| Message ID | 20240809073309.2134488-3-kees@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | slab: Allocate and use per-call-site caches | expand |
On Fri, Aug 9, 2024 at 12:33 AM Kees Cook <kees@kernel.org> wrote: > > In order to process builtin alloc_tags much earlier during boot (before > register_codetag() is processed), provide codetag_early_walk() that > perform a lockless walk with a specified callback function. This will be > used to allocate required caches that cannot be allocated on demand. > > Signed-off-by: Kees Cook <kees@kernel.org> > --- > Cc: Suren Baghdasaryan <surenb@google.com> > Cc: Kent Overstreet <kent.overstreet@linux.dev> > Cc: Vlastimil Babka <vbabka@suse.cz> > Cc: Christoph Lameter <cl@linux.com> > Cc: Pekka Enberg <penberg@kernel.org> > Cc: David Rientjes <rientjes@google.com> > Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Roman Gushchin <roman.gushchin@linux.dev> > Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> > Cc: linux-mm@kvack.org > --- > include/linux/codetag.h | 2 ++ > lib/codetag.c | 16 ++++++++++++++++ > 2 files changed, 18 insertions(+) > > diff --git a/include/linux/codetag.h b/include/linux/codetag.h > index c2a579ccd455..9eb1fcd90570 100644 > --- a/include/linux/codetag.h > +++ b/include/linux/codetag.h > @@ -64,6 +64,8 @@ void codetag_lock_module_list(struct codetag_type *cttype, bool lock); > bool codetag_trylock_module_list(struct codetag_type *cttype); > struct codetag_iterator codetag_get_ct_iter(struct codetag_type *cttype); > struct codetag *codetag_next_ct(struct codetag_iterator *iter); > +void codetag_early_walk(const struct codetag_type_desc *desc, > + void (*callback)(struct codetag *ct)); > > void codetag_to_text(struct seq_buf *out, struct codetag *ct); > > diff --git a/lib/codetag.c b/lib/codetag.c > index ef7634c7ee18..9d563c8c088a 100644 > --- a/lib/codetag.c > +++ b/lib/codetag.c > @@ -154,6 +154,22 @@ static struct codetag_range get_section_range(struct module *mod, > }; > } > > +void codetag_early_walk(const struct codetag_type_desc *desc, > + void (*callback)(struct codetag *ct)) > +{ > + struct codetag_range range; > + struct codetag *ct; > + > + range = get_section_range(NULL, desc->section); > + if (!range.start || !range.stop || > + range.start == range.stop || > + range.start > range.stop) > + return; I think this check can be simplified to: if (!range.start || range.start >= range.stop) return; nit: Technically (!range.start) should also never trigger. In a valid image these symbols are either missing (range.start == range.stop == NULL) or both are defined and (range.start < range.stop). > + > + for (ct = range.start; ct < range.stop; ct = ((void *)ct + desc->tag_size)) > + callback(ct); > +} > + > static int codetag_module_init(struct codetag_type *cttype, struct module *mod) > { > struct codetag_range range; > -- > 2.34.1 >
On Thu, Aug 29, 2024 at 08:39:29AM -0700, Suren Baghdasaryan wrote: > On Fri, Aug 9, 2024 at 12:33 AM Kees Cook <kees@kernel.org> wrote: > > > > In order to process builtin alloc_tags much earlier during boot (before > > register_codetag() is processed), provide codetag_early_walk() that > > perform a lockless walk with a specified callback function. This will be > > used to allocate required caches that cannot be allocated on demand. > > > > Signed-off-by: Kees Cook <kees@kernel.org> > > --- > > Cc: Suren Baghdasaryan <surenb@google.com> > > Cc: Kent Overstreet <kent.overstreet@linux.dev> > > Cc: Vlastimil Babka <vbabka@suse.cz> > > Cc: Christoph Lameter <cl@linux.com> > > Cc: Pekka Enberg <penberg@kernel.org> > > Cc: David Rientjes <rientjes@google.com> > > Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> > > Cc: Andrew Morton <akpm@linux-foundation.org> > > Cc: Roman Gushchin <roman.gushchin@linux.dev> > > Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> > > Cc: linux-mm@kvack.org > > --- > > include/linux/codetag.h | 2 ++ > > lib/codetag.c | 16 ++++++++++++++++ > > 2 files changed, 18 insertions(+) > > > > diff --git a/include/linux/codetag.h b/include/linux/codetag.h > > index c2a579ccd455..9eb1fcd90570 100644 > > --- a/include/linux/codetag.h > > +++ b/include/linux/codetag.h > > @@ -64,6 +64,8 @@ void codetag_lock_module_list(struct codetag_type *cttype, bool lock); > > bool codetag_trylock_module_list(struct codetag_type *cttype); > > struct codetag_iterator codetag_get_ct_iter(struct codetag_type *cttype); > > struct codetag *codetag_next_ct(struct codetag_iterator *iter); > > +void codetag_early_walk(const struct codetag_type_desc *desc, > > + void (*callback)(struct codetag *ct)); > > > > void codetag_to_text(struct seq_buf *out, struct codetag *ct); > > > > diff --git a/lib/codetag.c b/lib/codetag.c > > index ef7634c7ee18..9d563c8c088a 100644 > > --- a/lib/codetag.c > > +++ b/lib/codetag.c > > @@ -154,6 +154,22 @@ static struct codetag_range get_section_range(struct module *mod, > > }; > > } > > > > +void codetag_early_walk(const struct codetag_type_desc *desc, > > + void (*callback)(struct codetag *ct)) > > +{ > > + struct codetag_range range; > > + struct codetag *ct; > > + > > + range = get_section_range(NULL, desc->section); > > + if (!range.start || !range.stop || > > + range.start == range.stop || > > + range.start > range.stop) > > + return; > > I think this check can be simplified to: > > if (!range.start || range.start >= range.stop) > return; > > nit: Technically (!range.start) should also never trigger. In a valid > image these symbols are either missing (range.start == range.stop == > NULL) or both are defined and (range.start < range.stop). Yeah, all true. I was mainly copying all the checks that existed in the "slow path" version. I will adjust this for the next version.
diff --git a/include/linux/codetag.h b/include/linux/codetag.h index c2a579ccd455..9eb1fcd90570 100644 --- a/include/linux/codetag.h +++ b/include/linux/codetag.h @@ -64,6 +64,8 @@ void codetag_lock_module_list(struct codetag_type *cttype, bool lock); bool codetag_trylock_module_list(struct codetag_type *cttype); struct codetag_iterator codetag_get_ct_iter(struct codetag_type *cttype); struct codetag *codetag_next_ct(struct codetag_iterator *iter); +void codetag_early_walk(const struct codetag_type_desc *desc, + void (*callback)(struct codetag *ct)); void codetag_to_text(struct seq_buf *out, struct codetag *ct); diff --git a/lib/codetag.c b/lib/codetag.c index ef7634c7ee18..9d563c8c088a 100644 --- a/lib/codetag.c +++ b/lib/codetag.c @@ -154,6 +154,22 @@ static struct codetag_range get_section_range(struct module *mod, }; } +void codetag_early_walk(const struct codetag_type_desc *desc, + void (*callback)(struct codetag *ct)) +{ + struct codetag_range range; + struct codetag *ct; + + range = get_section_range(NULL, desc->section); + if (!range.start || !range.stop || + range.start == range.stop || + range.start > range.stop) + return; + + for (ct = range.start; ct < range.stop; ct = ((void *)ct + desc->tag_size)) + callback(ct); +} + static int codetag_module_init(struct codetag_type *cttype, struct module *mod) { struct codetag_range range;
In order to process builtin alloc_tags much earlier during boot (before register_codetag() is processed), provide codetag_early_walk() that perform a lockless walk with a specified callback function. This will be used to allocate required caches that cannot be allocated on demand. Signed-off-by: Kees Cook <kees@kernel.org> --- Cc: Suren Baghdasaryan <surenb@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: linux-mm@kvack.org --- include/linux/codetag.h | 2 ++ lib/codetag.c | 16 ++++++++++++++++ 2 files changed, 18 insertions(+)