From patchwork Sun Jun 26 21:55:41 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Lutomirski X-Patchwork-Id: 9199665 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8E56860752 for ; Sun, 26 Jun 2016 21:58:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7EACC28521 for ; Sun, 26 Jun 2016 21:58:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 726452855C; Sun, 26 Jun 2016 21:58:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 7D8BA28521 for ; Sun, 26 Jun 2016 21:58:00 +0000 (UTC) Received: (qmail 32565 invoked by uid 550); 26 Jun 2016 21:56:30 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: kernel-hardening@lists.openwall.com Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 32420 invoked from network); 26 Jun 2016 21:56:26 -0000 From: Andy Lutomirski To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Borislav Petkov , Nadav Amit , Kees Cook , Brian Gerst , "kernel-hardening@lists.openwall.com" , Linus Torvalds , Josh Poimboeuf , Jann Horn , Heiko Carstens , Andy Lutomirski , Richard Henderson , Ivan Kokshaysky , Matt Turner , Tony Luck , Fenghua Yu , Michal Simek , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Yoshinori Sato , Rich Felker , "David S. Miller" , Chris Metcalf , Peter Zijlstra , Borislav Petkov , Dmitry Safonov , Andrew Morton , linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org Date: Sun, 26 Jun 2016 14:55:41 -0700 Message-Id: X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: X-Virus-Scanned: ClamAV using ClamSMTP Subject: [kernel-hardening] [PATCH v4 19/29] signal: Consolidate {TS, TLF}_RESTORE_SIGMASK code X-Virus-Scanned: ClamAV using ClamSMTP In general, there's no need for the "restore sigmask" flag to live in ti->flags. alpha, ia64, microblaze, powerpc, sh, sparc (64-bit only), tile, and x86 use essentially identical alternative implementations, placing the flag in ti->status. Replace those optimized implementations with an equally good common implementation that stores it in a bitfield in struct task_struct and drop the custom implementations. Additional architectures can opt in by removing their TIF_RESTORE_SIGMASK defines. Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Tony Luck Cc: Fenghua Yu Cc: Michal Simek Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Yoshinori Sato Cc: Rich Felker Cc: "David S. Miller" Cc: Chris Metcalf Cc: x86@kernel.org Cc: Peter Zijlstra Cc: Borislav Petkov Cc: Brian Gerst Cc: Dmitry Safonov Cc: Andrew Morton Cc: linux-alpha@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-sh@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-arch@vger.kernel.org Signed-off-by: Andy Lutomirski --- arch/alpha/include/asm/thread_info.h | 27 ------------- arch/ia64/include/asm/thread_info.h | 28 -------------- arch/microblaze/include/asm/thread_info.h | 27 ------------- arch/powerpc/include/asm/thread_info.h | 25 ------------ arch/sh/include/asm/thread_info.h | 26 ------------- arch/sparc/include/asm/thread_info_64.h | 24 ------------ arch/tile/include/asm/thread_info.h | 27 ------------- arch/x86/include/asm/thread_info.h | 24 ------------ include/linux/sched.h | 63 +++++++++++++++++++++++++++++++ include/linux/thread_info.h | 41 -------------------- 10 files changed, 63 insertions(+), 249 deletions(-) diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h index 32e920a83ae5..e9e90bfa2b50 100644 --- a/arch/alpha/include/asm/thread_info.h +++ b/arch/alpha/include/asm/thread_info.h @@ -86,33 +86,6 @@ register struct thread_info *__current_thread_info __asm__("$8"); #define TS_UAC_NOPRINT 0x0001 /* ! Preserve the following three */ #define TS_UAC_NOFIX 0x0002 /* ! flags as they match */ #define TS_UAC_SIGBUS 0x0004 /* ! userspace part of 'osf_sysinfo' */ -#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */ - -#ifndef __ASSEMBLY__ -#define HAVE_SET_RESTORE_SIGMASK 1 -static inline void set_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - ti->status |= TS_RESTORE_SIGMASK; - WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags)); -} -static inline void clear_restore_sigmask(void) -{ - current_thread_info()->status &= ~TS_RESTORE_SIGMASK; -} -static inline bool test_restore_sigmask(void) -{ - return current_thread_info()->status & TS_RESTORE_SIGMASK; -} -static inline bool test_and_clear_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - if (!