mirror of
https://github.com/torvalds/linux
synced 2024-09-06 18:01:05 +00:00
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-----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEq1nRK9aeMoq1VSgcnJ2qBz9kQNkFAmEmOoUACgkQnJ2qBz9k QNm8XggA6cbU79idj2HgDG5Wj4X3cd1+NlpPP2HytvTomwqYHJmHPAg0b44AsfHT ToHeYhIqb78MbLHn8fl4g5+O01raqihbUyIcRNcgdeQcle7Phuv/hDlsr8EOhfea mec4vottwaoiNn+4o7ciUAIri0stbVL8VPpnOy0X7iCmX7OC2vUvhQQGwvyfmXZm +F/8jppfvfsxl73SbWhG+sgD83D4ASZ+BGwC1Fx9tHitOVTJzg+CR2C1J4seaK6E r8+u/K6YKSrCGgA2dOVgzYyp2vHPGbHS4Z3H1HDXS+mtqxHJYqPR54kRT1BqCEQX Nm4CP7+u6a+86HLpBZi1NhvYrgLTig== =LJaZ -----END PGP SIGNATURE----- Merge tag 'fsnotify_for_v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fsnotify updates from Jan Kara: "fsnotify speedups when notification actually isn't used and support for identifying processes which caused fanotify events through pidfd instead of normal pid" * tag 'fsnotify_for_v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fsnotify: optimize the case of no marks of any type fsnotify: count all objects with attached connectors fsnotify: count s_fsnotify_inode_refs for attached connectors fsnotify: replace igrab() with ihold() on attach connector fanotify: add pidfd support to the fanotify API fanotify: introduce a generic info record copying helper fanotify: minor cosmetic adjustments to fid labels kernel/pid.c: implement additional checks upon pidfd_create() parameters kernel/pid.c: remove static qualifier from pidfd_create()
This commit is contained in:
commit
3513431926
|
@ -1,6 +1,7 @@
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// SPDX-License-Identifier: GPL-2.0
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#include <linux/fanotify.h>
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#include <linux/fcntl.h>
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#include <linux/fdtable.h>
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#include <linux/file.h>
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#include <linux/fs.h>
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#include <linux/anon_inodes.h>
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@ -109,8 +110,10 @@ struct kmem_cache *fanotify_path_event_cachep __read_mostly;
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struct kmem_cache *fanotify_perm_event_cachep __read_mostly;
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#define FANOTIFY_EVENT_ALIGN 4
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#define FANOTIFY_INFO_HDR_LEN \
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#define FANOTIFY_FID_INFO_HDR_LEN \
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(sizeof(struct fanotify_event_info_fid) + sizeof(struct file_handle))
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#define FANOTIFY_PIDFD_INFO_HDR_LEN \
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sizeof(struct fanotify_event_info_pidfd)
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static int fanotify_fid_info_len(int fh_len, int name_len)
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{
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@ -119,10 +122,11 @@ static int fanotify_fid_info_len(int fh_len, int name_len)
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if (name_len)
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info_len += name_len + 1;
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return roundup(FANOTIFY_INFO_HDR_LEN + info_len, FANOTIFY_EVENT_ALIGN);
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return roundup(FANOTIFY_FID_INFO_HDR_LEN + info_len,
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FANOTIFY_EVENT_ALIGN);
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}
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static int fanotify_event_info_len(unsigned int fid_mode,
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static int fanotify_event_info_len(unsigned int info_mode,
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struct fanotify_event *event)
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{
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struct fanotify_info *info = fanotify_event_info(event);
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@ -133,7 +137,8 @@ static int fanotify_event_info_len(unsigned int fid_mode,
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if (dir_fh_len) {
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info_len += fanotify_fid_info_len(dir_fh_len, info->name_len);
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} else if ((fid_mode & FAN_REPORT_NAME) && (event->mask & FAN_ONDIR)) {
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} else if ((info_mode & FAN_REPORT_NAME) &&
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(event->mask & FAN_ONDIR)) {
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/*
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* With group flag FAN_REPORT_NAME, if name was not recorded in
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* event on a directory, we will report the name ".".
