Re: [PATCH] V1 2/2] ipc: let message queues use SIGEV_THREAD_ID with mq_notify
Any one who wants a quick way to test the changes can use the
following hacky program that works as an init program.
Thank you,
Steven Stewart-Gallus
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
/* GLibc does not expose sigev_notify_thread_id so we hack it in manually */
#ifndef __ARCH_SIGEV_PREAMBLE_SIZE
#define __ARCH_SIGEV_PREAMBLE_SIZE (sizeof(int) * 2 + sizeof(sigval_t))
#endif
#define SIGEV_MAX_SIZE 64
#define SIGEV_PAD_SIZE ((SIGEV_MAX_SIZE - __ARCH_SIGEV_PREAMBLE_SIZE) \
/ sizeof(int))
struct my_sigevent {
sigval_t sigev_value;
int sigev_signo;
int sigev_notify;
union {
int _pad[SIGEV_PAD_SIZE];
int _tid;
struct {
void (*_function)(sigval_t);
void *_attribute; /* really pthread_attr_t */
} _sigev_thread;
} _sigev_un;
};
#define sigev_notify_function _sigev_un._sigev_thread._function
#define sigev_notify_attributes _sigev_un._sigev_thread._attribute
#define sigev_notify_thread_id _sigev_un._tid
struct message {
int number;
};
static mqd_t mq;
static pid_t gettid(void)
{
return syscall(__NR_gettid);
}
static void * start_routine(void * arg)
{
{
struct message message = {
.number = 4
};
if (-1 == mq_send(mq, (char*), sizeof message, 0)) {
perror("mq_send");
_Exit(EXIT_FAILURE);
}
}
{
struct message message = {
.number = 5
};
if (-1 == mq_send(mq, (char*), sizeof message, 0)) {
perror("mq_send");
_Exit(EXIT_FAILURE);
}
}
{
struct message message = {
.number = 0
};
if (-1 == mq_send(mq, (char*), sizeof message, 0)) {
perror("mq_send");
_Exit(EXIT_FAILURE);
}
}
return NULL;
}
int main(int argc, char *argv[])
{
int errnum;
/* Fork to allow signals to be received */
{
pid_t child = fork();
if (-1 == child) {
perror("fork");
return EXIT_FAILURE;
}
if (child != 0) {
siginfo_t info;
do {
errnum = -1 == waitid(P_PID, child, ,
WEXITED) ? errno : 0;
} while (EINTR == errnum);
if (errnum != 0) {
assert(errnum != EINVAL);
assert(errnum != ECHILD);
assert(false);
}
reboot(RB_POWER_OFF);
}
}
{
struct mq_attr attr = { 0 };
attr.mq_maxmsg = 8U;
attr.mq_msgsize = sizeof (struct message);
mq = mq_open("/foo", O_RDWR | O_CREAT | O_EXCL | O_NONBLOCK, 0,
);
}
if (-1 == mq) {
perror("mq_open");
return EXIT_FAILURE;
}
sigset_t rtset;
sigemptyset();
sigaddset(, SIGRTMIN);
pthread_sigmask(SIG_BLOCK, , NULL);
pthread_t worker;
if ((errnum = pthread_create(, NULL, start_routine, NULL)) != 0)
{
errno = errnum;
perror("pthread_create");
return EXIT_FAILURE;
}
for (;;) {
{
struct my_sigevent sev = { 0 };
sev.sigev_notify = SIGEV_THREAD_ID;
sev.sigev_signo = SIGRTMIN;
sev.sigev_notify_thread_id = gettid();
if (-1 == mq_notify(mq,(struct sigevent*) )) {
perror("mq_notify");
return EXIT_FAILURE;
}
}
for (;;) {
struct message message;
if (-1 == mq_receive(mq, (char*), sizeof
message, 0)) {
errnum = errno;
} else {
errnum = 0;
}
if (EAGAIN == errnum) {
break;
}
if (errnum != 0) {
errno = errnum;
perror("mq_receive");
return EXIT_FAILURE;
}
[PATCH] V1 2/2] ipc: let message queues use SIGEV_THREAD_ID with mq_notify
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 4fcf39a..8ca70a2 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -88,7 +88,7 @@ struct mqueue_inode_info {
static const struct inode_operations mqueue_dir_inode_operations;
static const struct file_operations mqueue_file_operations;
static const struct super_operations mqueue_super_ops;
-static void remove_notification(struct mqueue_inode_info *info);
+static bool maybe_remove_notification(struct mqueue_inode_info *info);
static struct kmem_cache *mqueue_inode_cachep;
@@ -495,7 +495,8 @@ static ssize_t mqueue_read_file(struct file *filp, char
__user *u_data,
info->qsize,
info->notify_owner ? info->notify.sigev_notify : 0,
(info->notify_owner &&
-info->notify.sigev_notify == SIGEV_SIGNAL) ?
