Subject: + kprobes-allow-to-specify-custum-allocator-for-insn-caches.patch added to -mm tree
To: heiko.carstens@xxxxxxxxxx,ananth@xxxxxxxxxx,masami.hiramatsu.pt@xxxxxxxxxxx,mingo@xxxxxxxxxx,schwidefsky@xxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Fri, 23 Aug 2013 15:52:50 -0700
The patch titled
Subject: kprobes: allow to specify custum allocator for insn caches
has been added to the -mm tree. Its filename is
kprobes-allow-to-specify-custum-allocator-for-insn-caches.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kprobes-allow-to-specify-custum-allocator-for-insn-caches.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kprobes-allow-to-specify-custum-allocator-for-insn-caches.patch
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------------------------------------------------------
From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Subject: kprobes: allow to specify custum 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@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/kprobes.h | 2 ++
kernel/kprobes.c | 20 ++++++++++++++++++--
2 files changed, 20 insertions(+), 2 deletions(-)
diff -puN include/linux/kprobes.h~kprobes-allow-to-specify-custum-allocator-for-insn-caches include/linux/kprobes.h
--- a/include/linux/kprobes.h~kprobes-allow-to-specify-custum-allocator-for-insn-caches
+++ a/include/linux/kprobes.h
@@ -268,6 +268,8 @@ extern void kprobes_inc_nmissed_count(st
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;
diff -puN kernel/kprobes.c~kprobes-allow-to-specify-custum-allocator-for-insn-caches kernel/kprobes.c
--- a/kernel/kprobes.c~kprobes-allow-to-specify-custum-allocator-for-insn-caches
+++ a/kernel/kprobes.c
@@ -112,6 +112,7 @@ static struct kprobe_blackpoint kprobe_b
struct kprobe_insn_page {
struct list_head list;
kprobe_opcode_t *insns; /* Page of instruction slots */
+ struct kprobe_insn_cache *cache;
int nused;
int ngarbage;
char slot_used[];
@@ -132,8 +133,20 @@ enum kprobe_slot_state {
SLOT_USED = 2,
};
+static void *alloc_insn_page(void)
+{
+ return module_alloc(PAGE_SIZE);
+}
+
+static void free_insn_page(void *page)
+{
+ module_free(NULL, page);
+}
+
struct kprobe_insn_cache kprobe_insn_slots = {
.mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex),
+ .alloc = alloc_insn_page,
+ .free = free_insn_page,
.pages = LIST_HEAD_INIT(kprobe_insn_slots.pages),
.insn_size = MAX_INSN_SIZE,
.nr_garbage = 0,
@@ -182,7 +195,7 @@ kprobe_opcode_t __kprobes *__get_insn_sl
* kernel image and loaded module images reside. This is required
* so x86_64 can correctly handle the %rip-relative fixups.
*/
- kip->insns = module_alloc(PAGE_SIZE);
+ kip->insns = c->alloc();
if (!kip->insns) {
kfree(kip);
goto out;
@@ -192,6 +205,7 @@ kprobe_opcode_t __kprobes *__get_insn_sl
kip->slot_used[0] = SLOT_USED;
kip->nused = 1;
kip->ngarbage = 0;
+ kip->cache = c;
list_add(&kip->list, &c->pages);
slot = kip->insns;
out:
@@ -213,7 +227,7 @@ static int __kprobes collect_one_slot(st
*/
if (!list_is_singular(&kip->list)) {
list_del(&kip->list);
- module_free(NULL, kip->insns);
+ kip->cache->free(kip->insns);
kfree(kip);
}
return 1;
@@ -274,6 +288,8 @@ out:
/* For optimized_kprobe buffer */
struct kprobe_insn_cache kprobe_optinsn_slots = {
.mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex),
+ .alloc = alloc_insn_page,
+ .free = free_insn_page,
.pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages),
/* .insn_size is initialized later */
.nr_garbage = 0,
_
Patches currently in -mm which might be from heiko.carstens@xxxxxxxxxx are
kprobes-unify-insn-caches.patch
kprobes-allow-to-specify-custum-allocator-for-insn-caches.patch
s390-kprobes-add-support-for-pc-relative-long-displacement-instructions.patch
linux-next.patch
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