1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/kernel.h>
  3#include <linux/errno.h>
  4#include <linux/fs.h>
  5#include <linux/file.h>
  6#include <linux/proc_fs.h>
  7#include <linux/seq_file.h>
  8#include <linux/io_uring.h>
  9
 10#include <uapi/linux/io_uring.h>
 11
 12#include "io_uring.h"
 13#include "sqpoll.h"
 14#include "fdinfo.h"
 15#include "cancel.h"
 16#include "rsrc.h"
 17
 18#ifdef CONFIG_PROC_FS
 19static __cold int io_uring_show_cred(struct seq_file *m, unsigned int id,
 20		const struct cred *cred)
 21{
 22	struct user_namespace *uns = seq_user_ns(m);
 23	struct group_info *gi;
 24	kernel_cap_t cap;
 25	unsigned __capi;
 26	int g;
 27
 28	seq_printf(m, "%5d\n", id);
 29	seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
 30	seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
 31	seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
 32	seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
 33	seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
 34	seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
 35	seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
 36	seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
 37	seq_puts(m, "\n\tGroups:\t");
 38	gi = cred->group_info;
 39	for (g = 0; g < gi->ngroups; g++) {
 40		seq_put_decimal_ull(m, g ? " " : "",
 41					from_kgid_munged(uns, gi->gid[g]));
 42	}
 43	seq_puts(m, "\n\tCapEff:\t");
 44	cap = cred->cap_effective;
 45	CAP_FOR_EACH_U32(__capi)
 46		seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
 47	seq_putc(m, '\n');
 48	return 0;
 49}
 50
 51static __cold void __io_uring_show_fdinfo(struct io_ring_ctx *ctx,
 52					  struct seq_file *m)
 53{
 54	struct io_sq_data *sq = NULL;
 55	struct io_overflow_cqe *ocqe;
 56	struct io_rings *r = ctx->rings;
 57	unsigned int sq_mask = ctx->sq_entries - 1, cq_mask = ctx->cq_entries - 1;
 58	unsigned int sq_head = READ_ONCE(r->sq.head);
 59	unsigned int sq_tail = READ_ONCE(r->sq.tail);
 60	unsigned int cq_head = READ_ONCE(r->cq.head);
 61	unsigned int cq_tail = READ_ONCE(r->cq.tail);
 62	unsigned int cq_shift = 0;
 63	unsigned int sq_shift = 0;
 64	unsigned int sq_entries, cq_entries;
 65	bool has_lock;
 66	unsigned int i;
 67
 68	if (ctx->flags & IORING_SETUP_CQE32)
 69		cq_shift = 1;
 70	if (ctx->flags & IORING_SETUP_SQE128)
 71		sq_shift = 1;
 72
 73	/*
 74	 * we may get imprecise sqe and cqe info if uring is actively running
 75	 * since we get cached_sq_head and cached_cq_tail without uring_lock
 76	 * and sq_tail and cq_head are changed by userspace. But it's ok since
 77	 * we usually use these info when it is stuck.
 78	 */
 79	seq_printf(m, "SqMask:\t0x%x\n", sq_mask);
 80	seq_printf(m, "SqHead:\t%u\n", sq_head);
 81	seq_printf(m, "SqTail:\t%u\n", sq_tail);
 82	seq_printf(m, "CachedSqHead:\t%u\n", ctx->cached_sq_head);
 83	seq_printf(m, "CqMask:\t0x%x\n", cq_mask);
 84	seq_printf(m, "CqHead:\t%u\n", cq_head);
 85	seq_printf(m, "CqTail:\t%u\n", cq_tail);
 86	seq_printf(m, "CachedCqTail:\t%u\n", ctx->cached_cq_tail);
 87	seq_printf(m, "SQEs:\t%u\n", sq_tail - sq_head);
 88	sq_entries = min(sq_tail - sq_head, ctx->sq_entries);
 89	for (i = 0; i < sq_entries; i++) {
 90		unsigned int entry = i + sq_head;
 91		struct io_uring_sqe *sqe;
 92		unsigned int sq_idx;
 93
 94		sq_idx = READ_ONCE(ctx->sq_array[entry & sq_mask]);
 95		if (sq_idx > sq_mask)
 96			continue;
 97		sqe = &ctx->sq_sqes[sq_idx << sq_shift];
 98		seq_printf(m, "%5u: opcode:%s, fd:%d, flags:%x, off:%llu, "
 99			      "addr:0x%llx, rw_flags:0x%x, buf_index:%d "
100			      "user_data:%llu",
101			   sq_idx, io_uring_get_opcode(sqe->opcode), sqe->fd,
102			   sqe->flags, (unsigned long long) sqe->off,
103			   (unsigned long long) sqe->addr, sqe->rw_flags,
