On Fri, Sep 04, 2015 at 03:23:05PM +0100, Jungseok Lee wrote:
> Under EL1h, S_SP data is not seen in kernel_exit. Thus, x21 calculation
> is not needed in kernel_entry. Currently, S_SP information is vaild only
> when sp_el0 is used.
I don't think this is true. The generic BUG implementation will grab the
saved SP from the pt_regs, and with this change we'll report whatever
happened to be in x21 instead.
> Signed-off-by: Jungseok Lee <jungseokle...@gmail.com>
> ---
> arch/arm64/kernel/entry.S | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index e163518..d23ca0d 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -91,8 +91,6 @@
> get_thread_info tsk // Ensure MDSCR_EL1.SS is clear,
> ldr x19, [tsk, #TI_FLAGS] // since we can unmask debug
> disable_step_tsk x19, x20 // exceptions when scheduling.
> - .else
> - add x21, sp, #S_FRAME_SIZE
> .endif
> mrs x22, elr_el1
> mrs x23, spsr_el1
Immediately after this we do:
stp lr, x21, [sp, #S_LR]
To store the LR and SP to the pt_regs which bug_handler would use.
Am I missing smoething?
Thanks,
Mark.
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