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linux/include/uapi/asm-generic/poll.h

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License cleanup: add SPDX license identifier to uapi header files with no license Many user space API headers are missing licensing information, which makes it hard for compliance tools to determine the correct license. By default are files without license information under the default license of the kernel, which is GPLV2. Marking them GPLV2 would exclude them from being included in non GPLV2 code, which is obviously not intended. The user space API headers fall under the syscall exception which is in the kernels COPYING file: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". otherwise syscall usage would not be possible. Update the files which contain no license information with an SPDX license identifier. The chosen identifier is 'GPL-2.0 WITH Linux-syscall-note' which is the officially assigned identifier for the Linux syscall exception. SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 15:08:43 +01:00
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
Consolidate asm/poll.h These files are almost all the same. This patch could be made even simpler if we don't mind POLLREMOVE turning up in a few architectures that didn't have it previously (which should be OK as POLLREMOVE is not used anywhere in the current tree). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 22:22:40 -07:00
#ifndef __ASM_GENERIC_POLL_H
#define __ASM_GENERIC_POLL_H
/* These are specified by iBCS2 */
unify {de,}mangle_poll(), get rid of kernel-side POLL... except, again, POLLFREE and POLL_BUSY_LOOP. With this, we finally get to the promised end result: - POLL{IN,OUT,...} are plain integers and *not* in __poll_t, so any stray instances of ->poll() still using those will be caught by sparse. - eventpoll.c and select.c warning-free wrt __poll_t - no more kernel-side definitions of POLL... - userland ones are visible through the entire kernel (and used pretty much only for mangle/demangle) - same behavior as after the first series (i.e. sparc et.al. epoll(2) working correctly). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01 15:13:18 -05:00
#define POLLIN 0x0001
#define POLLPRI 0x0002
#define POLLOUT 0x0004
#define POLLERR 0x0008
#define POLLHUP 0x0010
#define POLLNVAL 0x0020
Consolidate asm/poll.h These files are almost all the same. This patch could be made even simpler if we don't mind POLLREMOVE turning up in a few architectures that didn't have it previously (which should be OK as POLLREMOVE is not used anywhere in the current tree). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 22:22:40 -07:00
/* The rest seem to be more-or-less nonstandard. Check them! */
unify {de,}mangle_poll(), get rid of kernel-side POLL... except, again, POLLFREE and POLL_BUSY_LOOP. With this, we finally get to the promised end result: - POLL{IN,OUT,...} are plain integers and *not* in __poll_t, so any stray instances of ->poll() still using those will be caught by sparse. - eventpoll.c and select.c warning-free wrt __poll_t - no more kernel-side definitions of POLL... - userland ones are visible through the entire kernel (and used pretty much only for mangle/demangle) - same behavior as after the first series (i.e. sparc et.al. epoll(2) working correctly). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01 15:13:18 -05:00
#define POLLRDNORM 0x0040
#define POLLRDBAND 0x0080
Consolidate asm/poll.h These files are almost all the same. This patch could be made even simpler if we don't mind POLLREMOVE turning up in a few architectures that didn't have it previously (which should be OK as POLLREMOVE is not used anywhere in the current tree). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 22:22:40 -07:00
#ifndef POLLWRNORM
unify {de,}mangle_poll(), get rid of kernel-side POLL... except, again, POLLFREE and POLL_BUSY_LOOP. With this, we finally get to the promised end result: - POLL{IN,OUT,...} are plain integers and *not* in __poll_t, so any stray instances of ->poll() still using those will be caught by sparse. - eventpoll.c and select.c warning-free wrt __poll_t - no more kernel-side definitions of POLL... - userland ones are visible through the entire kernel (and used pretty much only for mangle/demangle) - same behavior as after the first series (i.e. sparc et.al. epoll(2) working correctly). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01 15:13:18 -05:00
#define POLLWRNORM 0x0100
Consolidate asm/poll.h These files are almost all the same. This patch could be made even simpler if we don't mind POLLREMOVE turning up in a few architectures that didn't have it previously (which should be OK as POLLREMOVE is not used anywhere in the current tree). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 22:22:40 -07:00
