From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x224VOqNFfVFQ8eGHWp4rI+9BZZ+dH3t7AvOU5wAmhAFSeOX00y/qCK+oUhgpzPQRwUthVv/a ARC-Seal: i=1; a=rsa-sha256; t=1517855057; cv=none; d=google.com; s=arc-20160816; b=NgsZG06rEWbN8XEzs1AaDqa/8SDl1C5FaefML4zE308rpEJEhQJX6FlY/KwCNgC79n U1Nkjb/9U9QO/4uL2v6wlqdLKPG6gXxNC5cw6BWLiFe5f1SvxDo/G84twtk/a7ExVMQs sA4vZYdAFk/fPNO5EHOLszVAHRahCi6Ldx2TYIthhv4XiursAfXit6R1Knu0W0NP4cr4 raTrqq441FdT+k2AXDAlH8VX+JfbzVle46mp84pM9RSzjAOWdRSAY/tbp5U4FRuBooJq AAjFfHzL1Ak7Au3wraEZqDOZgW4MhNxki+KYLdg5gDuYvWUA5ePkMiJ1W67PBUrrIbUE Wr4g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=t+ldpO8OvW/VkJ0TPkCxSogMPH8nsZqZlGLL4bslJWw=; b=HsEUPJG2nTbOqJi6Q69mHJAKuNZXMjh5H0/YSFoxV+PW87G2LMhRrKwRAGKTXB/k5k jTLgq+1vpCprgmzf8nYjgXr/k9E4hDiUrKPYpxvcw5lXfgfYBXKAUYm9pZk/e2Fi+dAF usRCIXKBCmQIYq8IkcO1DK+/p4n3hnFHqtypm+Hq0WVvTJjOPfFNVNNTisCkmCEoGOaj kRtR0Zsw72UaakgZOtZNBc7o1O/7+crEWlhD8EQJMe1fYYNlmAbHgx430qjrtBvZcEe0 8bwlHEPKg8IIDtIW7kXKfiC/V7MvKTInpYND0GlPlF47AcbtX/F2mndlPlS1P93syH/G T/0Q== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 104.132.1.108 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 104.132.1.108 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linus Torvalds , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Kernel Hardening Subject: [PATCH 4.14 35/64] x86/asm: Move status from thread_struct to thread_info Date: Mon, 5 Feb 2018 10:22:54 -0800 Message-Id: <20180205182140.021211346@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180205182138.571333346@linuxfoundation.org> References: <20180205182138.571333346@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1591586384640420219?= X-GMAIL-MSGID: =?utf-8?q?1591586384640420219?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Lutomirski luto@kernel.org commit 37a8f7c38339b22b69876d6f5a0ab851565284e3 The TS_COMPAT bit is very hot and is accessed from code paths that mostly also touch thread_info::flags. Move it into struct thread_info to improve cache locality. The only reason it was in thread_struct is that there was a brief period during which arch-specific fields were not allowed in struct thread_info. Linus suggested further changing: ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED); to: if (unlikely(ti->status & (TS_COMPAT|TS_I386_REGS_POKED))) ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED); on the theory that frequently dirtying the cacheline even in pure 64-bit code that never needs to modify status hurts performance. That could be a reasonable followup patch, but I suspect it matters less on top of this patch. Suggested-by: Linus Torvalds Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Reviewed-by: Ingo Molnar Acked-by: Linus Torvalds Cc: Borislav Petkov Cc: Kernel Hardening Link: https://lkml.kernel.org/r/03148bcc1b217100e6e8ecf6a5468c45cf4304b6.1517164461.git.luto@kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/x86/entry/common.c | 4 ++-- arch/x86/include/asm/processor.h | 2 -- arch/x86/include/asm/syscall.h | 6 +++--- arch/x86/include/asm/thread_info.h | 3 ++- arch/x86/kernel/process_64.c | 4 ++-- arch/x86/kernel/ptrace.c | 2 +- arch/x86/kernel/signal.c | 2 +- 7 files changed, 11 insertions(+), 12 deletions(-) --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -208,7 +208,7 @@ __visible inline void prepare_exit_to_us * special case only applies after poking regs and before the * very next return to