From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- io_uring/register.c | 1049 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1049 insertions(+) create mode 100644 io_uring/register.c (limited to 'io_uring/register.c') diff --git a/io_uring/register.c b/io_uring/register.c new file mode 100644 index 000000000..02bc103bc --- /dev/null +++ b/io_uring/register.c @@ -0,0 +1,1049 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Code related to the io_uring_register() syscall + * + * Copyright (C) 2023 Jens Axboe + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "filetable.h" +#include "io_uring.h" +#include "opdef.h" +#include "tctx.h" +#include "rsrc.h" +#include "sqpoll.h" +#include "register.h" +#include "cancel.h" +#include "kbuf.h" +#include "napi.h" +#include "eventfd.h" +#include "msg_ring.h" +#include "memmap.h" +#include "zcrx.h" +#include "query.h" +#include "bpf_filter.h" + +#define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \ + IORING_REGISTER_LAST + IORING_OP_LAST) + +static __cold int io_probe(struct io_ring_ctx *ctx, void __user *arg, + unsigned nr_args) +{ + struct io_uring_probe *p; + size_t size; + int i, ret; + + if (nr_args > IORING_OP_LAST) + nr_args = IORING_OP_LAST; + + size = struct_size(p, ops, nr_args); + p = memdup_user(arg, size); + if (IS_ERR(p)) + return PTR_ERR(p); + ret = -EINVAL; + if (memchr_inv(p, 0, size)) + goto out; + + p->last_op = IORING_OP_LAST - 1; + + for (i = 0; i < nr_args; i++) { + p->ops[i].op = i; + if (io_uring_op_supported(i)) + p->ops[i].flags = IO_URING_OP_SUPPORTED; + } + p->ops_len = i; + + ret = 0; + if (copy_to_user(arg, p, size)) + ret = -EFAULT; +out: + kfree(p); + return ret; +} + +int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id) +{ + const struct cred *creds; + + creds = xa_erase(&ctx->personalities, id); + if (creds) { + put_cred(creds); + return 0; + } + + return -EINVAL; +} + + +static int io_register_personality(struct io_ring_ctx *ctx) +{ + const struct cred *creds; + u32 id; + int ret; + + creds = get_current_cred(); + + ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)creds, + XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL); + if (ret < 0) { + put_cred(creds); + return ret; + } + return id; +} + +/* + * Returns number of restrictions parsed and added on success, or < 0 for + * an error. + */ +static __cold int io_parse_restrictions(void __user *arg, unsigned int nr_args, + struct io_restriction *restrictions) +{ + struct io_uring_restriction *res; + size_t size; + int i, ret; + + if (!arg || nr_args > IORING_MAX_RESTRICTIONS) + return -EINVAL; + + size = array_size(nr_args, sizeof(*res)); + if (size == SIZE_MAX) + return -EOVERFLOW; + + res = memdup_user(arg, size); + if (IS_ERR(res)) + return PTR_ERR(res); + + ret = -EINVAL; + + for (i = 0; i < nr_args; i++) { + switch (res[i].opcode) { + case IORING_RESTRICTION_REGISTER_OP: + if (res[i].register_op >= IORING_REGISTER_LAST) + goto err; + __set_bit(res[i].register_op, restrictions->register_op); + restrictions->reg_registered = true; + break; + case IORING_RESTRICTION_SQE_OP: + if (res[i].sqe_op >= IORING_OP_LAST) + goto err; + __set_bit(res[i].sqe_op, restrictions->sqe_op); + restrictions->op_registered = true; + break; + case IORING_RESTRICTION_SQE_FLAGS_ALLOWED: + restrictions->sqe_flags_allowed = res[i].sqe_flags; + restrictions->op_registered = true; + break; + case IORING_RESTRICTION_SQE_FLAGS_REQUIRED: + restrictions->sqe_flags_required = res[i].sqe_flags; + restrictions->op_registered = true; + break; + default: + goto err; + } + } + ret = nr_args; + if (!nr_args) { + restrictions->op_registered = true; + restrictions->reg_registered = true; + } +err: + kfree(res); + return ret; +} + +static __cold int io_register_restrictions(struct io_ring_ctx *ctx, + void __user *arg, unsigned int nr_args) +{ + int ret; + + /* Restrictions allowed only if rings started disabled */ + if (!