(ti->status & TS_RESTORE_SIGMASK)) - return false; - ti->status &= ~TS_RESTORE_SIGMASK; - return true; -} -#endif #define SET_UNALIGN_CTL(task,value) ({ \ __u32 status = task_thread_info(task)->status & ~UAC_BITMASK; \ diff --git a/arch/ia64/include/asm/thread_info.h b/arch/ia64/include/asm/thread_info.h index f0a72e98e5a4..c7026429816b 100644 --- a/arch/ia64/include/asm/thread_info.h +++ b/arch/ia64/include/asm/thread_info.h @@ -121,32 +121,4 @@ struct thread_info { /* like TIF_ALLWORK_BITS but sans TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT */ #define TIF_WORK_MASK (TIF_ALLWORK_MASK&~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)) -#define TS_RESTORE_SIGMASK 2 /* restore signal mask in do_signal() */ - -#ifndef __ASSEMBLY__ -#define HAVE_SET_RESTORE_SIGMASK 1 -static inline void set_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - ti->status |= TS_RESTORE_SIGMASK; - WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags)); -} -static inline void clear_restore_sigmask(void) -{ - current_thread_info()->status &= ~TS_RESTORE_SIGMASK; -} -static inline bool test_restore_sigmask(void) -{ - return current_thread_info()->status & TS_RESTORE_SIGMASK; -} -static inline bool test_and_clear_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - if (!(ti->status & TS_RESTORE_SIGMASK)) - return false; - ti->status &= ~TS_RESTORE_SIGMASK; - return true; -} -#endif /* !__ASSEMBLY__ */ - #endif /* _ASM_IA64_THREAD_INFO_H */ diff --git a/arch/microblaze/include/asm/thread_info.h b/arch/microblaze/include/asm/thread_info.h index 383f387b4eee..e7e8954e9815 100644 --- a/arch/microblaze/include/asm/thread_info.h +++ b/arch/microblaze/include/asm/thread_info.h @@ -148,33 +148,6 @@ static inline struct thread_info *current_thread_info(void) */ /* FPU was used by this task this quantum (SMP) */ #define TS_USEDFPU 0x0001 -#define TS_RESTORE_SIGMASK 0x0002 - -#ifndef __ASSEMBLY__ -#define HAVE_SET_RESTORE_SIGMASK 1 -static inline void set_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - ti->status |= TS_RESTORE_SIGMASK; - WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags)); -} -static inline void clear_restore_sigmask(void) -{ - current_thread_info()->status &= ~TS_RESTORE_SIGMASK; -} -static inline bool test_restore_sigmask(void) -{ - return current_thread_info()->status & TS_RESTORE_SIGMASK; -} -static inline bool test_and_clear_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - if (!(ti->status & TS_RESTORE_SIGMASK)) - return false; - ti->status &= ~TS_RESTORE_SIGMASK; - return true; -} -#endif #endif /* __KERNEL__ */ #endif /* _ASM_MICROBLAZE_THREAD_INFO_H */ diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index 8febc3f66d53..cfc35195f95e 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -134,40 +134,15 @@ static inline struct thread_info *current_thread_info(void) /* Don't move TLF_NAPPING without adjusting the code in entry_32.S */ #define TLF_NAPPING 0 /* idle thread enabled NAP mode */ #define TLF_SLEEPING 1 /* suspend code enabled SLEEP mode */ -#define TLF_RESTORE_SIGMASK 2 /* Restore signal mask in do_signal */ #define TLF_LAZY_MMU 3 /* tlb_batch is active */ #define TLF_RUNLATCH 4 /* Is the runlatch enabled? */ #define _TLF_NAPPING (1 << TLF_NAPPING) #define _TLF_SLEEPING (1 << TLF_SLEEPING) -#define _TLF_RESTORE_SIGMASK (1 << TLF_RESTORE_SIGMASK) #define _TLF_LAZY_MMU (1 << TLF_LAZY_MMU) #define _TLF_RUNLATCH (1 << TLF_RUNLATCH) #ifndef __ASSEMBLY__ -#define HAVE_SET_RESTORE_SIGMASK 1 -static inline void set_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - ti->local_flags |= _TLF_RESTORE_SIGMASK; - WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags)); -} -static inline void clear_restore_sigmask(void) -{ - current_thread_info()->local_flags &= ~_TLF_RESTORE_SIGMASK; -} -static inline bool test_restore_sigmask(void) -{ - return current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK; -} -static inline bool test_and_clear_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - if (!