From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3ACA3C4332E for ; Thu, 19 Mar 2020 15:10:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E5FB72072D for ; Thu, 19 Mar 2020 15:10:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="c7Klv0vN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727801AbgCSPK6 (ORCPT ); Thu, 19 Mar 2020 11:10:58 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:46992 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727416AbgCSPK5 (ORCPT ); Thu, 19 Mar 2020 11:10:57 -0400 Received: by mail-wr1-f68.google.com with SMTP id j17so48500wru.13 for ; Thu, 19 Mar 2020 08:10:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=cb6lUWyfJYVDyB4wPMBGrg1wfAdW+cF1bQpBgq0CT7Y=; b=c7Klv0vNP99AyjdT4jr6H+7iiqfnKhXfBD4VFyXSSgd2m9P3Kp3gHCFXWMGlN3aTRp 7Dg5i8KXvX2S+zumbEMhOhUSGNhr6fwgVpuWc6sT3ximt84reRt2xXpYSDcQyplN9VWM zJDH1R19GK2mg383Rhif204i15wBnhoMGnvmm4g8Ll7Ha/aAnIe50SskxRarwqRYIzw4 3Wl1OYUMOYN+Ncr17uivP+WNFpM4Vgs1DSKljRHCz/dm3Sykzf3OQk/2pmvH2pGWYcBz 730fp549MDeLcvgAYA7XR4VSZmjbJyc/GniJ4PoTGI5/ptTr/4wXXymVmSV1vcxXigpd 5Y1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=cb6lUWyfJYVDyB4wPMBGrg1wfAdW+cF1bQpBgq0CT7Y=; b=GU+TK7bIIwlD+rBsgg7amWxrQGqlYigxu22g57Q46qvhPZarXd899Q4fMR1CmjGoug VIHZ5xKGD0Zi8vz5W0OgJZoURbzBra8Mhkd2sjRRsQrs4AEHmSn/AzQlXq35PUe3GN8j oF2wNRVTnJXcdga9qyYRXorceTC9WWjEloCzVGgXH4gzaV6KKJm73emCNvIWHdyH0k4P mIkUVb06vyVbPdxXdpRiPNnEr+TtptpHua+f3R6gBO4nAR1vZNtbGSInR8i29vTL5uE/ BuPvEfohup1ksuVu18KN6ez5H5b3etzxO0J3AsxcDOXuqjPjHKJIye5a613iJZkHzJKf 6TSA== X-Gm-Message-State: ANhLgQ3jidlMrp3mhC4g/7lmEFs20uUyuNtx7kmr52YxJjFnAK3R0EdW J5j4U/HCTMnTUQqexinRvyg= X-Google-Smtp-Source: ADFU+vtye7kTva61Pwz0k9E9TfAz6os/mdPZe3n6bmVprHwdvcFdbEV7fw6DioovANaNiRvewK1kWg== X-Received: by 2002:a5d:5710:: with SMTP id a16mr4964015wrv.5.1584630654144; Thu, 19 Mar 2020 08:10:54 -0700 (PDT) Received: from localhost.localdomain ([141.226.9.174]) by smtp.gmail.com with ESMTPSA id t193sm3716959wmt.14.2020.03.19.08.10.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Mar 2020 08:10:53 -0700 (PDT) From: Amir Goldstein To: Jan Kara Cc: Al Viro , linux-fsdevel@vger.kernel.org Subject: [PATCH v3 10/14] fanotify: divorce fanotify_path_event and fanotify_fid_event Date: Thu, 19 Mar 2020 17:10:18 +0200 Message-Id: <20200319151022.31456-11-amir73il@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200319151022.31456-1-amir73il@gmail.com> References: <20200319151022.31456-1-amir73il@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Breakup the union and make them both inherit from abstract fanotify_event. fanotify_path_event, fanotify_fid_event and fanotify_perm_event inherit from fanotify_event. type field in abstract fanotify_event determines the concrete event type. fanotify_path_event, fanotify_fid_event and fanotify_perm_event are allocated from separate memcache pools. The separation of struct fanotify_fid_hdr from the file handle that was done for efficient packing of fanotify_event is no longer needed, so re-group the file handle fields under struct fanotify_fh. The struct fanotify_fid, which served to group fsid and file handle for the union is no longer needed so break it up. Rename fanotify_perm_event casting macro to FANOTIFY_PERM(), so that FANOTIFY_PE() and FANOTIFY_FE() can be used as casting macros to fanotify_path_event and fanotify_fid_event. Suggested-by: Jan Kara Signed-off-by: Amir Goldstein --- fs/notify/fanotify/fanotify.c | 201 +++++++++++++++++++++-------- fs/notify/fanotify/fanotify.h | 146 ++++++++++++--------- fs/notify/fanotify/fanotify_user.c | 69 +++++----- 3 files changed, 265 insertions(+), 151 deletions(-) diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 