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@ -141,6 +146,9 @@ static int fanotify_event_info_len(unsigned int fid_mode,
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dot_len = 1;
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}
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if (info_mode & FAN_REPORT_PIDFD)
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info_len += FANOTIFY_PIDFD_INFO_HDR_LEN;
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if (fh_len)
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info_len += fanotify_fid_info_len(fh_len, dot_len);
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@ -176,7 +184,7 @@ static struct fanotify_event *get_one_event(struct fsnotify_group *group,
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size_t event_size = FAN_EVENT_METADATA_LEN;
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struct fanotify_event *event = NULL;
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struct fsnotify_event *fsn_event;
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unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
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unsigned int info_mode = FAN_GROUP_FLAG(group, FANOTIFY_INFO_MODES);
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pr_debug("%s: group=%p count=%zd\n", __func__, group, count);
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@ -186,8 +194,8 @@ static struct fanotify_event *get_one_event(struct fsnotify_group *group,
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goto out;
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event = FANOTIFY_E(fsn_event);
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if (fid_mode)
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event_size += fanotify_event_info_len(fid_mode, event);
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if (info_mode)
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event_size += fanotify_event_info_len(info_mode, event);
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if (event_size > count) {
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event = ERR_PTR(-EINVAL);
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|
@ -308,9 +316,10 @@ static int process_access_response(struct fsnotify_group *group,
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return -ENOENT;
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}
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static int copy_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh,
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int info_type, const char *name, size_t name_len,
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char __user *buf, size_t count)
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static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh,
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int info_type, const char *name,
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size_t name_len,
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char __user *buf, size_t count)
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{
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struct fanotify_event_info_fid info = { };
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struct file_handle handle = { };
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@ -403,6 +412,117 @@ static int copy_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh,
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return info_len;
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}
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static int copy_pidfd_info_to_user(int pidfd,
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char __user *buf,
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size_t count)
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{
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struct fanotify_event_info_pidfd info = { };
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size_t info_len = FANOTIFY_PIDFD_INFO_HDR_LEN;
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if (WARN_ON_ONCE(info_len > count))
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return -EFAULT;
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info.hdr.info_type = FAN_EVENT_INFO_TYPE_PIDFD;
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info.hdr.len = info_len;
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info.pidfd = pidfd;
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if (copy_to_user(buf, &info, info_len))
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return -EFAULT;
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return info_len;
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}
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static int copy_info_records_to_user(struct fanotify_event *event,
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struct fanotify_info *info,
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unsigned int info_mode, int pidfd,
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char __user *buf, size_t count)
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{
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int ret, total_bytes = 0, info_type = 0;
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unsigned int fid_mode = info_mode & FANOTIFY_FID_BITS;
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unsigned int pidfd_mode = info_mode & FAN_REPORT_PIDFD;
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/*
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* Event info records order is as follows: dir fid + name, child fid.
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*/
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if (fanotify_event_dir_fh_len(event)) {
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info_type = info->name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME :
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FAN_EVENT_INFO_TYPE_DFID;
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ret = copy_fid_info_to_user(fanotify_event_fsid(event),
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fanotify_info_dir_fh(info),
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info_type,
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fanotify_info_name(info),
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info->name_len, buf, count);
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if (ret < 0)
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return ret;
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buf += ret;
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count -= ret;
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total_bytes += ret;
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}
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if (fanotify_event_object_fh_len(event)) {
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const char *dot = NULL;
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int dot_len = 0;
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if (fid_mode == FAN_REPORT_FID || info_type) {
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/*
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* With only group flag FAN_REPORT_FID only type FID is
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* reported. Second info record type is always FID.
