From 6480cc6280e955d1245d8dfb2456d2b830240c74 Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Wed, 10 Aug 2016 10:41:28 +0100 Subject: [PATCH] x86/traps: Fix failed ASSERT() in do_guest_trap() c/s 2e426d6 "x86/traps: Drop use_error_code parameter from do_{,guest_}trap()" introduced an assertion which covered the correctness of shifting 1u by an input parameter. While all other inputs provide a constants vector, the `int $N` handling path from do_general_protection() passes any vector. This path is triggered by XTF, which uses `int 0x20` to facilitate returning to kernel mode after running specific tests in user mode. No vectors above 32 have an error code, so adjust the logic to cope. Reported-by: Wei Liu Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich --- xen/arch/x86/traps.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c index c228b454d4..e822719e95 100644 --- a/xen/arch/x86/traps.c +++ b/xen/arch/x86/traps.c @@ -631,11 +631,8 @@ static void do_guest_trap(unsigned int trapnr, struct vcpu *v = current; struct trap_bounce *tb; const struct trap_info *ti; - bool_t use_error_code; - - ASSERT(trapnr < 32); - - use_error_code = (TRAP_HAVE_EC & (1u << trapnr)); + const bool use_error_code = + ((trapnr < 32) && (TRAP_HAVE_EC & (1u << trapnr))); trace_pv_trap(trapnr, regs->eip, use_error_code, regs->error_code); -- 2.30.2