960f4f4d9e8f..4c5dd5db21bd 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -17,6 +17,42 @@ #include "fanotify.h" +static bool fanotify_path_equal(struct path *p1, struct path *p2) +{ + return p1->mnt == p2->mnt && p1->dentry == p2->dentry; +} + +static inline bool fanotify_fsid_equal(__kernel_fsid_t *fsid1, + __kernel_fsid_t *fsid2) +{ + return fsid1->val[0] == fsid1->val[0] && fsid2->val[1] == fsid2->val[1]; +} + +static bool fanotify_fh_equal(struct fanotify_fh *fh1, + struct fanotify_fh *fh2) +{ + if (fh1->type != fh2->type || fh1->len != fh2->len) + return false; + + /* Do not merge events if we failed to encode fh */ + if (fh1->type == FILEID_INVALID) + return false; + + return !fh1->len || + !memcmp(fanotify_fh_buf(fh1), fanotify_fh_buf(fh2), fh1->len); +} + +static bool fanotify_fid_event_equal(struct fanotify_fid_event *ffe1, + struct fanotify_fid_event *ffe2) +{ + /* Do not merge fid events without object fh */ + if (!ffe1->object_fh.len) + return false; + + return fanotify_fsid_equal(&ffe1->fsid, &ffe2->fsid) && + fanotify_fh_equal(&ffe1->object_fh, &ffe2->object_fh); +} + static bool should_merge(struct fsnotify_event *old_fsn, struct fsnotify_event *new_fsn) { @@ -26,14 +62,15 @@ static bool should_merge(struct fsnotify_event *old_fsn, old = FANOTIFY_E(old_fsn); new = FANOTIFY_E(new_fsn); - if (old_fsn->objectid != new_fsn->objectid || old->pid != new->pid || - old->fh_type != new->fh_type || old->fh_len != new->fh_len) + if (old_fsn->objectid != new_fsn->objectid || + old->type != new->type || old->pid != new->pid) return false; - if (fanotify_event_has_path(old)) { - return old->path.mnt == new->path.mnt && - old->path.dentry == new->path.dentry; - } else if (fanotify_event_has_fid(old)) { + switch (old->type) { + case FANOTIFY_EVENT_TYPE_PATH: + return fanotify_path_equal(fanotify_event_path(old), + fanotify_event_path(new)); + case FANOTIFY_EVENT_TYPE_FID: /* * We want to merge many dirent events in the same dir (i.e. * creates/unlinks/renames), but we do not want to merge dirent @@ -42,11 +79,15 @@ static bool should_merge(struct fsnotify_event *old_fsn, * mask FAN_CREATE|FAN_DELETE|FAN_ONDIR if it describes mkdir+ * unlink pair or rmdir+create pair of events. */ - return (old->mask & FS_ISDIR) == (new->mask & FS_ISDIR) && - fanotify_fid_equal(&old->fid, &new->fid, old->fh_len); + if ((old->mask & FS_ISDIR) != (new->mask & FS_ISDIR)) + return false; + + return fanotify_fid_event_equal(FANOTIFY_FE(old), + FANOTIFY_FE(new)); + default: + WARN_ON_ONCE(1); } - /* Do not merge events if we failed to encode fid */ return false; } @@ -213,15 +254,14 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, return test_mask & user_mask; } -static int fanotify_encode_fid(struct fanotify_event *event, - struct inode *inode, gfp_t gfp, - __kernel_fsid_t *fsid) +static void fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode, + gfp_t gfp) { - struct fanotify_fid *fid = &event->fid; - int dwords, bytes = 0; - int err, type; + int dwords, type, bytes = 0; + char *ext_buf = NULL; + void *buf = fh->buf; + int err; - fid->ext_fh = NULL; dwords = 0; err = -ENOENT; type = exportfs_encode_inode_fh(inode, NULL, &dwords, NULL); @@ -232,31 +272,32 @@ static int fanotify_encode_fid(struct fanotify_event *event, if (bytes > FANOTIFY_INLINE_FH_LEN) { /* Treat failure to allocate fh as failure to allocate event */ err = -ENOMEM; - fid->ext_fh = kmalloc(bytes, gfp); - if (!fid->ext_fh) + ext_buf = kmalloc(bytes, gfp); + if (!ext_buf) goto out_err; + + *fanotify_fh_ext_buf_ptr(fh) = ext_buf; + buf = ext_buf; } - type = exportfs_encode_inode_fh(inode, fanotify_fid_fh(fid, bytes), - &dwords, NULL); + type = exportfs_encode_inode_fh(inode, buf, &dwords, NULL); err = -EINVAL; if (!type || type == FILEID_INVALID || bytes != dwords << 2) goto out_err; - fid->fsid = *fsid; - event->fh_len = bytes; + fh->type = type; + fh->len = bytes; - return type; + return; out_err: - pr_warn_ratelimited("fanotify: failed to encode fid (fsid=%x.