+(info->notify.sigev_notify == SIGEV_SIGNAL ||
+ info->notify.sigev_notify == SIGEV_THREAD_ID)) ?
info->notify.sigev_signo : 0,
pid_vnr(info->notify_owner));
spin_unlock(>lock);
@@ -515,8 +516,8 @@ static int mqueue_flush_file(struct file *filp, fl_owner_t
id)
struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
spin_lock(>lock);
- if (task_tgid(current) == info->notify_owner)
- remove_notification(info);
+
+ maybe_remove_notification(info);
spin_unlock(>lock);
return 0;
@@ -642,6 +643,7 @@ static void __do_notify(struct mqueue_inode_info *info)
case SIGEV_NONE:
break;
case SIGEV_SIGNAL:
+ case SIGEV_THREAD_ID:
/* sends signal */
sig_i.si_signo = info->notify.sigev_signo;
@@ -684,8 +686,24 @@ static int prepare_timeout(const struct timespec __user
*u_abs_timeout,
return 0;
}
-static void remove_notification(struct mqueue_inode_info *info)
+static bool maybe_remove_notification(struct mqueue_inode_info *info)
{
+ struct pid *pid;
+
+ switch (info->notify.sigev_notify) {
+ case SIGEV_THREAD_ID:
+ pid = task_pid(current);
+ break;
+
+ default:
+ pid = task_tgid(current);
+ break;
+ }
+
+ if (pid != info->notify_owner) {
+ return false;
+ }
+
if (info->notify_owner != NULL &&
info->notify.sigev_notify == SIGEV_THREAD) {
set_cookie(info->notify_cookie, NOTIFY_REMOVED);
@@ -695,6 +713,8 @@ static void remove_notification(struct mqueue_inode_info
*info)
put_user_ns(info->notify_user_ns);
info->notify_owner = NULL;
info->notify_user_ns = NULL;
+
+ return true;
}
static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
@@ -1203,12 +1223,18 @@ SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
if (u_notification != NULL) {
if (unlikely(notification.sigev_notify != SIGEV_NONE &&
notification.sigev_notify != SIGEV_SIGNAL &&
-notification.sigev_notify != SIGEV_THREAD))
+notification.sigev_notify != SIGEV_THREAD &&
+notification.sigev_notify != SIGEV_THREAD_ID))
return -EINVAL;
- if (notification.sigev_notify == SIGEV_SIGNAL &&
+ if ((notification.sigev_notify == SIGEV_SIGNAL ||
+notification.sigev_notify == SIGEV_THREAD_ID) &&
!valid_signal(notification.sigev_signo)) {
return -EINVAL;
}
+ if (notification.sigev_notify == SIGEV_THREAD_ID &&
+ notification.sigev_notify_thread_id <= 0) {
+ return -EINVAL;
+ }
if (notification.sigev_notify == SIGEV_THREAD) {
long timeo;
@@ -1270,8 +1296,7 @@ retry:
ret = 0;
spin_lock(>lock);
if (u_notification == NULL) {
- if (info->notify_owner == task_tgid(current)) {
- remove_notification(info);
+ if (maybe_remove_notification(info)) {
inode->i_atime = inode->i_ctime = CURRENT_TIME;
}
} else if (info->notify_owner != NULL) {
@@ -1286,16 +1311,39 @@ retry:
info->notify_cookie = nc;
sock = NULL;
nc = NULL;
+ info->notify_owner = get_pid(task_tgid(current));
info->notify.sigev_notify = SIGEV_THREAD;
break;
case SIGEV_SIGNAL:
info->notify.sigev_signo = notification.sigev_signo;
info->notify.sigev_value = notification.sigev_value;
+
[PATCH] V1 2/2] ipc: let message queues use SIGEV_THREAD_ID with mq_notify
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 4fcf39a..8ca70a2 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -88,7 +88,7 @@ struct mqueue_inode_info {
static const struct inode_operations mqueue_dir_inode_operations;
static const struct file_operations mqueue_file_operations;
static const struct super_operations mqueue_super_ops;
-static void remove_notification(struct mqueue_inode_info *info);
+static bool maybe_remove_notification(struct mqueue_inode_info *info);
static struct kmem_cache *mqueue_inode_cachep;
@@ -495,7 +495,8 @@ static ssize_t mqueue_read_file(struct file *filp, char
__user *u_data,
info-qsize,
info-notify_owner ? info-notify.sigev_notify : 0,
(info-notify_owner
-info-notify.sigev_notify == SIGEV_SIGNAL) ?