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*/
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info_type = FAN_EVENT_INFO_TYPE_FID;
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} else if ((fid_mode & FAN_REPORT_NAME) &&
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(event->mask & FAN_ONDIR)) {
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/*
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* With group flag FAN_REPORT_NAME, if name was not
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* recorded in an event on a directory, report the name
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* "." with info type DFID_NAME.
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*/
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info_type = FAN_EVENT_INFO_TYPE_DFID_NAME;
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dot = ".";
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dot_len = 1;
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} else if ((event->mask & ALL_FSNOTIFY_DIRENT_EVENTS) ||
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(event->mask & FAN_ONDIR)) {
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/*
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* With group flag FAN_REPORT_DIR_FID, a single info
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* record has type DFID for directory entry modification
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* event and for event on a directory.
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*/
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info_type = FAN_EVENT_INFO_TYPE_DFID;
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} else {
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/*
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* With group flags FAN_REPORT_DIR_FID|FAN_REPORT_FID,
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* a single info record has type FID for event on a
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* non-directory, when there is no directory to report.
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* For example, on FAN_DELETE_SELF event.
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*/
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info_type = FAN_EVENT_INFO_TYPE_FID;
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}
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ret = copy_fid_info_to_user(fanotify_event_fsid(event),
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fanotify_event_object_fh(event),
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info_type, dot, dot_len,
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buf, count);
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if (ret < 0)
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return ret;
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buf += ret;
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count -= ret;
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total_bytes += ret;
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}
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if (pidfd_mode) {
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ret = copy_pidfd_info_to_user(pidfd, buf, count);
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if (ret < 0)
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return ret;
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buf += ret;
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count -= ret;
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total_bytes += ret;
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}
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return total_bytes;
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}
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static ssize_t copy_event_to_user(struct fsnotify_group *group,
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struct fanotify_event *event,
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char __user *buf, size_t count)
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@ -410,15 +530,15 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
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struct fanotify_event_metadata metadata;
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struct path *path = fanotify_event_path(event);
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struct fanotify_info *info = fanotify_event_info(event);
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unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
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unsigned int info_mode = FAN_GROUP_FLAG(group, FANOTIFY_INFO_MODES);
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unsigned int pidfd_mode = info_mode & FAN_REPORT_PIDFD;
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struct file *f = NULL;
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int ret, fd = FAN_NOFD;
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int info_type = 0;
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int ret, pidfd = FAN_NOPIDFD, fd = FAN_NOFD;
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pr_debug("%s: group=%p event=%p\n", __func__, group, event);
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metadata.event_len = FAN_EVENT_METADATA_LEN +
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fanotify_event_info_len(fid_mode, event);
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fanotify_event_info_len(info_mode, event);
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metadata.metadata_len = FAN_EVENT_METADATA_LEN;
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metadata.vers = FANOTIFY_METADATA_VERSION;
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metadata.reserved = 0;
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@ -447,6 +567,33 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
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}
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metadata.fd = fd;
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if (pidfd_mode) {
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/*
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* Complain if the FAN_REPORT_PIDFD and FAN_REPORT_TID mutual
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* exclusion is ever lifted. At the time of incoporating pidfd
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* support within fanotify, the pidfd API only supported the
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* creation of pidfds for thread-group leaders.
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*/
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WARN_ON_ONCE(FAN_GROUP_FLAG(group, FAN_REPORT_TID));
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/*
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* The PIDTYPE_TGID check for an event->pid is performed
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* preemptively in an attempt to catch out cases where the event
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* listener reads events after the event generating process has
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* already terminated. Report FAN_NOPIDFD to the event listener
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* in those cases, with all other pidfd creation errors being
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* reported as FAN_EPIDFD.
