Hi Pingfan,
thanks for the patch.
-----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. This is fine
> since there is no access to vmalloced area at this early stage.
>
> Signed-off-by: Pingfan Liu <[email protected]>
> ---
> arm64.c | 17 +++++++++++++++++
> defs.h | 1 +
> kernel.c | 3 +++
> 3 files changed, 21 insertions(+)
>
> diff --git a/arm64.c b/arm64.c
> index 4f2c2b5..4aa971c 100644
> --- a/arm64.c
> +++ b/arm64.c
> @@ -92,6 +92,21 @@ static void arm64_calc_VA_BITS(void);
> static int arm64_is_uvaddr(ulong, struct task_context *);
> static void arm64_calc_KERNELPACMASK(void);
>
> +/* called by kernel_init() */
> +static void arm64_post_kernel_init(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
> @@ -104,6 +119,7 @@ arm64_init(int when)
> char *string;
> struct machine_specific *ms;
>
> + arch_post_kernel_init = arm64_post_kernel_init;
Why is the arch_post_kernel_init needed, i.e. can't we put it in
machdep_init(POST_GDB)?
Thanks,
Kazu
> #if defined(__x86_64__)
> if (ACTIVE())
> error(FATAL, "compiled for the ARM64 architecture\n");
> @@ -241,6 +257,7 @@ arm64_init(int when)
> if (machdep->flags & NEW_VMEMMAP) {
> struct syment *sp;
>
> + /* It is finally decided in arm64_post_kernel_init() */
> sp = kernel_symbol_search("_text");
> ms->kimage_text = (sp ? sp->value : 0);
> sp = kernel_symbol_search("_end");
> diff --git a/defs.h b/defs.h
> index 7d386d2..04ab55a 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -5677,6 +5677,7 @@ struct command_table_entry *crash_cmd_table(void);
> /*
> * kernel.c
> */
> +extern void (*arch_post_kernel_init)(void);
> void kernel_init(void);
> void module_init(void);
> void verify_version(void);
> diff --git a/kernel.c b/kernel.c
> index 9c4aabf..b64ffac 100644
> --- a/kernel.c
> +++ b/kernel.c
> @@ -98,6 +98,7 @@ static char *vmcoreinfo_read_string(const char *);
> static void check_vmcoreinfo(void);
> static int is_pvops_xen(void);
>
> +void (*arch_post_kernel_init)(void);
>
> /*
> * Gather a few kernel basics.
> @@ -823,6 +824,8 @@ kernel_init()
> source_tree_init();
>
> kt->flags &= ~PRE_KERNEL_INIT;
> + if (arch_post_kernel_init)
> + arch_post_kernel_init();
> }
>
> /*
> --
> 2.31.1
>
> --
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