diff options
author | Ingo Molnar <mingo@kernel.org> | 2012-04-14 13:18:27 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2012-04-14 13:19:04 +0200 |
commit | 6ac1ef482d7ae0c690f1640bf6eb818ff9a2d91e (patch) | |
tree | 021cc9f6b477146fcebe6f3be4752abfa2ba18a9 /kernel/sysctl.c | |
parent | 682968e0c425c60f0dde37977e5beb2b12ddc4cc (diff) | |
parent | a385ec4f11bdcf81af094c03e2444ee9b7fad2e5 (diff) |
Merge branch 'perf/core' into perf/uprobes
Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sysctl.c')
-rw-r--r-- | kernel/sysctl.c | 522 |
1 files changed, 14 insertions, 508 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index f487f257e05..4ab11879aeb 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -23,6 +23,7 @@ #include <linux/swap.h> #include <linux/slab.h> #include <linux/sysctl.h> +#include <linux/bitmap.h> #include <linux/signal.h> #include <linux/printk.h> #include <linux/proc_fs.h> @@ -58,6 +59,7 @@ #include <linux/oom.h> #include <linux/kmod.h> #include <linux/capability.h> +#include <linux/binfmts.h> #include <asm/uaccess.h> #include <asm/processor.h> @@ -67,6 +69,9 @@ #include <asm/stacktrace.h> #include <asm/io.h> #endif +#ifdef CONFIG_SPARC +#include <asm/setup.h> +#endif #ifdef CONFIG_BSD_PROCESS_ACCT #include <linux/acct.h> #endif @@ -141,7 +146,6 @@ static const int cap_last_cap = CAP_LAST_CAP; #include <linux/inotify.h> #endif #ifdef CONFIG_SPARC -#include <asm/system.h> #endif #ifdef CONFIG_SPARC64 @@ -166,7 +170,7 @@ static int proc_taint(struct ctl_table *table, int write, #endif #ifdef CONFIG_PRINTK -static int proc_dmesg_restrict(struct ctl_table *table, int write, +static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); #endif @@ -192,20 +196,6 @@ static int sysrq_sysctl_handler(ctl_table *table, int write, #endif -static struct ctl_table root_table[]; -static struct ctl_table_root sysctl_table_root; -static struct ctl_table_header root_table_header = { - {{.count = 1, - .ctl_table = root_table, - .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}}, - .root = &sysctl_table_root, - .set = &sysctl_table_root.default_set, -}; -static struct ctl_table_root sysctl_table_root = { - .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list), - .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry), -}; - static struct ctl_table kern_table[]; static struct ctl_table vm_table[]; static struct ctl_table fs_table[]; @@ -222,7 +212,7 @@ int sysctl_legacy_va_layout; /* The default sysctl tables: */ -static struct ctl_table root_table[] = { +static struct ctl_table sysctl_base_table[] = { { .procname = "kernel", .mode = 0555, @@ -713,7 +703,7 @@ static struct ctl_table kern_table[] = { .data = &dmesg_restrict, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec_minmax, + .proc_handler = proc_dointvec_minmax_sysadmin, .extra1 = &zero, .extra2 = &one, }, @@ -722,7 +712,7 @@ static struct ctl_table kern_table[] = { .data = &kptr_restrict, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dmesg_restrict, + .proc_handler = proc_dointvec_minmax_sysadmin, .extra1 = &zero, .extra2 = &two, }, @@ -1559,490 +1549,12 @@ static struct ctl_table dev_table[] = { { } }; -static DEFINE_SPINLOCK(sysctl_lock); - -/* called under sysctl_lock */ -static int use_table(struct ctl_table_header *p) -{ - if (unlikely(p->unregistering)) - return 0; - p->used++; - return 1; -} - -/* called under sysctl_lock */ -static void unuse_table(struct ctl_table_header *p) -{ - if (!--p->used) - if (unlikely(p->unregistering)) - complete(p->unregistering); -} - -/* called under sysctl_lock, will reacquire if has to wait */ -static void start_unregistering(struct ctl_table_header *p) -{ - /* - * if p->used is 0, nobody will ever touch that entry again; - * we'll eliminate all paths to it before dropping sysctl_lock - */ - if (unlikely(p->used)) { - struct completion wait; - init_completion(&wait); - p->unregistering = &wait; - spin_unlock(&sysctl_lock); - wait_for_completion(&wait); - spin_lock(&sysctl_lock); - } else { - /* anything non-NULL; we'll never dereference it */ - p->unregistering = ERR_PTR(-EINVAL); - } - /* - * do not remove from the list until nobody holds it; walking the - * list in do_sysctl() relies on that. - */ - list_del_init(&p->ctl_entry); -} - -void sysctl_head_get(struct ctl_table_header *head) -{ - spin_lock(&sysctl_lock); - head->count++; - spin_unlock(&sysctl_lock); -} - -void sysctl_head_put(struct ctl_table_header *head) -{ - spin_lock(&sysctl_lock); - if (!