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[RFC PATCH 0/5] IPC: CRIU enhancements update [message #48635] Fri, 26 October 2012 11:05 Go to next message
Stanislav Kinsbursky is currently offline  Stanislav Kinsbursky
Messages: 683
Registered: October 2011
Senior Member
From: *parallels.com
This patch set is aimed to fix some errors in previously commited "[RFC PATCH
v8 0/5] IPC: checkpoint/restore in userspace enhancements" patch set.

Is particular it:
1) wraps new sysctl in CONFIG_CHECKPOINT_RESTORE macro and updates
documentation
2) fixes self-test to work with new sysctls.
3) cleanup do_msgrcv() to make it looks less ugly aroung MSG_COPY feature.

The following series implements...

---

Stanislav Kinsbursky (5):
ipc: wrap new sysctls for CRIU inside CONFIG_CHECKPOINT_RESTORE
ipc: remove redundant MSG_COPY check
test: IPC message queue copy feature test update
Documentation: update sysctl/kernel.txt
ipc: cleanup do_msgrcv() aroung MSG_COPY feature


Documentation/sysctl/kernel.txt | 19 ++++++++
include/linux/msg.h | 3 +
ipc/compat.c | 3 +
ipc/ipc_sysctl.c | 4 ++
ipc/msg.c | 84 ++++++++++++++++++++--------------
ipc/util.c | 2 -
tools/testing/selftests/ipc/msgque.c | 83 ++++++++++++++++++++--------------
7 files changed, 126 insertions(+), 72 deletions(-)
[PATCH 1/5] ipc: wrap new sysctls for CRIU inside CONFIG_CHECKPOINT_RESTORE [message #48636 is a reply to message #48635] Fri, 26 October 2012 11:05 Go to previous messageGo to next message
Stanislav Kinsbursky is currently offline  Stanislav Kinsbursky
Messages: 683
Registered: October 2011
Senior Member
From: *parallels.com
This patch set wraps "msg_next_id", "sem_next_id" and "shm_next_id" inside
CONFIG_CHECKPOINT_RESTORE macro.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
---
ipc/ipc_sysctl.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
index d06d77a..130dfec 100644
--- a/ipc/ipc_sysctl.c
+++ b/ipc/ipc_sysctl.c
@@ -158,7 +158,9 @@ static int proc_ipcauto_dointvec_minmax(ctl_table *table, int write,

static int zero;
static int one = 1;
+#ifdef CONFIG_CHECKPOINT_RESTORE
static int int_max = INT_MAX;
+#endif

static struct ctl_table ipc_kern_table[] = {
{
@@ -228,6 +230,7 @@ static struct ctl_table ipc_kern_table[] = {
.extra1 = &zero,
.extra2 = &one,
},
+#ifdef CONFIG_CHECKPOINT_RESTORE
{
.procname = "sem_next_id",
.data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id,
@@ -255,6 +258,7 @@ static struct ctl_table ipc_kern_table[] = {
.extra1 = &zero,
.extra2 = &int_max,
},
+#endif
{}
};
[PATCH 5/5] ipc: cleanup do_msgrcv() aroung MSG_COPY feature [message #48637 is a reply to message #48635] Fri, 26 October 2012 11:06 Go to previous message
Stanislav Kinsbursky is currently offline  Stanislav Kinsbursky
Messages: 683
Registered: October 2011
Senior Member
From: *parallels.com
MSG_COPY feature was developed for Checkpoint/Restart In User space project
and thus wrapped in CONFIG_CHECKPOINT_RESTORE macro. But code look a bit ugly.
So this patch is an attempt to cleanup do_msgrcv() a bit and make it looks
better.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
---
ipc/msg.c | 79 +++++++++++++++++++++++++++++++++++++----------------------- -
1 files changed, 48 insertions(+), 31 deletions(-)

diff --git a/ipc/msg.c b/ipc/msg.c
index 91873df..d20ffc7 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -769,6 +769,45 @@ static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
return msgsz;
}

