Re: [PATCH v2 2/8] riscv: don't export va_kernel_pa_offset in vmcoreinfo for XIP kernel

Alexandre Ghiti
2024-06-21T10:27:52Z

Hi Nam,

On 07/06/2024 22:22, Nam Cao wrote:
> The crash utility uses va_kernel_pa_offset to translate virtual addresses.
> This is incorrect in the case of XIP kernel, because va_kernel_pa_offset is
> not the virtual-physical address offset (yes, the name is misleading; this
> variable will be removed for XIP in a following commit).
>
> Stop exporting this variable for XIP kernel. The replacement is to be
> determined, note it as a TODO for now.
>
> Signed-off-by: Nam Cao <namcao@linutronix.de>
> ---
> arch/riscv/kernel/vmcore_info.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/arch/riscv/kernel/vmcore_info.c b/arch/riscv/kernel/vmcore_info.c
> index 6d7a22522d63..d5e448aa90e7 100644
> --- a/arch/riscv/kernel/vmcore_info.c
> +++ b/arch/riscv/kernel/vmcore_info.c
> @@ -19,6 +19,13 @@ void arch_crash_save_vmcoreinfo(void)
> #endif
> #endif
> vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR);
> +#ifdef CONFIG_XIP_KERNEL
> + /* TODO: Communicate with crash-utility developers on the information to
> + * export. The XIP case is more complicated, because the virtual-physical
> + * address offset depends on whether the address is in ROM or in RAM.
> + */
> +#else
> vmcoreinfo_append_str("NUMBER(va_kernel_pa_offset)=0x%lx\n",
> kernel_map.va_kernel_pa_offset);
> +#endif
> }

So that will regress crash on XIP kernels, but on the other hand this
was wrong in the first place. And not sure anyone ever used crash on a
XIP platform.

At least people will know that using va_kernel_pa_offset was wrong, so:

Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>

Thanks for all your changes in v2,

Alex