#endif
#ifndef POLLWRBAND
unify {de,}mangle_poll(), get rid of kernel-side POLL... except, again, POLLFREE and POLL_BUSY_LOOP. With this, we finally get to the promised end result: - POLL{IN,OUT,...} are plain integers and *not* in __poll_t, so any stray instances of ->poll() still using those will be caught by sparse. - eventpoll.c and select.c warning-free wrt __poll_t - no more kernel-side definitions of POLL... - userland ones are visible through the entire kernel (and used pretty much only for mangle/demangle) - same behavior as after the first series (i.e. sparc et.al. epoll(2) working correctly). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01 15:13:18 -05:00
#define POLLWRBAND 0x0200
Consolidate asm/poll.h These files are almost all the same. This patch could be made even simpler if we don't mind POLLREMOVE turning up in a few architectures that didn't have it previously (which should be OK as POLLREMOVE is not used anywhere in the current tree). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 22:22:40 -07:00
#endif
#ifndef POLLMSG
unify {de,}mangle_poll(), get rid of kernel-side POLL... except, again, POLLFREE and POLL_BUSY_LOOP. With this, we finally get to the promised end result: - POLL{IN,OUT,...} are plain integers and *not* in __poll_t, so any stray instances of ->poll() still using those will be caught by sparse. - eventpoll.c and select.c warning-free wrt __poll_t - no more kernel-side definitions of POLL... - userland ones are visible through the entire kernel (and used pretty much only for mangle/demangle) - same behavior as after the first series (i.e. sparc et.al. epoll(2) working correctly). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01 15:13:18 -05:00
#define POLLMSG 0x0400
Consolidate asm/poll.h These files are almost all the same. This patch could be made even simpler if we don't mind POLLREMOVE turning up in a few architectures that didn't have it previously (which should be OK as POLLREMOVE is not used anywhere in the current tree). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 22:22:40 -07:00
#endif
#ifndef POLLREMOVE
unify {de,}mangle_poll(), get rid of kernel-side POLL... except, again, POLLFREE and POLL_BUSY_LOOP. With this, we finally get to the promised end result: - POLL{IN,OUT,...} are plain integers and *not* in __poll_t, so any stray instances of ->poll() still using those will be caught by sparse. - eventpoll.c and select.c warning-free wrt __poll_t - no more kernel-side definitions of POLL... - userland ones are visible through the entire kernel (and used pretty much only for mangle/demangle) - same behavior as after the first series (i.e. sparc et.al. epoll(2) working correctly). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01 15:13:18 -05:00
#define POLLREMOVE 0x1000
Consolidate asm/poll.h These files are almost all the same. This patch could be made even simpler if we don't mind POLLREMOVE turning up in a few architectures that didn't have it previously (which should be OK as POLLREMOVE is not used anywhere in the current tree). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 22:22:40 -07:00
#endif
#ifndef POLLRDHUP
unify {de,}mangle_poll(), get rid of kernel-side POLL... except, again, POLLFREE and POLL_BUSY_LOOP. With this, we finally get to the promised end result: - POLL{IN,OUT,...} are plain integers and *not* in __poll_t, so any stray instances of ->poll() still using those will be caught by sparse. - eventpoll.c and select.c warning-free wrt __poll_t - no more kernel-side definitions of POLL... - userland ones are visible through the entire kernel (and used pretty much only for mangle/demangle) - same behavior as after the first series (i.e. sparc et.al. epoll(2) working correctly). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01 15:13:18 -05:00
#define POLLRDHUP 0x2000
Consolidate asm/poll.h These files are almost all the same. This patch could be made even simpler if we don't mind POLLREMOVE turning up in a few architectures that didn't have it previously (which should be OK as POLLREMOVE is not used anywhere in the current tree). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 22:22:40 -07:00
#endif