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*/
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if (metadata.pid == 0 ||
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!pid_has_task(event->pid, PIDTYPE_TGID)) {
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pidfd = FAN_NOPIDFD;
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} else {
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pidfd = pidfd_create(event->pid, 0);
|
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if (pidfd < 0)
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pidfd = FAN_EPIDFD;
|
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}
|
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}
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|
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ret = -EFAULT;
|
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/*
|
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* Sanity check copy size in case get_one_event() and
|
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|
@ -467,67 +614,11 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
|
|||
if (f)
|
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fd_install(fd, f);
|
||||
|
||||
/* Event info records order is: dir fid + name, child fid */
|
||||
if (fanotify_event_dir_fh_len(event)) {
|
||||
info_type = info->name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME :
|
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FAN_EVENT_INFO_TYPE_DFID;
|
||||
ret = copy_info_to_user(fanotify_event_fsid(event),
|
||||
fanotify_info_dir_fh(info),
|
||||
info_type, fanotify_info_name(info),
|
||||
info->name_len, buf, count);
|
||||
if (info_mode) {
|
||||
ret = copy_info_records_to_user(event, info, info_mode, pidfd,
|
||||
buf, count);
|
||||
if (ret < 0)
|
||||
goto out_close_fd;
|
||||
|
||||
buf += ret;
|
||||
count -= ret;
|
||||
}
|
||||
|
||||
if (fanotify_event_object_fh_len(event)) {
|
||||
const char *dot = NULL;
|
||||
int dot_len = 0;
|
||||
|
||||
if (fid_mode == FAN_REPORT_FID || info_type) {
|
||||
/*
|
||||
* With only group flag FAN_REPORT_FID only type FID is
|
||||
* reported. Second info record type is always FID.
|
||||
*/
|
||||
info_type = FAN_EVENT_INFO_TYPE_FID;
|
||||
} else if ((fid_mode & FAN_REPORT_NAME) &&
|
||||
(event->mask & FAN_ONDIR)) {
|
||||
/*
|
||||
* With group flag FAN_REPORT_NAME, if name was not
|
||||
* recorded in an event on a directory, report the
|
||||
* name "." with info type DFID_NAME.
|
||||
*/
|
||||
info_type = FAN_EVENT_INFO_TYPE_DFID_NAME;
|
||||
dot = ".";
|
||||
dot_len = 1;
|
||||
} else if ((event->mask & ALL_FSNOTIFY_DIRENT_EVENTS) ||
|
||||
(event->mask & FAN_ONDIR)) {
|
||||
/*
|
||||
* With group flag FAN_REPORT_DIR_FID, a single info
|
||||
* record has type DFID for directory entry modification
|
||||
* event and for event on a directory.
|
||||
*/
|
||||
info_type = FAN_EVENT_INFO_TYPE_DFID;
|
||||
} else {
|
||||
/*
|
||||
* With group flags FAN_REPORT_DIR_FID|FAN_REPORT_FID,
|
||||
* a single info record has type FID for event on a
|
||||
* non-directory, when there is no directory to report.
|
||||
* For example, on FAN_DELETE_SELF event.
|
||||
*/
|
||||
info_type = FAN_EVENT_INFO_TYPE_FID;
|
||||
}
|
||||
|
||||
ret = copy_info_to_user(fanotify_event_fsid(event),
|
||||
fanotify_event_object_fh(event),
|
||||
info_type, dot, dot_len, buf, count);
|
||||
if (ret < 0)
|
||||
goto out_close_fd;
|
||||
|
||||
buf += ret;
|
||||
count -= ret;
|
||||
}
|
||||
|
||||
return metadata.event_len;
|
||||
|
@ -537,6 +628,10 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
|
|||
put_unused_fd(fd);
|
||||
fput(f);
|
||||
}
|
||||
|
||||
if (pidfd >= 0)
|
||||
close_fd(pidfd);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
@ -1082,6 +1177,14 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
|
|||
#endif
|
||||
return -EINVAL;
|
||||
|
||||
/*
|
||||
* A pidfd can only be returned for a thread-group leader; thus
|
||||
* FAN_REPORT_PIDFD and FAN_REPORT_TID need to remain mutually
|
||||
* exclusive.