%x, " - "type=%d, bytes=%d, err=%i)\n", - fsid->val[0], fsid->val[1], type, bytes, err); - kfree(fid->ext_fh); - fid->ext_fh = NULL; - event->fh_len = 0; - - return FILEID_INVALID; + pr_warn_ratelimited("fanotify: failed to encode fid (type=%d, len=%d, err=%i)\n", + type, bytes, err); + kfree(ext_buf); + *fanotify_fh_ext_buf_ptr(fh) = NULL; + /* Report the event without a file identifier on encode error */ + fh->type = FILEID_INVALID; + fh->len = 0; } /* @@ -282,10 +323,17 @@ struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, __kernel_fsid_t *fsid) { struct fanotify_event *event = NULL; + struct fanotify_fid_event *ffe = NULL; gfp_t gfp = GFP_KERNEL_ACCOUNT; struct inode *id = fanotify_fid_inode(inode, mask, data, data_type); const struct path *path = fsnotify_data_path(data, data_type); + /* Make sure we can easily cast between inherited structs */ + BUILD_BUG_ON(offsetof(struct fanotify_event, fse) != 0); + BUILD_BUG_ON(offsetof(struct fanotify_fid_event, fae) != 0); + BUILD_BUG_ON(offsetof(struct fanotify_path_event, fae) != 0); + BUILD_BUG_ON(offsetof(struct fanotify_perm_event, fae) != 0); + /* * For queues with unlimited length lost events are not expected and * can possibly have security implications. Avoid losing events when @@ -306,14 +354,29 @@ struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, pevent = kmem_cache_alloc(fanotify_perm_event_cachep, gfp); if (!pevent) goto out; + event = &pevent->fae; + event->type = FANOTIFY_EVENT_TYPE_PATH_PERM; pevent->response = 0; pevent->state = FAN_EVENT_INIT; goto init; } - event = kmem_cache_alloc(fanotify_event_cachep, gfp); - if (!event) - goto out; + + if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { + ffe = kmem_cache_alloc(fanotify_fid_event_cachep, gfp); + if (!ffe) + goto out; + + event = &ffe->fae; + event->type = FANOTIFY_EVENT_TYPE_FID; + } else { + event = kmem_cache_alloc(fanotify_path_event_cachep, gfp); + if (!event) + goto out; + + event->type = FANOTIFY_EVENT_TYPE_PATH; + } + init: __maybe_unused /* * Use the victim inode instead of the watching inode as the id for @@ -326,18 +389,22 @@ init: __maybe_unused event->pid = get_pid(task_pid(current)); else event->pid = get_pid(task_tgid(current)); - event->fh_len = 0; - if (id && FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { - /* Report the event without a file identifier on encode error */ - event->fh_type = fanotify_encode_fid(event, id, gfp, fsid); - } else if (path) { - event->fh_type = FILEID_ROOT; - event->path = *path; - path_get(path); - } else { - event->fh_type = FILEID_INVALID; - event->path.mnt = NULL; - event->path.dentry = NULL; + if (fanotify_event_has_fid(event)) { + ffe->object_fh.len = 0; + if (fsid) + ffe->fsid = *fsid; + if (id) + fanotify_encode_fh(&ffe->object_fh, id, gfp); + } else if (fanotify_event_has_path(event)) { + struct path *p = fanotify_event_path(event); + + if (path) { + *p = *path; + path_get(path); + } else { + p->mnt = NULL; + p->dentry = NULL; + } } out: memalloc_unuse_memcg(); @@ -457,7 +524,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, ret = 0; } else if (fanotify_is_perm_event(mask)) { - ret = fanotify_get_response(group, FANOTIFY_PE(fsn_event), + ret = fanotify_get_response(group, FANOTIFY_PERM(fsn_event), iter_info); } finish: @@ -476,22 +543,44 @@ static void fanotify_free_group_priv(struct fsnotify_group *group) free_uid(user); } +static void fanotify_free_path_event(struct fanotify_event *event) +{ + path_put(fanotify_event_path(event)); + kmem_cache_free(fanotify_path_event_cachep, event); +} + +static void fanotify_free_perm_event(struct fanotify_event *event) +{ + path_put(fanotify_event_path(event)); + kmem_cache_free(fanotify_perm_event_cachep, event); +} + +static void fanotify_free_fid_event(struct fanotify_fid_event *ffe) +{ + if (fanotify_fh_has_ext_buf(&ffe->object_fh)) + kfree(fanotify_fh_ext_buf(&ffe->object_fh)); + kmem_cache_free(fanotify_fid_event_cachep, ffe); +} + static void fanotify_free_event(struct fsnotify_event *fsn_event) { struct fanotify_event *event; event = FANOTIFY_E(fsn_event); - if (fanotify_event_has_path(event)) - path_put(&event->path); - else if (fanotify_event_has_ext_fh(event)) - kfree(event->fid.ext_fh); put_pid(event->pid); - if (fanotify_is_perm_event(event->mask)) { - kmem_cache_free(fanotify_perm_event_cachep, - FANOTIFY_PE(fsn_event)); - return; + switch (event->type) { + case FANOTIFY_EVENT_TYPE_PATH: + fanotify_free_path_event(event); + break; + case FANOTIFY_EVENT_TYPE_PATH_PERM: + fanotify_free_perm_event(event); + break; + case FANOTIFY_EVENT_TYPE_FID: + fanotify_free_fid_event(FANOTIFY_FE(event)); + break; + default: + WARN_ON_ONCE(1); } - kmem_cache_free(fanotify_event_cachep, event); } static void fanotify_free_mark(struct fsnotify_mark *fsn_mark) diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index 68b30504284c..1bc73a65d9d2 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -5,7 +5,8 @@ #include extern struct kmem_cache *fanotify_mark_cache; -extern struct kmem_cache *fanotify_event_cachep; +extern struct kmem_cache *fanotify_fid_event_cachep; +extern struct kmem_cache *fanotify_path_event_cachep; extern struct kmem_cache *fanotify_perm_event_cachep; /* Possible states of the permission event */ @@ -18,96 +19,102 @@ enum { /* * 3 dwords are sufficient for most local fs (64bit ino, 32bit generation). - * For 32bit arch, fid increases the size of fanotify_event by 12 bytes and - * fh_* fields increase the size of fanotify_event by another 4 bytes. - * For 64bit arch, fid increases the size of fanotify_fid by 8 bytes and - * fh_* fields are packed in a hole after mask. + * fh buf should be dword aligned. On 64bit arch, the ext_buf pointer is + * stored in either the first or last 2 dwords. */ -#if BITS_PER_LONG == 32 #define FANOTIFY_INLINE_FH_LEN (3 << 2) -#else -#define FANOTIFY_INLINE_FH_LEN (4 << 2) -#endif -struct fanotify_fid { - __kernel_fsid_t fsid; - union { - unsigned char fh[FANOTIFY_INLINE_FH_LEN]; - unsigned char *ext_fh; - }; -}; +struct fanotify_fh { + unsigned char buf[FANOTIFY_INLINE_FH_LEN]; + u8 type; + u8 len; +} __aligned(4); + +static inline bool fanotify_fh_has_ext_buf(struct fanotify_fh *fh) +{ + return fh->len > FANOTIFY_INLINE_FH_LEN; +} + +static inline char **fanotify_fh_ext_buf_ptr(struct fanotify_fh *fh) +{ + BUILD_BUG_ON(__alignof__(char *) - 4 + sizeof(char *) > + FANOTIFY_INLINE_FH_LEN); + return (char **)ALIGN((unsigned long)(fh->buf), __alignof__(char *)); +} -static inline void *fanotify_fid_fh(struct fanotify_fid *fid, - unsigned int fh_len) +static inline void *fanotify_fh_ext_buf(struct fanotify_fh *fh) { - return fh_len <= FANOTIFY_INLINE_FH_LEN ? fid->fh : fid->ext_fh; + return *fanotify_fh_ext_buf_ptr(fh); } -static inline bool fanotify_fid_equal(struct fanotify_fid *fid1, - struct fanotify_fid *fid2, - unsigned int fh_len) +static inline void *fanotify_fh_buf(struct fanotify_fh *fh) { - return fid1->fsid.val[0] == fid2->fsid.val[0] && - fid1->fsid.val[1] == fid2->fsid.val[1] && - !memcmp(fanotify_fid_fh(fid1, fh_len), - fanotify_fid_fh(fid2, fh_len), fh_len); + return