From: Ard Biesheuvel <ardb@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Ard Biesheuvel <ardb@kernel.org>, Marc Zyngier <maz@kernel.org>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Kees Cook <keescook@chromium.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Brown <broonie@kernel.org>,
Anshuman Khandual <anshuman.khandual@arm.com>
Subject: [PATCH v6 4/9] arm64: head: allocate more pages for the kernel mapping
Date: Fri, 1 Jul 2022 15:04:39 +0200 [thread overview]
Message-ID: <20220701130444.2945106-5-ardb@kernel.org> (raw)
In-Reply-To: <20220701130444.2945106-1-ardb@kernel.org>
In preparation for switching to an early kernel mapping routine that
maps each segment according to its precise boundaries, and with the
correct attributes, let's allocate some extra pages for page tables for
the 4k page size configuration. This is necessary because the start and
end of each segment may not be aligned to the block size, and so we'll
need an extra page table at each segment boundary.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/arm64/include/asm/kernel-pgtable.h | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h
index 02e59fa8f293..5b63bdcd0741 100644
--- a/arch/arm64/include/asm/kernel-pgtable.h
+++ b/arch/arm64/include/asm/kernel-pgtable.h
@@ -85,7 +85,7 @@
+ EARLY_PGDS((vstart), (vend)) /* each PGDIR needs a next level page table */ \
+ EARLY_PUDS((vstart), (vend)) /* each PUD needs a next level page table */ \
+ EARLY_PMDS((vstart), (vend))) /* each PMD needs a next level page table */
-#define INIT_DIR_SIZE (PAGE_SIZE * EARLY_PAGES(KIMAGE_VADDR, _end))
+#define INIT_DIR_SIZE (PAGE_SIZE * (EARLY_PAGES(KIMAGE_VADDR, _end) + EARLY_SEGMENT_EXTRA_PAGES))
/* the initial ID map may need two extra pages if it needs to be extended */
#if VA_BITS < 48
@@ -106,6 +106,15 @@
#define SWAPPER_TABLE_SHIFT PMD_SHIFT
#endif
+/* The number of segments in the kernel image (text, rodata, inittext, initdata, data+bss) */
+#define KERNEL_SEGMENT_COUNT 5
+
+#if SWAPPER_BLOCK_SIZE > SEGMENT_ALIGN
+#define EARLY_SEGMENT_EXTRA_PAGES (KERNEL_SEGMENT_COUNT + 1)
+#else
+#define EARLY_SEGMENT_EXTRA_PAGES 0
+#endif
+
/*
* Initial memory map attributes.
*/
--
2.35.1
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next prev parent reply other threads:[~2022-07-01 13:07 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-01 13:04 [PATCH v6 0/9] arm64: add support for WXN Ard Biesheuvel
2022-07-01 13:04 ` [PATCH v6 1/9] arm64: kaslr: use an ordinary command line param for nokaslr Ard Biesheuvel
2022-07-01 14:07 ` Mark Brown
2022-07-01 13:04 ` [PATCH v6 2/9] arm64: kaslr: don't pretend KASLR is enabled if offset < MIN_KIMG_ALIGN Ard Biesheuvel
2022-07-01 14:12 ` Mark Brown
2022-07-01 13:04 ` [PATCH v6 3/9] arm64: kaslr: drop special case for ThunderX in kaslr_requires_kpti() Ard Biesheuvel
2022-07-01 13:04 ` Ard Biesheuvel [this message]
2022-07-01 13:04 ` [PATCH v6 5/9] arm64: head: move early kernel mapping and relocation code to C code Ard Biesheuvel
2022-07-01 13:04 ` [PATCH v6 6/9] arm64: mm: avoid fixmap for early swapper_pg_dir updates Ard Biesheuvel
2022-07-01 13:04 ` [PATCH v6 7/9] arm64: mm: omit redundant remap of kernel image Ard Biesheuvel
2022-07-01 13:04 ` [PATCH v6 8/9] mm: add arch hook to validate mmap() prot flags Ard Biesheuvel
2022-07-01 13:04 ` [PATCH v6 9/9] arm64: mm: add support for WXN memory translation attribute Ard Biesheuvel
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