Joe Perches <j...@perches.com> writes: > Couple more bikesheddy things: > > Is there ever a reason to use a non __builtin_const_p(perms)?
It's a bit conservative, and anyway, the test is useless since AFAICT BUILD_BUG_ON() is a noop if !__builtin_const_p(). I removed it and re-tested. > Maybe that should be a BUILD_BUG_ON too > BUILD_BUG_ON(!builtin_const_p_perms) > > My brain of little size gets confused by the > BUILD_BUG_ON_ZERO(foo) + > vs > BUILD_BUG_ON(foo); > as it just seems like more text for the same content. > > Is there any value on the "_ZERO(foo) +" I don't understand? I don't like to use statement expressions unless we really need them, and BUILD_BUG_ON_ZERO() was build for this purpose. Cheers, Rusty. Subject: VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms. Summary of http://lkml.org/lkml/2014/3/14/363 : Ted: module_param(queue_depth, int, 444) Joe: 0444! Rusty: User perms >= group perms >= other perms? Joe: CLASS_ATTR, DEVICE_ATTR, SENSOR_ATTR and SENSOR_ATTR_2? Side effect of stricter permissions means removing the unnecessary S_IFREG from several callers. Suggested-by: Joe Perches <j...@perches.com> Acked-by: Bjorn Helgaas <bhelg...@google.com> for drivers/pci/slot.c Acked-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> Cc: Miklos Szeredi <mik...@szeredi.hu> Cc: Mark Fasheh <mfas...@suse.com> Cc: Joel Becker <jl...@evilplan.org> Signed-off-by: Rusty Russell <ru...@rustcorp.com.au> diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c index 7dd62fa9d0bd..396c200b9ddb 100644 --- a/drivers/pci/slot.c +++ b/drivers/pci/slot.c @@ -116,11 +116,11 @@ static void pci_slot_release(struct kobject *kobj) } static struct pci_slot_attribute pci_slot_attr_address = - __ATTR(address, (S_IFREG | S_IRUGO), address_read_file, NULL); + __ATTR(address, S_IRUGO, address_read_file, NULL); static struct pci_slot_attribute pci_slot_attr_max_speed = - __ATTR(max_bus_speed, (S_IFREG | S_IRUGO), max_speed_read_file, NULL); + __ATTR(max_bus_speed, S_IRUGO, max_speed_read_file, NULL); static struct pci_slot_attribute pci_slot_attr_cur_speed = - __ATTR(cur_bus_speed, (S_IFREG | S_IRUGO), cur_speed_read_file, NULL); + __ATTR(cur_bus_speed, S_IRUGO, cur_speed_read_file, NULL); static struct attribute *pci_slot_default_attrs[] = { &pci_slot_attr_address.attr, diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c index b96a49b37d66..77cf5eeeabd1 100644 --- a/fs/fuse/cuse.c +++ b/fs/fuse/cuse.c @@ -568,7 +568,7 @@ static ssize_t cuse_class_waiting_show(struct device *dev, return sprintf(buf, "%d\n", atomic_read(&cc->fc.num_waiting)); } -static DEVICE_ATTR(waiting, S_IFREG | 0400, cuse_class_waiting_show, NULL); +static DEVICE_ATTR(waiting, 0400, cuse_class_waiting_show, NULL); static ssize_t cuse_class_abort_store(struct device *dev, struct device_attribute *attr, @@ -579,7 +579,7 @@ static ssize_t cuse_class_abort_store(struct device *dev, fuse_abort_conn(&cc->fc); return count; } -static DEVICE_ATTR(abort, S_IFREG | 0200, NULL, cuse_class_abort_store); +static DEVICE_ATTR(abort, 0200, NULL, cuse_class_abort_store); static struct attribute *cuse_class_dev_attrs[] = { &dev_attr_waiting.attr, diff --git a/fs/ocfs2/cluster/sys.c b/fs/ocfs2/cluster/sys.c index a4b07730b2e1..b7f57271d49c 100644 --- a/fs/ocfs2/cluster/sys.c +++ b/fs/ocfs2/cluster/sys.c @@ -41,7 +41,7 @@ static ssize_t version_show(struct kobject *kobj, struct kobj_attribute *attr, return snprintf(buf, PAGE_SIZE, "%u\n", O2NM_API_VERSION); } static struct kobj_attribute attr_version = - __ATTR(interface_revision, S_IFREG | S_IRUGO, version_show, NULL); + __ATTR(interface_revision, S_IRUGO, version_show, NULL); static struct attribute *o2cb_attrs[] = { &attr_version.attr, diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c index 1324e6600e57..25e9f7b5bad3 100644 --- a/fs/ocfs2/stackglue.c +++ b/fs/ocfs2/stackglue.c @@ -494,7 +494,7 @@ static ssize_t ocfs2_max_locking_protocol_show(struct kobject *kobj, } static struct kobj_attribute ocfs2_attr_max_locking_protocol = - __ATTR(max_locking_protocol, S_IFREG | S_IRUGO, + __ATTR(max_locking_protocol, S_IRUGO, ocfs2_max_locking_protocol_show, NULL); static ssize_t ocfs2_loaded_cluster_plugins_show(struct kobject *kobj, @@ -526,7 +526,7 @@ static ssize_t ocfs2_loaded_cluster_plugins_show(struct kobject *kobj, } static struct kobj_attribute ocfs2_attr_loaded_cluster_plugins = - __ATTR(loaded_cluster_plugins, S_IFREG | S_IRUGO, + __ATTR(loaded_cluster_plugins, S_IRUGO, ocfs2_loaded_cluster_plugins_show, NULL); static ssize_t ocfs2_active_cluster_plugin_show(struct kobject *kobj, @@ -548,7 +548,7 @@ static ssize_t ocfs2_active_cluster_plugin_show(struct kobject *kobj, } static struct kobj_attribute ocfs2_attr_active_cluster_plugin = - __ATTR(active_cluster_plugin, S_IFREG | S_IRUGO, + __ATTR(active_cluster_plugin, S_IRUGO, ocfs2_active_cluster_plugin_show, NULL); static ssize_t ocfs2_cluster_stack_show(struct kobject *kobj, @@ -597,7 +597,7 @@ static ssize_t ocfs2_cluster_stack_store(struct kobject *kobj, static struct kobj_attribute ocfs2_attr_cluster_stack = - __ATTR(cluster_stack, S_IFREG | S_IRUGO | S_IWUSR, + __ATTR(cluster_stack, S_IRUGO | S_IWUSR, ocfs2_cluster_stack_show, ocfs2_cluster_stack_store); diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 471090093c67..4679eddc110a 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -842,4 +842,12 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD #endif +/* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */ +#define VERIFY_OCTAL_PERMISSIONS(perms) \ + (BUILD_BUG_ON_ZERO((perms) < 0) + \ + BUILD_BUG_ON_ZERO((perms) > 0777) + \ + /* User perms >= group perms >= other perms */ \ + BUILD_BUG_ON_ZERO(((perms) >> 6) < (((perms) >> 3) & 7)) + \ + BUILD_BUG_ON_ZERO((((perms) >> 3) & 7) < ((perms) & 7)) + \ + (perms)) #endif diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 175f6995d1af..204a67743804 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -186,14 +186,12 @@ struct kparam_array parameters. */ #define __module_param_call(prefix, name, ops, arg, perm, level) \ /* Default value instead of permissions? */ \ - static int __param_perm_check_##name __attribute__((unused)) = \ - BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \ - + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \ - static const char __param_str_##name[] = prefix #name; \ + static const char __param_str_##name[] = prefix #name; \ static struct kernel_param __moduleparam_const __param_##name \ __used \ __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \ - = { __param_str_##name, ops, perm, level, { arg } } + = { __param_str_##name, ops, VERIFY_OCTAL_PERMISSIONS(perm), \ + level, { arg } } /* Obsolete - use module_param_cb() */ #define module_param_call(name, set, get, arg, perm) \ diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 30b2ebee6439..f517e6e488c8 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -71,7 +71,8 @@ struct attribute_group { */ #define __ATTR(_name, _mode, _show, _store) { \ - .attr = {.name = __stringify(_name), .mode = _mode }, \ + .attr = {.name = __stringify(_name), \ + .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \ .show = _show, \ .store = _store, \ } _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
