This is a note to let you know that I've just added the patch titled ipc: always handle a new value of auto_msgmni to the 3.17-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipc-always-handle-a-new-value-of-auto_msgmni.patch and it can be found in the queue-3.17 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 1195d94e006b23c6292e78857e154872e33b6d7e Mon Sep 17 00:00:00 2001 From: Andrey Vagin <avagin@xxxxxxxxxx> Date: Mon, 13 Oct 2014 15:54:10 -0700 Subject: ipc: always handle a new value of auto_msgmni From: Andrey Vagin <avagin@xxxxxxxxxx> 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@xxxxxxxxxx> Cc: Mathias Krause <minipli@xxxxxxxxxxxxxx> Cc: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx> Cc: Joe Perches <joe@xxxxxxxxxxx> Cc: Davidlohr Bueso <davidlohr@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- ipc/ipc_sysctl.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/ipc/ipc_sysctl.c +++ b/ipc/ipc_sysctl.c @@ -123,7 +123,6 @@ static int proc_ipcauto_dointvec_minmax( 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( 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. Patches currently in stable-queue which might be from avagin@xxxxxxxxxx are queue-3.17/ipc-always-handle-a-new-value-of-auto_msgmni.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html