[dev.cc] runtime: convert operating system support code from C to Go

The conversion was done with an automated tool and then
modified only as necessary to make it compile and run.

[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]

LGTM=r
R=r
CC=austin, dvyukov, golang-codereviews, iant, khr
https://golang.org/cl/174830044

src/runtime/alg.go

@@ -314,9 +314,6 @@ const hashRandomBytes = 32
 
 var aeskeysched [hashRandomBytes]byte
 
-//go:noescape
-func get_random_data(rnd *unsafe.Pointer, n *int32)
-
 func init() {
 	if theGoos == "nacl" {
 		return

src/runtime/os1_linux.go

+// 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.
+
+package runtime
+
+import "unsafe"
+
+var sigset_none sigset
+var sigset_all sigset = sigset{^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.
+
+const (
+	_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.
+//go:nosplit
+func futexsleep(addr *uint32, val uint32, ns int64) {
+	var ts timespec
+
+	// 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 {
+		futex(unsafe.Pointer(addr), _FUTEX_WAIT, val, nil, nil, 0)
+		return
+	}
+
+	// NOTE: tv_nsec is int64 on amd64, so this assumes a little-endian system.
+	ts.tv_nsec = 0
+	ts.set_sec(timediv(ns, 1000000000, (*int32)(unsafe.Pointer(&ts.tv_nsec))))
+	futex(unsafe.Pointer(addr), _FUTEX_WAIT, val, unsafe.Pointer(&ts), nil, 0)
+}
+
+// If any procs are sleeping on addr, wake up at most cnt.
+//go:nosplit
+func futexwakeup(addr *uint32, cnt uint32) {
+	ret := futex(unsafe.Pointer(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.
+	onM_signalok(func() {
+		print("futexwakeup addr=", addr, " returned ", ret, "\n")
+	})
+
+	*(*int32)(unsafe.Pointer(uintptr(0x1006))) = 0x1006
+}
+
+func getproccount() int32 {
+	var buf [16]uintptr
+	r := sched_getaffinity(0, unsafe.Sizeof(buf), &buf[0])
+	n := int32(0)
+	for _, v := range buf[:r/ptrSize] {
+		for i := 0; i < 64; i++ {
+			n += int32(v & 1)
+			v >>= 1
+		}
+	}
+	if n == 0 {
+		n = 1
+	}
+	return n
+}
+
+// Clone, the Linux rfork.
+const (
+	_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
+)
+
+func newosproc(mp *m, stk unsafe.Pointer) {
+	/*
+	 * note: strace gets confused if we use CLONE_PTRACE here.
+	 */
+	var flags int32 = _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] = uintptr(mp.id) // so 386 asm can find it
+	if false {
+		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " clone=", funcPC(clone), " id=", mp.id, "/", mp.tls[0], " ostk=", &mp, "\n")
+	}
+
+	// Disable signals during clone, so that the new thread starts
+	// with signals disabled.  It will enable them in minit.
+	var oset sigset
+	rtsigprocmask(_SIG_SETMASK, &sigset_all, &oset, int32(unsafe.Sizeof(oset)))
+	ret := clone(flags, stk, unsafe.Pointer(mp), unsafe.Pointer(mp.g0), unsafe.Pointer(funcPC(mstart)))
+	rtsigprocmask(_SIG_SETMASK, &oset, nil, int32(unsafe.Sizeof(oset)))
+
+	if ret < 0 {
+		print("runtime: failed to create new OS thread (have ", mcount(), " already; errno=", -ret, ")\n")
+		gothrow("newosproc")
+	}
+}
+
+func osinit() {
+	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;
+
+var urandom_data [_HashRandomBytes]byte
+var urandom_dev = []byte("/dev/random\x00")
+
+//go:nosplit
+func get_random_data(rnd *unsafe.Pointer, rnd_len *int32) {
+	if startup_random_data != nil {
+		*rnd = unsafe.Pointer(startup_random_data)
+		*rnd_len = int32(startup_random_data_len)
+		return
+	}
+	fd := open(&urandom_dev[0], 0 /* O_RDONLY */, 0)
+	if read(fd, unsafe.Pointer(&urandom_data), _HashRandomBytes) == _HashRandomBytes {
+		*rnd = unsafe.Pointer(&urandom_data[0])
+		*rnd_len = _HashRandomBytes
+	} else {
+		*rnd = nil
+		*rnd_len = 0
+	}
+	close(fd)
+}
+
+func goenvs() {
+	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.
+func mpreinit(mp *m) {
+	mp.gsignal = malg(32 * 1024) // Linux wants >= 2K
+	mp.gsignal.m = mp
+}
+
+// Called to initialize a new m (including the bootstrap m).
+// Called on the new thread, can not allocate memory.
+func minit() {
+	// Initialize signal handling.
+	_g_ := getg()
+	signalstack((*byte)(unsafe.Pointer(_g_.m.gsignal.stack.lo)), 32*1024)
+	rtsigprocmask(_SIG_SETMASK, &sigset_none, nil, int32(unsafe.Sizeof(sigset_none)))
+}
+
+// Called from dropm to undo the effect of an minit.
+func unminit() {
+	signalstack(nil, 0)
+}
+
+func memlimit() uintptr {
+	/*
+		TODO: Convert to Go when something actually uses the result.
+
+		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;
+	*/
+
+	return 0
+}
+
+//#ifdef GOARCH_386
+//#define sa_handler k_sa_handler
+//#endif
+
+func sigreturn()
+func sigtramp()
+
+func setsig(i int32, fn uintptr, restart bool) {
+	var sa sigactiont
+	memclr(unsafe.Pointer(&sa), unsafe.Sizeof(sa))
+	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTORER
+	if restart {
+		sa.sa_flags |= _SA_RESTART
+	}
+	sa.sa_mask = ^uint64(0)
+	// Although Linux manpage says "sa_restorer element is obsolete and
+	// should not be used". x86_64 kernel requires it. Only use it on
+	// x86.
+	if GOARCH == "386" || GOARCH == "amd64" {
+		sa.sa_restorer = funcPC(sigreturn)
+	}
+	if fn == funcPC(sighandler) {
+		fn = funcPC(sigtramp)
+	}
+	sa.sa_handler = fn
+	if rt_sigaction(uintptr(i), &sa, nil, unsafe.Sizeof(sa.sa_mask)) != 0 {
+		gothrow("rt_sigaction failure")
+	}
+}
+
+func getsig(i int32) uintptr {
+	var sa sigactiont
+
+	memclr(unsafe.Pointer(&sa), unsafe.Sizeof(sa))
+	if rt_sigaction(uintptr(i), nil, &sa, unsafe.Sizeof(sa.sa_mask)) != 0 {
+		gothrow("rt_sigaction read failure")
+	}
+	if sa.sa_handler == funcPC(sigtramp) {
+		return funcPC(sighandler)
+	}
+	return sa.sa_handler
+}
+
+func signalstack(p *byte, n int32) {
+	var st sigaltstackt
+	st.ss_sp = p
+	st.ss_size = uintptr(n)
+	st.ss_flags = 0
+	if p == nil {
+		st.ss_flags = _SS_DISABLE
+	}
+	sigaltstack(&st, nil)
+}
+
+func unblocksignals() {
+	rtsigprocmask(_SIG_SETMASK, &sigset_none, nil, int32(unsafe.Sizeof(sigset_none)))
+}

