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Diffstat (limited to 'src/runtime/os_linux.c')
| -rw-r--r-- | src/runtime/os_linux.c | 362 |
1 files changed, 0 insertions, 362 deletions
diff --git a/src/runtime/os_linux.c b/src/runtime/os_linux.c deleted file mode 100644 index cc23774e3..000000000 --- a/src/runtime/os_linux.c +++ /dev/null @@ -1,362 +0,0 @@ -// Copyright 2009 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 "textflag.h" - -extern SigTab runtime·sigtab[]; - -static Sigset sigset_none; -static Sigset sigset_all = { ~(uint32)0, ~(uint32)0 }; - -// Linux futex. -// -// futexsleep(uint32 *addr, uint32 val) -// futexwakeup(uint32 *addr) -// -// Futexsleep atomically checks if *addr == val and if so, sleeps on addr. -// Futexwakeup wakes up threads sleeping on addr. -// Futexsleep is allowed to wake up spuriously. - -enum -{ - FUTEX_WAIT = 0, - FUTEX_WAKE = 1, -}; - -// Atomically, -// if(*addr == val) sleep -// Might be woken up spuriously; that's allowed. -// Don't sleep longer than ns; ns < 0 means forever. -#pragma textflag NOSPLIT -void -runtime·futexsleep(uint32 *addr, uint32 val, int64 ns) -{ - Timespec ts; - - // Some Linux kernels have a bug where futex of - // FUTEX_WAIT returns an internal error code - // as an errno. Libpthread ignores the return value - // here, and so can we: as it says a few lines up, - // spurious wakeups are allowed. - - if(ns < 0) { - runtime·futex(addr, FUTEX_WAIT, val, nil, nil, 0); - return; - } - - // It's difficult to live within the no-split stack limits here. - // On ARM and 386, a 64-bit divide invokes a general software routine - // that needs more stack than we can afford. So we use timediv instead. - // But on real 64-bit systems, where words are larger but the stack limit - // is not, even timediv is too heavy, and we really need to use just an - // ordinary machine instruction. - // Sorry for the #ifdef. - // For what it's worth, the #ifdef eliminated an implicit little-endian assumption. -#ifdef _64BIT - ts.tv_sec = ns / 1000000000LL; - ts.tv_nsec = ns % 1000000000LL; -#else - ts.tv_nsec = 0; - ts.tv_sec = runtime·timediv(ns, 1000000000LL, (int32*)&ts.tv_nsec); -#endif - runtime·futex(addr, FUTEX_WAIT, val, &ts, nil, 0); -} - -static void badfutexwakeup(void); - -// If any procs are sleeping on addr, wake up at most cnt. -#pragma textflag NOSPLIT -void -runtime·futexwakeup(uint32 *addr, uint32 cnt) -{ - int64 ret; - void (*fn)(void); - - ret = runtime·futex(addr, FUTEX_WAKE, cnt, nil, nil, 0); - if(ret >= 0) - return; - - // I don't know that futex wakeup can return - // EAGAIN or EINTR, but if it does, it would be - // safe to loop and call futex again. - g->m->ptrarg[0] = addr; - g->m->scalararg[0] = (int32)ret; // truncated but fine - fn = badfutexwakeup; - if(g == g->m->gsignal) - fn(); - else - runtime·onM(&fn); - *(int32*)0x1006 = 0x1006; -} - -static void -badfutexwakeup(void) -{ - void *addr; - int64 ret; - - addr = g->m->ptrarg[0]; - ret = (int32)g->m->scalararg[0]; - runtime·printf("futexwakeup addr=%p returned %D\n", addr, ret); -} - -extern runtime·sched_getaffinity(uintptr pid, uintptr len, uintptr *buf); -static int32 -getproccount(void) -{ - uintptr buf[16], t; - int32 r, n, i; - - r = runtime·sched_getaffinity(0, sizeof(buf), buf); - if(r <= 0) - return 1; - n = 0; - for(i = 0; i < r/sizeof(buf[0]); i++) { - t = buf[i]; - while(t != 0) { - n += t&1; - t >>= 1; - } - } - if(n < 1) - n = 1; - return n; -} - -// Clone, the Linux rfork. -enum -{ - CLONE_VM = 0x100, - CLONE_FS = 0x200, - CLONE_FILES = 0x400, - CLONE_SIGHAND = 0x800, - CLONE_PTRACE = 0x2000, - CLONE_VFORK = 0x4000, - CLONE_PARENT = 0x8000, - CLONE_THREAD = 0x10000, - CLONE_NEWNS = 0x20000, - CLONE_SYSVSEM = 0x40000, - CLONE_SETTLS = 0x80000, - CLONE_PARENT_SETTID = 0x100000, - CLONE_CHILD_CLEARTID = 0x200000, - CLONE_UNTRACED = 0x800000, - CLONE_CHILD_SETTID = 0x1000000, - CLONE_STOPPED = 0x2000000, - CLONE_NEWUTS = 0x4000000, - CLONE_NEWIPC = 0x8000000, -}; - -void -runtime·newosproc(M *mp, void *stk) -{ - int32 ret; - int32 flags; - Sigset oset; - - /* - * note: strace gets confused if we use CLONE_PTRACE here. - */ - flags = CLONE_VM /* share memory */ - | CLONE_FS /* share cwd, etc */ - | CLONE_FILES /* share fd table */ - | CLONE_SIGHAND /* share sig handler table */ - | CLONE_THREAD /* revisit - okay for now */ - ; - - mp->tls[0] = mp->id; // so 386 asm can find it - if(0){ - runtime·printf("newosproc stk=%p m=%p g=%p clone=%p id=%d/%d ostk=%p\n", - stk, mp, mp->g0, runtime·clone, mp->id, (int32)mp->tls[0], &mp); - } - - // Disable signals during clone, so that the new thread starts - // with signals disabled. It will enable them in minit. - runtime·rtsigprocmask(SIG_SETMASK, &sigset_all, &oset, sizeof oset); - ret = runtime·clone(flags, stk, mp, mp->g0, runtime·mstart); - runtime·rtsigprocmask(SIG_SETMASK, &oset, nil, sizeof oset); - - if(ret < 0) { - runtime·printf("runtime: failed to create new OS thread (have %d already; errno=%d)\n", runtime·mcount(), -ret); - runtime·throw("runtime.newosproc"); - } -} - -void -runtime·osinit(void) -{ - runtime·ncpu = getproccount(); -} - -// Random bytes initialized at startup. These come -// from the ELF AT_RANDOM auxiliary vector (vdso_linux_amd64.c). -byte* runtime·startup_random_data; -uint32 runtime·startup_random_data_len; - -#pragma textflag NOSPLIT -void -runtime·get_random_data(byte **rnd, int32 *rnd_len) -{ - if(runtime·startup_random_data != nil) { - *rnd = runtime·startup_random_data; - *rnd_len = runtime·startup_random_data_len; - } else { - #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); // OS X wants >=8K, Linux >=2K - runtime·writebarrierptr_nostore(&mp->gsignal, mp->gsignal); - - mp->gsignal->m = mp; - runtime·writebarrierptr_nostore(&mp->gsignal->m, mp->gsignal->m); -} - -// Called to initialize a new m (including the bootstrap m). -// Called on the new thread, can not allocate memory. -void -runtime·minit(void) -{ - // Initialize signal handling. - runtime·signalstack((byte*)g->m->gsignal->stack.lo, 32*1024); - runtime·rtsigprocmask(SIG_SETMASK, &sigset_none, nil, sizeof(Sigset)); -} - -// Called from dropm to undo the effect of an minit. -void -runtime·unminit(void) -{ - runtime·signalstack(nil, 0); -} - -uintptr -runtime·memlimit(void) -{ - Rlimit rl; - extern byte runtime·text[], runtime·end[]; - uintptr used; - - if(runtime·getrlimit(RLIMIT_AS, &rl) != 0) - return 0; - if(rl.rlim_cur >= 0x7fffffff) - return 0; - - // Estimate our VM footprint excluding the heap. - // Not an exact science: use size of binary plus - // some room for thread stacks. - used = runtime·end - runtime·text + (64<<20); - if(used >= rl.rlim_cur) - return 0; - - // If there's not at least 16 MB left, we're probably - // not going to be able to do much. Treat as no limit. - rl.rlim_cur -= used; - if(rl.rlim_cur < (16<<20)) - return 0; - - return rl.rlim_cur - used; -} - -#ifdef GOARCH_386 -#define sa_handler k_sa_handler -#endif - -/* - * This assembler routine takes the args from registers, puts them on the stack, - * and calls sighandler(). - */ -extern void runtime·sigtramp(void); -extern void runtime·sigreturn(void); // calls rt_sigreturn, only used with SA_RESTORER - -void -runtime·setsig(int32 i, GoSighandler *fn, bool restart) -{ - SigactionT sa; - - runtime·memclr((byte*)&sa, sizeof sa); - sa.sa_flags = SA_ONSTACK | SA_SIGINFO | SA_RESTORER; - if(restart) - sa.sa_flags |= SA_RESTART; - sa.sa_mask = ~0ULL; - // Although Linux manpage says "sa_restorer element is obsolete and - // should not be used". x86_64 kernel requires it. Only use it on - // x86. -#ifdef GOARCH_386 - sa.sa_restorer = (void*)runtime·sigreturn; -#endif -#ifdef GOARCH_amd64 - sa.sa_restorer = (void*)runtime·sigreturn; -#endif - if(fn == runtime·sighandler) - fn = (void*)runtime·sigtramp; - sa.sa_handler = fn; - // Qemu rejects rt_sigaction of SIGRTMAX (64). - if(runtime·rt_sigaction(i, &sa, nil, sizeof(sa.sa_mask)) != 0 && i != 64) - runtime·throw("rt_sigaction failure"); -} - -GoSighandler* -runtime·getsig(int32 i) -{ - SigactionT sa; - - runtime·memclr((byte*)&sa, sizeof sa); - if(runtime·rt_sigaction(i, nil, &sa, sizeof(sa.sa_mask)) != 0) - runtime·throw("rt_sigaction read failure"); - if((void*)sa.sa_handler == runtime·sigtramp) - return runtime·sighandler; - return (void*)sa.sa_handler; -} - -void -runtime·signalstack(byte *p, int32 n) -{ - SigaltstackT st; - - st.ss_sp = 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·rtsigprocmask(SIG_SETMASK, &sigset_none, nil, sizeof sigset_none); -} - -#pragma textflag NOSPLIT -int8* -runtime·signame(int32 sig) -{ - return runtime·sigtab[sig].name; -} |