| // Copyright 2022 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 syscall provides the syscall primitives required for the runtime. |
| package syscall |
| |
| import ( |
| _ "unsafe" // for go:linkname |
| ) |
| |
| // TODO(https://go.dev/issue/51087): This package is incomplete and currently |
| // only contains very minimal support for Linux. |
| |
| // Syscall6 calls system call number 'num' with arguments a1-6. |
| func Syscall6(num, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, errno uintptr) |
| |
| // syscall_RawSyscall6 is a push linkname to export Syscall6 as |
| // syscall.RawSyscall6. |
| // |
| // //go:uintptrkeepalive because the uintptr argument may be converted pointers |
| // that need to be kept alive in the caller (this is implied for Syscall6 since |
| // it has no body). |
| // |
| // //go:nosplit because stack copying does not account for uintptrkeepalive, so |
| // the stack must not grow. Stack copying cannot blindly assume that all |
| // uintptr arguments are pointers, because some values may look like pointers, |
| // but not really be pointers, and adjusting their value would break the call. |
| // |
| // This is a separate wrapper because we can't export one function as two |
| // names. The assembly implementations name themselves Syscall6 would not be |
| // affected by a linkname. |
| // |
| //go:uintptrkeepalive |
| //go:nosplit |
| //go:linkname syscall_RawSyscall6 syscall.RawSyscall6 |
| func syscall_RawSyscall6(num, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, errno uintptr) { |
| return Syscall6(num, a1, a2, a3, a4, a5, a6) |
| } |