aio: fix use-after-free due to missing POLLFREE handling signalfd_poll() and binder_poll() are special in that they use a waitqueue whose lifetime is the current task, rather than the struct file as is normally the case. This is okay for blocking polls, since a blocking poll occurs within one task; however, non-blocking polls require another solution. This solution is for the queue to be cleared before it is freed, by sending a POLLFREE notification to all waiters. Unfortunately, only eventpoll handles POLLFREE. A second type of non-blocking poll, aio poll, was added in kernel v4.18, and it doesn't handle POLLFREE. This allows a use-after-free to occur if a signalfd or binder fd is polled with aio poll, and the waitqueue gets freed. Fix this by making aio poll handle POLLFREE. A patch by Ramji Jiyani <ramjiyani@google.com> (https://lore.kernel.org/r/20211027011834.2497484-1-ramjiyani@google.com) tried to do this by making aio_poll_wake() always complete the request inline if POLLFREE is seen. However, that solution had two bugs. First, it introduced a deadlock, as it unconditionally locked the aio context while holding the waitqueue lock, which inverts the normal locking order. Second, it didn't consider that POLLFREE notifications are missed while the request has been temporarily de-queued. The second problem was solved by my previous patch. This patch then properly fixes the use-after-free by handling POLLFREE in a deadlock-free way. It does this by taking advantage of the fact that freeing of the waitqueue is RCU-delayed, similar to what eventpoll does. Fixes: 2c14fa838cbe ("aio: implement IOCB_CMD_POLL") Cc: <stable@vger.kernel.org> # v4.18+ Link: https://lore.kernel.org/r/20211209010455.42744-6-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2021-12-08 17:04:55 -08:00
#define POLLFREE (__force __poll_t)0x4000
epoll: introduce POLLFREE to flush ->signalfd_wqh before kfree() This patch is intentionally incomplete to simplify the review. It ignores ep_unregister_pollwait() which plays with the same wqh. See the next change. epoll assumes that the EPOLL_CTL_ADD'ed file controls everything f_op->poll() needs. In particular it assumes that the wait queue can't go away until eventpoll_release(). This is not true in case of signalfd, the task which does EPOLL_CTL_ADD uses its ->sighand which is not connected to the file. This patch adds the special event, POLLFREE, currently only for epoll. It expects that init_poll_funcptr()'ed hook should do the necessary cleanup. Perhaps it should be defined as EPOLLFREE in eventpoll. __cleanup_sighand() is changed to do wake_up_poll(POLLFREE) if ->signalfd_wqh is not empty, we add the new signalfd_cleanup() helper. ep_poll_callback(POLLFREE) simply does list_del_init(task_list). This make this poll entry inconsistent, but we don't care. If you share epoll fd which contains our sigfd with another process you should blame yourself. signalfd is "really special". I simply do not know how we can define the "right" semantics if it used with epoll. The main problem is, epoll calls signalfd_poll() once to establish the connection with the wait queue, after that signalfd_poll(NULL) returns the different/inconsistent results depending on who does EPOLL_CTL_MOD/signalfd_read/etc. IOW: apart from sigmask, signalfd has nothing to do with the file, it works with the current thread. In short: this patch is the hack which tries to fix the symptoms. It also assumes that nobody can take tasklist_lock under epoll locks, this seems to be true. Note: - we do not have wake_up_all_poll() but wake_up_poll() is fine, poll/epoll doesn't use WQ_FLAG_EXCLUSIVE. - signalfd_cleanup() uses POLLHUP along with POLLFREE, we need a couple of simple changes in eventpoll.c to make sure it can't be "lost". Reported-by: Maxime Bizon <mbizon@freebox.fr> Cc: <stable@kernel.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-24 20:07:11 +01:00
define __poll_t, annotate constants Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-02 22:05:03 -04:00
#define POLL_BUSY_LOOP (__force __poll_t)0x8000
net: poll/select low latency socket support select/poll busy-poll support. Split sysctl value into two separate ones, one for read and one for poll. updated Documentation/sysctl/net.txt Add a new poll flag POLL_LL. When this flag is set, sock_poll will call sk_poll_ll if possible. sock_poll sets this flag in its return value to indicate to select/poll when a socket that can busy poll is found. When poll/select have nothing to report, call the low-level sock_poll again until we are out of time or we find something. Once the system call finds something, it stops setting POLL_LL, so it can return the result to the user ASAP. Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-24 10:28:03 +03:00
Consolidate asm/poll.h These files are almost all the same. This patch could be made even simpler if we don't mind POLLREMOVE turning up in a few architectures that didn't have it previously (which should be OK as POLLREMOVE is not used anywhere in the current tree). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 22:22:40 -07:00
struct pollfd {
int fd;
short events;
short revents;
};
#endif /* __ASM_GENERIC_POLL_H */
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