src/runtime/os2_darwin.go

+// 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.
+
+package runtime
+
+const (
+	_NSIG        = 32
+	_SI_USER     = 0 /* empirically true, but not what headers say */
+	_SIG_BLOCK   = 1
+	_SIG_UNBLOCK = 2
+	_SIG_SETMASK = 3
+	_SS_DISABLE  = 4
+)

src/runtime/os2_linux.go

+// 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.
+
+package runtime
+
+const (
+	_SS_DISABLE  = 2
+	_NSIG        = 65
+	_SI_USER     = 0
+	_SIG_SETMASK = 2
+	_RLIMIT_AS   = 9
+)
+
+// It's hard to tease out exactly how big a Sigset is, but
+// rt_sigprocmask crashes if we get it wrong, so if binaries
+// are running, this is right.
+type sigset [2]uint32
+
+type rlimit struct {
+	rlim_cur uintptr
+	rlim_max uintptr
+}

src/runtime/os_darwin.go

@@ -6,19 +6,35 @@ package runtime
 
 import "unsafe"
 
-func bsdthread_create(stk, mm, gg, fn unsafe.Pointer) int32
+func bsdthread_create(stk unsafe.Pointer, mm *m, gg *g, fn uintptr) int32
 func bsdthread_register() int32
+
+//go:noescape
 func mach_msg_trap(h unsafe.Pointer, op int32, send_size, rcv_size, rcv_name, timeout, notify uint32) int32
+
 func mach_reply_port() uint32
 func mach_task_self() uint32
 func mach_thread_self() uint32
+
+//go:noescape
 func sysctl(mib *uint32, miblen uint32, out *byte, size *uintptr, dst *byte, ndst uintptr) int32
-func sigprocmask(sig int32, new, old unsafe.Pointer)
-func sigaction(mode uint32, new, old unsafe.Pointer)
-func sigaltstack(new, old unsafe.Pointer)
+
+//go:noescape
+func sigprocmask(sig uint32, new, old *uint32)
+
+//go:noescape
+func sigaction(mode uint32, new, old *sigactiont)
+
+//go:noescape
+func sigaltstack(new, old *stackt)
+
 func sigtramp()
-func setitimer(mode int32, new, old unsafe.Pointer)
-func mach_semaphore_wait(sema uint32) int32
-func mach_semaphore_timedwait(sema, sec, nsec uint32) int32
-func mach_semaphore_signal(sema uint32) int32
-func mach_semaphore_signal_all(sema uint32) int32
+
+//go:noescape
+func setitimer(mode int32, new, old *itimerval)
+
+func raise(int32)
+
+// careful: cputicks is not guaranteed to be monotonic!  In particular, we have
+// noticed drift between cpus on certain os/arch combinations.  See issue 8976.
+func cputicks() int64

