From c8dc49fb0318088e30040d1162cea181931f1ab4 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Wed, 12 Oct 2016 14:28:05 +0000 Subject: syscall, internal/syscall/unix: Fix getrandom, clone on sparc64 Since sparc is a valid architecture, the name of getrandom_linux_sparc.go means that it will be ignored on sparc64, even though it's whitelisted with a +build line. On SPARC, clone has a unique return value convention which requires some inline assembly to convert it to the normal convention. Reviewed-on: https://go-review.googlesource.com/30873 From-SVN: r241051 --- .../internal/syscall/unix/getrandom_linux_sparc.go | 11 --- .../syscall/unix/getrandom_linux_sparcx.go | 11 +++ libgo/go/syscall/clone_linux.c | 100 +++++++++++++++++++++ libgo/go/syscall/exec_linux.go | 19 ++-- 4 files changed, 120 insertions(+), 21 deletions(-) delete mode 100644 libgo/go/internal/syscall/unix/getrandom_linux_sparc.go create mode 100644 libgo/go/internal/syscall/unix/getrandom_linux_sparcx.go create mode 100644 libgo/go/syscall/clone_linux.c (limited to 'libgo/go') diff --git a/libgo/go/internal/syscall/unix/getrandom_linux_sparc.go b/libgo/go/internal/syscall/unix/getrandom_linux_sparc.go deleted file mode 100644 index 4874ec1..0000000 --- a/libgo/go/internal/syscall/unix/getrandom_linux_sparc.go +++ /dev/null @@ -1,11 +0,0 @@ -// Copyright 2016 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 sparc sparc64 - -package unix - -// Linux getrandom system call number. -// See GetRandom in getrandom_linux.go. -const randomTrap uintptr = 347 diff --git a/libgo/go/internal/syscall/unix/getrandom_linux_sparcx.go b/libgo/go/internal/syscall/unix/getrandom_linux_sparcx.go new file mode 100644 index 0000000..4874ec1 --- /dev/null +++ b/libgo/go/internal/syscall/unix/getrandom_linux_sparcx.go @@ -0,0 +1,11 @@ +// Copyright 2016 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 sparc sparc64 + +package unix + +// Linux getrandom system call number. +// See GetRandom in getrandom_linux.go. +const randomTrap uintptr = 347 diff --git a/libgo/go/syscall/clone_linux.c b/libgo/go/syscall/clone_linux.c new file mode 100644 index 0000000..a1a15ea --- /dev/null +++ b/libgo/go/syscall/clone_linux.c @@ -0,0 +1,100 @@ +/* clone_linux.c -- consistent wrapper around Linux clone syscall + + Copyright 2016 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 +#include +#include + +#include "runtime.h" + +long rawClone (unsigned long flags, void *child_stack, void *ptid, void *ctid, struct pt_regs *regs) __asm__ (GOSYM_PREFIX "syscall.rawClone"); + +long +rawClone (unsigned long flags, void *child_stack, void *ptid, void *ctid, struct pt_regs *regs) +{ +#if defined(__arc__) || defined(__aarch64__) || defined(__arm__) || defined(__mips__) || defined(__hppa__) || defined(__powerpc__) || defined(__score__) || defined(__i386__) || defined(__xtensa__) + // CLONE_BACKWARDS + return syscall(__NR_clone, flags, child_stack, ptid, regs, ctid); +#elif defined(__s390__) || defined(__cris__) + // CLONE_BACKWARDS2 + return syscall(__NR_clone, child_stack, flags, ptid, ctid, regs); +#elif defined(__microblaze__) + // CLONE_BACKWARDS3 + return syscall(__NR_clone, flags, child_stack, 0, ptid, ctid, regs); +#elif defined(__sparc__) + + /* SPARC has a unique return value convention: + + Parent --> %o0 == child's pid, %o1 == 0 + Child --> %o0 == parent's pid, %o1 == 1 + + Translate this to look