Hi Simon, On Thu, Dec 20, 2018 at 4:52 PM Bhupesh Sharma <bhsharma@xxxxxxxxxx> wrote: > > 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 Ping. Since this fixes a pending known issue on arm64 boards (both for KASLR and non-KASLR boot cases) can we please pick this patch-set for upstream kexec-tools. Thanks, Bhupesh _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
