From: js1304@gmail.com To: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>, Alexander Potapenko <glider@google.com>, Dmitry Vyukov <dvyukov@google.com>, kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Namhyung Kim <namhyung@kernel.org>, Wengang Wang <wen.gang.wang@oracle.com>, Joonsoo Kim <iamjoonsoo.kim@lge.com> Subject: [PATCH 14/18] mm/vchecker: make callstack depth configurable Date: Tue, 28 Nov 2017 16:48:49 +0900 [thread overview] Message-ID: <1511855333-3570-15-git-send-email-iamjoonsoo.kim@lge.com> (raw) In-Reply-To: <1511855333-3570-1-git-send-email-iamjoonsoo.kim@lge.com> From: Joonsoo Kim <iamjoonsoo.kim@lge.com> Getting full callstack is heavy job so it's sometimes better to reduce this overhead by limiting callstack depth. So, this patch makes the callstack depth configurable by using debugfs interface. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> --- mm/kasan/vchecker.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 77 insertions(+), 4 deletions(-) diff --git a/mm/kasan/vchecker.c b/mm/kasan/vchecker.c index acead62..4d140e7 100644 --- a/mm/kasan/vchecker.c +++ b/mm/kasan/vchecker.c @@ -27,6 +27,7 @@ struct vchecker { bool enabled; + unsigned int callstack_depth; struct list_head cb_list; }; @@ -309,13 +310,14 @@ static void filter_vchecker_stacks(struct stack_trace *trace, } static noinline depot_stack_handle_t save_stack(struct stackdepot *s, - unsigned long ret_ip, bool *is_new) + unsigned long ret_ip, unsigned int max_entries, + bool *is_new) { unsigned long entries[VCHECKER_STACK_DEPTH]; struct stack_trace trace = { .nr_entries = 0, .entries = entries, - .max_entries = VCHECKER_STACK_DEPTH, + .max_entries = max_entries, .skip = VCHECKER_SKIP_DEPTH, }; depot_stack_handle_t handle; @@ -489,6 +491,70 @@ static const struct file_operations enable_fops = { .release = single_release, }; +static int callstack_depth_show(struct seq_file *f, void *v) +{ + struct kmem_cache *s = f->private; + struct vchecker *checker = s->vchecker_cache.checker; + + mutex_lock(&vchecker_meta); + seq_printf(f, "%u\n", checker->callstack_depth); + mutex_unlock(&vchecker_meta); + + return 0; +} + +static int callstack_depth_open(struct inode *inode, struct file *file) +{ + return single_open(file, callstack_depth_show, inode->i_private); +} + +static ssize_t callstack_depth_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char callstack_depth_chars[32]; + unsigned int callstack_depth; + struct kmem_cache *s = file_inode(filp)->i_private; + + if (cnt >= 32 || cnt == 0) + return -EINVAL; + + if (copy_from_user(&callstack_depth_chars, ubuf, cnt)) + return -EFAULT; + + if (isspace(callstack_depth_chars[0])) { + callstack_depth = VCHECKER_STACK_DEPTH; + goto setup; + } + + callstack_depth_chars[cnt - 1] = '\0'; + if (kstrtouint(callstack_depth_chars, 10, &callstack_depth)) + return -EINVAL; + + if (callstack_depth > VCHECKER_STACK_DEPTH) + callstack_depth = VCHECKER_STACK_DEPTH; + +setup: + mutex_lock(&vchecker_meta); + if (s->vchecker_cache.checker->enabled || + !list_empty(&s->vchecker_cache.checker->cb_list)) { + mutex_unlock(&vchecker_meta); + return -EINVAL; + } + + s->vchecker_cache.checker->callstack_depth = callstack_depth; + mutex_unlock(&vchecker_meta); + + return cnt; +} + +static const struct file_operations callstack_depth_fops = { + .open = callstack_depth_open, + .write = callstack_depth_write, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static int init_value(struct kmem_cache *s, struct vchecker_cb *cb, char *buf, size_t cnt) { @@ -571,7 +637,8 @@ static bool check_value(struct kmem_cache *s, struct vchecker_cb *cb, if (!write) goto check; - handle = save_stack(NULL, ret_ip, NULL); + handle = save_stack(NULL, ret_ip, + s->vchecker_cache.checker->callstack_depth, NULL); if (!handle) { pr_err("VCHECKER: %s: fail at addr %p\n", __func__, object); dump_stack(); @@ -715,7 +782,8 @@ static bool check_callstack(struct kmem_cache *s, struct vchecker_cb *cb, struct vchecker_callstack_arg *arg = cb->arg; int idx; - handle = save_stack(arg->s, ret_ip, &is_new); + handle = save_stack(arg->s, ret_ip, + s->vchecker_cache.checker->callstack_depth, &is_new); if (!is_new) return true; @@ -825,6 +893,7 @@ static int alloc_vchecker(struct kmem_cache *s) if (!checker) return -ENOMEM; + checker->callstack_depth = VCHECKER_STACK_DEPTH; INIT_LIST_HEAD(&checker->cb_list); s->vchecker_cache.checker = checker; @@ -848,6 +917,10 @@ static int register_debugfs(struct kmem_cache *s) if (!debugfs_create_file("enable", 0600, dir, s, &enable_fops)) return -ENOMEM; + if (!debugfs_create_file("callstack_depth", 0600, dir, s, + &callstack_depth_fops)) + return -ENOMEM; + for (i = 0; i < ARRAY_SIZE(vchecker_types); i++) { t = &vchecker_types[i]; if (!debugfs_create_file(t->name, 0600, dir, s, t->fops)) -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: js1304@gmail.com To: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>, Alexander Potapenko <glider@google.com>, Dmitry Vyukov <dvyukov@google.com>, kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Namhyung Kim <namhyung@kernel.org>, Wengang Wang <wen.gang.wang@oracle.com>, Joonsoo Kim <iamjoonsoo.kim@lge.com> Subject: [PATCH 14/18] mm/vchecker: make callstack depth configurable Date: Tue, 28 Nov 2017 16:48:49 +0900 [thread overview] Message-ID: <1511855333-3570-15-git-send-email-iamjoonsoo.kim@lge.com> (raw) In-Reply-To: <1511855333-3570-1-git-send-email-iamjoonsoo.kim@lge.com> From: Joonsoo Kim <iamjoonsoo.kim@lge.com> Getting full callstack is heavy job so it's sometimes better to reduce this overhead by limiting callstack depth. So, this patch makes the callstack depth configurable by using debugfs interface. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> --- mm/kasan/vchecker.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 77 insertions(+), 4 deletions(-) diff --git a/mm/kasan/vchecker.c b/mm/kasan/vchecker.c index acead62..4d140e7 100644 --- a/mm/kasan/vchecker.c +++ b/mm/kasan/vchecker.c @@ -27,6 +27,7 @@ struct vchecker { bool enabled; + unsigned int callstack_depth; struct list_head cb_list; }; @@ -309,13 +310,14 @@ static void filter_vchecker_stacks(struct stack_trace *trace, } static noinline depot_stack_handle_t save_stack(struct stackdepot *s, - unsigned long ret_ip, bool *is_new) + unsigned long ret_ip, unsigned int max_entries, + bool *is_new) { unsigned long entries[VCHECKER_STACK_DEPTH]; struct stack_trace trace = { .nr_entries = 0, .entries = entries, - .max_entries = VCHECKER_STACK_DEPTH, + .max_entries = max_entries, .skip = VCHECKER_SKIP_DEPTH, }; depot_stack_handle_t handle; @@ -489,6 +491,70 @@ static const struct file_operations enable_fops = { .release = single_release, }; +static int callstack_depth_show(struct seq_file *f, void *v) +{ + struct kmem_cache *s = f->private; + struct vchecker *checker = s->vchecker_cache.checker; + + mutex_lock(&vchecker_meta); + seq_printf(f, "%u\n", checker->callstack_depth); + mutex_unlock(&vchecker_meta); + + return 0; +} + +static int callstack_depth_open(struct inode *inode, struct file *file) +{ + return single_open(file, callstack_depth_show, inode->i_private); +} + +static ssize_t callstack_depth_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char callstack_depth_chars[32]; + unsigned int callstack_depth; + struct kmem_cache *s = file_inode(filp)->i_private; + + if (cnt >= 32 || cnt == 0) + return -EINVAL; + + if (copy_from_user(&callstack_depth_chars, ubuf, cnt)) + return -EFAULT; + + if (isspace(callstack_depth_chars[0])) { + callstack_depth = VCHECKER_STACK_DEPTH; + goto setup; + } + + callstack_depth_chars[cnt - 1] = '\0'; + if (kstrtouint(callstack_depth_chars, 10, &callstack_depth)) + return -EINVAL; + + if (callstack_depth > VCHECKER_STACK_DEPTH) + callstack_depth = VCHECKER_STACK_DEPTH; + +setup: + mutex_lock(&vchecker_meta); + if (s->vchecker_cache.checker->enabled || + !list_empty(&s->vchecker_cache.checker->cb_list)) { + mutex_unlock(&vchecker_meta); + return -EINVAL; + } + + s->vchecker_cache.checker->callstack_depth = callstack_depth; + mutex_unlock(&vchecker_meta); + + return cnt; +} + +static const struct file_operations callstack_depth_fops = { + .open = callstack_depth_open, + .write = callstack_depth_write, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static int init_value(struct kmem_cache *s, struct vchecker_cb *cb, char *buf, size_t