > new_size) implies that low_size is greater than zero.
-	 * This also means that if low_size is zero, the else branch is taken.
-	 *
-	 * If low_size is greater than 0, (low_size > new_size) indicates that
-	 * crashk_low_res also needs to be shrunken. Otherwise, only crashk_res
-	 * needs to be shrunken.
-	 */
-	if (low_size > new_size) {
-		ret = __crash_shrink_memory(&crashk_res, 0);
-		if (ret)
-			goto unlock;
-
-		ret = __crash_shrink_memory(&crashk_low_res, new_size);
-	} else {
-		ret = __crash_shrink_memory(&crashk_res, new_size - low_size);
-	}
-
-	/* Swap crashk_res and crashk_low_res if needed */
-	if (!crashk_res.end && crashk_low_res.end) {
-		crashk_res.start = crashk_low_res.start;
-		crashk_res.end   = crashk_low_res.end;
-		release_resource(&crashk_low_res);
-		crashk_low_res.start = 0;
-		crashk_low_res.end   = 0;
-		insert_resource(&iomem_resource, &crashk_res);
-	}
-
-unlock:
-	kexec_unlock();
-	return ret;
-}
-
-void crash_save_cpu(struct pt_regs *regs, int cpu)
-{
-	struct elf_prstatus prstatus;
-	u32 *buf;
-
-	if ((cpu < 0) || (cpu >= nr_cpu_ids))
-		return;
-
-	/* Using ELF notes here is opportunistic.
-	 * I need a well defined structure format
-	 * for the data I pass, and I need tags
-	 * on the data to indicate what information I have
-	 * squirrelled away.  ELF notes happen to provide
-	 * all of that, so there is no need to invent something new.
-	 */
-	buf = (u32 *)per_cpu_ptr(crash_notes, cpu);
-	if (!buf)
-		return;
-	memset(&prstatus, 0, sizeof(prstatus));
-	prstatus.common.pr_pid = current->pid;
-	elf_core_copy_regs(&prstatus.pr_reg, regs);
-	buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
-			      &prstatus, sizeof(prstatus));
-	final_note(buf);
-}
-
-/*
  * Move into place and start executing a preloaded standalone
  * executable.  If nothing was preloaded return an error.
  */