summaryrefslogtreecommitdiffstats
path: root/fs/proc_namespace.c
diff options
context:
space:
mode:
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/proc_namespace.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/proc_namespace.c')
-rw-r--r--fs/proc_namespace.c337
1 files changed, 337 insertions, 0 deletions
diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
new file mode 100644
index 000000000..036356c0a
--- /dev/null
+++ b/fs/proc_namespace.c
@@ -0,0 +1,337 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/proc_namespace.c - handling of /proc/<pid>/{mounts,mountinfo,mountstats}
+ *
+ * In fact, that's a piece of procfs; it's *almost* isolated from
+ * the rest of fs/proc, but has rather close relationships with
+ * fs/namespace.c, thus here instead of fs/proc
+ *
+ */
+#include <linux/mnt_namespace.h>
+#include <linux/nsproxy.h>
+#include <linux/security.h>
+#include <linux/fs_struct.h>
+#include <linux/sched/task.h>
+
+#include "proc/internal.h" /* only for get_proc_task() in ->open() */
+
+#include "pnode.h"
+#include "internal.h"
+
+static __poll_t mounts_poll(struct file *file, poll_table *wait)
+{
+ struct seq_file *m = file->private_data;
+ struct proc_mounts *p = m->private;
+ struct mnt_namespace *ns = p->ns;
+ __poll_t res = EPOLLIN | EPOLLRDNORM;
+ int event;
+
+ poll_wait(file, &p->ns->poll, wait);
+
+ event = READ_ONCE(ns->event);
+ if (m->poll_event != event) {
+ m->poll_event = event;
+ res |= EPOLLERR | EPOLLPRI;
+ }
+
+ return res;
+}
+
+struct proc_fs_opts {
+ int flag;
+ const char *str;
+};
+
+static int show_sb_opts(struct seq_file *m, struct super_block *sb)
+{
+ static const struct proc_fs_opts fs_opts[] = {
+ { SB_SYNCHRONOUS, ",sync" },
+ { SB_DIRSYNC, ",dirsync" },
+ { SB_MANDLOCK, ",mand" },
+ { SB_LAZYTIME, ",lazytime" },
+ { 0, NULL }
+ };
+ const struct proc_fs_opts *fs_infop;
+
+ for (fs_infop = fs_opts; fs_infop->flag; fs_infop++) {
+ if (sb->s_flags & fs_infop->flag)
+ seq_puts(m, fs_infop->str);
+ }
+
+ return security_sb_show_options(m, sb);
+}
+
+static void show_vfsmnt_opts(struct seq_file *m, struct vfsmount *mnt)
+{
+ static const struct proc_fs_opts mnt_opts[] = {
+ { MNT_NOSUID, ",nosuid" },
+ { MNT_NODEV, ",nodev" },
+ { MNT_NOEXEC, ",noexec" },
+ { MNT_NOATIME, ",noatime" },
+ { MNT_NODIRATIME, ",nodiratime" },
+ { MNT_RELATIME, ",relatime" },
+ { MNT_NOSYMFOLLOW, ",nosymfollow" },
+ { 0, NULL }
+ };
+ const struct proc_fs_opts *fs_infop;
+
+ for (fs_infop = mnt_opts; fs_infop->flag; fs_infop++) {
+ if (mnt->mnt_flags & fs_infop->flag)
+ seq_puts(m, fs_infop->str);
+ }
+
+ if (is_idmapped_mnt(mnt))
+ seq_puts(m, ",idmapped");
+}
+
+static inline void mangle(struct seq_file *m, const char *s)
+{
+ seq_escape(m, s, " \t\n\\#");
+}
+
+static void show_type(struct seq_file *m, struct super_block *sb)
+{
+ mangle(m, sb->s_type->name);
+ if (sb->s_subtype) {
+ seq_putc(m, '.');
+ mangle(m, sb->s_subtype);
+ }
+}
+
+static int show_vfsmnt(struct seq_file *m, struct vfsmount *mnt)
+{
+ struct proc_mounts *p = m->private;
+ struct mount *r = real_mount(mnt);
+ struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
+ struct super_block *sb = mnt_path.dentry->d_sb;
+ int err;
+
+ if (sb->s_op->show_devname) {
+ err = sb->s_op->show_devname(m, mnt_path.dentry);
+ if (err)
+ goto out;
+ } else {
+ mangle(m, r->mnt_devname);
+ }
+ seq_putc(m, ' ');
+ /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
+ err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
+ if (err)
+ goto out;
+ seq_putc(m, ' ');
+ show_type(m, sb);
+ seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
+ err = show_sb_opts(m, sb);
+ if (err)
+ goto out;
+ show_vfsmnt_opts(m, mnt);
+ if (sb->s_op->show_options)
+ err = sb->s_op->show_options(m, mnt_path.dentry);
+ seq_puts(m, " 0 0\n");
+out:
+ return err;
+}
+
+static int show_mountinfo(struct seq_file *m, struct vfsmount *mnt)
+{
+ struct proc_mounts *p = m->private;
+ struct mount *r = real_mount(mnt);
+ struct super_block *sb = mnt->mnt_sb;
+ struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
+ int err;
+
+ seq_printf(m, "%i %i %u:%u ", r->mnt_id, r->mnt_parent->mnt_id,
+ MAJOR(sb->s_dev), MINOR(sb->s_dev));
+ err = show_path(m, mnt->mnt_root);
+ if (err)
+ goto out;
+ seq_putc(m, ' ');
+
+ /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