cnt) { @@ -571,7 +637,8 @@ static bool check_value(struct kmem_cache *s, struct vchecker_cb *cb, if (!write) goto check; - handle = save_stack(NULL, ret_ip, NULL); + handle = save_stack(NULL, ret_ip, + s->vchecker_cache.checker->callstack_depth, NULL); if (!handle) { pr_err("VCHECKER: %s: fail at addr %p\n", __func__, object); dump_stack(); @@ -715,7 +782,8 @@ static bool check_callstack(struct kmem_cache *s, struct vchecker_cb *cb, struct vchecker_callstack_arg *arg = cb->arg; int idx; - handle = save_stack(arg->s, ret_ip, &is_new); + handle = save_stack(arg->s, ret_ip, + s->vchecker_cache.checker->callstack_depth, &is_new); if (!is_new) return true; @@ -825,6 +893,7 @@ static int alloc_vchecker(struct kmem_cache *s) if (!checker) return -ENOMEM; + checker->callstack_depth = VCHECKER_STACK_DEPTH; INIT_LIST_HEAD(&checker->cb_list); s->vchecker_cache.checker = checker; @@ -848,6 +917,10 @@ static int register_debugfs(struct kmem_cache *s) if (!debugfs_create_file("enable", 0600, dir, s, &enable_fops)) return -ENOMEM; + if (!debugfs_create_file("callstack_depth", 0600, dir, s, + &callstack_depth_fops)) + return -ENOMEM; + for (i = 0; i < ARRAY_SIZE(vchecker_types); i++) { t = &vchecker_types[i]; if (!debugfs_create_file(t->name, 0600, dir, s, t->fops)) -- 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-11-28 7:51 UTC|newest] Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-11-28 7:48 [PATCH 00/18] introduce a new tool, valid access checker js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 01/18] mm/kasan: make some kasan functions global js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 02/18] vchecker: introduce the valid access checker js1304 2017-11-28 7:48 ` js1304 2017-11-28 19:41 ` Andi Kleen 2017-11-28 19:41 ` Andi Kleen 2017-11-29 5:36 ` Joonsoo Kim 2017-11-29 5:36 ` Joonsoo Kim 2017-12-01 5:08 ` kbuild test robot 2017-12-01 8:01 ` Joonsoo Kim 2017-12-01 8:01 ` Joonsoo Kim 2017-11-28 7:48 ` [PATCH 03/18] vchecker: mark/unmark the shadow of the allocated objects js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 04/18] vchecker: prepare per object memory for vchecker js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 05/18] vchecker: store/report callstack of value writer js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 06/18] lib/stackdepot: Add is_new arg to depot_save_stack js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 07/18] lib/stackdepot: extend stackdepot API to support per-user stackdepot js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 08/18] vchecker: Add 'callstack' checker js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 09/18] vchecker: Support toggle on/off of callstack check js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 10/18] vchecker: Use __GFP_ATOMIC to save stacktrace js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 11/18] vchecker: consistently exclude vchecker's stacktrace js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 12/18] vchecker: fix 'remove' handling on callstack checker js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 13/18] mm/vchecker: support inline KASAN build js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` js1304 [this message] 2017-11-28 7:48 ` [PATCH 14/18] mm/vchecker: make callstack depth configurable js1304 2017-11-28 7:48 ` [PATCH 15/18] mm/vchecker: pass allocation caller address to vchecker hook js1304 2017-11-28 7:48 ` js1304 2017-12-01 2:39 ` kbuild test robot 2017-12-01 3:01 ` kbuild test robot 2017-11-28 7:48 ` [PATCH 16/18] mm/vchecker: support allocation caller filter js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 17/18] lib/vchecker_test: introduce a sample for vchecker test js1304 2017-11-28 7:48 ` js1304 2017-11-28 7:48 ` [PATCH 18/18] doc: add vchecker document js1304 2017-11-28 7:48 ` js1304 2017-11-29 9:27 ` [PATCH 00/18] introduce a new tool, valid access checker Dmitry Vyukov 2017-11-29 9:27 ` Dmitry Vyukov 2017-12-01 7:46 ` Joonsoo Kim 2017-12-01 7:46 ` Joonsoo Kim 2017-12-22 1:51 ` Joonsoo Kim 2017-12-22 1:51 ` Joonsoo Kim 2018-01-18 22:39 ` Andrew Morton 2018-01-18 22:39 ` Andrew Morton
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