From: "Liam R. Howlett" <Liam.Howlett@oracle.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Suren Baghdasaryan <surenb@google.com>,
Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
Pedro Falcato <pfalcato@suse.de>,
David Hildenbrand <david@redhat.com>,
Vlastimil Babka <vbabka@suse.cz>, Michal Hocko <mhocko@suse.com>,
Jann Horn <jannh@google.com>,
shikemeng@huaweicloud.com, kasong@tencent.com, nphamcs@gmail.com,
bhe@redhat.com, baohua@kernel.org, chrisl@kernel.org,
Matthew Wilcox <willy@infradead.org>,
"Liam R. Howlett" <Liam.Howlett@oracle.com>,
SeongJae Park <sj@kernel.org>
Subject: [PATCH v3 01/11] mm: Relocate the page table ceiling and floor definitions
Date: Wed, 21 Jan 2026 11:49:36 -0500 [thread overview]
Message-ID: <20260121164946.2093480-2-Liam.Howlett@oracle.com> (raw)
In-Reply-To: <20260121164946.2093480-1-Liam.Howlett@oracle.com>
pgtables.h defines a fallback for ceiling and floor of the page tables
within the CONFIG_MMU section. Moving the definitions to outside the
CONFIG_MMU Allows for using them in generic code.
Suggested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Suggested-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---
include/linux/pgtable.h | 39 ++++++++++++++++++++-------------------
mm/vma_internal.h | 1 +
2 files changed, 21 insertions(+), 19 deletions(-)
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index eb8aacba3698d..557ac918bdca6 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -22,25 +22,6 @@
#error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{P4D,PUD,PMD}_FOLDED
#endif
-/*
- * On almost all architectures and configurations, 0 can be used as the
- * upper ceiling to free_pgtables(): on many architectures it has the same
- * effect as using TASK_SIZE. However, there is one configuration which
- * must impose a more careful limit, to avoid freeing kernel pgtables.
- */
-#ifndef USER_PGTABLES_CEILING
-#define USER_PGTABLES_CEILING 0UL
-#endif
-
-/*
- * This defines the first usable user address. Platforms
- * can override its value with custom FIRST_USER_ADDRESS
- * defined in their respective <asm/pgtable.h>.
- */
-#ifndef FIRST_USER_ADDRESS
-#define FIRST_USER_ADDRESS 0UL
-#endif
-
/*
* This defines the generic helper for accessing PMD page
* table page. Although platforms can still override this
@@ -1660,6 +1641,26 @@ void arch_sync_kernel_mappings(unsigned long start, unsigned long end);
#endif /* CONFIG_MMU */
+/*
+ * On almost all architectures and configurations, 0 can be used as the
+ * upper ceiling to free_pgtables(): on many architectures it has the same
+ * effect as using TASK_SIZE. However, there is one configuration which
+ * must impose a more careful limit, to avoid freeing kernel pgtables.
+ */
+#ifndef USER_PGTABLES_CEILING
+#define USER_PGTABLES_CEILING 0UL
+#endif
+
+/*
+ * This defines the first usable user address. Platforms
+ * can override its value with custom FIRST_USER_ADDRESS
+ * defined in their respective <asm/pgtable.h>.
+ */
+#ifndef FIRST_USER_ADDRESS
+#define FIRST_USER_ADDRESS 0UL
+#endif
+
+
/*
* No-op macros that just return the current protection value. Defined here
* because these macros can be used even if CONFIG_MMU is not defined.
diff --git a/mm/vma_internal.h b/mm/vma_internal.h
index 2f05735ff190c..2da6d224c1a85 100644
--- a/mm/vma_internal.h
+++ b/mm/vma_internal.h
@@ -46,6 +46,7 @@
#include <linux/swap.h>
#include <linux/uprobes.h>
#include <linux/userfaultfd_k.h>
+#include <linux/pgtable.h>
#include <asm/current.h>
#include <asm/tlb.h>
--
2.47.3
next prev parent reply other threads:[~2026-01-21 16:51 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-21 16:49 [PATCH v3 00/11] Remove XA_ZERO from error recovery of dup_mmap() Liam R. Howlett
2026-01-21 16:49 ` Liam R. Howlett [this message]
2026-01-21 17:26 ` [PATCH v3 01/11] mm: Relocate the page table ceiling and floor definitions SeongJae Park
2026-01-21 18:52 ` Liam R. Howlett
2026-01-21 16:49 ` [PATCH v3 02/11] mm/mmap: Move exit_mmap() trace point Liam R. Howlett
2026-01-21 16:49 ` [PATCH v3 03/11] mm/mmap: Abstract vma clean up from exit_mmap() Liam R. Howlett
2026-01-21 16:49 ` [PATCH v3 04/11] mm/vma: Add limits to unmap_region() for vmas Liam R. Howlett
2026-01-21 16:49 ` [PATCH v3 05/11] mm/memory: Add tree limit to free_pgtables() Liam R. Howlett
2026-01-21 16:49 ` [PATCH v3 06/11] mm/vma: Add page table limit to unmap_region() Liam R. Howlett
2026-01-21 16:49 ` [PATCH v3 07/11] mm: Change dup_mmap() recovery Liam R. Howlett
2026-01-21 16:49 ` [PATCH v3 08/11] mm: Introduce unmap_desc struct to reduce function arguments Liam R. Howlett
2026-01-21 16:49 ` [PATCH v3 09/11] mm/vma: Use unmap_desc in exit_mmap() and vms_clear_ptes() Liam R. Howlett
2026-01-21 16:49 ` [PATCH v3 10/11] mm/vma: Use unmap_region() in vms_clear_ptes() Liam R. Howlett
2026-01-21 16:49 ` [PATCH v3 11/11] mm: Use unmap_desc struct for freeing page tables Liam R. Howlett
2026-01-24 18:45 ` Chris Mason
2026-02-07 12:37 ` Liam R. Howlett
2026-02-10 20:41 ` Liam R. Howlett
2026-02-10 21:42 ` [PATCH] mm: Fix up unmap desc use on exit_mmap() Liam R. Howlett
2026-01-21 18:59 ` [PATCH v3 00/11] Remove XA_ZERO from error recovery of dup_mmap() Andrew Morton
2026-01-21 19:34 ` Liam R. Howlett
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