static int32_t TestSyscall(struct NaClAppThread *natp) {
NaClCopyInDropLock(natp->nap);
NaClTlsSetIdx(0);
return 0;
}
NORETURN void NaClSyscallCSegHook(int32_t tls_idx) {
struct NaClAppThread *natp;
struct NaClApp *nap;
uintptr_t tramp_ret;
size_t sysnum;
uintptr_t sp_user;
uint32_t sysret;
/*
* Mark the thread as running on a trusted stack as soon as possible
* so that we can report any crashes that occur after this point.
*/
NaClStackSafetyNowOnTrustedStack();
natp = nacl_thread[tls_idx];
HandleStackContext(natp, &tramp_ret, &sp_user);
/*
* Before this call, the thread could be suspended, so we should not
* lock any mutexes before this, otherwise it could cause a
* deadlock.
*/
NaClAppThreadSetSuspendState(natp, NACL_APP_THREAD_UNTRUSTED,
NACL_APP_THREAD_TRUSTED);
nap = natp->nap;
NaClLog(4, "Entered NaClSyscallCSegHook\n");
NaClLog(4, "user sp %"NACL_PRIxPTR"\n", sp_user);
NaClCopyInTakeLock(nap);
/*
* held until syscall args are copied, which occurs in the generated
* code.
*/
sysnum = (tramp_ret - (nap->mem_start + NACL_SYSCALL_START_ADDR))
>> NACL_SYSCALL_BLOCK_SHIFT;
NaClLog(4, "system call %"NACL_PRIuS"\n", sysnum);
/*
* usr_syscall_args is used by Decoder functions in
* nacl_syscall_handlers.c which is automatically generated file and
* placed in the
* scons-out/.../gen/native_client/src/trusted/service_runtime/
* directory. usr_syscall_args must point to the first argument of
* a system call. System call arguments are placed on the untrusted
* user stack.
*
* We save the user address for user syscall arguments fetching and
* for VM range locking.
*/
natp->usr_syscall_args = NaClRawUserStackAddrNormalize(sp_user +
NACL_SYSARGS_FIX);
if (sysnum >= NACL_MAX_SYSCALLS) {
NaClLog(2, "INVALID system call %"NACL_PRIdS"\n", sysnum);
sysret = -NACL_ABI_EINVAL;
NaClCopyInDropLock(nap);
} else {
NaClLog(4, "making system call %"NACL_PRIdS", "
"handler 0x%08"NACL_PRIxPTR"\n",
sysnum, (uintptr_t) nap->syscall_table[sysnum].handler);
sysret = (*(nap->syscall_table[sysnum].handler))(natp);
/* Implicitly drops lock */
}
NaClLog(4,
("returning from system call %"NACL_PRIdS", return value %"NACL_PRId32
" (0x%"NACL_PRIx32")\n"),
sysnum, sysret, sysret);
natp->user.sysret = sysret;
NaClLog(4, "return target 0x%08"NACL_PRIxNACL_REG"\n",
natp->user.new_prog_ctr);
NaClLog(4, "user sp %"NACL_PRIxPTR"\n", sp_user);
/*
* After this NaClAppThreadSetSuspendState() call, we should not
* claim any mutexes, otherwise we risk deadlock. Note that if
* NACLVERBOSITY is set high enough to enable the NaClLog() calls in
* NaClSwitchToApp(), these calls could deadlock.
*/
NaClAppThreadSetSuspendState(natp, NACL_APP_THREAD_TRUSTED,
NACL_APP_THREAD_UNTRUSTED);
NaClStackSafetyNowOnUntrustedStack();
NaClSwitchToApp(natp);
/* NOTREACHED */
fprintf(stderr, "NORETURN NaClSwitchToApp returned!?!\n");
NaClAbort();
}