fanotify_fh_has_ext_buf(fh) ? fanotify_fh_ext_buf(fh) : fh->buf; } /* - * Structure for normal fanotify events. It gets allocated in + * Common structure for fanotify events. Concrete structs are allocated in * fanotify_handle_event() and freed when the information is retrieved by - * userspace + * userspace. The type of event determines how it was allocated, how it will + * be freed and which concrete struct it may be cast to. */ +enum fanotify_event_type { + FANOTIFY_EVENT_TYPE_FID, + FANOTIFY_EVENT_TYPE_PATH, + FANOTIFY_EVENT_TYPE_PATH_PERM, +}; + struct fanotify_event { struct fsnotify_event fse; u32 mask; - /* - * Those fields are outside fanotify_fid to pack fanotify_event nicely - * on 64bit arch and to use fh_type as an indication of whether path - * or fid are used in the union: - * FILEID_ROOT (0) for path, > 0 for fid, FILEID_INVALID for neither. - */ - u8 fh_type; - u8 fh_len; - u16 pad; - union { - /* - * We hold ref to this path so it may be dereferenced at any - * point during this object's lifetime - */ - struct path path; - /* - * With FAN_REPORT_FID, we do not hold any reference on the - * victim object. Instead we store its NFS file handle and its - * filesystem's fsid as a unique identifier. - */ - struct fanotify_fid fid; - }; + enum fanotify_event_type type; struct pid *pid; }; -static inline bool fanotify_event_has_path(struct fanotify_event *event) +struct fanotify_fid_event { + struct fanotify_event fae; + __kernel_fsid_t fsid; + struct fanotify_fh object_fh; +}; + +#define FANOTIFY_FE(event) ((struct fanotify_fid_event *)(event)) + +static inline bool fanotify_event_has_fid(struct fanotify_event *event) { - return event->fh_type == FILEID_ROOT; + return event->type == FANOTIFY_EVENT_TYPE_FID; } -static inline bool fanotify_event_has_fid(struct fanotify_event *event) +static inline __kernel_fsid_t *fanotify_event_fsid(struct fanotify_event *event) { - return event->fh_type != FILEID_ROOT && - event->fh_type != FILEID_INVALID; + if (event->type == FANOTIFY_EVENT_TYPE_FID) + return &FANOTIFY_FE(event)->fsid; + else + return NULL; } -static inline bool fanotify_event_has_ext_fh(struct fanotify_event *event) +static inline struct fanotify_fh *fanotify_event_object_fh( + struct fanotify_event *event) { - return fanotify_event_has_fid(event) && - event->fh_len > FANOTIFY_INLINE_FH_LEN; + if (event->type == FANOTIFY_EVENT_TYPE_FID) + return &FANOTIFY_FE(event)->object_fh; + else + return NULL; } -static inline void *fanotify_event_fh(struct fanotify_event *event) +static inline int fanotify_event_object_fh_len(struct fanotify_event *event) { - return fanotify_fid_fh(&event->fid, event->fh_len); + struct fanotify_fh *fh = fanotify_event_object_fh(event); + + return fh ? fh->len : 0; } +struct fanotify_path_event { + struct fanotify_event fae; + struct path path; +}; + +#define FANOTIFY_PE(event) ((struct fanotify_path_event *)(event)) + /* * Structure for permission fanotify events. It gets allocated and freed in * fanotify_handle_event() since we wait there for user response. When the @@ -117,13 +124,14 @@ static inline void *fanotify_event_fh(struct fanotify_event *event) */ struct fanotify_perm_event { struct fanotify_event fae; + struct path path; unsigned short response; /* userspace answer to the event */ unsigned short state; /* state of the event */ int fd; /* fd we passed to userspace for this event */ }; static inline struct fanotify_perm_event * -FANOTIFY_PE(struct fsnotify_event *fse) +FANOTIFY_PERM(struct fsnotify_event *fse) { return container_of(fse, struct fanotify_perm_event, fae.fse); } @@ -139,6 +147,22 @@ static inline