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[209.85.220.65]) by mx.google.com with SMTPS id w77-v6sor3846307wrb.67.2018.05.14.01.29.21 for (Google Transport Security); Mon, 14 May 2018 01:29:21 -0700 (PDT) Date: Mon, 14 May 2018 10:29:18 +0200 From: Ingo Molnar Subject: Re: [PATCH 00/13] [v4] x86, pkeys: two protection keys bug fixes Message-ID: <20180514082918.GA21574@gmail.com> References: <20180509171336.76636D88@viggo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180509171336.76636D88@viggo.jf.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxram@us.ibm.com, tglx@linutronix.de, dave.hansen@intel.com, mpe@ellerman.id.au, akpm@linux-foundation.org, shuah@kernel.org, shakeelb@google.com * Dave Hansen wrote: > Hi x86 maintainers, > > This set has been seen quite a few changes and additions since the > last post. Details below. > > Changes from v3: > * Reordered patches following Ingo's recommendations: Introduce > failing selftests first, then the kernel code to fix the test > failure. > * Increase verbosity and accuracy of do_not_expect_pk_fault() > messages. > * Removed abort() use from tests. Crashing is not nice. > * Remove some dead debugging code, fixing dprint_in_signal. > * Fix deadlocks from using printf() and friends in signal > handlers. > > Changes from v2: > * Clarified commit message in patch 1/9 taking some feedback from > Shuah. > > Changes from v1: > * Added Fixes: and cc'd stable. No code changes. > > -- > > This fixes two bugs, and adds selftests to make sure they stay fixed: > > 1. pkey 0 was not usable via mprotect_pkey() because it had never > been explicitly allocated. > 2. mprotect(PROT_EXEC) memory could sometimes be left with the > implicit exec-only protection key assigned. > > I already posted #1 previously. I'm including them both here because > I don't think it's been picked up in case folks want to pull these > all in a single bundle. > > Dave Hansen (13): > x86/pkeys/selftests: give better unexpected fault error messages > x86/pkeys/selftests: Stop using assert() > x86/pkeys/selftests: remove dead debugging code, fix dprint_in_signal > x86/pkeys/selftests: avoid printf-in-signal deadlocks > x86/pkeys/selftests: Allow faults on unknown keys > x86/pkeys/selftests: Factor out "instruction page" > x86/pkeys/selftests: Add PROT_EXEC test > x86/pkeys/selftests: Fix pkey exhaustion test off-by-one > x86/pkeys: Override pkey when moving away from PROT_EXEC > x86/pkeys/selftests: Fix pointer math > x86/pkeys/selftests: Save off 'prot' for allocations > x86/pkeys/selftests: Add a test for pkey 0 > x86/pkeys: Do not special case protection key 0 > > arch/x86/include/asm/mmu_context.h | 2 +- > arch/x86/include/asm/pkeys.h | 18 +- > arch/x86/mm/pkeys.c | 21 +- > tools/testing/selftests/x86/pkey-helpers.h | 20 +- > tools/testing/selftests/x86/protection_keys.c | 187 +++++++++++++----- > 5 files changed, 173 insertions(+), 75 deletions(-) So this series is looking good to me in principle, but trying to build it I got warnings and errors - see the build log below. Note that this is on a box with "Ubuntu 18.04 LTS (Bionic Beaver)". Thanks, Ingo ================> gcc -m32 -o /home/mingo/tip/tools/testing/selftests/x86/protection_keys_32 -O2 -g -std=gnu99 -pthread -Wall -no-pie -DCAN_BUILD_32 -DCAN_BUILD_64 protection_keys.c -lrt -ldl -lm protection_keys.c:232:0: warning: "SEGV_BNDERR" redefined #define SEGV_BNDERR 3 /* failed address bound checks */ In file included from /usr/include/signal.h:58:0, from protection_keys.c:33: /usr/include/bits/siginfo-consts.h:117:0: note: this is the location of the previous definition # define SEGV_BNDERR SEGV_BNDERR protection_keys.c:233:0: warning: "SEGV_PKUERR" redefined #define SEGV_PKUERR 4 In file included from /usr/include/signal.h:58:0, from protection_keys.c:33: /usr/include/bits/siginfo-consts.h:119:0: note: this is the location of the previous definition # define SEGV_PKUERR SEGV_PKUERR protection_keys.c:387:5: error: conflicting types for a??pkey_geta?? u32 pkey_get(int pkey, unsigned long flags) ^~~~~~~~ In file included from /usr/include/bits/mman-linux.h:115:0, from /usr/include/bits/mman.h:45, from /usr/include/sys/mman.h:41, from protection_keys.c:37: /usr/include/bits/mman-shared.h:64:5: note: previous declaration of a??pkey_geta?? was here int pkey_get (int __key) __THROW; ^~~~~~~~ protection_keys.c:409:5: error: conflicting types for a??pkey_seta?? int pkey_set(int pkey, unsigned long rights, unsigned long flags) ^~~~~~~~ In file included from /usr/include/bits/mman-linux.h:115:0, from /usr/include/bits/mman.h:45, from /usr/include/sys/mman.h:41, from protection_keys.c:37: /usr/include/bits/mman-shared.h:60:5: note: previous declaration of a??pkey_seta?? was here int pkey_set (int __key, unsigned int __access_rights) __THROW; ^~~~~~~~ Makefile:67: recipe for target '/home/mingo/tip/tools/testing/selftests/x86/protection_keys_32' failed make: *** [/home/mingo/tip/tools/testing/selftests/x86/protection_keys_32] Error 1