diff options
author | Eric W. Biederman <ebiederm@xmission.com> | 2020-02-19 10:37:15 -0600 |
---|---|---|
committer | Eric W. Biederman <ebiederm@xmission.com> | 2020-02-28 12:04:33 -0600 |
commit | 76313c70c52f930af4afd21684509ca52297ea71 (patch) | |
tree | 831848faa7388eb7b7cc5e0c03cfbfff1d9f724d | |
parent | af1abab986b85fdeb3e98c037988cfa4bf9d4018 (diff) | |
download | linux-76313c70c52f930af4afd21684509ca52297ea71.tar.bz2 |
uml: Create a private mount of proc for mconsole
The mconsole code only ever accesses proc for the initial pid
namespace. Instead of depending upon the proc_mnt which is
for proc_flush_task have uml create it's own mount of proc
instead.
This allows proc_flush_task to evolve and remove the
need for having a proc_mnt to do it's job.
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
-rw-r--r-- | arch/um/drivers/mconsole_kern.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c index e8f5c81c2c6c..30575bd92975 100644 --- a/arch/um/drivers/mconsole_kern.c +++ b/arch/um/drivers/mconsole_kern.c @@ -36,6 +36,8 @@ #include "mconsole_kern.h" #include <os.h> +static struct vfsmount *proc_mnt = NULL; + static int do_unlink_socket(struct notifier_block *notifier, unsigned long what, void *data) { @@ -123,7 +125,7 @@ void mconsole_log(struct mc_request *req) void mconsole_proc(struct mc_request *req) { - struct vfsmount *mnt = init_pid_ns.proc_mnt; + struct vfsmount *mnt = proc_mnt; char *buf; int len; struct file *file; @@ -134,6 +136,10 @@ void mconsole_proc(struct mc_request *req) ptr += strlen("proc"); ptr = skip_spaces(ptr); + if (!mnt) { + mconsole_reply(req, "Proc not available", 1, 0); + goto out; + } file = file_open_root(mnt->mnt_root, mnt, ptr, O_RDONLY, 0); if (IS_ERR(file)) { mconsole_reply(req, "Failed to open file", 1, 0); @@ -683,6 +689,24 @@ void mconsole_stack(struct mc_request *req) with_console(req, stack_proc, to); } +static int __init mount_proc(void) +{ + struct file_system_type *proc_fs_type; + struct vfsmount *mnt; + + proc_fs_type = get_fs_type("proc"); + if (!proc_fs_type) + return -ENODEV; + + mnt = kern_mount(proc_fs_type); + put_filesystem(proc_fs_type); + if (IS_ERR(mnt)) + return PTR_ERR(mnt); + + proc_mnt = mnt; + return 0; +} + /* * Changed by mconsole_setup, which is __setup, and called before SMP is * active. @@ -696,6 +720,8 @@ static int __init mconsole_init(void) int err; char file[UNIX_PATH_MAX]; + mount_proc(); + if (umid_file_name("mconsole", file, sizeof(file))) return -1; snprintf(mconsole_socket_name, sizeof(file), "%s", file); |