(ctx->flags & IORING_SETUP_R_DISABLED)) + return -EBADFD; + + /* We allow only a single restrictions registration */ + if (ctx->restrictions.op_registered || ctx->restrictions.reg_registered) + return -EBUSY; + + ret = io_parse_restrictions(arg, nr_args, &ctx->restrictions); + /* + * Reset all restrictions if an error happened, but retain any COW'ed + * settings. + */ + if (ret < 0) { + struct io_bpf_filters *bpf = ctx->restrictions.bpf_filters; + bool cowed = ctx->restrictions.bpf_filters_cow; + + memset(&ctx->restrictions, 0, sizeof(ctx->restrictions)); + ctx->restrictions.bpf_filters = bpf; + ctx->restrictions.bpf_filters_cow = cowed; + return ret; + } + if (ctx->restrictions.op_registered) + ctx->int_flags |= IO_RING_F_OP_RESTRICTED; + if (ctx->restrictions.reg_registered) + ctx->int_flags |= IO_RING_F_REG_RESTRICTED; + return 0; +} + +static int io_register_restrictions_task(void __user *arg, unsigned int nr_args) +{ + struct io_uring_task_restriction __user *ures = arg; + struct io_uring_task_restriction tres; + struct io_restriction *res; + int ret; + + /* Disallow if task already has registered restrictions */ + if (current->io_uring_restrict) + return -EPERM; + /* + * Similar to seccomp, disallow setting a filter if task_no_new_privs + * is false and we're not CAP_SYS_ADMIN. + */ + if (!task_no_new_privs(current) && + !ns_capable_noaudit(current_user_ns(), CAP_SYS_ADMIN)) + return -EACCES; + if (nr_args != 1) + return -EINVAL; + + if (copy_from_user(&tres, arg, sizeof(tres))) + return -EFAULT; + + if (tres.flags) + return -EINVAL; + if (!mem_is_zero(tres.resv, sizeof(tres.resv))) + return -EINVAL; + + res = kzalloc_obj(*res, GFP_KERNEL_ACCOUNT); + if (!res) + return -ENOMEM; + + ret = io_parse_restrictions(ures->restrictions, tres.nr_res, res); + if (ret < 0) { + kfree(res); + return ret; + } + current->io_uring_restrict = res; + return 0; +} + +static int io_register_bpf_filter_task(void __user *arg, unsigned int nr_args) +{ + struct io_restriction *res; + int ret; + + /* + * Similar to seccomp, disallow setting a filter if task_no_new_privs + * is false and we're not CAP_SYS_ADMIN. + */ + if (!task_no_new_privs(current) && + !ns_capable_noaudit(current_user_ns(), CAP_SYS_ADMIN)) + return -EACCES; + + if (nr_args != 1) + return -EINVAL; + + /* If no task restrictions exist, setup a new set */ + res = current->io_uring_restrict; + if (!res) { + res = kzalloc_obj(*res, GFP_KERNEL_ACCOUNT); + if (!res) + return -ENOMEM; + } + + ret = io_register_bpf_filter(res, arg); + if (ret) { + if (res != current->io_uring_restrict) + kfree(res); + return ret; + } + if (!current->io_uring_restrict) + current->io_uring_restrict = res; + return 0; +} + +static int io_register_enable_rings(struct io_ring_ctx *ctx) +{ + if (!(ctx->flags & IORING_SETUP_R_DISABLED)) + return -EBADFD; + + if (ctx->flags & IORING_SETUP_SINGLE_ISSUER) { + ctx->submitter_task = get_task_struct(current); + /* + * Lazy activation attempts would fail if it was polled before + * submitter_task is set. + */ + if (wq_has_sleeper(&ctx->poll_wq)) + io_activate_pollwq(ctx); + } + + /* Keep submitter_task store before clearing IORING_SETUP_R_DISABLED */ + smp_store_release(&ctx->flags, ctx->flags & ~IORING_SETUP_R_DISABLED); + if (ctx->sq_data && wq_has_sleeper(&ctx->sq_data->wait)) + wake_up(&ctx->sq_data->wait); + return 0; +} + +static __cold int __io_register_iowq_aff(struct io_ring_ctx *ctx, + cpumask_var_t new_mask) +{ + int ret; + + if (!