my_tramp[12]? are declared as global functions in C, but they are not
marked global in the inline assembly definition. This mismatch confuses
Clang's Control-Flow Integrity checking. Fix the definitions by adding
.globl.
Link: https://lkml.kernel.org/r/20201113183414.1446671-1-samitolvanen@google.com
Fixes: 9d907f1ae8 ("ftrace/samples: Add a sample module that implements modify_ftrace_direct()")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add another module sample that registers a direct trampoline to a function
via register_ftrace_direct(). Having another module that does this allows to
test the use case of multiple direct callers registered, as more than one
direct caller goes into another path, and is needed to perform proper
testing of the register_ftrace_direct() call.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>