#include #include #include #include #include #include #include #include #include static struct vfsmount *nsfs_mnt; static long ns_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg); static const struct file_operations ns_file_operations = { .llseek = no_llseek, .unlocked_ioctl = ns_ioctl, }; static char *ns_dname(struct dentry *dentry, char *buffer, int buflen) { struct inode *inode = d_inode(dentry); const struct proc_ns_operations *ns_ops = dentry->d_fsdata; return dynamic_dname(dentry, buffer, buflen, "%s:[%lu]", ns_ops->name, inode->i_ino); } static void ns_prune_dentry(struct dentry *dentry) { struct inode *inode = d_inode(dentry); if (inode) { struct ns_common *ns = inode->i_private; atomic_long_set(&ns->stashed, 0); } } const struct dentry_operations ns_dentry_operations = { .d_prune = ns_prune_dentry, .d_delete = always_delete_dentry, .d_dname = ns_dname, }; static void nsfs_evict(struct inode *inode) { struct ns_common *ns = inode->i_private; clear_inode(inode); ns->ops->put(ns); } static void *__ns_get_path(struct path *path, struct ns_common *ns) { struct vfsmount *mnt = nsfs_mnt; struct qstr qname = { .name = "", }; struct dentry *dentry; struct inode *inode; unsigned long d; rcu_read_lock(); d = atomic_long_read(&ns->stashed); if (!d) goto slow; dentry = (struct dentry *)d; if (!lockref_get_not_dead(&dentry->d_lockref)) goto slow; rcu_read_unlock(); ns->ops->put(ns); got_it: path->mnt = mntget(mnt); path->dentry = dentry; return NULL; slow: rcu_read_unlock(); inode = new_inode_pseudo(mnt->mnt_sb); if (!inode) { ns->ops->put(ns); return ERR_PTR(-ENOMEM); } inode->i_ino = ns->inum; inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); inode->i_flags |= S_IMMUTABLE; inode->i_mode = S_IFREG | S_IRUGO; inode->i_fop = &ns_file_operations; inode->i_private = ns; dentry = d_alloc_pseudo(mnt->mnt_sb, &qname); if (!dentry) { iput(inode); return ERR_PTR(-ENOMEM); } d_instantiate(dentry, inode); dentry->d_fsdata = (void *)ns->ops; d = atomic_long_cmpxchg(&ns->stashed, 0, (unsigned long)dentry); if (d) { d_delete(dentry); /* make sure ->d_prune() does nothing */ dput(dentry); cpu_relax(); return ERR_PTR(-EAGAIN); } goto got_it; } void *ns_get_path(struct path *path, struct task_struct *task, const struct proc_ns_operations *ns_ops) { struct ns_common *ns; void *ret; again: ns = ns_ops->get(task); if (!ns) return ERR_PTR(-ENOENT); ret = __ns_get_path(path, ns); if (IS_ERR(ret) && PTR_ERR(ret) == -EAGAIN) goto again; return ret; } int open_related_ns(struct ns_common *ns, struct ns_common *(*get_ns)(struct ns_common *ns)) { struct path path = {}; struct file *f; void *err; int fd; fd = get_unused_fd_flags(O_CLOEXEC); if (fd < 0) return fd; while (1) { struct ns_common *relative; relative = get_ns(ns); if (IS_ERR(relative)) { put_unused_fd(fd); return PTR_ERR(relative); } err = __ns_get_path(&path, relative); if (IS_ERR(err) && PTR_ERR(err) == -EAGAIN) continue; break; } if (IS_ERR(err)) { put_unused_fd(fd); return PTR_ERR(err); } f = dentry_open(&path, O_RDONLY, current_cred()); path_put(&path); if (IS_ERR(f)) { put_unused_fd(fd); fd = PTR_ERR(f); } else fd_install(fd, f); return fd; } static long ns_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct ns_common *ns = get_proc_ns(file_inode(filp)); switch (ioctl) { case NS_GET_USERNS: return open_related_ns(ns, ns_get_owner); case NS_GET_PARENT: if (!ns->ops->get_parent) return -EINVAL; return open_related_ns(ns, ns->ops->get_parent); default: return -ENOTTY; } } int ns_get_name(char *buf, size_t size, struct task_struct *task, const struct proc_ns_operations *ns_ops) { struct ns_common *ns; int res = -ENOENT; ns = ns_ops->get(task); if (ns) { res = snprintf(buf, size, "%s:[%u]", ns_ops->name, ns->inum); ns_ops->put(ns); } return res; } struct file *proc_ns_fget(int fd) { struct file *file; file = fget(fd); if (!file) return ERR_PTR(-EBADF); if (file->f_op != &ns_file_operations) goto out_invalid; return file; out_invalid: fput(file); return ERR_PTR(-EINVAL); } static int nsfs_show_path(struct seq_file *seq, struct dentry *dentry) { struct inode *inode = d_inode(dentry); const struct proc_ns_operations *ns_ops = dentry->d_fsdata; seq_printf(seq, "%s:[%lu]", ns_ops->name, inode->i_ino); return 0; } static const struct super_operations nsfs_ops = { .statfs = simple_statfs, .evict_inode = nsfs_evict, .show_path = nsfs_show_path, }; static struct dentry *nsfs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { return mount_pseudo(fs_type, "nsfs:", &nsfs_ops, &ns_dentry_operations, NSFS_MAGIC); } static struct file_system_type nsfs = { .name = "nsfs", .mount = nsfs_mount, .kill_sb = kill_anon_super, }; void __init nsfs_init(void) { nsfs_mnt = kern_mount(&nsfs); if (IS_ERR(nsfs_mnt)) panic("can't set nsfs up\n"); nsfs_mnt->mnt_sb->s_flags &= ~MS_NOUSER; } it-info'> authorThomas Gleixner <tglx@linutronix.de>2017-01-31 23:58:38 +0100 committerIngo Molnar <mingo@kernel.org>2017-02-01 08:37:27 +0100 commitdd86e373e09fb16b83e8adf5c48c421a4ca76468 (patch) tree55703c2ea8584e303e342090614e0aab3509ab21 /tools/virtio/virtio-trace/trace-agent-ctl.c parent0b3589be9b98994ce3d5aeca52445d1f5627c4ba (diff)
perf/x86/intel/rapl: Make package handling more robust
The package management code in RAPL relies on package mapping being available before a CPU is started. This changed with: 9d85eb9119f4 ("x86/smpboot: Make logical package management more robust") because the ACPI/BIOS information turned out to be unreliable, but that left RAPL in broken state. This was not noticed because on a regular boot all CPUs are online before RAPL is initialized. A possible fix would be to reintroduce the mess which allocates a package data structure in CPU prepare and when it turns out to already exist in starting throw it away later in the CPU online callback. But that's a horrible hack and not required at all because RAPL becomes functional for perf only in the CPU online callback. That's correct because user space is not yet informed about the CPU being onlined, so nothing caan rely on RAPL being available on that particular CPU. Move the allocation to the CPU online callback and simplify the hotplug handling. At this point the package mapping is established and correct. This also adds a missing check for available package data in the event_init() function. Reported-by: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: 9d85eb9119f4 ("x86/smpboot: Make logical package management more robust") Link: http://lkml.kernel.org/r/20170131230141.212593966@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/virtio/virtio-trace/trace-agent-ctl.c')