--head->count) - kfree_rcu(head, rcu); - spin_unlock(&sysctl_lock); -} - -struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) -{ - if (!head) - BUG(); - spin_lock(&sysctl_lock); - if (!use_table(head)) - head = ERR_PTR(-ENOENT); - spin_unlock(&sysctl_lock); - return head; -} - -void sysctl_head_finish(struct ctl_table_header *head) -{ - if (!head) - return; - spin_lock(&sysctl_lock); - unuse_table(head); - spin_unlock(&sysctl_lock); -} - -static struct ctl_table_set * -lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces) -{ - struct ctl_table_set *set = &root->default_set; - if (root->lookup) - set = root->lookup(root, namespaces); - return set; -} - -static struct list_head * -lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces) -{ - struct ctl_table_set *set = lookup_header_set(root, namespaces); - return &set->list; -} - -struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces, - struct ctl_table_header *prev) +int __init sysctl_init(void) { - struct ctl_table_root *root; - struct list_head *header_list; - struct ctl_table_header *head; - struct list_head *tmp; - - spin_lock(&sysctl_lock); - if (prev) { - head = prev; - tmp = &prev->ctl_entry; - unuse_table(prev); - goto next; - } - tmp = &root_table_header.ctl_entry; - for (;;) { - head = list_entry(tmp, struct ctl_table_header, ctl_entry); - - if (!use_table(head)) - goto next; - spin_unlock(&sysctl_lock); - return head; - next: - root = head->root; - tmp = tmp->next; - header_list = lookup_header_list(root, namespaces); - if (tmp != header_list) - continue; - - do { - root = list_entry(root->root_list.next, - struct ctl_table_root, root_list); - if (root == &sysctl_table_root) - goto out; - header_list = lookup_header_list(root, namespaces); - } while (list_empty(header_list)); - tmp = header_list->next; - } -out: - spin_unlock(&sysctl_lock); - return NULL; -} - -struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev) -{ - return __sysctl_head_next(current->nsproxy, prev); -} - -void register_sysctl_root(struct ctl_table_root *root) -{ - spin_lock(&sysctl_lock); - list_add_tail(&root->root_list, &sysctl_table_root.root_list); - spin_unlock(&sysctl_lock); -} - -/* - * sysctl_perm does NOT grant the superuser all rights automatically, because - * some sysctl variables are readonly even to root. - */ - -static int test_perm(int mode, int op) -{ - if (!current_euid()) - mode >>= 6; - else if (in_egroup_p(0)) - mode >>= 3; - if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) - return 0; - return -EACCES; -} - -int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op) -{ - int mode; - - if (root->permissions) - mode = root->permissions(root, current->nsproxy, table); - else - mode = table->mode; - - return test_perm(mode, op); -} - -static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table) -{ - for (; table->procname; table++) { - table->parent = parent; - if (table->child) - sysctl_set_parent(table, table->child); - } -} - -static __init int sysctl_init(void) -{ - sysctl_set_parent(NULL, root_table); -#ifdef CONFIG_SYSCTL_SYSCALL_CHECK - sysctl_check_table(current->nsproxy, root_table); -#endif + register_sysctl_table(sysctl_base_table); return 0; } -core_initcall(sysctl_init); - -static struct ctl_table *is_branch_in(struct ctl_table *branch, - struct ctl_table *table) -{ - struct ctl_table *p; - const char *s = branch->procname; - - /* branch should have named subdirectory as its first element */ - if (!s || !branch->child) - return NULL; - - /* ... and nothing else */ - if (branch[1].procname) - return NULL; - - /* table should contain subdirectory with the same name */ - for (p = table; p->procname; p++) { - if (!p->child) - continue; - if (p->procname && strcmp(p->procname, s) == 0) - return p; - } - return NULL; -} - -/* see if attaching q to p would be an improvement */ -static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q) -{ - struct ctl_table *to = p->ctl_table, *by = q->ctl_table; - struct ctl_table *next; - int