x86/static_call: Add optimized static call implementation for 64-bit
Add the optimized static call implementation for x86-64. For each key,
a temporary trampoline is created, named __static_call_tramp_<key>. The
trampoline has an indirect jump to the destination function.
Objtool uses the trampoline naming convention to detect all the call
sites. It then annotates those call sites in the .static_call_sites
section.
During boot (and module init), the call sites are patched to call
directly into the destination function. The temporary trampoline is
then no longer used.
Link: http://lkml.kernel.org/r/41741f0d3a54003881c19a6fff5110f98dbf86cd.1541711457.git.jpoimboe@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
9 files changed