+#ifdef CONFIG_CHECKPOINT_RESTORE
+static inline struct msg_msg *fill_copy(unsigned long copy_nr,
+ unsigned long msg_nr,
+ struct msg_msg *msg,
+ struct msg_msg *copy)
+{
+ if (copy_nr == msg_nr)
+ return copy_msg(msg, copy);
+ return NULL;
+}
+
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz,
+ int msgflg, long *msgtyp,
+ unsigned long *copy_number)
+{
+ struct msg_msg *copy;
+
+ *copy_number = *msgtyp;
+ *msgtyp = 0;
+ /*
+ * Create dummy message to copy real message to.
+ */
+ copy = load_msg(buf, bufsz);
+ if (!IS_ERR(copy))
+ copy->m_ts = bufsz;
+ return copy;
+}
+
+static inline void free_copy(int msgflg, struct msg_msg *copy)
+{
+ if (msgflg & MSG_COPY)
+ free_msg(copy);
+}
+#else
+#define free_copy(msgflg, copy) do {} while (0)
+#define prepare_copy(buf, sz, msgflg, msgtyp, copy_nr) ERR_PTR(-ENOSYS)
+#define fill_copy(copy_nr, msg_nr, msg, copy) NULL
+#endif
+
long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
int msgflg,
long (*msg_handler)(void __user *, struct msg_msg *, size_t))
@@ -777,38 +816,22 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
struct msg_msg *msg;
int mode;
struct ipc_namespace *ns;
-#ifdef CONFIG_CHECKPOINT_RESTORE
- struct msg_msg *copy = NULL;
- unsigned long copy_number = 0;
-#endif
+ struct msg_msg *copy;
+ unsigned long __maybe_unused copy_number;

if (msqid < 0 || (long) bufsz < 0)
return -EINVAL;
if (msgflg & MSG_COPY) {
-#ifdef CONFIG_CHECKPOINT_RESTORE
- copy_number = msgtyp;
- msgtyp = 0;
-
- /*
- * Create dummy message to copy real message to.
- */
- copy = load_msg(buf, bufsz);
+ copy = prepare_copy(buf, bufsz, msgflg, &msgtyp, &copy_number);
if (IS_ERR(copy))
return PTR_ERR(copy);
- copy->m_ts = bufsz;
-#else
- return -ENOSYS;
-#endif
}
mode = convert_mode(&msgtyp, msgflg);
ns = current->nsproxy->ipc_ns;

msq = msg_lock_check(ns, msqid);
if (IS_ERR(msq)) {
-#ifdef CONFIG_CHECKPOINT_RESTORE
- if (msgflg & MSG_COPY)
- free_msg(copy);
-#endif
+ free_copy(msgflg, copy);
return PTR_ERR(msq);
}

@@ -835,13 +858,12 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
if (mode == SEARCH_LESSEQUAL &&
walk_msg->m_type != 1) {
msgtyp = walk_msg->m_type - 1;
-#ifdef CONFIG_CHECKPOINT_RESTORE
} else if (msgflg & MSG_COPY) {
- if (copy_number == msg_counter) {
- msg = copy_msg(walk_msg, copy);
+ msg = fill_copy(copy_number,
+ msg_counter,
+ walk_msg, copy);
+ if (msg)
break;
- }
-#endif
} else
break;
msg_counter++;
@@ -857,10 +879,8 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
msg = ERR_PTR(-E2BIG);
goto out_unlock;
}
-#ifdef CONFIG_CHECKPOINT_RESTORE
if (msgflg & MSG_COPY)
goto out_unlock;
-#endif
list_del(&msg->m_list);
msq->q_qnum--;
msq->q_rtime = get_seconds();
@@ -945,10 +965,7 @@ out_unlock:
}
}
if (IS_ERR(msg)) {
-#ifdef CONFIG_CHECKPOINT_RESTORE
- if (msgflg & MSG_COPY)
- free_msg(copy);
-#endif
+ free_copy(msgflg, copy);
return PTR_ERR(msg);
}
[PATCH 4/5] Documentation: update sysctl/kernel.txt [message #48638 is a reply to message #48635] Fri, 26 October 2012 11:06 Go to previous message
Stanislav Kinsbursky is currently offline  Stanislav Kinsbursky
Messages: 683
Registered: October 2011
Senior Member
From: *parallels.com
This patch adds documentation about new "msg_next_id", "sem_next_id" and
"shm_next_id" sysctls.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
---
Documentation/sysctl/kernel.txt | 19 +++++++++++++++++++
1 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 2907ba6..51b953a 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -38,6 +38,7 @@ show up in /proc/sys/kernel:
- l2cr [ PPC only ]
- modprobe ==> Documentation/debugging-modules.txt
- modules_disabled
+- msg_next_id [ sysv ipc ]
- msgmax
- msgmnb
- msgmni
@@ -62,7 +63,9 @@ show up in /proc/sys/kernel:
- rtsig-max
- rtsig-nr
- sem
+- sem_next_id [ sysv ipc ]
- sg-big-buff [ generic SCSI device (sg) ]
+- shm_next_id [ sysv ipc ]
- shm_rmid_forced
- shmall
- shmmax [ sysv ipc ]
@@ -320,6 +323,22 @@ to false.

