kprobes: allow to specify custom allocator for insn caches

The current two insn slot caches both use module_alloc/module_free to
allocate and free insn slot cache pages.

For s390 this is not sufficient since there is the need to allocate insn
slots that are either within the vmalloc module area or within dma memory.

Therefore add a mechanism which allows to specify an own allocator for an
own insn slot cache.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 077f653..925eaf2 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -268,6 +268,8 @@ extern void kprobes_inc_nmissed_count(struct kprobe *p);
 
 struct kprobe_insn_cache {
 	struct mutex mutex;
+	void *(*alloc)(void);	/* allocate insn page */
+	void (*free)(void *);	/* free insn page */
 	struct list_head pages; /* list of kprobe_insn_page */
 	size_t insn_size;	/* size of instruction slot */
 	int nr_garbage;