Hi Bhupesh, Baoquan, As for x86_64, I'm going to merge the patch below for fixing the --mem-usage issue with kernel 4.19, if there is no objection. I think the same approach will also work on arm64 with regard to page_offset for the time being..
Thanks, Kazu -- From: Kazuhito Hagio <[email protected]> Date: Fri, 26 Oct 2018 14:43:22 -0400 Subject: [PATCH] x86_64: Fix calculation of page_offset for kernel 4.19 * Required for kernel 4.19 Kernel commit 6855dc41b24619c3d1de3dbd27dd0546b0e45272 ("x86: Add entry trampolines to kcore") added program headers for PTI entry trampoline pages to /proc/kcore. This caused the failure of makedumpfile --mem-usage due to wrong calculation of page_offset. # makedumpfile --mem-usage /proc/kcore [...] set_kcore_vmcoreinfo: Can't get the offset of VMCOREINFO(/proc/kcore). Success makedumpfile Failed. Since program headers for linear maps are located after ones for kernel text and so on in /proc/vmcore and /proc/kcore, with this patch, we use the last valid one to set page_offset. Also, this patch adds a few debug messages for better debugging. Cc: Bhupesh Sharma <[email protected]> Cc: Baoquan He <[email protected]> Signed-off-by: Kazuhito Hagio <[email protected]> --- arch/x86_64.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/x86_64.c b/arch/x86_64.c index 2b3c0bb..ed2a970 100644 --- a/arch/x86_64.c +++ b/arch/x86_64.c @@ -95,10 +95,17 @@ get_page_offset_x86_64(void) ERRMSG("Can't read page_offset_base.\n"); return FALSE; } + DEBUG_MSG("page_offset : %lx (from page_offset_base)\n", + info->page_offset); return TRUE; } if (get_num_pt_loads()) { + /* + * Since program headers for linear maps are located after + * ones for kernel text and so on in /proc/vmcore and + * /proc/kcore, we use the last valid one to set page_offset. + */ for (i = 0; get_pt_load(i, &phys_start, NULL, &virt_start, NULL); i++) { @@ -106,9 +113,13 @@ get_page_offset_x86_64(void) && virt_start < __START_KERNEL_map && phys_start != NOT_PADDR) { info->page_offset = virt_start - phys_start; - return TRUE; } } + if (info->page_offset) { + DEBUG_MSG("page_offset : %lx (from pt_load)\n", + info->page_offset); + return TRUE; + } } if (info->kernel_version < KERNEL_VERSION(2, 6, 27)) { @@ -119,6 +130,7 @@ get_page_offset_x86_64(void) info->page_offset = __PAGE_OFFSET_2_6_27; } + DEBUG_MSG("page_offset : %lx (from constant)\n", info->page_offset); return TRUE; } -- 1.8.3.1 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
