summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAndrey Vagin <avagin@openvz.org>2014-10-13 15:54:10 -0700
committerJiri Slaby <jslaby@suse.cz>2014-11-19 18:38:25 +0100
commit04e7556e9c84532bbdbe5663b7b25eb8ca15c14e (patch)
tree1e051cba79c5a260242776e733eb739afa0eb206
parent0f207b54545a7535e02e7ca11931655396e15846 (diff)
downloadlwn-04e7556e9c84532bbdbe5663b7b25eb8ca15c14e.tar.gz
lwn-04e7556e9c84532bbdbe5663b7b25eb8ca15c14e.zip
ipc: always handle a new value of auto_msgmni
commit 1195d94e006b23c6292e78857e154872e33b6d7e upstream. proc_dointvec_minmax() returns zero if a new value has been set. So we don't need to check all charecters have been handled. Below you can find two examples. In the new value has not been handled properly. $ strace ./a.out open("/proc/sys/kernel/auto_msgmni", O_WRONLY) = 3 write(3, "0\n\0", 3) = 2 close(3) = 0 exit_group(0) $ cat /sys/kernel/debug/tracing/trace $strace ./a.out open("/proc/sys/kernel/auto_msgmni", O_WRONLY) = 3 write(3, "0\n", 2) = 2 close(3) = 0 $ cat /sys/kernel/debug/tracing/trace a.out-697 [000] .... 3280.998235: unregister_ipcns_notifier <-proc_ipcauto_dointvec_minmax Fixes: 9eefe520c814 ("ipc: do not use a negative value to re-enable msgmni automatic recomputin") Signed-off-by: Andrey Vagin <avagin@openvz.org> Cc: Mathias Krause <minipli@googlemail.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Joe Perches <joe@perches.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
-rw-r--r--ipc/ipc_sysctl.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
index b0e99deb6d05..a0f0ab2ac2a8 100644
--- a/ipc/ipc_sysctl.c
+++ b/ipc/ipc_sysctl.c
@@ -123,7 +123,6 @@ static int proc_ipcauto_dointvec_minmax(ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
struct ctl_table ipc_table;
- size_t lenp_bef = *lenp;
int oldval;
int rc;
@@ -133,7 +132,7 @@ static int proc_ipcauto_dointvec_minmax(ctl_table *table, int write,
rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
- if (write && !rc && lenp_bef == *lenp) {
+ if (write && !rc) {
int newval = *((int *)(ipc_table.data));
/*
* The file "auto_msgmni" has correctly been set.