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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /fs/fs_parser.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'fs/fs_parser.c')
-rw-r--r--fs/fs_parser.c390
1 files changed, 390 insertions, 0 deletions
diff --git a/fs/fs_parser.c b/fs/fs_parser.c
new file mode 100644
index 000000000..b4cc4cce5
--- /dev/null
+++ b/fs/fs_parser.c
@@ -0,0 +1,390 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Filesystem parameter parser.
+ *
+ * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/export.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <linux/namei.h>
+#include "internal.h"
+
+static const struct constant_table bool_names[] = {
+ { "0", false },
+ { "1", true },
+ { "false", false },
+ { "no", false },
+ { "true", true },
+ { "yes", true },
+ { },
+};
+
+static const struct constant_table *
+__lookup_constant(const struct constant_table *tbl, const char *name)
+{
+ for ( ; tbl->name; tbl++)
+ if (strcmp(name, tbl->name) == 0)
+ return tbl;
+ return NULL;
+}
+
+/**
+ * lookup_constant - Look up a constant by name in an ordered table
+ * @tbl: The table of constants to search.
+ * @name: The name to look up.
+ * @not_found: The value to return if the name is not found.
+ */
+int lookup_constant(const struct constant_table *tbl, const char *name, int not_found)
+{
+ const struct constant_table *p = __lookup_constant(tbl, name);
+
+ return p ? p->value : not_found;
+}
+EXPORT_SYMBOL(lookup_constant);
+
+static inline bool is_flag(const struct fs_parameter_spec *p)
+{
+ return p->type == NULL;
+}
+
+static const struct fs_parameter_spec *fs_lookup_key(
+ const struct fs_parameter_spec *desc,
+ struct fs_parameter *param, bool *negated)
+{
+ const struct fs_parameter_spec *p, *other = NULL;
+ const char *name = param->key;
+ bool want_flag = param->type == fs_value_is_flag;
+
+ *negated = false;
+ for (p = desc; p->name; p++) {
+ if (strcmp(p->name, name) != 0)
+ continue;
+ if (likely(is_flag(p) == want_flag))
+ return p;
+ other = p;
+ }
+ if (want_flag) {
+ if (name[0] == 'n' && name[1] == 'o' && name[2]) {
+ for (p = desc; p->name; p++) {
+ if (strcmp(p->name, name + 2) != 0)
+ continue;
+ if (!(p->flags & fs_param_neg_with_no))
+ continue;
+ *negated = true;
+ return p;
+ }
+ }
+ }
+ return other;
+}
+
+/*
+ * __fs_parse - Parse a filesystem configuration parameter
+ * @log: The filesystem context to log errors through.
+ * @desc: The parameter description to use.
+ * @param: The parameter.
+ * @result: Where to place the result of the parse
+ *
+ * Parse a filesystem configuration parameter and attempt a conversion for a
+ * simple parameter for which this is requested. If successful, the determined
+ * parameter ID is placed into @result->key, the desired type is indicated in
+ * @result->t and any converted value is placed into an appropriate member of
+ * the union in @result.
+ *
+ * The function returns the parameter number if the parameter was matched,
+ * -ENOPARAM if it wasn't matched and @desc->ignore_unknown indicated that
+ * unknown parameters are okay and -EINVAL if there was a conversion issue or
+ * the parameter wasn't recognised and unknowns aren't okay.
+ */
+int __fs_parse(struct p_log *log,
+ const struct fs_parameter_spec *desc,
+ struct fs_parameter *param,
+ struct fs_parse_result *result)
+{
+ const struct fs_parameter_spec *p;
+
+ result->uint_64 = 0;
+
+ p = fs_lookup_key(desc, param, &result->negated);
+ if (!p)
+ return -ENOPARAM;
+
+ if (p->flags & fs_param_deprecated)
+ warn_plog(log, "Deprecated parameter '%s'", param->key);
+
+ /* Try to turn the type we were given into the type desired by the
+ * parameter and give an error if we can't.
+ */
+ if (is_flag(p)) {
+ if (param->type != fs_value_is_flag)
+ return inval_plog(log, "Unexpected value for '%s'",
+ param->key);
+ result->boolean = !result->negated;
+ } else {
+ int ret = p->type(log, p, param, result);
+ if (ret)
+ return ret;
+ }
+ return p->opt;
+}
+EXPORT_SYMBOL(__fs_parse);
+
+/**
+ * fs_lookup_param - Look up a path referred to by a parameter
+ * @fc: The filesystem context to log errors through.
