cregit-Linux how code gets into the kernel

Release 4.10 fs/notify/fanotify/fanotify.c

#include <linux/fanotify.h>
#include <linux/fdtable.h>
#include <linux/fsnotify_backend.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/kernel.h> /* UINT_MAX */
#include <linux/mount.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/wait.h>

#include "fanotify.h"

static bool should_merge(struct fsnotify_event *old_fsn, struct fsnotify_event *new_fsn) { struct fanotify_event_info *old, *new; pr_debug("%s: old=%p new=%p\n", __func__, old_fsn, new_fsn); old = FANOTIFY_E(old_fsn); new = FANOTIFY_E(new_fsn); if (old_fsn->inode == new_fsn->inode && old->tgid == new->tgid && old->path.mnt == new->path.mnt && old->path.dentry == new->path.dentry) return true; return false; }


jan karajan kara4950.52%125.00%
eric pariseric paris4243.30%125.00%
linus torvaldslinus torvalds44.12%125.00%
andreas gruenbacherandreas gruenbacher22.06%125.00%

/* and the list better be locked by something too! */
static int fanotify_merge(struct list_head *list, struct fsnotify_event *event) { struct fsnotify_event *test_event; bool do_merge = false; pr_debug("%s: list=%p event=%p\n", __func__, list, event); #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS /* * Don't merge a permission event with any other event so that we know * the event structure we have created in fanotify_handle_event() is the * one we should check for permission response. */ if (event->mask & FAN_ALL_PERM_EVENTS) return 0; #endif list_for_each_entry_reverse(test_event, list, list) { if (should_merge(test_event, event)) { do_merge = true; break; } } if (!do_merge) return 0; test_event->mask |= event->mask; return 1; }


eric pariseric paris6969.70%457.14%
jan karajan kara3030.30%342.86%

static int fanotify_get_response(struct fsnotify_group *group, struct fanotify_perm_event_info *event) { int ret; pr_debug("%s: group=%p event=%p\n", __func__, group, event); wait_event(group->fanotify_data.access_waitq, event->response); /* userspace responded, convert to something usable */ switch (event->response) { case FAN_ALLOW: ret = 0; break; case FAN_DENY: default: ret = -EPERM; } event->response = 0; pr_debug("%s: group=%p event=%p about to return ret=%d\n", __func__, group, event, ret); return ret; }


eric pariseric paris8795.60%250.00%
jan karajan kara44.40%250.00%

static bool fanotify_should_send_event(struct fsnotify_mark *inode_mark, struct fsnotify_mark *vfsmnt_mark, u32 event_mask, const void *data, int data_type) { __u32 marks_mask, marks_ignored_mask; const struct path *path = data; pr_debug("%s: inode_mark=%p vfsmnt_mark=%p mask=%x data=%p" " data_type=%d\n", __func__, inode_mark, vfsmnt_mark, event_mask, data, data_type); /* if we don't have enough info to send an event to userspace say no */ if (data_type != FSNOTIFY_EVENT_PATH) return false; /* sorry, fanotify only gives a damn about files and dirs */ if (!d_is_reg(path->dentry) && !d_can_lookup(path->dentry)) return false; if (inode_mark && vfsmnt_mark) { marks_mask = (vfsmnt_mark->mask | inode_mark->mask); marks_ignored_mask = (vfsmnt_mark->ignored_mask | inode_mark->ignored_mask); } else if (inode_mark) { /* * if the event is for a child and this inode doesn't care about * events on the child, don't send it! */ if ((event_mask & FS_EVENT_ON_CHILD) && !(inode_mark->mask & FS_EVENT_ON_CHILD)) return false; marks_mask = inode_mark->mask; marks_ignored_mask = inode_mark->ignored_mask; } else if (vfsmnt_mark) { marks_mask = vfsmnt_mark->mask; marks_ignored_mask = vfsmnt_mark->ignored_mask; } else { BUG(); } if (d_is_dir(path->dentry) && !(marks_mask & FS_ISDIR & ~marks_ignored_mask)) return false; if (event_mask & FAN_ALL_OUTGOING_EVENTS & marks_mask & ~marks_ignored_mask) return true; return false; }


