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[209.132.180.131]) by mx.google.com with ESMTPS id f2si4693078plk.150.2017.02.15.12.08.14 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 15 Feb 2017 12:08:15 -0800 (PST) Received-SPF: pass (google.com: domain of libc-alpha-return-77367-patch=linaro.org@sourceware.org designates 209.132.180.131 as permitted sender) client-ip=209.132.180.131; Authentication-Results: mx.google.com; dkim=pass header.i=@sourceware.org; spf=pass (google.com: domain of libc-alpha-return-77367-patch=linaro.org@sourceware.org designates 209.132.180.131 as permitted sender) smtp.mailfrom=libc-alpha-return-77367-patch=linaro.org@sourceware.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:subject:date:message-id; q=dns; s= default; b=JMTnlxhA3HpRM+JBcvQs0FMlS/Sykq8mrCm9njl2pyeMFYIDN3EdZ nogS12FC58rHZGPbkx70Z5jdalk15h2RAtOGFwzLmmLMNZN4G8g9rGExv8sXVmyk K0Wf9y71fh3hHJZKX0kOkJuLO6oP9iPcnrk2MT0n3Ngbkgho38ywvo= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:subject:date:message-id; s=default; bh=0SugROExr2FNsHFULJBWOBe9Dt4=; b=EF4PEGw5K2v6HPuc9ecSRX9v9OFV KoO/rmy670SO0vjMHvluvAYs5HGo95UY2FfQinnN3B60+6bYh5ZPeKGycVuz8Jf/ Ues1qkyUKEA1NvmCRJdks/bhbar3S11mVvSaEXC9NB3POwlkw1i8LURmPKvYRh78 81+L2U70vq5Q4O0= Received: (qmail 107972 invoked by alias); 15 Feb 2017 20:07:56 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 107947 invoked by uid 89); 15 Feb 2017 20:07:56 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.0 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_LOW, RCVD_IN_SORBS_SPAM, SPF_PASS autolearn=ham version=3.3.2 spammy=83, mrs X-HELO: mail-qk0-f175.google.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id; bh=Zzi/04uCnwcqGtK5PrKn/aPVPfA0NevsPUeVoFWyq/A=; b=ApBJxHzxgzUlSCiEjrNvhx7PEw3EFLG3uGZIlwSNhZW3flhkhCynSWOgEAkHV+6K2g sWdXNIc0MFkHm9NPUQWgwsVys6McN5LS3+Hzj9pC9HDpFIHPi+3Sz2NuzNEuHinlRLhr 9wxdffrsloOSPSfnMLmGShN0ghDAX9sWiAyhe1iLcO+IuifeP09bEbglLv1/+CUIXB2E Y0bTNZFh5OWNp6DtMDHXxdkKUHpmFGbkLWyiYMucIXfFKKmk8WfZuJOGwFfi6MV6ctrV 8qUxQdws4JDLkMUOwzLfCxxNDS0T8F4IyXd3LpG5eiDxPB1vtJeY+puQsrwfexq+r+mh cC7A== X-Gm-Message-State: AMke39mx2j5NpYrqV7EuE1FoZdcjzSj/DhfH1CwGh8cJlyrbbK+PaLDuC62bzDAkrRFg2YOj X-Received: by 10.55.114.132 with SMTP id n126mr34700880qkc.112.1487189264102; Wed, 15 Feb 2017 12:07:44 -0800 (PST) From: Adhemerval Zanella To: libc-alpha@sourceware.org Subject: [PATCH v3] aarch64: Add split-stack TCB field Date: Wed, 15 Feb 2017 18:07:37 -0200 Message-Id: <1487189257-4518-1-git-send-email-adhemerval.zanella@linaro.org> Changes from previous version [1] - Change the symbol exported by loader from a function to a data symbol (__libc_tcb_private_ss). This allows binaries to fail at loading time instead of runtime on older glibc. - Fixed struct pthread alignment on TLS_PRE_TCB_SIZE. -- This patch adds split-stack support pointer guard on glibc for aarch64. Different from other architectures (powerpc, s390) where the memory is placed on TCB, aarch64 one is placed bofore thread pointer initial position. It has an advantage over extending TCB because for aarch64 TLS variable placement take in consideration tcbhead_t size and by