Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Along with the usual shower of singleton patches, notable patch series
  in this pull request are:

   - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
     consistency to the APIs and behaviour of these two core allocation
     functions. This also simplifies/enables Rustification.

   - "Some cleanups for shmem" from Baolin Wang. No functional changes -
     mode code reuse, better function naming, logic simplifications.

   - "mm: some small page fault cleanups" from Josef Bacik. No
     functional changes - code cleanups only.

   - "Various memory tiering fixes" from Zi Yan. A small fix and a
     little cleanup.

   - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
     simplifications and .text shrinkage.

   - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
     Butt. This is a feature, it adds new feilds to /proc/vmstat such as

       $ grep kstack /proc/vmstat
       kstack_1k 3
       kstack_2k 188
       kstack_4k 11391
       kstack_8k 243
       kstack_16k 0

     which tells us that 11391 processes used 4k of stack while none at
     all used 16k. Useful for some system tuning things, but
     partivularly useful for "the dynamic kernel stack project".

   - "kmemleak: support for percpu memory leak detect" from Pavel
     Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.

   - "mm: memcg: page counters optimizations" from Roman Gushchin. "3
     independent small optimizations of page counters".

   - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
     David Hildenbrand. Improves PTE/PMD splitlock detection, makes
     powerpc/8xx work correctly by design rather than by accident.

   - "mm: remove arch_make_page_accessible()" from David Hildenbrand.
     Some folio conversions which make arch_make_page_accessible()
     unneeded.

   - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
     Finkel. Cleans up and fixes our handling of the resetting of the
     cgroup/process peak-memory-use detector.

   - "Make core VMA operations internal and testable" from Lorenzo
     Stoakes. Rationalizaion and encapsulation of the VMA manipulation
     APIs. With a view to better enable testing of the VMA functions,
     even from a userspace-only harness.

   - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
     issues in the zswap global shrinker, resulting in improved
     performance.

   - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
     in some missing info in /proc/zoneinfo.

   - "mm: replace follow_page() by folio_walk" from David Hildenbrand.
     Code cleanups and rationalizations (conversion to folio_walk())
     resulting in the removal of follow_page().

   - "improving dynamic zswap shrinker protection scheme" from Nhat
     Pham. Some tuning to improve zswap's dynamic shrinker. Significant
     reductions in swapin and improvements in performance are shown.

   - "mm: Fix several issues with unaccepted memory" from Kirill
     Shutemov. Improvements to the new unaccepted memory feature,

   - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
     DAX PUDs. This was missing, although nobody seems to have notied
     yet.

   - "Introduce a store type enum for the Maple tree" from Sidhartha
     Kumar. Cleanups and modest performance improvements for the maple
     tree library code.

   - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
     more cgroup v1 remnants away from the v2 memcg code.

   - "memcg: initiate deprecation of v1 features" from Shakeel Butt.
     Adds various warnings telling users that memcg v1 features are
     deprecated.

   - "mm: swap: mTHP swap allocator base on swap cluster order" from
     Chris Li. Greatly improves the success rate of the mTHP swap
     allocation.

   - "mm: introduce numa_memblks" from Mike Rapoport. Moves various
     disparate per-arch implementations of numa_memblk code into generic
     code.

   - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
     improves the performance of munmap() of swap-filled ptes.

   - "support large folio swap-out and swap-in for shmem" from Baolin
     Wang. With this series we no longer split shmem large folios into
     simgle-page folios when swapping out shmem.

   - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
     performance improvements and code reductions for gigantic folios.

   - "support shmem mTHP collapse" from Baolin Wang. Adds support for
     khugepaged's collapsing of shmem mTHP folios.

   - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
     performance regression due to the addition of mseal().

   - "Increase the number of bits available in page_type" from Matthew
     Wilcox. Increases the number of bits available in page_type!

   - "Simplify the page flags a little" from Matthew Wilcox. Many legacy
     page flags are now folio flags, so the page-based flags and their
     accessors/mutators can be removed.

   - "mm: store zero pages to be swapped out in a bitmap" from Usama
     Arif. An optimization which permits us to avoid writing/reading
     zero-filled zswap pages to backing store.

   - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
     window which occurs when a MAP_FIXED operqtion is occurring during
     an unrelated vma tree walk.

   - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
     the vma_merge() functionality, making ot cleaner, more testable and
     better tested.

   - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
     Minor fixups of DAMON selftests and kunit tests.

   - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
     Code cleanups and folio conversions.

   - "Shmem mTHP controls and stats improvements" from Ryan Roberts.
     Cleanups for shmem controls and stats.

   - "mm: count the number of anonymous THPs per size" from Barry Song.
     Expose additional anon THP stats to userspace for improved tuning.

   - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
     folio conversions and removal of now-unused page-based APIs.

