From: Alexey Gladkov <gladkov.alexey@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>,
Kernel Hardening <kernel-hardening@lists.openwall.com>,
Linux API <linux-api@vger.kernel.org>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>,
Linux Security Module <linux-security-module@vger.kernel.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Alexey Dobriyan <adobriyan@gmail.com>,
Alexey Gladkov <gladkov.alexey@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>,
Daniel Micay <danielmicay@gmail.com>,
Djalal Harouni <tixxdz@gmail.com>,
"Dmitry V . Levin" <ldv@altlinux.org>,
"Eric W . Biederman" <ebiederm@xmission.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ingo Molnar <mingo@kernel.org>,
"J . Bruce Fields" <bfields@fieldses.org>,
Jeff Layton <jlayton@poochiereds.net>,
Jonathan Corbet <corbet@lwn.net>,
Kees Cook <keescook@chromium.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Oleg Nesterov <oleg@redhat.com>,
Solar Designer <solar@openwall.com>,
Stephen Rothwell <sfr@canb.auug.org.au>
Subject: [PATCH v7 03/11] proc: move /proc/{self|thread-self} dentries to proc_fs_info
Date: Sat, 25 Jan 2020 14:05:33 +0100 [thread overview]
Message-ID: <20200125130541.450409-4-gladkov.alexey@gmail.com> (raw)
In-Reply-To: <20200125130541.450409-1-gladkov.alexey@gmail.com>
This is a preparation patch that moves /proc/{self|thread-self} dentries
to be stored inside procfs fs_info struct instead of making them per pid
namespace. Since we want to support multiple procfs instances we need to
make sure that these dentries are also per-superblock instead of
per-pidns, unmounting a private procfs won't clash with other procfs
mounts.
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Djalal Harouni <tixxdz@gmail.com>
Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
---
fs/proc/base.c | 5 +++--
fs/proc/root.c | 8 ++++----
fs/proc/self.c | 4 ++--
fs/proc/thread_self.c | 6 +++---
include/linux/pid_namespace.h | 4 +---
include/linux/proc_fs.h | 2 ++
6 files changed, 15 insertions(+), 14 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 672e71c52dbd..1eb366ad8b06 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -3316,6 +3316,7 @@ static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter ite
int proc_pid_readdir(struct file *file, struct dir_context *ctx)
{
struct tgid_iter iter;
+ struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
struct pid_namespace *ns = proc_pid_ns(file_inode(file));
loff_t pos = ctx->pos;
@@ -3323,13 +3324,13 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx)
return 0;
if (pos == TGID_OFFSET - 2) {
- struct inode *inode = d_inode(ns->proc_self);
+ struct inode *inode = d_inode(fs_info->proc_self);
if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
return 0;
ctx->pos = pos = pos + 1;
}
if (pos == TGID_OFFSET - 1) {
- struct inode *inode = d_inode(ns->proc_thread_self);
+ struct inode *inode = d_inode(fs_info->proc_thread_self);
if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
return 0;
ctx->pos = pos = pos + 1;
diff --git a/fs/proc/root.c b/fs/proc/root.c
index d449f095f0f7..637e26cc795e 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -210,10 +210,10 @@ static void proc_kill_sb(struct super_block *sb)
{
struct proc_fs_info *fs_info = proc_sb_info(sb);
- if (fs_info->pid_ns->proc_self)
- dput(fs_info->pid_ns->proc_self);
- if (fs_info->pid_ns->proc_thread_self)
- dput(fs_info->pid_ns->proc_thread_self);
+ if (fs_info->proc_self)
+ dput(fs_info->proc_self);
+ if (fs_info->proc_thread_self)
+ dput(fs_info->proc_thread_self);
kill_anon_super(sb);
put_pid_ns(fs_info->pid_ns);
kfree(fs_info);
diff --git a/fs/proc/self.c b/fs/proc/self.c
index 57c0a1047250..846fc2b7c8a8 100644
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -36,7 +36,7 @@ static unsigned self_inum __ro_after_init;
