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From: mark.rutland@arm.com (Mark Rutland)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 3/6] arm64: pad stacks to PAGE_SIZE for VMAP_STACK
Date: Wed, 12 Jul 2017 23:33:00 +0100	[thread overview]
Message-ID: <1499898783-25732-4-git-send-email-mark.rutland@arm.com> (raw)
In-Reply-To: <1499898783-25732-1-git-send-email-mark.rutland@arm.com>

Our THREAD_SIZE may be smaller than PAGE_SIZE. With VMAP_STACK, we can't
allow stacks to share a page with anything else, so may as well pad
up-to PAGE_SIZE, and have 64K stacks when we have 64K pages.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/thread_info.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 6d0c59a..3684f86 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -25,7 +25,13 @@
 
 #include <asm/page.h>
 
-#define THREAD_SHIFT		14
+#define __THREAD_SHIFT		14
+
+#if defined(CONFIG_VMAP_STACK) && (__THREAD_SHIFT < PAGE_SHIFT)
+#define THREAD_SHIFT		PAGE_SHIFT
+#else
+#define THREAD_SHIFT		__THREAD_SHIFT
+#endif
 
 #if THREAD_SHIFT >= PAGE_SHIFT
 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
-- 
1.9.1

  parent reply	other threads:[~2017-07-12 22:33 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-12 22:32 [RFC PATCH 0/6] arm64: alternative VMAP_STACK implementation Mark Rutland
2017-07-12 22:32 ` [RFC PATCH 1/6] arm64: use tpidr_el1 for current, free sp_el0 Mark Rutland
2017-07-14  1:30   ` Will Deacon
2017-07-12 22:32 ` [RFC PATCH 2/6] arm64: avoid open-coding THREAD_SIZE{,_ORDER} Mark Rutland
2017-07-13 10:18   ` James Morse
2017-07-13 11:26     ` Mark Rutland
2017-07-12 22:33 ` Mark Rutland [this message]
2017-07-12 22:33 ` [RFC PATCH 4/6] arm64: pass stack base to secondary_start_kernel Mark Rutland
2017-07-12 22:33 ` [RFC PATCH 5/6] arm64: keep track of current stack Mark Rutland
2017-07-12 22:33 ` [RFC PATCH 6/6] arm64: add VMAP_STACK and detect out-of-bounds SP Mark Rutland
2017-07-13  6:58   ` Ard Biesheuvel
2017-07-13 10:49     ` Mark Rutland
2017-07-13 11:49       ` Ard Biesheuvel
2017-07-13 16:10         ` Mark Rutland
2017-07-13 17:55           ` [kernel-hardening] " Mark Rutland
2017-07-13 18:28             ` Ard Biesheuvel
2017-07-14 10:32               ` Mark Rutland
2017-07-14 10:48                 ` Ard Biesheuvel
2017-07-14 12:27                   ` Ard Biesheuvel
2017-07-14 14:06                     ` Mark Rutland
2017-07-14 14:14                       ` Ard Biesheuvel
2017-07-14 14:39                       ` Robin Murphy
2017-07-14 15:03                         ` Robin Murphy
2017-07-14 15:15                           ` Ard Biesheuvel
2017-07-14 15:25                           ` Mark Rutland
2017-07-14 21:27                       ` Mark Rutland
2017-07-16  0:03                         ` Ard Biesheuvel
2017-07-18 21:53                           ` Laura Abbott
2017-07-19  8:08                             ` Ard Biesheuvel
     [not found]                               ` <aa086315-722b-bff3-90bb-f479229ed104@redhat.com>
2017-07-20  5:35                                 ` Ard Biesheuvel
2017-07-20  8:36                                   ` James Morse
2017-07-20  8:56                                     ` Ard Biesheuvel
2017-07-20 17:30                                       ` Ard Biesheuvel
2017-07-20 19:10                                         ` Laura Abbott
2017-07-14 12:52                   ` Mark Rutland
2017-07-14 12:55                     ` Ard Biesheuvel

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