+ err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
+ if (err)
+ goto out;
+
+ seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");
+ show_vfsmnt_opts(m, mnt);
+
+ /* Tagged fields ("foo:X" or "bar") */
+ if (IS_MNT_SHARED(r))
+ seq_printf(m, " shared:%i", r->mnt_group_id);
+ if (IS_MNT_SLAVE(r)) {
+ int master = r->mnt_master->mnt_group_id;
+ int dom = get_dominating_id(r, &p->root);
+ seq_printf(m, " master:%i", master);
+ if (dom && dom != master)
+ seq_printf(m, " propagate_from:%i", dom);
+ }
+ if (IS_MNT_UNBINDABLE(r))
+ seq_puts(m, " unbindable");
+
+ /* Filesystem specific data */
+ seq_puts(m, " - ");
+ show_type(m, sb);
+ seq_putc(m, ' ');
+ if (sb->s_op->show_devname) {
+ err = sb->s_op->show_devname(m, mnt->mnt_root);
+ if (err)
+ goto out;
+ } else {
+ mangle(m, r->mnt_devname);
+ }
+ seq_puts(m, sb_rdonly(sb) ? " ro" : " rw");
+ err = show_sb_opts(m, sb);
+ if (err)
+ goto out;
+ if (sb->s_op->show_options)
+ err = sb->s_op->show_options(m, mnt->mnt_root);
+ seq_putc(m, '\n');
+out:
+ return err;
+}
+
+static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
+{
+ struct proc_mounts *p = m->private;
+ struct mount *r = real_mount(mnt);
+ struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
+ struct super_block *sb = mnt_path.dentry->d_sb;
+ int err;
+
+ /* device */
+ seq_puts(m, "device ");
+ if (sb->s_op->show_devname) {
+ err = sb->s_op->show_devname(m, mnt_path.dentry);
+ if (err)
+ goto out;
+ } else {
+ mangle(m, r->mnt_devname);
+ }
+
+ /* mount point */
+ seq_puts(m, " mounted on ");
+ /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
+ err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
+ if (err)
+ goto out;
+ seq_putc(m, ' ');
+
+ /* file system type */
+ seq_puts(m, "with fstype ");
+ show_type(m, sb);
+
+ /* optional statistics */
+ if (sb->s_op->show_stats) {
+ seq_putc(m, ' ');
+ err = sb->s_op->show_stats(m, mnt_path.dentry);
+ }
+
+ seq_putc(m, '\n');
+out:
+ return err;
+}
+
+static int mounts_open_common(struct inode *inode, struct file *file,
+ int (*show)(struct seq_file *, struct vfsmount *))
+{
+ struct task_struct *task = get_proc_task(inode);
+ struct nsproxy *nsp;
+ struct mnt_namespace *ns = NULL;
+ struct path root;
+ struct proc_mounts *p;
+ struct seq_file *m;
+ int ret = -EINVAL;
+
+ if (!task)
+ goto err;
+
+ task_lock(task);
+ nsp = task->nsproxy;
+ if (!nsp || !nsp->mnt_ns) {
+ task_unlock(task);
+ put_task_struct(task);
+ goto err;
+ }
+ ns = nsp->mnt_ns;
+ get_mnt_ns(ns);
+ if (!task->real_fs) {
+ task_unlock(task);
+ put_task_struct(task);
+ ret = -ENOENT;
+ goto err_put_ns;
+ }
+ get_fs_root(task->real_fs, &root);
+ task_unlock(task);
+ put_task_struct(task);
+
+ ret = seq_open_private(file, &mounts_op, sizeof(struct proc_mounts));
+ if (ret)
+ goto err_put_path;
+
+ m = file->private_data;
+ m->poll_event = ns->event;
+
+ p = m->private;
+ p->ns = ns;
+ p->root = root;
+ p->show = show;
+
+ return 0;
+
+ err_put_path:
+ path_put(&root);
+ err_put_ns:
+ put_mnt_ns(ns);
+ err:
+ return ret;
+}
+
+static int mounts_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *m = file->private_data;
+ struct proc_mounts *p = m->private;
+ path_put(&p->root);
+ put_mnt_ns(p->ns);
+ return seq_release_private(inode, file);
+}
+
+static int mounts_open(struct inode *inode, struct file *file)
+{
+ return mounts_open_common(inode, file, show_vfsmnt);
+}
+
+static int mountinfo_open(struct inode *inode, struct file *file)
+{
+ return mounts_open_common(inode, file, show_mountinfo);
+}
+
+static int mountstats_open(struct inode *inode, struct file *file)
+{
+ return mounts_open_common(inode, file, show_vfsstat);
+}
+
+const struct file_operations proc_mounts_operations = {
+ .open = mounts_open,
+ .read_iter = seq_read_iter,
+ .splice_read = copy_splice_read,
+ .llseek = seq_lseek,
+ .release = mounts_release,
+ .poll = mounts_poll,
+};
+
+const struct file_operations proc_mountinfo_operations = {
+ .open = mountinfo_open,
+ .read_iter = seq_read_iter,
+ .splice_read = copy_splice_read,
+ .llseek = seq_lseek,
+ .release = mounts_release,
+ .poll = mounts_poll,
+};
+
+const struct file_operations proc_mountstats_operations = {
+ .open = mountstats_open,
+ .read_iter = seq_read_iter,
+ .splice_read = copy_splice_read,
+ .llseek = seq_lseek,
+ .release = mounts_release,
+};