============================================================ ==

+msg_next_id, sem_next_id, and shm_next_id:
+
+These three toggles allows to specify desired id for next allocated IPC
+object: message, semaphore or shared memory respectively.
+
+By default they are equal to -1, which means generic allocation logic.
+Possible values to set are in range {0..INT_MAX}.
+
+Notes:
+1) kernel doesn't guarantee, that new object will have desired id. So,
+it's up to userspace, how to handle an object with "wrong" id.
+2) Toggle with non-default value will be set back to -1 by kernel after
+successful IPC object allocation.
+
+=========================================================== ===
+
nmi_watchdog:

Enables/Disables the NMI watchdog on x86 systems. When the value is
[PATCH 3/5] test: IPC message queue copy feature test update [message #48639 is a reply to message #48635] Fri, 26 October 2012 11:06 Go to previous message
Stanislav Kinsbursky is currently offline  Stanislav Kinsbursky
Messages: 683
Registered: October 2011
Senior Member
From: *parallels.com
This update fixes coding style problems (80-characters line and others).
Also, it fixes test to work with new IPC sysctls (instead of using
experimental API logic, which was throwed away and replaced by sysctls).

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
---
include/linux/msg.h | 3 +
ipc/compat.c | 3 +
ipc/msg.c | 2 -
ipc/util.c | 2 -
tools/testing/selftests/ipc/msgque.c | 83 ++++++++++++++++++++--------------
5 files changed, 55 insertions(+), 38 deletions(-)

diff --git a/include/linux/msg.h b/include/linux/msg.h
index f38edba..391af8d 100644
--- a/include/linux/msg.h
+++ b/include/linux/msg.h
@@ -36,6 +36,7 @@ extern long do_msgsnd(int msqid, long mtype, void __user *mtext,
size_t msgsz, int msgflg);
extern long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
int msgflg,
- long (*msg_fill)(void __user *, struct msg_msg *, size_t ));
+ long (*msg_fill)(void __user *, struct msg_msg *,
+ size_t));

#endif /* _LINUX_MSG_H */
diff --git a/ipc/compat.c b/ipc/compat.c
index eb3ea16..2547f29 100644
--- a/ipc/compat.c
+++ b/ipc/compat.c
@@ -365,7 +365,8 @@ long compat_sys_msgrcv(int first, int second, int msgtyp, int third,
uptr = compat_ptr(ipck.msgp);
msgtyp = ipck.msgtyp;
}
- return do_msgrcv(first, uptr, second, msgtyp, third, compat_do_msg_fill);
+ return do_msgrcv(first, uptr, second, msgtyp, third,
+ compat_do_msg_fill);
}
#else
long compat_sys_semctl(int semid, int semnum, int cmd, int arg)
diff --git a/ipc/msg.c b/ipc/msg.c
index f9774ff..91873df 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -771,7 +771,7 @@ static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)