|
||||
*/
|
||||
if ((flags & FAN_REPORT_PIDFD) && (flags & FAN_REPORT_TID))
|
||||
return -EINVAL;
|
||||
|
||||
if (event_f_flags & ~FANOTIFY_INIT_ALL_EVENT_F_BITS)
|
||||
return -EINVAL;
|
||||
|
||||
|
@ -1483,7 +1586,7 @@ static int __init fanotify_user_setup(void)
|
|||
FANOTIFY_DEFAULT_MAX_USER_MARKS);
|
||||
|
||||
BUILD_BUG_ON(FANOTIFY_INIT_FLAGS & FANOTIFY_INTERNAL_GROUP_FLAGS);
|
||||
BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 10);
|
||||
BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 11);
|
||||
BUILD_BUG_ON(HWEIGHT32(FANOTIFY_MARK_FLAGS) != 9);
|
||||
|
||||
fanotify_mark_cache = KMEM_CACHE(fsnotify_mark,
|
||||
|
|
|
@ -87,15 +87,15 @@ static void fsnotify_unmount_inodes(struct super_block *sb)
|
|||
|
||||
if (iput_inode)
|
||||
iput(iput_inode);
|
||||
/* Wait for outstanding inode references from connectors */
|
||||
wait_var_event(&sb->s_fsnotify_inode_refs,
|
||||
!atomic_long_read(&sb->s_fsnotify_inode_refs));
|
||||
}
|
||||
|
||||
void fsnotify_sb_delete(struct super_block *sb)
|
||||
{
|
||||
fsnotify_unmount_inodes(sb);
|
||||
fsnotify_clear_marks_by_sb(sb);
|
||||
/* Wait for outstanding object references from connectors */
|
||||
wait_var_event(&sb->s_fsnotify_connectors,
|
||||
!atomic_long_read(&sb->s_fsnotify_connectors));
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
|
@ -27,6 +27,21 @@ static inline struct super_block *fsnotify_conn_sb(
|
|||
return container_of(conn->obj, struct super_block, s_fsnotify_marks);
|
||||
}
|
||||
|
||||
static inline struct super_block *fsnotify_connector_sb(
|
||||
struct fsnotify_mark_connector *conn)
|
||||
{
|
||||
switch (conn->type) {
|
||||
case FSNOTIFY_OBJ_TYPE_INODE:
|
||||
return fsnotify_conn_inode(conn)->i_sb;
|
||||
case FSNOTIFY_OBJ_TYPE_VFSMOUNT:
|
||||
return fsnotify_conn_mount(conn)->mnt.mnt_sb;
|
||||
case FSNOTIFY_OBJ_TYPE_SB:
|
||||
return fsnotify_conn_sb(conn);
|
||||
default:
|
||||
return NULL;
|
||||
}
|
||||
}
|
||||
|
||||
/* destroy all events sitting in this groups notification queue */
|
||||
extern void fsnotify_flush_notify(struct fsnotify_group *group);
|
||||
|
||||
|
|
|
@ -169,6 +169,37 @@ static void fsnotify_connector_destroy_workfn(struct work_struct *work)
|
|||
}
|
||||
}
|
||||
|
||||
static void fsnotify_get_inode_ref(struct inode *inode)
|
||||
{
|
||||
ihold(inode);
|
||||
atomic_long_inc(&inode->i_sb->s_fsnotify_connectors);
|
||||
}
|
||||
|
||||
static void fsnotify_put_inode_ref(struct inode *inode)
|
||||
{
|
||||
struct super_block *sb = inode->i_sb;
|
||||
|
||||
iput(inode);
|
||||
if (atomic_long_dec_and_test(&sb->s_fsnotify_connectors))
|
||||
wake_up_var(&sb->s_fsnotify_connectors);
|
||||
}
|
||||
|
||||
static void fsnotify_get_sb_connectors(struct fsnotify_mark_connector *conn)
|
||||
{
|
||||
struct super_block *sb = fsnotify_connector_sb(conn);
|
||||
|
||||
if (sb)
|
||||
atomic_long_inc(&sb->s_fsnotify_connectors);
|
||||
}
|
||||
|
||||
static void fsnotify_put_sb_connectors(struct fsnotify_mark_connector *conn)
|
||||
{
|
||||
