On 6/26/20 1:21 PM, Andy Lutomirski wrote:
> The SYSENTER frame setup was nonsense. It worked by accident
> because the normal code into which the Xen asm jumped
> (entry_SYSENTER_32/compat) threw away SP without touching the stack.
> entry_SYSENTER_compat was recently modified such that it relied on
> having a valid stack pointer, so now the Xen asm needs to invoke it
> with a valid stack.
>
> Fix it up like SYSCALL: use the Xen-provided frame and skip the bare
> metal prologue.
>
> Cc: Boris Ostrovsky <boris.ostrov...@oracle.com>
> Cc: Juergen Gross <jgr...@suse.com>
> Cc: Stefano Stabellini <sstabell...@kernel.org>
> Cc: xen-de...@lists.xenproject.org
> Fixes: 1c3e5d3f60e2 ("x86/entry: Make entry_64_compat.S objtool clean")
> Signed-off-by: Andy Lutomirski <l...@kernel.org>
Reviewed-by: Boris Ostrovsky <boris.ostrov...@oracle.com>