(ctx->flags & IORING_SETUP_SQPOLL)) { + ret = io_wq_cpu_affinity(current->io_uring, new_mask); + } else { + mutex_unlock(&ctx->uring_lock); + ret = io_sqpoll_wq_cpu_affinity(ctx, new_mask); + mutex_lock(&ctx->uring_lock); + } + + return ret; +} + +static __cold int io_register_iowq_aff(struct io_ring_ctx *ctx, + void __user *arg, unsigned len) +{ + cpumask_var_t new_mask; + int ret; + + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) + return -ENOMEM; + + cpumask_clear(new_mask); + if (len > cpumask_size()) + len = cpumask_size(); + +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + ret = compat_get_bitmap(cpumask_bits(new_mask), + (const compat_ulong_t __user *)arg, + len * 8 /* CHAR_BIT */); + else +#endif + ret = copy_from_user(new_mask, arg, len); + + if (ret) { + free_cpumask_var(new_mask); + return -EFAULT; + } + + ret = __io_register_iowq_aff(ctx, new_mask); + free_cpumask_var(new_mask); + return ret; +} + +static __cold int io_unregister_iowq_aff(struct io_ring_ctx *ctx) +{ + return __io_register_iowq_aff(ctx, NULL); +} + +static __cold int io_register_iowq_max_workers(struct io_ring_ctx *ctx, + void __user *arg) + __must_hold(&ctx->uring_lock) +{ + struct io_tctx_node *node; + struct io_uring_task *tctx = NULL; + struct io_sq_data *sqd = NULL; + __u32 new_count[2]; + int i, ret; + + if (copy_from_user(new_count, arg, sizeof(new_count))) + return -EFAULT; + for (i = 0; i < ARRAY_SIZE(new_count); i++) + if (new_count[i] > INT_MAX) + return -EINVAL; + + if (ctx->flags & IORING_SETUP_SQPOLL) { + sqd = ctx->sq_data; + if (sqd) { + struct task_struct *tsk; + + /* + * Observe the correct sqd->lock -> ctx->uring_lock + * ordering. Fine to drop uring_lock here, we hold + * a ref to the ctx. + */ + refcount_inc(&sqd->refs); + mutex_unlock(&ctx->uring_lock); + mutex_lock(&sqd->lock); + mutex_lock(&ctx->uring_lock); + tsk = sqpoll_task_locked(sqd); + if (tsk) + tctx = tsk->io_uring; + } + } else { + tctx = current->io_uring; + } + + BUILD_BUG_ON(sizeof(new_count) != sizeof(ctx->iowq_limits)); + + for (i = 0; i < ARRAY_SIZE(new_count); i++) + if (new_count[i]) + ctx->iowq_limits[i] = new_count[i]; + ctx->int_flags |= IO_RING_F_IOWQ_LIMITS_SET; + + if (tctx && tctx->io_wq) { + ret = io_wq_max_workers(tctx->io_wq, new_count); + if (ret) + goto err; + } else { + memset(new_count, 0, sizeof(new_count)); + } + + if (sqd) { + mutex_unlock(&ctx->uring_lock); + mutex_unlock(&sqd->lock); + io_put_sq_data(sqd); + mutex_lock(&ctx->uring_lock); + } + + if (copy_to_user(arg, new_count, sizeof(new_count))) + return -EFAULT; + + /* that's it for SQPOLL, only the SQPOLL task creates requests */ + if (sqd) + return 0; + + /* now propagate the restriction to all registered users */ + mutex_lock(&ctx->tctx_lock); + list_for_each_entry(node, &ctx->tctx_list, ctx_node) { + tctx = node->task->io_uring; + if (WARN_ON_ONCE(!tctx->io_wq)) + continue; + + for (i = 0; i < ARRAY_SIZE(new_count); i++) + new_count[i] = ctx->iowq_limits[i]; + /* ignore errors, it always returns zero anyway */ + (void)io_wq_max_workers(tctx->io_wq, new_count); + } + mutex_unlock(&ctx->tctx_lock); + return 0; +err: + if (sqd) { + mutex_unlock(&ctx->uring_lock); + mutex_unlock(&sqd->lock); + io_put_sq_data(sqd); + mutex_lock(&ctx->uring_lock); + } + return ret; +} + +static int io_register_clock(struct io_ring_ctx *ctx, + struct io_uring_clock_register __user *arg) +{ + struct io_uring_clock_register reg; + + if (copy_from_user(®, arg, sizeof(reg))) + return -EFAULT; + if (memchr_inv(®.