From mboxrd@z Thu Jan 1 00:00:00 1970 From: riel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org Subject: [PATCH 1/2] x86,mpx: make mpx depend on x86-64 to free up VMA flag Date: Fri, 11 Aug 2017 15:19:41 -0400 Message-ID: <20170811191942.17487-2-riel@redhat.com> References: <20170811191942.17487-1-riel@redhat.com> Return-path: In-Reply-To: <20170811191942.17487-1-riel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, mike.kravetz-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, fweimer-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, colm-ZXBCfW2eEe/k1uMJSBkQmQ@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org, wad-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, kirill-oKw7cIdHH8eLwutG50LtGA@public.gmane.org, dave.hansen-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org List-Id: linux-api@vger.kernel.org From: Rik van Riel 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 Acked-by: Dave Hansen --- 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