Add NEWS about unprivileged user support

diff --git a/NEWS b/NEWS
index a56787bd35c2ec92d3e422ad98ac1abec8bff9cf..818fd6267bb06d82a38a45818e230b437c1784c1 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,43 @@
 * What's new
 
+- Support for unprivileged users:
+  *****************************************************************************
+  * WARNING!!!!!!!!!!
+  * This feature is EXPERIMENTAL at this time and should be used with care.
+  * This feature allows systemtap kernel modules to be loaded by unprivileged
+  * users. The user interface and restrictions will change as this feature
+  * evolves.
+  *****************************************************************************
+  - Systemtap modules generated from scripts which use a restricted subset of
+    the features available may be loaded by staprun for unprivileged users.
+    Previously, staprun would load modules only for root or for members of the
+    groups stapdev and stapusr.
+  - Using the --unprivileged option on stap enables translation-time checking
+    for use by unprivileged users (see restrictions below).
+  - All modules deemed suitable for use by unprivileged users will be signed
+    by stap (see module signing in release 0.9.8 below).
+  - Modules signed by trusted users and verified by staprun will be loaded by
+    staprun regardless of the user's privilege level.
+  - The system administrator asserts the trustworthiness of a user by running
+    stap-authorize-signing-cert <cert-file> as root, where <cert-file> can
+    be found in ~<user>/.systemtap/ssl/server/stap.cert.
+  - Restrictions are intentionally strict at this time and will be relaxed in
+    the future:
+     - probe points are restricted to:
+         begin, begin(n), end, end(n), error(n), never,
+         timer.{jiffies,s,sec,ms,msec,us,usec,ns,nsec}(n)*, timer.hz(n)
+     - embedded C code is not allowed.
+     - use of tapset functions using embedded C code is restricted.
+     - accessing the kernel memory space is not allowed.
+     - The following command line options may not be used:
+       -g, -I, -D, -R
+       -r may not be used to select a target kernel other than one from
+       /lib/modules/RELEASE/build, where RELEASE is a currently installed kernel
+         release.
+     - The following environment variables may not be set:
+       SYSTEMTAP_RUNTIME, SYSTEMTAP_TAPSET, SYSTEMTAP_DEBUGINFO_PATH
+  - nss and nss-tools are required to use this feature.
+
 - Systemwide kernel .function.return (kretprobe) maxactive defaults may
   be overridden with the -DKRETACTIVE=nnn parameter.