diff options
| -rw-r--r-- | arch/um/drivers/mconsole_kern.c | 49 |
1 files changed, 18 insertions, 31 deletions
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c index 5106924..3b3c366 100644 --- a/arch/um/drivers/mconsole_kern.c +++ b/arch/um/drivers/mconsole_kern.c @@ -125,50 +125,36 @@ void mconsole_log(struct mc_request *req) void mconsole_proc(struct mc_request *req) { struct nameidata nd; - struct file_system_type *proc; - struct super_block *super; + struct vfsmount *mnt = current->nsproxy->pid_ns->proc_mnt; struct file *file; int n, err; char *ptr = req->request.data, *buf; + mm_segment_t old_fs = get_fs(); ptr += strlen("proc"); ptr = skip_spaces(ptr); - proc = get_fs_type("proc"); - if (proc == NULL) { - mconsole_reply(req, "procfs not registered", 1, 0); + err = vfs_path_lookup(mnt->mnt_root, mnt, ptr, LOOKUP_FOLLOW, &nd); + if (err) { + mconsole_reply(req, "Failed to look up file", 1, 0); goto out; } - super = (*proc->get_sb)(proc, 0, NULL, NULL); - put_filesystem(proc); - if (super == NULL) { - mconsole_reply(req, "Failed to get procfs superblock", 1, 0); + err = may_open(&nd.path, MAY_READ, FMODE_READ); + if (result) { + mconsole_reply(req, "Failed to open file", 1, 0); + path_put(&nd.path); goto out; } - up_write(&super->s_umount); - - nd.path.dentry = super->s_root; - nd.path.mnt = NULL; - nd.flags = O_RDONLY + 1; - nd.last_type = LAST_ROOT; - - /* START: it was experienced that the stability problems are closed - * if commenting out these two calls + the below read cycle. To - * make UML crash again, it was enough to readd either one.*/ - err = link_path_walk(ptr, &nd); - if (err) { - mconsole_reply(req, "Failed to look up file", 1, 0); - goto out_kill; - } file = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY, current_cred()); + err = PTR_ERR(file); if (IS_ERR(file)) { mconsole_reply(req, "Failed to open file", 1, 0); - goto out_kill; + path_put(&nd.path); + goto out; } - /*END*/ buf = kmalloc(PAGE_SIZE, GFP_KERNEL); if (buf == NULL) { @@ -176,10 +162,13 @@ void mconsole_proc(struct mc_request *req) goto out_fput; } - if ((file->f_op != NULL) && (file->f_op->read != NULL)) { + if (file->f_op->read) { do { - n = (*file->f_op->read)(file, buf, PAGE_SIZE - 1, - &file->f_pos); + loff_t pos; + set_fs(KERNEL_DS); + n = vfs_read(file, buf, PAGE_SIZE - 1, &pos); + file_pos_write(file, pos); + set_fs(old_fs); if (n >= 0) { buf[n] = '\0'; mconsole_reply(req, buf, 0, (n > 0)); @@ -197,8 +186,6 @@ void mconsole_proc(struct mc_request *req) kfree(buf); out_fput: fput(file); - out_kill: - deactivate_super(super); out: ; } #endif |
