Hi, On Thu, 14 Apr 2016, Maxim Kuvyrkov wrote:
> It appears that implementing -fprolog-pad=N option in GCC will not > enable kernel live-patching support for AArch64. The proposal for the > option was to make GCC output a given number of NOPs at the beginning of > each function, and then the kernel could use that NOP pad to insert > whatever instructions it needs. The modification of kernel instruction > stream needs to be done atomically, and, unfortunately, it seems the > kernel can use only architecture-provided atomicity primitives -- i.e., > changing at most 8 bytes at a time. Replace first nop with a breakpoint, handle rest of patching in breakpoint handler, patch breakpoint insn last, no need to atomically patch multiple instructions. Ciao, Michael.