src/runtime/os_darwin.h

-// 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.
-
-typedef byte* kevent_udata;
-
-int32	runtime·bsdthread_create(void*, M*, G*, void(*)(void));
-int32	runtime·bsdthread_register(void);
-int32	runtime·mach_msg_trap(MachHeader*, int32, uint32, uint32, uint32, uint32, uint32);
-uint32	runtime·mach_reply_port(void);
-int32	runtime·mach_semacquire(uint32, int64);
-uint32	runtime·mach_semcreate(void);
-void	runtime·mach_semdestroy(uint32);
-void	runtime·mach_semrelease(uint32);
-void	runtime·mach_semreset(uint32);
-uint32	runtime·mach_task_self(void);
-uint32	runtime·mach_task_self(void);
-uint32	runtime·mach_thread_self(void);
-uint32	runtime·mach_thread_self(void);
-int32	runtime·sysctl(uint32*, uint32, byte*, uintptr*, byte*, uintptr);
-
-typedef uint32 Sigset;
-void	runtime·sigprocmask(int32, Sigset*, Sigset*);
-void	runtime·unblocksignals(void);
-
-struct SigactionT;
-void	runtime·sigaction(uintptr, struct SigactionT*, struct SigactionT*);
-
-struct StackT;
-void	runtime·sigaltstack(struct StackT*, struct StackT*);
-void	runtime·sigtramp(void);
-void	runtime·sigpanic(void);
-void	runtime·setitimer(int32, Itimerval*, Itimerval*);
-
-
-enum {
-	NSIG = 32,
-	SI_USER = 0, /* empirically true, but not what headers say */
-	SIG_BLOCK = 1,
-	SIG_UNBLOCK = 2,
-	SIG_SETMASK = 3,
-	SS_DISABLE = 4,
-};

src/runtime/os_dragonfly.c

@@ -9,7 +9,7 @@
 #include "stack.h"
 #include "textflag.h"
 
-extern SigTab runtime·sigtab[];
+extern SigTabT runtime·sigtab[];
 extern int32 runtime·sys_umtx_sleep(uint32*, int32, int32);
 extern int32 runtime·sys_umtx_wakeup(uint32*, int32);
 

src/runtime/os_freebsd.c

@@ -9,7 +9,7 @@
 #include "stack.h"
 #include "textflag.h"
 
-extern SigTab runtime·sigtab[];
+extern SigTabT runtime·sigtab[];
 extern int32 runtime·sys_umtx_op(uint32*, int32, uint32, void*, void*);
 
 // From FreeBSD's <sys/sysctl.h>

src/runtime/os_linux.c

-// 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;
-	}
-	// NOTE: tv_nsec is int64 on amd64, so this assumes a little-endian system.
-	ts.tv_nsec = 0;
-	ts.tv_sec = runtime·timediv(ns, 1000000000LL, (int32*)&ts.tv_nsec);
-	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, cnt, i;
-
-	cnt = 0;
-	r = runtime·sched_getaffinity(0, sizeof(buf), buf);
-	if(r > 0)
-	for(i = 0; i < r/sizeof(buf[0]); i++) {
-		t = buf[i];
-		t = t - ((t >> 1) & 0x5555555555555555ULL);
-		t = (t & 0x3333333333333333ULL) + ((t >> 2) & 0x3333333333333333ULL);
-		cnt += (int32)((((t + (t >> 4)) & 0xF0F0F0F0F0F0F0FULL) * 0x101010101010101ULL) >> 56);
-	}
-
-	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 *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
-	mp->gsignal->m = mp;
-}
-
-// 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;
-	if(runtime·rt_sigaction(i, &sa, nil, sizeof(sa.sa_mask)) != 0)
-		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;
-}

src/runtime/os_linux.go

@@ -6,12 +6,28 @@ package runtime
 
 import "unsafe"
 
