io_uring/fdinfo.c - linux/kernel/git/paulmck/linux-rcu - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/file.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/io_uring.h>

 #include <uapi/linux/io_uring.h>

 #include "io_uring.h"
 #include "sqpoll.h"
 #include "fdinfo.h"
 #include "cancel.h"
 #include "rsrc.h"

 #ifdef CONFIG_PROC_FS
 static __cold int io_uring_show_cred(struct seq_file *m, unsigned int id,
 		const struct cred *cred)
 {
 	struct user_namespace *uns = seq_user_ns(m);
 	struct group_info *gi;
 	kernel_cap_t cap;
 	unsigned __capi;
 	int g;

 	seq_printf(m, "%5d\n", id);
 	seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
 	seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
 	seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
 	seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
 	seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
 	seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
 	seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
 	seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
 	seq_puts(m, "\n\tGroups:\t");
 	gi = cred->group_info;
 	for (g = 0; g < gi->ngroups; g++) {
 		seq_put_decimal_ull(m, g ? " " : "",
 					from_kgid_munged(uns, gi->gid[g]));
 	}
 	seq_puts(m, "\n\tCapEff:\t");
 	cap = cred->cap_effective;
 	CAP_FOR_EACH_U32(__capi)
 		seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
 	seq_putc(m, '\n');
 	return 0;
 }

 static __cold void __io_uring_show_fdinfo(struct io_ring_ctx *ctx,
 					  struct seq_file *m)
 {
 	struct io_sq_data *sq = NULL;
 	struct io_overflow_cqe *ocqe;
 	struct io_rings *r = ctx->rings;
 	unsigned int sq_mask = ctx->sq_entries - 1, cq_mask = ctx->cq_entries - 1;
 	unsigned int sq_head = READ_ONCE(r->sq.head);
 	unsigned int sq_tail = READ_ONCE(r->sq.tail);
 	unsigned int cq_head = READ_ONCE(r->cq.head);
 	unsigned int cq_tail = READ_ONCE(r->cq.tail);
 	unsigned int cq_shift = 0;
 	unsigned int sq_shift = 0;
 	unsigned int sq_entries, cq_entries;
 	bool has_lock;
 	unsigned int i;

 	if (ctx->flags & IORING_SETUP_CQE32)
 		cq_shift = 1;
 	if (ctx->flags & IORING_SETUP_SQE128)
 		sq_shift = 1;

 	/*
 	 * we may get imprecise sqe and cqe info if uring is actively running
 	 * since we get cached_sq_head and cached_cq_tail without uring_lock
 	 * and sq_tail and cq_head are changed by userspace. But it's ok since
 	 * we usually use these info when it is stuck.
 	 */
 	seq_printf(m, "SqMask:\t0x%x\n", sq_mask);
 	seq_printf(m, "SqHead:\t%u\n", sq_head);
 	seq_printf(m, "SqTail:\t%u\n", sq_tail);
 	seq_printf(m, "CachedSqHead:\t%u\n", ctx->cached_sq_head);
 	seq_printf(m, "CqMask:\t0x%x\n", cq_mask);
 	seq_printf(m, "CqHead:\t%u\n", cq_head);
 	seq_printf(m, "CqTail:\t%u\n", cq_tail);
 	seq_printf(m, "CachedCqTail:\t%u\n", ctx->cached_cq_tail);
 	seq_printf(m, "SQEs:\t%u\n", sq_tail - sq_head);
 	sq_entries = min(sq_tail - sq_head, ctx->sq_entries);
 	for (i = 0; i < sq_entries; i++) {
 		unsigned int entry = i + sq_head;
 		struct io_uring_sqe *sqe;
 		unsigned int sq_idx;