   - "replace per-quota region priorities histogram buffer with
     per-context one" from SeongJae Park. DAMON histogram
     rationalization.

   - "Docs/damon: update GitHub repo URLs and maintainer-profile" from
     SeongJae Park. DAMON documentation updates.

   - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
     improve related doc and warn" from Jason Wang: fixes usage of page
     allocator __GFP_NOFAIL and GFP_ATOMIC flags.

   - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
     This was overprovisioning THPs in sparsely accessed memory areas.

   - "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
     Add support for zram run-time compression algorithm tuning.

   - "mm: Care about shadow stack guard gap when getting an unmapped
     area" from Mark Brown. Fix up the various arch_get_unmapped_area()
     implementations to better respect guard areas.

   - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
     of mem_cgroup_iter() and various code cleanups.

   - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
     pfnmap support.

   - "resource: Fix region_intersects() vs add_memory_driver_managed()"
     from Huang Ying. Fix a bug in region_intersects() for systems with
     CXL memory.

   - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
     a couple more code paths to correctly recover from the encountering
     of poisoned memry.

   - "mm: enable large folios swap-in support" from Barry Song. Support
     the swapin of mTHP memory into appropriately-sized folios, rather
     than into single-page folios"

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area->pages[2] into xol_area->page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...

12 files changed, 67 insertions, 61 deletions

diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig
index 6001d580c0dd..a5e3e7f97f4d 100644
--- a/arch/powerpc/configs/ppc64_defconfig
+++ b/arch/powerpc/configs/ppc64_defconfig
@@ -81,7 +81,6 @@ CONFIG_MODULE_SIG_SHA512=y
 CONFIG_PARTITION_ADVANCED=y
 CONFIG_BINFMT_MISC=m
 CONFIG_ZSWAP=y
-CONFIG_Z3FOLD=y
 CONFIG_ZSMALLOC=y
 # CONFIG_SLAB_MERGE_DEFAULT is not set
 CONFIG_SLAB_FREELIST_RANDOM=y
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index f8ba72573cae..6d98e6f08d4d 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -1098,6 +1098,7 @@ extern pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot);
 extern pud_t pfn_pud(unsigned long pfn, pgprot_t pgprot);
 extern pmd_t mk_pmd(struct page *page, pgprot_t pgprot);
 extern pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot);
+extern pud_t pud_modify(pud_t pud, pgprot_t newprot);
 extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 		       pmd_t *pmdp, pmd_t pmd);
 extern void set_pud_at(struct mm_struct *mm, unsigned long addr,
@@ -1358,6 +1359,8 @@ static inline pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm,
 #define __HAVE_ARCH_PMDP_INVALIDATE
 extern pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
 			     pmd_t *pmdp);
+extern pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
+			     pud_t *pudp);
 
 #define pmd_move_must_withdraw pmd_move_must_withdraw
 struct spinlock;
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 99707456c2cd..a157ab513347 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -257,15 +257,6 @@ static inline void enter_lazy_tlb(struct mm_struct *mm,
 
 extern void arch_exit_mmap(struct mm_struct *mm);
 
-static inline void arch_unmap(struct mm_struct *mm,
-			      unsigned long start, unsigned long end)
-{
-	unsigned long vdso_base = (unsigned long)mm->context.vdso;
-
-	if (start <= vdso_base && vdso_base < end)
-		mm->context.vdso = NULL;
-}
-
 #ifdef CONFIG_PPC_MEM_KEYS
 bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
 			       bool execute, bool foreign);
diff --git a/arch/powerpc/include/asm/mmzone.h b/arch/powerpc/include/asm/mmzone.h
index da827d2d0866..d99863cd6cde 100644
--- a/arch/powerpc/include/asm/mmzone.h
+++ b/arch/powerpc/include/asm/mmzone.h
@@ -20,12 +20,6 @@
 
 #ifdef CONFIG_NUMA
 
-extern struct pglist_data *node_data[];
-/*
- * Return a pointer to the node data for node n.
- */
-#define NODE_DATA(nid)		(node_data[nid])
-
 /*
  * Following are specific to this numa platform.
  */
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 264a6c09517a..2f72ad885332 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -65,6 +65,7 @@ static inline unsigned long pte_pfn(pte_t pte)
 /*
  * Select all bits except the pfn
  */
+#define pte_pgprot pte_pgprot
 static inline pgprot_t pte_pgprot(pte_t pte)
 {
 	unsigned long pte_flags;
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 7a2ff9010f17..ee4b9d676cff 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -81,6 +81,21 @@ static int vdso64_mremap(const struct vm_special_mapping *sm, struct vm_area_str
 	return vdso_mremap(sm, new_vma, &vdso64_end - &vdso64_start);
 }
 
