Update the "psx" README file.
Now that the "psx" package can be compiled CGO_ENABLED=0 mention that
in the README.
Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
diff --git a/psx/README b/psx/README
index c25538a..cd9c651 100644
--- a/psx/README
+++ b/psx/README
@@ -1,20 +1,28 @@
-Package psx provides a CGo backed API for invoking system calls in a
-way that each system call is mirrored on all pthreads of the combined
-Go/CGo runtime. Since the Go runtime treats all pthreads as
-interchangeable, a feature like this is needed to meaningfully change
-process privilege (including dropping privilege) in a Go program
-running on Linux. This package is required by:
+Package "psx" provides an API for invoking system calls in a way that
+each system call is mirrored on all OS threads of the combined Go/CGo
+runtime. Since the Go runtime treats OS threads as interchangeable, a
+feature like this is needed to meaningfully change process privilege
+(including dropping privilege) in a Go program running on Linux. This
+package is required by:
"kernel.org/pub/linux/libs/security/libcap/cap"
-The functionality is implemented by a C library: libpsx, which is
-distributed with the libcap. The official release announcement site
-for libcap and libpsx is:
+When compiled CGO_ENABLED=0, the functionality requires go1.16+ to
+build. That release of Go introduced syscall.AllThreadsSyscall*()
+APIs. When compiled this way, the "psx" package functions
+psx.Syscall3() and psx.Syscall6() are aliased to
+syscall.AllThreadsSyscall() and syscall.AllThreadsSyscall6()
+respectively.
+
+When compiled CGO_ENABLED=1, the functionality is implemented by C
+code, [lib]psx, which is distributed with libcap.
+
+The official release announcement site for libcap and libpsx is:
https://sites.google.com/site/fullycapable/
-Like libcap/libpsx itself, the psx package is distributed with a "you
-choose" License. Specifically: BSD three clause, or GPL2. See the
+Like libcap/libpsx itself, the "psx" package is distributed with a
+"you choose" License. Specifically: BSD three clause, or GPL2. See the
LICENSE file.
Andrew G. Morgan <morgan@kernel.org>
