On 22.05.2026 14:33, Teddy Astie wrote:
__{put,get}_guest returns -EFAULT on access faults which causes
the injected cr2 to be off by 14 bytes (as EFAULT is 14) which is
incorrect.
Fix the computation by relying on copy_{from,to}_guest_pv which
reports the number of remaining bytes instead of a negative errno,
such that we can compute the offset properly.
Fixes: 70ad570b2799 ("x86/64: paravirt 32-on-64 call gate support")
Signed-off-by: Teddy Astie <teddy.astie@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
preferably with ...
--- a/xen/arch/x86/pv/emul-gate-op.c
+++ b/xen/arch/x86/pv/emul-gate-op.c
@@ -286,12 +286,14 @@ void pv_emulate_gate_op(struct cpu_user_regs *regs)
if ( !jump )
{
unsigned int ss, esp, *stkp;
+ uint32_t value;
int rc;
#define push(item) do \
{ \
+ value = item; \
... (item) here. I think we're okay without, but let's play safe.
Likely can be adjusted by the committer.
