linux-kernel - [PATCHv4 09/12] arm64: Check for selected granule support

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]

Message-Id: <1445015181-29711-10-git-send-email-suzuki.poulose@arm.com>
Date:	Fri, 16 Oct 2015 18:06:18 +0100
From:	"Suzuki K. Poulose" <suzuki.poulose@....com>
To:	linux-arm-kernel@...ts.infradead.org
Cc:	catalin.marinas@....com, mark.rutland@....com,
	marc.zyngier@....com, will.deacon@....com,
	linux-kernel@...r.kernel.org, ard.biesheuvel@...aro.org,
	chirstoff.dall@...aro.org, steve.capper@...aro.org,
	jeremy.linton@....com, "Suzuki K. Poulose" <suzuki.poulose@....com>
Subject: [PATCHv4 09/12] arm64: Check for selected granule support

Ensure that the selected page size is supported by the CPU(s). If it doesn't
park it.

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/sysreg.h |   20 ++++++++++++++++++++
 arch/arm64/kernel/head.S        |   17 +++++++++++++++--
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index a7f3d4b..d59cb23 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -44,6 +44,26 @@
 #define SET_PSTATE_PAN(x) __inst_arm(0xd5000000 | REG_PSTATE_PAN_IMM |\
 				     (!!x)<<8 | 0x1f)
 
+
+#define ID_AA64MMFR0_TGRAN4_SHIFT	28
+#define ID_AA64MMFR0_TGRAN64_SHIFT	24
+#define ID_AA64MMFR0_TGRAN16_SHIFT	20
+
+#define ID_AA64MMFR0_TGRAN4_NI		0xf
+#define ID_AA64MMFR0_TGRAN4_SUPPORTED	0x0
+#define ID_AA64MMFR0_TGRAN64_NI		0xf
+#define ID_AA64MMFR0_TGRAN64_SUPPORTED	0x0
+#define ID_AA64MMFR0_TGRAN16_NI		0x0
+#define ID_AA64MMFR0_TGRAN16_SUPPORTED	0x1
+
+#if defined(CONFIG_ARM64_4K_PAGES)
+#define ID_AA64MMFR0_TGRAN_SHIFT	ID_AA64MMFR0_TGRAN4_SHIFT
+#define ID_AA64MMFR0_TGRAN_SUPPORTED	ID_AA64MMFR0_TGRAN4_SUPPORTED
+#elif defined(CONFIG_ARM64_64K_PAGES)
+#define ID_AA64MMFR0_TGRAN_SHIFT	ID_AA64MMFR0_TGRAN64_SHIFT
+#define ID_AA64MMFR0_TGRAN_SUPPORTED	ID_AA64MMFR0_TGRAN64_SUPPORTED
+#endif
+
 #ifdef __ASSEMBLY__
 
 	.irp	num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 7ace955..514c1cc 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -31,10 +31,11 @@
 #include <asm/cputype.h>
 #include <asm/kernel-pgtable.h>
 #include <asm/memory.h>
-#include <asm/thread_info.h>
 #include <asm/pgtable-hwdef.h>
 #include <asm/pgtable.h>
 #include <asm/page.h>
+#include <asm/sysreg.h>
+#include <asm/thread_info.h>
 #include <asm/virt.h>
 
 #define __PHYS_OFFSET	(KERNEL_START - TEXT_OFFSET)
@@ -613,10 +614,17 @@ ENDPROC(__secondary_switched)
  *  x0  = SCTLR_EL1 value for turning on the MMU.
  *  x27 = *virtual* address to jump to upon completion
  *
- * other registers depend on the function called upon completion
+ * Other registers depend on the function called upon completion.
+ *
+ * Checks if the selected granule size is supported by the CPU.
+ * If it isn't, park the CPU
  */
 	.section	".idmap.text", "ax"
 __enable_mmu:
+	mrs	x1, ID_AA64MMFR0_EL1
+	ubfx	x2, x1, #ID_AA64MMFR0_TGRAN_SHIFT, 4
+	cmp	x2, #ID_AA64MMFR0_TGRAN_SUPPORTED
+	b.ne	__no_granule_support
 	ldr	x5, =vectors
 	msr	vbar_el1, x5
 	msr	ttbr0_el1, x25			// load TTBR0
@@ -634,3 +642,8 @@ __enable_mmu:
 	isb
 	br	x27
 ENDPROC(__enable_mmu)
+
+__no_granule_support:
+	wfe
+	b __no_granule_support
+ENDPROC(__no_granule_support)
-- 
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/