From d3424c9bac893bd06f38a20474cd622881d384ca Mon Sep 17 00:00:00 2001 From: Matthew Bobrowski Date: Sun, 8 Aug 2021 15:25:32 +1000 Subject: fanotify: minor cosmetic adjustments to fid labels With the idea to support additional info record types in the future i.e. fanotify_event_info_pidfd, it's a good idea to rename some of the labels assigned to some of the existing fid related functions, parameters, etc which more accurately represent the intent behind their usage. For example, copy_info_to_user() was defined with a generic function label, which arguably reads as being supportive of different info record types, however the parameter list for this function is explicitly tailored towards the creation and copying of the fanotify_event_info_fid records. This same point applies to the macro defined as FANOTIFY_INFO_HDR_LEN. With fanotify_event_info_len(), we change the parameter label so that the function implies that it can be extended to calculate the length for additional info record types. Link: https://lore.kernel.org/r/7c3ec33f3c718dac40764305d4d494d858f59c51.1628398044.git.repnop@google.com Signed-off-by: Matthew Bobrowski Reviewed-by: Amir Goldstein Signed-off-by: Jan Kara --- fs/notify/fanotify/fanotify_user.c | 33 +++++++++++++++++++-------------- 1 file changed, 19 insertions(+), 14 deletions(-) (limited to 'fs/notify/fanotify') diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 64864fb40b40..182fea255376 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -104,7 +104,7 @@ struct kmem_cache *fanotify_path_event_cachep __read_mostly; struct kmem_cache *fanotify_perm_event_cachep __read_mostly; #define FANOTIFY_EVENT_ALIGN 4 -#define FANOTIFY_INFO_HDR_LEN \ +#define FANOTIFY_FID_INFO_HDR_LEN \ (sizeof(struct fanotify_event_info_fid) + sizeof(struct file_handle)) static int fanotify_fid_info_len(int fh_len, int name_len) @@ -114,10 +114,11 @@ static int fanotify_fid_info_len(int fh_len, int name_len) if (name_len) info_len += name_len + 1; - return roundup(FANOTIFY_INFO_HDR_LEN + info_len, FANOTIFY_EVENT_ALIGN); + return roundup(FANOTIFY_FID_INFO_HDR_LEN + info_len, + FANOTIFY_EVENT_ALIGN); } -static int fanotify_event_info_len(unsigned int fid_mode, +static int fanotify_event_info_len(unsigned int info_mode, struct fanotify_event *event) { struct fanotify_info *info = fanotify_event_info(event); @@ -128,7 +129,8 @@ static int fanotify_event_info_len(unsigned int fid_mode, if (dir_fh_len) { info_len += fanotify_fid_info_len(dir_fh_len, info->name_len); - } else if ((fid_mode & FAN_REPORT_NAME) && (event->mask & FAN_ONDIR)) { + } else if ((info_mode & FAN_REPORT_NAME) && + (event->mask & FAN_ONDIR)) { /* * With group flag FAN_REPORT_NAME, if name was not recorded in * event on a directory, we will report the name ".". @@ -303,9 +305,10 @@ static int process_access_response(struct fsnotify_group *group, return -ENOENT; } -static int copy_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh, - int info_type, const char *name, size_t name_len, - char __user *buf, size_t count) +static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh, + int info_type, const char *name, + size_t name_len, + char __user *buf, size_t count) { struct fanotify_event_info_fid info = { }; struct file_handle handle = { }; @@ -466,10 +469,11 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, if (fanotify_event_dir_fh_len(event)) { info_type = info->name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME : 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); + ret = copy_fid_info_to_user(fanotify_event_fsid(event), + fanotify_info_dir_fh(info), + info_type, + fanotify_info_name(info), + info->name_len, buf, count); if (ret < 0) goto out_close_fd; @@ -515,9 +519,10 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, 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); + ret = copy_fid_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; -- cgit v1.2.3 From 0aca67bb7f0d8c997dfef8ff0bfeb0afb361f0e6 Mon Sep 17 00:00:00 2001 From: Matthew Bobrowski Date: Sun, 8 Aug 2021 15:25:58 +1000 