+//go:noescape
 func futex(addr unsafe.Pointer, op int32, val uint32, ts, addr2 unsafe.Pointer, val3 uint32) int32
+
+//go:noescape
 func clone(flags int32, stk, mm, gg, fn unsafe.Pointer) int32
-func rt_sigaction(sig uintptr, new, old unsafe.Pointer, size uintptr) int32
-func sigaltstack(new, old unsafe.Pointer)
-func setitimer(mode int32, new, old unsafe.Pointer)
-func rtsigprocmask(sig int32, new, old unsafe.Pointer, size int32)
+
+//go:noescape
+func rt_sigaction(sig uintptr, new, old *sigactiont, size uintptr) int32
+
+//go:noescape
+func sigaltstack(new, old *sigaltstackt)
+
+//go:noescape
+func setitimer(mode int32, new, old *itimerval)
+
+//go:noescape
+func rtsigprocmask(sig uint32, new, old *sigset, size int32)
+
+//go:noescape
 func getrlimit(kind int32, limit unsafe.Pointer) int32
-func raise(sig int32)
+func raise(sig uint32)
+
+//go:noescape
 func sched_getaffinity(pid, len uintptr, buf *uintptr) int32
+func osyield()

src/runtime/os_linux.h

-// 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.
-
-
-// Linux-specific system calls
-int32	runtime·futex(uint32*, int32, uint32, Timespec*, uint32*, uint32);
-int32	runtime·clone(int32, void*, M*, G*, void(*)(void));
-
-struct SigactionT;
-int32	runtime·rt_sigaction(uintptr, struct SigactionT*, void*, uintptr);
-
-void	runtime·sigaltstack(SigaltstackT*, SigaltstackT*);
-void	runtime·sigpanic(void);
-void runtime·setitimer(int32, Itimerval*, Itimerval*);
-
-enum {
-	SS_DISABLE = 2,
-	NSIG = 65,
-	SI_USER = 0,
-	SIG_SETMASK = 2,
-	RLIMIT_AS = 9,
-};
-
-// It's hard to tease out exactly how big a Sigset is, but
-// rt_sigprocmask crashes if we get it wrong, so if binaries
-// are running, this is right.
-typedef struct Sigset Sigset;
-struct Sigset
-{
-	uint32 mask[2];
-};
-void	runtime·rtsigprocmask(int32, Sigset*, Sigset*, int32);
-void	runtime·unblocksignals(void);
-
-typedef struct Rlimit Rlimit;
-struct Rlimit {
-	uintptr	rlim_cur;
-	uintptr	rlim_max;
-};
-int32	runtime·getrlimit(int32, Rlimit*);

src/runtime/os_linux_386.c

-// 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 "textflag.h"
-
-#define AT_NULL		0
-#define AT_RANDOM	25
-#define AT_SYSINFO	32
-extern uint32 runtime·_vdso;
-
-#pragma textflag NOSPLIT
-void
-runtime·linux_setup_vdso(int32 argc, byte **argv)
-{
-	byte **envp;
-	uint32 *auxv;
-
-	// skip envp to get to ELF auxiliary vector.
-	for(envp = &argv[argc+1]; *envp != nil; envp++)
-		;
-	envp++;
-	
-	for(auxv=(uint32*)envp; auxv[0] != AT_NULL; auxv += 2) {
-		if(auxv[0] == AT_SYSINFO) {
-			runtime·_vdso = auxv[1];
-			continue;
-		}
-		if(auxv[0] == AT_RANDOM) {
-			runtime·startup_random_data = (byte*)auxv[1];
-			runtime·startup_random_data_len = 16;
-			continue;
-		}
-	}
-}

src/runtime/os_linux_386.go

+// 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.
+
+package runtime
+
+import "unsafe"
+
+const (
+	_AT_NULL    = 0
+	_AT_RANDOM  = 25
+	_AT_SYSINFO = 32
+)
+
+var _vdso uint32
+
+//go:nosplit
+func linux_setup_vdso(argc int32, argv **byte) {
+	// skip over argv, envv to get to auxv
+	n := argc + 1
+	for argv_index(argv, n) != nil {
+		n++
+	}
+	n++
+	auxv := (*[1 << 28]uint32)(add(unsafe.Pointer(argv), uintptr(n)*ptrSize))
+
+	for i := 0; auxv[i] != _AT_NULL; i += 2 {
+		switch auxv[i] {
+		case _AT_SYSINFO:
+			_vdso = auxv[i+1]
+
+		case _AT_RANDOM:
+			startup_random_data = (*byte)(unsafe.Pointer(uintptr(auxv[i+1])))
+			startup_random_data_len = 16
+		}
+	}
+}
+
+// careful: cputicks is not guaranteed to be monotonic!  In particular, we have
+// noticed drift between cpus on certain os/arch combinations.  See issue 8976.
+func cputicks() int64

