On Fri, Dec 14, 2018 at 04:34:23PM -0500, Joe Lawrence wrote: > On 12/14/2018 11:56 AM, Nicholas Mc Guire wrote: > > Sparse reported warnings about non-static symbols. For the variables a > > simple static attribute is fine - for those symbols referenced by > > livepatch via klp_func the symbol-names must be unmodified in the > > relocation table - to resolve this the __noclone attribute (as > ^^^^^^^^^^ > nit: symbol table > > > suggested by Joe Lawrence <joe.lawrence@xxxxxxxxxx>) is used > > for the statically declared functions. > > > > Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx> > > Link: https://lkml.org/lkml/2018/12/13/827 Needs a: Suggested-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx> > > > > diff --git a/samples/livepatch/livepatch-shadow-fix1.c b/samples/livepatch/livepatch-shadow-fix1.c > > index 49b1355..eaab10f 100644 > > --- a/samples/livepatch/livepatch-shadow-fix1.c > > +++ b/samples/livepatch/livepatch-shadow-fix1.c > > @@ -71,7 +71,7 @@ static int shadow_leak_ctor(void *obj, void *shadow_data, void *ctor_data) > > return 0; > > } > > > > -struct dummy *livepatch_fix1_dummy_alloc(void) > > +static __noclone struct dummy *livepatch_fix1_dummy_alloc(void) > > { > > struct dummy *d; > > void *leak; > > @@ -108,7 +108,7 @@ static void livepatch_fix1_dummy_leak_dtor(void *obj, void *shadow_data) > > __func__, d, *shadow_leak); > > } > > > > -void livepatch_fix1_dummy_free(struct dummy *d) > > +static __noclone void livepatch_fix1_dummy_free(struct dummy *d) > > { > > void **shadow_leak; > > > > diff --git a/samples/livepatch/livepatch-shadow-mod.c b/samples/livepatch/livepatch-shadow-mod.c > > index 4c54b25..0a72bc2 100644 > > --- a/samples/livepatch/livepatch-shadow-mod.c > > +++ b/samples/livepatch/livepatch-shadow-mod.c > > @@ -30,6 +30,11 @@ > > * memory leak, please load these modules at your own risk -- some > > * amount of memory may leaked before the bug is patched. > > * > > + * NOTE - the __noclone attribute to those functions that are to be > > + * shared with other modules while being declared static. As livepatch > > + * needs the unmodified symbol names and the usual "static" would > > + * invoke gccs cloning mechanism that renames the functions this > > + * needs to be suppressed with the additional __noclone attribute. > > I like the idea of providing the sample code reader this information, > but since the compiler might also optimize livepatch-callbacks-busymod.c > :: busymod_work_func(), it too should be annotated __noclone. Would > that file deserve a similar comment? > > I don't have a strong opinion, but would throw my vote at leaving this > in the commit message only. Agreed, IMO the comment isn't needed. > BTW, Petr/Miroslav/Josh, should we be annotating the selftests in > similar fashion? Probably so. -- Josh
