On Mon, Jan 07, 2019 at 04:22:49PM +0530, Bhupesh Sharma wrote: > 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, and sorry for the delay. I have applied this series. _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
