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| author | Michael Pratt <mpratt@google.com> | 2022-02-24 16:46:54 -0500 |
|---|---|---|
| committer | Michael Pratt <mpratt@google.com> | 2022-04-21 18:07:03 +0000 |
| commit | f7b12ff6fbad25ea30ae9f16dd1443eb9b76766d (patch) | |
| tree | 5e8f03f34586130cca2ab9281ab492b6a5c148ea /src/syscall/syscall_linux.go | |
| parent | 15602e88658a9dd43cec4220e01ef408d273f028 (diff) | |
| download | go-f7b12ff6fbad25ea30ae9f16dd1443eb9b76766d.tar.xz | |
syscall: define RawSyscall in terms of RawSyscall6 on linux
For #51087
Change-Id: I63e07638507328efe33dbf7dd5f8a8b78890e037
Reviewed-on: https://go-review.googlesource.com/c/go/+/388476
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Diffstat (limited to 'src/syscall/syscall_linux.go')
| -rw-r--r-- | src/syscall/syscall_linux.go | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/src/syscall/syscall_linux.go b/src/syscall/syscall_linux.go index b0e2cdb682..a9a8ecbefd 100644 --- a/src/syscall/syscall_linux.go +++ b/src/syscall/syscall_linux.go @@ -18,7 +18,6 @@ import ( func Syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno) -func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) // N.B. RawSyscall6 is provided via linkname by runtime/internal/syscall. // @@ -27,6 +26,27 @@ func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno) +// N.B. For the Syscall functions below: +// +// //go:uintptrkeepalive because the uintptr argument may be converted pointers +// that need to be kept alive in the caller (this is implied for RawSyscall6 +// 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. +// +// //go:linkname to ensure ABI wrappers are generated for external callers +// (notably x/sys/unix assembly). + +//go:uintptrkeepalive +//go:nosplit +//go:linkname RawSyscall +func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) { + return RawSyscall6(trap, a1, a2, a3, 0, 0, 0) +} + func rawSyscallNoError(trap, a1, a2, a3 uintptr) (r1, r2 uintptr) /* |