From: Dave Hansen <dave@sr71.net> To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, luto@kernel.org, mgorman@techsingularity.net, Dave Hansen <dave@sr71.net>, dave.hansen@linux.intel.com, arnd@arndb.de Subject: [PATCH 01/10] x86, pkeys: add fault handling for PF_PK page fault bit Date: Fri, 29 Jul 2016 09:30:10 -0700 [thread overview] Message-ID: <20160729163010.DD1FE1ED@viggo.jf.intel.com> (raw) In-Reply-To: <20160729163009.5EC1D38C@viggo.jf.intel.com> From: Dave Hansen <dave.hansen@linux.intel.com> PF_PK means that a memory access violated the protection key access restrictions. It is unconditionally an access_error() because the permissions set on the VMA don't matter (the PKRU value overrides it), and we never "resolve" PK faults (like how a COW can "resolve write fault). Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Cc: x86@kernel.org Cc: torvalds@linux-foundation.org Cc: akpm@linux-foundation.org Cc: Arnd Bergmann <arnd@arndb.de> --- b/arch/x86/mm/fault.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff -puN arch/x86/mm/fault.c~pkeys-105-add-pk-to-fault arch/x86/mm/fault.c --- a/arch/x86/mm/fault.c~pkeys-105-add-pk-to-fault 2016-07-29 09:18:55.920448993 -0700 +++ b/arch/x86/mm/fault.c 2016-07-29 09:18:55.923449129 -0700 @@ -1112,6 +1112,15 @@ access_error(unsigned long error_code, s { /* This is only called for the current mm, so: */ bool foreign = false; + + /* + * Read or write was blocked by protection keys. This is + * always an unconditional error and can never result in + * a follow-up action to resolve the fault, like a COW. + */ + if (error_code & PF_PK) + return 1; + /* * Make sure to check the VMA so that we do not perform * faults just to hit a PF_PK as soon as we fill in a _
WARNING: multiple messages have this Message-ID (diff)
From: Dave Hansen <dave@sr71.net> To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, luto@kernel.org, mgorman@techsingularity.net, Dave Hansen <dave@sr71.net>, dave.hansen@linux.intel.com, arnd@arndb.de Subject: [PATCH 01/10] x86, pkeys: add fault handling for PF_PK page fault bit Date: Fri, 29 Jul 2016 09:30:10 -0700 [thread overview] Message-ID: <20160729163010.DD1FE1ED@viggo.jf.intel.com> (raw) In-Reply-To: <20160729163009.5EC1D38C@viggo.jf.intel.com> From: Dave Hansen <dave.hansen@linux.intel.com> PF_PK means that a memory access violated the protection key access restrictions. It is unconditionally an access_error() because the permissions set on the VMA don't matter (the PKRU value overrides it), and we never "resolve" PK faults (like how a COW can "resolve write fault). Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Cc: x86@kernel.org Cc: torvalds@linux-foundation.org Cc: akpm@linux-foundation.org Cc: Arnd Bergmann <arnd@arndb.de> --- b/arch/x86/mm/fault.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff -puN arch/x86/mm/fault.c~pkeys-105-add-pk-to-fault arch/x86/mm/fault.c --- a/arch/x86/mm/fault.c~pkeys-105-add-pk-to-fault 2016-07-29 09:18:55.920448993 -0700 +++ b/arch/x86/mm/fault.c 2016-07-29 09:18:55.923449129 -0700 @@ -1112,6 +1112,15 @@ access_error(unsigned long error_code, s { /* This is only called for the current mm, so: */ bool foreign = false; + + /* + * Read or write was blocked by protection keys. This is + * always an unconditional error and can never result in + * a