Re: [RESEND PATCH -fixes 1/2] riscv: Export va_kernel_pa_offset in vmcoreinfo

From: Xianting Tian
Date: Mon Jul 24 2023 - 21:52:52 EST



在 2023/7/24 下午6:09, Song Shuai 写道:
Since RISC-V Linux v6.4, the commit 3335068f8721 ("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: 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping")
Link: https://lore.kernel.org/linux-riscv/20230724040649.220279-1-suagrfillet@xxxxxxxxx/ [1]
Signed-off-by: Song Shuai <suagrfillet@xxxxxxxxx>
---
arch/riscv/kernel/crash_core.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/riscv/kernel/crash_core.c b/arch/riscv/kernel/crash_core.c
index b351a3c01355..55f1d7856b54 100644
--- a/arch/riscv/kernel/crash_core.c
+++ b/arch/riscv/kernel/crash_core.c
@@ -18,4 +18,6 @@ void arch_crash_save_vmcoreinfo(void)
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);
+ vmcoreinfo_append_str("NUMBER(va_kernel_pa_offset)=0x%lx\n",
+ kernel_map.va_kernel_pa_offset);
}
Reviewed-by: Xianting Tian  <xianting.tian@xxxxxxxxxxxxxxxxx>