File 5f1a9916-x86-S3-put-data-sregs-into-known-state... of Package xen

Overview Repositories Revisions Requests Users Attributes Meta

File 5f1a9916-x86-S3-put-data-sregs-into-known-state.patch of Package xen (Revision d4df08e2f3fe7a86db20018815932372)

Currently displaying revision d4df08e2f3fe7a86db20018815932372 , Show latest

# Commit 55f8c389d4348cc517946fdcb10794112458e81e
# Date 2020-07-24 10:17:26 +0200
# Author Jan Beulich <jbeulich@suse.com>
# Committer Jan Beulich <jbeulich@suse.com>
x86/S3: put data segment registers into known state upon resume

wakeup_32 sets %ds and %es to BOOT_DS, while leaving %fs at what
wakeup_start did set it to, and %gs at whatever BIOS did load into it.
All of this may end up confusing the first load_segments() to run on
the BSP after resume, in particular allowing a non-nul selector value
to be left in %fs.

Alongside %ss, also put all other data segment registers into the same
state that the boot and CPU bringup paths put them in.

Reported-by: M. Vefa Bicakci <m.v.b@runbox.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

--- a/xen/arch/x86/acpi/wakeup_prot.S
+++ b/xen/arch/x86/acpi/wakeup_prot.S
@@ -49,6 +49,10 @@ ENTRY(s3_resume)
         mov     %rax, %cr0
 
         mov     $__HYPERVISOR_DS64, %eax
+        mov     %eax, %ds
+        mov     %eax, %es
+        mov     %eax, %fs
+        mov     %eax, %gs
         mov     %eax, %ss
         mov     saved_rsp(%rip), %rsp

Places

File 5f1a9916-x86-S3-put-data-sregs-into-known-state.patch of Package xen (Revision d4df08e2f3fe7a86db20018815932372)

Places