struct super_block *sb = fsnotify_connector_sb(conn);
|
||||
|
||||
if (sb && atomic_long_dec_and_test(&sb->s_fsnotify_connectors))
|
||||
wake_up_var(&sb->s_fsnotify_connectors);
|
||||
}
|
||||
|
||||
static void *fsnotify_detach_connector_from_object(
|
||||
struct fsnotify_mark_connector *conn,
|
||||
unsigned int *type)
|
||||
|
@ -182,13 +213,13 @@ static void *fsnotify_detach_connector_from_object(
|
|||
if (conn->type == FSNOTIFY_OBJ_TYPE_INODE) {
|
||||
inode = fsnotify_conn_inode(conn);
|
||||
inode->i_fsnotify_mask = 0;
|
||||
atomic_long_inc(&inode->i_sb->s_fsnotify_inode_refs);
|
||||
} else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
|
||||
fsnotify_conn_mount(conn)->mnt_fsnotify_mask = 0;
|
||||
} else if (conn->type == FSNOTIFY_OBJ_TYPE_SB) {
|
||||
fsnotify_conn_sb(conn)->s_fsnotify_mask = 0;
|
||||
}
|
||||
|
||||
fsnotify_put_sb_connectors(conn);
|
||||
rcu_assign_pointer(*(conn->obj), NULL);
|
||||
conn->obj = NULL;
|
||||
conn->type = FSNOTIFY_OBJ_TYPE_DETACHED;
|
||||
|
@ -209,19 +240,12 @@ static void fsnotify_final_mark_destroy(struct fsnotify_mark *mark)
|
|||
/* Drop object reference originally held by a connector */
|
||||
static void fsnotify_drop_object(unsigned int type, void *objp)
|
||||
{
|
||||
struct inode *inode;
|
||||
struct super_block *sb;
|
||||
|
||||
if (!objp)
|
||||
return;
|
||||
/* Currently only inode references are passed to be dropped */
|
||||
if (WARN_ON_ONCE(type != FSNOTIFY_OBJ_TYPE_INODE))
|
||||
return;
|
||||
inode = objp;
|
||||
sb = inode->i_sb;
|
||||
iput(inode);
|
||||
if (atomic_long_dec_and_test(&sb->s_fsnotify_inode_refs))
|
||||
wake_up_var(&sb->s_fsnotify_inode_refs);
|
||||
fsnotify_put_inode_ref(objp);
|
||||
}
|
||||
|
||||
void fsnotify_put_mark(struct fsnotify_mark *mark)
|
||||
|
@ -493,8 +517,12 @@ static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp,
|
|||
conn->fsid.val[0] = conn->fsid.val[1] = 0;
|
||||
conn->flags = 0;
|
||||
}
|
||||
if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
|
||||
inode = igrab(fsnotify_conn_inode(conn));
|
||||
if (conn->type == FSNOTIFY_OBJ_TYPE_INODE) {
|
||||
inode = fsnotify_conn_inode(conn);
|
||||
fsnotify_get_inode_ref(inode);
|
||||
}
|
||||
fsnotify_get_sb_connectors(conn);
|
||||
|
||||
/*
|
||||
* cmpxchg() provides the barrier so that readers of *connp can see
|
||||
* only initialized structure
|
||||
|
@ -502,7 +530,7 @@ static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp,
|
|||
if (cmpxchg(connp, NULL, conn)) {
|
||||
/* Someone else created list structure for us */
|
||||
if (inode)
|
||||
iput(inode);
|
||||
fsnotify_put_inode_ref(inode);
|
||||
kmem_cache_free(fsnotify_mark_connector_cachep, conn);
|
||||
}
|
||||
|
||||
|
|
|
@ -27,6 +27,8 @@ extern struct ctl_table fanotify_table[]; /* for sysctl */
|
|||
|
||||
#define FANOTIFY_FID_BITS (FAN_REPORT_FID | FAN_REPORT_DFID_NAME)
|
||||
|
||||
#define FANOTIFY_INFO_MODES (FANOTIFY_FID_BITS | FAN_REPORT_PIDFD)
|
||||
|
||||
/*
|
||||
* fanotify_init() flags that require CAP_SYS_ADMIN.