+static void vdso_close(const struct vm_special_mapping *sm, struct vm_area_struct *vma)
+{
+	struct mm_struct *mm = vma->vm_mm;
+
+	/*
+	 * close() is called for munmap() but also for mremap(). In the mremap()
+	 * case the vdso pointer has already been updated by the mremap() hook
+	 * above, so it must not be set to NULL here.
+	 */
+	if (vma->vm_start != (unsigned long)mm->context.vdso)
+		return;
+
+	mm->context.vdso = NULL;
+}
+
 static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 			     struct vm_area_struct *vma, struct vm_fault *vmf);
 
@@ -92,11 +107,13 @@ static struct vm_special_mapping vvar_spec __ro_after_init = {
 static struct vm_special_mapping vdso32_spec __ro_after_init = {
 	.name = "[vdso]",
 	.mremap = vdso32_mremap,
+	.close = vdso_close,
 };
 
 static struct vm_special_mapping vdso64_spec __ro_after_init = {
 	.name = "[vdso]",
 	.mremap = vdso64_mremap,
+	.close = vdso_close,
 };
 
 #ifdef CONFIG_TIME_NS
@@ -197,13 +214,6 @@ static int __arch_setup_additional_pages(struct linux_binprm *bprm, int uses_int
 	/* Add required alignment. */
 	vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
 
-	/*
-	 * Put vDSO base into mm struct. We need to do this before calling
-	 * install_special_mapping or the perf counter mmap tracking code
-	 * will fail to recognise it as a vDSO.
-	 */
-	mm->context.vdso = (void __user *)vdso_base + vvar_size;
-
 	vma = _install_special_mapping(mm, vdso_base, vvar_size,
 				       VM_READ | VM_MAYREAD | VM_IO |
 				       VM_DONTDUMP | VM_PFNMAP, &vvar_spec);
@@ -223,10 +233,15 @@ static int __arch_setup_additional_pages(struct linux_binprm *bprm, int uses_int
 	vma = _install_special_mapping(mm, vdso_base + vvar_size, vdso_size,
 				       VM_READ | VM_EXEC | VM_MAYREAD |
 				       VM_MAYWRITE | VM_MAYEXEC, vdso_spec);
-	if (IS_ERR(vma))
+	if (IS_ERR(vma)) {
 		do_munmap(mm, vdso_base, vvar_size, NULL);
+		return PTR_ERR(vma);
+	}
+
+	// Now that the mappings are in place, set the mm VDSO pointer
+	mm->context.vdso = (void __user *)vdso_base + vvar_size;
 
-	return PTR_ERR_OR_ZERO(vma);
+	return 0;
 }
 
 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
@@ -240,8 +255,6 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 		return -EINTR;
 
 	rc = __arch_setup_additional_pages(bprm, uses_interp);
-	if (rc)
-		mm->context.vdso = NULL;
 
 	mmap_write_unlock(mm);
 	return rc;
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index f4d8d3c40e5c..5a4a75369043 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -176,6 +176,17 @@ pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
 	return __pmd(old_pmd);
 }
 
+pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
+		      pud_t *pudp)
+{
+	unsigned long old_pud;
+
+	VM_WARN_ON_ONCE(!pud_present(*pudp));
+	old_pud = pud_hugepage_update(vma->vm_mm, address, pudp, _PAGE_PRESENT, _PAGE_INVALID);
+	flush_pud_tlb_range(vma, address, address + HPAGE_PUD_SIZE);
+	return __pud(old_pud);
+}
+
 pmd_t pmdp_huge_get_and_clear_full(struct vm_area_struct *vma,
 				   unsigned long addr, pmd_t *pmdp, int full)
 {
@@ -259,6 +270,15 @@ pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
 	pmdv &= _HPAGE_CHG_MASK;
 	return pmd_set_protbits(__pmd(pmdv), newprot);
 }
+
+pud_t pud_modify(pud_t pud, pgprot_t newprot)
+{
+	unsigned long pudv;
+
+	pudv = pud_val(pud);
+	pudv &= _HPAGE_CHG_MASK;
+	return pud_set_protbits(__pud(pudv), newprot);
+}
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 /* For use by kexec, called with MMU off */
diff --git a/arch/powerpc/mm/book3s64/slice.c b/arch/powerpc/mm/book3s64/slice.c
index ef3ce37f1bb3..87307d0fc3b8 100644
--- a/arch/powerpc/mm/book3s64/slice.c
+++ b/arch/powerpc/mm/book3s64/slice.c
@@ -637,10 +637,11 @@ unsigned long arch_get_unmapped_area(struct file *filp,
 				     unsigned long addr,
 				     unsigned long len,
 				     unsigned long pgoff,
-				     unsigned long flags)
+				     unsigned long flags,
+				     vm_flags_t vm_flags)
 {
 	if (radix_enabled())
-		return generic_get_unmapped_area(filp, addr, len, pgoff, flags);
+		return generic_get_unmapped_area(filp, addr, len, pgoff, flags, vm_flags);
 
