Messages in this thread | | | Subject | Re: [PATCH v3 1/2] x86/xen: Make the boot CPU idle task reliable | From | Jürgen Groß <> | Date | Thu, 26 Mar 2020 10:29:40 +0100 |
| |
On 26.03.20 10:26, Miroslav Benes wrote: > The unwinder reports the boot CPU idle task's stack on XEN PV as > unreliable, which affects at least live patching. There are two reasons > for this. First, the task does not follow the x86 convention that its > stack starts at the offset right below saved pt_regs. It allows the > unwinder to easily detect the end of the stack and verify it. Second, > startup_xen() function does not store the return address before jumping > to xen_start_kernel() which confuses the unwinder. > > Amend both issues by moving the starting point of initial stack in > startup_xen() and storing the return address before the jump, which is > exactly what call instruction does. > > Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Juergen Gross <jgross@suse.com>
Juergen
| |