Revision 8f4d38099b3098eae75f7755e1801931f8141350 authored by Ville Syrjälä on 15 December 2016, 17:47:34 UTC, committed by Jani Nikula on 07 June 2017, 13:31:39 UTC
The scanline counter is bonkers on VLV/CHV DSI. The scanline counter increment is not lined up with the start of vblank like it is on every other platform and output type. This causes problems for both the vblank timestamping and atomic update vblank evasion. On my FFRD8 machine at least, the scanline counter increment happens about 1/3 of a scanline ahead of the start of vblank (which is where all register latching happens still). That means we can't trust the scanline counter to tell us whether we're in vblank or not while we're on that particular line. In order to keep vblank timestamping in working condition when called from the vblank irq, we'll leave scanline_offset at one, which means that the entire line containing the start of vblank is considered to be inside the vblank. For the vblank evasion we'll need to consider that entire line to be bad, since we can't tell whether the registers already got latched or not. And we can't actually use the start of vblank interrupt to get us past that line as the interrupt would fire too soon, and then we'd up waiting for the next start of vblank instead. One way around that would using the frame start interrupt instead since that wouldn't fire until the next scanline, but that would require some bigger changes in the interrupt code. So for simplicity we'll just poll until we get past the bad line. v2: Adjust the comments a bit Cc: stable@vger.kernel.org Cc: Jonas Aaberg <cja@gmx.net> Tested-by: Jonas Aaberg <cja@gmx.net> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99086 Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161215174734.28779-1-ville.syrjala@linux.intel.com Tested-by: Mika Kahola <mika.kahola@intel.com> Reviewed-by: Mika Kahola <mika.kahola@intel.com> (cherry picked from commit ec1b4ee2834e66884e5b0d3d465f347ff212e372) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
1 parent 5857dbf
fcntl.c
/*
* linux/fs/fcntl.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include <linux/syscalls.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/sched/task.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/capability.h>
#include <linux/dnotify.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/pipe_fs_i.h>
#include <linux/security.h>
#include <linux/ptrace.h>
#include <linux/signal.h>
#include <linux/rcupdate.h>
#include <linux/pid_namespace.h>
#include <linux/user_namespace.h>
#include <linux/shmem_fs.h>
#include <linux/compat.h>
#include <asm/poll.h>
#include <asm/siginfo.h>
#include <linux/uaccess.h>
#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME)
static int setfl(int fd, struct file * filp, unsigned long arg)
{
struct inode * inode = file_inode(filp);
int error = 0;
/*
* O_APPEND cannot be cleared if the file is marked as append-only
* and the file is open for write.
*/
if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode))
return -EPERM;
/* O_NOATIME can only be set by the owner or superuser */
if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME))
if (!inode_owner_or_capable(inode))
return -EPERM;
/* required for strict SunOS emulation */
if (O_NONBLOCK != O_NDELAY)
if (arg & O_NDELAY)
arg |= O_NONBLOCK;
/* Pipe packetized mode is controlled by O_DIRECT flag */
if (!S_ISFIFO(inode->i_mode) && (arg & O_DIRECT)) {
if (!filp->f_mapping || !filp->f_mapping->a_ops ||
!filp->f_mapping->a_ops->direct_IO)
return -EINVAL;
}
if (filp->f_op->check_flags)
error = filp->f_op->check_flags(arg);
if (error)
return error;
/*
* ->fasync() is responsible for setting the FASYNC bit.