+ * @param: The parameter.
+ * @want_bdev: T if want a blockdev
+ * @flags: Pathwalk flags passed to filename_lookup()
+ * @_path: The result of the lookup
+ */
+int fs_lookup_param(struct fs_context *fc,
+ struct fs_parameter *param,
+ bool want_bdev,
+ unsigned int flags,
+ struct path *_path)
+{
+ struct filename *f;
+ bool put_f;
+ int ret;
+
+ switch (param->type) {
+ case fs_value_is_string:
+ f = getname_kernel(param->string);
+ if (IS_ERR(f))
+ return PTR_ERR(f);
+ param->dirfd = AT_FDCWD;
+ put_f = true;
+ break;
+ case fs_value_is_filename:
+ f = param->name;
+ put_f = false;
+ break;
+ default:
+ return invalf(fc, "%s: not usable as path", param->key);
+ }
+
+ ret = filename_lookup(param->dirfd, f, flags, _path, NULL);
+ if (ret < 0) {
+ errorf(fc, "%s: Lookup failure for '%s'", param->key, f->name);
+ goto out;
+ }
+
+ if (want_bdev &&
+ !S_ISBLK(d_backing_inode(_path->dentry)->i_mode)) {
+ path_put(_path);
+ _path->dentry = NULL;
+ _path->mnt = NULL;
+ errorf(fc, "%s: Non-blockdev passed as '%s'",
+ param->key, f->name);
+ ret = -ENOTBLK;
+ }
+
+out:
+ if (put_f)
+ putname(f);
+ return ret;
+}
+EXPORT_SYMBOL(fs_lookup_param);
+
+static int fs_param_bad_value(struct p_log *log, struct fs_parameter *param)
+{
+ return inval_plog(log, "Bad value for '%s'", param->key);
+}
+
+int fs_param_is_bool(struct p_log *log, const struct fs_parameter_spec *p,
+ struct fs_parameter *param, struct fs_parse_result *result)
+{
+ int b;
+ if (param->type != fs_value_is_string)
+ return fs_param_bad_value(log, param);
+ if (!*param->string && (p->flags & fs_param_can_be_empty))
+ return 0;
+ b = lookup_constant(bool_names, param->string, -1);
+ if (b == -1)
+ return fs_param_bad_value(log, param);
+ result->boolean = b;
+ return 0;
+}
+EXPORT_SYMBOL(fs_param_is_bool);
+
+int fs_param_is_u32(struct p_log *log, const struct fs_parameter_spec *p,
+ struct fs_parameter *param, struct fs_parse_result *result)
+{
+ int base = (unsigned long)p->data;
+ if (param->type != fs_value_is_string)
+ return fs_param_bad_value(log, param);
+ if (!*param->string && (p->flags & fs_param_can_be_empty))
+ return 0;
+ if (kstrtouint(param->string, base, &result->uint_32) < 0)
+ return fs_param_bad_value(log, param);
+ return 0;
+}
+EXPORT_SYMBOL(fs_param_is_u32);
+
+int fs_param_is_s32(struct p_log *log, const struct fs_parameter_spec *p,
+ struct fs_parameter *param, struct fs_parse_result *result)
+{
+ if (param->type != fs_value_is_string)
+ return fs_param_bad_value(log, param);
+ if (!*param->string && (p->flags & fs_param_can_be_empty))
+ return 0;
+ if (kstrtoint(param->string, 0, &result->int_32) < 0)
+ return fs_param_bad_value(log, param);
+ return 0;
+}
+EXPORT_SYMBOL(fs_param_is_s32);
+
+int fs_param_is_u64(struct p_log *log, const struct fs_parameter_spec *p,
+ struct fs_parameter *param, struct fs_parse_result *result)
+{
+ if (param->type != fs_value_is_string)
+ return fs_param_bad_value(log, param);
+ if (!*param->string && (p->flags & fs_param_can_be_empty))
+ return 0;
+ if (kstrtoull(param->string, 0, &result->uint_64) < 0)
+ return fs_param_bad_value(log, param);
+ return 0;
+}
+EXPORT_SYMBOL(fs_param_is_u64);
+
+int fs_param_is_enum(struct p_log *log, const struct fs_parameter_spec *p,
+ struct fs_parameter *param, struct fs_parse_result *result)
+{
+ const struct constant_table *c;
+ if (param->type != fs_value_is_string)
+ return fs_param_bad_value(log, param);
+ if (!*param->string && (p->flags & fs_param_can_be_empty))
+ return 0;