src/runtime/os_linux_amd64.go

+// Copyright 2014 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.
+
+package runtime
+
+// careful: cputicks is not guaranteed to be monotonic!  In particular, we have
+// noticed drift between cpus on certain os/arch combinations.  See issue 8976.
+func cputicks() int64

src/runtime/os_linux_arm.c

-// 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 "textflag.h"
-
-#define AT_NULL		0
-#define AT_PLATFORM	15 // introduced in at least 2.6.11
-#define AT_HWCAP	16 // introduced in at least 2.6.11
-#define AT_RANDOM	25 // introduced in 2.6.29
-#define HWCAP_VFP	(1 << 6) // introduced in at least 2.6.11
-#define HWCAP_VFPv3	(1 << 13) // introduced in 2.6.30
-static uint32 runtime·randomNumber;
-uint8  runtime·armArch = 6;	// we default to ARMv6
-uint32 runtime·hwcap;	// set by setup_auxv
-extern uint8  runtime·goarm;	// set by 5l
-
-void
-runtime·checkgoarm(void)
-{
-	if(runtime·goarm > 5 && !(runtime·hwcap & HWCAP_VFP)) {
-		runtime·printf("runtime: this CPU has no floating point hardware, so it cannot run\n");
-		runtime·printf("this GOARM=%d binary. Recompile using GOARM=5.\n", runtime·goarm);
-		runtime·exit(1);
-	}
-	if(runtime·goarm > 6 && !(runtime·hwcap & HWCAP_VFPv3)) {
-		runtime·printf("runtime: this CPU has no VFPv3 floating point hardware, so it cannot run\n");
-		runtime·printf("this GOARM=%d binary. Recompile using GOARM=6.\n", runtime·goarm);
-		runtime·exit(1);
-	}
-}
-
-#pragma textflag NOSPLIT
-void
-runtime·setup_auxv(int32 argc, byte **argv)
-{
-	byte **envp;
-	byte *rnd;
-	uint32 *auxv;
-	uint32 t;
-
-	// skip envp to get to ELF auxiliary vector.
-	for(envp = &argv[argc+1]; *envp != nil; envp++)
-		;
-	envp++;
-	
-	for(auxv=(uint32*)envp; auxv[0] != AT_NULL; auxv += 2) {
-		switch(auxv[0]) {
-		case AT_RANDOM: // kernel provided 16-byte worth of random data
-			if(auxv[1]) {
-				rnd = (byte*)auxv[1];
-				runtime·randomNumber = rnd[4] | rnd[5]<<8 | rnd[6]<<16 | rnd[7]<<24;
-			}
-			break;
-		case AT_PLATFORM: // v5l, v6l, v7l
-			if(auxv[1]) {
-				t = *(uint8*)(auxv[1]+1);
-				if(t >= '5' && t <= '7')
-					runtime·armArch = t - '0';
-			}
-			break;
-		case AT_HWCAP: // CPU capability bit flags
-			runtime·hwcap = auxv[1];
-			break;
-		}
-	}
-}
-
-#pragma textflag NOSPLIT
-int64
-runtime·cputicks(void)
-{
-	// Currently cputicks() is used in blocking profiler and to seed runtime·fastrand1().
-	// runtime·nanotime() is a poor approximation of CPU ticks that is enough for the profiler.
-	// runtime·randomNumber provides better seeding of fastrand1.
-	return runtime·nanotime() + runtime·randomNumber;
-}

src/runtime/os_linux_arm.go

+// 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.
+
+// 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.
+
+package runtime
+
+import "unsafe"
+
+const (
+	_AT_NULL     = 0
+	_AT_PLATFORM = 15 //  introduced in at least 2.6.11
+	_AT_HWCAP    = 16 // introduced in at least 2.6.11
+	_AT_RANDOM   = 25 // introduced in 2.6.29
+
+	_HWCAP_VFP   = 1 << 6  // introduced in at least 2.6.11
+	_HWCAP_VFPv3 = 1 << 13 // introduced in 2.6.30
+)
+
+var randomNumber uint32
+var armArch uint8 = 6 // we default to ARMv6
+var hwcap uint32      // set by setup_auxv
+var goarm uint8       // set by 5l
+
+func checkgoarm() {
+	if goarm > 5 && hwcap&_HWCAP_VFP == 0 {
+		print("runtime: this CPU has no floating point hardware, so it cannot run\n")
+		print("this GOARM=", goarm, " binary. Recompile using GOARM=5.\n")
+		exit(1)
+	}
+	if goarm > 6 && hwcap&_HWCAP_VFPv3 == 0 {
+		print("runtime: this CPU has no VFPv3 floating point hardware, so it cannot run\n")
+		print("this GOARM=", goarm, " binary. Recompile using GOARM=5.\n")
+		exit(1)
+	}
+}
+
+//go:nosplit
+func setup_auxv(argc int32, argv **byte) {
+	// skip over argv, envv to get to auxv
+	n := argc + 1
+	for argv_index(argv, n) != nil {
+		n++
+	}
+	n++
+	auxv := (*[1 << 28]uint32)(add(unsafe.Pointer(argv), uintptr(n)*ptrSize))
+
+	for i := 0; auxv[i] != _AT_NULL; i += 2 {
+		switch auxv[i] {
+		case _AT_RANDOM: // kernel provided 16-byte worth of random data
+			if auxv[i+1] != 0 {
+				randomNumber = *(*uint32)(unsafe.Pointer(uintptr(auxv[i+1])))
+			}
+
+		case _AT_PLATFORM: // v5l, v6l, v7l
+			t := *(*uint8)(unsafe.Pointer(uintptr(auxv[i+1] + 1)))
+			if '5' <= t && t <= '7' {
+				armArch = t - '0'
+			}
+
+		case _AT_HWCAP: // CPU capability bit flags
+			hwcap = auxv[i+1]
+		}
+	}
+}
+
+func cputicks() int64 {
+	// Currently cputicks() is used in blocking profiler and to seed fastrand1().
+	// nanotime() is a poor approximation of CPU ticks that is enough for the profiler.
+	// randomNumber provides better seeding of fastrand1.
+	return nanotime() + int64(randomNumber)
+}