long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
int msgflg,
- long (*msg_handler)(void __user *, struct msg_msg *, size_t ))
+ long (*msg_handler)(void __user *, struct msg_msg *, size_t))
{
struct msg_queue *msq;
struct msg_msg *msg;
diff --git a/ipc/util.c b/ipc/util.c
index a961e46..74e1d9c 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -282,7 +282,7 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)

if (next_id < 0) {
new->seq = ids->seq++;
- if(ids->seq > ids->seq_max)
+ if (ids->seq > ids->seq_max)
ids->seq = 0;
} else {
new->seq = ipcid_to_seqx(next_id);
diff --git a/tools/testing/selftests/ipc/msgque.c b/tools/testing/selftests/ipc/msgque.c
index e2d6a64..d664182 100644
--- a/tools/testing/selftests/ipc/msgque.c
+++ b/tools/testing/selftests/ipc/msgque.c
@@ -3,6 +3,7 @@
#include <string.h>
#include <errno.h>
#include <linux/msg.h>
+#include <fcntl.h>

#define MAX_MSG_SIZE 32

@@ -19,9 +20,9 @@ struct msg1 {
#define ANOTHER_MSG_TYPE 26538

struct msgque_data {
+ key_t key;
int msq_id;
int qbytes;
- int kern_id;
int qnum;
int mode;
struct msg1 *messages;
@@ -29,41 +30,49 @@ struct msgque_data {

int restore_queue(struct msgque_data *msgque)
{
- struct msqid_ds ds;
- int id, i;
+ int fd, ret, id, i;
+ char buf[32];

- id = msgget(msgque->msq_id,
- msgque->mode | IPC_CREAT | IPC_EXCL | IPC_PRESET);
- if (id == -1) {
- printf("Failed to create queue\n");
+ fd = open("/proc/sys/kernel/msg_next_id", O_WRONLY);
+ if (fd == -1) {
+ printf("Failed to open /proc/sys/kernel/msg_next_id\n");
return -errno;
}
+ sprintf(buf, "%d", msgque->msq_id);

- if (id != msgque->msq_id) {
- printf("Failed to preset id (%d instead of %d)\n",
- id, msgque->msq_id);
- return -EFAULT;
+ ret = write(fd, buf, strlen(buf));
+ if (ret != strlen(buf)) {
+ printf("Failed to write to /proc/sys/kernel/msg_next_id\n");
+ return -errno;
}

- if (msgctl(id, MSG_STAT, &ds) < 0) {
- printf("Failed to stat queue\n");
+ id = msgget(msgque->key, msgque->mode | IPC_CREAT | IPC_EXCL);
+ if (id == -1) {
+ printf("Failed to create queue\n");
return -errno;
}

- ds.msg_perm.key = msgque->msq_id;
- ds.msg_qbytes = msgque->qbytes;
- if (msgctl(id, MSG_SET, &ds) < 0) {
- printf("Failed to update message key\n");
- return -errno;
+ if (id != msgque->msq_id) {
+ printf("Restored queue has wrong id (%d instead of %d)\n",
+ id, msgque->msq_id);
+ ret = -EFAULT;
+ goto destroy;
}

for (i = 0; i < msgque->qnum; i++) {
- if (msgsnd(msgque->msq_id, &msgque->messages[i].mtype, msgque->messages[i].msize, IPC_NOWAIT) != 0) {
+ if (msgsnd(msgque->msq_id, &msgque->messages[i].mtype,
+ msgque->messages[i].msize, IPC_NOWAIT) != 0) {
printf("msgsnd failed (%m)\n");
- return -errno;
+ ret = -errno;
+ goto destroy;
};
}
return 0;
+
+destroy:
+ if (msgctl(id, IPC_RMID, 0))
+ printf("Failed to destroy queue: %d\n", -errno);
+ return ret;
}

int check_and_destroy_queue(struct msgque_data *msgque)
@@ -72,7 +81,8 @@ int check_and_destroy_queue(struct msgque_data *msgque)
int cnt = 0, ret;

