Thanks Bhupesh for replying On Wed, Nov 27, 2019 at 2:42 AM Bhupesh Sharma <bhsharma@xxxxxxxxxx> wrote: > > Hi Prabhakar, > > On Tue, Nov 26, 2019 at 1:04 PM Prabhakar Kushwaha > <prabhakar.pkin@xxxxxxxxx> wrote: > > > > Hi All, > > > > I am facing issue below error with latest kexec-tools/vmcore-demsg tools. > > > > $ ./build/sbin/vmcore-dmesg /proc/vmcore > > No program header covering vaddr 0xffff000be7a00000found kexec bug? > > > > I am testing on AARM64 platform with following git repos. > > A) kexec tools: > > https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git > > top commit: bd077966e2b9041c (kexec-tools: Fix conversion overflow > > when compiling on 32-bit platforms) > > > > B) Linux:git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > > top commit: af42d3466bdc8f3980 (Linux 5.4-rc8) > > > > I am seeing similar issue in past also in couple of discussions. has > > it not fixed earlier or it keep arises with time to time > > > > Please suggest. > > Thanks for reporting the issue. > I think the issue with the latest ARM64 kernel and kexec-tools is the > same as the makedumpfile, i.e. the PAGE_OFFSET calculation needs to be > dynamically done for 52-bit VA_BITS correctly as well. > Yes we need dynamic approach of calculating VA_BITS. Please note, the AARM64 platform used by us is 48Bit. CONFIG_ARM64_VA_BITS_48=y CONFIG_ARM64_VA_BITS=48 CONFIG_ARM64_PA_BITS_48=y CONFIG_ARM64_PA_BITS=48 As per my understanding, this issue is not because of 52 bit. It is due to patch 14c127c957c1 ("arm64: mm: Flip kernel VA space") in Linux. i.e. PAGE_OFFSET address has been moved to bottom instead of middle in kernel virtual address space. As below changes solves mentioned kexec-tools/vmcore-demsg problem. diff --git a/kexec/arch/arm64/crashdump-arm64.c b/kexec/arch/arm64/crashdump-arm64.c index 4fd7aa8..1c28b06 100644 --- a/kexec/arch/arm64/crashdump-arm64.c +++ b/kexec/arch/arm64/crashdump-arm64.c @@ -58,6 +58,8 @@ static uint64_t get_kernel_page_offset(void) { int i; + return 0xffff000000000000; --> PAGE_OFFSET if (elf_info.kern_vaddr_start == UINT64_MAX) return UINT64_MAX; Also, I verified by moving one patch below 14c127c957c1 in Linux, no changes required in kexect-tools. Everything works fine. The calculation used in makedumpfile (your patches), indirectly takes care of this. So we need similar calculation here in kexec also. --pk _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