Subject: fanotify: introduce a generic info record copying helper The copy_info_records_to_user() helper allows for the separation of info record copying routines/conditionals from copy_event_to_user(), which reduces the overall clutter within this function. This becomes especially true as we start introducing additional info records in the future i.e. struct fanotify_event_info_pidfd. On success, this helper returns the total amount of bytes that have been copied into the user supplied buffer and on error, a negative value is returned to the caller. The newly defined macro FANOTIFY_INFO_MODES can be used to obtain info record types that have been enabled for a specific notification group. This macro becomes useful in the subsequent patch when the FAN_REPORT_PIDFD initialization flag is introduced. Link: https://lore.kernel.org/r/8872947dfe12ce8ae6e9a7f2d49ea29bc8006af0.1628398044.git.repnop@google.com Signed-off-by: Matthew Bobrowski Reviewed-by: Amir Goldstein Signed-off-by: Jan Kara --- fs/notify/fanotify/fanotify_user.c | 155 +++++++++++++++++++++---------------- include/linux/fanotify.h | 2 + 2 files changed, 90 insertions(+), 67 deletions(-) (limited to 'fs/notify/fanotify') diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 182fea255376..99d145eaab49 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -173,7 +173,7 @@ static struct fanotify_event *get_one_event(struct fsnotify_group *group, size_t event_size = FAN_EVENT_METADATA_LEN; struct fanotify_event *event = NULL; struct fsnotify_event *fsn_event; - unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS); + unsigned int info_mode = FAN_GROUP_FLAG(group, FANOTIFY_INFO_MODES); pr_debug("%s: group=%p count=%zd\n", __func__, group, count); @@ -183,8 +183,8 @@ static struct fanotify_event *get_one_event(struct fsnotify_group *group, goto out; event = FANOTIFY_E(fsn_event); - if (fid_mode) - event_size += fanotify_event_info_len(fid_mode, event); + if (info_mode) + event_size += fanotify_event_info_len(info_mode, event); if (event_size > count) { event = ERR_PTR(-EINVAL); @@ -401,6 +401,86 @@ static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh, return info_len; } +static int copy_info_records_to_user(struct fanotify_event *event, + struct fanotify_info *info, + unsigned int info_mode, + char __user *buf, size_t count) +{ + int ret, total_bytes = 0, info_type = 0; + unsigned int fid_mode = info_mode & FANOTIFY_FID_BITS; + + /* + * Event info records order is as follows: dir fid + name, child fid. + */ + if (fanotify_event_dir_fh_len(event)) { + info_type = info->name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME : + FAN_EVENT_INFO_TYPE_DFID; + ret = copy_fid_info_to_user(fanotify_event_fsid(event), + fanotify_info_dir_fh(info), + info_type, + fanotify_info_name(info), + info->name_len, buf, count); + if (ret < 0) + return ret; + + buf += ret; + count -= ret; + total_bytes += 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_fid_info_to_user(fanotify_event_fsid(event), + fanotify_event_object_fh(event), + info_type, dot, dot_len, + buf, count); + if (ret < 0) + return ret; + + buf += ret; + count -= ret; + total_bytes += ret; + } + + return total_bytes; +} + static ssize_t copy_event_to_user(struct fsnotify_group *group, struct fanotify_event *event, char __user *buf, size_t count) @@ -408,15 +488,14 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, struct fanotify_event_metadata metadata; struct path *path = fanotify_event_path(event); struct fanotify_info *info = fanotify_event_info(event); - unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS); + unsigned int info_mode = FAN_GROUP_FLAG(group, FANOTIFY_INFO_MODES); struct file *f = NULL; int ret, fd = FAN_NOFD; - int info_type = 0; pr_debug("%s: group=%p event=%p\n", __func__, group, event); metadata.event_len = FAN_EVENT_METADATA_LEN + - fanotify_event_info_len(fid_mode, event); + fanotify_event_info_len(info_mode, event); metadata.metadata_len = FAN_EVENT_METADATA_LEN; metadata.vers = FANOTIFY_METADATA_VERSION; metadata.reserved = 0; @@ -465,69 +544,11 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, if (f) 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 : - FAN_EVENT_INFO_TYPE_DFID; - ret = copy_fid_info_to_user(fanotify_event_fsid(event), - fanotify_info_dir_fh(info), - info_type, - fanotify_info_name(info), - info->name_len, 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_fid_info_to_user(fanotify_event_fsid(event), - fanotify_event_object_fh(event), - info_type, dot, dot_len, - buf, count); + if (info_mode) { + ret = copy_info_records_to_user(event, info, info_mode, + buf, count); if (ret < 0) goto out_close_fd; - - buf += ret; - count -= ret; } return metadata.event_len; diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h index a16dbeced152..10a7e26ddba6 100644 --- a/include/linux/fanotify.h +++ b/include/linux/fanotify.h @@ -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) + /* * fanotify_init() flags that require CAP_SYS_ADMIN. * We do not allow unprivileged groups to request permission events. -- cgit v1.2.3 From af579beb666aefb17e9a335c12c788c92932baf1 Mon Sep 17 00:00:00 2001 From: Matthew Bobrowski Date: Sun, 8 Aug 2021 15:26:25 +1000 Subject: fanotify: add pidfd support to the fanotify API Introduce a new flag FAN_REPORT_PIDFD for fanotify_init(2) which allows userspace applications to control whether a pidfd information record containing a pidfd is to be returned alongside the generic event metadata for each event. If FAN_REPORT_PIDFD is enabled for a notification group, an additional struct fanotify_event_info_pidfd object type will be supplied alongside the generic struct fanotify_event_metadata for a single event. This functionality is analogous to that of FAN_REPORT_FID in terms of how the event structure is supplied to a userspace application. Usage of FAN_REPORT_PIDFD with FAN_REPORT_FID/FAN_REPORT_DFID_NAME is permitted, and in this case a struct fanotify_event_info_pidfd object will likely follow any struct fanotify_event_info_fid object. Currently, the usage of the FAN_REPORT_TID flag is not permitted along with FAN_REPORT_PIDFD as the pidfd API currently only supports the creation of pidfds for thread-group leaders. Additionally, usage of the FAN_REPORT_PIDFD flag is limited to privileged processes only i.e. event listeners that are running with the CAP_SYS_ADMIN capability. Attempting to supply the FAN_REPORT_TID initialization flags with FAN_REPORT_PIDFD or creating a notification group without CAP_SYS_ADMIN will result with -EINVAL being returned to the caller. In the event of a pidfd creation error, there are two types of error values that can be reported back to the listener. There is FAN_NOPIDFD, which will be reported in cases where the process responsible for generating the event has terminated prior to the event listener being able to read the event. Then there is FAN_EPIDFD, which will be reported when a more generic pidfd creation error has occurred when fanotify calls pidfd_create(). Link: https://lore.kernel.org/r/5f9e09cff7ed62bfaa51c1369e0f7ea5f16a91aa.1628398044.git.repnop@google.com Signed-off-by: Matthew Bobrowski Signed-off-by: Jan Kara --- fs/notify/fanotify/fanotify_user.c | 85 ++++++++++++++++++++++++++++++++++++-- include/linux/fanotify.h | 3 +- include/uapi/linux/fanotify.h | 13 ++++++ 3 files changed, 96 insertions(+), 5 deletions(-) (limited to 'fs/notify/fanotify') diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 99d145eaab49..084a83b1214d 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include #include +#include #include #include #include @@ -106,6 +107,8 @@ struct kmem_cache *fanotify_perm_event_cachep __read_mostly; #define FANOTIFY_EVENT_ALIGN 4 #define FANOTIFY_FID_INFO_HDR_LEN \ (sizeof(struct fanotify_event_info_fid) + sizeof(struct file_handle)) +#define FANOTIFY_PIDFD_INFO_HDR_LEN \ + sizeof(struct fanotify_event_info_pidfd) static int fanotify_fid_info_len(int fh_len, int name_len) { @@ -138,6 +141,9 @@ static int fanotify_event_info_len(unsigned int info_mode, dot_len = 1; } + if (info_mode & FAN_REPORT_PIDFD) + info_len += FANOTIFY_PIDFD_INFO_HDR_LEN; + if (fh_len) info_len += fanotify_fid_info_len(fh_len, dot_len); @@ -401,13 +407,34 @@ static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh, return info_len; } +static int copy_pidfd_info_to_user(int pidfd, + char __user *buf, + size_t count) +{ + struct fanotify_event_info_pidfd info = { }; + size_t info_len = FANOTIFY_PIDFD_INFO_HDR_LEN; + + if (WARN_ON_ONCE(info_len > count)) + return -EFAULT; + + info.hdr.info_type = FAN_EVENT_INFO_TYPE_PIDFD; + info.hdr.len = info_len; + info.pidfd = pidfd; + + if (copy_to_user(buf, &info, info_len)) + return -EFAULT; + + return info_len; +} + static int copy_info_records_to_user(struct fanotify_event *event, struct fanotify_info *info, - unsigned int info_mode, + unsigned int info_mode, int pidfd, char __user *buf, size_t count) { int ret, total_bytes = 0, info_type = 0; unsigned int fid_mode = info_mode & FANOTIFY_FID_BITS; + unsigned int pidfd_mode = info_mode & FAN_REPORT_PIDFD; /* * Event info records order is as follows: dir fid + name, child fid. @@ -478,6 +505,16 @@ static int copy_info_records_to_user(struct fanotify_event *event, total_bytes += ret; } + if (pidfd_mode) { + ret = copy_pidfd_info_to_user(pidfd, buf, count); + if (ret < 0) + return ret; + + buf += ret; + count -= ret; + total_bytes += ret; + } + return total_bytes; } @@ -489,8 +526,9 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, struct path *path = fanotify_event_path(event); struct fanotify_info *info = fanotify_event_info(event); unsigned int info_mode = FAN_GROUP_FLAG(group, FANOTIFY_INFO_MODES); + unsigned int pidfd_mode = info_mode & FAN_REPORT_PIDFD; struct file *f = NULL; - int ret, fd = FAN_NOFD; + int ret, pidfd = FAN_NOPIDFD, fd = FAN_NOFD; pr_debug("%s: group=%p event=%p\n", __func__, group, event); @@ -524,6 +562,33 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, } metadata.fd = fd; + if (pidfd_mode) { + /* + * Complain if the FAN_REPORT_PIDFD and FAN_REPORT_TID mutual + * exclusion is ever lifted. At the time of incoporating pidfd + * support within fanotify, the pidfd API only supported the + * creation of pidfds for thread-group leaders. + */ + WARN_ON_ONCE(FAN_GROUP_FLAG(group, FAN_REPORT_TID)); + + /* + * The PIDTYPE_TGID check for an event->pid is performed + * preemptively in an attempt to catch out cases where the event + * listener reads events after the event generating process has + * already terminated. Report FAN_NOPIDFD to the event listener + * in those cases, with all other pidfd creation errors being + * reported as FAN_EPIDFD. + */ + if (metadata.pid == 0 || + !pid_has_task(event->pid, PIDTYPE_TGID)) { + pidfd = FAN_NOPIDFD; + } else { + pidfd = pidfd_create(event->pid, 0); + if (pidfd < 0) + pidfd = FAN_EPIDFD; + } + } + ret = -EFAULT; /* * Sanity check copy size in case get_one_event() and @@ -545,7 +610,7 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, fd_install(fd, f); if (info_mode) { - ret = copy_info_records_to_user(event, info, info_mode, + ret = copy_info_records_to_user(event, info, info_mode, pidfd, buf, count); if (ret < 0) goto out_close_fd; @@ -558,6 +623,10 @@ out_close_fd: put_unused_fd(fd); fput(f); } + + if (pidfd >= 0) + close_fd(pidfd); + return ret; } @@ -1103,6 +1172,14 @@ 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; @@ -1504,7 +1581,7 @@ 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, diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h index 10a7e26ddba6..eec3b7c40811 100644 --- a/include/linux/fanotify.h +++ b/include/linux/fanotify.h @@ -27,7 +27,7 @@ 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) +#define FANOTIFY_INFO_MODES (FANOTIFY_FID_BITS | FAN_REPORT_PIDFD) /* * fanotify_init() flags that require CAP_SYS_ADMIN. @@ -37,6 +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) diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h index fbf9c5c7dd59..64553df9d735 100644 --- a/include/uapi/linux/fanotify.h +++ b/include/uapi/linux/fanotify.h @@ -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)) -- cgit v1.2.3