while (1) {
- ret = msgrcv(msgque->msq_id, &message.mtype, MAX_MSG_SIZE, 0, IPC_NOWAIT);
+ ret = msgrcv(msgque->msq_id, &message.mtype, MAX_MSG_SIZE,
+ 0, IPC_NOWAIT);
if (ret < 0) {
if (errno == ENOMSG)
break;
@@ -81,7 +91,8 @@ int check_and_destroy_queue(struct msgque_data *msgque)
goto err;
}
if (ret != msgque->messages[cnt].msize) {
- printf("Wrong message size: %d (expected %d)\n", ret, msgque->messages[cnt].msize);
+ printf("Wrong message size: %d (expected %d)\n", ret,
+ msgque->messages[cnt].msize);
ret = -EINVAL;
goto err;
}
@@ -115,15 +126,17 @@ err:

int dump_queue(struct msgque_data *msgque)
{
- struct msqid_ds ds;
+ struct msqid64_ds ds;
+ int kern_id;
int i, ret;

- for (msgque->kern_id = 0; msgque->kern_id < 256; msgque->kern_id++) {
- ret = msgctl(msgque->kern_id, MSG_STAT, &ds);
+ for (kern_id = 0; kern_id < 256; kern_id++) {
+ ret = msgctl(kern_id, MSG_STAT, &ds);
if (ret < 0) {
if (errno == -EINVAL)
continue;
- printf("Failed to get stats for IPC queue with id %d\n", msgque->kern_id);
+ printf("Failed to get stats for IPC queue with id %d\n",
+ kern_id);
return -errno;
}

@@ -142,7 +155,8 @@ int dump_queue(struct msgque_data *msgque)
msgque->qbytes = ds.msg_qbytes;

for (i = 0; i < msgque->qnum; i++) {
- ret = msgrcv(msgque->msq_id, &msgque->messages[i].mtype, MAX_MSG_SIZE, i, IPC_NOWAIT | MSG_COPY);
+ ret = msgrcv(msgque->msq_id, &msgque->messages[i].mtype,
+ MAX_MSG_SIZE, i, IPC_NOWAIT | MSG_COPY);
if (ret < 0) {
printf("Failed to copy IPC message: %m (%d)\n", errno);
return -errno;
@@ -158,33 +172,34 @@ int fill_msgque(struct msgque_data *msgque)

msgbuf.mtype = MSG_TYPE;
memcpy(msgbuf.mtext, TEST_STRING, sizeof(TEST_STRING));
- if (msgsnd(msgque->msq_id, &msgbuf.mtype, sizeof(TEST_STRING), IPC_NOWAIT) != 0) {
+ if (msgsnd(msgque->msq_id, &msgbuf.mtype, sizeof(TEST_STRING),
+ IPC_NOWAIT) != 0) {
printf("First message send failed (%m)\n");
return -errno;
};

msgbuf.mtype = ANOTHER_MSG_TYPE;
memcpy(msgbuf.mtext, ANOTHER_TEST_STRING, sizeof(ANOTHER_TEST_STRING));
- if (msgsnd(msgque->msq_id, &msgbuf.mtype, sizeof(ANOTHER_TEST_STRING), IPC_NOWAIT) != 0) {
+ if (msgsnd(msgque->msq_id, &msgbuf.mtype, sizeof(ANOTHER_TEST_STRING),
+ IPC_NOWAIT) != 0) {
printf("Second message send failed (%m)\n");
return -errno;
};
return 0;
}

-int main (int argc, char **argv)
+int main(int argc, char **argv)
{
- key_t key;
int msg, pid, err;
struct msgque_data msgque;

- key = ftok(argv[0], 822155650);
- if (key == -1) {
+ msgque.key = ftok(argv[0], 822155650);
+ if (msgque.key == -1) {
printf("Can't make key\n");
return -errno;
}

- msgque.msq_id = msgget(key, IPC_CREAT | IPC_EXCL | 0666);
+ msgque.msq_id = msgget(msgque.key, IPC_CREAT | IPC_EXCL | 0666);
if (msgque.msq_id == -1) {
printf("Can't create queue\n");
goto err_out;
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