*/
if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op->fasync) {
error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
if (error < 0)
goto out;
if (error > 0)
error = 0;
}
spin_lock(&filp->f_lock);
filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
spin_unlock(&filp->f_lock);
out:
return error;
}
static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
int force)
{
write_lock_irq(&filp->f_owner.lock);
if (force || !filp->f_owner.pid) {
put_pid(filp->f_owner.pid);
filp->f_owner.pid = get_pid(pid);
filp->f_owner.pid_type = type;
if (pid) {
const struct cred *cred = current_cred();
filp->f_owner.uid = cred->uid;
filp->f_owner.euid = cred->euid;
}
}
write_unlock_irq(&filp->f_owner.lock);
}
void __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
int force)
{
security_file_set_fowner(filp);
f_modown(filp, pid, type, force);
}
EXPORT_SYMBOL(__f_setown);
void f_setown(struct file *filp, unsigned long arg, int force)
{
enum pid_type type;
struct pid *pid;
int who = arg;
type = PIDTYPE_PID;
if (who < 0) {
type = PIDTYPE_PGID;
who = -who;
}
rcu_read_lock();
pid = find_vpid(who);
__f_setown(filp, pid, type, force);
rcu_read_unlock();
}
EXPORT_SYMBOL(f_setown);
void f_delown(struct file *filp)
{
f_modown(filp, NULL, PIDTYPE_PID, 1);
}
pid_t f_getown(struct file *filp)
{
pid_t pid;
read_lock(&filp->f_owner.lock);
pid = pid_vnr(filp->f_owner.pid);
if (filp->f_owner.pid_type == PIDTYPE_PGID)
pid = -pid;
read_unlock(&filp->f_owner.lock);
return pid;
}
static int f_setown_ex(struct file *filp, unsigned long arg)
{
struct f_owner_ex __user *owner_p = (void __user *)arg;
struct f_owner_ex owner;
struct pid *pid;
int type;
int ret;
ret = copy_from_user(&owner, owner_p, sizeof(owner));
if (ret)
return -EFAULT;
switch (owner.type) {
case F_OWNER_TID:
type = PIDTYPE_MAX;
break;
case F_OWNER_PID:
type = PIDTYPE_PID;
break;
case F_OWNER_PGRP:
type = PIDTYPE_PGID;
break;
default:
return -EINVAL;
}
rcu_read_lock();
pid = find_vpid(owner.pid);
if (owner.pid && !pid)
ret = -ESRCH;
else
__f_setown(filp, pid, type, 1);
rcu_read_unlock();
return ret;
}
static int f_getown_ex(struct file *filp, unsigned long arg)
{
struct f_owner_ex __user *owner_p = (void __user *)arg;
struct f_owner_ex owner;
int ret = 0;
read_lock(&filp->f_owner.lock);
owner.pid = pid_vnr(filp->f_owner.pid);
switch (filp->f_owner.pid_type) {
case PIDTYPE_MAX:
owner.type = F_OWNER_TID;
break;
case PIDTYPE_PID:
owner.type = F_OWNER_PID;
break;
case PIDTYPE_PGID:
owner.type = F_OWNER_PGRP;
break;
default:
WARN_ON(1);
ret = -EINVAL;
break;
}
read_unlock(&filp->f_owner.lock);
if (!ret) {
ret = copy_to_user(owner_p, &owner, sizeof(owner));
if (ret)
ret = -EFAULT;
}
return ret;
}
#ifdef CONFIG_CHECKPOINT_RESTORE
static int f_getowner_uids(struct file *filp, unsigned long arg)
{
struct user_namespace *user_ns = current_user_ns();
uid_t __user *dst = (void __user *)arg;
uid_t src[2];
int err;
read_lock(&filp->f_owner.lock);
src[0] = from_kuid(user_ns, filp->f_owner.uid);
src[1] = from_kuid(user_ns, filp->f_owner.euid);
read_unlock(&filp->f_owner.lock);
err = put_user(src[0], &dst[0]);
err |= put_user(src[1], &dst[1]);
return err;
}
#else
static int f_getowner_uids(struct file *filp, unsigned long arg)
{
return -EINVAL;
}
#endif
static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
struct file *filp)
{
long err = -EINVAL;
switch (cmd) {
case F_DUPFD:
err = f_dupfd(arg, filp, 0);
break;
case F_DUPFD_CLOEXEC:
err = f_dupfd(arg, filp, O_CLOEXEC);
break;
case F_GETFD:
err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;
break;
case F_SETFD:
err = 0;
set_close_on_exec(fd, arg & FD_CLOEXEC);
break;
case F_GETFL:
err = filp->f_flags;
break;
case F_SETFL:
err = setfl(fd, filp, arg);
break;
#if BITS_PER_LONG != 32
/* 32-bit arches must use fcntl64() */
case F_OFD_GETLK:
#endif
case F_GETLK:
err = fcntl_getlk(filp, cmd, (struct flock __user *) arg);
break;
#if BITS_PER_LONG != 32
/* 32-bit arches must use fcntl64() */
case F_OFD_SETLK:
case F_OFD_SETLKW:
#endif
/* Fallthrough */
case F_SETLK:
case F_SETLKW:
err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg);
break;
case F_GETOWN:
/*
* XXX If f_owner is a process group, the
* negative return value will get converted
* into an error. Oops. If we keep the
* current syscall conventions, the only way
* to fix this will be in libc.