struct fanotify_event *FANOTIFY_E(struct fsnotify_event *fse) return container_of(fse, struct fanotify_event, fse); } +static inline bool fanotify_event_has_path(struct fanotify_event *event) +{ + return event->type == FANOTIFY_EVENT_TYPE_PATH || + event->type == FANOTIFY_EVENT_TYPE_PATH_PERM; +} + +static inline struct path *fanotify_event_path(struct fanotify_event *event) +{ + if (event->type == FANOTIFY_EVENT_TYPE_PATH) + return &FANOTIFY_PE(event)->path; + else if (event->type == FANOTIFY_EVENT_TYPE_PATH_PERM) + return &((struct fanotify_perm_event *)event)->path; + else + return NULL; +} + struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, struct inode *inode, u32 mask, const void *data, int data_type, diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 0aa362b88550..6d30627863ff 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -46,18 +46,21 @@ extern const struct fsnotify_ops fanotify_fsnotify_ops; struct kmem_cache *fanotify_mark_cache __read_mostly; -struct kmem_cache *fanotify_event_cachep __read_mostly; +struct kmem_cache *fanotify_fid_event_cachep __read_mostly; +struct kmem_cache *fanotify_path_event_cachep __read_mostly; struct kmem_cache *fanotify_perm_event_cachep __read_mostly; #define FANOTIFY_EVENT_ALIGN 4 static int fanotify_event_info_len(struct fanotify_event *event) { - if (!fanotify_event_has_fid(event)) + int fh_len = fanotify_event_object_fh_len(event); + + if (!fh_len) return 0; return roundup(sizeof(struct fanotify_event_info_fid) + - sizeof(struct file_handle) + event->fh_len, + sizeof(struct file_handle) + fh_len, FANOTIFY_EVENT_ALIGN); } @@ -90,20 +93,19 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group, } fsn_event = fsnotify_remove_first_event(group); if (fanotify_is_perm_event(FANOTIFY_E(fsn_event)->mask)) - FANOTIFY_PE(fsn_event)->state = FAN_EVENT_REPORTED; + FANOTIFY_PERM(fsn_event)->state = FAN_EVENT_REPORTED; out: spin_unlock(&group->notification_lock); return fsn_event; } -static int create_fd(struct fsnotify_group *group, - struct fanotify_event *event, +static int create_fd(struct fsnotify_group *group, struct path *path, struct file **file) { int client_fd; struct file *new_file; - pr_debug("%s: group=%p event=%p\n", __func__, group, event); + pr_debug("%s: group=%p path=%p\n", __func__, group, path); client_fd = get_unused_fd_flags(group->fanotify_data.f_flags); if (client_fd < 0) @@ -113,14 +115,9 @@ static int create_fd(struct fsnotify_group *group, * we need a new file handle for the userspace program so it can read even if it was * originally opened O_WRONLY. */ - /* it's possible this event was an overflow event. in that case dentry and mnt - * are NULL; That's fine, just don't call dentry open */ - if (event->path.dentry && event->path.mnt) - new_file = dentry_open(&event->path, - group->fanotify_data.f_flags | FMODE_NONOTIFY, - current_cred()); - else - new_file = ERR_PTR(-EOVERFLOW); + new_file = dentry_open(path, + group->fanotify_data.f_flags | FMODE_NONOTIFY, + current_cred()); if (IS_ERR(new_file)) { /* * we still send an event even if we can't open the file. this @@ -208,8 +205,9 @@ static int copy_fid_to_user(struct fanotify_event *event, char __user *buf) { struct fanotify_event_info_fid info = { }; struct file_handle handle = { }; - unsigned char bounce[FANOTIFY_INLINE_FH_LEN], *fh; - size_t fh_len = event->fh_len; + unsigned char bounce[FANOTIFY_INLINE_FH_LEN], *fh_buf; + struct fanotify_fh *fh = fanotify_event_object_fh(event); + size_t fh_len = fh->len; size_t len = fanotify_event_info_len(event); if (!len) @@ -221,13 +219,13 @@ static int copy_fid_to_user(struct fanotify_event *event, char __user *buf) /* Copy event info fid