 	return slice_get_unmapped_area(addr, len, flags,
 				       mm_ctx_user_psize(&current->mm->context), 0);
@@ -650,10 +651,11 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp,
 					     const unsigned long addr0,
 					     const unsigned long len,
 					     const unsigned long pgoff,
-					     const unsigned long flags)
+					     const unsigned long flags,
+					     vm_flags_t vm_flags)
 {
 	if (radix_enabled())
-		return generic_get_unmapped_area_topdown(filp, addr0, len, pgoff, flags);
+		return generic_get_unmapped_area_topdown(filp, addr0, len, pgoff, flags, vm_flags);
 
 	return slice_get_unmapped_area(addr0, len, flags,
 				       mm_ctx_user_psize(&current->mm->context), 1);
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index aa89899f0c1a..3c1da08304d0 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -43,11 +43,9 @@ static char *cmdline __initdata;
 
 int numa_cpu_lookup_table[NR_CPUS];
 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
-struct pglist_data *node_data[MAX_NUMNODES];
 
 EXPORT_SYMBOL(numa_cpu_lookup_table);
 EXPORT_SYMBOL(node_to_cpumask_map);
-EXPORT_SYMBOL(node_data);
 
 static int primary_domain_index;
 static int n_mem_addr_cells, n_mem_size_cells;
@@ -1095,27 +1093,9 @@ void __init dump_numa_cpu_topology(void)
 static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
 {
 	u64 spanned_pages = end_pfn - start_pfn;
-	const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);
-	u64 nd_pa;
-	void *nd;
-	int tnid;
-
-	nd_pa = memblock_phys_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
-	if (!nd_pa)
-		panic("Cannot allocate %zu bytes for node %d data\n",
-		      nd_size, nid);
-
-	nd = __va(nd_pa);
-
-	/* report and initialize */
-	pr_info("  NODE_DATA [mem %#010Lx-%#010Lx]\n",
-		nd_pa, nd_pa + nd_size - 1);
-	tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
-	if (tnid != nid)
-		pr_info("    NODE_DATA(%d) on node %d\n", nid, tnid);
-
-	node_data[nid] = nd;
-	memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
+
+	alloc_node_data(nid);
+
 	NODE_DATA(nid)->node_id = nid;
 	NODE_DATA(nid)->node_start_pfn = start_pfn;
 	NODE_DATA(nid)->node_spanned_pages = spanned_pages;
diff --git a/arch/powerpc/mm/pgtable-frag.c b/arch/powerpc/mm/pgtable-frag.c
index 8c31802f97e8..e89f64a0f24a 100644
--- a/arch/powerpc/mm/pgtable-frag.c
+++ b/arch/powerpc/mm/pgtable-frag.c
@@ -136,10 +136,10 @@ void pte_fragment_free(unsigned long *table, int kernel)
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 void pte_free_defer(struct mm_struct *mm, pgtable_t pgtable)
 {
-	struct page *page;
+	struct folio *folio;
 
-	page = virt_to_page(pgtable);
-	SetPageActive(page);
+	folio = virt_to_folio(pgtable);
+	folio_set_active(folio);
 	pte_fragment_free((unsigned long *)pgtable, 0);
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index ab0656115424..7316396e452d 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -297,6 +297,12 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 }
 
 #if defined(CONFIG_PPC_8xx)
+
+#if defined(CONFIG_SPLIT_PTE_PTLOCKS) || defined(CONFIG_SPLIT_PMD_PTLOCKS)
+/* We need the same lock to protect the PMD table and the two PTE tables. */
+#error "8M hugetlb folios are incompatible with split page table locks"
+#endif
+
 static void __set_huge_pte_at(pmd_t *pmd, pte_t *ptep, pte_basic_t val)
 {
 	pte_basic_t *entry = (pte_basic_t *)ptep;
diff --git a/arch/powerpc/platforms/pseries/papr-vpd.c b/arch/powerpc/platforms/pseries/papr-vpd.c
index c29e85db5f35..1574176e3ffc 100644
--- a/arch/powerpc/platforms/pseries/papr-vpd.c
+++ b/arch/powerpc/platforms/pseries/papr-vpd.c
@@ -156,10 +156,7 @@ static int vpd_blob_extend(struct vpd_blob *blob, const char *data, size_t len)
 	const char *old_ptr = blob->data;
 	char *new_ptr;
 
-	new_ptr = old_ptr ?
-		kvrealloc(old_ptr, old_len, new_len, GFP_KERNEL_ACCOUNT) :
-		kvmalloc(len, GFP_KERNEL_ACCOUNT);
-
+	new_ptr = kvrealloc(old_ptr, new_len, GFP_KERNEL_ACCOUNT);
 	if (!new_ptr)
 		return -ENOMEM;