syscall: do not use NULL for zero-length read, write
Avoids problems running Linux binaries under QEMU.
R=r, gri
CC=golang-dev
https://golang.org/cl/4151043
diff --git a/src/pkg/syscall/zsyscall_darwin_amd64.go b/src/pkg/syscall/zsyscall_darwin_amd64.go
index 6dca198..f7a37b6 100644
--- a/src/pkg/syscall/zsyscall_darwin_amd64.go
+++ b/src/pkg/syscall/zsyscall_darwin_amd64.go
@@ -121,6 +121,8 @@
var _p0 unsafe.Pointer
if len(p) > 0 {
_p0 = unsafe.Pointer(&p[0])
+ } else {
+ _p0 = unsafe.Pointer(&_zero)
}
r0, _, e1 := Syscall6(SYS_RECVFROM, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(flags), uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(fromlen)))
n = int(r0)
@@ -134,6 +136,8 @@
var _p0 unsafe.Pointer
if len(buf) > 0 {
_p0 = unsafe.Pointer(&buf[0])
+ } else {
+ _p0 = unsafe.Pointer(&_zero)
}
_, _, e1 := Syscall6(SYS_SENDTO, uintptr(s), uintptr(_p0), uintptr(len(buf)), uintptr(flags), uintptr(to), uintptr(addrlen))
errno = int(e1)
@@ -155,6 +159,8 @@
var _p0 unsafe.Pointer
if len(mib) > 0 {
_p0 = unsafe.Pointer(&mib[0])
+ } else {
+ _p0 = unsafe.Pointer(&_zero)
}
_, _, e1 := Syscall6(SYS___SYSCTL, uintptr(_p0), uintptr(len(mib)), uintptr(unsafe.Pointer(old)), uintptr(unsafe.Pointer(oldlen)), uintptr(unsafe.Pointer(new)), uintptr(newlen))
errno = int(e1)
@@ -377,6 +383,8 @@
var _p0 unsafe.Pointer
if len(buf) > 0 {
_p0 = unsafe.Pointer(&buf[0])
+ } else {
+ _p0 = unsafe.Pointer(&_zero)
}
r0, _, e1 := Syscall6(SYS_GETDIRENTRIES64, uintptr(fd), uintptr(_p0), uintptr(len(buf)), uintptr(unsafe.Pointer(basep)), 0, 0)
n = int(r0)
@@ -414,6 +422,8 @@
var _p0 unsafe.Pointer
if len(buf) > 0 {
_p0 = unsafe.Pointer(&buf[0])
+ } else {
+ _p0 = unsafe.Pointer(&_zero)
}
r0, _, e1 := Syscall(SYS_GETFSSTAT64, uintptr(_p0), uintptr(len(buf)), uintptr(flags))
n = int(r0)
@@ -601,6 +611,8 @@
var _p0 unsafe.Pointer
if len(p) > 0 {
_p0 = unsafe.Pointer(&p[0])
+ } else {
+ _p0 = unsafe.Pointer(&_zero)
}
r0, _, e1 := Syscall6(SYS_PREAD, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), 0, 0)
n = int(r0)
@@ -614,6 +626,8 @@
var _p0 unsafe.Pointer
if len(p) > 0 {
_p0 = unsafe.Pointer(&p[0])
+ } else {
+ _p0 = unsafe.Pointer(&_zero)
}
r0, _, e1 := Syscall6(SYS_PWRITE, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), 0, 0)
n = int(r0)
@@ -627,6 +641,8 @@
var _p0 unsafe.Pointer
if len(p) > 0 {
_p0 = unsafe.Pointer(&p[0])
+ } else {
+ _p0 = unsafe.Pointer(&_zero)
}
r0, _, e1 := Syscall(SYS_READ, uintptr(fd), uintptr(_p0), uintptr(len(p)))
n = int(r0)
@@ -640,6 +656,8 @@
var _p0 unsafe.Pointer
if len(buf) > 0 {
_p0 = unsafe.Pointer(&buf[0])
+ } else {
+ _p0 = unsafe.Pointer(&_zero)
}
r0, _, e1 := Syscall(SYS_READLINK, uintptr(unsafe.Pointer(StringBytePtr(path))), uintptr(_p0), uintptr(len(buf)))
n = int(r0)
@@ -871,6 +889,8 @@
var _p0 unsafe.Pointer
if len(p) > 0 {
_p0 = unsafe.Pointer(&p[0])
+ } else {
+ _p0 = unsafe.Pointer(&_zero)
}
r0, _, e1 := Syscall(SYS_WRITE, uintptr(fd), uintptr(_p0), uintptr(len(p)))
n = int(r0)