+ c = __lookup_constant(p->data, param->string);
+ if (!c)
+ return fs_param_bad_value(log, param);
+ result->uint_32 = c->value;
+ return 0;
+}
+EXPORT_SYMBOL(fs_param_is_enum);
+
+int fs_param_is_string(struct p_log *log, const struct fs_parameter_spec *p,
+ struct fs_parameter *param, struct fs_parse_result *result)
+{
+ if (param->type != fs_value_is_string ||
+ (!*param->string && !(p->flags & fs_param_can_be_empty)))
+ return fs_param_bad_value(log, param);
+ return 0;
+}
+EXPORT_SYMBOL(fs_param_is_string);
+
+int fs_param_is_fd(struct p_log *log, const struct fs_parameter_spec *p,
+ struct fs_parameter *param, struct fs_parse_result *result)
+{
+ switch (param->type) {
+ case fs_value_is_string:
+ if ((!*param->string && !(p->flags & fs_param_can_be_empty)) ||
+ kstrtouint(param->string, 0, &result->uint_32) < 0)
+ break;
+ if (result->uint_32 <= INT_MAX)
+ return 0;
+ break;
+ case fs_value_is_file:
+ result->uint_32 = param->dirfd;
+ if (result->uint_32 <= INT_MAX)
+ return 0;
+ break;
+ default:
+ break;
+ }
+ return fs_param_bad_value(log, param);
+}
+EXPORT_SYMBOL(fs_param_is_fd);
+
+int fs_param_is_file_or_string(struct p_log *log,
+ const struct fs_parameter_spec *p,
+ struct fs_parameter *param,
+ struct fs_parse_result *result)
+{
+ switch (param->type) {
+ case fs_value_is_string:
+ return fs_param_is_string(log, p, param, result);
+ case fs_value_is_file:
+ result->uint_32 = param->dirfd;
+ if (result->uint_32 <= INT_MAX)
+ return 0;
+ break;
+ default:
+ break;
+ }
+ return fs_param_bad_value(log, param);
+}
+EXPORT_SYMBOL(fs_param_is_file_or_string);
+
+int fs_param_is_uid(struct p_log *log, const struct fs_parameter_spec *p,
+ struct fs_parameter *param, struct fs_parse_result *result)
+{
+ kuid_t uid;
+
+ if (fs_param_is_u32(log, p, param, result) != 0)
+ return fs_param_bad_value(log, param);
+
+ uid = make_kuid(current_user_ns(), result->uint_32);
+ if (!uid_valid(uid))
+ return inval_plog(log, "Invalid uid '%s'", param->string);
+
+ result->uid = uid;
+ return 0;
+}
+EXPORT_SYMBOL(fs_param_is_uid);
+
+int fs_param_is_gid(struct p_log *log, const struct fs_parameter_spec *p,
+ struct fs_parameter *param, struct fs_parse_result *result)
+{
+ kgid_t gid;
+
+ if (fs_param_is_u32(log, p, param, result) != 0)
+ return fs_param_bad_value(log, param);
+
+ gid = make_kgid(current_user_ns(), result->uint_32);
+ if (!gid_valid(gid))
+ return inval_plog(log, "Invalid gid '%s'", param->string);
+
+ result->gid = gid;
+ return 0;
+}
+EXPORT_SYMBOL(fs_param_is_gid);
+
+int fs_param_is_blockdev(struct p_log *log, const struct fs_parameter_spec *p,
+ struct fs_parameter *param, struct fs_parse_result *result)
+{
+ return 0;
+}
+EXPORT_SYMBOL(fs_param_is_blockdev);
+
+#ifdef CONFIG_VALIDATE_FS_PARSER
+/**
+ * fs_validate_description - Validate a parameter specification array
+ * @name: Owner name of the parameter specification array
+ * @desc: The parameter specification array to validate.
+ */
+bool fs_validate_description(const char *name,
+ const struct fs_parameter_spec *desc)
+{
+ const struct fs_parameter_spec *param, *p2;
+ bool good = true;
+
+ for (param = desc; param->name; param++) {
+ /* Check for duplicate parameter names */
+ for (p2 = desc; p2 < param; p2++) {
+ if (strcmp(param->name, p2->name) == 0) {
+ if (is_flag(param) != is_flag(p2))
+ continue;
+ pr_err("VALIDATE %s: PARAM[%s]: Duplicate\n",
+ name, param->name);
+ good = false;
+ }
+ }
+ }
+ return good;
+}
+#endif /* CONFIG_VALIDATE_FS_PARSER */