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[209.132.180.131]) by mx.google.com with ESMTPS id ks1si26028941pbc.41.2015.08.31.14.12.15 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 31 Aug 2015 14:12:16 -0700 (PDT) Received-SPF: pass (google.com: domain of libc-alpha-return-62844-patch=linaro.org@sourceware.org designates 209.132.180.131 as permitted sender) client-ip=209.132.180.131; Received: (qmail 56075 invoked by alias); 31 Aug 2015 21:11:48 -0000 Mailing-List: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org Precedence: list 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 55985 invoked by uid 89); 31 Aug 2015 21:11:47 -0000 X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_LOW, SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail-qk0-f179.google.com X-Received: by 10.13.223.201 with SMTP id i192mr7768877ywe.7.1441055491094; Mon, 31 Aug 2015 14:11:31 -0700 (PDT) From: Adhemerval Zanella Subject: [PATCH 08/08] nptl: arm: Fix Race conditions in pthread cancellation (BZ#12683) To: GNU C Library Message-ID: <55E4C300.9080800@linaro.org> Date: Mon, 31 Aug 2015 18:11:28 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 X-Original-Sender: adhemerval.zanella@linaro.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 2a00:1450:4010:c04::230 as permitted sender) smtp.mailfrom=patch+caf_=patchwork-forward=linaro.org@linaro.org; dkim=pass header.i=@sourceware.org X-Google-Group-Id: 836684582541 This patch adds the ARM modifications required for the BZ#12683 fix. It basically removes the enable_asynccancel/disable_asynccancel function usage on code, provide a arch-specific symbol that contains global markers to be used in SIGCANCEL handler. --- * sysdeps/unix/sysv/linux/arm/syscall_cancel.S: New file. * sysdeps/unix/sysv/linux/arm/sysdep-cancel.h (PSEUDO): Redefine to call __syscall_cancel function for cancellable syscalls. * sysdeps/unix/sysv/linux/arm/sysdep.h (SYSCALL_CANCEL_ERROR): Add definition. (SYSCALL_CANCEL_ERRNO): Likewise. -- diff --git a/sysdeps/unix/sysv/linux/arm/syscall_cancel.S b/sysdeps/unix/sysv/linux/arm/syscall_cancel.S new file mode 100644 index 0000000..dc56de1 --- /dev/null +++ b/sysdeps/unix/sysv/linux/arm/syscall_cancel.S @@ -0,0 +1,69 @@ +/* Cancellable syscall wrapper - aarch64 version. + Copyright (C) 2015 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 + +/* long int [r0] __syscall_cancel_arch (int *cancelhandling [r0], + long int nr [r1], + long int arg1 [r2], + long int arg2 [r3], + long int arg3 [SP], + long int arg4 [SP+4], + long int arg5 [SP+8], + long int arg6 [SP+12]) */ + + .thumb + .syntax unified + +ENTRY (__syscall_cancel_arch) + .fnstart + mov ip,sp + stmfd sp!,{r4,r5,r6,r7,lr} + .save {r4,r5,r6,r7,lr} + + cfi_adjust_cfa_offset (20) + cfi_rel_offset (lr, 16) + + .globl __syscall_cancel_arch_start +__syscall_cancel_arch_start: + + /* if (*cancelhandling & CANCELED_BITMASK) + __syscall_do_cancel() */ + ldr r0,[r0] + tst r0, #4 + bne 1f + + /* Issue a 6 argument syscall, the nr [r1] being the syscall + number. */ + mov r7,r1 + mov r0,r2 + mov r1,r3 + ldmfd ip,{r2,r3,r4,r5,r6} + svc 0x0 + + .globl __syscall_cancel_arch_end +__syscall_cancel_arch_end: + ldmfd sp!,{r4,r5,r6,r7,lr} + cfi_adjust_cfa_offset (-16); + bx lr + +1: + bl __syscall_do_cancel + .fnend +END (__syscall_cancel_arch) +libc_hidden_def (__syscall_cancel_arch) diff --git a/sysdeps/unix/sysv/linux/arm/sysdep-cancel.h b/sysdeps/unix/sysv/linux/arm/sysdep-cancel.h index bdefa80..9f03bb5 100644 --- a/sysdeps/unix/sysv/linux/arm/sysdep-cancel.h +++ b/sysdeps/unix/sysv/linux/arm/sysdep-cancel.h @@ -19,10 +19,17 @@ #include #ifndef __ASSEMBLER__ # include +# include #endif #if IS_IN (libc) || IS_IN (libpthread) || IS_IN (librt) +# if IS_IN (libc) +# define JMP_SYSCALL_CANCEL HIDDEN_JUMPTARGET(__syscall_cancel) +# else +# define JMP_SYSCALL_CANCEL __syscall_cancel(PLT) +# endif + /* NOTE: We do mark syscalls with unwind annotations, for the benefit of cancellation; but they're really only accurate at the point of the syscall. The ARM unwind directives are not rich enough without adding @@ -31,16 +38,10 @@ # undef PSEUDO # define PSEUDO(name, syscall_name, args) \ .text; \ - ENTRY (__##syscall_name##_nocancel); \ - CFI_SECTIONS; \ - DO_CALL (syscall_name, args); \ - cmn r0, $4096; \ - PSEUDO_RET; \ - END (__##syscall_name##_nocancel); \ ENTRY (name); \ SINGLE_THREAD_P; \ - DOARGS_##args; \ bne .Lpseudo_cancel; \ + DOARGS_##args; \ cfi_remember_state; \ ldr r7, =SYS_ify (syscall_name); \ swi 0x0; \ @@ -50,20 +51,31 @@ cfi_restore_state; \ .Lpseudo_cancel: \ .fnstart; /* matched by the .fnend in UNDOARGS below. */ \ - DOCARGS_##args; /* save syscall args etc. around CENABLE. */ \ - CENABLE; \ - mov ip, r0; /* put mask in safe place. */ \ - UNDOCARGS_##args; /* restore syscall args. */ \ - ldr r7, =SYS_ify (syscall_name); \ - swi 0x0; /* do the call. */ \ - mov r7, r0; /* save syscall return value. */ \ - mov r0, ip; /* get mask back. */ \ - CDISABLE; \ - mov r0, r7; /* retrieve return value. */ \ - RESTORE_LR_##args; \ - UNDOARGS_##args; \ + push {r4, r5, lr}; \ + .save {r4, r5, lr}; \ + PSEUDO_CANCEL_BEFORE; \ + movw r0, SYS_ify (syscall_name); \ + PSEUDO_CANCEL_AFTER; \ + pop {r4, r5, pc}; \ + .fnend; \ cmn r0, $4096 +# define PSEUDO_CANCEL_BEFORE \ + .pad #20; \ + sub sp, sp, #20; \ + ldr r5, [sp, #32]; \ + ldr r4, [sp, #36]; \ + str r3, [sp]; \ + mov r3, r2; \ + str r5, [sp, #4]; \ + mov r2, r1; \ + str r4, [sp, #8]; \ + mov r1, r0 + +# define PSEUDO_CANCEL_AFTER \ + bl JMP_SYSCALL_CANCEL; \ + add sp, sp, #20 + /* DOARGS pushes eight bytes on the stack for five arguments, twelve bytes for six arguments, and four bytes for fewer. In order to preserve doubleword alignment, sometimes we must save an extra register. */ @@ -182,18 +194,9 @@ RESTORE_LR_0 # if IS_IN (libpthread) -# define CENABLE bl PLTJMP(__pthread_enable_asynccancel) -# define CDISABLE bl PLTJMP(__pthread_disable_asynccancel) # define __local_multiple_threads __pthread_multiple_threads # elif IS_IN (libc) -# define CENABLE bl PLTJMP(__libc_enable_asynccancel) -# define CDISABLE bl PLTJMP(__libc_disable_asynccancel) # define __local_multiple_threads __libc_multiple_threads -# elif IS_IN (librt) -# define CENABLE bl PLTJMP(__librt_enable_asynccancel) -# define CDISABLE bl PLTJMP(__librt_disable_asynccancel) -# else -# error Unsupported library # endif # if IS_IN (libpthread) || IS_IN (libc) @@ -238,4 +241,10 @@ extern int __local_multiple_threads attribute_hidden; # define RTLD_SINGLE_THREAD_P \ __builtin_expect (THREAD_GETMEM (THREAD_SELF, \ header.multiple_threads) == 0, 1) + +static inline +long int __pthread_get_ip (const struct ucontext *uc) +{ + return uc->uc_mcontext.arm_pc; +} #endif diff --git a/sysdeps/unix/sysv/linux/arm/sysdep.h b/sysdeps/unix/sysv/linux/arm/sysdep.h index 200f77a..6b18e34 100644 --- a/sysdeps/unix/sysv/linux/arm/sysdep.h +++ b/sysdeps/unix/sysv/linux/arm/sysdep.h @@ -387,6 +387,14 @@ __local_syscall_error: \ #undef INTERNAL_SYSCALL_ERRNO #define INTERNAL_SYSCALL_ERRNO(val, err) (-(val)) +#undef SYSCALL_CANCEL_ERROR +#define SYSCALL_CANCEL_ERROR(__val) \ + ((unsigned int) (__val) >= 0xfffff001u) + +#undef SYSCALL_CANCEL_ERRNO +#define SYSCALL_CANCEL_ERRNO(__val) \ + (-(__val)) + /* List of system calls which are supported as vsyscalls. */ #define HAVE_CLOCK_GETTIME_VSYSCALL 1 #define HAVE_GETTIMEOFDAY_VSYSCALL 1