From aa6f5ffbdba45aa8e19e5048648fc6c7b25376d3 Mon Sep 17 00:00:00 2001 From: merge Date: Thu, 22 Jan 2009 13:55:32 +0000 Subject: MERGE-via-pending-tracking-hist-MERGE-via-stable-tracking-MERGE-via-mokopatches-tracking-fix-stray-endmenu-patch-1232632040-1232632141 pending-tracking-hist top was MERGE-via-stable-tracking-MERGE-via-mokopatches-tracking-fix-stray-endmenu-patch-1232632040-1232632141 / fdf777a63bcb59e0dfd78bfe2c6242e01f6d4eb9 ... parent commitmessage: From: merge MERGE-via-stable-tracking-hist-MERGE-via-mokopatches-tracking-fix-stray-endmenu-patch-1232632040 stable-tracking-hist top was MERGE-via-mokopatches-tracking-fix-stray-endmenu-patch-1232632040 / 90463bfd2d5a3c8b52f6e6d71024a00e052b0ced ... parent commitmessage: From: merge MERGE-via-mokopatches-tracking-hist-fix-stray-endmenu-patch mokopatches-tracking-hist top was fix-stray-endmenu-patch / 3630e0be570de8057e7f8d2fe501ed353cdf34e6 ... parent commitmessage: From: Andy Green fix-stray-endmenu.patch Signed-off-by: Andy Green --- fs/eventpoll.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 86 insertions(+), 17 deletions(-) (limited to 'fs/eventpoll.c') diff --git a/fs/eventpoll.c b/fs/eventpoll.c index aec5c13f634..ba2f9ec7119 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -102,6 +102,8 @@ #define EP_UNACTIVE_PTR ((void *) -1L) +#define EP_ITEM_COST (sizeof(struct epitem) + sizeof(struct eppoll_entry)) + struct epoll_filefd { struct file *file; int fd; @@ -200,6 +202,9 @@ struct eventpoll { * holding ->lock. */ struct epitem *ovflist; + + /* The user that created the eventpoll descriptor */ + struct user_struct *user; }; /* Wait structure used by the poll hooks */ @@ -226,10 +231,18 @@ struct ep_pqueue { struct epitem *epi; }; +/* + * Configuration options available inside /proc/sys/fs/epoll/ + */ +/* Maximum number of epoll devices, per user */ +static int max_user_instances __read_mostly; +/* Maximum number of epoll watched descriptors, per user */ +static int max_user_watches __read_mostly; + /* * This mutex is used to serialize ep_free() and eventpoll_release_file(). */ -static struct mutex epmutex; +static DEFINE_MUTEX(epmutex); /* Safe wake up implementation */ static struct poll_safewake psw; @@ -240,6 +253,33 @@ static struct kmem_cache *epi_cache __read_mostly; /* Slab cache used to allocate "struct eppoll_entry" */ static struct kmem_cache *pwq_cache __read_mostly; +#ifdef CONFIG_SYSCTL + +#include + +static int zero; + +ctl_table epoll_table[] = { + { + .procname = "max_user_instances", + .data = &max_user_instances, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .extra1 = &zero, + }, + { + .procname = "max_user_watches", + .data = &max_user_watches, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .extra1 = &zero, + }, + { .ctl_name = 0 } +}; +#endif /* CONFIG_SYSCTL */ + /* Setup the structure that is used as key for the RB tree */ static inline void ep_set_ffd(struct epoll_filefd *ffd, @@ -402,6 +442,8 @@ static int ep_remove(struct eventpoll *ep, struct epitem *epi) /* At this point it is safe to free the eventpoll item */ kmem_cache_free(epi_cache, epi); + atomic_dec(&ep->user->epoll_watches); + DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_remove(%p, %p)\n", current, ep, file)); @@ -449,6 +491,8 @@ static void ep_free(struct eventpoll *ep) mutex_unlock(&epmutex); mutex_destroy(&ep->mtx); + atomic_dec(&ep->user->epoll_devs); + free_uid(ep->user); kfree(ep); } @@ -532,10 +576,19 @@ void eventpoll_release_file(struct file *file) static int ep_alloc(struct eventpoll **pep) { - struct eventpoll *ep = kzalloc(sizeof(*ep), GFP_KERNEL); + int error; + struct user_struct *user; + struct eventpoll *ep; - if (!ep) - return -ENOMEM; + user = get_current_user(); + error = -EMFILE; + if (unlikely(atomic_read(&user->epoll_devs) >= + max_user_instances)) + goto free_uid; + error = -ENOMEM; + ep = kzalloc(sizeof(*ep), GFP_KERNEL); + if (unlikely(!ep)) + goto free_uid; spin_lock_init(&ep->lock); mutex_init(&ep->mtx); @@ -544,12 +597,17 @@ static int ep_alloc(struct eventpoll **pep) INIT_LIST_HEAD(&ep->rdllist); ep->rbr = RB_ROOT; ep->ovflist = EP_UNACTIVE_PTR; + ep->user = user; *pep = ep; DNPRINTK(3, (KERN_INFO "[%p] eventpoll: ep_alloc() ep=%p\n", current, ep)); return 0; + +free_uid: + free_uid(user); + return error; } /* @@ -703,9 +761,11 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event, struct epitem *epi; struct ep_pqueue epq; - error = -ENOMEM; + if (unlikely(atomic_read(&ep->user->epoll_watches) >= + max_user_watches)) + return -ENOSPC; if (!(epi = kmem_cache_alloc(epi_cache, GFP_KERNEL))) - goto error_return; + return -ENOMEM; /* Item initialization follow here ... */ INIT_LIST_HEAD(&epi->rdllink); @@ -735,6 +795,7 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event, * install process. Namely an allocation for a wait queue failed due * high memory pressure. */ + error = -ENOMEM; if (epi->nwait < 0) goto error_unregister; @@ -765,6 +826,8 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event, spin_unlock_irqrestore(&ep->lock, flags); + atomic_inc(&ep->user->epoll_watches); + /* We have to call this outside the lock */ if (pwake) ep_poll_safewake(&psw, &ep->poll_wait); @@ -789,7 +852,7 @@ error_unregister: spin_unlock_irqrestore(&ep->lock, flags); kmem_cache_free(epi_cache, epi); -error_return: + return error; } @@ -1047,7 +1110,7 @@ retry: /* * Open an eventpoll file descriptor. */ -asmlinkage long sys_epoll_create1(int flags) +SYSCALL_DEFINE1(epoll_create1, int, flags) { int error, fd = -1; struct eventpoll *ep; @@ -1078,6 +1141,7 @@ asmlinkage long sys_epoll_create1(int flags) flags & O_CLOEXEC); if (fd < 0) ep_free(ep); + atomic_inc(&ep->user->epoll_devs); error_return: DNPRINTK(3, (KERN_INFO "[%p] eventpoll: sys_epoll_create(%d) = %d\n", @@ -1086,7 +1150,7 @@ error_return: return fd; } -asmlinkage long sys_epoll_create(int size) +SYSCALL_DEFINE1(epoll_create, int, size) { if (size < 0) return -EINVAL; @@ -1099,8 +1163,8 @@ asmlinkage long sys_epoll_create(int size) * the eventpoll file that enables the insertion/removal/change of * file descriptors inside the interest set. */ -asmlinkage long sys_epoll_ctl(int epfd, int op, int fd, - struct epoll_event __user *event) +SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd, + struct epoll_event __user *, event) { int error; struct file *file, *tfile; @@ -1197,8 +1261,8 @@ error_return: * Implement the event wait interface for the eventpoll file. It is the kernel * part of the user space epoll_wait(2). */ -asmlinkage long sys_epoll_wait(int epfd, struct epoll_event __user *events, - int maxevents, int timeout) +SYSCALL_DEFINE4(epoll_wait, int, epfd, struct epoll_event __user *, events, + int, maxevents, int, timeout) { int error; struct file *file; @@ -1255,9 +1319,9 @@ error_return: * Implement the event wait interface for the eventpoll file. It is the kernel * part of the user space epoll_pwait(2). */ -asmlinkage long sys_epoll_pwait(int epfd, struct epoll_event __user *events, - int maxevents, int timeout, const sigset_t __user *sigmask, - size_t sigsetsize) +SYSCALL_DEFINE6(epoll_pwait, int, epfd, struct epoll_event __user *, events, + int, maxevents, int, timeout, const sigset_t __user *, sigmask, + size_t, sigsetsize) { int error; sigset_t ksigmask, sigsaved; @@ -1299,7 +1363,12 @@ asmlinkage long sys_epoll_pwait(int epfd, struct epoll_event __user *events, static int __init eventpoll_init(void) { - mutex_init(&epmutex); + struct sysinfo si; + + si_meminfo(&si); + max_user_instances = 128; + max_user_watches = (((si.totalram - si.totalhigh) / 32) << PAGE_SHIFT) / + EP_ITEM_COST; /* Initialize the structure used to perform safe poll wait head wake ups */ ep_poll_safewake_init(&psw); -- cgit v1.2.3