(ti->local_flags & _TLF_RESTORE_SIGMASK)) - return false; - ti->local_flags &= ~_TLF_RESTORE_SIGMASK; - return true; -} static inline bool test_thread_local_flags(unsigned int flags) { diff --git a/arch/sh/include/asm/thread_info.h b/arch/sh/include/asm/thread_info.h index 2afa321157be..6c65dcd470ab 100644 --- a/arch/sh/include/asm/thread_info.h +++ b/arch/sh/include/asm/thread_info.h @@ -151,19 +151,10 @@ extern void init_thread_xstate(void); * ever touches our thread-synchronous status, so we don't * have to worry about atomic accesses. */ -#define TS_RESTORE_SIGMASK 0x0001 /* restore signal mask in do_signal() */ #define TS_USEDFPU 0x0002 /* FPU used by this task this quantum */ #ifndef __ASSEMBLY__ -#define HAVE_SET_RESTORE_SIGMASK 1 -static inline void set_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - ti->status |= TS_RESTORE_SIGMASK; - WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags)); -} - #define TI_FLAG_FAULT_CODE_SHIFT 24 /* @@ -182,23 +173,6 @@ static inline unsigned int get_thread_fault_code(void) return ti->flags >> TI_FLAG_FAULT_CODE_SHIFT; } -static inline void clear_restore_sigmask(void) -{ - current_thread_info()->status &= ~TS_RESTORE_SIGMASK; -} -static inline bool test_restore_sigmask(void) -{ - return current_thread_info()->status & TS_RESTORE_SIGMASK; -} -static inline bool test_and_clear_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - if (!(ti->status & TS_RESTORE_SIGMASK)) - return false; - ti->status &= ~TS_RESTORE_SIGMASK; - return true; -} - #endif /* !__ASSEMBLY__ */ #endif /* __KERNEL__ */ diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h index bde59825d06c..3d7b925f6516 100644 --- a/arch/sparc/include/asm/thread_info_64.h +++ b/arch/sparc/include/asm/thread_info_64.h @@ -222,32 +222,8 @@ register struct thread_info *current_thread_info_reg asm("g6"); * * Note that there are only 8 bits available. */ -#define TS_RESTORE_SIGMASK 0x0001 /* restore signal mask in do_signal() */ #ifndef __ASSEMBLY__ -#define HAVE_SET_RESTORE_SIGMASK 1 -static inline void set_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - ti->status |= TS_RESTORE_SIGMASK; - WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags)); -} -static inline void clear_restore_sigmask(void) -{ - current_thread_info()->status &= ~TS_RESTORE_SIGMASK; -} -static inline bool test_restore_sigmask(void) -{ - return current_thread_info()->status & TS_RESTORE_SIGMASK; -} -static inline bool test_and_clear_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - if (!(ti->status & TS_RESTORE_SIGMASK)) - return false; - ti->status &= ~TS_RESTORE_SIGMASK; - return true; -} #define thread32_stack_is_64bit(__SP) (((__SP) & 0x1) != 0) #define test_thread_64bit_stack(__SP) \ diff --git a/arch/tile/include/asm/thread_info.h b/arch/tile/include/asm/thread_info.h index c1467ac59ce6..b7659b8f1117 100644 --- a/arch/tile/include/asm/thread_info.h +++ b/arch/tile/include/asm/thread_info.h @@ -166,32 +166,5 @@ extern void _cpu_idle(void); #ifdef __tilegx__ #define TS_COMPAT 0x0001 /* 32-bit compatibility mode */ #endif -#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal */ - -#ifndef __ASSEMBLY__ -#define HAVE_SET_RESTORE_SIGMASK 1 -static inline void set_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - ti->status |= TS_RESTORE_SIGMASK; - WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags)); -} -static inline void clear_restore_sigmask(void) -{ - current_thread_info()->status &= ~TS_RESTORE_SIGMASK; -} -static inline bool test_restore_sigmask(void) -{ - return current_thread_info()->status & TS_RESTORE_SIGMASK; -} -static inline bool test_and_clear_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - if (!(ti->status & TS_RESTORE_SIGMASK)) - return false; - ti->status &= ~TS_RESTORE_SIGMASK; - return true; -} -#endif /* !__ASSEMBLY__ */ #endif /* _ASM_TILE_THREAD_INFO_H */ diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index 89bff044a6f5..b45ffdda3549 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -219,32 +219,8 @@ static inline unsigned long current_stack_pointer(void) * have to worry about atomic accesses. */ #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ -#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */ #ifndef __ASSEMBLY__ -#define HAVE_SET_RESTORE_SIGMASK 1 -static inline void set_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - ti->status |= TS_RESTORE_SIGMASK; - WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags)); -} -static inline void clear_restore_sigmask(void) -{ - current_thread_info()->status &= ~TS_RESTORE_SIGMASK; -} -static inline bool test_restore_sigmask(void) -{ - return current_thread_info()->status & TS_RESTORE_SIGMASK; -} -static inline bool test_and_clear_restore_sigmask(void) -{ - struct thread_info *ti = current_thread_info(); - if (!