Since RISC-V Linux v6.4, the commit 3335068f87 ("riscv: Use
PUD/P4D/PGD pages for the linear mapping") changes phys_ram_base
from the physical start of the kernel to the actual start of the DRAM.
The Crash-utility's VTOP() still uses phys_ram_base and kernel_map.virt_addr
to translate kernel virtual address, that failed the Crash with Linux v6.4 [1].
Export kernel_map.va_kernel_pa_offset in vmcoreinfo to help Crash translate
the kernel virtual address correctly.
Fixes: 3335068f87 ("riscv: Use PUD/P4D/PGD pages for the linear mapping")
Link: https://lore.kernel.org/linux-riscv/20230724040649.220279-1-suagrfillet@gmail.com/ [1]
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Reviewed-by: Xianting Tian <xianting.tian@linux.alibaba.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230724100917.309061-1-suagrfillet@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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>
Tested-by: Deepak Gupta <debug@rivosinc.com>
Tested-by: Guo Ren <guoren@kernel.org>
Acked-by: Baoquan He <bhe@redhat.com>
Link: https://lore.kernel.org/r/20221026144208.373504-2-xianting.tian@linux.alibaba.com
[Palmer: wrap commit text]
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