|
||||
* We do not allow unprivileged groups to request permission events.
|
||||
|
@ -35,6 +37,7 @@ extern struct ctl_table fanotify_table[]; /* for sysctl */
|
|||
*/
|
||||
#define FANOTIFY_ADMIN_INIT_FLAGS (FANOTIFY_PERM_CLASSES | \
|
||||
FAN_REPORT_TID | \
|
||||
FAN_REPORT_PIDFD | \
|
||||
FAN_UNLIMITED_QUEUE | \
|
||||
FAN_UNLIMITED_MARKS)
|
||||
|
||||
|
|
|
@ -1507,8 +1507,11 @@ struct super_block {
|
|||
/* Number of inodes with nlink == 0 but still referenced */
|
||||
atomic_long_t s_remove_count;
|
||||
|
||||
/* Pending fsnotify inode refs */
|
||||
atomic_long_t s_fsnotify_inode_refs;
|
||||
/*
|
||||
* Number of inode/mount/sb objects that are being watched, note that
|
||||
* inodes objects are currently double-accounted.
|
||||
*/
|
||||
atomic_long_t s_fsnotify_connectors;
|
||||
|
||||
/* Being remounted read-only */
|
||||
int s_readonly_remount;
|
||||
|
|
|
@ -30,6 +30,9 @@ static inline void fsnotify_name(struct inode *dir, __u32 mask,
|
|||
struct inode *child,
|
||||
const struct qstr *name, u32 cookie)
|
||||
{
|
||||
if (atomic_long_read(&dir->i_sb->s_fsnotify_connectors) == 0)
|
||||
return;
|
||||
|
||||
fsnotify(mask, child, FSNOTIFY_EVENT_INODE, dir, name, NULL, cookie);
|
||||
}
|
||||
|
||||
|
@ -41,6 +44,9 @@ static inline void fsnotify_dirent(struct inode *dir, struct dentry *dentry,
|
|||
|
||||
static inline void fsnotify_inode(struct inode *inode, __u32 mask)
|
||||
{
|
||||
if (atomic_long_read(&inode->i_sb->s_fsnotify_connectors) == 0)
|
||||
return;
|
||||
|
||||
if (S_ISDIR(inode->i_mode))
|
||||
mask |= FS_ISDIR;
|
||||
|
||||
|
@ -53,6 +59,9 @@ static inline int fsnotify_parent(struct dentry *dentry, __u32 mask,
|
|||
{
|
||||
struct inode *inode = d_inode(dentry);
|
||||
|
||||
if (atomic_long_read(&inode->i_sb->s_fsnotify_connectors) == 0)
|
||||
return 0;
|
||||
|
||||
if (S_ISDIR(inode->i_mode)) {
|
||||
mask |= FS_ISDIR;
|
||||
|
||||
|
|
|
@ -78,6 +78,7 @@ struct file;
|
|||
|
||||
extern struct pid *pidfd_pid(const struct file *file);
|
||||
struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags);
|
||||
int pidfd_create(struct pid *pid, unsigned int flags);
|
||||
|
||||
static inline struct pid *get_pid(struct pid *pid)
|
||||
{
|
||||
|
|
|
@ -51,6 +51,7 @@
|
|||
#define FAN_ENABLE_AUDIT 0x00000040
|
||||
|
||||
/* Flags to determine fanotify event format */
|
||||
#define FAN_REPORT_PIDFD 0x00000080 /* Report pidfd for event->pid */
|
||||
#define FAN_REPORT_TID 0x00000100 /* event->pid is thread id */
|
||||
#define FAN_REPORT_FID 0x00000200 /* Report unique file id */
