From: Joerg Roedel <[email protected]> When an instruction is fetched from user-space, segmentation needs to be taken into account. This means that getting the linear address of an instruction can fail. Hardware would raise a #GP exception in that case, but the #VC exception handler would emulate it as a page-fault.
The insn_fetch_from_user*() functions now provide the relevant information in case of an failure. Use that and propagate a #GP when the linear address of an instruction to fetch could not be calculated. Signed-off-by: Joerg Roedel <[email protected]> --- arch/x86/kernel/sev.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 1edb6cd5e308..4736290361e4 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -261,11 +261,16 @@ static enum es_result __vc_decode_user_insn(struct es_em_ctxt *ctxt) int insn_bytes = 0, res; res = insn_fetch_from_user_inatomic(ctxt->regs, buffer, &insn_bytes); - if (res) { + if (res == -EFAULT) { ctxt->fi.vector = X86_TRAP_PF; ctxt->fi.error_code = X86_PF_INSTR | X86_PF_USER; ctxt->fi.cr2 = ctxt->regs->ip; return ES_EXCEPTION; + } else if (res == -EINVAL) { + ctxt->fi.vector = X86_TRAP_GP; + ctxt->fi.error_code = 0; + ctxt->fi.cr2 = 0; + return ES_EXCEPTION; } if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, insn_bytes)) -- 2.31.1 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
