Hello Liu,
That works -- but I think the addition of the next_symbol_value() function
is over-kill, and it introduces an unnecessary (although presumably impossible)
FATAL error. Why not simplify it to do something like this:
if ((string = pc->read_vmcoreinfo("CONFIG_ARM_LPAE"))) {
machdep->flags |= PAE;
free(string);
} else if ((sp = next_symbol("swapper_pg_dir")) &&
(sp->value - symbol_value("swapper_pg_dir")) == 0x5000))
machdep->flags |= PAE;
Thanks,
Dave
----- Original Message -----
> Thanks to Dave's suggest, I impove the way to identify
> LPAE enabled kernel for arm platform, for compatibility with
> some old kernel.
>
> If a vmcore santisfy one of the following conditions, It must
> be generated by a LPAE enabled kernel.
>
> (1) it has CONFIG_ARM_LPAE=y vmcore_info
> (2) swapper_pg_dir and its next symbol value differ by 0x5000
>
> Signed-off-by: Liu Hua <sdu.liu@xxxxxxxxxx>
> ---
> arm.c | 11 ++++++++++-
> symbols.c | 10 ++++++++++
> 2 files changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/arm.c b/arm.c
> index cb7d841..76ba699 100644
> --- a/arm.c
> +++ b/arm.c
> @@ -190,6 +190,8 @@ void
> arm_init(int when)
> {
> ulong vaddr;
> + char *string;
> + ulong difference;
>
> #if defined(__i386__) || defined(__x86_64__)
> if (ACTIVE())
> @@ -229,8 +231,15 @@ arm_init(int when)
> * LPAE requires an additional page for the PGD,
> * so PG_DIR_SIZE = 0x5000 for LPAE
> */
> - if ((symbol_value("_text") - symbol_value("swapper_pg_dir")) == 0x5000)
> + if ((string = pc->read_vmcoreinfo("CONFIG_ARM_LPAE"))) {
> machdep->flags |= PAE;
> + free(string);
> + } else {
> + difference = next_symbol_value("swapper_pg_dir", NULL)
> + - symbol_value("swapper_pg_dir");
> + if (difference == 0x5000)
> + machdep->flags |= PAE;
> + }
> machdep->kvbase = symbol_value("_stext") & ~KVBASE_MASK;
> machdep->identity_map_base = machdep->kvbase;
> machdep->is_kvaddr = arm_is_kvaddr;
> diff --git a/symbols.c b/symbols.c
> index a0f256e..b294cd2 100644
> --- a/symbols.c
> +++ b/symbols.c
> @@ -4936,6 +4936,16 @@ try_get_symbol_data(char *symbol, long size, void
> *local)
> return FALSE;
> }
>
> +ulong
> +next_symbol_value(char *symbol, struct syment *psb)
> +{
> + struct syment *sp;
> +
> + if (!(sp = next_symbol(symbol, psb)))
> + error(FATAL, "cannot resolve \"%s\"\n", symbol);
> + return(sp->value);
> +}
> +
> /*
> * Return the value of a given symbol.
> */
> --
> 1.9.0
>
>
--
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