user mode. */ - current->thread.status &= ~(TS_COMPAT|TS_I386_REGS_POKED); + ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED); #endif user_enter_irqoff(); @@ -306,7 +306,7 @@ static __always_inline void do_syscall_3 unsigned int nr = (unsigned int)regs->orig_ax; #ifdef CONFIG_IA32_EMULATION - current->thread.status |= TS_COMPAT; + ti->status |= TS_COMPAT; #endif if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY) { --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -459,8 +459,6 @@ struct thread_struct { unsigned short gsindex; #endif - u32 status; /* thread synchronous flags */ - #ifdef CONFIG_X86_64 unsigned long fsbase; unsigned long gsbase; --- a/arch/x86/include/asm/syscall.h +++ b/arch/x86/include/asm/syscall.h @@ -60,7 +60,7 @@ static inline long syscall_get_error(str * TS_COMPAT is set for 32-bit syscall entries and then * remains set until we return to user mode. */ - if (task->thread.status & (TS_COMPAT|TS_I386_REGS_POKED)) + if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED)) /* * Sign-extend the value so (int)-EFOO becomes (long)-EFOO * and will match correctly in comparisons. @@ -116,7 +116,7 @@ static inline void syscall_get_arguments unsigned long *args) { # ifdef CONFIG_IA32_EMULATION - if (task->thread.status & TS_COMPAT) + if (task->thread_info.status & TS_COMPAT) switch (i) { case 0: if (!n--) break; @@ -177,7 +177,7 @@ static inline void syscall_set_arguments const unsigned long *args) { # ifdef CONFIG_IA32_EMULATION - if (task->thread.status & TS_COMPAT) + if (task->thread_info.status & TS_COMPAT) switch (i) { case 0: if (!n--) break; --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -55,6 +55,7 @@ struct task_struct; struct thread_info { unsigned long flags; /* low level flags */ + u32 status; /* thread synchronous flags */ }; #define INIT_THREAD_INFO(tsk) \ @@ -221,7 +222,7 @@ static inline int arch_within_stack_fram #define in_ia32_syscall() true #else #define in_ia32_syscall() (IS_ENABLED(CONFIG_IA32_EMULATION) && \ - current->thread.status & TS_COMPAT) + current_thread_info()->status & TS_COMPAT) #endif /* --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -557,7 +557,7 @@ static void __set_personality_x32(void) * Pretend to come from a x32 execve. */ task_pt_regs(current)->orig_ax = __NR_x32_execve | __X32_SYSCALL_BIT; - current->thread.status &= ~TS_COMPAT; + current_thread_info()->status &= ~TS_COMPAT; #endif } @@ -571,7 +571,7 @@ static void __set_personality_ia32(void) current->personality |= force_personality32; /* Prepare the first "return" to user space */ task_pt_regs(current)->orig_ax = __NR_ia32_execve; - current->thread.status |= TS_COMPAT; + current_thread_info()->status |= TS_COMPAT; #endif } --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -935,7 +935,7 @@ static int putreg32(struct task_struct * */ regs->orig_ax = value; if (syscall_get_nr(child, regs) >= 0) - child->thread.status |= TS_I386_REGS_POKED; + child->thread_info.status |= TS_I386_REGS_POKED; break; case offsetof(struct user32, regs.eflags): --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -787,7 +787,7 @@ static inline unsigned long get_nr_resta * than the tracee. */ #ifdef CONFIG_IA32_EMULATION - if (current->thread.status & (TS_COMPAT|TS_I386_REGS_POKED)) + if (current_thread_info()->status & (TS_COMPAT|TS_I386_REGS_POKED)) return __NR_ia32_restart_syscall; #endif #ifdef CONFIG_X86_X32_ABI