From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pg1-f195.google.com ([209.85.215.195]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gZwQ3-0006im-GV for kexec@lists.infradead.org; Thu, 20 Dec 2018 11:23:13 +0000 Received: by mail-pg1-f195.google.com with SMTP id z10so740199pgp.7 for ; Thu, 20 Dec 2018 03:22:59 -0800 (PST) From: Bhupesh Sharma Subject: [PATCH v2 0/2] kexec-tools/arm64: Add support to read PHYS_OFFSET from kcore Date: Thu, 20 Dec 2018 16:52:50 +0530 Message-Id: <1545304972-32333-1-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: kexec@lists.infradead.org Cc: Vadim.Lomovtsev@cavium.com, yanjiang.jin@hxt-semitech.com, bhsharma@redhat.com, takahiro.akashi@linaro.org, horms@verge.net.au, bhupesh.linux@gmail.com Changes from v1: --------------- - Added the support for older kernels, where we determine the PHYS_OFFSET value from PT_LOAD segments inside 'kcore'. - Improved commit logs since v1. On certain arm64 platforms, it has been noticed that due to a hole at the start of physical ram exposed to kernel (i.e. it doesn't start from address 0), the kernel still calculates the 'memstart_addr' kernel variable as 0. Whereas the SYSTEM_RAM or IOMEM_RESERVED range in '/proc/iomem' would carry a first entry whose start address is non-zero (as the physical ram exposed to the kernel starts from a non-zero address). In such cases, if we rely on '/proc/iomem' entries to calculate the phys_offset, then we will have mismatch between the user-space and kernel space 'PHYS_OFFSET' value. The present 'kexec-tools' code does the same in 'get_memory_ranges_iomem_cb()' function when it makes a call to 'set_phys_offset()'. This can cause the vmcore generated via 'kexec-tools' to miss the last few bytes as the first '/proc/iomem' starts from a non-zero address. Please see [0] for the original bug-report from Yanjiang Jin. This patchset tries to fix the same. Details about the patches in this series: ---------------------------------------- PATCH 1/2 -> - Tries to move the elf read functionality from 'vmcore-dmesg.c' to a new utility library named 'elf_info.c', so that subsequent patches can use the same. - See the patch log for more details. PATCH 2/2 -> - Implements the actual functionality of reading the PHYS_OFFSET for arm64 platforms from the kcore (either VMCOREINFO PT_NOTE inside 'kcore' or from the PT_LOAD segments inside 'kcore'). - See the patch log for more details. [0] https://www.spinics.net/lists/kexec/msg20618.html Bhupesh Sharma (2): util_lib: Add functionality to read elf notes arm64: Add support to read PHYS_OFFSET from 'kcore' - pt_note or pt_load (if available) kexec/arch/arm64/kexec-arm64.c | 194 +++++- kexec/arch/arm64/kexec-arm64.h | 15 +- util_lib/Makefile | 4 +- vmcore-dmesg/vmcore-dmesg.c => util_lib/elf_info.c | 193 ++++-- util_lib/include/elf_info.h | 35 + vmcore-dmesg/Makefile | 4 +- vmcore-dmesg/vmcore-dmesg.c | 742 +-------------------- 7 files changed, 386 insertions(+), 801 deletions(-) copy vmcore-dmesg/vmcore-dmesg.c => util_lib/elf_info.c (86%) create mode 100644 util_lib/include/elf_info.h -- 2.7.4 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec