Messages in this thread | | | Date | Wed, 26 Oct 2022 22:24:05 +0800 | Subject | Re: [PATCH V4 1/2] RISC-V: Add arch_crash_save_vmcoreinfo support | From | Xianting Tian <> |
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在 2022/10/26 下午9:47, Conor Dooley 写道: > On Wed, Oct 26, 2022 at 08:05:41PM +0800, Baoquan He wrote: >> Hi Xianting, >> >> On 10/26/22 at 05:44pm, Xianting Tian wrote: >>> 在 2022/10/26 下午5:25, Conor Dooley 写道: >>>> On Wed, Oct 26, 2022 at 05:08:11PM +0800, Xianting Tian wrote: >>>>> Hi Palmer, Conor >>>>> >>>>> Is this version OK for you? >>>> The weird ifdef/IS_ENABLED thing was the only comment I had. It's a bit >>>> odd & I notice Baoquan brought it up too. I didn't (and won't) give you >>>> a reviewed by on these patches because I don't understand the area well >>>> enough. The general nitpickery seems to be sorted though. >>> I checked the KERNEL_LINK_ADDR definition of riscv, it is valid for >>> CONFIG_64BIT and !CONFIG_64BIT. >> This series looks good to me. My only minor concern is if we can make >> the arch_crash_save_vmcoreinfo() as below. I don't understand why we >> have to have the CONFIG_64BIT ifdeffery and the IS_ENABLED(CONFIG_64BIT) >> between two adjacent code blocks. Not sure if we are saying the same >> thing. > I think we can just go and drop the IS_ENABLED(). From looking at it > last time, one bit is compileable (but not usable) for !64BIT and the > other isn't hence the IS_ENABLED(). I think it would make sense to drop > the IS_ENABLED() - I don't think we're too likely to hit some compile > testing edge cases that IS_ENABLED() would help with & only having one > makes the code look a lot less odd and a lot more intentional. thanks, I will send V5 patch for review. > >> +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); >> + vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR); >> +#endif >> +} >> >>> Maybe we can remove IS_ENABLED(CONFIG_64BIT) >>> >>> arch/riscv/include/asm/pgtable.h >>> #define ADDRESS_SPACE_END (UL(-1)) >>> #ifdef CONFIG_64BIT >>> /* Leave 2GB for kernel and BPF at the end of the address space */ >>> #define KERNEL_LINK_ADDR (ADDRESS_SPACE_END - SZ_2G + 1) >>> #else >>> #define KERNEL_LINK_ADDR PAGE_OFFSET >>> #endif >>> >>> arch/riscv/include/asm/page.h >>> #ifdef CONFIG_64BIT >>> #ifdef CONFIG_MMU >>> #define PAGE_OFFSET kernel_map.page_offset >>> #else >>> #define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL) >>> #endif >>> /* >>> * By default, CONFIG_PAGE_OFFSET value corresponds to SV48 address space so >>> * define the PAGE_OFFSET value for SV39. >>> */ >>> #define PAGE_OFFSET_L4 _AC(0xffffaf8000000000, UL) >>> #define PAGE_OFFSET_L3 _AC(0xffffffd800000000, UL) >>> #else >>> #define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL) >>> #endif /* CONFIG_64BIT */ >>> >>>> Thanks, >>>> Conor. >>>> >>>>> 在 2022/10/20 下午12:40, Xianting Tian 写道: >>>>>> 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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