From patchwork Fri Apr 19 09:47:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 162527 Delivered-To: patch@linaro.org Received: by 2002:a02:c6d8:0:0:0:0:0 with SMTP id r24csp1808141jan; Fri, 19 Apr 2019 02:49:56 -0700 (PDT) X-Google-Smtp-Source: APXvYqxqLxCWGpX4hWy5juawAODGBoTN5k0hoOKgpRPUjC7e90IaAeuFctBE6DNssWSwZCnTDl3Z X-Received: by 2002:a63:6e01:: with SMTP id j1mr2991591pgc.442.1555667396872; Fri, 19 Apr 2019 02:49:56 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1555667396; cv=none; d=google.com; s=arc-20160816; b=WOY7eNQm1Vdh4UFuYw8c2puKc+2S+/XPYqfznAwhLWvor1julBjbTeB6sHezKkT3+X 06JE6lsUgQYXulSCoLyt/Ae3OAwVMYbvCi/pj0of2kEBOsceELRPXL22ex5/Ok3Jd2CX p3r4CAVTpgyFLO8/yuTsy8OGtNIFEBP4zIbwWfuyD+i8v/u7rWQkNYSvvVZp9cuQiCX+ vquyGMO3Du6fqjY9SS+bVdwhV0Dj9iF3gP78fN9573Z38CFkWI0HnhiIMJAXo/F9Ddmi yzbIl5rrMFshxd/ajPOtcmdhZb1ZEB5yUqxYUYEpfy9WSlZEzmBciJy98hCvW3DN5rEG 75dQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=errors-to:sender:content-transfer-encoding:mime-version:cc :list-subscribe:list-help:list-post:list-archive:list-unsubscribe :list-id:precedence:references:in-reply-to:message-id:date:subject :to:from:dkim-signature:dkim-filter:dkim-signature; bh=d6UNRJSog+xQ5AKfbDQnhbhElyNSL9yc5SJgUuuCyY0=; b=SrfL61weiLi34snsS0IbwaUuwm60Q9u2QNqba0MeNPr8kmbqWaSSTU9UDqrqpD6Vm4 o/J4aFuVCgXWe5VOVbXmYeXoyE/hkmI7Lb7fDE9DtDXidq33R3FENlQtypDVVyGUWMz0 TlZcW2vfSS7PUO7VjfKB2Z0gB+hDOHza24hwb8sg2tb+xPkFWY5xmEdJLJdV6rHwzkUH rpDPICzVnqWHVaplPPN7uNBDFShP8EV3E0UdyAQ1K3uVvuFdgl00erbuLMY/BahMGEum lT9QIZ98gpze/mWowUqPWvNCQToeRX5c7xSae8tppkJ4YSd/VOOilBOHmdUz35Y2HGWk hv8w== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@lists.infradead.org header.s=bombadil.20170209 header.b=PieOKTJr; dkim=neutral (body hash did not verify) header.i=@nifty.com header.s=dec2015msa header.b=2JQf30n2; spf=pass (google.com: best guess record for domain of linux-mtd-bounces+patch=linaro.org@lists.infradead.org designates 2607:7c80:54:e::133 as permitted sender) smtp.mailfrom="linux-mtd-bounces+patch=linaro.org@lists.infradead.org" Return-Path: Received: from bombadil.infradead.org (bombadil.infradead.org. [2607:7c80:54:e::133]) by mx.google.com with ESMTPS id b15si5192651pfb.231.2019.04.19.02.49.56 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 19 Apr 2019 02:49:56 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-mtd-bounces+patch=linaro.org@lists.infradead.org designates 2607:7c80:54:e::133 as permitted sender) client-ip=2607:7c80:54:e::133; Authentication-Results: mx.google.com; dkim=pass header.i=@lists.infradead.org header.s=bombadil.20170209 header.b=PieOKTJr; dkim=neutral (body hash did not verify) header.i=@nifty.com header.s=dec2015msa header.b=2JQf30n2; spf=pass (google.com: best guess record for domain of linux-mtd-bounces+patch=linaro.org@lists.infradead.org designates 2607:7c80:54:e::133 as permitted sender) smtp.mailfrom="linux-mtd-bounces+patch=linaro.org@lists.infradead.org" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; 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a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1555667296; bh=xEQiTaRJoMiIIoSSR5uW02FG6OV+z3ajZxuyDMzswK8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2JQf30n281jQB4d2J0PFa1uofVewZCgz9BKrQlNEnXrgFMBLbR2Zq1r6w+iBaLG45 t3nsjO2yy9K2rayA6kAG7W5QOZXT/QC/pn2nbYfF3OTOTfF8RmCuBd5yJ5z4STfAVR S50CNHJXKGoZKrDOh8HkCZk629LOHn6U1lbZhC7JMhAyR3/Tr/rg3GcrCj9JDWjHAO UiGSppMnUWU7gB7Bziv+abekGW5t79hjFO9/SOc6KfN1rVoLYaqIJni87B3Xd6Wk7W H2/rg3c+1nge1l4Y9lbsm/7RvW65UIRkVG9T0d8qJA6UMAluoWZAQ17RYMK74wx8Rp ffTOmV/uhafAw== X-Nifty-SrcIP: [153.142.97.92] From: Masahiro Yamada To: Andrew Morton , linux-arch Subject: [PATCH v2 01/11] ARM: prevent tracing IPI_CPU_BACKTRACE Date: Fri, 19 Apr 2019 18:47:44 +0900 Message-Id: <20190419094754.24667-2-yamada.masahiro@socionext.