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From: Dave Hansen <dave.hansen@linux.intel.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, x86@kernel.org,
	kirill.shutemov@linux.intel.com,
	Dave Hansen <dave.hansen@linux.intel.com>
Subject: [RFC][PATCH 1/7] x86, mpx: introduce per-mm MPX table size tracking
Date: Wed, 01 Feb 2017 15:24:09 -0800	[thread overview]
Message-ID: <20170201232409.B089D5ED@viggo.jf.intel.com> (raw)
In-Reply-To: <20170201232408.FA486473@viggo.jf.intel.com>


Larger address spaces mean larger MPX bounds table sizes.  This
tracks which size tables we are using.

"MAWA" is what the hardware documentation calls this feature: MPX
Address-Width Adjust.

---

 b/arch/x86/include/asm/mmu.h |    1 +
 b/arch/x86/include/asm/mpx.h |    6 ++++++
 2 files changed, 7 insertions(+)

diff -puN arch/x86/include/asm/mmu.h~mawa-020-mmu_context-mawa arch/x86/include/asm/mmu.h
--- a/arch/x86/include/asm/mmu.h~mawa-020-mmu_context-mawa	2017-02-01 15:12:15.699124140 -0800
+++ b/arch/x86/include/asm/mmu.h	2017-02-01 15:12:15.702124275 -0800
@@ -34,6 +34,7 @@ typedef struct {
 #ifdef CONFIG_X86_INTEL_MPX
 	/* address of the bounds directory */
 	void __user *bd_addr;
+	int mpx_bd_shift;
 #endif
 } mm_context_t;
 
diff -puN arch/x86/include/asm/mpx.h~mawa-020-mmu_context-mawa arch/x86/include/asm/mpx.h
--- a/arch/x86/include/asm/mpx.h~mawa-020-mmu_context-mawa	2017-02-01 15:12:15.700124185 -0800
+++ b/arch/x86/include/asm/mpx.h	2017-02-01 15:12:15.702124275 -0800
@@ -68,6 +68,12 @@ static inline void mpx_mm_init(struct mm
 	 * directory, so point this at an invalid address.
 	 */
 	mm->context.bd_addr = MPX_INVALID_BOUNDS_DIR;
+	/*
+	 * All processes start out in "legacy" MPX mode with
+	 * the old bounds directory size.  This corresponds to
+	 * what the specs call MAWA=0.
+	 */
+	mm->context.mpx_bd_shift = 0;
 }
 void mpx_notify_unmap(struct mm_struct *mm, struct vm_area_struct *vma,
 		      unsigned long start, unsigned long end);
_

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  reply	other threads:[~2017-02-01 23:24 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-01 23:24 [RFC][PATCH 0/7] x86, mpx: Support larger address space (MAWA) (v2) Dave Hansen
2017-02-01 23:24 ` Dave Hansen [this message]
2017-02-01 23:24 ` [RFC][PATCH 2/7] x86, mpx: update MPX to grok larger bounds tables Dave Hansen
2017-02-12 19:05   ` Thomas Gleixner
2017-02-01 23:24 ` [RFC][PATCH 3/7] x86, mpx: extend MPX prctl() to pass in size of bounds directory Dave Hansen
2017-02-12 19:15   ` Thomas Gleixner
2017-02-01 23:24 ` [RFC][PATCH 4/7] x86, mpx: context-switch new MPX address size MSR Dave Hansen
2017-02-12 19:37   ` Thomas Gleixner
2017-02-01 23:24 ` [RFC][PATCH 5/7] x86, mpx: shrink per-mm MPX data Dave Hansen
2017-02-12 22:44   ` Thomas Gleixner
2017-02-01 23:24 ` [RFC][PATCH 6/7] x86, mpx, selftests: Use prctl header instead of magic numbers Dave Hansen
2017-02-01 23:24 ` [RFC][PATCH 7/7] x86, mpx: update MPX selftest to test larger bounds dir Dave Hansen

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