fdinfo.c

  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/nospec.h>
  9#include <linux/io_uring.h>
 10
 11#include <uapi/linux/io_uring.h>
 12
 13#include "filetable.h"
 14#include "sqpoll.h"
 15#include "fdinfo.h"
 16#include "cancel.h"
 17#include "rsrc.h"
 18#include "opdef.h"
 19
 20#ifdef CONFIG_NET_RX_BUSY_POLL
 21static __cold void common_tracking_show_fdinfo(struct io_ring_ctx *ctx,
 22					       struct seq_file *m,
 23					       const char *tracking_strategy)
 24{
 25	seq_puts(m, "NAPI:\tenabled\n");
 26	seq_printf(m, "napi tracking:\t%s\n", tracking_strategy);
 27	seq_printf(m, "napi_busy_poll_dt:\t%llu\n", ctx->napi_busy_poll_dt);
 28	if (ctx->napi_prefer_busy_poll)
 29		seq_puts(m, "napi_prefer_busy_poll:\ttrue\n");
 30	else
 31		seq_puts(m, "napi_prefer_busy_poll:\tfalse\n");
 32}
 33
 34static __cold void napi_show_fdinfo(struct io_ring_ctx *ctx,
 35				    struct seq_file *m)
 36{
 37	unsigned int mode = READ_ONCE(ctx->napi_track_mode);
 38
 39	switch (mode) {
 40	case IO_URING_NAPI_TRACKING_INACTIVE:
 41		seq_puts(m, "NAPI:\tdisabled\n");
 42		break;
 43	case IO_URING_NAPI_TRACKING_DYNAMIC:
 44		common_tracking_show_fdinfo(ctx, m, "dynamic");
 45		break;
 46	case IO_URING_NAPI_TRACKING_STATIC:
 47		common_tracking_show_fdinfo(ctx, m, "static");
 48		break;
 49	default:
 50		seq_printf(m, "NAPI:\tunknown mode (%u)\n", mode);
 51	}
 52}
 53#else
 54static inline void napi_show_fdinfo(struct io_ring_ctx *ctx,
 55				    struct seq_file *m)
 56{
 57}
 58#endif
 59
 60static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
 61{
 62	struct io_overflow_cqe *ocqe;
 63	struct io_rings *r = ctx->rings;
 64	unsigned int sq_mask = ctx->sq_entries - 1, cq_mask = ctx->cq_entries - 1;
 65	unsigned int sq_head = READ_ONCE(r->sq.head);
 66	unsigned int sq_tail = READ_ONCE(r->sq.tail);
 67	unsigned int cq_head = READ_ONCE(r->cq.head);
 68	unsigned int cq_tail = READ_ONCE(r->cq.tail);
 69	unsigned int sq_shift = 0;
 70	unsigned int cq_entries, sq_entries;
 71	int sq_pid = -1, sq_cpu = -1;
 72	u64 sq_total_time = 0, sq_work_time = 0;
 73	unsigned int i;
 74
 75	if (ctx->flags & IORING_SETUP_SQE128)
 76		sq_shift = 1;
 77
 78	/*
 79	 * we may get imprecise sqe and cqe info if uring is actively running
 80	 * since we get cached_sq_head and cached_cq_tail without uring_lock
 81	 * and sq_tail and cq_head are changed by userspace. But it's ok since
 82	 * we usually use these info when it is stuck.
 83	 */
 84	seq_printf(m, "SqMask:\t0x%x\n", sq_mask);
 85	seq_printf(m, "SqHead:\t%u\n", sq_head);
 86	seq_printf(m, "SqTail:\t%u\n", sq_tail);
 87	seq_printf(m, "CachedSqHead:\t%u\n", data_race(ctx->cached_sq_head));
 88	seq_printf(m, "CqMask:\t0x%x\n", cq_mask);
 89	seq_printf(m, "CqHead:\t%u\n", cq_head);
 90	seq_printf(m, "CqTail:\t%u\n", cq_tail);
 91	seq_printf(m, "CachedCqTail:\t%u\n", data_race(ctx->cached_cq_tail));
 92	seq_printf(m, "SQEs:\t%u\n", sq_tail - sq_head);
 93	sq_entries = min(sq_tail - sq_head, ctx->sq_entries);
 94	for (i = 0; i < sq_entries; i++) {
 95		unsigned int entry = i + sq_head;
 96		struct io_uring_sqe *sqe;
 97		unsigned int sq_idx;
 98		bool sqe128 = false;
 99		u8 opcode;
100
101		if (ctx->flags & IORING_SETUP_NO_SQARRAY)
102			sq_idx = entry & sq_mask;
103		else
104			sq_idx = READ_ONCE(ctx->sq_array[entry & sq_mask]);
105		if (sq_idx > sq_mask)
106			continue;
107
108		sqe = &ctx->sq_sqes[sq_idx << sq_shift];
109		opcode = READ_ONCE(sqe->opcode);
110		if (opcode >= IORING_OP_LAST)
111			continue;
112		opcode = array_index_nospec(opcode, IORING_OP_LAST);
113		if (sq_shift) {
114			sqe128 = true;
115		} else if (io_issue_defs[opcode].is_128) {
116			if (!(ctx->flags & IORING_SETUP_SQE_MIXED)) {
117				seq_printf(m,
118					"%5u: invalid sqe, 128B entry on non-mixed sq\n",
119					sq_idx);
120				break;
121			}
122			if (sq_idx == sq_mask) {
123				seq_printf(m,
124					"%5u: corrupted sqe, wrapping 128B entry\n",
125					sq_idx);
126				break;
127			}
128			sq_head++;
129			i++;
130			sqe128 = true;
131		}
132		seq_printf(m, "%5u: opcode:%s, fd:%d, flags:%x, off:%llu, "
133			      "addr:0x%llx, rw_flags:0x%x, buf_index:%d "