follow-up action to resolve the fault, like a COW. + */ + if (error_code & PF_PK) + return 1; + /* * Make sure to check the VMA so that we do not perform * faults just to hit a PF_PK as soon as we fill in a _ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2016-07-29 16:30 UTC|newest] Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-07-29 16:30 [PATCH 00/10] [v6] System Calls for Memory Protection Keys Dave Hansen 2016-07-29 16:30 ` Dave Hansen 2016-07-29 16:30 ` Dave Hansen [this message] 2016-07-29 16:30 ` [PATCH 01/10] x86, pkeys: add fault handling for PF_PK page fault bit Dave Hansen 2016-09-09 11:10 ` [tip:mm/pkeys] x86/pkeys: Add " tip-bot for Dave Hansen 2016-07-29 16:30 ` [PATCH 02/10] mm: implement new pkey_mprotect() system call Dave Hansen 2016-07-29 16:30 ` Dave Hansen 2016-09-09 11:11 ` [tip:mm/pkeys] mm: Implement " tip-bot for Dave Hansen 2016-07-29 16:30 ` [PATCH 03/10] x86, pkeys: make mprotect_key() mask off additional vm_flags Dave Hansen 2016-07-29 16:30 ` Dave Hansen 2016-09-09 11:11 ` [tip:mm/pkeys] x86/pkeys: Make " tip-bot for Dave Hansen 2016-07-29 16:30 ` [PATCH 04/10] x86, pkeys: allocation/free syscalls Dave Hansen 2016-07-29 16:30 ` Dave Hansen 2016-09-09 11:12 ` [tip:mm/pkeys] x86/pkeys: Allocation/free syscalls tip-bot for Dave Hansen 2016-07-29 16:30 ` [PATCH 05/10] x86: wire up protection keys system calls Dave Hansen 2016-07-29 16:30 ` Dave Hansen 2016-07-29 16:30 ` Dave Hansen 2016-09-09 11:12 ` [tip:mm/pkeys] x86: Wire " tip-bot for Dave Hansen 2016-07-29 16:30 ` [PATCH 06/10] generic syscalls: wire up memory protection keys syscalls Dave Hansen 2016-07-29 16:30 ` Dave Hansen 2016-09-09 11:12 ` [tip:mm/pkeys] generic syscalls: Wire " tip-bot for Dave Hansen 2016-07-29 16:30 ` [PATCH 07/10] pkeys: add details of system call use to Documentation/ Dave Hansen 2016-07-29 16:30 ` Dave Hansen 2016-09-09 11:13 ` [tip:mm/pkeys] pkeys: Add " tip-bot for Dave Hansen 2016-07-29 16:30 ` [PATCH 08/10] x86, pkeys: default to a restrictive init PKRU Dave Hansen 2016-07-29 16:30 ` Dave Hansen 2016-07-29 17:29 ` Andy Lutomirski 2016-07-29 17:29 ` Andy Lutomirski 2016-07-29 17:50 ` Dave Hansen 2016-07-29 17:50 ` Dave Hansen 2016-07-29 19:44 ` Andy Lutomirski 2016-07-29 19:44 ` Andy Lutomirski 2016-08-01 14:42 ` Vlastimil Babka 2016-08-01 14:42 ` Vlastimil Babka 2016-08-01 14:58 ` Dave Hansen 2016-08-01 14:58 ` Dave Hansen 2016-08-02 8:20 ` Vlastimil Babka 2016-08-02 8:20 ` Vlastimil Babka 2016-09-09 11:13 ` [tip:mm/pkeys] x86/pkeys: Default " tip-bot for Dave Hansen 2016-07-29 16:30 ` [PATCH 09/10] x86, pkeys: allow configuration of init_pkru Dave Hansen 2016-07-29 16:30 ` Dave Hansen 2016-08-02 8:28 ` Vlastimil Babka 2016-08-02 8:28 ` Vlastimil Babka 2016-08-02 14:37 ` Dave Hansen 2016-08-02 14:37 ` Dave Hansen 2016-09-09 11:14 ` [tip:mm/pkeys] x86/pkeys: Allow " tip-bot for Dave Hansen 2016-07-29 16:30 ` [PATCH 10/10] x86, pkeys: add self-tests Dave Hansen 2016-07-29 16:30 ` Dave Hansen 2016-09-09 11:14 ` [tip:mm/pkeys] x86/pkeys: Add self-tests tip-bot for Dave Hansen 2016-08-08 23:18 [PATCH 00/10] [v6] System Calls for Memory Protection Keys Dave Hansen 2016-08-08 23:18 ` [PATCH 01/10] x86, pkeys: add fault handling for PF_PK page fault bit Dave Hansen 2016-08-08 23:18 ` Dave Hansen
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