Messages in this thread | | | Date | Thu, 20 Oct 2022 12:40:24 +0800 | Subject | Re: [PATCH V4 1/2] RISC-V: Add arch_crash_save_vmcoreinfo support | From | Xianting Tian <> |
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在 2022/10/20 上午11:05, Baoquan He 写道: > On 10/20/22 at 10:17am, Xianting Tian wrote: >> 在 2022/10/20 上午10:08, Baoquan He 写道: >>> On 10/19/22 at 06:36pm, Xianting Tian wrote: >>>> Add arch_crash_save_vmcoreinfo(), which exports VM layout(MODULES, VMALLOC, >>>> VMEMMAP ranges and KERNEL_LINK_ADDR), 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@linux.alibaba.com> >>>> --- >>>> arch/riscv/kernel/Makefile | 1 + >>>> arch/riscv/kernel/crash_core.c | 23 +++++++++++++++++++++++ >>>> 2 files changed, 24 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..3e889d0ed7bd >>>> --- /dev/null >>>> +++ b/arch/riscv/kernel/crash_core.c >>>> @@ -0,0 +1,23 @@ >>>> +// 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)) >>>> + vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR); >>> Wondering why you don't put KERNEL_LINK_ADDR exporting into the above >>> ifdeffery scope, with that you can save one line of "IS_ENABLED(CONFIG_64BIT)". >> I followed the rule in print_vm_layout() of arch/riscv/mm/init.c, which used >> IS_ENABLED when print the value of KERNEL_LINK_ADDR. >> > I see. There's PAGE_OFFSET in the middle. Thanks. > > print_ml("lowmem", (unsigned long)PAGE_OFFSET, > (unsigned long)high_memory) > > So now, do you think if it's necessary to have another > IS_ENABLED(CONFIG_64BIT) in the current arch_crash_save_vmcoreinfo()?
For which MACRO? I think current code for PAGE_OFFSET is OK.
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