134			      "user_data:%llu",
135			   sq_idx, io_uring_get_opcode(opcode), sqe->fd,
136			   sqe->flags, (unsigned long long) sqe->off,
137			   (unsigned long long) sqe->addr, sqe->rw_flags,
138			   sqe->buf_index, sqe->user_data);
139		if (sqe128) {
140			u64 *sqeb = (void *) (sqe + 1);
141			int size = sizeof(struct io_uring_sqe) / sizeof(u64);
142			int j;
143
144			for (j = 0; j < size; j++) {
145				seq_printf(m, ", e%d:0x%llx", j,
146						(unsigned long long) *sqeb);
147				sqeb++;
148			}
149		}
150		seq_printf(m, "\n");
151		cond_resched();
152	}
153	seq_printf(m, "CQEs:\t%u\n", cq_tail - cq_head);
154	cq_entries = min(cq_tail - cq_head, ctx->cq_entries);
155	for (i = 0; i < cq_entries; i++) {
156		struct io_uring_cqe *cqe;
157		bool cqe32 = false;
158
159		cqe = &r->cqes[(cq_head & cq_mask)];
160		if (cqe->flags & IORING_CQE_F_32 || ctx->flags & IORING_SETUP_CQE32)
161			cqe32 = true;
162		seq_printf(m, "%5u: user_data:%llu, res:%d, flags:%x",
163			   cq_head & cq_mask, cqe->user_data, cqe->res,
164			   cqe->flags);
165		if (cqe32)
166			seq_printf(m, ", extra1:%llu, extra2:%llu",
167					cqe->big_cqe[0], cqe->big_cqe[1]);
168		seq_printf(m, "\n");
169		cq_head++;
170		if (cqe32) {
171			cq_head++;
172			i++;
173		}
174		cond_resched();
175	}
176
177	if (ctx->flags & IORING_SETUP_SQPOLL) {
178		struct io_sq_data *sq = ctx->sq_data;
179		struct task_struct *tsk;
180
181		rcu_read_lock();
182		tsk = rcu_dereference(sq->thread);
183		/*
184		 * sq->thread might be NULL if we raced with the sqpoll
185		 * thread termination.
186		 */
187		if (tsk) {
188			u64 usec;
189
190			get_task_struct(tsk);
191			rcu_read_unlock();
192			usec = io_sq_cpu_usec(tsk);
193			put_task_struct(tsk);
194			sq_pid = sq->task_pid;
195			sq_cpu = sq->sq_cpu;
196			sq_total_time = usec;
197			sq_work_time = sq->work_time;
198		} else {
199			rcu_read_unlock();
200		}
201	}
202
203	seq_printf(m, "SqThread:\t%d\n", sq_pid);
204	seq_printf(m, "SqThreadCpu:\t%d\n", sq_cpu);
205	seq_printf(m, "SqTotalTime:\t%llu\n", sq_total_time);
206	seq_printf(m, "SqWorkTime:\t%llu\n", sq_work_time);
207	seq_printf(m, "UserFiles:\t%u\n", ctx->file_table.data.nr);
208	for (i = 0; i < ctx->file_table.data.nr; i++) {
209		struct file *f = NULL;
210
211		if (ctx->file_table.data.nodes[i])
212			f = io_slot_file(ctx->file_table.data.nodes[i]);
213		if (f) {
214			seq_printf(m, "%5u: ", i);
215			seq_file_path(m, f, " \t\n\\");
216			seq_puts(m, "\n");
217		}
218	}
219	seq_printf(m, "UserBufs:\t%u\n", ctx->buf_table.nr);
220	for (i = 0; i < ctx->buf_table.nr; i++) {
221		struct io_mapped_ubuf *buf = NULL;
222
223		if (ctx->buf_table.nodes[i])
224			buf = ctx->buf_table.nodes[i]->buf;
225		if (buf)
226			seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, buf->len);
227		else
228			seq_printf(m, "%5u: <none>\n", i);
229	}
230
231	seq_puts(m, "PollList:\n");
232	for (i = 0; i < (1U << ctx->cancel_table.hash_bits); i++) {
233		struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
234		struct io_kiocb *req;
235
236		hlist_for_each_entry(req, &hb->list, hash_node)
237			seq_printf(m, "  op=%d, task_works=%d\n", req->opcode,
238					task_work_pending(req->tctx->task));
239	}
240
241	seq_puts(m, "CqOverflowList:\n");
242	spin_lock(&ctx->completion_lock);
243	list_for_each_entry(ocqe, &ctx->cq_overflow_list, list) {
244		struct io_uring_cqe *cqe = &ocqe->cqe;
245
246		seq_printf(m, "  user_data=%llu, res=%d, flags=%x\n",
247			   cqe->user_data, cqe->res, cqe->flags);
248
249	}
250	spin_unlock(&ctx->completion_lock);
251	napi_show_fdinfo(ctx, m);
252}
253
254/*
255 * Caller holds a reference to the file already, we don't need to do
256 * anything else to get an extra reference.
257 */
258__cold void io_uring_show_fdinfo(struct seq_file *m, struct file *file)
259{
260	struct io_ring_ctx *ctx = file->private_data;
261
262	/*
263	 * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
264	 * since fdinfo case grabs it in the opposite direction of normal use
265	 * cases.
266	 */
267	if (mutex_trylock(&ctx->uring_lock)) {
268		__io_uring_show_fdinfo(ctx, m);
269		mutex_unlock(&ctx->uring_lock);
270	}
271}