kernel_samsung_a53x/include/linux/fanotify.h

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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_FANOTIFY_H
#define _LINUX_FANOTIFY_H
fanotify: configurable limits via sysfs [ Upstream commit 5b8fea65d197f408bb00b251c70d842826d6b70b ] fanotify has some hardcoded limits. The only APIs to escape those limits are FAN_UNLIMITED_QUEUE and FAN_UNLIMITED_MARKS. Allow finer grained tuning of the system limits via sysfs tunables under /proc/sys/fs/fanotify, similar to tunables under /proc/sys/fs/inotify, with some minor differences. - max_queued_events - global system tunable for group queue size limit. Like the inotify tunable with the same name, it defaults to 16384 and applies on initialization of a new group. - max_user_marks - user ns tunable for marks limit per user. Like the inotify tunable named max_user_watches, on a machine with sufficient RAM and it defaults to 1048576 in init userns and can be further limited per containing user ns. - max_user_groups - user ns tunable for number of groups per user. Like the inotify tunable named max_user_instances, it defaults to 128 in init userns and can be further limited per containing user ns. The slightly different tunable names used for fanotify are derived from the "group" and "mark" terminology used in the fanotify man pages and throughout the code. Considering the fact that the default value for max_user_instances was increased in kernel v5.10 from 8192 to 1048576, leaving the legacy fanotify limit of 8192 marks per group in addition to the max_user_marks limit makes little sense, so the per group marks limit has been removed. Note that when a group is initialized with FAN_UNLIMITED_MARKS, its own marks are not accounted in the per user marks account, so in effect the limit of max_user_marks is only for the collection of groups that are not initialized with FAN_UNLIMITED_MARKS. Link: https://lore.kernel.org/r/20210304112921.3996419-2-amir73il@gmail.com Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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#include <linux/sysctl.h>
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#include <uapi/linux/fanotify.h>
fanotify: configurable limits via sysfs [ Upstream commit 5b8fea65d197f408bb00b251c70d842826d6b70b ] fanotify has some hardcoded limits. The only APIs to escape those limits are FAN_UNLIMITED_QUEUE and FAN_UNLIMITED_MARKS. Allow finer grained tuning of the system limits via sysfs tunables under /proc/sys/fs/fanotify, similar to tunables under /proc/sys/fs/inotify, with some minor differences. - max_queued_events - global system tunable for group queue size limit. Like the inotify tunable with the same name, it defaults to 16384 and applies on initialization of a new group. - max_user_marks - user ns tunable for marks limit per user. Like the inotify tunable named max_user_watches, on a machine with sufficient RAM and it defaults to 1048576 in init userns and can be further limited per containing user ns. - max_user_groups - user ns tunable for number of groups per user. Like the inotify tunable named max_user_instances, it defaults to 128 in init userns and can be further limited per containing user ns. The slightly different tunable names used for fanotify are derived from the "group" and "mark" terminology used in the fanotify man pages and throughout the code. Considering the fact that the default value for max_user_instances was increased in kernel v5.10 from 8192 to 1048576, leaving the legacy fanotify limit of 8192 marks per group in addition to the max_user_marks limit makes little sense, so the per group marks limit has been removed. Note that when a group is initialized with FAN_UNLIMITED_MARKS, its own marks are not accounted in the per user marks account, so in effect the limit of max_user_marks is only for the collection of groups that are not initialized with FAN_UNLIMITED_MARKS. Link: https://lore.kernel.org/r/20210304112921.3996419-2-amir73il@gmail.com Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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extern struct ctl_table fanotify_table[]; /* for sysctl */
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#define FAN_GROUP_FLAG(group, flag) \
((group)->fanotify_data.flags & (flag))
/*
* Flags allowed to be passed from/to userspace.
*
* We intentionally do not add new bits to the old FAN_ALL_* constants, because
* they are uapi exposed constants. If there are programs out there using
* these constant, the programs may break if re-compiled with new uapi headers
* and then run on an old kernel.
*/
/* Group classes where permission events are allowed */
#define FANOTIFY_PERM_CLASSES (FAN_CLASS_CONTENT | \
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FAN_CLASS_PRE_CONTENT)
#define FANOTIFY_CLASS_BITS (FAN_CLASS_NOTIF | FANOTIFY_PERM_CLASSES)
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#define FANOTIFY_FID_BITS (FAN_REPORT_FID | FAN_REPORT_DFID_NAME)
fanotify: add pidfd support to the fanotify API [ Upstream commit af579beb666aefb17e9a335c12c788c92932baf1 ] 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 <repnop@google.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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#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.
* We do not allow unprivileged groups to get other process pid in events.
