Hi Steve, On Sat, Aug 30, 2008 at 2:17 AM, Steve VanDeBogart <[EMAIL PROTECTED]> wrote: > Valgrind annotations for the slab allocator: Malloc-like and free-like > for cache_alloc and free. Telling Valgrind a region is free-like clears > all the valid bits, so slabs with constructors need different treatment; > tell Valgrind about slab objects when first constructed and free them > when the slab is destroyed.
OK, I'm biased (I'm one of the kmemcheck developers) but these hooks to SLAB are too ugly to live with. My preferred solution is that you reuse the kmemcheck annotations kmemcheck_slab_alloc()/kmemcheck_slab_free() we have: http://git.kernel.org/?p=linux/kernel/git/x86/linux-2.6-tip.git;a=commitdiff;h=30532cb3c49a2a9fed94127aab26003c52398a51 Maybe making valgrind code a "UML port" (plus some more) of kmemcheck. > Signed-off-by: Steve VanDeBogart <[EMAIL PROTECTED]> > --- > > Index: linux-2.6.27-rc5/mm/slab.c > =================================================================== > --- linux-2.6.27-rc5.orig/mm/slab.c 2008-08-29 14:24:25.000000000 -0700 > +++ linux-2.6.27-rc5/mm/slab.c 2008-08-29 14:24:42.000000000 -0700 > @@ -111,6 +111,7 @@ > #include <linux/rtmutex.h> > #include <linux/reciprocal_div.h> > #include <linux/debugobjects.h> > +#include <linux/memcheck.h> > > #include <asm/cacheflush.h> > #include <asm/tlbflush.h> > @@ -1906,6 +1907,8 @@ > int i; > for (i = 0; i < cachep->num; i++) { > void *objp = index_to_obj(cachep, slabp, i); > + if (cachep->ctor) > + VALGRIND_FREELIKE_BLOCK(objp, 0); > > if (cachep->flags & SLAB_POISON) { > #ifdef CONFIG_DEBUG_PAGEALLOC > @@ -1932,6 +1935,15 @@ > #else > static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab > *slabp) > { > +#ifdef CONFIG_VALGRIND_SUPPORT > + int i; > + if (cachep->ctor) { > + for (i = 0; i < cachep->num; i++) { > + void *objp = index_to_obj(cachep, slabp, i); > + VALGRIND_FREELIKE_BLOCK(objp, 0); > + } > + } > +#endif > } > #endif > > @@ -2635,6 +2647,9 @@ > > for (i = 0; i < cachep->num; i++) { > void *objp = index_to_obj(cachep, slabp, i); > + if (cachep->ctor) > + VALGRIND_MALLOCLIKE_BLOCK(objp, cachep->buffer_size, > + 0, 0); > #if DEBUG > /* need to poison the objs? */ > if (cachep->flags & SLAB_POISON) > @@ -3466,6 +3481,8 @@ > objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); > prefetchw(objp); > > + if (!cachep->ctor) > + VALGRIND_MALLOCLIKE_BLOCK(objp, cachep->buffer_size, 0, 0); > if (unlikely((flags & __GFP_ZERO) && objp)) > memset(objp, 0, obj_size(cachep)); > > @@ -3578,6 +3595,9 @@ > { > struct array_cache *ac = cpu_cache_get(cachep); > > + if (!cachep->ctor) > + VALGRIND_FREELIKE_BLOCK(objp, 0); > + > check_irq_off(); > objp = cache_free_debugcheck(cachep, objp, > __builtin_return_address(0)); I'm not sure why you want to treat caches with constructor differently. Sure, the memory regions *are* initialized but from programmer's point of view you're not supposed to be touching the memory unless you got it from kmalloc() or kmem_cache_alloc(). Same goes for kfree() and kmem_cache_free() -- no touchy touchy after you pass a pointer to either of the functions (unless you're RCU, of course). Pekka ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
