the-tree/io_uring/fdinfo.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <linux/kernel.h>
0003 #include <linux/errno.h>
0004 #include <linux/fs.h>
0005 #include <linux/file.h>
0006 #include <linux/proc_fs.h>
0007 #include <linux/seq_file.h>
0008 #include <linux/io_uring.h>
0009
0010 #include <uapi/linux/io_uring.h>
0011
0012 #include "io_uring.h"
0013 #include "sqpoll.h"
0014 #include "fdinfo.h"
0015 #include "cancel.h"
0016 #include "rsrc.h"
0017
0018 #ifdef CONFIG_PROC_FS
0019 static __cold int io_uring_show_cred(struct seq_file *m, unsigned int id,
0020         const struct cred *cred)
0021 {
0022     struct user_namespace *uns = seq_user_ns(m);
0023     struct group_info *gi;
0024     kernel_cap_t cap;
0025     unsigned __capi;
0026     int g;
0027
0028     seq_printf(m, "%5d\n", id);
0029     seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
0030     seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
0031     seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
0032     seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
0033     seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
0034     seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
0035     seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
0036     seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
0037     seq_puts(m, "\n\tGroups:\t");
0038     gi = cred->group_info;
0039     for (g = 0; g < gi->ngroups; g++) {
0040         seq_put_decimal_ull(m, g ? " " : "",
0041                     from_kgid_munged(uns, gi->gid[g]));
0042     }
0043     seq_puts(m, "\n\tCapEff:\t");
0044     cap = cred->cap_effective;
0045     CAP_FOR_EACH_U32(__capi)
0046         seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
0047     seq_putc(m, '\n');
0048     return 0;
0049 }
0050
0051 static __cold void __io_uring_show_fdinfo(struct io_ring_ctx *ctx,
0052                       struct seq_file *m)
0053 {
0054     struct io_sq_data *sq = NULL;
0055     struct io_overflow_cqe *ocqe;
0056     struct io_rings *r = ctx->rings;
0057     unsigned int sq_mask = ctx->sq_entries - 1, cq_mask = ctx->cq_entries - 1;
0058     unsigned int sq_head = READ_ONCE(r->sq.head);
0059     unsigned int sq_tail = READ_ONCE(r->sq.tail);
0060     unsigned int cq_head = READ_ONCE(r->cq.head);
0061     unsigned int cq_tail = READ_ONCE(r->cq.tail);
0062     unsigned int cq_shift = 0;
0063     unsigned int sq_entries, cq_entries;
0064     bool has_lock;
0065     bool is_cqe32 = (ctx->flags & IORING_SETUP_CQE32);
0066     unsigned int i;
0067
0068     if (is_cqe32)
0069         cq_shift = 1;
0070
0071     /*
0072      * we may get imprecise sqe and cqe info if uring is actively running
0073      * since we get cached_sq_head and cached_cq_tail without uring_lock
0074      * and sq_tail and cq_head are changed by userspace. But it's ok since
0075      * we usually use these info when it is stuck.