int proc_setup_self(struct super_block *s)
{
struct inode *root_inode = d_inode(s->s_root);
- struct pid_namespace *ns = proc_pid_ns(root_inode);
+ struct proc_fs_info *fs_info = proc_sb_info(s);
struct dentry *self;
int ret = -ENOMEM;
@@ -62,7 +62,7 @@ int proc_setup_self(struct super_block *s)
if (ret)
pr_err("proc_fill_super: can't allocate /proc/self\n");
else
- ns->proc_self = self;
+ fs_info->proc_self = self;
return ret;
}
diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c
index f61ae53533f5..2493cbbdfa6f 100644
--- a/fs/proc/thread_self.c
+++ b/fs/proc/thread_self.c
@@ -36,7 +36,7 @@ static unsigned thread_self_inum __ro_after_init;
int proc_setup_thread_self(struct super_block *s)
{
struct inode *root_inode = d_inode(s->s_root);
- struct pid_namespace *ns = proc_pid_ns(root_inode);
+ struct proc_fs_info *fs_info = proc_sb_info(s);
struct dentry *thread_self;
int ret = -ENOMEM;
@@ -60,9 +60,9 @@ int proc_setup_thread_self(struct super_block *s)
inode_unlock(root_inode);
if (ret)
- pr_err("proc_fill_super: can't allocate /proc/thread_self\n");
+ pr_err("proc_fill_super: can't allocate /proc/thread-self\n");
else
- ns->proc_thread_self = thread_self;
+ fs_info->proc_thread_self = thread_self;
return ret;
}
diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h
index 49538b172483..f91a8bf6e09e 100644
--- a/include/linux/pid_namespace.h
+++ b/include/linux/pid_namespace.h
@@ -31,9 +31,7 @@ struct pid_namespace {
unsigned int level;
struct pid_namespace *parent;
#ifdef CONFIG_PROC_FS
- struct vfsmount *proc_mnt;
- struct dentry *proc_self;
- struct dentry *proc_thread_self;
+ struct vfsmount *proc_mnt; /* Internal proc mounted during each new pidns */
#endif
#ifdef CONFIG_BSD_PROCESS_ACCT
struct fs_pin *bacct;
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 2d79489e55aa..59162988998e 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -14,6 +14,8 @@ struct seq_operations;
struct proc_fs_info {
struct pid_namespace *pid_ns;
+ struct dentry *proc_self; /* For /proc/self */
+ struct dentry *proc_thread_self; /* For /proc/thread-self */
};
static inline struct proc_fs_info *proc_sb_info(struct super_block *sb)
--
2.24.1
next prev parent reply other threads:[~2020-01-25 13:07 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-25 13:05 [PATCH v7 00/11] proc: modernize proc to support multiple private instances Alexey Gladkov
2020-01-25 13:05 ` [PATCH v7 01/11] proc: Rename struct proc_fs_info to proc_fs_opts Alexey Gladkov
2020-01-25 13:05 ` [PATCH v7 02/11] proc: add proc_fs_info struct to store proc information Alexey Gladkov
2020-01-28 13:43 ` Oleg Nesterov
2020-01-28 14:58 ` Oleg Nesterov
2020-01-25 13:05 ` Alexey Gladkov [this message]
2020-01-25 13:05 ` [PATCH v7 04/11] proc: move hide_pid, pid_gid from pid_namespace to proc_fs_info Alexey Gladkov
2020-01-25 13:05 ` [PATCH v7 05/11] proc: add helpers to set and get proc hidepid and gid mount options Alexey Gladkov
2020-01-25 13:05 ` [PATCH v7 06/11] proc: support mounting procfs instances inside same pid namespace Alexey Gladkov
2020-01-25 13:05 ` [PATCH v7 07/11] proc: flush task dcache entries from all procfs instances Alexey Gladkov
2020-01-25 18:45 ` Linus Torvalds
2020-01-27 23:23 ` Alexey Gladkov
2020-01-25 13:05 ` [PATCH v7 08/11] proc: instantiate only pids that we can ptrace on 'hidepid=4' mount option Alexey Gladkov
2020-01-25 13:05 ` [PATCH v7 09/11] proc: add option to mount only a pids subset Alexey Gladkov
2020-01-25 13:05 ` [PATCH v7 10/11] docs: proc: add documentation for "hidepid=4" and "subset=pidfs" options and new mount behavior Alexey Gladkov
2020-01-25 13:05 ` [PATCH v7 11/11] proc: Move hidepid values to uapi as they are user interface to mount Alexey Gladkov
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