*/
err = f_getown(filp);
force_successful_syscall_return();
break;
case F_SETOWN:
f_setown(filp, arg, 1);
err = 0;
break;
case F_GETOWN_EX:
err = f_getown_ex(filp, arg);
break;
case F_SETOWN_EX:
err = f_setown_ex(filp, arg);
break;
case F_GETOWNER_UIDS:
err = f_getowner_uids(filp, arg);
break;
case F_GETSIG:
err = filp->f_owner.signum;
break;
case F_SETSIG:
/* arg == 0 restores default behaviour. */
if (!valid_signal(arg)) {
break;
}
err = 0;
filp->f_owner.signum = arg;
break;
case F_GETLEASE:
err = fcntl_getlease(filp);
break;
case F_SETLEASE:
err = fcntl_setlease(fd, filp, arg);
break;
case F_NOTIFY:
err = fcntl_dirnotify(fd, filp, arg);
break;
case F_SETPIPE_SZ:
case F_GETPIPE_SZ:
err = pipe_fcntl(filp, cmd, arg);
break;
case F_ADD_SEALS:
case F_GET_SEALS:
err = shmem_fcntl(filp, cmd, arg);
break;
default:
break;
}
return err;
}
static int check_fcntl_cmd(unsigned cmd)
{
switch (cmd) {
case F_DUPFD:
case F_DUPFD_CLOEXEC:
case F_GETFD:
case F_SETFD:
case F_GETFL:
return 1;
}
return 0;
}
SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
{
struct fd f = fdget_raw(fd);
long err = -EBADF;
if (!f.file)
goto out;
if (unlikely(f.file->f_mode & FMODE_PATH)) {
if (!check_fcntl_cmd(cmd))
goto out1;
}
err = security_file_fcntl(f.file, cmd, arg);
if (!err)
err = do_fcntl(fd, cmd, arg, f.file);
out1:
fdput(f);
out:
return err;
}
#if BITS_PER_LONG == 32
SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
unsigned long, arg)
{
struct fd f = fdget_raw(fd);
long err = -EBADF;
if (!f.file)
goto out;
if (unlikely(f.file->f_mode & FMODE_PATH)) {
if (!check_fcntl_cmd(cmd))
goto out1;
}
err = security_file_fcntl(f.file, cmd, arg);
if (err)
goto out1;
switch (cmd) {
case F_GETLK64:
case F_OFD_GETLK:
err = fcntl_getlk64(f.file, cmd, (struct flock64 __user *) arg);
break;
case F_SETLK64:
case F_SETLKW64:
case F_OFD_SETLK:
case F_OFD_SETLKW:
err = fcntl_setlk64(fd, f.file, cmd,
(struct flock64 __user *) arg);
break;
default:
err = do_fcntl(fd, cmd, arg, f.file);
break;
}
out1:
fdput(f);
out:
return err;
}
#endif
#ifdef CONFIG_COMPAT
static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
{
if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
__get_user(kfl->l_type, &ufl->l_type) ||
__get_user(kfl->l_whence, &ufl->l_whence) ||
__get_user(kfl->l_start, &ufl->l_start) ||
__get_user(kfl->l_len, &ufl->l_len) ||
__get_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}
static int put_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
{
if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
__put_user(kfl->l_type, &ufl->l_type) ||
__put_user(kfl->l_whence, &ufl->l_whence) ||
__put_user(kfl->l_start, &ufl->l_start) ||
__put_user(kfl->l_len, &ufl->l_len) ||
__put_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}
#ifndef HAVE_ARCH_GET_COMPAT_FLOCK64
static int get_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
{
if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
__get_user(kfl->l_type, &ufl->l_type) ||
__get_user(kfl->l_whence, &ufl->l_whence) ||
__get_user(kfl->l_start, &ufl->l_start) ||
__get_user(kfl->l_len, &ufl->l_len) ||
__get_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}
#endif
#ifndef HAVE_ARCH_PUT_COMPAT_FLOCK64
static int put_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
{
if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
__put_user(kfl->l_type, &ufl->l_type) ||
__put_user(kfl->l_whence, &ufl->l_whence) ||
__put_user(kfl->l_start, &ufl->l_start) ||
__put_user(kfl->l_len, &ufl->l_len) ||
__put_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}
#endif
static unsigned int
convert_fcntl_cmd(unsigned int cmd)
{
switch (cmd) {
case F_GETLK64:
return F_GETLK;
case F_SETLK64:
return F_SETLK;
case F_SETLKW64:
return F_SETLKW;
}
return cmd;
}
COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
compat_ulong_t, arg)
{
mm_segment_t old_fs;
struct flock f;
long ret;
unsigned int conv_cmd;
switch (cmd) {
case F_GETLK:
case F_SETLK:
case F_SETLKW:
ret = get_compat_flock(&f, compat_ptr(arg));
if (ret != 0)
break;
old_fs = get_fs();
set_fs(KERNEL_DS);
ret = sys_fcntl(fd, cmd, (unsigned long)&f);
set_fs(old_fs);
if (cmd == F_GETLK && ret == 0) {
/* GETLK was successful and we need to return the data...