like a normal clone. */ + +# if defined(__arch64__) + +# define SYSCALL_STRING \ + "ta 0x6d;" \ + "bcc,pt %%xcc, 1f;" \ + " mov 0, %%g1;" \ + "sub %%g0, %%o0, %%o0;" \ + "mov 1, %%g1;" \ + "1:" + +# define SYSCALL_CLOBBERS \ + "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \ + "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \ + "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", \ + "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31", \ + "f32", "f34", "f36", "f38", "f40", "f42", "f44", "f46", \ + "f48", "f50", "f52", "f54", "f56", "f58", "f60", "f62", \ + "cc", "memory" + +# else /* __arch64__ */ + +# define SYSCALL_STRING \ + "ta 0x10;" \ + "bcc 1f;" \ + " mov 0, %%g1;" \ + "sub %%g0, %%o0, %%o0;" \ + "mov 1, %%g1;" \ + "1:" + +# define SYSCALL_CLOBBERS \ + "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \ + "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \ + "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", \ + "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31", \ + "cc", "memory" + +# endif /* __arch64__ */ + + register long o0 __asm__ ("o0") = (long)flags; + register long o1 __asm__ ("o1") = (long)child_stack; + register long o2 __asm__ ("o2") = (long)ptid; + register long o3 __asm__ ("o3") = (long)ctid; + register long o4 __asm__ ("o4") = (long)regs; + register long g1 __asm__ ("g1") = __NR_clone; + + __asm __volatile (SYSCALL_STRING : + "=r" (g1), "=r" (o0), "=r" (o1) : + "0" (g1), "1" (o0), "2" (o1), + "r" (o2), "r" (o3), "r" (o4) : + SYSCALL_CLOBBERS); + + if (__builtin_expect(g1 != 0, 0)) + { + errno = -o0; + o0 = -1L; + } + else + o0 &= (o1 - 1); + + return o0; + +#else + return syscall(__NR_clone, flags, child_stack, ptid, ctid, regs); +#endif +} diff --git a/libgo/go/syscall/exec_linux.go b/libgo/go/syscall/exec_linux.go index 581a988..83d9c1ca 100644 --- a/libgo/go/syscall/exec_linux.go +++ b/libgo/go/syscall/exec_linux.go @@ -7,7 +7,6 @@ package syscall import ( - "runtime" "unsafe" ) @@ -49,6 +48,9 @@ type SysProcAttr struct { func runtime_BeforeFork() func runtime_AfterFork() +// Implemented in clone_linux.c +func rawClone(flags _C_ulong, child_stack *byte, ptid *Pid_t, ctid *Pid_t, regs unsafe.Pointer) _C_long + // Fork, dup fd onto 0..len(fd), and exec(argv0, argvv, envv) in child. // If a dup or exec fails, write the errno error to pipe. // (Pipe is close-on-exec so if exec succeeds, it will be closed.) @@ -64,6 +66,7 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr // declarations require heap allocation (e.g., err1). var ( r1 uintptr + r2 _C_long err1 Errno err2 Errno nextfd int @@ -98,20 +101,16 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr // About to call fork. // No more allocation or calls of non-assembly functions. runtime_BeforeFork() - if runtime.GOARCH == "s390x" || runtime.GOARCH == "s390" { - r1, _, err1 = RawSyscall6(SYS_CLONE, 0, uintptr(SIGCHLD)|sys.Cloneflags, 0, 0, 0, 0) - } else { - r1, _, err1 = RawSyscall6(SYS_CLONE, uintptr(SIGCHLD)|sys.Cloneflags, 0, 0, 0, 0, 0) - } - if err1 != 0 { + r2 = rawClone(_C_ulong(uintptr(SIGCHLD)|sys.Cloneflags), nil, nil, nil, unsafe.Pointer(nil)) + if r2 < 0 { runtime_AfterFork() - return 0, err1 + return 0, GetErrno() } - if r1 != 0 { + if r2 != 0 { // parent; return PID runtime_AfterFork() - pid = int(r1) + pid = int(r2) if sys.UidMappings != nil || sys.GidMappings != nil { Close(p[0]) -- cgit v1.1