src/runtime/vdso_linux_amd64.go

+// Copyright 2012 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.
+
+package runtime
+
+import "unsafe"
+
+// Look up symbols in the Linux vDSO.
+
+// This code was originally based on the sample Linux vDSO parser at
+// https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/vDSO/parse_vdso.c
+
+// This implements the ELF dynamic linking spec at
+// http://sco.com/developers/gabi/latest/ch5.dynamic.html
+
+// The version section is documented at
+// http://refspecs.linuxfoundation.org/LSB_3.2.0/LSB-Core-generic/LSB-Core-generic/symversion.html
+
+const (
+	_AT_RANDOM       = 25
+	_AT_SYSINFO_EHDR = 33
+	_AT_NULL         = 0 /* End of vector */
+
+	_PT_LOAD    = 1 /* Loadable program segment */
+	_PT_DYNAMIC = 2 /* Dynamic linking information */
+
+	_DT_NULL   = 0 /* Marks end of dynamic section */
+	_DT_HASH   = 4 /* Dynamic symbol hash table */
+	_DT_STRTAB = 5 /* Address of string table */
+	_DT_SYMTAB = 6 /* Address of symbol table */
+	_DT_VERSYM = 0x6ffffff0
+	_DT_VERDEF = 0x6ffffffc
+
+	_VER_FLG_BASE = 0x1 /* Version definition of file itself */
+
+	_SHN_UNDEF = 0 /* Undefined section */
+
+	_SHT_DYNSYM = 11 /* Dynamic linker symbol table */
+
+	_STT_FUNC = 2 /* Symbol is a code object */
+
+	_STB_GLOBAL = 1 /* Global symbol */
+	_STB_WEAK   = 2 /* Weak symbol */
+
+	_EI_NIDENT = 16
+)
+
+/* How to extract and insert information held in the st_info field.  */
+func _ELF64_ST_BIND(val byte) byte { return val >> 4 }
+func _ELF64_ST_TYPE(val byte) byte { return val & 0xf }
+
+type elf64Sym struct {
+	st_name  uint32
+	st_info  byte
+	st_other byte
+	st_shndx uint16
+	st_value uint64
+	st_size  uint64
+}
+
+type elf64Verdef struct {
+	vd_version uint16 /* Version revision */
+	vd_flags   uint16 /* Version information */
+	vd_ndx     uint16 /* Version Index */
+	vd_cnt     uint16 /* Number of associated aux entries */
+	vd_hash    uint32 /* Version name hash value */
+	vd_aux     uint32 /* Offset in bytes to verdaux array */
+	vd_next    uint32 /* Offset in bytes to next verdef entry */
+}
+
+type elf64Ehdr struct {
+	e_ident     [_EI_NIDENT]byte /* Magic number and other info */
+	e_type      uint16           /* Object file type */
+	e_machine   uint16           /* Architecture */
+	e_version   uint32           /* Object file version */
+	e_entry     uint64           /* Entry point virtual address */
+	e_phoff     uint64           /* Program header table file offset */
+	e_shoff     uint64           /* Section header table file offset */
+	e_flags     uint32           /* Processor-specific flags */
+	e_ehsize    uint16           /* ELF header size in bytes */
+	e_phentsize uint16           /* Program header table entry size */
+	e_phnum     uint16           /* Program header table entry count */
+	e_shentsize uint16           /* Section header table entry size */
+	e_shnum     uint16           /* Section header table entry count */
+	e_shstrndx  uint16           /* Section header string table index */
+}
+
+type elf64Phdr struct {
+	p_type   uint32 /* Segment type */
+	p_flags  uint32 /* Segment flags */
+	p_offset uint64 /* Segment file offset */
+	p_vaddr  uint64 /* Segment virtual address */
+	p_paddr  uint64 /* Segment physical address */
+	p_filesz uint64 /* Segment size in file */
+	p_memsz  uint64 /* Segment size in memory */
+	p_align  uint64 /* Segment alignment */
+}
+
+type elf64Shdr struct {
+	sh_name      uint32 /* Section name (string tbl index) */
+	sh_type      uint32 /* Section type */
+	sh_flags     uint64 /* Section flags */
+	sh_addr      uint64 /* Section virtual addr at execution */
+	sh_offset    uint64 /* Section file offset */
+	sh_size      uint64 /* Section size in bytes */
+	sh_link      uint32 /* Link to another section */
+	sh_info      uint32 /* Additional section information */
+	sh_addralign uint64 /* Section alignment */
+	sh_entsize   uint64 /* Entry size if section holds table */
+}
+
+type elf64Dyn struct {
+	d_tag int64  /* Dynamic entry type */
+	d_val uint64 /* Integer value */
+}
+
+type elf64Verdaux struct {
+	vda_name uint32 /* Version or dependency names */
+	vda_next uint32 /* Offset in bytes to next verdaux entry */
+}
+
+type elf64Auxv struct {
+	a_type uint64 /* Entry type */
+	a_val  uint64 /* Integer value */
+}
+
+type symbol_key struct {
+	name     string
+	sym_hash uint32
+	ptr      *uintptr
+}
+
+type version_key struct {
+	version  string
+	ver_hash uint32
+}
+
+type vdso_info struct {
+	valid bool
+
+	/* Load information */
+	load_addr   uintptr
+	load_offset uintptr /* load_addr - recorded vaddr */
+
+	/* Symbol table */
+	symtab     *[1 << 32]elf64Sym
+	symstrings *[1 << 32]byte
+	chain      []uint32
+	bucket     []uint32
+
+	/* Version table */
+	versym *[1 << 32]uint16
+	verdef *elf64Verdef
+}
+
