linux-kernel - [PATCHv3 04/11] arm64: Calculate size for idmap_pg

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 14 Oct 2015 12:20:27 +0100
From:	"Suzuki K. Poulose" <suzuki.poulose@....com>
To:	linux-arm-kernel@...ts.infradead.org
Cc:	linux-kernel@...r.kernel.org, catalin.marinas@....com,
	will.deacon@....com, mark.rutland@....com, steve.capper@...aro.org,
	marc.zyngier@....com, ard.biesheuvel@...aro.org,
	christoffer.dall@...aro.org,
	"Suzuki K. Poulose" <suzuki.poulose@....com>
Subject: [PATCHv3 04/11] arm64: Calculate size for idmap_pg_dir at compile time

Now that we can calculate the number of levels required for
mapping a va width, reserve exact number of pages that would
be required to cover the idmap. The idmap should be able to handle
the maximum physical address size supported.

Cc: Ard Biesheuvel <ard.biesheuvel@...aro.org>
Cc: Mark Rutland <mark.rutland@....com>
Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will.deacon@....com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@....com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
---
 arch/arm64/include/asm/kernel-pgtable.h |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h
index 5876a36..def7168 100644
--- a/arch/arm64/include/asm/kernel-pgtable.h
+++ b/arch/arm64/include/asm/kernel-pgtable.h
@@ -33,16 +33,19 @@
  * map to pte level. The swapper also maps the FDT (see __create_page_tables
  * for more information). Note that the number of ID map translation levels
  * could be increased on the fly if system RAM is out of reach for the default
- * VA range, so 3 pages are reserved in all cases.
+ * VA range, so pages required to map highest possible PA are reserved in all
+ * cases.
  */
 #if ARM64_SWAPPER_USES_SECTION_MAPS
 #define SWAPPER_PGTABLE_LEVELS	(CONFIG_PGTABLE_LEVELS - 1)
+#define IDMAP_PGTABLE_LEVELS	(ARM64_HW_PGTABLE_LEVELS(PHYS_MASK_SHIFT) - 1)
 #else
 #define SWAPPER_PGTABLE_LEVELS	(CONFIG_PGTABLE_LEVELS)
+#define IDMAP_PGTABLE_LEVELS	(ARM64_HW_PGTABLE_LEVELS(PHYS_MASK_SHIFT))
 #endif
 
 #define SWAPPER_DIR_SIZE	(SWAPPER_PGTABLE_LEVELS * PAGE_SIZE)
-#define IDMAP_DIR_SIZE		(3 * PAGE_SIZE)
+#define IDMAP_DIR_SIZE		(IDMAP_PGTABLE_LEVELS * PAGE_SIZE)
 
 /* Initial memory map size */
 #if ARM64_SWAPPER_USES_SECTION_MAPS
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/