Commit ec05090403ef4d760fbe701e31afd0f0edc414d5 ("x86/entry: Erase guest
GPR state on entry to Xen") zero-ed %rbp, compat arg 6, but it is not
restored before passing to hypercalls. We need to pass the saved compat
arg 6 to the hypercall in r9, the 6th function argument.
Signed-off-by: Jason Andryuk <jandr...@gmail.com>
---
This is against Xen 4.6. I believe it is also applicable to 4.7.
xen/arch/x86/x86_64/compat/entry.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/xen/arch/x86/x86_64/compat/entry.S
b/xen/arch/x86/x86_64/compat/entry.S
index bc1f509672..b99b142e45 100644
--- a/xen/arch/x86/x86_64/compat/entry.S
+++ b/xen/arch/x86/x86_64/compat/entry.S
@@ -56,7 +56,7 @@ UNLIKELY_END(msi_check)
xchgl %ecx,%esi /* Arg 2, Arg 4 */
movl %edx,%edx /* Arg 3 */
movl %edi,%r8d /* Arg 5 */
- movl %ebp,%r9d /* Arg 6 */
+ movl UREGS_rbp(%rsp),%r9d /* Arg 6 */
movl UREGS_rbx(%rsp),%edi /* Arg 1 */
#define SHADOW_BYTES 0 /* No on-stack shadow state */
#endif
--
2.14.3
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