0076      */
0077     seq_printf(m, "SqMask:\t0x%x\n", sq_mask);
0078     seq_printf(m, "SqHead:\t%u\n", sq_head);
0079     seq_printf(m, "SqTail:\t%u\n", sq_tail);
0080     seq_printf(m, "CachedSqHead:\t%u\n", ctx->cached_sq_head);
0081     seq_printf(m, "CqMask:\t0x%x\n", cq_mask);
0082     seq_printf(m, "CqHead:\t%u\n", cq_head);
0083     seq_printf(m, "CqTail:\t%u\n", cq_tail);
0084     seq_printf(m, "CachedCqTail:\t%u\n", ctx->cached_cq_tail);
0085     seq_printf(m, "SQEs:\t%u\n", sq_tail - ctx->cached_sq_head);
0086     sq_entries = min(sq_tail - sq_head, ctx->sq_entries);
0087     for (i = 0; i < sq_entries; i++) {
0088         unsigned int entry = i + sq_head;
0089         unsigned int sq_idx = READ_ONCE(ctx->sq_array[entry & sq_mask]);
0090         struct io_uring_sqe *sqe;
0091
0092         if (sq_idx > sq_mask)
0093             continue;
0094         sqe = &ctx->sq_sqes[sq_idx];
0095         seq_printf(m, "%5u: opcode:%d, fd:%d, flags:%x, user_data:%llu\n",
0096                sq_idx, sqe->opcode, sqe->fd, sqe->flags,
0097                sqe->user_data);
0098     }
0099     seq_printf(m, "CQEs:\t%u\n", cq_tail - cq_head);
0100     cq_entries = min(cq_tail - cq_head, ctx->cq_entries);
0101     for (i = 0; i < cq_entries; i++) {
0102         unsigned int entry = i + cq_head;
0103         struct io_uring_cqe *cqe = &r->cqes[(entry & cq_mask) << cq_shift];
0104
0105         if (!is_cqe32) {
0106             seq_printf(m, "%5u: user_data:%llu, res:%d, flag:%x\n",
0107                entry & cq_mask, cqe->user_data, cqe->res,
0108                cqe->flags);
0109         } else {
0110             seq_printf(m, "%5u: user_data:%llu, res:%d, flag:%x, "
0111                 "extra1:%llu, extra2:%llu\n",
0112                 entry & cq_mask, cqe->user_data, cqe->res,
0113                 cqe->flags, cqe->big_cqe[0], cqe->big_cqe[1]);
0114         }
0115     }
0116
0117     /*
0118      * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
0119      * since fdinfo case grabs it in the opposite direction of normal use
0120      * cases. If we fail to get the lock, we just don't iterate any
0121      * structures that could be going away outside the io_uring mutex.
0122      */
0123     has_lock = mutex_trylock(&ctx->uring_lock);
0124
0125     if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
0126         sq = ctx->sq_data;
0127         if (!sq->thread)
0128             sq = NULL;
0129     }
0130
0131     seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
0132     seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
0133     seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
0134     for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
0135         struct file *f = io_file_from_index(&ctx->file_table, i);
0136
0137         if (f)
0138             seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
0139         else
0140             seq_printf(m, "%5u: <none>\n", i);
0141     }
0142     seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
0143     for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
0144         struct io_mapped_ubuf *buf = ctx->user_bufs[i];
0145         unsigned int len = buf->ubuf_end - buf->ubuf;
0146
0147         seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, len);
0148     }
0149     if (has_lock && !xa_empty(&ctx->personalities)) {
0150         unsigned long index;
0151         const struct cred *cred;
0152
0153         seq_printf(m, "Personalities:\n");
0154         xa_for_each(&ctx->personalities, index, cred)
0155             io_uring_show_cred(m, index, cred);
0156     }
0157     if (has_lock)
0158         mutex_unlock(&ctx->uring_lock);
0159
0160     seq_puts(m, "PollList:\n");
0161     for (i = 0; i < (1U << ctx->cancel_table.hash_bits); i++) {
0162         struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
0163         struct io_kiocb *req;
0164
0165         spin_lock(&hb->lock);
0166         hlist_for_each_entry(req, &hb->list, hash_node)
0167             seq_printf(m, "  op=%d, task_works=%d\n", req->opcode,
0168                     task_work_pending(req->task));
0169         spin_unlock(&hb->lock);
0170     }
0171
0172     seq_puts(m, "CqOverflowList:\n");
0173     spin_lock(&ctx->completion_lock);
0174     list_for_each_entry(ocqe, &ctx->cq_overflow_list, list) {
0175         struct io_uring_cqe *cqe = &ocqe->cqe;
0176
0177         seq_printf(m, "  user_data=%llu, res=%d, flags=%x\n",
0178                cqe->user_data, cqe->res, cqe->flags);
0179
0180     }
0181
0182     spin_unlock(&ctx->completion_lock);
0183 }
0184
0185 __cold void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
0186 {
0187     struct io_ring_ctx *ctx = f->private_data;
0188
0189     if (percpu_ref_tryget(&ctx->refs)) {
0190         __io_uring_show_fdinfo(ctx, m);
0191         percpu_ref_put(&ctx->refs);
0192     }
0193 }
0194 #endif