* but it needs to fit in the compat structure.
* l_start shouldn't be too big, unless the original
* start + end is greater than COMPAT_OFF_T_MAX, in which
* case the app was asking for trouble, so we return
* -EOVERFLOW in that case.
* l_len could be too big, in which case we just truncate it,
* and only allow the app to see that part of the conflicting
* lock that might make sense to it anyway
*/
if (f.l_start > COMPAT_OFF_T_MAX)
ret = -EOVERFLOW;
if (f.l_len > COMPAT_OFF_T_MAX)
f.l_len = COMPAT_OFF_T_MAX;
if (ret == 0)
ret = put_compat_flock(&f, compat_ptr(arg));
}
break;
case F_GETLK64:
case F_SETLK64:
case F_SETLKW64:
case F_OFD_GETLK:
case F_OFD_SETLK:
case F_OFD_SETLKW:
ret = get_compat_flock64(&f, compat_ptr(arg));
if (ret != 0)
break;
old_fs = get_fs();
set_fs(KERNEL_DS);
conv_cmd = convert_fcntl_cmd(cmd);
ret = sys_fcntl(fd, conv_cmd, (unsigned long)&f);
set_fs(old_fs);
if ((conv_cmd == F_GETLK || conv_cmd == F_OFD_GETLK) && ret == 0) {
/* need to return lock information - see above for commentary */
if (f.l_start > COMPAT_LOFF_T_MAX)
ret = -EOVERFLOW;
if (f.l_len > COMPAT_LOFF_T_MAX)
f.l_len = COMPAT_LOFF_T_MAX;
if (ret == 0)
ret = put_compat_flock64(&f, compat_ptr(arg));
}
break;
default:
ret = sys_fcntl(fd, cmd, arg);
break;
}
return ret;
}
COMPAT_SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd,
compat_ulong_t, arg)
{
switch (cmd) {
case F_GETLK64:
case F_SETLK64:
case F_SETLKW64:
case F_OFD_GETLK:
case F_OFD_SETLK:
case F_OFD_SETLKW:
return -EINVAL;
}
return compat_sys_fcntl64(fd, cmd, arg);
}
#endif
/* Table to convert sigio signal codes into poll band bitmaps */
static const long band_table[NSIGPOLL] = {
POLLIN | POLLRDNORM, /* POLL_IN */
POLLOUT | POLLWRNORM | POLLWRBAND, /* POLL_OUT */
POLLIN | POLLRDNORM | POLLMSG, /* POLL_MSG */
POLLERR, /* POLL_ERR */
POLLPRI | POLLRDBAND, /* POLL_PRI */
POLLHUP | POLLERR /* POLL_HUP */
};
static inline int sigio_perm(struct task_struct *p,
struct fown_struct *fown, int sig)
{
const struct cred *cred;
int ret;
rcu_read_lock();
cred = __task_cred(p);
ret = ((uid_eq(fown->euid, GLOBAL_ROOT_UID) ||
uid_eq(fown->euid, cred->suid) || uid_eq(fown->euid, cred->uid) ||
uid_eq(fown->uid, cred->suid) || uid_eq(fown->uid, cred->uid)) &&
!security_file_send_sigiotask(p, fown, sig));
rcu_read_unlock();
return ret;
}
static void send_sigio_to_task(struct task_struct *p,
struct fown_struct *fown,
int fd, int reason, int group)
{
/*
* F_SETSIG can change ->signum lockless in parallel, make
* sure we read it once and use the same value throughout.