 		sq_idx = READ_ONCE(ctx->sq_array[entry & sq_mask]);
 		if (sq_idx > sq_mask)
 			continue;
 		sqe = &ctx->sq_sqes[sq_idx << sq_shift];
 		seq_printf(m, "%5u: opcode:%s, fd:%d, flags:%x, off:%llu, "
 			      "addr:0x%llx, rw_flags:0x%x, buf_index:%d "
 			      "user_data:%llu",
 			   sq_idx, io_uring_get_opcode(sqe->opcode), sqe->fd,
 			   sqe->flags, (unsigned long long) sqe->off,
 			   (unsigned long long) sqe->addr, sqe->rw_flags,
 			   sqe->buf_index, sqe->user_data);
 		if (sq_shift) {
 			u64 *sqeb = (void *) (sqe + 1);
 			int size = sizeof(struct io_uring_sqe) / sizeof(u64);
 			int j;

 			for (j = 0; j < size; j++) {
 				seq_printf(m, ", e%d:0x%llx", j,
 						(unsigned long long) *sqeb);
 				sqeb++;
 			}
 		}
 		seq_printf(m, "\n");
 	}
 	seq_printf(m, "CQEs:\t%u\n", cq_tail - cq_head);
 	cq_entries = min(cq_tail - cq_head, ctx->cq_entries);
 	for (i = 0; i < cq_entries; i++) {
 		unsigned int entry = i + cq_head;
 		struct io_uring_cqe *cqe = &r->cqes[(entry & cq_mask) << cq_shift];

 		seq_printf(m, "%5u: user_data:%llu, res:%d, flag:%x",
 			   entry & cq_mask, cqe->user_data, cqe->res,
 			   cqe->flags);
 		if (cq_shift)
 			seq_printf(m, ", extra1:%llu, extra2:%llu\n",
 					cqe->big_cqe[0], cqe->big_cqe[1]);
 		seq_printf(m, "\n");
 	}

 	/*
 	 * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
 	 * since fdinfo case grabs it in the opposite direction of normal use
 	 * cases. If we fail to get the lock, we just don't iterate any
 	 * structures that could be going away outside the io_uring mutex.
 	 */
 	has_lock = mutex_trylock(&ctx->uring_lock);

 	if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
 		sq = ctx->sq_data;
 		if (!sq->thread)
 			sq = NULL;
 	}

 	seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
 	seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
 	seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
 	for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
 		struct file *f = io_file_from_index(&ctx->file_table, i);

 		if (f)
 			seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
 		else
 			seq_printf(m, "%5u: <none>\n", i);
 	}
 	seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
 	for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
 		struct io_mapped_ubuf *buf = ctx->user_bufs[i];
 		unsigned int len = buf->ubuf_end - buf->ubuf;

 		seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, len);
 	}
 	if (has_lock && !xa_empty(&ctx->personalities)) {
 		unsigned long index;
 		const struct cred *cred;

 		seq_printf(m, "Personalities:\n");
 		xa_for_each(&ctx->personalities, index, cred)
 			io_uring_show_cred(m, index, cred);
 	}
 	if (has_lock)
 		mutex_unlock(&ctx->uring_lock);

 	seq_puts(m, "PollList:\n");
 	for (i = 0; i < (1U << ctx->cancel_table.hash_bits); i++) {
 		struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
 		struct io_kiocb *req;

 		spin_lock(&hb->lock);
 		hlist_for_each_entry(req, &hb->list, hash_node)
 			seq_printf(m, "  op=%d, task_works=%d\n", req->opcode,
 					task_work_pending(req->task));
 		spin_unlock(&hb->lock);
 	}

 	seq_puts(m, "CqOverflowList:\n");
 	spin_lock(&ctx->completion_lock);
 	list_for_each_entry(ocqe, &ctx->cq_overflow_list, list) {
 		struct io_uring_cqe *cqe = &ocqe->cqe;

 		seq_printf(m, "  user_data=%llu, res=%d, flags=%x\n",
 			   cqe->user_data, cqe->res, cqe->flags);

