The patch titled
sysctl: simplify sysctl_uts_string
has been added to the -mm tree. Its filename is
sysctl-simplify-sysctl_uts_string.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: sysctl: simplify sysctl_uts_string
From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
The binary interface to the namespace sysctls was never implemented resulting
in some really weird things if you attempted to use sys_sysctl to read your
hostname for example.
This patch series simples the code a little and implements the binary sysctl
interface.
In testing this patch series I discovered that our 32bit compatibility for the
binary sysctl interface is imperfect. In particular KERN_SHMMAX and
KERN_SMMALL are size_t sized quantities and are returned as 8 bytes on to
32bit binaries using a x86_64 kernel. However this has existing for a long
time so it is not a new regression with the namespace work.
Gads the whole sysctl thing needs work before it stops being easy to shoot
yourself in the foot.
Looking forward a little bit we need a better way to handle sysctls and
namespaces as our current technique will not work for the network namespace.
I think something based on the current overlapping sysctl trees will work but
the proc side needs to be redone before we can use it.
This patch:
Introduce get_uts() and put_uts() (used later) and remove most of the special
cases for when UTS namespace is compiled in.
Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
kernel/sysctl.c | 128 +++++++++-------------------------------------
1 files changed, 26 insertions(+), 102 deletions(-)
diff -puN kernel/sysctl.c~sysctl-simplify-sysctl_uts_string kernel/sysctl.c
--- a/kernel/sysctl.c~sysctl-simplify-sysctl_uts_string
+++ a/kernel/sysctl.c
@@ -163,6 +163,28 @@ extern ctl_table inotify_table[];
int sysctl_legacy_va_layout;
#endif
+static void *get_uts(ctl_table *table, int write)
+{
+ char *which = table->data;
+#ifdef CONFIG_UTS_NS
+ struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
+ which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
+#endif
+ if (!write)
+ down_read(&uts_sem);
+ else
+ down_write(&uts_sem);
+ return which;
+}
+
+static void put_uts(ctl_table *table, int write, void *which)
+{
+ if (!write)
+ up_read(&uts_sem);
+ else
+ up_write(&uts_sem);
+}
+
/* /proc declarations: */
#ifdef CONFIG_PROC_SYSCTL
@@ -229,7 +251,6 @@ static ctl_table root_table[] = {
};
static ctl_table kern_table[] = {
-#ifndef CONFIG_UTS_NS
{
.ctl_name = KERN_OSTYPE,
.procname = "ostype",
@@ -275,54 +296,6 @@ static ctl_table kern_table[] = {
.proc_handler = &proc_do_uts_string,
.strategy = &sysctl_string,
},
-#else /* !CONFIG_UTS_NS */
- {
- .ctl_name = KERN_OSTYPE,
- .procname = "ostype",
- .data = NULL,
- /* could maybe use __NEW_UTS_LEN here? */
- .maxlen = FIELD_SIZEOF(struct new_utsname, sysname),
- .mode = 0444,
- .proc_handler = &proc_do_uts_string,
- .strategy = &sysctl_string,
- },
- {
- .ctl_name = KERN_OSRELEASE,
- .procname = "osrelease",
- .data = NULL,
- .maxlen = FIELD_SIZEOF(struct new_utsname, release),
- .mode = 0444,
- .proc_handler = &proc_do_uts_string,
- .strategy = &sysctl_string,
- },
- {
- .ctl_name = KERN_VERSION,
- .procname = "version",
- .data = NULL,
- .maxlen = FIELD_SIZEOF(struct new_utsname, version),
- .mode = 0444,
- .proc_handler = &proc_do_uts_string,
- .strategy = &sysctl_string,
- },
- {
- .ctl_name = KERN_NODENAME,
- .procname = "hostname",
- .data = NULL,
- .maxlen = FIELD_SIZEOF(struct new_utsname, nodename),
- .mode = 0644,
- .proc_handler = &proc_do_uts_string,
- .strategy = &sysctl_string,
- },
- {
- .ctl_name = KERN_DOMAINNAME,
- .procname = "domainname",
- .data = NULL,
- .maxlen = FIELD_SIZEOF(struct new_utsname, domainname),
- .mode = 0644,
- .proc_handler = &proc_do_uts_string,
- .strategy = &sysctl_string,
- },
-#endif /* !CONFIG_UTS_NS */
{
.ctl_name = KERN_PANIC,
.procname = "panic",
@@ -1755,66 +1728,17 @@ int proc_dostring(ctl_table *table, int
* Special case of dostring for the UTS structure. This has locks
* to observe. Should this be in kernel/sys.c ????
*/
-
-#ifndef CONFIG_UTS_NS
-static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
- void __user *buffer, size_t *lenp, loff_t *ppos)
-{
- int r;
- if (!write) {
- down_read(&uts_sem);
- r=proc_dostring(table,0,filp,buffer,lenp, ppos);
- up_read(&uts_sem);
- } else {
- down_write(&uts_sem);
- r=proc_dostring(table,1,filp,buffer,lenp, ppos);
- up_write(&uts_sem);
- }
- return r;
-}
-#else /* !CONFIG_UTS_NS */
static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
int r;
- struct uts_namespace* uts_ns = current->nsproxy->uts_ns;
- char* which;
-
- switch (table->ctl_name) {
- case KERN_OSTYPE:
- which = uts_ns->name.sysname;
- break;
- case KERN_NODENAME:
- which = uts_ns->name.nodename;
- break;
- case KERN_OSRELEASE:
- which = uts_ns->name.release;
- break;
- case KERN_VERSION:
- which = uts_ns->name.version;
- break;
- case KERN_DOMAINNAME:
- which = uts_ns->name.domainname;
- break;
- default:
- r = -EINVAL;
- goto out;
- }
-
- if (!write) {
- down_read(&uts_sem);
- r=_proc_do_string(which,table->maxlen,0,filp,buffer,lenp, ppos);
- up_read(&uts_sem);
- } else {
- down_write(&uts_sem);
- r=_proc_do_string(which,table->maxlen,1,filp,buffer,lenp, ppos);
- up_write(&uts_sem);
- }
- out:
+ void *which;
+ which = get_uts(table, write);
+ r = _proc_do_string(which, table->maxlen,write,filp,buffer,lenp, ppos);
+ put_uts(table, write, which);
return r;
}
-#endif /* !CONFIG_UTS_NS */
static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
int *valp,
_
Patches currently in -mm which might be from ebiederm@xxxxxxxxxxxx are
origin.patch
x86-64-calling-clear_bss-before-set_intr_gate-with-early_idt_handler.patch
x86-64-change-the-size-for-interrupt-array-to-nr_vectors.patch
make-fs-proc-basecproc_pid_instantiate-static.patch
add-process_session-helper-routine.patch
rename-struct-namespace-to-struct-mnt_namespace.patch
add-an-identifier-to-nsproxy.patch
rename-struct-pspace-to-struct-pid_namespace.patch
add-pid_namespace-to-nsproxy.patch
use-current-nsproxy-pid_ns.patch
add-child-reaper-to-pid_namespace.patch
sysctl-simplify-sysctl_uts_string.patch
sysctl-implement-sysctl_uts_string.patch
sysctl-simplify-ipc-ns-specific-sysctls.patch
sysctl-fix-sys_sysctl-interface-of-ipc-sysctls.patch
updated-i386-cleanup-apic-code.patch
updated-i386-rework-local-apic-calibration.patch
updated-dynticks-fix-nmi-watchdog.patch
clockevents-core-check-for-clock-event-device-handler-being-non-null-before-calling-it.patch
pidhash-temporary-debug-checks.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