is_better = 0; - int not_in_parent = !p->attached_by; - - while ((next = is_branch_in(by, to)) != NULL) { - if (by == q->attached_by) - is_better = 1; - if (to == p->attached_by) - not_in_parent = 1; - by = by->child; - to = next->child; - } - - if (is_better && not_in_parent) { - q->attached_by = by; - q->attached_to = to; - q->parent = p; - } -} - -/** - * __register_sysctl_paths - register a sysctl hierarchy - * @root: List of sysctl headers to register on - * @namespaces: Data to compute which lists of sysctl entries are visible - * @path: The path to the directory the sysctl table is in. - * @table: the top-level table structure - * - * Register a sysctl table hierarchy. @table should be a filled in ctl_table - * array. A completely 0 filled entry terminates the table. - * - * The members of the &struct ctl_table structure are used as follows: - * - * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not - * enter a sysctl file - * - * data - a pointer to data for use by proc_handler - * - * maxlen - the maximum size in bytes of the data - * - * mode - the file permissions for the /proc/sys file, and for sysctl(2) - * - * child - a pointer to the child sysctl table if this entry is a directory, or - * %NULL. - * - * proc_handler - the text handler routine (described below) - * - * de - for internal use by the sysctl routines - * - * extra1, extra2 - extra pointers usable by the proc handler routines - * - * Leaf nodes in the sysctl tree will be represented by a single file - * under /proc; non-leaf nodes will be represented by directories. - * - * sysctl(2) can automatically manage read and write requests through - * the sysctl table. The data and maxlen fields of the ctl_table - * struct enable minimal validation of the values being written to be - * performed, and the mode field allows minimal authentication. - * - * There must be a proc_handler routine for any terminal nodes - * mirrored under /proc/sys (non-terminals are handled by a built-in - * directory handler). Several default handlers are available to - * cover common cases - - * - * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), - * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), - * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() - * - * It is the handler's job to read the input buffer from user memory - * and process it. The handler should return 0 on success. - * - * This routine returns %NULL on a failure to register, and a pointer - * to the table header on success. - */ -struct ctl_table_header *__register_sysctl_paths( - struct ctl_table_root *root, - struct nsproxy *namespaces, - const struct ctl_path *path, struct ctl_table *table) -{ - struct ctl_table_header *header; - struct ctl_table *new, **prevp; - unsigned int n, npath; - struct ctl_table_set *set; - - /* Count the path components */ - for (npath = 0; path[npath].procname; ++npath) - ; - - /* - * For each path component, allocate a 2-element ctl_table array. - * The first array element will be filled with the sysctl entry - * for this, the second will be the sentinel (procname == 0). - * - * We allocate everything in one go so that we don't have to - * worry about freeing additional memory in unregister_sysctl_table. - */ - header = kzalloc(sizeof(struct ctl_table_header) + - (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL); - if (!header) - return NULL; - - new = (struct ctl_table *) (header + 1); - - /* Now connect the dots */ - prevp = &header->ctl_table; - for (n = 0; n < npath; ++n, ++path) { - /* Copy the procname */ - new->procname = path->procname; - new->mode = 0555; - - *prevp = new; - prevp = &new->child; - - new += 2; - } - *prevp = table; - header->ctl_table_arg = table; - - INIT_LIST_HEAD(&header->ctl_entry); - header->used = 0; - header->unregistering = NULL; - header->root = root; - sysctl_set_parent(NULL, header->ctl_table); - header->count = 1; -#ifdef CONFIG_SYSCTL_SYSCALL_CHECK - if (sysctl_check_table(namespaces, header->ctl_table)) { - kfree(header); - return NULL; - } -#endif - spin_lock(&sysctl_lock); - header->set = lookup_header_set(root, namespaces); - header->attached_by = header->ctl_table; - header->attached_to = root_table; - header->parent = &root_table_header; - for (set = header->set; set; set = set->parent) { - struct ctl_table_header *p; - list_for_each_entry(p, &set->list, ctl_entry) { - if (p->unregistering) - continue; - try_attach(p, header); - } - } - header->parent->count++; - list_add_tail(&header->ctl_entry, &header->set->list); - spin_unlock(&sysctl_lock); - - return header; -} - -/** - * register_sysctl_table_path - register a sysctl table hierarchy - * @path: The path to the directory the sysctl table is in. - * @table: the top-level table structure - * - * Register a sysctl table hierarchy. @table should be a filled in ctl_table - * array. A completely 0 filled entry terminates the table. - * - * See __register_sysctl_paths for more details. - */ -struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, - struct ctl_table *table) -{ - return __register_sysctl_paths(&sysctl_table_root, current->nsproxy, - path, table); -} - -/** - * register_sysctl_table - register a sysctl table hierarchy - * @table: the top-level table structure - * - * Register a sysctl table hierarchy. @table should be a filled in ctl_table - * array. A completely 0 filled entry terminates the table. - * - * See register_sysctl_paths for more details. - */ -struct ctl_table_header *register_sysctl_table(struct ctl_table *table) -{ - static const struct ctl_path null_path[] = { {} }; - - return register_sysctl_paths(null_path, table); -} - -/** - * unregister_sysctl_table - unregister a sysctl table hierarchy - * @header: the header returned from register_sysctl_table - * - * Unregisters the sysctl table and all children. proc entries may not - * actually be removed until they are no longer used by anyone. - */ -void unregister_sysctl_table(struct ctl_table_header * header) -{ - might_sleep(); - - if (header == NULL) - return; - - spin_lock(&sysctl_lock); - start_unregistering(header); - if (!--header->parent->count) { - WARN_ON(1); - kfree_rcu(header->parent, rcu); - } - if (!--header->count) - kfree_rcu(header, rcu); - spin_unlock(&sysctl_lock); -} - -int sysctl_is_seen(struct ctl_table_header *p) -{ - struct ctl_table_set *set = p->set; - int res; - spin_lock(&sysctl_lock); - if (p->unregistering) - res = 0; - else if (!set->is_seen) - res = 1; - else - res = set->is_seen(set); - spin_unlock(&sysctl_lock); - return res; -} - -void setup_sysctl_set(struct ctl_table_set *p, - struct ctl_table_set *parent, - int (*is_seen)(struct ctl_table_set *)) -{ - INIT_LIST_HEAD(&p->list); - p->parent = parent ? parent : &sysctl_table_root.default_set; - p->is_seen = is_seen; -} - -#else /* !CONFIG_SYSCTL */ -struct ctl_table_header *register_sysctl_table(struct ctl_table * table) -{ - return NULL; -} - -struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, - struct ctl_table *table) -{ - return NULL; -} - -void unregister_sysctl_table(struct ctl_table_header * table) -{ -} - -void setup_sysctl_set(struct ctl_table_set *p, - struct ctl_table_set *parent, - int (*is_seen)(struct ctl_table_set *)) -{ -} - -void sysctl_head_put(struct ctl_table_header *head) -{ -} - #endif /* CONFIG_SYSCTL */ /* @@ -2431,7 +1943,7 @@ static int proc_taint(struct ctl_table *table, int write, } #ifdef CONFIG_PRINTK -static int proc_dmesg_restrict(struct ctl_table *table, int write, +static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { if (write && !capable(CAP_SYS_ADMIN)) @@ -2884,9 +2396,7 @@ int proc_do_large_bitmap(struct ctl_table *table, int write, } } - while (val_a <= val_b) - set_bit(val_a++, tmp_bitmap); - + bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1); first = 0; proc_skip_char(&kbuf, &left, '\n'); } @@ -2929,8 +2439,7 @@ int proc_do_large_bitmap(struct ctl_table *table, int write, if (*ppos) bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len); else - memcpy(bitmap, tmp_bitmap, - BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long)); + bitmap_copy(bitmap, tmp_bitmap, bitmap_len); } kfree(tmp_bitmap); *lenp -= left; @@ -3008,6 +2517,3 @@ EXPORT_SYMBOL(proc_dointvec_ms_jiffies); EXPORT_SYMBOL(proc_dostring); EXPORT_SYMBOL(proc_doulongvec_minmax); EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax); -EXPORT_SYMBOL(register_sysctl_table); -EXPORT_SYMBOL(register_sysctl_paths); -EXPORT_SYMBOL(unregister_sysctl_table); |