io_uring/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/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
  19 static __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
  51 static __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_entries, cq_entries;
  64         bool has_lock;
  65         bool is_cqe32 = (ctx->flags & IORING_SETUP_CQE32);
  66         unsigned int i;
  67
  68         if (is_cqe32)
  69                 cq_shift = 1;
  70
  71         /*
  72          * we may get imprecise sqe and cqe info if uring is actively running
  73          * since we get cached_sq_head and cached_cq_tail without uring_lock
  74          * and sq_tail and cq_head are changed by userspace. But it's ok since
  75          * we usually use these info when it is stuck.
  76          */
  77         seq_printf(m, "SqMask:\t0x%x\n", sq_mask);
  78         seq_printf(m, "SqHead:\t%u\n", sq_head);
  79         seq_printf(m, "SqTail:\t%u\n", sq_tail);
  80         seq_printf(m, "CachedSqHead:\t%u\n", ctx->cached_sq_head);
  81         seq_printf(m, "CqMask:\t0x%x\n", cq_mask);
  82         seq_printf(m, "CqHead:\t%u\n", cq_head);
  83         seq_printf(m, "CqTail:\t%u\n", cq_tail);
  84         seq_printf(m, "CachedCqTail:\t%u\n", ctx->cached_cq_tail);
  85         seq_printf(m, "SQEs:\t%u\n", sq_tail - ctx->cached_sq_head);
  86         sq_entries = min(sq_tail - sq_head, ctx->sq_entries);
  87         for (i = 0; i < sq_entries; i++) {
  88                 unsigned int entry = i + sq_head;
  89                 unsigned int sq_idx = READ_ONCE(ctx->sq_array[entry & sq_mask]);
  90                 struct io_uring_sqe *sqe;
  91
  92                 if (sq_idx > sq_mask)
  93                         continue;
  94                 sqe = &ctx->sq_sqes[sq_idx];
  95                 seq_printf(m, "%5u: opcode:%d, fd:%d, flags:%x, user_data:%llu\n",
  96                            sq_idx, sqe->opcode, sqe->fd, sqe->flags,
  97                            sqe->user_data);
  98         }
  99         seq_printf(m, "CQEs:\t%u\n", cq_tail - cq_head);
 100         cq_entries = min(cq_tail - cq_head, ctx->cq_entries);
 101         for (i = 0; i < cq_entries; i++) {
 102                 unsigned int entry = i + cq_head;
 103                 struct io_uring_cqe *cqe = &r->cqes[(entry & cq_mask) << cq_shift];
 104
 105                 if (!is_cqe32) {
 106                         seq_printf(m, "%5u: user_data:%llu, res:%d, flag:%x\n",
 107                            entry & cq_mask, cqe->user_data, cqe->res,
 108                            cqe->flags);
 109                 } else {
 110                         seq_printf(m, "%5u: user_data:%llu, res:%d, flag:%x, "
 111                                 "extra1:%llu, extra2:%llu\n",
 112                                 entry & cq_mask, cqe->user_data, cqe->res,
 113                                 cqe->flags, cqe->big_cqe[0], cqe->big_cqe[1]);
 114                 }
 115         }
 116
 117         /*
 118          * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
 119          * since fdinfo case grabs it in the opposite direction of normal use
 120          * cases. If we fail to get the lock, we just don't iterate any
 121          * structures that could be going away outside the io_uring mutex.
 122          */
 123         has_lock = mutex_trylock(&ctx->uring_lock);
 124
 125         if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
 126                 sq = ctx->sq_data;
 127                 if (!sq->thread)
 128                         sq = NULL;
 129         }
 130
 131         seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
 132         seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
 133         seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
 134         for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
 135                 struct file *f = io_file_from_index(&ctx->file_table, i);
 136
 137                 if (f)
 138                         seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
 139                 else
 140                         seq_printf(m, "%5u: <none>\n", i);
 141         }
 142         seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
 143         for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
 144                 struct io_mapped_ubuf *buf = ctx->user_bufs[i];
 145                 unsigned int len = buf->ubuf_end - buf->ubuf;
 146
 147                 seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, len);
 148         }
 149         if (has_lock && !xa_empty(&ctx->personalities)) {
 150                 unsigned long index;
 151                 const struct cred *cred;
 152
 153                 seq_printf(m, "Personalities:\n");
 154                 xa_for_each(&ctx->personalities, index, cred)
 155                         io_uring_show_cred(m, index, cred);
 156         }
 157         if (has_lock)
 158                 mutex_unlock(&ctx->uring_lock);
 159
 160         seq_puts(m, "PollList:\n");
 161         for (i = 0; i < (1U << ctx->cancel_table.hash_bits); i++) {
 162                 struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
 163                 struct io_kiocb *req;
 164
 165                 spin_lock(&hb->lock);
 166                 hlist_for_each_entry(req, &hb->list, hash_node)
 167                         seq_printf(m, "  op=%d, task_works=%d\n", req->opcode,
 168                                         task_work_pending(req->task));
 169                 spin_unlock(&hb->lock);
 170         }
 171
 172         seq_puts(m, "CqOverflowList:\n");
 173         spin_lock(&ctx->completion_lock);
 174         list_for_each_entry(ocqe, &ctx->cq_overflow_list, list) {
 175                 struct io_uring_cqe *cqe = &ocqe->cqe;
 176
 177                 seq_printf(m, "  user_data=%llu, res=%d, flags=%x\n",
 178                            cqe->user_data, cqe->res, cqe->flags);
 179
 180         }
 181
 182         spin_unlock(&ctx->completion_lock);
 183 }
 184
 185 __cold void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
 186 {
 187         struct io_ring_ctx *ctx = f->private_data;
 188
 189         if (percpu_ref_tryget(&ctx->refs)) {
 190                 __io_uring_show_fdinfo(ctx, m);
 191                 percpu_ref_put(&ctx->refs);
 192         }
 193 }
 194 #endif