From patchwork Tue Aug 18 03:33:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Collingbourne X-Patchwork-Id: 11719781 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7C47616B1 for ; Tue, 18 Aug 2020 03:35:52 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 560242053B for ; Tue, 18 Aug 2020 03:35:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="zxbZ/Ibh"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="E5eLUZXK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 560242053B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:To:From:Subject:References:Mime-Version:Message-Id: In-Reply-To:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jv99J/s4SlRGgx35UN3ZLPFsVMRZNwTDHMWuHsUY2eg=; b=zxbZ/Ibhi4WQ/nYGX6vSX2qg7 aV23wENPeQue+Qm62tx3b/hr4KET2em3KEuowsAN8rDrQ/TMAScmzkKe1ke6fJ06i13tTVmnuyuC/ R4fHtu0jliicT4tBQlDcFX2G9KMBKgxxyKOqcUsdnCGCJyHfynMyxuQoz5NZyqzW2TEl4RgBp0Gso SkpeXtw6V5fPqsG2s/zn+UcHs1FT0Xu3l6+CfcOCjbL2ewbVc6R1HtWmin8sMu56aUrzTjhsOpbUn 0kgDMJULXF/XVH45hq09q2n5Agx+2S4jp7aId0sQjLCt8Dcnicj+4uc7byzvMSetRhlvPRv/FHkwb 3q2PXW+Zg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k7sOG-0002Ul-FJ; Tue, 18 Aug 2020 03:34:24 +0000 Received: from mail-qv1-xf49.google.com ([2607:f8b0:4864:20::f49]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k7sO7-0002Qt-U2 for linux-arm-kernel@lists.infradead.org; Tue, 18 Aug 2020 03:34:16 +0000 Received: by mail-qv1-xf49.google.com with SMTP id d1so12295280qvs.21 for ; Mon, 17 Aug 2020 20:34:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=oo0pTnrmudx+T/LZl7NKgvvgOx2ScFEDi+Ld6DsnEYA=; b=E5eLUZXKyZdZt5jZAeoIi5h5DON/gzFXveM5r/58ZtdTNUuZDKrrote/usrHwVrim1 OYIo2wDOqpk6qPNwMjWuxuI3oWu6k3/bsMGUb1OqOJ/bFEsO61t1lnTdsyvFrXyrRCjO 7dyZedvX0CTmvV3AlMAFCxb6ewv6ZTZUPZLkcP0gVsbMD84niwyheiNgZ0Hgk8IThVhi 7+bjpktzi3FHhOlVCblmOw6r1A9gGEhGtMWp/AXW18IuimKCf5zUmfqmMIdphvBn88RC x1L0+mfX6T77uy4/EHB6ojrE5wcYu3TCSCKTJrVEtQJZ9TFIKhrWCRlImW3L8Hd3eLQg 64Iw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=oo0pTnrmudx+T/LZl7NKgvvgOx2ScFEDi+Ld6DsnEYA=; b=jSnFwqPEd5kXSCxL50nEgjU/X7vICUAAOGQYke5Prmfg+bxfhy/9P3Biysj3aZZ+Rb yXVhWtmhEcUvCxQ0+ki4IcyKVQBRjL9puZPjf/IAdTDp/+4kb6mN8xw0aZyiK+m0HgV5 b9IG/ITlpJ9brcYP3h1zJNpZ6CD1EbjghT3FEePQXmcvb4ttSA2+8zUiXuNdDe/bJMYC PuYozuePN3jxf23k7ga6BIqBpf+/HvHvesFTGOghAl2zzW0Ty+OrSLkIGKucAk+hecv7 XVkkmAAPZ7D+svagO7zzPlYnTQr6PVu1pwSD5DNbBUuKV3DOkXjFkwdQQ8IIffybOzTV Rzmw== X-Gm-Message-State: AOAM533TEaNdAHizO0wuUGjvBzpp1DD3/QLf1pM2MLBtAdA5r/gmQrlH 2xXSaQ4KC81EE+MAJ2KExwQn7RM= X-Google-Smtp-Source: ABdhPJwhRbaVy+KijVusyRCHgYhWLEP0EPv8B3cwxnf1KrzAsJjfpA4cLEJBYmdYxx032wAIClhDk74= X-Received: by 2002:a05:6214:184b:: with SMTP id d11mr17407724qvy.21.1597721652412; Mon, 17 Aug 2020 20:34:12 -0700 (PDT) Date: Mon, 17 Aug 2020 20:33:48 -0700 In-Reply-To: Message-Id: <68bd2d6544fb17bbe2fb90862e28ec38e079549a.1597720138.git.pcc@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.28.0.220.ged08abb693-goog Subject: [PATCH v9 3/6] signal: clear non-uapi flag bits when passing/returning sa_flags From: Peter Collingbourne To: Catalin Marinas , Evgenii Stepanov , Kostya Serebryany , Vincenzo Frascino , Dave Martin , Will Deacon , Oleg Nesterov , "Eric W. Biederman" , "James E.J. Bottomley" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200817_233416_052198_19EFF651 X-CRM114-Status: GOOD ( 18.17 ) X-Spam-Score: -7.7 (-------) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-7.