+(info-notify.sigev_notify == SIGEV_SIGNAL ||
+ info-notify.sigev_notify == SIGEV_THREAD_ID)) ?
info-notify.sigev_signo : 0,
pid_vnr(info-notify_owner));
spin_unlock(info-lock);
@@ -515,8 +516,8 @@ static int mqueue_flush_file(struct file *filp, fl_owner_t
id)
struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
spin_lock(info-lock);
- if (task_tgid(current) == info-notify_owner)
- remove_notification(info);
+
+ maybe_remove_notification(info);
spin_unlock(info-lock);
return 0;
@@ -642,6 +643,7 @@ static void __do_notify(struct mqueue_inode_info *info)
case SIGEV_NONE:
break;
case SIGEV_SIGNAL:
+ case SIGEV_THREAD_ID:
/* sends signal */
sig_i.si_signo = info-notify.sigev_signo;
@@ -684,8 +686,24 @@ static int prepare_timeout(const struct timespec __user
*u_abs_timeout,
return 0;
}
-static void remove_notification(struct mqueue_inode_info *info)
+static bool maybe_remove_notification(struct mqueue_inode_info *info)
{
+ struct pid *pid;
+
+ switch (info-notify.sigev_notify) {
+ case SIGEV_THREAD_ID:
+ pid = task_pid(current);
+ break;
+
+ default:
+ pid = task_tgid(current);
+ break;
+ }
+
+ if (pid != info-notify_owner) {
+ return false;
+ }
+
if (info-notify_owner != NULL
info-notify.sigev_notify == SIGEV_THREAD) {
set_cookie(info-notify_cookie, NOTIFY_REMOVED);
@@ -695,6 +713,8 @@ static void remove_notification(struct mqueue_inode_info
*info)
put_user_ns(info-notify_user_ns);
info-notify_owner = NULL;
info-notify_user_ns = NULL;
+
+ return true;
}
static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
@@ -1203,12 +1223,18 @@ SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
if (u_notification != NULL) {
if (unlikely(notification.sigev_notify != SIGEV_NONE
notification.sigev_notify != SIGEV_SIGNAL
-notification.sigev_notify != SIGEV_THREAD))
+notification.sigev_notify != SIGEV_THREAD
+notification.sigev_notify != SIGEV_THREAD_ID))
return -EINVAL;
- if (notification.sigev_notify == SIGEV_SIGNAL
+ if ((notification.sigev_notify == SIGEV_SIGNAL ||
+notification.sigev_notify == SIGEV_THREAD_ID)
!valid_signal(notification.sigev_signo)) {
return -EINVAL;
}
+ if (notification.sigev_notify == SIGEV_THREAD_ID
+ notification.sigev_notify_thread_id = 0) {
+ return -EINVAL;
+ }
if (notification.sigev_notify == SIGEV_THREAD) {
long timeo;
@@ -1270,8 +1296,7 @@ retry:
ret = 0;
spin_lock(info-lock);
if (u_notification == NULL) {
- if (info-notify_owner == task_tgid(current)) {
- remove_notification(info);
+ if (maybe_remove_notification(info)) {
inode-i_atime = inode-i_ctime = CURRENT_TIME;
}
} else if (info-notify_owner != NULL) {
@@ -1286,16 +1311,39 @@ retry:
info-notify_cookie = nc;
sock = NULL;
nc = NULL;
+ info-notify_owner = get_pid(task_tgid(current));
info-notify.sigev_notify = SIGEV_THREAD;
break;
case SIGEV_SIGNAL:
info-notify.sigev_signo = notification.sigev_signo;
info-notify.sigev_value = notification.sigev_value;
+ info-notify_owner =
Re: [PATCH] V1 2/2] ipc: let message queues use SIGEV_THREAD_ID with mq_notify
Any one who wants a quick way to test the changes can use the
following hacky program that works as an init program.
