On Sun, Jun 14, 2015 at 03:23:09PM +0200, Denys Vlasenko wrote:
> Th "jmp" deleted by this patch in fact compiles to "jmp to next insn",
> since ".p2align 4,,7" happens to not do any alignment -
> aligning to 2^4 would require more than 7 bytes of padding:
>
> 000000b0 <do_suspend_lowlevel>:
> b0: e8 fc ff ff ff call <save_processor_state>
> b5: e8 8d ff ff ff call 47 <save_registers>
> ba: 6a 03 push $0x3
> bc: e8 fc ff ff ff call <x86_acpi_enter_sleep_state>
> c1: 83 c4 04 add $0x4,%esp
> c4: eb 00 jmp c6 <ret_point> <============ THIS
> 000000c6 <ret_point>:
> c6: e8 c4 ff ff ff call 8f <restore_registers>
>
> Run-tested.
>
> Signed-off-by: Denys Vlasenko <dvlas...@redhat.com>
> CC: Pavel Machek <pa...@ucw.cz>
> CC: Linus Torvalds <torva...@linux-foundation.org>
> CC: Steven Rostedt <rost...@goodmis.org>
> CC: Ingo Molnar <mi...@kernel.org>
> CC: Borislav Petkov <b...@alien8.de>
> CC: "H. Peter Anvin" <h...@zytor.com>
> CC: Andy Lutomirski <l...@amacapital.net>
> CC: Oleg Nesterov <o...@redhat.com>
> CC: Frederic Weisbecker <fweis...@gmail.com>
> CC: Alexei Starovoitov <a...@plumgrid.com>
> CC: Will Drewry <w...@chromium.org>
> CC: Kees Cook <keesc...@chromium.org>
> CC: x...@kernel.org
> CC: linux-kernel@vger.kernel.org
> ---
> arch/x86/kernel/acpi/wakeup_32.S | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/arch/x86/kernel/acpi/wakeup_32.S
> b/arch/x86/kernel/acpi/wakeup_32.S
> index eef2bd3..5fec9b0 100644
> --- a/arch/x86/kernel/acpi/wakeup_32.S
> +++ b/arch/x86/kernel/acpi/wakeup_32.S
> @@ -68,11 +68,8 @@ ENTRY(do_suspend_lowlevel)
> pushl $3
> call x86_acpi_enter_sleep_state
> addl $4, %esp
> +# If S3 fails, we simply fall through to S3 wakeup code:
>
> -# In case of S3 failure, we'll emerge here. Jump
> -# to ret_point to recover
> - jmp ret_point
> - .p2align 4,,7
> ret_point:
> call restore_registers
> call restore_processor_state
Reviewed-by: Borislav Petkov <b...@suse.de>
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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