 	}

 	spin_unlock(&ctx->completion_lock);
 }

 __cold void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
 {
 	struct io_ring_ctx *ctx = f->private_data;

 	if (percpu_ref_tryget(&ctx->refs)) {
 		__io_uring_show_fdinfo(ctx, m);
 		percpu_ref_put(&ctx->refs);
 	}
 }
 #endif
	// SPDX-License-Identifier: GPL-2.0
	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/fs.h>
	#include <linux/file.h>
	#include <linux/proc_fs.h>
	#include <linux/seq_file.h>
	#include <linux/io_uring.h>

	#include <uapi/linux/io_uring.h>

	#include "io_uring.h"
	#include "sqpoll.h"
	#include "fdinfo.h"
	#include "cancel.h"
	#include "rsrc.h"

	#ifdef CONFIG_PROC_FS
	static __cold int io_uring_show_cred(struct seq_file *m, unsigned int id,
	const struct cred *cred)
	{
	struct user_namespace *uns = seq_user_ns(m);
	struct group_info *gi;
	kernel_cap_t cap;
	unsigned __capi;
	int g;

	seq_printf(m, "%5d\n", id);
	seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
	seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
	seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
	seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
	seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
	seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
	seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
	seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
	seq_puts(m, "\n\tGroups:\t");
	gi = cred->group_info;
	for (g = 0; g < gi->ngroups; g++) {
	seq_put_decimal_ull(m, g ? " " : "",
	from_kgid_munged(uns, gi->gid[g]));
	}
	seq_puts(m, "\n\tCapEff:\t");
	cap = cred->cap_effective;
	CAP_FOR_EACH_U32(__capi)
	seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
	seq_putc(m, '\n');
	return 0;
	}

	static __cold void __io_uring_show_fdinfo(struct io_ring_ctx *ctx,
	struct seq_file *m)
	{
	struct io_sq_data *sq = NULL;
	struct io_overflow_cqe *ocqe;
	struct io_rings *r = ctx->rings;
	unsigned int sq_mask = ctx->sq_entries - 1, cq_mask = ctx->cq_entries - 1;
	unsigned int sq_head = READ_ONCE(r->sq.head);
	unsigned int sq_tail = READ_ONCE(r->sq.tail);
	unsigned int cq_head = READ_ONCE(r->cq.head);
	unsigned int cq_tail = READ_ONCE(r->cq.tail);
	unsigned int cq_shift = 0;
	unsigned int sq_shift = 0;
	unsigned int sq_entries, cq_entries;
	bool has_lock;
	unsigned int i;

	if (ctx->flags & IORING_SETUP_CQE32)
	cq_shift = 1;
	if (ctx->flags & IORING_SETUP_SQE128)
	sq_shift = 1;

	/*
	* we may get imprecise sqe and cqe info if uring is actively running
	* since we get cached_sq_head and cached_cq_tail without uring_lock
	* and sq_tail and cq_head are changed by userspace. But it's ok since
	* we usually use these info when it is stuck.
	*/
	seq_printf(m, "SqMask:\t0x%x\n", sq_mask);
	seq_printf(m, "SqHead:\t%u\n", sq_head);
	seq_printf(m, "SqTail:\t%u\n", sq_tail);
	seq_printf(m, "CachedSqHead:\t%u\n", ctx->cached_sq_head);
	seq_printf(m, "CqMask:\t0x%x\n", cq_mask);
	seq_printf(m, "CqHead:\t%u\n", cq_head);
	seq_printf(m, "CqTail:\t%u\n", cq_tail);
	seq_printf(m, "CachedCqTail:\t%u\n", ctx->cached_cq_tail);
	seq_printf(m, "SQEs:\t%u\n", sq_tail - sq_head);
	sq_entries = min(sq_tail - sq_head, ctx->sq_entries);
	for (i = 0; i < sq_entries; i++) {
	unsigned int entry = i + sq_head;
	struct io_uring_sqe *sqe;
	unsigned int sq_idx;