*/
int signum = ACCESS_ONCE(fown->signum);
if (!sigio_perm(p, fown, signum))
return;
switch (signum) {
siginfo_t si;
default:
/* Queue a rt signal with the appropriate fd as its
value. We use SI_SIGIO as the source, not
SI_KERNEL, since kernel signals always get
delivered even if we can't queue. Failure to
queue in this case _should_ be reported; we fall
back to SIGIO in that case. --sct */
si.si_signo = signum;
si.si_errno = 0;
si.si_code = reason;
/* Make sure we are called with one of the POLL_*
reasons, otherwise we could leak kernel stack into
userspace. */
BUG_ON((reason & __SI_MASK) != __SI_POLL);
if (reason - POLL_IN >= NSIGPOLL)
si.si_band = ~0L;
else
si.si_band = band_table[reason - POLL_IN];
si.si_fd = fd;
if (!do_send_sig_info(signum, &si, p, group))
break;
/* fall-through: fall back on the old plain SIGIO signal */
case 0:
do_send_sig_info(SIGIO, SEND_SIG_PRIV, p, group);
}
}
void send_sigio(struct fown_struct *fown, int fd, int band)
{
struct task_struct *p;
enum pid_type type;
struct pid *pid;
int group = 1;
read_lock(&fown->lock);
type = fown->pid_type;
if (type == PIDTYPE_MAX) {
group = 0;
type = PIDTYPE_PID;
}
pid = fown->pid;
if (!pid)
goto out_unlock_fown;
read_lock(&tasklist_lock);
do_each_pid_task(pid, type, p) {
send_sigio_to_task(p, fown, fd, band, group);
} while_each_pid_task(pid, type, p);
read_unlock(&tasklist_lock);
out_unlock_fown:
read_unlock(&fown->lock);
}
static void send_sigurg_to_task(struct task_struct *p,
struct fown_struct *fown, int group)
{
if (sigio_perm(p, fown, SIGURG))
do_send_sig_info(SIGURG, SEND_SIG_PRIV, p, group);
}
int send_sigurg(struct fown_struct *fown)
{
struct task_struct *p;
enum pid_type type;
struct pid *pid;
int group = 1;
int ret = 0;
read_lock(&fown->lock);
type = fown->pid_type;
if (type == PIDTYPE_MAX) {
group = 0;
type = PIDTYPE_PID;
}
pid = fown->pid;
if (!pid)
goto out_unlock_fown;
ret = 1;
read_lock(&tasklist_lock);
do_each_pid_task(pid, type, p) {
send_sigurg_to_task(p, fown, group);
} while_each_pid_task(pid, type, p);
read_unlock(&tasklist_lock);
out_unlock_fown:
read_unlock(&fown->lock);
return ret;
}
static DEFINE_SPINLOCK(fasync_lock);
static struct kmem_cache *fasync_cache __read_mostly;
static void fasync_free_rcu(struct rcu_head *head)
{
kmem_cache_free(fasync_cache,
container_of(head, struct fasync_struct, fa_rcu));
}
/*
* Remove a fasync entry. If successfully removed, return
* positive and clear the FASYNC flag. If no entry exists,
* do nothing and return 0.
*
* NOTE! It is very important that the FASYNC flag always
* match the state "is the filp on a fasync list".
*
*/
int fasync_remove_entry(struct file *filp, struct fasync_struct **fapp)
{
struct fasync_struct *fa, **fp;
int result = 0;
spin_lock(&filp->f_lock);
spin_lock(&fasync_lock);
for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
if (fa->fa_file != filp)
continue;
spin_lock_irq(&fa->fa_lock);
fa->fa_file = NULL;
spin_unlock_irq(&fa->fa_lock);
*fp = fa->fa_next;
call_rcu(&fa->fa_rcu, fasync_free_rcu);
filp->f_flags &= ~FASYNC;
result = 1;
break;
}
spin_unlock(&fasync_lock);
spin_unlock(&filp->f_lock);
return result;
}
struct fasync_struct *fasync_alloc(void)
{
return kmem_cache_alloc(fasync_cache, GFP_KERNEL);
}
/*
* NOTE! This can be used only for unused fasync entries:
* entries that actually got inserted on the fasync list
* need to be released by rcu - see fasync_remove_entry.