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190419094754.24667-1-yamada.masahiro@socionext.com> References: <20190419094754.24667-1-yamada.masahiro@socionext.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190419_024848_509807_B7C1C520 X-CRM114-Status: GOOD ( 13.81 ) X-Spam-Score: 1.0 (+) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (1.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [210.131.2.75 listed in list.dnswl.org] 1.0 SPF_SOFTFAIL SPF: sender does not match SPF record (softfail) -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 X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Christophe Leroy , linux-s390@vger.kernel.org, Arnd Bergmann , x86@kernel.org, Heiko Carstens , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, Masahiro Yamada , Ingo Molnar , linux-mtd@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-mtd" Errors-To: linux-mtd-bounces+patch=linaro.org@lists.infradead.org From: Arnd Bergmann When function tracing for IPIs is enabled, we get a warning for an overflow of the ipi_types array with the IPI_CPU_BACKTRACE type as triggered by raise_nmi(): arch/arm/kernel/smp.c: In function 'raise_nmi': arch/arm/kernel/smp.c:489:2: error: array subscript is above array bounds [-Werror=array-bounds] trace_ipi_raise(target, ipi_types[ipinr]); This is a correct warning as we actually overflow the array here. This patch raise_nmi() to call __smp_cross_call() instead of smp_cross_call(), to avoid calling into ftrace. For clarification, I'm also adding a two new code comments describing how this one is special. The warning appears to have shown up after patch e7273ff49acf ("ARM: 8488/1: Make IPI_CPU_BACKTRACE a "non-secure" SGI"), which changed the number assignment from '15' to '8', but as far as I can tell has existed since the IPI tracepoints were first introduced. If we decide to backport this patch to stable kernels, we probably need to backport e7273ff49acf as well. Fixes: e7273ff49acf ("ARM: 8488/1: Make IPI_CPU_BACKTRACE a "non-secure" SGI") Fixes: 365ec7b17327 ("ARM: add IPI tracepoints") # v3.17 Signed-off-by: Arnd Bergmann [yamada.masahiro@socionext.com: rebase on v5.0-rc1] Signed-off-by: Masahiro Yamada --- This is a long-standing issue, and Arnd posted this patch two years ago: http://lists.infradead.org/pipermail/linux-arm-kernel/2016-February/409393.html It is no longer applied, so I rebased it on top of the latest kernel. Changes in v2: None arch/arm/include/asm/hardirq.h | 1 + arch/arm/kernel/smp.c | 6 +++++- 2 files changed, 6 insertions(+), 1 deletion(-) -- 2.17.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ diff --git a/arch/arm/include/asm/hardirq.h b/arch/arm/include/asm/hardirq.h index cba23eaa6072..7a88f160b1fb 100644 --- a/arch/arm/include/asm/hardirq.h +++ b/arch/arm/include/asm/hardirq.h @@ -6,6 +6,7 @@ #include #include +/* number of IPIS _not_ including IPI_CPU_BACKTRACE */ #define NR_IPI 7 typedef struct { diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index facd4240ca02..c93fe0f256de 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -70,6 +70,10 @@ enum ipi_msg_type { IPI_CPU_STOP, IPI_IRQ_WORK, IPI_COMPLETION, + /* + * CPU_BACKTRACE is special and not included in NR_IPI + * or tracable with trace_ipi_* + */ IPI_CPU_BACKTRACE, /* * SGI8-15 can be reserved by secure firmware, and thus may @@ -797,7 +801,7 @@ core_initcall(register_cpufreq_notifier); static void raise_nmi(cpumask_t *mask) { - smp_cross_call(mask, IPI_CPU_BACKTRACE); + __smp_cross_call(mask, IPI_CPU_BACKTRACE); } void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)