From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 741BCC3DA6E for ; Fri, 5 Jan 2024 13:15:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=rP3iDaznzIfm4O9sJIS7G/fHujwiFZ0fbF7KvWpuLZw=; b=qZakEn6RdziT6M rgYS7iu8H0+doVszRbW/zQrEqN6Xp+O/XfeYr3nDu/Lp/UmeKA1hUyALzIbwyQUPZ/v0/xNCzOqFv UvF3xG3CteQIhgbsmw4rbwt4/eMbUHSlxBcab6k89vyZULjNAxaNFHaVpHZEKZiP3V7Avirh3mc7k JLkn2UM4HPHzq5Q7+Ej3MXFBAPBYUTTZg6U1Vp2ct/LGMtx4AxWCYy7P2eN4ZY+nf4kHJO8dixmHb HJzp+CLFZ0/QjZD1atZa3w9BjuAtdacNEPbcAPZU1z5ERRQrxpcWpPzKi98HxWxiC8eIHSanL0xdV YUMkziOA5m2LqGtBuiVw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rLk2A-00GwcN-34; Fri, 05 Jan 2024 13:14:46 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rLk27-00GwZv-0B for linux-arm-kernel@lists.infradead.org; Fri, 05 Jan 2024 13:14:45 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 20F23C15; Fri, 5 Jan 2024 05:15:24 -0800 (PST) Received: from FVFF77S0Q05N (unknown [10.57.86.44]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 30D123F64C; Fri, 5 Jan 2024 05:14:36 -0800 (PST) Date: Fri, 5 Jan 2024 13:14:30 +0000 From: Mark Rutland To: Leonardo Bras Cc: Oleg Nesterov , Catalin Marinas , Will Deacon , Mark Brown , "Steven Rostedt (Google)" , Arnd Bergmann , Guo Hui , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 1/1] arm64: remove unnecessary ifdefs around is_compat_task() Message-ID: References: <20240105041458.126602-3-leobras@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240105041458.126602-3-leobras@redhat.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240105_051443_192711_DB4F49E6 X-CRM114-Status: GOOD ( 29.53 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Jan 05, 2024 at 01:15:00AM -0300, Leonardo Bras wrote: > Currently some parts of the codebase will test for CONFIG_COMPAT before > testing is_compat_task(). > > is_compat_task() is a inlined function only present on CONFIG_COMPAT. > On the other hand, for !CONFIG_COMPAT, we have in linux/compat.h: > > #define is_compat_task() (0) > > Since we have this define available in every usage of is_compat_task() for > !CONFIG_COMPAT, it's unnecessary to keep the ifdefs, since the compiler is > smart enough to optimize-out those snippets on CONFIG_COMPAT=n > > Signed-off-by: Leonardo Bras I tried this atop the arm64 for-next/core branch, using GCC 13.2.0; building defconfig + CONFIG_COMPAT=n results in build errors: [mark@lakrids:~/src/linux]% usekorg 13.2.0 make ARCH=arm64 CROSS_COMPILE=aarch64-linux- Image CALL scripts/checksyscalls.sh CC arch/arm64/kernel/ptrace.o arch/arm64/kernel/ptrace.c: In function 'task_user_regset_view': arch/arm64/kernel/ptrace.c:2121:25: error: 'user_aarch32_view' undeclared (first use in this function); did you mean 'user_aarch64_view'? 2121 | return &user_aarch32_view; | ^~~~~~~~~~~~~~~~~ | user_aarch64_view arch/arm64/kernel/ptrace.c:2121:25: note: each undeclared identifier is reported only once for each function it appears in arch/arm64/kernel/ptrace.c:2123:25: error: 'user_aarch32_ptrace_view' undeclared (first use in this function) 2123 | return &user_aarch32_ptrace_view; | ^~~~~~~~~~~~~~~~~~~~~~~~ make[4]: *** [scripts/Makefile.build:243: arch/arm64/kernel/ptrace.o] Error 1 make[3]: *** [scripts/Makefile.build:480: arch/arm64/kernel] Error 2 make[2]: *** [scripts/Makefile.build:480: arch/arm64] Error 2 make[1]: *** [/home/mark/src/linux/Makefile:1911: .] Error 2 make: *** [Makefile:234: __sub-make] Error 2 ... and looking at the code, user_aarch32_view and user_aarch32_ptrace_view are both defined under ifdeffery for CONFIG_COMPAT, so that's obviously not going to work... That aside, removing ifdeffery is generally nice, so could you please try building with CONFIG_COMPAT=n and see where you get to? Thanks, Mark. > --- > Changes since RFCv1: > - Removed unnecessary new inlined is_compat_task() for arm64 > - Adjusted commit text and title > Link: https://lore.kernel.org/all/20240104192433.109983-2-leobras@redhat.com/ > > arch/arm64/kernel/ptrace.c | 6 ++---- > arch/arm64/kernel/syscall.c | 5 +---- > 2 files changed, 3 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c > index 20d7ef82de90a..9f8781f1fdfda 100644 > --- a/arch/arm64/kernel/ptrace.c > +++ b/arch/arm64/kernel/ptrace.c > @@ -173,7 +173,6 @@ static void ptrace_hbptriggered(struct perf_event *bp, > struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp); > const char *desc = "Hardware breakpoint trap (ptrace)"; > > -#ifdef CONFIG_COMPAT > if (is_compat_task()) { > int si_errno = 0; > int i; > @@ -195,7 +194,7 @@ static void ptrace_hbptriggered(struct perf_event *bp, > desc); > return; > } > -#endif > + > arm64_force_sig_fault(SIGTRAP, TRAP_HWBKPT, bkpt->trigger, desc); > } > > @@ -2112,7 +2111,6 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, > > const struct user_regset_view *task_user_regset_view(struct task_struct *task) > { > -#ifdef CONFIG_COMPAT > /* > * Core dumping of 32-bit tasks or compat ptrace requests must use the > * user_aarch32_view compatible with arm32. Native ptrace requests on > @@ -2123,7 +2121,7 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task) > return &user_aarch32_view; > else if (is_compat_thread(task_thread_info(task))) > return &user_aarch32_ptrace_view; > -#endif > + > return &user_aarch64_view; > } > > diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c > index 9a70d9746b661..ad198262b9817 100644 > --- a/arch/arm64/kernel/syscall.c > +++ b/arch/arm64/kernel/syscall.c > @@ -20,14 +20,11 @@ long sys_ni_syscall(void); > > static long do_ni_syscall(struct pt_regs *regs, int scno) > { > -#ifdef CONFIG_COMPAT > - long ret; > if (is_compat_task()) { > - ret = compat_arm_syscall(regs, scno); > + long ret = compat_arm_syscall(regs, scno); > if (ret != -ENOSYS) > return ret; > } > -#endif > > return sys_ni_syscall(); > } > -- > 2.43.0 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel