| // Copyright 2011 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| #include "runtime.h" |
| #include "defs_GOOS_GOARCH.h" |
| #include "os_GOOS.h" |
| #include "signal_unix.h" |
| #include "stack.h" |
| #include "../../cmd/ld/textflag.h" |
| |
| enum |
| { |
| ESRCH = 3, |
| ENOTSUP = 91, |
| |
| // From NetBSD's <sys/time.h> |
| CLOCK_REALTIME = 0, |
| CLOCK_VIRTUAL = 1, |
| CLOCK_PROF = 2, |
| CLOCK_MONOTONIC = 3 |
| }; |
| |
| extern SigTab runtime·sigtab[]; |
| |
| static Sigset sigset_none; |
| static Sigset sigset_all = { ~(uint32)0, ~(uint32)0, ~(uint32)0, ~(uint32)0, }; |
| |
| extern void runtime·getcontext(UcontextT *context); |
| extern int32 runtime·lwp_create(UcontextT *context, uintptr flags, void *lwpid); |
| extern void runtime·lwp_mcontext_init(void *mc, void *stack, M *mp, G *gp, void (*fn)(void)); |
| extern int32 runtime·lwp_park(Timespec *abstime, int32 unpark, void *hint, void *unparkhint); |
| extern int32 runtime·lwp_unpark(int32 lwp, void *hint); |
| extern int32 runtime·lwp_self(void); |
| |
| // From NetBSD's <sys/sysctl.h> |
| #define CTL_HW 6 |
| #define HW_NCPU 3 |
| |
| static int32 |
| getncpu(void) |
| { |
| uint32 mib[2]; |
| uint32 out; |
| int32 ret; |
| uintptr nout; |
| |
| // Fetch hw.ncpu via sysctl. |
| mib[0] = CTL_HW; |
| mib[1] = HW_NCPU; |
| nout = sizeof out; |
| out = 0; |
| ret = runtime·sysctl(mib, 2, (byte*)&out, &nout, nil, 0); |
| if(ret >= 0) |
| return out; |
| else |
| return 1; |
| } |
| |
| uintptr |
| runtime·semacreate(void) |
| { |
| return 1; |
| } |
| |
| #pragma textflag NOSPLIT |
| int32 |
| runtime·semasleep(int64 ns) |
| { |
| Timespec ts; |
| |
| // spin-mutex lock |
| while(runtime·xchg(&m->waitsemalock, 1)) |
| runtime·osyield(); |
| |
| for(;;) { |
| // lock held |
| if(m->waitsemacount == 0) { |
| // sleep until semaphore != 0 or timeout. |
| // thrsleep unlocks m->waitsemalock. |
| if(ns < 0) { |
| // TODO(jsing) - potential deadlock! |
| // |
| // There is a potential deadlock here since we |
| // have to release the waitsemalock mutex |
| // before we call lwp_park() to suspend the |
| // thread. This allows another thread to |
| // release the lock and call lwp_unpark() |
| // before the thread is actually suspended. |
| // If this occurs the current thread will end |
| // up sleeping indefinitely. Unfortunately |
| // the NetBSD kernel does not appear to provide |
| // a mechanism for unlocking the userspace |
| // mutex once the thread is actually parked. |
| runtime·atomicstore(&m->waitsemalock, 0); |
| runtime·lwp_park(nil, 0, &m->waitsemacount, nil); |
| } else { |
| ns = ns + runtime·nanotime(); |
| // NOTE: tv_nsec is int64 on amd64, so this assumes a little-endian system. |
| ts.tv_nsec = 0; |
| ts.tv_sec = runtime·timediv(ns, 1000000000, (int32*)&ts.tv_nsec); |
| // TODO(jsing) - potential deadlock! |
| // See above for details. |
| runtime·atomicstore(&m->waitsemalock, 0); |
| runtime·lwp_park(&ts, 0, &m->waitsemacount, nil); |
| } |
| // reacquire lock |
| while(runtime·xchg(&m->waitsemalock, 1)) |
| runtime·osyield(); |
| } |
| |
| // lock held (again) |
| if(m->waitsemacount != 0) { |
| // semaphore is available. |
| m->waitsemacount--; |
| // spin-mutex unlock |
| runtime·atomicstore(&m->waitsemalock, 0); |
| return 0; // semaphore acquired |
| } |
| |
| // semaphore not available. |
| // if there is a timeout, stop now. |
| // otherwise keep trying. |
| if(ns >= 0) |
| break; |
| } |
| |
| // lock held but giving up |
| // spin-mutex unlock |
| runtime·atomicstore(&m->waitsemalock, 0); |
| return -1; |
| } |
| |
| void |
| runtime·semawakeup(M *mp) |
| { |
| uint32 ret; |
| |
| // spin-mutex lock |
| while(runtime·xchg(&mp->waitsemalock, 1)) |
| runtime·osyield(); |
| mp->waitsemacount++; |
| // TODO(jsing) - potential deadlock, see semasleep() for details. |
| // Confirm that LWP is parked before unparking... |
| ret = runtime·lwp_unpark(mp->procid, &mp->waitsemacount); |
| if(ret != 0 && ret != ESRCH) |
| runtime·printf("thrwakeup addr=%p sem=%d ret=%d\n", &mp->waitsemacount, mp->waitsemacount, ret); |
| // spin-mutex unlock |
| runtime·atomicstore(&mp->waitsemalock, 0); |
| } |
| |
| void |
| runtime·newosproc(M *mp, void *stk) |
| { |
| UcontextT uc; |
| int32 ret; |
| |
| if(0) { |
| runtime·printf( |
| "newosproc stk=%p m=%p g=%p id=%d/%d ostk=%p\n", |
| stk, mp, mp->g0, mp->id, (int32)mp->tls[0], &mp); |
| } |
| |
| mp->tls[0] = mp->id; // so 386 asm can find it |
| |
| runtime·getcontext(&uc); |
| |
| uc.uc_flags = _UC_SIGMASK | _UC_CPU; |
| uc.uc_link = nil; |
| uc.uc_sigmask = sigset_all; |
| |
| runtime·lwp_mcontext_init(&uc.uc_mcontext, stk, mp, mp->g0, runtime·mstart); |
| |
| ret = runtime·lwp_create(&uc, 0, &mp->procid); |
| |
| if(ret < 0) { |
| runtime·printf("runtime: failed to create new OS thread (have %d already; errno=%d)\n", runtime·mcount() - 1, -ret); |
| runtime·throw("runtime.newosproc"); |
| } |
| } |
| |
| void |
| runtime·osinit(void) |
| { |
| runtime·ncpu = getncpu(); |
| } |
| |
| void |
| runtime·get_random_data(byte **rnd, int32 *rnd_len) |
| { |
| #pragma dataflag NOPTR |
| static byte urandom_data[HashRandomBytes]; |
| int32 fd; |
| fd = runtime·open("/dev/urandom", 0 /* O_RDONLY */, 0); |
| if(runtime·read(fd, urandom_data, HashRandomBytes) == HashRandomBytes) { |
| *rnd = urandom_data; |
| *rnd_len = HashRandomBytes; |
| } else { |
| *rnd = nil; |
| *rnd_len = 0; |
| } |
| runtime·close(fd); |
| } |
| |
| void |
| runtime·goenvs(void) |
| { |
| runtime·goenvs_unix(); |
| } |
| |
| // Called to initialize a new m (including the bootstrap m). |
| // Called on the parent thread (main thread in case of bootstrap), can allocate memory. |
| void |
| runtime·mpreinit(M *mp) |
| { |
| mp->gsignal = runtime·malg(32*1024); |
| } |
| |
| // Called to initialize a new m (including the bootstrap m). |
| // Called on the new thread, can not allocate memory. |
| void |
| runtime·minit(void) |
| { |
| m->procid = runtime·lwp_self(); |
| |
| // Initialize signal handling |
| runtime·signalstack((byte*)m->gsignal->stackguard - StackGuard, 32*1024); |
| runtime·sigprocmask(SIG_SETMASK, &sigset_none, nil); |
| } |
| |
| // Called from dropm to undo the effect of an minit. |
| void |
| runtime·unminit(void) |
| { |
| runtime·signalstack(nil, 0); |
| } |
| |
| void |
| runtime·sigpanic(void) |
| { |
| if(!runtime·canpanic(g)) |
| runtime·throw("unexpected signal during runtime execution"); |
| |
| switch(g->sig) { |
| case SIGBUS: |
| if(g->sigcode0 == BUS_ADRERR && g->sigcode1 < 0x1000 || g->paniconfault) { |
| if(g->sigpc == 0) |
| runtime·panicstring("call of nil func value"); |
| runtime·panicstring("invalid memory address or nil pointer dereference"); |
| } |
| runtime·printf("unexpected fault address %p\n", g->sigcode1); |
| runtime·throw("fault"); |
| case SIGSEGV: |
| if((g->sigcode0 == 0 || g->sigcode0 == SEGV_MAPERR || g->sigcode0 == SEGV_ACCERR) && g->sigcode1 < 0x1000 || g->paniconfault) { |
| if(g->sigpc == 0) |
| runtime·panicstring("call of nil func value"); |
| runtime·panicstring("invalid memory address or nil pointer dereference"); |
| } |
| runtime·printf("unexpected fault address %p\n", g->sigcode1); |
| runtime·throw("fault"); |
| case SIGFPE: |
| switch(g->sigcode0) { |
| case FPE_INTDIV: |
| runtime·panicstring("integer divide by zero"); |
| case FPE_INTOVF: |
| runtime·panicstring("integer overflow"); |
| } |
| runtime·panicstring("floating point error"); |
| } |
| runtime·panicstring(runtime·sigtab[g->sig].name); |
| } |
| |
| uintptr |
| runtime·memlimit(void) |
| { |
| return 0; |
| } |
| |
| extern void runtime·sigtramp(void); |
| |
| typedef struct sigaction { |
| union { |
| void (*_sa_handler)(int32); |
| void (*_sa_sigaction)(int32, Siginfo*, void *); |
| } _sa_u; /* signal handler */ |
| uint32 sa_mask[4]; /* signal mask to apply */ |
| int32 sa_flags; /* see signal options below */ |
| } Sigaction; |
| |
| void |
| runtime·setsig(int32 i, GoSighandler *fn, bool restart) |
| { |
| Sigaction sa; |
| |
| runtime·memclr((byte*)&sa, sizeof sa); |
| sa.sa_flags = SA_SIGINFO|SA_ONSTACK; |
| if(restart) |
| sa.sa_flags |= SA_RESTART; |
| sa.sa_mask[0] = ~0U; |
| sa.sa_mask[1] = ~0U; |
| sa.sa_mask[2] = ~0U; |
| sa.sa_mask[3] = ~0U; |
| if (fn == runtime·sighandler) |
| fn = (void*)runtime·sigtramp; |
| sa._sa_u._sa_sigaction = (void*)fn; |
| runtime·sigaction(i, &sa, nil); |
| } |
| |
| GoSighandler* |
| runtime·getsig(int32 i) |
| { |
| Sigaction sa; |
| |
| runtime·memclr((byte*)&sa, sizeof sa); |
| runtime·sigaction(i, nil, &sa); |
| if((void*)sa._sa_u._sa_sigaction == runtime·sigtramp) |
| return runtime·sighandler; |
| return (void*)sa._sa_u._sa_sigaction; |
| } |
| |
| void |
| runtime·signalstack(byte *p, int32 n) |
| { |
| StackT st; |
| |
| st.ss_sp = (void*)p; |
| st.ss_size = n; |
| st.ss_flags = 0; |
| if(p == nil) |
| st.ss_flags = SS_DISABLE; |
| runtime·sigaltstack(&st, nil); |
| } |
| |
| void |
| runtime·unblocksignals(void) |
| { |
| runtime·sigprocmask(SIG_SETMASK, &sigset_none, nil); |
| } |