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From:   Song Shuai <suagrfillet@gmail.com>
To:     bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com,
        corbet@lwn.net, paul.walmsley@sifive.com, palmer@dabbelt.com,
        aou@eecs.berkeley.edu, xianting.tian@linux.alibaba.com,
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        conor.dooley@microchip.com
Cc:     kexec@lists.infradead.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org
Subject: [RESEND PATCH -fixes 1/2] riscv: Export va_kernel_pa_offset in vmcoreinfo
Date:   Mon, 24 Jul 2023 18:09:16 +0800
Message-Id: <20230724100917.309061-1-suagrfillet@gmail.com>
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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@gmail.com/ [1]
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
---
 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);
 }
-- 
2.20.1