x86/xen: Make the secondary CPU idle tasks reliable
commit c3881eb5 upstream. The unwinder reports the secondary CPU idle tasks' stack on XEN PV as unreliable, which affects at least live patching. cpu_initialize_context() sets up the context of the CPU through VCPUOP_initialise hypercall. After it is woken up, the idle task starts in cpu_bringup_and_idle() function and its stack starts at the offset right below pt_regs. The unwinder correctly detects the end of stack there but it is confused by NULL return address in the last frame. Introduce a wrapper in assembly, which just calls cpu_bringup_and_idle(). The return address is thus pushed on the stack and the wrapper contains the annotation hint for the unwinder regarding the stack state. Signed-off-by:Miroslav Benes <mbenes@suse.cz> Reviewed-by:
Juergen Gross <jgross@suse.com> Signed-off-by:
Juergen Gross <jgross@suse.com> Signed-off-by:
Markus Boehme <markubo@amazon.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parent
0d3817cb
Please register or sign in to comment