104			   sqe->buf_index, sqe->user_data);
105		if (sq_shift) {
106			u64 *sqeb = (void *) (sqe + 1);
107			int size = sizeof(struct io_uring_sqe) / sizeof(u64);
108			int j;
109
110			for (j = 0; j < size; j++) {
111				seq_printf(m, ", e%d:0x%llx", j,
112						(unsigned long long) *sqeb);
113				sqeb++;
114			}
115		}
116		seq_printf(m, "\n");
117	}
118	seq_printf(m, "CQEs:\t%u\n", cq_tail - cq_head);
119	cq_entries = min(cq_tail - cq_head, ctx->cq_entries);
120	for (i = 0; i < cq_entries; i++) {
121		unsigned int entry = i + cq_head;
122		struct io_uring_cqe *cqe = &r->cqes[(entry & cq_mask) << cq_shift];
123
124		seq_printf(m, "%5u: user_data:%llu, res:%d, flag:%x",
125			   entry & cq_mask, cqe->user_data, cqe->res,
126			   cqe->flags);
127		if (cq_shift)
128			seq_printf(m, ", extra1:%llu, extra2:%llu\n",
129					cqe->big_cqe[0], cqe->big_cqe[1]);
130		seq_printf(m, "\n");
131	}
132
133	/*
134	 * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
135	 * since fdinfo case grabs it in the opposite direction of normal use
136	 * cases. If we fail to get the lock, we just don't iterate any
137	 * structures that could be going away outside the io_uring mutex.
138	 */
139	has_lock = mutex_trylock(&ctx->uring_lock);
140
141	if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
142		sq = ctx->sq_data;
143		if (!sq->thread)
144			sq = NULL;
145	}
146
147	seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
148	seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
149	seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
150	for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
151		struct file *f = io_file_from_index(&ctx->file_table, i);
152
153		if (f)
154			seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
155		else
156			seq_printf(m, "%5u: <none>\n", i);
157	}
158	seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
159	for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
160		struct io_mapped_ubuf *buf = ctx->user_bufs[i];
161		unsigned int len = buf->ubuf_end - buf->ubuf;
162
163		seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, len);
164	}
165	if (has_lock && !xa_empty(&ctx->personalities)) {
166		unsigned long index;
167		const struct cred *cred;
168
169		seq_printf(m, "Personalities:\n");
170		xa_for_each(&ctx->personalities, index, cred)
171			io_uring_show_cred(m, index, cred);
172	}
173
174	seq_puts(m, "PollList:\n");
175	for (i = 0; i < (1U << ctx->cancel_table.hash_bits); i++) {
176		struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
177		struct io_hash_bucket *hbl = &ctx->cancel_table_locked.hbs[i];
178		struct io_kiocb *req;
179
180		spin_lock(&hb->lock);
181		hlist_for_each_entry(req, &hb->list, hash_node)
182			seq_printf(m, "  op=%d, task_works=%d\n", req->opcode,
183					task_work_pending(req->task));
184		spin_unlock(&hb->lock);
185
186		if (!has_lock)
187			continue;
188		hlist_for_each_entry(req, &hbl->list, hash_node)
189			seq_printf(m, "  op=%d, task_works=%d\n", req->opcode,
190					task_work_pending(req->task));
191	}
192
193	if (has_lock)
194		mutex_unlock(&ctx->uring_lock);
195
196	seq_puts(m, "CqOverflowList:\n");
197	spin_lock(&ctx->completion_lock);
198	list_for_each_entry(ocqe, &ctx->cq_overflow_list, list) {
199		struct io_uring_cqe *cqe = &ocqe->cqe;
200
201		seq_printf(m, "  user_data=%llu, res=%d, flags=%x\n",
202			   cqe->user_data, cqe->res, cqe->flags);
203
204	}
205
206	spin_unlock(&ctx->completion_lock);
207}
208
209__cold void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
210{
211	struct io_ring_ctx *ctx = f->private_data;
212
213	if (percpu_ref_tryget(&ctx->refs)) {
214		__io_uring_show_fdinfo(ctx, m);
215		percpu_ref_put(&ctx->refs);
216	}
217}
218#endif