-----Original Message-----
> After kernel commit e2a073dde921 ("arm64: omit [_text, _stext) from
> permanent kernel mapping"), the range [_text, _stext] is reclaimed. But
> the current crash code still assumes kernel starting from "_text".
>
> This change only affects the vmalloced area on arm64 and may result a
> false in arm64_IS_VMALLOC_ADDR().
>
> Since vmcore has no extra information about this trival change, it can
> only be deduced from kernel version, which means ms->kimage_text can not
> be correctly initialized until kernel_init() finishes. Here on arm64, it
> can be done at the point machdep_init(POST_GDB). This is fine
> since there is no access to vmalloced area at this stage.
>
> Signed-off-by: Pingfan Liu <piliu@xxxxxxxxxx>
Thanks for the v2. Assuming the patch was tested,
Acked-by: Kazuhito Hagio <k-hagio-ab@xxxxxxx>
Kazu
> ---
> arm64.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/arm64.c b/arm64.c
> index de1038a..3ab8489 100644
> --- a/arm64.c
> +++ b/arm64.c
> @@ -92,6 +92,20 @@ static void arm64_calc_VA_BITS(void);
> static int arm64_is_uvaddr(ulong, struct task_context *);
> static void arm64_calc_KERNELPACMASK(void);
>
> +static void arm64_calc_kernel_start(void)
> +{
> + struct machine_specific *ms = machdep->machspec;
> + struct syment *sp;
> +
> + if (THIS_KERNEL_VERSION >= LINUX(5,11,0))
> + sp = kernel_symbol_search("_stext");
> + else
> + sp = kernel_symbol_search("_text");
> +
> + ms->kimage_text = (sp ? sp->value : 0);
> + sp = kernel_symbol_search("_end");
> + ms->kimage_end = (sp ? sp->value : 0);
> +}
>
> /*
> * Do all necessary machine-specific setup here. This is called several times
> @@ -241,6 +255,7 @@ arm64_init(int when)
> if (machdep->flags & NEW_VMEMMAP) {
> struct syment *sp;
>
> + /* It is finally decided in arm64_calc_kernel_start() */
> sp = kernel_symbol_search("_text");
> ms->kimage_text = (sp ? sp->value : 0);
> sp = kernel_symbol_search("_end");
> @@ -387,6 +402,8 @@ arm64_init(int when)
> break;
>
> case POST_GDB:
> + /* Rely on kernel version to decide the kernel start address */
> + arm64_calc_kernel_start();
> arm64_calc_virtual_memory_ranges();
> arm64_get_section_size_bits();
>
> --
> 2.31.1
--
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