Saito-san, Thanks for your patch. I think it better to remove __per_cpu_load code, which is unnecessary. ________________________________________ 差出人: kexec <kexec-bounces@xxxxxxxxxxxxxxxxxxx> が saito.kazuya@xxxxxxxxxxx <saito.kazuya@xxxxxxxxxxx> の代理で送信 送信日時: 2020年5月21日 16:15 宛先: 'kexec@xxxxxxxxxxxxxxxxxxx' 件名: [PATCH] sadump: Fix failure of reading __per_cpu_load memory Creating vmcore from sadump by makedumpfile fails with the following error messages since kernel-4.19 with PTI (Page Table Isolation) enabled: __vtop4_x86_64: Can't get a valid pte. readmem: Can't convert a virtual address(ffffffffb2986000) to physical address. readmem: type_addr: 0, addr:ffffffffb2986000, size:8 per_cpu_init: Can't read __per_cpu_load memory. This is caused by the following patch: https://github.com/torvalds/linux/commit/c40a56a7818cfe735fc93a69e1875f8bba834483 The above patch clears _PAGE_PRESENT bit of __per_cpu_load memory, so __vtop4_x86_64 fails to convert the virtual address of the __per_cpu_load. To fix this issue, this patch changes sanity check of per_cpu_ptr() to use address of the __per_cpu_load instead of data of the memory. Signed-off-by: Kazuya Saito <saito.kazuya@xxxxxxxxxxx> Signed-off-by: Kiyotaka Nakamura <kiyo@xxxxxxxxxxx> --- sadump_info.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/sadump_info.c b/sadump_info.c index 46867ce..72a077b 100644 --- a/sadump_info.c +++ b/sadump_info.c @@ -1732,11 +1732,11 @@ per_cpu_init(void) return FALSE; } - if (!readmem(VADDR, SYMBOL(__per_cpu_load), &si->__per_cpu_load, - sizeof(unsigned long))) { - ERRMSG("Can't read __per_cpu_load memory.\n"); + if (SYMBOL(__per_cpu_load) == NOT_FOUND_SYMBOL) { + ERRMSG("Can't find __per_cpu_load symbol.\n"); return FALSE; } + si->__per_cpu_load = SYMBOL(__per_cpu_load); DEBUG_MSG("sadump: __per_cpu_load: %#lx\n", si->__per_cpu_load); DEBUG_MSG("sadump: __per_cpu_offset: LENGTH: %ld\n", -- 2.12.3 _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
