From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pf1-f195.google.com ([209.85.210.195]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1h6TU1-0004wk-0J for kexec@lists.infradead.org; Wed, 20 Mar 2019 05:09:47 +0000 Received: by mail-pf1-f195.google.com with SMTP id 9so771747pfj.13 for ; Tue, 19 Mar 2019 22:09:44 -0700 (PDT) From: Bhupesh Sharma Subject: [PATCH v3 0/3] Append new variables to vmcoreinfo (PTRS_PER_PGD for arm64 and MAX_PHYSMEM_BITS for all archs) Date: Wed, 20 Mar 2019 10:39:31 +0530 Message-Id: <1553058574-18606-1-git-send-email-bhsharma@redhat.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: linux-kernel@vger.kernel.org Cc: Mark Rutland , Kazuhito Hagio , Michael Ellerman , bhsharma@redhat.com, x86@kernel.org, Will Deacon , linuxppc-dev@lists.ozlabs.org, kexec@lists.infradead.org, James Morse , linux-arm-kernel@lists.infradead.org, Benjamin Herrenschmidt , Boris Petkov , Thomas Gleixner , bhupesh.linux@gmail.com, Dave Anderson , Ingo Molnar , Paul Mackerras Changes since v2: ---------------- - v2 can be seen here: http://lists.infradead.org/pipermail/kexec/2019-March/022531.html - Protected 'MAX_PHYSMEM_BITS' vmcoreinfo variable under CONFIG_SPARSEMEM ifdef sections, as suggested by Kazu. - Updated vmcoreinfo documentation to add description about 'MAX_PHYSMEM_BITS' variable (via [PATCH 3/3]). Changes since v1: ---------------- - v1 was sent out as a single patch which can be seen here: http://lists.infradead.org/pipermail/kexec/2019-February/022411.html - v2 breaks the single patch into two independent patches: [PATCH 1/2] appends 'PTRS_PER_PGD' to vmcoreinfo for arm64 arch, whereas [PATCH 2/2] appends 'MAX_PHYSMEM_BITS' to vmcoreinfo in core kernel code (all archs) This patchset primarily fixes the regression reported in user-space utilities like 'makedumpfile' and 'crash-utility' on arm64 architecture with the availability of 52-bit address space feature in underlying kernel. These regressions have been reported both on CPUs which don't support ARMv8.2 extensions (i.e. LVA, LPA) and are running newer kernels and also on prototype platforms (like ARMv8 FVP simulator model) which support ARMv8.2 extensions and are running newer kernels. The reason for these regressions is that right now user-space tools have no direct access to these values (since these are not exported from the kernel) and hence need to rely on a best-guess method of determining value of 'PTRS_PER_PGD' and 'MAX_PHYSMEM_BITS' supported by underlying kernel. Exporting these values via vmcoreinfo will help user-land in such cases. In addition, as per suggestion from makedumpfile maintainer (Kazu), it makes more sense to append 'MAX_PHYSMEM_BITS' to vmcoreinfo in the core code itself rather than in arm64 arch-specific code, so that the user-space code for other archs can also benefit from this addition to the vmcoreinfo and use it as a standard way of determining 'SECTIONS_SHIFT' value in user-land. Cc: Mark Rutland Cc: James Morse Cc: Will Deacon Cc: Boris Petkov Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Michael Ellerman Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Dave Anderson Cc: Kazuhito Hagio Cc: x86@kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: kexec@lists.infradead.org Bhupesh Sharma (3): arm64, vmcoreinfo : Append 'PTRS_PER_PGD' to vmcoreinfo crash_core, vmcoreinfo: Append 'MAX_PHYSMEM_BITS' to vmcoreinfo Documentation/vmcoreinfo: Add documentation for 'MAX_PHYSMEM_BITS' Documentation/kdump/vmcoreinfo.txt | 5 +++++ arch/arm64/kernel/crash_core.c | 1 + kernel/crash_core.c | 1 + 3 files changed, 7 insertions(+) -- 2.7.4 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec