cgroup1: switch to option-by-option parsing (8d2451f4) · Commits · e / devices / android_kernel_fairphone_FP5

kernel/cgroup/cgroup-internal.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -257,14 +257,15 @@ extern const struct proc_ns_operations cgroupns_operations;
		*/
		extern struct cftype cgroup1_base_files[];
		extern struct kernfs_syscall_ops cgroup1_kf_syscall_ops;
		extern const struct fs_parameter_description cgroup1_fs_parameters;

		int proc_cgroupstats_show(struct seq_file m, void v);
		bool cgroup1_ssid_disabled(int ssid);
		void cgroup1_pidlist_destroy_all(struct cgroup *cgrp);
		void cgroup1_release_agent(struct work_struct *work);
		void cgroup1_check_for_release(struct cgroup *cgrp);
		int cgroup1_parse_param(struct fs_context fc, struct fs_parameter param);
		int cgroup1_get_tree(struct fs_context *fc);
		int parse_cgroup1_options(char data, struct cgroup_fs_context ctx);
		int cgroup1_reconfigure(struct fs_context *ctx);

		#endif /* __CGROUP_INTERNAL_H */

kernel/cgroup/cgroup-v1.c

+109 −83

Original line number	Diff line number	Diff line
		@@ -13,9 +13,12 @@
		#include <linux/delayacct.h>
		#include <linux/pid_namespace.h>
		#include <linux/cgroupstats.h>
		#include <linux/fs_parser.h>

		#include <trace/events/cgroup.h>

		#define cg_invalf(fc, fmt, ...) ({ pr_err(fmt, ## __VA_ARGS__); -EINVAL; })

		/*
		* pidlists linger the following amount before being destroyed. The goal
		* is avoiding frequent destruction in the middle of consecutive read calls
		@@ -906,94 +909,117 @@ static int cgroup1_show_options(struct seq_file seq, struct kernfs_root kf_roo
		return 0;
		}

		int parse_cgroup1_options(char data, struct cgroup_fs_context ctx)
		enum cgroup1_param {
		Opt_all,
		Opt_clone_children,
		Opt_cpuset_v2_mode,
		Opt_name,
		Opt_none,
		Opt_noprefix,
		Opt_release_agent,
		Opt_xattr,
		};

		static const struct fs_parameter_spec cgroup1_param_specs[] = {
		fsparam_flag ("all", Opt_all),
		fsparam_flag ("clone_children", Opt_clone_children),
		fsparam_flag ("cpuset_v2_mode", Opt_cpuset_v2_mode),
		fsparam_string("name", Opt_name),
		fsparam_flag ("none", Opt_none),
		fsparam_flag ("noprefix", Opt_noprefix),
		fsparam_string("release_agent", Opt_release_agent),
		fsparam_flag ("xattr", Opt_xattr),
		{}
		};

		const struct fs_parameter_description cgroup1_fs_parameters = {
		.name = "cgroup1",
		.specs = cgroup1_param_specs,
		};

		int cgroup1_parse_param(struct fs_context fc, struct fs_parameter param)
		{
		char token, o = data;
		struct cgroup_fs_context *ctx = cgroup_fc2context(fc);
		struct cgroup_subsys *ss;
		int i;
		struct fs_parse_result result;
		int opt, i;

		opt = fs_parse(fc, &cgroup1_fs_parameters, param, &result);
		if (opt == -ENOPARAM) {
		if (strcmp(param->key, "source") == 0) {
		fc->source = param->string;
		param->string = NULL;
		return 0;
		}
		for_each_subsys(ss, i) {
		if (strcmp(param->key, ss->legacy_name))
		continue;
		ctx->subsys_mask \|= (1 << i);
		return 0;
		}
		return cg_invalf(fc, "cgroup1: Unknown subsys name '%s'", param->key);
		}
		if (opt < 0)
		return opt;

		while ((token = strsep(&o, ",")) != NULL) {
		if (!*token)
		return -EINVAL;
		if (!strcmp(token, "none")) {
		switch (opt) {
		case Opt_none:
		/* Explicitly have no subsystems */
		ctx->none = true;
		continue;
		}
		if (!strcmp(token, "all")) {
		break;
		case Opt_all:
		ctx->all_ss = true;
		continue;
		}
		if (!strcmp(token, "noprefix")) {
		break;
		case Opt_noprefix:
		ctx->flags \|= CGRP_ROOT_NOPREFIX;
		continue;
		}
		if (!strcmp(token, "clone_children")) {
		break;
		case Opt_clone_children:
		ctx->cpuset_clone_children = true;
		continue;
		}
		if (!strcmp(token, "cpuset_v2_mode")) {
		break;
		case Opt_cpuset_v2_mode:
		ctx->flags \|= CGRP_ROOT_CPUSET_V2_MODE;
		continue;
		}
		if (!strcmp(token, "xattr")) {
		break;
		case Opt_xattr:
		ctx->flags \|= CGRP_ROOT_XATTR;
		continue;
		}
		if (!strncmp(token, "release_agent=", 14)) {
		break;
		case Opt_release_agent:
		/* Specifying two release agents is forbidden */
		if (ctx->release_agent)
		return -EINVAL;
		ctx->release_agent =
		kstrndup(token + 14, PATH_MAX - 1, GFP_KERNEL);
		if (!ctx->release_agent)
		return -ENOMEM;
		continue;
		}
		if (!strncmp(token, "name=", 5)) {
		const char *name = token + 5;

		return cg_invalf(fc, "cgroup1: release_agent respecified");
		ctx->release_agent = param->string;
		param->string = NULL;
		break;
		case Opt_name:
		/* blocked by boot param? */
		if (cgroup_no_v1_named)
		return -ENOENT;
		/* Can't specify an empty name */
		if (!strlen(name))
		return -EINVAL;
		if (!param->size)
		return cg_invalf(fc, "cgroup1: Empty name");
		if (param->size > MAX_CGROUP_ROOT_NAMELEN - 1)
		return cg_invalf(fc, "cgroup1: Name too long");
		/* Must match [\w.-]+ */
		for (i = 0; i < strlen(name); i++) {
		char c = name[i];
		for (i = 0; i < param->size; i++) {
		char c = param->string[i];
		if (isalnum(c))
		continue;
		if ((c == '.') \|\| (c == '-') \|\| (c == '_'))
		continue;
		return -EINVAL;
		return cg_invalf(fc, "cgroup1: Invalid name");
		}
		/* Specifying two names is forbidden */
		if (ctx->name)
		return -EINVAL;
		ctx->name = kstrndup(name,
		MAX_CGROUP_ROOT_NAMELEN - 1,
		GFP_KERNEL);
		if (!ctx->name)
		return -ENOMEM;

		continue;
		}

		for_each_subsys(ss, i) {
		if (strcmp(token, ss->legacy_name))
		continue;
		ctx->subsys_mask \|= (1 << i);
		return cg_invalf(fc, "cgroup1: name respecified");
		ctx->name = param->string;
		param->string = NULL;
		break;
		}
		if (i == CGROUP_SUBSYS_COUNT)
		return -ENOENT;
		}
		return 0;
		}

		static int check_cgroupfs_options(struct cgroup_fs_context *ctx)
		static int check_cgroupfs_options(struct fs_context *fc)
		{
		struct cgroup_fs_context *ctx = cgroup_fc2context(fc);
		u16 mask = U16_MAX;
		u16 enabled = 0;
		struct cgroup_subsys *ss;
		@@ -1018,7 +1044,7 @@ static int check_cgroupfs_options(struct cgroup_fs_context *ctx)
		if (ctx->all_ss) {
		/* Mutually exclusive option 'all' + subsystem name */
		if (ctx->subsys_mask)
		return -EINVAL;
		return cg_invalf(fc, "cgroup1: subsys name conflicts with all");
		/* 'all' => select all the subsystems */
		ctx->subsys_mask = enabled;
		}
		@@ -1028,7 +1054,7 @@ static int check_cgroupfs_options(struct cgroup_fs_context *ctx)
		* empty hierarchies must have a name).
		*/
		if (!ctx->subsys_mask && !ctx->name)
		return -EINVAL;
		return cg_invalf(fc, "cgroup1: Need name or subsystem set");

		/*
		* Option noprefix was introduced just for backward compatibility
		@@ -1036,11 +1062,11 @@ static int check_cgroupfs_options(struct cgroup_fs_context *ctx)
		* the cpuset subsystem.
		*/
		if ((ctx->flags & CGRP_ROOT_NOPREFIX) && (ctx->subsys_mask & mask))
		return -EINVAL;
		return cg_invalf(fc, "cgroup1: noprefix used incorrectly");

		/* Can't specify "none" and some subsystems */
		if (ctx->subsys_mask && ctx->none)
		return -EINVAL;
		return cg_invalf(fc, "cgroup1: none used incorrectly");

		return 0;
		}
		@@ -1056,7 +1082,7 @@ int cgroup1_reconfigure(struct fs_context *fc)
		cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);

		/* See what subsystems are wanted */
		ret = check_cgroupfs_options(ctx);
		ret = check_cgroupfs_options(fc);
		if (ret)
		goto out_unlock;

		@@ -1070,7 +1096,7 @@ int cgroup1_reconfigure(struct fs_context *fc)
		/* Don't allow flags or name to change at remount */
		if ((ctx->flags ^ root->flags) \|\|
		(ctx->name && strcmp(ctx->name, root->name))) {
		pr_err("option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"\n",
		cg_invalf(fc, "option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"",
		ctx->flags, ctx->name ?: "", root->flags, root->name);
		ret = -EINVAL;
		goto out_unlock;
		@@ -1125,7 +1151,7 @@ int cgroup1_get_tree(struct fs_context *fc)
		cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);

		/* First find the desired set of subsystems */
		ret = check_cgroupfs_options(ctx);
		ret = check_cgroupfs_options(fc);
		if (ret)
		goto out_unlock;

		@@ -1192,7 +1218,7 @@ int cgroup1_get_tree(struct fs_context *fc)
		* can't create new one without subsys specification.
		*/
		if (!ctx->subsys_mask && !ctx->none) {
		ret = -EINVAL;
		ret = cg_invalf(fc, "cgroup1: No subsys list or none specified");
		goto out_unlock;
		}

kernel/cgroup/cgroup.c

+6 −14

Original line number	Diff line number	Diff line
		@@ -2083,15 +2083,6 @@ static int cgroup_parse_monolithic(struct fs_context fc, void data)
		return parse_cgroup_root_flags(data, &ctx->flags);
		}

		static int cgroup1_parse_monolithic(struct fs_context fc, void data)
		{
		struct cgroup_fs_context *ctx = cgroup_fc2context(fc);

		if (data)
		security_sb_eat_lsm_opts(data, &fc->security);
		return parse_cgroup1_options(data, ctx);
		}

		static int cgroup_get_tree(struct fs_context *fc)
		{
		struct cgroup_namespace *ns = current->nsproxy->cgroup_ns;
		@@ -2124,7 +2115,7 @@ static const struct fs_context_operations cgroup_fs_context_ops = {

		static const struct fs_context_operations cgroup1_fs_context_ops = {
		.free = cgroup_fs_context_free,
		.parse_monolithic = cgroup1_parse_monolithic,
		.parse_param = cgroup1_parse_param,
		.get_tree = cgroup1_get_tree,
		.reconfigure = cgroup1_reconfigure,
		};
		@@ -2177,6 +2168,7 @@ static void cgroup_kill_sb(struct super_block *sb)
		struct file_system_type cgroup_fs_type = {
		.name = "cgroup",
		.init_fs_context = cgroup_init_fs_context,
		.parameters = &cgroup1_fs_parameters,
		.kill_sb = cgroup_kill_sb,
		.fs_flags = FS_USERNS_MOUNT,
		};