X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=blobdiff_plain;f=ipc%2Fipc_sysctl.c;h=56410faa4550ee65d521aad623e0f52d5a522368;hp=79e24e878c1eae6d2dc1247f72dec8de71ce2108;hb=4434ade8c9334a3ab975d8993de456f06841899e;hpb=a08b4be74ca4199838cbb03d90906a0fd70d3b3c diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c index 79e24e8..56410fa 100644 --- a/ipc/ipc_sysctl.c +++ b/ipc/ipc_sysctl.c @@ -14,6 +14,9 @@ #include #include #include +#include +#include +#include "util.h" static void *get_ipc(ctl_table *table) { @@ -23,146 +26,176 @@ static void *get_ipc(ctl_table *table) return which; } -#ifdef CONFIG_PROC_FS -static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp, +#ifdef CONFIG_PROC_SYSCTL +static int proc_ipc_dointvec(ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table ipc_table; memcpy(&ipc_table, table, sizeof(ipc_table)); ipc_table.data = get_ipc(table); - return proc_dointvec(&ipc_table, write, filp, buffer, lenp, ppos); + return proc_dointvec(&ipc_table, write, buffer, lenp, ppos); +} + +static int proc_ipc_callback_dointvec(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 rc; + + memcpy(&ipc_table, table, sizeof(ipc_table)); + ipc_table.data = get_ipc(table); + + rc = proc_dointvec(&ipc_table, write, buffer, lenp, ppos); + + if (write && !rc && lenp_bef == *lenp) + /* + * Tunable has successfully been changed by hand. Disable its + * automatic adjustment. This simply requires unregistering + * the notifiers that trigger recalculation. + */ + unregister_ipcns_notifier(current->nsproxy->ipc_ns); + + return rc; } static int proc_ipc_doulongvec_minmax(ctl_table *table, int write, - struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos) + void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table ipc_table; memcpy(&ipc_table, table, sizeof(ipc_table)); ipc_table.data = get_ipc(table); - return proc_doulongvec_minmax(&ipc_table, write, filp, buffer, + return proc_doulongvec_minmax(&ipc_table, write, buffer, lenp, ppos); } -#else -#define proc_ipc_doulongvec_minmax NULL -#define proc_ipc_dointvec NULL -#endif - -#ifdef CONFIG_SYSCTL_SYSCALL -/* The generic sysctl ipc data routine. */ -static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen, - void __user *oldval, size_t __user *oldlenp, - void __user *newval, size_t newlen) +/* + * Routine that is called when the file "auto_msgmni" has successfully been + * written. + * Two values are allowed: + * 0: unregister msgmni's callback routine from the ipc namespace notifier + * chain. This means that msgmni won't be recomputed anymore upon memory + * add/remove or ipc namespace creation/removal. + * 1: register back the callback routine. + */ +static void ipc_auto_callback(int val) { - size_t len; - void *data; - - /* Get out of I don't have a variable */ - if (!table->data || !table->maxlen) - return -ENOTDIR; - - data = get_ipc(table); - if (!data) - return -ENOTDIR; - - if (oldval && oldlenp) { - if (get_user(len, oldlenp)) - return -EFAULT; - if (len) { - if (len > table->maxlen) - len = table->maxlen; - if (copy_to_user(oldval, data, len)) - return -EFAULT; - if (put_user(len, oldlenp)) - return -EFAULT; - } + if (!val) + unregister_ipcns_notifier(current->nsproxy->ipc_ns); + else { + /* + * Re-enable automatic recomputing only if not already + * enabled. + */ + recompute_msgmni(current->nsproxy->ipc_ns); + cond_register_ipcns_notifier(current->nsproxy->ipc_ns); } +} - if (newval && newlen) { - if (newlen > table->maxlen) - newlen = table->maxlen; +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; - if (copy_from_user(data, newval, newlen)) - return -EFAULT; + memcpy(&ipc_table, table, sizeof(ipc_table)); + ipc_table.data = get_ipc(table); + oldval = *((int *)(ipc_table.data)); + + rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos); + + if (write && !rc && lenp_bef == *lenp) { + int newval = *((int *)(ipc_table.data)); + /* + * The file "auto_msgmni" has correctly been set. + * React by (un)registering the corresponding tunable, if the + * value has changed. + */ + if (newval != oldval) + ipc_auto_callback(newval); } - return 1; + + return rc; } + #else -#define sysctl_ipc_data NULL +#define proc_ipc_doulongvec_minmax NULL +#define proc_ipc_dointvec NULL +#define proc_ipc_callback_dointvec NULL +#define proc_ipcauto_dointvec_minmax NULL #endif +static int zero; +static int one = 1; + static struct ctl_table ipc_kern_table[] = { { - .ctl_name = KERN_SHMMAX, .procname = "shmmax", .data = &init_ipc_ns.shm_ctlmax, .maxlen = sizeof (init_ipc_ns.shm_ctlmax), .mode = 0644, .proc_handler = proc_ipc_doulongvec_minmax, - .strategy = sysctl_ipc_data, }, { - .ctl_name = KERN_SHMALL, .procname = "shmall", .data = &init_ipc_ns.shm_ctlall, .maxlen = sizeof (init_ipc_ns.shm_ctlall), .mode = 0644, .proc_handler = proc_ipc_doulongvec_minmax, - .strategy = sysctl_ipc_data, }, { - .ctl_name = KERN_SHMMNI, .procname = "shmmni", .data = &init_ipc_ns.shm_ctlmni, .maxlen = sizeof (init_ipc_ns.shm_ctlmni), .mode = 0644, .proc_handler = proc_ipc_dointvec, - .strategy = sysctl_ipc_data, }, { - .ctl_name = KERN_MSGMAX, .procname = "msgmax", .data = &init_ipc_ns.msg_ctlmax, .maxlen = sizeof (init_ipc_ns.msg_ctlmax), .mode = 0644, .proc_handler = proc_ipc_dointvec, - .strategy = sysctl_ipc_data, }, { - .ctl_name = KERN_MSGMNI, .procname = "msgmni", .data = &init_ipc_ns.msg_ctlmni, .maxlen = sizeof (init_ipc_ns.msg_ctlmni), .mode = 0644, - .proc_handler = proc_ipc_dointvec, - .strategy = sysctl_ipc_data, + .proc_handler = proc_ipc_callback_dointvec, }, { - .ctl_name = KERN_MSGMNB, .procname = "msgmnb", .data = &init_ipc_ns.msg_ctlmnb, .maxlen = sizeof (init_ipc_ns.msg_ctlmnb), .mode = 0644, .proc_handler = proc_ipc_dointvec, - .strategy = sysctl_ipc_data, }, { - .ctl_name = KERN_SEM, .procname = "sem", .data = &init_ipc_ns.sem_ctls, .maxlen = 4*sizeof (int), .mode = 0644, .proc_handler = proc_ipc_dointvec, - .strategy = sysctl_ipc_data, + }, + { + .procname = "auto_msgmni", + .data = &init_ipc_ns.auto_msgmni, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_ipcauto_dointvec_minmax, + .extra1 = &zero, + .extra2 = &one, }, {} }; static struct ctl_table ipc_root_table[] = { { - .ctl_name = CTL_KERN, .procname = "kernel", .mode = 0555, .child = ipc_kern_table,