Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1704171 > unrolled thread
| Started by | riel@redhat.com |
|---|---|
| First post | 2017-08-04 21:10 +0200 |
| Last post | 2017-08-04 21:30 +0200 |
| Articles | 2 — 2 participants |
Back to article view | Back to linux.kernel
This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by
below is the oldest one visible, not the original post.
[PATCH 1/2] x86,mpx: make mpx depend on x86-64 to free up VMA flag riel@redhat.com - 2017-08-04 21:10 +0200
Re: [PATCH 1/2] x86,mpx: make mpx depend on x86-64 to free up VMA flag Dave Hansen <dave.hansen@intel.com> - 2017-08-04 21:30 +0200
| From | riel@redhat.com |
|---|---|
| Date | 2017-08-04 21:10 +0200 |
| Subject | [PATCH 1/2] x86,mpx: make mpx depend on x86-64 to free up VMA flag |
| Message-ID | <uaQ8W-2CK-15@gated-at.bofh.it> |
From: Rik van Riel <riel@redhat.com> MPX only seems to be available on 64 bit CPUs, starting with Skylake and Goldmont. Move VM_MPX into the 64 bit only portion of vma->vm_flags, in order to free up a VMA flag. Signed-off-by: Rik van Riel <riel@redhat.com> --- arch/x86/Kconfig | 4 +++- include/linux/mm.h | 8 ++++++-- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 781521b7cf9e..6dff14fadc6f 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1756,7 +1756,9 @@ config X86_SMAP config X86_INTEL_MPX prompt "Intel MPX (Memory Protection Extensions)" def_bool n - depends on CPU_SUP_INTEL + # Note: only available in 64-bit mode due to VMA flags shortage + depends on CPU_SUP_INTEL && X86_64 + select ARCH_USES_HIGH_VMA_FLAGS ---help--- MPX provides hardware features that can be used in conjunction with compiler-instrumented code to check diff --git a/include/linux/mm.h b/include/linux/mm.h index 46b9ac5e8569..7550eeb06ccf 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -208,10 +208,12 @@ extern unsigned int kobjsize(const void *objp); #define VM_HIGH_ARCH_BIT_1 33 /* bit only usable on 64-bit architectures */ #define VM_HIGH_ARCH_BIT_2 34 /* bit only usable on 64-bit architectures */ #define VM_HIGH_ARCH_BIT_3 35 /* bit only usable on 64-bit architectures */ +#define VM_HIGH_ARCH_BIT_4 36 /* bit only usable on 64-bit architectures */ #define VM_HIGH_ARCH_0 BIT(VM_HIGH_ARCH_BIT_0) #define VM_HIGH_ARCH_1 BIT(VM_HIGH_ARCH_BIT_1) #define VM_HIGH_ARCH_2 BIT(VM_HIGH_ARCH_BIT_2) #define VM_HIGH_ARCH_3 BIT(VM_HIGH_ARCH_BIT_3) +#define VM_HIGH_ARCH_4 BIT(VM_HIGH_ARCH_BIT_4) #endif /* CONFIG_ARCH_USES_HIGH_VMA_FLAGS */ #if defined(CONFIG_X86) @@ -235,9 +237,11 @@ extern unsigned int kobjsize(const void *objp); # define VM_MAPPED_COPY VM_ARCH_1 /* T if mapped copy of data (nommu mmap) */ #endif -#if defined(CONFIG_X86) +#if defined(CONFIG_X86_INTEL_MPX) /* MPX specific bounds table or bounds directory */ -# define VM_MPX VM_ARCH_2 +# define VM_MPX VM_HIGH_ARCH_BIT_4 +#else +# define VM_MPX VM_NONE #endif #ifndef VM_GROWSUP -- 2.9.4
[toc] | [next] | [standalone]
| From | Dave Hansen <dave.hansen@intel.com> |
|---|---|
| Date | 2017-08-04 21:30 +0200 |
| Subject | Re: [PATCH 1/2] x86,mpx: make mpx depend on x86-64 to free up VMA flag |
| Message-ID | <uaQsh-2J9-1@gated-at.bofh.it> |
| In reply to | #1704171 |
On 08/04/2017 12:07 PM, riel@redhat.com wrote: > MPX only seems to be available on 64 bit CPUs, starting with Skylake > and Goldmont. Move VM_MPX into the 64 bit only portion of vma->vm_flags, > in order to free up a VMA flag. Makes me a little sad. But, seems worth it. Acked-by: Dave Hansen <dave.hansen@intel.com>
[toc] | [prev] | [standalone]
Back to top | Article view | linux.kernel
csiph-web