From: Doug Ledford Date: Fri, 2 Dec 2011 03:09:12 +0000 (+1100) Subject: ipc/mqueue: cleanup definition names and locations X-Git-Tag: next-20111205~1^2~191 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=c595a648cabbd66d6227238a360fa0d4331904f1;p=karo-tx-linux.git ipc/mqueue: cleanup definition names and locations We had a customer come up with a problem while trying to upgrade from our 2.6.18 kernel to our 2.6.32 kernel. In diagnosing their problem, it was determined that when commit b231cca4 ("message queues: increase range limits") changed the msg size max from INT_MAX to 8192*128, that's what broke their setup. While fixing this problem, testing showed that if you increase the max values of a msg queue, then attempt to create one without an attr struct passed in to the open call, it could fail because it sets the queue size to the max of both the msg size and queue size. If these are large enough, they over run the default RLIMIT_MSGQUEUE. This change was also introduced in the b231cca4 ("message queues: increase range limits") commit. We then found that the msg queue limits were not all being enforced on CAP_SYS_RESOURCE apps. Finally, we found that commit 9cf18e1d ("ipc: HARD_MSGMAX should be higher not lower on 64bit") fiddled with HARD_MSGMAX without realizing that the reason it was set to what it was, was to avoid trying to kmalloc a chunk larger than 128K. So this series of patches cleans up the various defines, takes us back to having a larger HARD_MSGSIZEMAX, goes back to using a separate define for the case where a user doesn't pass in an attr struct in case the maxes have been raised too large for RLIMIT_MSGQUEUE, enforces the maximums on CAP_SYS_RESOURCE apps, uses vmalloc instead of kmalloc when the msg pointer array is too large, and documents all of this so it shouldn't happen again. This patch: The various defines for minimums and maximums of the sysctl controllable mqueue values are scattered amongst different files and named inconsistently. Move them all into ipc_namespace.h and make them have consistent names. Additionally, make the number of queues per namespace also have a minimum and maximum and use the same sysctl function as the other two settable variables. Signed-off-by: Doug Ledford Cc: Amerigo Wang Cc: Serge E. Hallyn Cc: Joe Korty Cc: Manfred Spraul Cc: Cc: Signed-off-by: Andrew Morton --- diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h index 8a297a5e794c..1372b566e1e1 100644 --- a/include/linux/ipc_namespace.h +++ b/include/linux/ipc_namespace.h @@ -91,10 +91,15 @@ static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {} #ifdef CONFIG_POSIX_MQUEUE extern int mq_init_ns(struct ipc_namespace *ns); /* default values */ +#define MIN_QUEUESMAX 1 #define DFLT_QUEUESMAX 256 /* max number of message queues */ +#define HARD_QUEUESMAX 1024 +#define MIN_MSGMAX 1 #define DFLT_MSGMAX 10 /* max number of messages in each queue */ #define HARD_MSGMAX (32768*sizeof(void *)/4) +#define MIN_MSGSIZEMAX 128 #define DFLT_MSGSIZEMAX 8192 /* max message size */ +#define HARD_MSGSIZEMAX (8192*128) #else static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } #endif diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c index 0c09366b96f3..e22336a09b4a 100644 --- a/ipc/mq_sysctl.c +++ b/ipc/mq_sysctl.c @@ -13,15 +13,6 @@ #include #include -/* - * Define the ranges various user-specified maximum values can - * be set to. - */ -#define MIN_MSGMAX 1 /* min value for msg_max */ -#define MAX_MSGMAX HARD_MSGMAX /* max value for msg_max */ -#define MIN_MSGSIZEMAX 128 /* min value for msgsize_max */ -#define MAX_MSGSIZEMAX (8192*128) /* max value for msgsize_max */ - #ifdef CONFIG_PROC_SYSCTL static void *get_mq(ctl_table *table) { @@ -31,16 +22,6 @@ static void *get_mq(ctl_table *table) return which; } -static int proc_mq_dointvec(ctl_table *table, int write, - void __user *buffer, size_t *lenp, loff_t *ppos) -{ - struct ctl_table mq_table; - memcpy(&mq_table, table, sizeof(mq_table)); - mq_table.data = get_mq(table); - - return proc_dointvec(&mq_table, write, buffer, lenp, ppos); -} - static int proc_mq_dointvec_minmax(ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { @@ -52,15 +33,17 @@ static int proc_mq_dointvec_minmax(ctl_table *table, int write, lenp, ppos); } #else -#define proc_mq_dointvec NULL #define proc_mq_dointvec_minmax NULL #endif +static int msg_queues_limit_min = MIN_QUEUESMAX; +static int msg_queues_limit_max = HARD_QUEUESMAX; + static int msg_max_limit_min = MIN_MSGMAX; -static int msg_max_limit_max = MAX_MSGMAX; +static int msg_max_limit_max = HARD_MSGMAX; static int msg_maxsize_limit_min = MIN_MSGSIZEMAX; -static int msg_maxsize_limit_max = MAX_MSGSIZEMAX; +static int msg_maxsize_limit_max = HARD_MSGSIZEMAX; static ctl_table mq_sysctls[] = { { @@ -68,7 +51,9 @@ static ctl_table mq_sysctls[] = { .data = &init_ipc_ns.mq_queues_max, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_mq_dointvec, + .proc_handler = proc_mq_dointvec_minmax, + .extra1 = &msg_queues_limit_min, + .extra2 = &msg_queues_limit_max, }, { .procname = "msg_max",