On Thu, Sep 05, 2019 at 01:19:06PM +0200, Jiri Kosina wrote: > On Thu, 5 Sep 2019, Petr Mladek wrote: > > > > I don't have a number, but it's very common to patch a function which > > > uses jump labels or alternatives. > > > > Really? My impression is that both alternatives and jump_labels > > are used in hot paths. I would expect them mostly in core code > > that is always loaded. > > > > Alternatives are often used in assembly that we are not able > > to livepatch anyway. > > > > Or are they spread widely via some macros or inlined functions? > > All the indirect jumps are turned into alternatives when retpolines are in > place. Actually in C code those are done by the compiler as calls/jumps to __x86_indirect_thunk_*. But there are still a bunch of paravirt patched instructions and alternatives used throughout the kernel. -- Josh