* We do not allow unprivileged groups to use unlimited resources.
*/
#define FANOTIFY_ADMIN_INIT_FLAGS (FANOTIFY_PERM_CLASSES | \
FAN_REPORT_TID | \
fanotify: add pidfd support to the fanotify API [ Upstream commit af579beb666aefb17e9a335c12c788c92932baf1 ] 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 <repnop@google.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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FAN_REPORT_PIDFD | \
FAN_UNLIMITED_QUEUE | \
FAN_UNLIMITED_MARKS)
/*
* fanotify_init() flags that are allowed for user without CAP_SYS_ADMIN.
* FAN_CLASS_NOTIF is the only class we allow for unprivileged group.
* We do not allow unprivileged groups to get file descriptors in events,
* so one of the flags for reporting file handles is required.
*/
#define FANOTIFY_USER_INIT_FLAGS (FAN_CLASS_NOTIF | \
FANOTIFY_FID_BITS | \
FAN_CLOEXEC | FAN_NONBLOCK)
#define FANOTIFY_INIT_FLAGS (FANOTIFY_ADMIN_INIT_FLAGS | \
FANOTIFY_USER_INIT_FLAGS)
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/* Internal group flags */
#define FANOTIFY_UNPRIV 0x80000000
#define FANOTIFY_INTERNAL_GROUP_FLAGS (FANOTIFY_UNPRIV)
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#define FANOTIFY_MARK_TYPE_BITS (FAN_MARK_INODE | FAN_MARK_MOUNT | \
FAN_MARK_FILESYSTEM)
#define FANOTIFY_MARK_FLAGS (FANOTIFY_MARK_TYPE_BITS | \
FAN_MARK_ADD | \
FAN_MARK_REMOVE | \
FAN_MARK_DONT_FOLLOW | \
FAN_MARK_ONLYDIR | \
FAN_MARK_IGNORED_MASK | \
FAN_MARK_IGNORED_SURV_MODIFY | \
FAN_MARK_FLUSH)
/*
* Events that can be reported with data type FSNOTIFY_EVENT_PATH.
* Note that FAN_MODIFY can also be reported with data type
* FSNOTIFY_EVENT_INODE.
*/
#define FANOTIFY_PATH_EVENTS (FAN_ACCESS | FAN_MODIFY | \
FAN_CLOSE | FAN_OPEN | FAN_OPEN_EXEC)
/*
* Directory entry modification events - reported only to directory
* where entry is modified and not to a watching parent.
*/
#define FANOTIFY_DIRENT_EVENTS (FAN_MOVE | FAN_CREATE | FAN_DELETE)
/* Events that can be reported with event->fd */
#define FANOTIFY_FD_EVENTS (FANOTIFY_PATH_EVENTS | FANOTIFY_PERM_EVENTS)
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/* Events that can only be reported with data type FSNOTIFY_EVENT_INODE */
#define FANOTIFY_INODE_EVENTS (FANOTIFY_DIRENT_EVENTS | \
FAN_ATTRIB | FAN_MOVE_SELF | FAN_DELETE_SELF)
/* Events that can only be reported with data type FSNOTIFY_EVENT_ERROR */
#define FANOTIFY_ERROR_EVENTS (FAN_FS_ERROR)
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/* Events that user can request to be notified on */
#define FANOTIFY_EVENTS (FANOTIFY_PATH_EVENTS | \
FANOTIFY_INODE_EVENTS | \
FANOTIFY_ERROR_EVENTS)
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/* Events that require a permission response from user */
#define FANOTIFY_PERM_EVENTS (FAN_OPEN_PERM | FAN_ACCESS_PERM | \
FAN_OPEN_EXEC_PERM)
/* Extra flags that may be reported with event or control handling of events */
#define FANOTIFY_EVENT_FLAGS (FAN_EVENT_ON_CHILD | FAN_ONDIR)
/* Events that may be reported to user */
#define FANOTIFY_OUTGOING_EVENTS (FANOTIFY_EVENTS | \
FANOTIFY_PERM_EVENTS | \
FAN_Q_OVERFLOW | FAN_ONDIR)
#define ALL_FANOTIFY_EVENT_BITS (FANOTIFY_OUTGOING_EVENTS | \
FANOTIFY_EVENT_FLAGS)
/* Do not use these old uapi constants internally */
#undef FAN_ALL_CLASS_BITS
#undef FAN_ALL_INIT_FLAGS
#undef FAN_ALL_MARK_FLAGS
#undef FAN_ALL_EVENTS
#undef FAN_ALL_PERM_EVENTS
#undef FAN_ALL_OUTGOING_EVENTS
#endif /* _LINUX_FANOTIFY_H */