eric pariseric paris19385.40%956.25%
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lino sanfilippolino sanfilippo52.21%16.25%
david howellsdavid howells31.33%212.50%
suzuki k poulosesuzuki k poulose20.88%16.25%
al viroal viro20.88%16.25%

struct fanotify_event_info *fanotify_alloc_event(struct inode *inode, u32 mask, const struct path *path) { struct fanotify_event_info *event; #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS if (mask & FAN_ALL_PERM_EVENTS) { struct fanotify_perm_event_info *pevent; pevent = kmem_cache_alloc(fanotify_perm_event_cachep, GFP_KERNEL); if (!pevent) return NULL; event = &pevent->fae; pevent->response = 0; goto init; } #endif event = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL); if (!event) return NULL; init: __maybe_unused fsnotify_init_event(&event->fse, inode, mask); event->tgid = get_pid(task_tgid(current)); if (path) { event->path = *path; path_get(&event->path); } else { event->path.mnt = NULL; event->path.dentry = NULL; } return event; }


jan karajan kara16399.39%150.00%
al viroal viro10.61%150.00%

static int fanotify_handle_event(struct fsnotify_group *group, struct inode *inode, struct fsnotify_mark *inode_mark, struct fsnotify_mark *fanotify_mark, u32 mask, const void *data, int data_type, const unsigned char *file_name, u32 cookie) { int ret = 0; struct fanotify_event_info *event; struct fsnotify_event *fsn_event; BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS); BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY); BUILD_BUG_ON(FAN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE); BUILD_BUG_ON(FAN_CLOSE_WRITE != FS_CLOSE_WRITE); BUILD_BUG_ON(FAN_OPEN != FS_OPEN); BUILD_BUG_ON(FAN_EVENT_ON_CHILD != FS_EVENT_ON_CHILD); BUILD_BUG_ON(FAN_Q_OVERFLOW != FS_Q_OVERFLOW); BUILD_BUG_ON(FAN_OPEN_PERM != FS_OPEN_PERM); BUILD_BUG_ON(FAN_ACCESS_PERM != FS_ACCESS_PERM); BUILD_BUG_ON(FAN_ONDIR != FS_ISDIR); if (!fanotify_should_send_event(inode_mark, fanotify_mark, mask, data, data_type)) return 0; pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, group, inode, mask); event = fanotify_alloc_event(inode, mask, data); if (unlikely(!event)) return -ENOMEM; fsn_event = &event->fse; ret = fsnotify_add_event(group, fsn_event, fanotify_merge); if (ret) { /* Permission events shouldn't be merged */ BUG_ON(ret == 1 && mask & FAN_ALL_PERM_EVENTS); /* Our event wasn't used in the end. Free it. */ fsnotify_destroy_event(group, fsn_event); return 0; } #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS if (mask & FAN_ALL_PERM_EVENTS) { ret = fanotify_get_response(group, FANOTIFY_PE(fsn_event)); fsnotify_destroy_event(group, fsn_event); } #endif return ret; }


jan karajan kara25595.15%880.00%
eric pariseric paris124.48%110.00%
al viroal viro10.37%110.00%

static void fanotify_free_group_priv(struct fsnotify_group *group) { struct user_struct *user; user = group->fanotify_data.user; atomic_dec(&user->fanotify_listeners); free_uid(user); }


jan karajan kara2978.38%150.00%
eric pariseric paris821.62%150.00%

static void fanotify_free_event(struct fsnotify_event *fsn_event) { struct fanotify_event_info *event; event = FANOTIFY_E(fsn_event); path_put(&event->path); put_pid(event->tgid); #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS if (fsn_event->mask & FAN_ALL_PERM_EVENTS) { kmem_cache_free(fanotify_perm_event_cachep, FANOTIFY_PE(fsn_event)); return; } #endif kmem_cache_free(fanotify_event_cachep, event); }


jan karajan kara71100.00%2100.00%

const struct fsnotify_ops fanotify_fsnotify_ops = { .handle_event = fanotify_handle_event, .free_group_priv = fanotify_free_group_priv, .free_event = fanotify_free_event, };

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al viroal viro40.36%13.03%
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