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// 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 "stack.h"
extern SigTab runtime·sigtab[];
int32 runtime·open(uint8*, int32, int32);
int32 runtime·close(int32);
int32 runtime·read(int32, void*, int32);
// 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,
EINTR = 4,
EAGAIN = 11,
};
// Atomically,
// if(*addr == val) sleep
// Might be woken up spuriously; that's allowed.
// Don't sleep longer than ns; ns < 0 means forever.
void
runtime·futexsleep(uint32 *addr, uint32 val, int64 ns)
{
Timespec ts, *tsp;
if(ns < 0)
tsp = nil;
else {
ts.tv_sec = ns/1000000000LL;
ts.tv_nsec = ns%1000000000LL;
// Avoid overflow
if(ts.tv_sec > 1<<30)
ts.tv_sec = 1<<30;
tsp = &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.
runtime·futex(addr, FUTEX_WAIT, val, tsp, nil, 0);
}
// If any procs are sleeping on addr, wake up at most cnt.
void
runtime·futexwakeup(uint32 *addr, uint32 cnt)
{
int64 ret;
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.
runtime·printf("futexwakeup addr=%p returned %D\n", addr, ret);
*(int32*)0x1006 = 0x1006;
}
static int32
getproccount(void)
{
int32 fd, rd, cnt, cpustrlen;
byte *cpustr, *pos, *bufpos;
byte buf[256];
fd = runtime·open((byte*)"/proc/stat", O_RDONLY|O_CLOEXEC, 0);
if(fd == -1)
return 1;
cnt = 0;
bufpos = buf;
cpustr = (byte*)"\ncpu";
cpustrlen = runtime·findnull(cpustr);
for(;;) {
rd = runtime·read(fd, bufpos, sizeof(buf)-cpustrlen);
if(rd == -1)
break;
bufpos[rd] = 0;
for(pos=buf; pos=runtime·strstr(pos, cpustr); cnt++, pos++) {
}
if(rd < cpustrlen)
break;
runtime·memmove(buf, bufpos+rd-cpustrlen+1, cpustrlen-1);
bufpos = buf+cpustrlen-1;
}
runtime·close(fd);
return cnt ? cnt : 1;
}
// 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 *m, G *g, void *stk, void (*fn)(void))
{
int32 ret;
int32 flags;
/*
* 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 */
;
m->tls[0] = m->id; // so 386 asm can find it
if(0){
runtime·printf("newosproc stk=%p m=%p g=%p fn=%p clone=%p id=%d/%d ostk=%p\n",
stk, m, g, fn, runtime·clone, m->id, m->tls[0], &m);
}
if((ret = runtime·clone(flags, stk, m, g, fn)) < 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();
}
void
runtime·goenvs(void)
{
runtime·goenvs_unix();
}
// Called to initialize a new m (including the bootstrap m).
void
runtime·minit(void)
{
// Initialize signal handling.
m->gsignal = runtime·malg(32*1024); // OS X wants >=8K, Linux >=2K
runtime·signalstack(m->gsignal->stackguard - StackGuard, 32*1024);
}
void
runtime·sigpanic(void)
{
switch(g->sig) {
case SIGBUS:
if(g->sigcode0 == BUS_ADRERR && g->sigcode1 < 0x1000) {
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) {
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);
}
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