void NaClAppThreadGetSuspendedRegisters(struct NaClAppThread *natp,
struct NaClSignalContext *regs) {
if ((natp->suspend_state & NACL_APP_THREAD_UNTRUSTED) != 0) {
NaClAppThreadGetSuspendedRegistersInternal(natp, regs);
} else {
NaClThreadContextToSignalContext(&natp->user, regs);
}
}
static void TrapSignalHandler(int signal,
const struct NaClSignalContext *context_ptr,
int is_untrusted) {
uint32_t prog_ctr;
char buf[100];
int len;
struct NaClSignalContext *expected_regs = &g_test_shm->expected_regs;
struct NaClSignalContext context = *context_ptr;
if (signal != SIGTRAP) {
SignalSafeLogStringLiteral("Error: Received unexpected signal\n");
_exit(1);
}
/* Get the prog_ctr value relative to untrusted address space. */
prog_ctr = (uint32_t) context.prog_ctr;
/*
* The trampoline code is not untrusted code because it is fixed by
* the TCB. We don't want thread suspension to report prog_ctr as
* being inside the trampoline code because we are not providing any
* DWARF unwind info for the trampoline code. We want the CALL
* instruction that jumps to a syscall trampoline to appear to be
* atomic from the point of view of thread suspension: prog_ctr
* should be reported as either at the CALL or after the CALL.
*
* TODO(mseaborn): Move this range check into the non-test part of
* the thread suspension code.
*/
if (prog_ctr >= NACL_TRAMPOLINE_START && prog_ctr < NACL_TRAMPOLINE_END) {
is_untrusted = 0;
}
if (g_in_untrusted_code != is_untrusted) {
g_context_switch_count++;
g_in_untrusted_code = is_untrusted;
}
if (!*(uint32_t *) NaClUserToSys(g_natp->nap,
(uintptr_t) g_test_shm->regs_should_match))
return;
len = snprintf(buf, sizeof(buf), "prog_ctr=0x%"NACL_PRIxNACL_REG": ",
context.prog_ctr);
SignalSafeWrite(buf, len);
if (is_untrusted) {
SignalSafeLogStringLiteral("Untrusted context\n");
RegsUnsetNonCalleeSavedRegisters(&context);
/*
* Don't compare prog_ctr if we are executing untrusted code.
* Untrusted code executes a small loop for calling the syscall,
* so there are multiple values that prog_ctr can have here.
*/
context.prog_ctr = expected_regs->prog_ctr;
RegsAssertEqual(&context, expected_regs);
} else if ((g_natp->suspend_state & NACL_APP_THREAD_TRUSTED) != 0) {
SignalSafeLogStringLiteral("Trusted (syscall) context\n");
NaClThreadContextToSignalContext(&g_natp->user, &context);
RegsAssertEqual(&context, expected_regs);
} else {
enum NaClUnwindCase unwind_case = 0;
const char *str;
SignalSafeLogStringLiteral("Inside a context switch: ");
NaClGetRegistersForContextSwitch(g_natp, &context, &unwind_case);
str = NaClUnwindCaseToString(unwind_case);
CHECK(str != NULL);
SignalSafeWrite(str, strlen(str));
SignalSafeLogStringLiteral("\n");
RegsAssertEqual(&context, expected_regs);
}
}