(ti->status & TS_RESTORE_SIGMASK)) - return false; - ti->status &= ~TS_RESTORE_SIGMASK; - return true; -} static inline bool in_ia32_syscall(void) { diff --git a/include/linux/sched.h b/include/linux/sched.h index 26869dba21f1..569df670407a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1545,6 +1545,9 @@ struct task_struct { /* unserialized, strictly 'current' */ unsigned in_execve:1; /* bit to tell LSMs we're in execve */ unsigned in_iowait:1; +#if !defined(TIF_RESTORE_SIGMASK) + unsigned restore_sigmask:1; +#endif #ifdef CONFIG_MEMCG unsigned memcg_may_oom:1; #ifndef CONFIG_SLOB @@ -2664,6 +2667,66 @@ extern void sigqueue_free(struct sigqueue *); extern int send_sigqueue(struct sigqueue *, struct task_struct *, int group); extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *); +#ifdef TIF_RESTORE_SIGMASK +/* + * Legacy restore_sigmask accessors. These are inefficient on + * SMP architectures because they require atomic operations. + */ + +/** + * set_restore_sigmask() - make sure saved_sigmask processing gets done + * + * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code + * will run before returning to user mode, to process the flag. For + * all callers, TIF_SIGPENDING is already set or it's no harm to set + * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the + * arch code will notice on return to user mode, in case those bits + * are scarce. We set TIF_SIGPENDING here to ensure that the arch + * signal code always gets run when TIF_RESTORE_SIGMASK is set. + */ +static inline void set_restore_sigmask(void) +{ + set_thread_flag(TIF_RESTORE_SIGMASK); + WARN_ON(!test_thread_flag(TIF_SIGPENDING)); +} +static inline void clear_restore_sigmask(void) +{ + clear_thread_flag(TIF_RESTORE_SIGMASK); +} +static inline bool test_restore_sigmask(void) +{ + return test_thread_flag(TIF_RESTORE_SIGMASK); +} +static inline bool test_and_clear_restore_sigmask(void) +{ + return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK); +} + +#else /* TIF_RESTORE_SIGMASK */ + +/* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */ +static inline void set_restore_sigmask(void) +{ + current->restore_sigmask = true; + WARN_ON(!test_thread_flag(TIF_SIGPENDING)); +} +static inline void clear_restore_sigmask(void) +{ + current->restore_sigmask = false; +} +static inline bool test_restore_sigmask(void) +{ + return current->restore_sigmask; +} +static inline bool test_and_clear_restore_sigmask(void) +{ + if (!current->restore_sigmask) + return false; + current->restore_sigmask = false; + return true; +} +#endif + static inline void restore_saved_sigmask(void) { if (test_and_clear_restore_sigmask()) diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index b4c2a485b28a..352b1542f5cc 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -105,47 +105,6 @@ static inline int test_ti_thread_flag(struct thread_info *ti, int flag) #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) -#if defined TIF_RESTORE_SIGMASK && !defined HAVE_SET_RESTORE_SIGMASK -/* - * An arch can define its own version of set_restore_sigmask() to get the - * job done however works, with or without TIF_RESTORE_SIGMASK. - */ -#define HAVE_SET_RESTORE_SIGMASK 1 - -/** - * set_restore_sigmask() - make sure saved_sigmask processing gets done - * - * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code - * will run before returning to user mode, to process the flag. For - * all callers, TIF_SIGPENDING is already set or it's no harm to set - * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the - * arch code will notice on return to user mode, in case those bits - * are scarce. We set TIF_SIGPENDING here to ensure that the arch - * signal code always gets run when TIF_RESTORE_SIGMASK is set. - */ -static inline void set_restore_sigmask(void) -{ - set_thread_flag(TIF_RESTORE_SIGMASK); - WARN_ON(!test_thread_flag(TIF_SIGPENDING)); -} -static inline void clear_restore_sigmask(void) -{ - clear_thread_flag(TIF_RESTORE_SIGMASK); -} -static inline bool test_restore_sigmask(void) -{ - return test_thread_flag(TIF_RESTORE_SIGMASK); -} -static inline bool test_and_clear_restore_sigmask(void) -{ - return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK); -} -#endif /* TIF_RESTORE_SIGMASK && !HAVE_SET_RESTORE_SIGMASK */ - -#ifndef HAVE_SET_RESTORE_SIGMASK -#error "no set_restore_sigmask() provided and default one won't work" -#endif - #endif /* __KERNEL__ */ #endif /* _LINUX_THREAD_INFO_H */