From 649d6b1019a2f243bc3a98cb85902a8ebf74289a Mon Sep 17 00:00:00 2001 From: Xianting Tian Date: Wed, 26 Oct 2022 22:42:07 +0800 Subject: RISC-V: Add arch_crash_save_vmcoreinfo support 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 Tested-by: Deepak Gupta Tested-by: Guo Ren Acked-by: Baoquan He Link: https://lore.kernel.org/r/20221026144208.373504-2-xianting.tian@linux.alibaba.com [Palmer: wrap commit text] Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/Makefile | 1 + arch/riscv/kernel/crash_core.c | 21 +++++++++++++++++++++ 2 files changed, 22 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..b351a3c01355 --- /dev/null +++ b/arch/riscv/kernel/crash_core.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include +#include + +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 + vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR); +} -- cgit From c5b4216929ebc8ac9107a373db65babc14ba4e80 Mon Sep 17 00:00:00 2001 From: Xianting Tian Date: Wed, 26 Oct 2022 22:42:08 +0800 Subject: Documentation: kdump: describe VMCOREINFO export for RISCV64 The following interrelated definitions and ranges are needed by the kdump crash tool, which are exported by "arch/riscv/kernel/crash_core.c": VA_BITS, PAGE_OFFSET, phys_ram_base, KERNEL_LINK_ADDR, MODULES_VADDR ~ MODULES_END, VMALLOC_START ~ VMALLOC_END, VMEMMAP_START ~ VMEMMAP_END, Document these RISCV64 exports above. Reviewed-by: Bagas Sanjaya Signed-off-by: Xianting Tian Acked-by: Baoquan He Link: https://lore.kernel.org/r/20221026144208.373504-3-xianting.tian@linux.alibaba.com [Palmer: wrap commit text] Signed-off-by: Palmer Dabbelt --- Documentation/admin-guide/kdump/vmcoreinfo.rst | 29 ++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst index 6726f439958c..86fd88492870 100644 --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst @@ -595,3 +595,32 @@ X2TLB ----- Indicates whether the crashed kernel enabled SH extended mode. + +RISCV64 +======= + +VA_BITS +------- + +The maximum number of bits for virtual addresses. Used to compute the +virtual memory ranges. + +PAGE_OFFSET +----------- + +Indicates the virtual kernel start address of the direct-mapped RAM region. + +phys_ram_base +------------- + +Indicates the start physical RAM address. + +MODULES_VADDR|MODULES_END|VMALLOC_START|VMALLOC_END|VMEMMAP_START|VMEMMAP_END|KERNEL_LINK_ADDR +---------------------------------------------------------------------------------------------- + +Used to get the correct ranges: + + * MODULES_VADDR ~ MODULES_END : Kernel module space. + * VMALLOC_START ~ VMALLOC_END : vmalloc() / ioremap() space. + * VMEMMAP_START ~ VMEMMAP_END : vmemmap space, used for struct page array. + * KERNEL_LINK_ADDR : start address of Kernel link and BPF -- cgit