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[PATCH v6 07/10] ipc: add new SEM_SET command for sys_semctl() call [message #48355] Mon, 15 October 2012 16:00 Go to next message
Stanislav Kinsbursky is currently offline  Stanislav Kinsbursky
Messages: 683
Registered: October 2011
Senior Member
From: *parallels.com
New SEM_SET command will be interpreted exactly as IPC_SET, but also will
update key, cuid and cgid values. IOW, it allows to change existent key value.
The fact, that key is not used is checked before update. Otherwise -EEXIST is
returned.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
---
include/uapi/linux/sem.h | 1 +
ipc/compat.c | 1 +
ipc/sem.c | 10 ++++++++--
security/selinux/hooks.c | 1 +
security/smack/smack_lsm.c | 1 +
5 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/sem.h b/include/uapi/linux/sem.h
index 541fce0..b6ae374 100644
--- a/include/uapi/linux/sem.h
+++ b/include/uapi/linux/sem.h
@@ -18,6 +18,7 @@
/* ipcs ctl cmds */
#define SEM_STAT 18
#define SEM_INFO 19
+#define SEM_SET 20

/* Obsolete, used only for backwards compatibility and libc5 compiles */
struct semid_ds {
diff --git a/ipc/compat.c b/ipc/compat.c
index 9c70f9a..84d8efd 100644
--- a/ipc/compat.c
+++ b/ipc/compat.c
@@ -290,6 +290,7 @@ static long do_compat_semctl(int first, int second, int third, u32 pad)
break;

case IPC_SET:
+ case SEM_SET:
if (version == IPC_64) {
err = get_compat_semid64_ds(&s64, compat_ptr(pad));
} else {
diff --git a/ipc/sem.c b/ipc/sem.c
index 10e9085..3eac885 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -1085,12 +1085,13 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
struct semid64_ds semid64;
struct kern_ipc_perm *ipcp;

- if(cmd == IPC_SET) {
+ if (cmd == IPC_SET || cmd == SEM_SET) {
if (copy_semid_from_user(&semid64, arg.buf, version))
return -EFAULT;
}

- ipcp = ipcctl_pre_down(ns, &sem_ids(ns), semid, cmd,
+ ipcp = ipcctl_pre_down(ns, &sem_ids(ns), semid,
+ (cmd != SEM_SET) ? cmd : IPC_SET,
&semid64.sem_perm, 0);
if (IS_ERR(ipcp))
return PTR_ERR(ipcp);
@@ -1105,6 +1106,10 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
case IPC_RMID:
freeary(ns, ipcp);
goto out_up;
+ case SEM_SET:
+ err = ipc_update_key(&sem_ids(ns), &semid64.sem_perm, ipcp);
+ if (err)
+ break;
case IPC_SET:
err = ipc_update_perm(&semid64.sem_perm, ipcp);
if (err)
@@ -1152,6 +1157,7 @@ SYSCALL_DEFINE(semctl)(int semid, int semnum, int cmd, union semun arg)
return err;
case IPC_RMID:
case IPC_SET:
+ case SEM_SET:
err = semctl_down(ns, semid, cmd, version, arg);
return err;
default:
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 78b77ac..02b037d 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -5133,6 +5133,7 @@ static int selinux_sem_semctl(struct sem_array *sma, int cmd)
perms = SEM__DESTROY;
break;
case IPC_SET:
+ case SEM_SET:
perms = SEM__SETATTR;
break;
case IPC_STAT:
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index d51a8da..b4135ed 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -2253,6 +2253,7 @@ static int smack_sem_semctl(struct sem_array *sma, int cmd)
case SETALL:
case IPC_RMID:
case IPC_SET:
+ case SEM_SET:
may = MAY_READWRITE;
break;
case IPC_INFO:
Re: [PATCH v6 07/10] ipc: add new SEM_SET command for sys_semctl() call [message #48571 is a reply to message #48355] Tue, 23 October 2012 16:34 Go to previous message
Serge E. Hallyn is currently offline  Serge E. Hallyn
Messages: 26
Registered: February 2011
Junior Member
From: *parallels.com
Quoting Stanislav Kinsbursky (skinsbursky@parallels.com):
> New SEM_SET command will be interpreted exactly as IPC_SET, but also will
> update key, cuid and cgid values. IOW, it allows to change existent key value.
> The fact, that key is not used is checked before update. Otherwise -EEXIST is
> returned.
>
> Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>

Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

(again, modulo requested /* fallthrough */ comment )

> ---
> include/uapi/linux/sem.h | 1 +
> ipc/compat.c | 1 +
> ipc/sem.c | 10 ++++++++--
> security/selinux/hooks.c | 1 +
> security/smack/smack_lsm.c | 1 +
> 5 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/include/uapi/linux/sem.h b/include/uapi/linux/sem.h
> index 541fce0..b6ae374 100644
> --- a/include/uapi/linux/sem.h
> +++ b/include/uapi/linux/sem.h
> @@ -18,6 +18,7 @@
> /* ipcs ctl cmds */
> #define SEM_STAT 18
> #define SEM_INFO 19
> +#define SEM_SET 20
>
> /* Obsolete, used only for backwards compatibility and libc5 compiles */
> struct semid_ds {
> diff --git a/ipc/compat.c b/ipc/compat.c
> index 9c70f9a..84d8efd 100644
> --- a/ipc/compat.c
> +++ b/ipc/compat.c
> @@ -290,6 +290,7 @@ static long do_compat_semctl(int first, int second, int third, u32 pad)
> break;
>
> case IPC_SET:
> + case SEM_SET:
> if (version == IPC_64) {
> err = get_compat_semid64_ds(&s64, compat_ptr(pad));
> } else {
> diff --git a/ipc/sem.c b/ipc/sem.c
> index 10e9085..3eac885 100644
> --- a/ipc/sem.c
> +++ b/ipc/sem.c
> @@ -1085,12 +1085,13 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
> struct semid64_ds semid64;
> struct kern_ipc_perm *ipcp;
>
> - if(cmd == IPC_SET) {
> + if (cmd == IPC_SET || cmd == SEM_SET) {
> if (copy_semid_from_user(&semid64, arg.buf, version))
> return -EFAULT;
> }
>
> - ipcp = ipcctl_pre_down(ns, &sem_ids(ns), semid, cmd,
> + ipcp = ipcctl_pre_down(ns, &sem_ids(ns), semid,
> + (cmd != SEM_SET) ? cmd : IPC_SET,
> &semid64.sem_perm, 0);
> if (IS_ERR(ipcp))
> return PTR_ERR(ipcp);
> @@ -1105,6 +1106,10 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
> case IPC_RMID:
> freeary(ns, ipcp);
> goto out_up;
> + case SEM_SET:
> + err = ipc_update_key(&sem_ids(ns), &semid64.sem_perm, ipcp);
> + if (err)
> + break;
> case IPC_SET:
> err = ipc_update_perm(&semid64.sem_perm, ipcp);
> if (err)
> @@ -1152,6 +1157,7 @@ SYSCALL_DEFINE(semctl)(int semid, int semnum, int cmd, union semun arg)
> return err;
> case IPC_RMID:
> case IPC_SET:
> + case SEM_SET:
> err = semctl_down(ns, semid, cmd, version, arg);
> return err;
> default:
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 78b77ac..02b037d 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -5133,6 +5133,7 @@ static int selinux_sem_semctl(struct sem_array *sma, int cmd)
> perms = SEM__DESTROY;
> break;
> case IPC_SET:
> + case SEM_SET:
> perms = SEM__SETATTR;
> break;
> case IPC_STAT:
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index d51a8da..b4135ed 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -2253,6 +2253,7 @@ static int smack_sem_semctl(struct sem_array *sma, int cmd)
> case SETALL:
> case IPC_RMID:
> case IPC_SET:
> + case SEM_SET:
> may = MAY_READWRITE;
> break;
> case IPC_INFO:
>
> --
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