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