+var linux26 = version_key{"LINUX_2.6", 0x3ae75f6}
+
+var sym_keys = []symbol_key{
+	{"__vdso_time", 0xa33c485, &__vdso_time_sym},
+	{"__vdso_gettimeofday", 0x315ca59, &__vdso_gettimeofday_sym},
+	{"__vdso_clock_gettime", 0xd35ec75, &__vdso_clock_gettime_sym},
+}
+
+// initialize with vsyscall fallbacks
+var (
+	__vdso_time_sym          uintptr = 0xffffffffff600400
+	__vdso_gettimeofday_sym  uintptr = 0xffffffffff600000
+	__vdso_clock_gettime_sym uintptr = 0
+)
+
+func vdso_init_from_sysinfo_ehdr(info *vdso_info, hdr *elf64Ehdr) {
+	info.valid = false
+	info.load_addr = uintptr(unsafe.Pointer(hdr))
+
+	pt := unsafe.Pointer(info.load_addr + uintptr(hdr.e_phoff))
+
+	// We need two things from the segment table: the load offset
+	// and the dynamic table.
+	var found_vaddr bool
+	var dyn *[1 << 20]elf64Dyn
+	for i := uint16(0); i < hdr.e_phnum; i++ {
+		pt := (*elf64Phdr)(add(pt, uintptr(i)*unsafe.Sizeof(elf64Phdr{})))
+		switch pt.p_type {
+		case _PT_LOAD:
+			if !found_vaddr {
+				found_vaddr = true
+				info.load_offset = info.load_addr + uintptr(pt.p_offset-pt.p_vaddr)
+			}
+
+		case _PT_DYNAMIC:
+			dyn = (*[1 << 20]elf64Dyn)(unsafe.Pointer(info.load_addr + uintptr(pt.p_offset)))
+		}
+	}
+
+	if !found_vaddr || dyn == nil {
+		return // Failed
+	}
+
+	// Fish out the useful bits of the dynamic table.
+
+	var hash *[1 << 30]uint32
+	hash = nil
+	info.symstrings = nil
+	info.symtab = nil
+	info.versym = nil
+	info.verdef = nil
+	for i := 0; dyn[i].d_tag != _DT_NULL; i++ {
+		dt := &dyn[i]
+		p := info.load_offset + uintptr(dt.d_val)
+		switch dt.d_tag {
+		case _DT_STRTAB:
+			info.symstrings = (*[1 << 32]byte)(unsafe.Pointer(p))
+		case _DT_SYMTAB:
+			info.symtab = (*[1 << 32]elf64Sym)(unsafe.Pointer(p))
+		case _DT_HASH:
+			hash = (*[1 << 30]uint32)(unsafe.Pointer(p))
+		case _DT_VERSYM:
+			info.versym = (*[1 << 32]uint16)(unsafe.Pointer(p))
+		case _DT_VERDEF:
+			info.verdef = (*elf64Verdef)(unsafe.Pointer(p))
+		}
+	}
+
+	if info.symstrings == nil || info.symtab == nil || hash == nil {
+		return // Failed
+	}
+
+	if info.verdef == nil {
+		info.versym = nil
+	}
+
+	// Parse the hash table header.
+	nbucket := hash[0]
+	nchain := hash[1]
+	info.bucket = hash[2 : 2+nbucket]
+	info.chain = hash[2+nbucket : 2+nbucket+nchain]
+
+	// That's all we need.
+	info.valid = true
+}
+
+func vdso_find_version(info *vdso_info, ver *version_key) int32 {
+	if !info.valid {
+		return 0
+	}
+
+	def := info.verdef
+	for {
+		if def.vd_flags&_VER_FLG_BASE == 0 {
+			aux := (*elf64Verdaux)(add(unsafe.Pointer(def), uintptr(def.vd_aux)))
+			if def.vd_hash == ver.ver_hash && ver.version == gostringnocopy(&info.symstrings[aux.vda_name]) {
+				return int32(def.vd_ndx & 0x7fff)
+			}
+		}
+
+		if def.vd_next == 0 {
+			break
+		}
+		def = (*elf64Verdef)(add(unsafe.Pointer(def), uintptr(def.vd_next)))
+	}
+
+	return -1 // can not match any version
+}
+
+func vdso_parse_symbols(info *vdso_info, version int32) {
+	if !info.valid {
+		return
+	}
+
+	for _, k := range sym_keys {
+		for chain := info.bucket[k.sym_hash%uint32(len(info.bucket))]; chain != 0; chain = info.chain[chain] {
+			sym := &info.symtab[chain]
+			typ := _ELF64_ST_TYPE(sym.st_info)
+			bind := _ELF64_ST_BIND(sym.st_info)
+			if typ != _STT_FUNC || bind != _STB_GLOBAL && bind != _STB_WEAK || sym.st_shndx == _SHN_UNDEF {
+				continue
+			}
+			if k.name != gostringnocopy(&info.symstrings[sym.st_name]) {
+				continue
+			}
+
+			// Check symbol version.
+			if info.versym != nil && version != 0 && int32(info.versym[chain]&0x7fff) != version {
+				continue
+			}
+
+			*k.ptr = info.load_offset + uintptr(sym.st_value)
+			break
+		}
+	}
+}
+
+func sysargs(argc int32, argv **byte) {
+	n := argc + 1
+
+	// skip envp to get to ELF auxiliary vector.
+	for argv_index(argv, n) != nil {
+		n++
+	}
+
+	// skip NULL separator
+	n++
+
+	// now argv+n is auxv
+	auxv := (*[1 << 32]elf64Auxv)(add(unsafe.Pointer(argv), uintptr(n)*ptrSize))
+
+	for i := 0; auxv[i].a_type != _AT_NULL; i++ {
+		av := &auxv[i]
+		switch av.a_type {
+		case _AT_SYSINFO_EHDR:
+			if av.a_val == 0 {
+				// Something went wrong
+				continue
+			}
+			var info vdso_info
+			// TODO(rsc): I don't understand why the compiler thinks info escapes
+			// when passed to the three functions below.
+			info1 := (*vdso_info)(noescape(unsafe.Pointer(&info)))
+			vdso_init_from_sysinfo_ehdr(info1, (*elf64Ehdr)(unsafe.Pointer(uintptr(av.a_val))))
+			vdso_parse_symbols(info1, vdso_find_version(info1, &linux26))
+
+		case _AT_RANDOM:
+			startup_random_data = (*byte)(unsafe.Pointer(uintptr(av.a_val)))
+			startup_random_data_len = 16
+		}
+	}
+}

src/runtime/vdso_none.go

+// Copyright 2014 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.
+
+// +build !linux !amd64
+
+package runtime
+
+func sysargs(argc int32, argv **byte) {
+}