changing its value would require to also update the static linker (and it would also add incompatibility with glibc and older linkers). For aarch64 tcb direct access is fastest for thread local variable on all mode and related TLS access. It requires just a direct load with displacement of -8 (since thread pointer points to tcbhead_t). It also adds a loader symbol (__tcb_private_ss) to signal de existence of the split stack guard area. Checked on aarch64-linux-gnu. * sysdeps/aarch64/Makefile [$(subdir) = elf] (sysdeps-dl-routines): Add tcb-version. * sysdeps/aarch64/Versions [ld] (GLIBC_2.26): Add __libc_tcb_private_ss. * sysdeps/aarch64/nptl/tls.h (tcbprehead_t): New struct. (TLS_PRE_TCB_SIZE): Take tcbprehead_t in consideration. (TLS_DEFINE_INIT_TP): Likewise. (THREAD_SELF): Likewise. (DB_THREAD_SELF): Likewise. * sysdeps/aarch64/tcb-version.c: New file. * sysdeps/unix/sysv/linux/aarch64/ld.abilist (GLIBC_2.26): Add. (__libc_tcb_private_ss): Likewise. * sysdeps/aarch64/nptl/tcb-offsets.sym (PTHREAD_SIZEOF): Rename to PTHREAD_PRE_TCB_SIZE. * sysdeps/unix/sysv/linux/aarch64/sysdep-cancel.h [!IS_IN (libprthread) && !IS_IN (libc) (SINGLE_THREAD_P): Use PTHREAD_PRE_TCB_SIZE instead of PTHREAD_SIZEOF. --- ChangeLog | 20 ++++++++++++++++++++ sysdeps/aarch64/Makefile | 2 +- sysdeps/aarch64/Versions | 8 ++++++++ sysdeps/aarch64/nptl/tcb-offsets.sym | 2 +- sysdeps/aarch64/nptl/tls.h | 25 ++++++++++++++++++++----- sysdeps/aarch64/tcb-version.c | 23 +++++++++++++++++++++++ sysdeps/unix/sysv/linux/aarch64/ld.abilist | 2 ++ sysdeps/unix/sysv/linux/aarch64/sysdep-cancel.h | 2 +- 8 files changed, 76 insertions(+), 8 deletions(-) create mode 100644 sysdeps/aarch64/tcb-version.c -- 2.7.4 diff --git a/sysdeps/aarch64/Makefile b/sysdeps/aarch64/Makefile index 562c137..0155988 100644 --- a/sysdeps/aarch64/Makefile +++ b/sysdeps/aarch64/Makefile @@ -5,7 +5,7 @@ CFLAGS-backtrace.c += -funwind-tables endif ifeq ($(subdir),elf) -sysdep-dl-routines += tlsdesc dl-tlsdesc +sysdep-dl-routines += tlsdesc dl-tlsdesc tcb-version gen-as-const-headers += dl-link.sym endif diff --git a/sysdeps/aarch64/Versions b/sysdeps/aarch64/Versions index e1aa44f..da547a8 100644 --- a/sysdeps/aarch64/Versions +++ b/sysdeps/aarch64/Versions @@ -3,3 +3,11 @@ libc { _mcount; } } + +ld { + GLIBC_2.26 { + # Symbol used to version control the private GLIBC TCB split-stack + # field. + __libc_tcb_private_ss; + } +} diff --git a/sysdeps/aarch64/nptl/tcb-offsets.sym b/sysdeps/aarch64/nptl/tcb-offsets.sym index 238647d..6004379 100644 --- a/sysdeps/aarch64/nptl/tcb-offsets.sym +++ b/sysdeps/aarch64/nptl/tcb-offsets.sym @@ -3,4 +3,4 @@ PTHREAD_MULTIPLE_THREADS_OFFSET offsetof (struct pthread, header.multiple_threads) PTHREAD_TID_OFFSET offsetof (struct pthread, tid) -PTHREAD_SIZEOF sizeof (struct pthread) +PTHREAD_PRE_TCB_SIZE TLS_PRE_TCB_SIZE diff --git a/sysdeps/aarch64/nptl/tls.h b/sysdeps/aarch64/nptl/tls.h index 175df39..d7c8ea7 100644 --- a/sysdeps/aarch64/nptl/tls.h +++ b/sysdeps/aarch64/nptl/tls.h @@ -26,6 +26,7 @@ # include # include # include +# include #else /* __ASSEMBLER__ */ # include @@ -49,6 +50,12 @@ typedef struct void *private; } tcbhead_t; +typedef struct +{ + /* GCC split stack support. */ + void *__private_ss; +} tcbprehead_t; + /* This is the size of the initial TCB. */ # define TLS_INIT_TCB_SIZE sizeof (tcbhead_t) @@ -58,8 +65,14 @@ typedef struct /* This is the size of the TCB. */ # define TLS_TCB_SIZE sizeof (tcbhead_t) -/* This is the size we need before TCB. */ -# define TLS_PRE_TCB_SIZE sizeof (struct pthread) +/* This is the size we need before TCB. Check if there is room for + tcbprehead_t in struct pthread's final padding and if not add it on + required pre-tcb size. */ +# define TLS_PRE_TCB_SIZE \ + (sizeof (struct pthread) \ + + (PTHREAD_STRUCT_END_PADDING < sizeof (tcbprehead_t) \ + ? ALIGN_UP (sizeof (tcbprehead_t), __alignof__ (struct pthread)) \ + : 0)) /* Alignment requirements for the TCB. */ # define TLS_TCB_ALIGN __alignof__ (struct pthread) @@ -84,7 +97,8 @@ typedef struct ({ __asm __volatile ("msr tpidr_el0, %0" : : "r" (tcbp)); NULL; }) /* Value passed to 'clone' for initialization of the thread register. */ -# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1 +# define TLS_DEFINE_INIT_TP(tp, pd) \ + void *tp = (void*)((uintptr_t) (pd) + TLS_PRE_TCB_SIZE) /* Return the address of the dtv for the current thread. */ # define THREAD_DTV() \ @@ -92,11 +106,12 @@ typedef struct /* Return the thread descriptor for the current thread. */ # define THREAD_SELF \ - ((struct pthread *)__builtin_thread_pointer () - 1) + ((struct pthread *)((uintptr_t) __builtin_thread_pointer () \ + - TLS_PRE_TCB_SIZE)) /* Magic for libthread_db to know how to do THREAD_SELF. */ # define DB_THREAD_SELF \ - CONST_THREAD_AREA (64, sizeof (struct pthread)) + CONST_THREAD_AREA (64, TLS_PRE_TCB_SIZE) /* Access to data in the thread descriptor is easy. */ # define THREAD_GETMEM(descr, member) \ diff --git a/sysdeps/aarch64/tcb-version.c b/sysdeps/aarch64/tcb-version.c new file mode 100644 index 0000000..c94e5d3 --- /dev/null +++ b/sysdeps/aarch64/tcb-version.c @@ -0,0 +1,23 @@ +/* TCB field abi advertise symbols. + Copyright (C) 2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include + +/* Symbol used to version control the private GLIBC TCB split-stack + field. */ +long int attribute_relro __libc_tcb_private_ss; diff --git a/sysdeps/unix/sysv/linux/aarch64/ld.abilist b/sysdeps/unix/sysv/linux/aarch64/ld.abilist index ec7f617..645d02d 100644 --- a/sysdeps/unix/sysv/linux/aarch64/ld.abilist +++ b/sysdeps/unix/sysv/linux/aarch64/ld.abilist @@ -8,3 +8,5 @@ GLIBC_2.17 calloc F GLIBC_2.17 free F GLIBC_2.17 malloc F GLIBC_2.17 realloc F +GLIBC_2.26 GLIBC_2.26 A +GLIBC_2.26 __libc_tcb_private_ss D 0x8 diff --git a/sysdeps/unix/sysv/linux/aarch64/sysdep-cancel.h b/sysdeps/unix/sysv/linux/aarch64/sysdep-cancel.h index 4be2259..e4ac2ba 100644 --- a/sysdeps/unix/sysv/linux/aarch64/sysdep-cancel.h +++ b/sysdeps/unix/sysv/linux/aarch64/sysdep-cancel.h @@ -114,7 +114,7 @@ extern int __local_multiple_threads attribute_hidden; # else # define SINGLE_THREAD_P(R) \ mrs x##R, tpidr_el0; \ - sub x##R, x##R, PTHREAD_SIZEOF; \ + sub x##R, x##R, PTHREAD_PRE_TCB_SIZE; \ ldr w##R, [x##R, PTHREAD_MULTIPLE_THREADS_OFFSET] # endif # endif