*/
void fasync_free(struct fasync_struct *new)
{
kmem_cache_free(fasync_cache, new);
}
/*
* Insert a new entry into the fasync list. Return the pointer to the
* old one if we didn't use the new one.
*
* NOTE! It is very important that the FASYNC flag always
* match the state "is the filp on a fasync list".
*/
struct fasync_struct *fasync_insert_entry(int fd, struct file *filp, struct fasync_struct **fapp, struct fasync_struct *new)
{
struct fasync_struct *fa, **fp;
spin_lock(&filp->f_lock);
spin_lock(&fasync_lock);
for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
if (fa->fa_file != filp)
continue;
spin_lock_irq(&fa->fa_lock);
fa->fa_fd = fd;
spin_unlock_irq(&fa->fa_lock);
goto out;
}
spin_lock_init(&new->fa_lock);
new->magic = FASYNC_MAGIC;
new->fa_file = filp;
new->fa_fd = fd;
new->fa_next = *fapp;
rcu_assign_pointer(*fapp, new);
filp->f_flags |= FASYNC;
out:
spin_unlock(&fasync_lock);
spin_unlock(&filp->f_lock);
return fa;
}
/*
* Add a fasync entry. Return negative on error, positive if
* added, and zero if did nothing but change an existing one.
*/
static int fasync_add_entry(int fd, struct file *filp, struct fasync_struct **fapp)
{
struct fasync_struct *new;
new = fasync_alloc();
if (!new)
return -ENOMEM;
/*
* fasync_insert_entry() returns the old (update) entry if
* it existed.
*
* So free the (unused) new entry and return 0 to let the
* caller know that we didn't add any new fasync entries.
*/
if (fasync_insert_entry(fd, filp, fapp, new)) {
fasync_free(new);
return 0;
}
return 1;
}
/*
* fasync_helper() is used by almost all character device drivers
* to set up the fasync queue, and for regular files by the file
* lease code. It returns negative on error, 0 if it did no changes
* and positive if it added/deleted the entry.
*/
int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp)
{
if (!on)
return fasync_remove_entry(filp, fapp);
return fasync_add_entry(fd, filp, fapp);
}
EXPORT_SYMBOL(fasync_helper);
/*
* rcu_read_lock() is held
*/
static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band)
{
while (fa) {
struct fown_struct *fown;
unsigned long flags;
if (fa->magic != FASYNC_MAGIC) {
printk(KERN_ERR "kill_fasync: bad magic number in "
"fasync_struct!\n");
return;
}
spin_lock_irqsave(&fa->fa_lock, flags);
if (fa->fa_file) {
fown = &fa->fa_file->f_owner;
/* Don't send SIGURG to processes which have not set a
queued signum: SIGURG has its own default signalling
mechanism. */
if (!(sig == SIGURG && fown->signum == 0))
send_sigio(fown, fa->fa_fd, band);
}
spin_unlock_irqrestore(&fa->fa_lock, flags);
fa = rcu_dereference(fa->fa_next);
}
}
void kill_fasync(struct fasync_struct **fp, int sig, int band)
{
/* First a quick test without locking: usually
* the list is empty.
*/
if (*fp) {
rcu_read_lock();
kill_fasync_rcu(rcu_dereference(*fp), sig, band);
rcu_read_unlock();
}
}
EXPORT_SYMBOL(kill_fasync);
static int __init fcntl_init(void)
{
/*
* Please add new bits here to ensure allocation uniqueness.
* Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDELAY
* is defined as O_NONBLOCK on some platforms and not on others.
*/
BUILD_BUG_ON(21 - 1 /* for O_RDONLY being 0 */ !=
HWEIGHT32(
(VALID_OPEN_FLAGS & ~(O_NONBLOCK | O_NDELAY)) |
__FMODE_EXEC | __FMODE_NONOTIFY));
fasync_cache = kmem_cache_create("fasync_cache",
sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL);
return 0;
}
module_init(fcntl_init)
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