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [2607:f8b0:4864:20:0:0:0:f49 listed in] [list.dnswl.org] -7.5 USER_IN_DEF_DKIM_WL From: address is in the default DKIM white-list 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.0 DKIMWL_WL_MED DKIMwl.org - Medium sender X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-parisc@vger.kernel.org, Andrey Konovalov , Kevin Brodsky , David Spickett , Peter Collingbourne , Linux ARM , Richard Henderson Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org This allows userspace to detect missing support for flag bits and allows the kernel to use non-uapi bits internally, as we are already doing in arch/x86 for two flag bits. Now that this change is in place, we no longer need the code in arch/x86 that was hiding these bits from userspace, so remove it. Signed-off-by: Peter Collingbourne --- View this change in Gerrit: https://linux-review.googlesource.com/q/I35aab6f5be932505d90f3b3450c083b4db1eca86 arch/arm/include/asm/signal.h | 4 ++++ arch/parisc/include/asm/signal.h | 4 ++++ arch/x86/kernel/signal_compat.c | 7 ------- include/linux/signal_types.h | 12 ++++++++++++ kernel/signal.c | 10 ++++++++++ 5 files changed, 30 insertions(+), 7 deletions(-) diff --git a/arch/arm/include/asm/signal.h b/arch/arm/include/asm/signal.h index 65530a042009..d1070a783993 100644 --- a/arch/arm/include/asm/signal.h +++ b/arch/arm/include/asm/signal.h @@ -17,6 +17,10 @@ typedef struct { unsigned long sig[_NSIG_WORDS]; } sigset_t; +#define SA_UAPI_FLAGS \ + (SA_NOCLDSTOP | SA_NOCLDWAIT | SA_SIGINFO | SA_THIRTYTWO | \ + SA_RESTORER | SA_ONSTACK | SA_RESTART | SA_NODEFER | SA_RESETHAND) + #define __ARCH_HAS_SA_RESTORER #include diff --git a/arch/parisc/include/asm/signal.h b/arch/parisc/include/asm/signal.h index 715c96ba2ec8..ad06e14f6e8a 100644 --- a/arch/parisc/include/asm/signal.h +++ b/arch/parisc/include/asm/signal.h @@ -21,6 +21,10 @@ typedef struct { unsigned long sig[_NSIG_WORDS]; } sigset_t; +#define SA_UAPI_FLAGS \ + (SA_ONSTACK | SA_RESETHAND | SA_NOCLDSTOP | SA_SIGINFO | SA_NODEFER | \ + SA_RESTART | SA_NOCLDWAIT | _SA_SIGGFAULT) + #include #endif /* !__ASSEMBLY */ diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c index 9ccbf0576cd0..c599013ae8cb 100644 --- a/arch/x86/kernel/signal_compat.c +++ b/arch/x86/kernel/signal_compat.c @@ -165,16 +165,9 @@ void sigaction_compat_abi(struct k_sigaction *act, struct k_sigaction *oact) { signal_compat_build_tests(); - /* Don't leak in-kernel non-uapi flags to user-space */ - if (oact) - oact->sa.sa_flags &= ~(SA_IA32_ABI | SA_X32_ABI); - if (!act) return; - /* Don't let flags to be set from userspace */ - act->sa.sa_flags &= ~(SA_IA32_ABI | SA_X32_ABI); - if (in_ia32_syscall()) act->sa.sa_flags |= SA_IA32_ABI; if (in_x32_syscall()) diff --git a/include/linux/signal_types.h b/include/linux/signal_types.h index f8a90ae9c6ec..e792f29b5846 100644 --- a/include/linux/signal_types.h +++ b/include/linux/signal_types.h @@ -68,4 +68,16 @@ struct ksignal { int sig; }; +#ifndef SA_UAPI_FLAGS +#ifdef SA_RESTORER +#define SA_UAPI_FLAGS \ + (SA_NOCLDSTOP | SA_NOCLDWAIT | SA_SIGINFO | SA_ONSTACK | SA_RESTART | \ + SA_NODEFER | SA_RESETHAND | SA_RESTORER) +#else +#define SA_UAPI_FLAGS \ + (SA_NOCLDSTOP | SA_NOCLDWAIT | SA_SIGINFO | SA_ONSTACK | SA_RESTART | \ + SA_NODEFER | SA_RESETHAND) +#endif +#endif + #endif /* _LINUX_SIGNAL_TYPES_H */ diff --git a/kernel/signal.c b/kernel/signal.c index 42b67d2cea37..348b7981f1ff 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -3984,6 +3984,16 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) if (oact) *oact = *k; + /* + * Clear unknown flag bits in order to allow userspace to detect missing + * support for flag bits and to allow the kernel to use non-uapi bits + * internally. + */ + if (act) + act->sa.sa_flags &= SA_UAPI_FLAGS; + if (oact) + oact->sa.sa_flags &= SA_UAPI_FLAGS; + sigaction_compat_abi(act, oact); if (act) {