header followed by vaiable sized file handle */ info.hdr.info_type = FAN_EVENT_INFO_TYPE_FID; info.hdr.len = len; - info.fsid = event->fid.fsid; + info.fsid = *fanotify_event_fsid(event); if (copy_to_user(buf, &info, sizeof(info))) return -EFAULT; buf += sizeof(info); len -= sizeof(info); - handle.handle_type = event->fh_type; + handle.handle_type = fh->type; handle.handle_bytes = fh_len; if (copy_to_user(buf, &handle, sizeof(handle))) return -EFAULT; @@ -238,12 +236,12 @@ static int copy_fid_to_user(struct fanotify_event *event, char __user *buf) * For an inline fh, copy through stack to exclude the copy from * usercopy hardening protections. */ - fh = fanotify_event_fh(event); + fh_buf = fanotify_fh_buf(fh); if (fh_len <= FANOTIFY_INLINE_FH_LEN) { - memcpy(bounce, fh, fh_len); - fh = bounce; + memcpy(bounce, fh_buf, fh_len); + fh_buf = bounce; } - if (copy_to_user(buf, fh, fh_len)) + if (copy_to_user(buf, fh_buf, fh_len)) return -EFAULT; /* Pad with 0's */ @@ -261,13 +259,13 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, char __user *buf, size_t count) { struct fanotify_event_metadata metadata; - struct fanotify_event *event; + struct fanotify_event *event = FANOTIFY_E(fsn_event); + struct path *path = fanotify_event_path(event); struct file *f = NULL; int ret, fd = FAN_NOFD; pr_debug("%s: group=%p event=%p\n", __func__, group, fsn_event); - event = container_of(fsn_event, struct fanotify_event, fse); metadata.event_len = FAN_EVENT_METADATA_LEN; metadata.metadata_len = FAN_EVENT_METADATA_LEN; metadata.vers = FANOTIFY_METADATA_VERSION; @@ -275,12 +273,12 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, metadata.mask = event->mask & FANOTIFY_OUTGOING_EVENTS; metadata.pid = pid_vnr(event->pid); - if (fanotify_event_has_path(event)) { - fd = create_fd(group, event, &f); + if (fanotify_event_has_fid(event)) { + metadata.event_len += fanotify_event_info_len(event); + } else if (path && path->mnt && path->dentry) { + fd = create_fd(group, path, &f); if (fd < 0) return fd; - } else if (fanotify_event_has_fid(event)) { - metadata.event_len += fanotify_event_info_len(event); } metadata.fd = fd; @@ -296,9 +294,9 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, goto out_close_fd; if (fanotify_is_perm_event(event->mask)) - FANOTIFY_PE(fsn_event)->fd = fd; + FANOTIFY_PERM(fsn_event)->fd = fd; - if (fanotify_event_has_path(event)) { + if (f) { fd_install(fd, f); } else if (fanotify_event_has_fid(event)) { ret = copy_fid_to_user(event, buf + FAN_EVENT_METADATA_LEN); @@ -390,7 +388,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, if (ret <= 0) { spin_lock(&group->notification_lock); finish_permission_event(group, - FANOTIFY_PE(kevent), FAN_DENY); + FANOTIFY_PERM(kevent), FAN_DENY); wake_up(&group->fanotify_data.access_waitq); } else { spin_lock(&group->notification_lock); @@ -474,7 +472,7 @@ static int fanotify_release(struct inode *ignored, struct file *file) spin_unlock(&group->notification_lock); fsnotify_destroy_event(group, fsn_event); } else { - finish_permission_event(group, FANOTIFY_PE(fsn_event), + finish_permission_event(group, FANOTIFY_PERM(fsn_event), FAN_ALLOW); } spin_lock(&group->notification_lock); @@ -1139,7 +1137,10 @@ static int __init fanotify_user_setup(void) fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC|SLAB_ACCOUNT); - fanotify_event_cachep = KMEM_CACHE(fanotify_event, SLAB_PANIC); + fanotify_fid_event_cachep = KMEM_CACHE(fanotify_fid_event, + SLAB_PANIC); + fanotify_path_event_cachep = KMEM_CACHE(fanotify_path_event, + SLAB_PANIC); if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) { fanotify_perm_event_cachep = KMEM_CACHE(fanotify_perm_event, SLAB_PANIC); -- 2.17.1