Re: [Crash-utility] [PATCH V4 1/2] RISC-V: Add arch_crash_save_vmcoreinfo support

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(a)linux.alibaba.com&gt; > > --- > > 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.