From d2d0ee2049e78d8c57025e0861425808825c759e Mon Sep 17 00:00:00 2001 From: Cuong Manh Le Date: Sat, 25 Feb 2023 16:32:15 +0700 Subject: [PATCH] [release-branch.go1.20] syscall: fix invalid unsafe.Pointer conversion on Windows Updates #58714 Fixes #58774 Change-Id: Ifa5c059ed5e358ed98aee7e83b95dd1806b535f7 Reviewed-on: https://go-review.googlesource.com/c/go/+/471335 Reviewed-by: Than McIntosh TryBot-Result: Gopher Robot Reviewed-by: Ian Lance Taylor Run-TryBot: Cuong Manh Le Reviewed-by: Bryan Mills (cherry picked from commit de8c999159bb72e8a43f9b38b6369fc43eca572e) Reviewed-on: https://go-review.googlesource.com/c/go/+/471599 Reviewed-by: Cuong Manh Le Auto-Submit: Dmitri Shuralyov Reviewed-by: Dmitri Shuralyov Run-TryBot: Bryan Mills --- src/syscall/env_windows.go | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/src/syscall/env_windows.go b/src/syscall/env_windows.go index cd085a9e44..94364f930c 100644 --- a/src/syscall/env_windows.go +++ b/src/syscall/env_windows.go @@ -74,21 +74,24 @@ func Clearenv() { } func Environ() []string { - s, e := GetEnvironmentStrings() + envp, e := GetEnvironmentStrings() if e != nil { return nil } - defer FreeEnvironmentStrings(s) + defer FreeEnvironmentStrings(envp) + r := make([]string, 0, 50) // Empty with room to grow. - for from, i, p := 0, 0, (*[1 << 24]uint16)(unsafe.Pointer(s)); true; i++ { - if p[i] == 0 { - // empty string marks the end - if i <= from { - break - } - r = append(r, string(utf16.Decode(p[from:i]))) - from = i + 1 + const size = unsafe.Sizeof(*envp) + for *envp != 0 { // environment block ends with empty string + // find NUL terminator + end := unsafe.Pointer(envp) + for *(*uint16)(end) != 0 { + end = unsafe.Add(end, size) } + + entry := unsafe.Slice(envp, (uintptr(end)-uintptr(unsafe.Pointer(envp)))/size) + r = append(r, string(utf16.Decode(entry))) + envp = (*uint16)(unsafe.Add(end, size)) } return r } -- 2.48.1