Thank you,
Steven Stewart-Gallus
#include assert.h
#include errno.h
#include fcntl.h
#include mqueue.h
#include pthread.h
#include signal.h
#include stdbool.h
#include stdio.h
#include stdlib.h
#include sys/reboot.h
#include sys/syscall.h
#include sys/wait.h
#include unistd.h
/* GLibc does not expose sigev_notify_thread_id so we hack it in manually */
#ifndef __ARCH_SIGEV_PREAMBLE_SIZE
#define __ARCH_SIGEV_PREAMBLE_SIZE (sizeof(int) * 2 + sizeof(sigval_t))
#endif
#define SIGEV_MAX_SIZE 64
#define SIGEV_PAD_SIZE ((SIGEV_MAX_SIZE - __ARCH_SIGEV_PREAMBLE_SIZE) \
/ sizeof(int))
struct my_sigevent {
sigval_t sigev_value;
int sigev_signo;
int sigev_notify;
union {
int _pad[SIGEV_PAD_SIZE];
int _tid;
struct {
void (*_function)(sigval_t);
void *_attribute; /* really pthread_attr_t */
} _sigev_thread;
} _sigev_un;
};
#define sigev_notify_function _sigev_un._sigev_thread._function
#define sigev_notify_attributes _sigev_un._sigev_thread._attribute
#define sigev_notify_thread_id _sigev_un._tid
struct message {
int number;
};
static mqd_t mq;
static pid_t gettid(void)
{
return syscall(__NR_gettid);
}
static void * start_routine(void * arg)
{
{
struct message message = {
.number = 4
};
if (-1 == mq_send(mq, (char*)message, sizeof message, 0)) {
perror(mq_send);
_Exit(EXIT_FAILURE);
}
}
{
struct message message = {
.number = 5
};
if (-1 == mq_send(mq, (char*)message, sizeof message, 0)) {
perror(mq_send);
_Exit(EXIT_FAILURE);
}
}
{
struct message message = {
.number = 0
};
if (-1 == mq_send(mq, (char*)message, sizeof message, 0)) {
perror(mq_send);
_Exit(EXIT_FAILURE);
}
}
return NULL;
}
int main(int argc, char *argv[])
{
int errnum;
/* Fork to allow signals to be received */
{
pid_t child = fork();
if (-1 == child) {
perror(fork);
return EXIT_FAILURE;
}
if (child != 0) {
siginfo_t info;
do {
errnum = -1 == waitid(P_PID, child, info,
WEXITED) ? errno : 0;
} while (EINTR == errnum);
if (errnum != 0) {
assert(errnum != EINVAL);
assert(errnum != ECHILD);
assert(false);
}
reboot(RB_POWER_OFF);
}
}
{
struct mq_attr attr = { 0 };
attr.mq_maxmsg = 8U;
attr.mq_msgsize = sizeof (struct message);
mq = mq_open(/foo, O_RDWR | O_CREAT | O_EXCL | O_NONBLOCK, 0,
attr);
}
if (-1 == mq) {
perror(mq_open);
return EXIT_FAILURE;
}
sigset_t rtset;
sigemptyset(rtset);
sigaddset(rtset, SIGRTMIN);
pthread_sigmask(SIG_BLOCK, rtset, NULL);
pthread_t worker;
if ((errnum = pthread_create(worker, NULL, start_routine, NULL)) != 0)
{
errno = errnum;
perror(pthread_create);
return EXIT_FAILURE;
}
for (;;) {
{
struct my_sigevent sev = { 0 };
sev.sigev_notify = SIGEV_THREAD_ID;
sev.sigev_signo = SIGRTMIN;
sev.sigev_notify_thread_id = gettid();
if (-1 == mq_notify(mq,(struct sigevent*) sev)) {
perror(mq_notify);
return EXIT_FAILURE;
}
}
for (;;) {
struct message message;
if (-1 == mq_receive(mq, (char*)message, sizeof
message, 0)) {
errnum = errno;
} else {
errnum = 0;
}
if (EAGAIN == errnum) {
break;
}
if (errnum != 0) {
errno = errnum;