	sq_idx = READ_ONCE(ctx->sq_array[entry & sq_mask]);
	if (sq_idx > sq_mask)
	continue;
	sqe = &ctx->sq_sqes[sq_idx << sq_shift];
	seq_printf(m, "%5u: opcode:%s, fd:%d, flags:%x, off:%llu, "
	"addr:0x%llx, rw_flags:0x%x, buf_index:%d "
	"user_data:%llu",
	sq_idx, io_uring_get_opcode(sqe->opcode), sqe->fd,
	sqe->flags, (unsigned long long) sqe->off,
	(unsigned long long) sqe->addr, sqe->rw_flags,
	sqe->buf_index, sqe->user_data);
	if (sq_shift) {
	u64 sqeb = (void ) (sqe + 1);
	int size = sizeof(struct io_uring_sqe) / sizeof(u64);
	int j;

	for (j = 0; j < size; j++) {
	seq_printf(m, ", e%d:0x%llx", j,
	(unsigned long long) *sqeb);
	sqeb++;
	}
	}
	seq_printf(m, "\n");
	}
	seq_printf(m, "CQEs:\t%u\n", cq_tail - cq_head);
	cq_entries = min(cq_tail - cq_head, ctx->cq_entries);
	for (i = 0; i < cq_entries; i++) {
	unsigned int entry = i + cq_head;
	struct io_uring_cqe *cqe = &r->cqes[(entry & cq_mask) << cq_shift];

	seq_printf(m, "%5u: user_data:%llu, res:%d, flag:%x",
	entry & cq_mask, cqe->user_data, cqe->res,
	cqe->flags);
	if (cq_shift)
	seq_printf(m, ", extra1:%llu, extra2:%llu\n",
	cqe->big_cqe[0], cqe->big_cqe[1]);
	seq_printf(m, "\n");
	}

	/*
	* Avoid ABBA deadlock between the seq lock and the io_uring mutex,
	* since fdinfo case grabs it in the opposite direction of normal use
	* cases. If we fail to get the lock, we just don't iterate any
	* structures that could be going away outside the io_uring mutex.
	*/
	has_lock = mutex_trylock(&ctx->uring_lock);

	if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
	sq = ctx->sq_data;
	if (!sq->thread)
	sq = NULL;
	}

	seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
	seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
	seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
	for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
	struct file *f = io_file_from_index(&ctx->file_table, i);

	if (f)
	seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
	else
	seq_printf(m, "%5u: <none>\n", i);
	}
	seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
	for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
	struct io_mapped_ubuf *buf = ctx->user_bufs[i];
	unsigned int len = buf->ubuf_end - buf->ubuf;

	seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, len);
	}
	if (has_lock && !xa_empty(&ctx->personalities)) {
	unsigned long index;
	const struct cred *cred;

	seq_printf(m, "Personalities:\n");
	xa_for_each(&ctx->personalities, index, cred)
	io_uring_show_cred(m, index, cred);
	}
	if (has_lock)
	mutex_unlock(&ctx->uring_lock);

	seq_puts(m, "PollList:\n");
	for (i = 0; i < (1U << ctx->cancel_table.hash_bits); i++) {
	struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
	struct io_kiocb *req;

	spin_lock(&hb->lock);
	hlist_for_each_entry(req, &hb->list, hash_node)
	seq_printf(m, " op=%d, task_works=%d\n", req->opcode,
	task_work_pending(req->task));
	spin_unlock(&hb->lock);
	}

	seq_puts(m, "CqOverflowList:\n");
	spin_lock(&ctx->completion_lock);
	list_for_each_entry(ocqe, &ctx->cq_overflow_list, list) {
	struct io_uring_cqe *cqe = &ocqe->cqe;

	seq_printf(m, " user_data=%llu, res=%d, flags=%x\n",
	cqe->user_data, cqe->res, cqe->flags);

	}

	spin_unlock(&ctx->completion_lock);
	}

	__cold void io_uring_show_fdinfo(struct seq_file m, struct file f)
	{
	struct io_ring_ctx *ctx = f->private_data;

	if (percpu_ref_tryget(&ctx->refs)) {
	__io_uring_show_fdinfo(ctx, m);
	percpu_ref_put(&ctx->refs);
	}
	}
	#endif