lkml.org 
[lkml]   [2006]   [Nov]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3/4] sysctl: Simplify ipc ns specific sysctls
Date
This patch refactors the ipc sysctl support so that it is
simpler, more readable, and prepares for fixing the bug
with the wrong values being returned in the sys_sysctl interface.

The function proc_do_ipc_string was misnamed as it never handled
strings. It's magic of when to work with strings and when to work
with longs belonged in the sysctl table. I couldn't tell if the
code would work if you disabled the ipc namespace but it certainly
looked like it would have problems.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
kernel/sysctl.c | 106 +++++++++++++++++++++++++------------------------------
1 files changed, 49 insertions(+), 57 deletions(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 63db5a5..638aa14 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -91,7 +91,9 @@ #ifdef CONFIG_CHR_DEV_SG
extern int sg_big_buff;
#endif
#ifdef CONFIG_SYSVIPC
-static int proc_do_ipc_string(ctl_table *table, int write, struct file *filp,
+static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
+ void __user *buffer, size_t *lenp, loff_t *ppos);
+static int proc_ipc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos);
#endif

@@ -188,6 +190,18 @@ static void put_uts(ctl_table *table, in
up_write(&uts_sem);
}

+#ifdef CONFIG_SYSVIPC
+static void *get_ipc(ctl_table *table, int write)
+{
+ char *which = table->data;
+ struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
+ which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
+ return which;
+}
+#else
+#define get_ipc(T,W) ((T)->data)
+#endif
+
/* /proc declarations: */

#ifdef CONFIG_PROC_SYSCTL
@@ -457,58 +471,58 @@ #ifdef CONFIG_SYSVIPC
{
.ctl_name = KERN_SHMMAX,
.procname = "shmmax",
- .data = NULL,
- .maxlen = sizeof (size_t),
+ .data = &init_ipc_ns.shm_ctlmax,
+ .maxlen = sizeof (init_ipc_ns.shm_ctlmax),
.mode = 0644,
- .proc_handler = &proc_do_ipc_string,
+ .proc_handler = &proc_ipc_doulongvec_minmax,
},
{
.ctl_name = KERN_SHMALL,
.procname = "shmall",
- .data = NULL,
- .maxlen = sizeof (size_t),
+ .data = &init_ipc_ns.shm_ctlall,
+ .maxlen = sizeof (init_ipc_ns.shm_ctlall),
.mode = 0644,
- .proc_handler = &proc_do_ipc_string,
+ .proc_handler = &proc_ipc_doulongvec_minmax,
},
{
.ctl_name = KERN_SHMMNI,
.procname = "shmmni",
- .data = NULL,
- .maxlen = sizeof (int),
+ .data = &init_ipc_ns.shm_ctlmni,
+ .maxlen = sizeof (init_ipc_ns.shm_ctlmni),
.mode = 0644,
- .proc_handler = &proc_do_ipc_string,
+ .proc_handler = &proc_ipc_dointvec,
},
{
.ctl_name = KERN_MSGMAX,
.procname = "msgmax",
- .data = NULL,
- .maxlen = sizeof (int),
+ .data = &init_ipc_ns.msg_ctlmax,
+ .maxlen = sizeof (init_ipc_ns.msg_ctlmax),
.mode = 0644,
- .proc_handler = &proc_do_ipc_string,
+ .proc_handler = &proc_ipc_dointvec,
},
{
.ctl_name = KERN_MSGMNI,
.procname = "msgmni",
- .data = NULL,
- .maxlen = sizeof (int),
+ .data = &init_ipc_ns.msg_ctlmni,
+ .maxlen = sizeof (init_ipc_ns.msg_ctlmni),
.mode = 0644,
- .proc_handler = &proc_do_ipc_string,
+ .proc_handler = &proc_ipc_dointvec,
},
{
.ctl_name = KERN_MSGMNB,
.procname = "msgmnb",
- .data = NULL,
- .maxlen = sizeof (int),
+ .data = &init_ipc_ns.msg_ctlmnb,
+ .maxlen = sizeof (init_ipc_ns.msg_ctlmnb),
.mode = 0644,
- .proc_handler = &proc_do_ipc_string,
+ .proc_handler = &proc_ipc_dointvec,
},
{
.ctl_name = KERN_SEM,
.procname = "sem",
- .data = NULL,
+ .data = &init_ipc_ns.sem_ctls,
.maxlen = 4*sizeof (int),
.mode = 0644,
- .proc_handler = &proc_do_ipc_string,
+ .proc_handler = &proc_ipc_dointvec,
},
#endif
#ifdef CONFIG_MAGIC_SYSRQ
@@ -2321,46 +2335,24 @@ int proc_dointvec_ms_jiffies(ctl_table *
}

#ifdef CONFIG_SYSVIPC
-static int proc_do_ipc_string(ctl_table *table, int write, struct file *filp,
- void __user *buffer, size_t *lenp, loff_t *ppos)
+static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
{
- void *data;
- struct ipc_namespace *ns;
-
- ns = current->nsproxy->ipc_ns;
-
- switch (table->ctl_name) {
- case KERN_SHMMAX:
- data = &ns->shm_ctlmax;
- goto proc_minmax;
- case KERN_SHMALL:
- data = &ns->shm_ctlall;
- goto proc_minmax;
- case KERN_SHMMNI:
- data = &ns->shm_ctlmni;
- break;
- case KERN_MSGMAX:
- data = &ns->msg_ctlmax;
- break;
- case KERN_MSGMNI:
- data = &ns->msg_ctlmni;
- break;
- case KERN_MSGMNB:
- data = &ns->msg_ctlmnb;
- break;
- case KERN_SEM:
- data = &ns->sem_ctls;
- break;
- default:
- return -EINVAL;
- }
-
- return __do_proc_dointvec(data, table, write, filp, buffer,
+ void *which;
+ which = get_ipc(table, write);
+ return __do_proc_dointvec(which, table, write, filp, buffer,
lenp, ppos, NULL, NULL);
-proc_minmax:
- return __do_proc_doulongvec_minmax(data, table, write, filp, buffer,
+}
+
+static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
+ struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ void *which;
+ which = get_ipc(table, write);
+ return __do_proc_doulongvec_minmax(which, table, write, filp, buffer,
lenp, ppos, 1l, 1l);
}
+
#endif

static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
--
1.4.2.rc3.g7e18e-dirty
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-11-27 06:11    [W:0.098 / U:5.392 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site