PR28140: kernel 5.14-rc adaptation, jump_label_patch

Linux commit ab3257042c2 makes it necessary for us to stop overriding
CONFIG_STACK_VALIDATION= (originally a workaround for a 2016 rawhide
bug).  This fixes the tracepoints.stp test case.

diff --git a/buildrun.cxx b/buildrun.cxx
index ae27ddea499148a029766c7a38177a671c412ebb..6a6725db68cb417d278bf8927644c86f91cbe1a8 100644 (file)
--- a/buildrun.cxx
+++ b/buildrun.cxx
@@ -120,7 +120,13 @@ make_any_make_cmd(systemtap_session& s, const string& dir, const string& target)
       "CONFIG_DEBUG_INFO_BTF_MODULES=",
       
       // RHBZ1321628: suppress stack validation; expected to be temporary
-      "CONFIG_STACK_VALIDATION=",
+      // "CONFIG_STACK_VALIDATION=",
+      
+      // PR28140 ... as of kernel 5.14-rc*, this is actively
+      // dangerous, because it skips the full objtool processing
+      // chain, and the resulting tracepoint call sites in the ko are
+      // not properly instrumented.  See also Linux commit
+      // ab3257042c2.
     };
 
   // PR10280: suppress symbol versioning to restrict to exact kernel version