|
||||
#define FAN_REPORT_DIR_FID 0x00000400 /* Report unique directory id */
|
||||
|
@ -123,6 +124,7 @@ struct fanotify_event_metadata {
|
|||
#define FAN_EVENT_INFO_TYPE_FID 1
|
||||
#define FAN_EVENT_INFO_TYPE_DFID_NAME 2
|
||||
#define FAN_EVENT_INFO_TYPE_DFID 3
|
||||
#define FAN_EVENT_INFO_TYPE_PIDFD 4
|
||||
|
||||
/* Variable length info record following event metadata */
|
||||
struct fanotify_event_info_header {
|
||||
|
@ -148,6 +150,15 @@ struct fanotify_event_info_fid {
|
|||
unsigned char handle[0];
|
||||
};
|
||||
|
||||
/*
|
||||
* This structure is used for info records of type FAN_EVENT_INFO_TYPE_PIDFD.
|
||||
* It holds a pidfd for the pid that was responsible for generating an event.
|
||||
*/
|
||||
struct fanotify_event_info_pidfd {
|
||||
struct fanotify_event_info_header hdr;
|
||||
__s32 pidfd;
|
||||
};
|
||||
|
||||
struct fanotify_response {
|
||||
__s32 fd;
|
||||
__u32 response;
|
||||
|
@ -160,6 +171,8 @@ struct fanotify_response {
|
|||
|
||||
/* No fd set in event */
|
||||
#define FAN_NOFD -1
|
||||
#define FAN_NOPIDFD FAN_NOFD
|
||||
#define FAN_EPIDFD -2
|
||||
|
||||
/* Helper functions to deal with fanotify_event_metadata buffers */
|
||||
#define FAN_EVENT_METADATA_LEN (sizeof(struct fanotify_event_metadata))
|
||||
|
|
15
kernel/pid.c
15
kernel/pid.c
|
@ -550,13 +550,21 @@ struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags)
|
|||
* Note, that this function can only be called after the fd table has
|
||||
* been unshared to avoid leaking the pidfd to the new process.
|
||||
*
|
||||
* This symbol should not be explicitly exported to loadable modules.
|
||||
*
|
||||
* Return: On success, a cloexec pidfd is returned.
|
||||
* On error, a negative errno number will be returned.
|
||||
*/
|
||||
static int pidfd_create(struct pid *pid, unsigned int flags)
|
||||
int pidfd_create(struct pid *pid, unsigned int flags)
|
||||
{
|
||||
int fd;
|
||||
|
||||
if (!pid || !pid_has_task(pid, PIDTYPE_TGID))
|
||||
return -EINVAL;
|
||||
|
||||
if (flags & ~(O_NONBLOCK | O_RDWR | O_CLOEXEC))
|
||||
return -EINVAL;
|
||||
|
||||
fd = anon_inode_getfd("[pidfd]", &pidfd_fops, get_pid(pid),
|
||||
flags | O_RDWR | O_CLOEXEC);
|
||||
if (fd < 0)
|
||||
|
@ -596,10 +604,7 @@ SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)
|
|||
if (!p)
|
||||
return -ESRCH;
|
||||
|
||||
if (pid_has_task(p, PIDTYPE_TGID))
|
||||
fd = pidfd_create(p, flags);
|
||||
else
|
||||
fd = -EINVAL;
|
||||
fd = pidfd_create(p, flags);
|
||||
|
||||
put_pid(p);
|
||||
return fd;
|
||||
|
|
Loading…
Reference in a new issue