Re: [Crash-utility] [PATCH V3 1/2] RISC-V: Add arch_crash_save_vmcoreinfo support

在 2022/10/18 下午6:03, Baoquan He 写道: > On 10/18/22 at 05:25pm, Xianting Tian wrote: >> 在 2022/10/18 下午5:10, Baoquan He 写道: >>> On 10/18/22 at 04:17pm, Xianting Tian wrote: >>>> Add arch_crash_save_vmcoreinfo(), which exports VM layout(MODULES, VMALLOC, >>>> VMEMMAP and KERNEL_LINK_ADDR ranges), va bits and ram base for vmcore. >>>> >>>> Default pagetable levels and PAGE_OFFSET aren't same for different kernel >>>> version as below. For pagetable levels, it sets sv57 by default and falls >>>> back to setting sv48 at boot time if sv57 is not supported by the hardware. >>>> >>>> For ram base, the default value is 0x80200000 for qemu riscv64 env and, >>>> for example, is 0x200000 on the XuanTie 910 CPU. >>>> >>>>    * Linux Kernel 5.18 ~ >>>>    *      PGTABLE_LEVELS = 5 >>>>    *      PAGE_OFFSET = 0xff60000000000000 >>>>    * Linux Kernel 5.17 ~ >>>>    *      PGTABLE_LEVELS = 4 >>>>    *      PAGE_OFFSET = 0xffffaf8000000000 >>>>    * Linux Kernel 4.19 ~ >>>>    *      PGTABLE_LEVELS = 3 >>>>    *      PAGE_OFFSET = 0xffffffe000000000 >>>> >>>> Since these configurations change from time to time and version to version, >>>> it is preferable to export them via vmcoreinfo than to change the crash's >>>> code frequently, it can simplify the development of crash tool. >>>> >>>> Signed-off-by: Xianting Tian <xianting.tian(a)linux.alibaba.com&gt; >>>> --- >>>>    arch/riscv/kernel/Makefile     |  1 + >>>>    arch/riscv/kernel/crash_core.c | 29 +++++++++++++++++++++++++++++ >>>>    2 files changed, 30 insertions(+) >>>>    create mode 100644 arch/riscv/kernel/crash_core.c >>>> >>>> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile >>>> index db6e4b1294ba..4cf303a779ab 100644 >>>> --- a/arch/riscv/kernel/Makefile >>>> +++ b/arch/riscv/kernel/Makefile >>>> @@ -81,6 +81,7 @@ obj-$(CONFIG_KGDB)        += kgdb.o >>>>    obj-$(CONFIG_KEXEC_CORE)    += kexec_relocate.o crash_save_regs.o machine_kexec.o >>>>    obj-$(CONFIG_KEXEC_FILE)    += elf_kexec.o machine_kexec_file.o >>>>    obj-$(CONFIG_CRASH_DUMP)    += crash_dump.o >>>> +obj-$(CONFIG_CRASH_CORE)    += crash_core.o >>>>    obj-$(CONFIG_JUMP_LABEL)    += jump_label.o >>>> diff --git a/arch/riscv/kernel/crash_core.c b/arch/riscv/kernel/crash_core.c >>>> new file mode 100644 >>>> index 000000000000..8d7f5ff108da >>>> --- /dev/null >>>> +++ b/arch/riscv/kernel/crash_core.c >>>> @@ -0,0 +1,29 @@ >>>> +// SPDX-License-Identifier: GPL-2.0-only >>>> + >>>> +#include <linux/crash_core.h> >>>> +#include <linux/pagemap.h> >>>> + >>>> +void arch_crash_save_vmcoreinfo(void) >>>> +{ >>>> +    VMCOREINFO_NUMBER(VA_BITS); >>>> +    VMCOREINFO_NUMBER(phys_ram_base); >>>> + >>>> +    vmcoreinfo_append_str("NUMBER(PAGE_OFFSET)=0x%lx\n", PAGE_OFFSET); >>>> +    vmcoreinfo_append_str("NUMBER(VMALLOC_START)=0x%lx\n", VMALLOC_START); >>>> +    vmcoreinfo_append_str("NUMBER(VMALLOC_END)=0x%lx\n", VMALLOC_END); >>>> +    vmcoreinfo_append_str("NUMBER(VMEMMAP_START)=0x%lx\n", VMEMMAP_START); >>>> +    vmcoreinfo_append_str("NUMBER(VMEMMAP_END)=0x%lx\n", VMEMMAP_END); >>>> +#ifdef CONFIG_64BIT >>>> +    vmcoreinfo_append_str("NUMBER(MODULES_VADDR)=0x%lx\n", MODULES_VADDR); >>>> +    vmcoreinfo_append_str("NUMBER(MODULES_END)=0x%lx\n", MODULES_END); >>>> +#endif >>>> + >>>> +    if (IS_ENABLED(CONFIG_64BIT)) { >>>> +#ifdef CONFIG_KASAN >>>> +        vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_START)=0x%lx\n", KASAN_SHADOW_START); >>>> +        vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_END)=0x%lx\n", KASAN_SHADOW_END); >>>> +#endif >>>> +        vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR); >>>> +        vmcoreinfo_append_str("NUMBER(ADDRESS_SPACE_END)=0x%lx\n", ADDRESS_SPACE_END); >>> Seems this is the firsr ARCH where kasan and kernel link/bpf space are >>> added to dump and analyze. Just curious, have you got code change to >>> make use of them to do dumping and analyze? >> KASAN_SHADOW_START is not used, KERNEL_LINK_ADDR is used in the crash patch set: >> https://patchwork.kernel.org/project/linux-riscv/cover/20220813031753.309... > Oh, I would say please no. Sometime we got tons of objection when adding an > necessary one, we definitely should not add one for possible future > use. > > For this kind of newly added one, we need get ack from > makedumpfile/crash utility maintainer so that we know they are necessary > to have. At least they don't oppose. Hi Kazu, Li Jiang Could you help comment whether we need KASAN_SHADOW_START and KERNEL_LINK_ADDR area export for vmcore from crash point of view？ In my crash patch set, I don't use KASAN_SHADOW_START, And only get the value of KERNEL_LINK_ADDR, not realy use it. https://patchwork.kernel.org/project/linux-riscv/cover/20220813031753.309...