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From: Julien Grall <julien.grall@arm.com>
To: xen-devel@lists.xen.org
Cc: andre.przywara@arm.com, Julien Grall <julien.grall@arm.com>,
	sstabellini@kernel.org, wei.chen@arm.com, steve.capper@arm.com
Subject: [RFC 08/16] xen/arm: arm64: Reserve a brk immediate to fault on purpose
Date: Thu,  5 May 2016 17:34:17 +0100	[thread overview]
Message-ID: <1462466065-30212-9-git-send-email-julien.grall@arm.com> (raw)
In-Reply-To: <1462466065-30212-1-git-send-email-julien.grall@arm.com>

It may not possible to return a proper error when encoding an
instruction. Instead, a handcrafted instruction will be returned.

Also, provide the encoding for the faulting instruction.

Signed-off-by: Julien Grall <julien.grall@arm.com>
---
 xen/include/asm-arm/arm64/brk.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/xen/include/asm-arm/arm64/brk.h b/xen/include/asm-arm/arm64/brk.h
index 7867b07..04442c4 100644
--- a/xen/include/asm-arm/arm64/brk.h
+++ b/xen/include/asm-arm/arm64/brk.h
@@ -12,8 +12,21 @@
 /*
  * #imm16 values used for BRK instruction generation
  * 0x001: xen-mode BUG() and WARN() traps
+ * 0x002: for triggering a fault on purpose (reserved)
  */
 #define BRK_BUG_FRAME_IMM   1
+#define BRK_FAULT_IMM       2
+
+/*
+ * BRK instruction encoding
+ * The #imm16 value should be placed at bits[20:5] within BRK ins
+ */
+#define AARCH64_BREAK_MON 0xd4200000
+
+/*
+ * BRK instruction for provoking a fault on purpose
+ */
+#define AARCH64_BREAK_FAULT (AARCH64_BREAK_MON | (BRK_FAULT_IMM << 5))
 
 #endif /* !__ASM_ARM_ARM64_BRK */
 /*
-- 
1.9.1


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  parent reply	other threads:[~2016-05-05 16:34 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-05 16:34 [RFC 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
2016-05-05 16:34 ` [RFC 01/16] xen/arm: Makefile: Sort the entries alphabetically Julien Grall
2016-05-09  9:34   ` Stefano Stabellini
2016-05-05 16:34 ` [RFC 02/16] xen/arm: Include the header asm-arm/system.h in asm-arm/page.h Julien Grall
2016-05-09  9:34   ` Stefano Stabellini
2016-05-05 16:34 ` [RFC 03/16] xen/arm: Add macros to handle the MIDR Julien Grall
2016-05-09  9:37   ` Stefano Stabellini
2016-05-05 16:34 ` [RFC 04/16] xen/arm: arm64: Import flush_icache_range from Linux v4.6-rc3 Julien Grall
2016-05-09  9:40   ` Julien Grall
2016-05-05 16:34 ` [RFC 05/16] xen/arm: Add cpu_hwcap bitmap Julien Grall
2016-05-09  9:53   ` Stefano Stabellini
2016-05-09 10:02     ` Julien Grall
2016-05-05 16:34 ` [RFC 06/16] xen/arm64: Add an helper to invalidate all instruction caches Julien Grall
2016-05-09  9:50   ` Stefano Stabellini
2016-05-05 16:34 ` [RFC 07/16] xen/arm: arm64: Move the define BRK_BUG_FRAME into a separate header Julien Grall
2016-05-09  9:55   ` Stefano Stabellini
2016-05-05 16:34 ` Julien Grall [this message]
2016-05-09  9:58   ` [RFC 08/16] xen/arm: arm64: Reserve a brk immediate to fault on purpose Stefano Stabellini
2016-05-05 16:34 ` [RFC 09/16] xen/arm: arm64: Add helpers to decode and encode branch instructions Julien Grall
2016-05-09 10:05   ` Stefano Stabellini
2016-05-09 13:04     ` Julien Grall
2016-05-23 10:52       ` Julien Grall
2016-05-13 20:35   ` Konrad Rzeszutek Wilk
2016-05-14 10:49     ` Julien Grall
2016-05-05 16:34 ` [RFC 10/16] xen/arm: Introduce alternative runtime patching Julien Grall
2016-05-13 20:26   ` Konrad Rzeszutek Wilk
2016-05-14 18:02     ` Julien Grall
2016-05-21 15:09   ` Stefano Stabellini
2016-05-23 11:11     ` Julien Grall
2016-05-30 14:45       ` Stefano Stabellini
2016-05-30 16:42         ` Julien Grall
2016-05-31  9:21           ` Stefano Stabellini
2016-05-31 10:24             ` Julien Grall
2016-06-02 14:46               ` Konrad Rzeszutek Wilk
2016-06-02 15:04                 ` Julien Grall
2016-06-02 15:14                   ` Julien Grall
2016-06-06 14:17                     ` Konrad Rzeszutek Wilk
2016-06-06 14:18                       ` Julien Grall
2016-05-05 16:34 ` [RFC 11/16] xen/arm: Detect silicon revision and set cap bits accordingly Julien Grall
2016-05-13 20:37   ` Konrad Rzeszutek Wilk
2016-05-14 18:04     ` Julien Grall
2016-05-16 13:50       ` Konrad Rzeszutek Wilk
2016-05-16 13:54         ` Julien Grall
2016-05-05 16:34 ` [RFC 12/16] xen/arm: Document the errata implemented in Xen Julien Grall
2016-05-05 16:34 ` [RFC 13/16] xen/arm: arm64: Add Cortex-A53 cache errata workaround Julien Grall
2016-05-21 14:40   ` Stefano Stabellini
2016-05-23 13:39     ` Julien Grall
2016-05-05 16:34 ` [RFC 14/16] xen/arm: arm64: Add cortex-A57 erratum 832075 workaround Julien Grall
2016-05-05 16:34 ` [RFC 15/16] xen/arm: traps: Don't inject a fault if the translation VA -> IPA fails Julien Grall
2016-05-21 14:42   ` Stefano Stabellini
2016-05-21 14:51     ` Stefano Stabellini
2016-05-23 13:45       ` Julien Grall
2016-05-05 16:34 ` [RFC 16/16] xen/arm: arm64: Document Cortex-A57 erratum 834220 Julien Grall
2016-05-05 16:38 ` [RFC 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
2016-05-11  2:28 ` Wei Chen

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