[ added Petr to CC list ] On Mon, 25 Jan 2016, Torsten Duwe wrote: > * create the appropriate files+functions > arch/powerpc/include/asm/livepatch.h > klp_check_compiler_support, > klp_arch_set_pc > arch/powerpc/kernel/livepatch.c with a stub for > klp_write_module_reloc > This is architecture-independent work in progress. > * introduce a fixup in arch/powerpc/kernel/entry_64.S > for local calls that are becoming global due to live patching. > And of course do the main KLP thing: return to a maybe different > address, possibly altered by the live patching ftrace op. > > Signed-off-by: Torsten Duwe <duwe@xxxxxxx> Hi, I have a few questions... We still need Petr's patch from [1] to make livepatch work, right? Could you, please, add it to this patch set to make it self-sufficient? Second, what is the situation with mcount prologue between gcc < 6 and gcc-6? Are there only 12 bytes in gcc-6 prologue? If yes, we need to change Petr's patch to make it more general and to be able to cope with different prologues. This is unfortunate. Either way, please mention it somewhere in a changelog. I haven't reviewed the patch properly yet, but there is a comment below. [1] http://lkml.kernel.org/g/20151203160004.GE8047@xxxxxxxxxxxxxxx > +/** > + * klp_write_module_reloc() - write a relocation in a module > + * @mod: module in which the section to be modified is found > + * @type: ELF relocation type (see asm/elf.h) > + * @loc: address that the relocation should be written to > + * @value: relocation value (sym address + addend) > + * > + * This function writes a relocation to the specified location for > + * a particular module. > + */ > +int klp_write_module_reloc(struct module *mod, unsigned long type, > + unsigned long loc, unsigned long value) > +{ > + /* This requires infrastructure changes; we need the loadinfos. */ > + pr_err("lpc_write_module_reloc not yet supported\n"); This is a nit, but there is no lpc_write_module_reloc. It should be klp_write_module_reloc. Thanks, Miroslav -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
