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From: Dan Williams <dan.j.williams@intel.com>
To: linux-kernel@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
	linux-arch@vger.kernel.org, kernel-hardening@lists.openwall.com,
	tglx@linutronix.de, torvalds@linux-foundation.org,
	akpm@linux-foundation.org, alan@linux.intel.com
Subject: [PATCH v2 03/19] arm: implement ifence_array_ptr()
Date: Thu, 11 Jan 2018 16:46:40 -0800	[thread overview]
Message-ID: <151571800075.27429.5000616446434113763.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
In-Reply-To: <151571798296.27429.7166552848688034184.stgit@dwillia2-desk3.amr.corp.intel.com>

From: Mark Rutland <mark.rutland@arm.com>

This patch implements ifence_array_ptr() for arm, using an
LDR+MOVCS+CSDB sequence to inhibit speculative use of the returned
value.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/arm/include/asm/barrier.h |   24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/arch/arm/include/asm/barrier.h b/arch/arm/include/asm/barrier.h
index 40f5c410fd8c..919235ed6e68 100644
--- a/arch/arm/include/asm/barrier.h
+++ b/arch/arm/include/asm/barrier.h
@@ -59,6 +59,30 @@ extern void arm_heavy_mb(void);
 #define dma_wmb()	barrier()
 #endif
 
+#define ifence_array_ptr(arr, idx, sz)					\
+({									\
+	typeof(&(arr)[0]) __nap_arr = (arr);				\
+	typeof(idx) __nap_idx = (idx);					\
+	typeof(sz) __nap_sz = (sz);					\
+									\
+	unsigned long __nap_ptr = (unsigned long)__nap_arr +		\
+				  sizeof(__nap_arr[0]) * idx;		\
+									\
+	asm volatile(							\
+	"	cmp	%[i], %[s]\n"					\
+	"	bcs	1f\n"						\
+	"	ldr	%[p], %[pp]\n"					\
+	"1:	movcs	%[p], #0\n"					\
+	"	.inst	0xe320f018 @ CSDB\n"				\
+	: [p] "=&r" (__nap_ptr)						\
+	: [pp] "m" (__nap_ptr),						\
+	  [i] "r" ((unsigned long)__nap_idx),				\
+	  [s] "r" ((unsigned long)__nap_sz)				\
+	: "cc");							\
+									\
+	(typeof(&(__nap_arr)[0]))__nap_ptr;				\
+})
+
 #define __smp_mb()	dmb(ish)
 #define __smp_rmb()	__smp_mb()
 #define __smp_wmb()	dmb(ishst)

  parent reply	other threads:[~2018-01-12  1:00 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-12  0:46 [PATCH v2 00/19] prevent bounds-check bypass via speculative execution Dan Williams
2018-01-12  0:46 ` [PATCH v2 01/19] Documentation: document array_ptr Dan Williams
2018-01-12 10:38   ` Geert Uytterhoeven
2018-01-16 21:01   ` Kees Cook
2018-01-12  0:46 ` [PATCH v2 02/19] arm64: implement ifence_array_ptr() Dan Williams
2018-01-12  0:46 ` Dan Williams [this message]
2018-01-12  0:46 ` [PATCH v2 04/19] x86: implement ifence() Dan Williams
2018-01-12  2:27   ` Eric W. Biederman
2018-01-12  3:39     ` Dan Williams
2018-01-12  0:46 ` [PATCH v2 05/19] x86: implement ifence_array_ptr() and array_ptr_mask() Dan Williams
2018-01-12  0:46 ` [PATCH v2 06/19] asm-generic/barrier: mask speculative execution flows Dan Williams
2018-01-12  2:42   ` Eric W. Biederman
2018-01-12  9:12   ` Peter Zijlstra
2018-01-13  0:41     ` Dan Williams
2018-01-15  8:46       ` Peter Zijlstra
2018-01-12  0:47 ` [PATCH v2 07/19] x86: introduce __uaccess_begin_nospec and ASM_IFENCE Dan Williams
2018-01-12 17:51   ` Josh Poimboeuf
2018-01-12 18:21     ` Dan Williams
2018-01-12 18:58       ` Josh Poimboeuf
2018-01-12 19:26         ` Dan Williams
2018-01-12 20:01           ` Linus Torvalds
2018-01-12 20:41             ` Josh Poimboeuf
2018-01-12  0:47 ` [PATCH v2 08/19] x86: use __uaccess_begin_nospec and ASM_IFENCE in get_user paths Dan Williams
2018-01-12  1:11   ` Linus Torvalds
2018-01-12  1:14     ` Dan Williams
2018-01-12  0:47 ` [PATCH v2 09/19] ipv6: prevent bounds-check bypass via speculative execution Dan Williams
2018-01-12  0:47 ` [PATCH v2 10/19] ipv4: " Dan Williams
2018-01-12  7:59   ` Greg KH
2018-01-12 18:47     ` Dan Williams
2018-01-13  8:56       ` Greg KH
2018-01-12  0:47 ` [PATCH v2 11/19] vfs, fdtable: " Dan Williams
2018-01-12  0:47 ` [PATCH v2 12/19] userns: " Dan Williams
2018-01-12  0:47 ` [PATCH v2 13/19] udf: " Dan Williams
2018-01-15 10:32   ` Jan Kara
2018-01-15 17:49     ` Dan Williams
2018-01-12  0:47 ` [PATCH v2 14/19] [media] uvcvideo: " Dan Williams
2018-08-06 21:40   ` Laurent Pinchart
2018-01-12  0:47 ` [PATCH v2 15/19] carl9170: " Dan Williams
2018-01-12 14:42   ` Christian Lamparter
2018-01-12 18:39     ` Dan Williams
2018-01-12 20:01       ` Christian Lamparter
2018-01-12 23:05         ` Dan Williams
2018-01-12  0:47 ` [PATCH v2 16/19] p54: " Dan Williams
2018-01-12  0:47 ` [PATCH v2 17/19] qla2xxx: " Dan Williams
2018-01-12  1:19   ` James Bottomley
2018-01-12  5:38     ` Dan Williams
2018-01-12  6:05       ` James Bottomley
2018-01-12  0:48 ` [PATCH v2 18/19] cw1200: " Dan Williams
2018-01-12  0:48 ` [PATCH v2 19/19] net: mpls: " Dan Williams
2018-01-12  1:19 ` [PATCH v2 00/19] " Linus Torvalds
2018-01-12  1:41   ` Dan Williams
2018-01-18 13:18     ` Will Deacon
2018-01-18 16:58       ` Dan Williams
2018-01-18 17:05         ` Will Deacon
2018-01-18 21:41           ` Laurent Pinchart
2018-01-13  0:15   ` Tony Luck
2018-01-13 18:51     ` Linus Torvalds
2018-01-16 19:21       ` Tony Luck
2018-01-12 10:02 ` Russell King - ARM Linux

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