__resv, 0, sizeof(reg.__resv))) + return -EINVAL; + + switch (reg.clockid) { + case CLOCK_MONOTONIC: + ctx->clock_offset = 0; + break; + case CLOCK_BOOTTIME: + ctx->clock_offset = TK_OFFS_BOOT; + break; + default: + return -EINVAL; + } + + ctx->clockid = reg.clockid; + return 0; +} + +/* + * State to maintain until we can swap. Both new and old state, used for + * either mapping or freeing. + */ +struct io_ring_ctx_rings { + struct io_rings *rings; + struct io_uring_sqe *sq_sqes; + + struct io_mapped_region sq_region; + struct io_mapped_region ring_region; +}; + +static void io_register_free_rings(struct io_ring_ctx *ctx, + struct io_ring_ctx_rings *r) +{ + io_free_region(ctx->user, &r->sq_region); + io_free_region(ctx->user, &r->ring_region); +} + +#define swap_old(ctx, o, n, field) \ + do { \ + (o).field = (ctx)->field; \ + (ctx)->field = (n).field; \ + } while (0) + +#define RESIZE_FLAGS (IORING_SETUP_CQSIZE | IORING_SETUP_CLAMP) +#define COPY_FLAGS (IORING_SETUP_NO_SQARRAY | IORING_SETUP_SQE128 | \ + IORING_SETUP_CQE32 | IORING_SETUP_NO_MMAP | \ + IORING_SETUP_CQE_MIXED | IORING_SETUP_SQE_MIXED) + +static int io_register_resize_rings(struct io_ring_ctx *ctx, void __user *arg) +{ + struct io_ctx_config config; + struct io_uring_region_desc rd; + struct io_ring_ctx_rings o = { }, n = { }, *to_free = NULL; + unsigned i, tail, old_head; + struct io_uring_params *p = &config.p; + struct io_rings_layout *rl = &config.layout; + u32 *o_sq_array, *n_sq_array = NULL; + int ret; + + memset(&config, 0, sizeof(config)); + + /* limited to DEFER_TASKRUN for now */ + if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) + return -EINVAL; + if (copy_from_user(p, arg, sizeof(*p))) + return -EFAULT; + if (p->flags & ~RESIZE_FLAGS) + return -EINVAL; + + /* properties that are always inherited */ + p->flags |= (ctx->flags & COPY_FLAGS); + + ret = io_prepare_config(&config); + if (unlikely(ret)) + return ret; + + memset(&rd, 0, sizeof(rd)); + rd.size = PAGE_ALIGN(rl->rings_size); + if (p->flags & IORING_SETUP_NO_MMAP) { + rd.user_addr = p->cq_off.user_addr; + rd.flags |= IORING_MEM_REGION_TYPE_USER; + } + ret = io_create_region(ctx, &n.ring_region, &rd, IORING_OFF_CQ_RING); + if (ret) + return ret; + + n.rings = io_region_get_ptr(&n.ring_region); + + /* + * At this point n.rings is shared with userspace, just like o.rings + * is as well. While we don't expect userspace to modify it while + * a resize is in progress, and it's most likely that userspace will + * shoot itself in the foot if it does, we can't always assume good + * intent... Use read/write once helpers from here on to indicate the + * shared nature of it. + */ + WRITE_ONCE(n.rings->sq_ring_mask, p->sq_entries - 1); + WRITE_ONCE(n.rings->cq_ring_mask, p->cq_entries - 1); + WRITE_ONCE(n.rings->sq_ring_entries, p->sq_entries); + WRITE_ONCE(n.rings->cq_ring_entries, p->cq_entries); + + if (copy_to_user(arg, p, sizeof(*p))) { + io_register_free_rings(ctx, &n); + return -EFAULT; + } + + memset(&rd, 0, sizeof(rd)); + rd.size = PAGE_ALIGN(rl->sq_size); + if (p->flags & IORING_SETUP_NO_MMAP) { + rd.user_addr = p->sq_off.user_addr; + rd.flags |= IORING_MEM_REGION_TYPE_USER; + } + ret = io_create_region(ctx, &n.sq_region, &rd, IORING_OFF_SQES); + if (ret) { + io_register_free_rings(ctx, &n); + return ret; + } + n.sq_sqes = io_region_get_ptr(&n.sq_region); + + /* + * If using SQPOLL, park the thread + */ + if (ctx->sq_data) { + mutex_unlock(&ctx->uring_lock); + io_sq_thread_park(ctx->sq_data); + mutex_lock(&ctx->uring_lock); + } + + /* + * We'll do the swap. Grab the ctx->mmap_lock, which will exclude + * any new mmap's on the ring fd. Clear out existing mappings to prevent + * mmap from seeing them, as we'll unmap them. Any attempt to mmap + * existing rings beyond this point will fail. Not that it could proceed + * at this point anyway, as the io_uring mmap side needs go grab the + * ctx->mmap_lock as well. Likewise, hold the completion lock over the + * duration of the actual swap. + */ + mutex_lock(&ctx->mmap_lock); + spin_lock(&ctx->completion_lock); + o.rings = ctx->rings; + ctx->rings = NULL; + o.sq_sqes = ctx->sq_sqes; + ctx->sq_sqes = NULL; + o_sq_array = ctx->sq_array; + if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) + n_sq_array = (u32 *)((char *)n.rings + rl->sq_array_offset); + + /* + * Now copy SQ and CQ entries, if any. If either of the destination + * rings can't hold what is already there, then fail the operation. + */ + tail = READ_ONCE(o.rings->sq.tail); + old_head = READ_ONCE(o.rings->sq.head); + if (tail - old_head > p->sq_entries) + goto overflow; + for (i = old_head; i < tail; i++) { + unsigned int dst, src; + size_t sq_size; + + dst = i & (p->sq_entries - 1); + src = i & (ctx->sq_entries - 1); + if (n_sq_array) { + src = READ_ONCE(o_sq_array[src]); + if (unlikely(src >= ctx->sq_entries)) { + WRITE_ONCE(n_sq_array[dst], UINT_MAX); + continue; + } + WRITE_ONCE(n_sq_array[dst], dst); + } + + sq_size = sizeof(struct io_uring_sqe); + if (ctx->flags & IORING_SETUP_SQE128) { + dst <<= 1; + src <<= 1; + sq_size <<= 1; + } + memcpy(&n.sq_sqes[dst], &o.sq_sqes[src], sq_size); + } + WRITE_ONCE(n.rings->sq.head, old_head); + WRITE_ONCE(n.rings->sq.tail, tail); + + tail = READ_ONCE(o.rings->cq.tail); + old_head = READ_ONCE(o.rings->cq.head); + if (tail - old_head > p->cq_entries) { +overflow: + /* restore old rings, and return -EOVERFLOW via cleanup path */ + ctx->rings = o.rings; + ctx->sq_sqes = o.sq_sqes; + to_free = &n; + ret = -EOVERFLOW; + goto out; + } + for (i = old_head; i < tail; i++) { + unsigned index, dst_mask, src_mask; + size_t cq_size; + + index = i; + cq_size = sizeof(struct io_uring_cqe); + src_mask = ctx->cq_entries - 1; + dst_mask = p->cq_entries - 1; + if (ctx->flags & IORING_SETUP_CQE32) { + index <<= 1; + cq_size <<= 1; + src_mask = (ctx->cq_entries << 1) - 1; + dst_mask = (p->cq_entries << 1) - 1; + } + memcpy(&n.rings->cqes[index & dst_mask], &o.rings->cqes[index & src_mask], cq_size); + } + WRITE_ONCE(n.rings->cq.head, old_head); + WRITE_ONCE(n.rings->cq.tail, tail); + /* invalidate cached cqe refill */ + ctx->cqe_cached = ctx->cqe_sentinel = NULL; + + WRITE_ONCE(n.rings->sq_dropped, READ_ONCE(o.rings->sq_dropped)); + atomic_set(&n.rings->sq_flags, atomic_read(&o.rings->sq_flags)); + WRITE_ONCE(n.rings->cq_flags, READ_ONCE(o.rings->cq_flags)); + WRITE_ONCE(n.rings->cq_overflow, READ_ONCE(o.rings->cq_overflow)); + + /* all done, store old pointers and assign new ones */ + if (n_sq_array) + ctx->sq_array = n_sq_array; + + ctx->sq_entries = p->sq_entries; + ctx->cq_entries = p->cq_entries; + + /* + * Just mark any flag we may have missed and that the application + * should act on unconditionally. Worst case it'll be an extra + * syscall. + */ + atomic_or(IORING_SQ_TASKRUN | IORING_SQ_NEED_WAKEUP, &n.rings->sq_flags); + ctx->rings = n.rings; + rcu_assign_pointer(ctx->rings_rcu, n.rings); + + ctx->sq_sqes = n.sq_sqes; + swap_old(ctx, o, n, ring_region); + swap_old(ctx, o, n, sq_region); + to_free = &o; + ret = 0; +out: + spin_unlock(&ctx->completion_lock); + mutex_unlock(&ctx->mmap_lock); + /* Wait for concurrent io_ctx_mark_taskrun() */ + if (to_free == &o) + synchronize_rcu_expedited(); + io_register_free_rings(ctx, to_free); + + if (ctx->sq_data) + io_sq_thread_unpark(ctx->sq_data); + + return ret; +} + +static int io_register_mem_region(struct io_ring_ctx *ctx, void __user *uarg) +{ + struct io_uring_mem_region_reg __user *reg_uptr = uarg; + struct io_uring_mem_region_reg reg; + struct io_uring_region_desc __user *rd_uptr; + struct io_uring_region_desc rd; + struct io_mapped_region region = {}; + int ret; + + if (io_region_is_set(&ctx->param_region)) + return -EBUSY; + if (copy_from_user(®, reg_uptr, sizeof(reg))) + return -EFAULT; + rd_uptr = u64_to_user_ptr(reg.region_uptr); + if (copy_from_user(&rd, rd_uptr, sizeof(rd))) + return -EFAULT; + if (memchr_inv(®.__resv, 0, sizeof(reg.__resv))) + return -EINVAL; + if (reg.flags & ~IORING_MEM_REGION_REG_WAIT_ARG) + return -EINVAL; + + /* + * This ensures there are no waiters. Waiters are unlocked and it's + * hard to synchronise with them, especially if we need to initialise + * the region. + */ + if ((reg.flags & IORING_MEM_REGION_REG_WAIT_ARG) && + !(ctx->flags & IORING_SETUP_R_DISABLED)) + return -EINVAL; + + ret = io_create_region(ctx, ®ion, &rd, IORING_MAP_OFF_PARAM_REGION); + if (ret) + return ret; + if (copy_to_user(rd_uptr, &rd, sizeof(rd))) { + io_free_region(ctx->user, ®ion); + return -EFAULT; + } + + if (reg.flags & IORING_MEM_REGION_REG_WAIT_ARG) { + ctx->cq_wait_arg = io_region_get_ptr(®ion); + ctx->cq_wait_size = rd.size; + } + + io_region_publish(ctx, ®ion, &ctx->param_region); + return 0; +} + +static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, + void __user *arg, unsigned nr_args) + __releases(ctx->uring_lock) + __acquires(ctx->uring_lock) +{ + int ret; + + /* + * We don't quiesce the refs for register anymore and so it can't be + * dying as we're holding a file ref here. + */ + if (WARN_ON_ONCE(percpu_ref_is_dying(&ctx->refs))) + return -ENXIO; + + if (ctx->submitter_task && ctx->submitter_task != current) + return -EEXIST; + + if ((ctx->int_flags & IO_RING_F_REG_RESTRICTED) && !(ctx->flags & IORING_SETUP_R_DISABLED)) { + opcode = array_index_nospec(opcode, IORING_REGISTER_LAST); + if (!test_bit(opcode, ctx->restrictions.register_op)) + return -EACCES; + } + + switch (opcode) { + case IORING_REGISTER_BUFFERS: + ret = -EFAULT; + if (!arg) + break; + ret = io_sqe_buffers_register(ctx, arg, nr_args, NULL); + break; + case IORING_UNREGISTER_BUFFERS: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_sqe_buffers_unregister(ctx); + break; + case IORING_REGISTER_FILES: + ret = -EFAULT; + if (!arg) + break; + ret = io_sqe_files_register(ctx, arg, nr_args, NULL); + break; + case IORING_UNREGISTER_FILES: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_sqe_files_unregister(ctx); + break; + case IORING_REGISTER_FILES_UPDATE: + ret = io_register_files_update(ctx, arg, nr_args); + break; + case IORING_REGISTER_EVENTFD: + ret = -EINVAL; + if (nr_args != 1) + break; + ret = io_eventfd_register(ctx, arg, 0); + break; + case IORING_REGISTER_EVENTFD_ASYNC: + ret = -EINVAL; + if (nr_args != 1) + break; + ret = io_eventfd_register(ctx, arg, 1); + break; + case IORING_UNREGISTER_EVENTFD: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_eventfd_unregister(ctx); + break; + case IORING_REGISTER_PROBE: + ret = -EINVAL; + if (!arg || nr_args > 256) + break; + ret = io_probe(ctx, arg, nr_args); + break; + case IORING_REGISTER_PERSONALITY: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_register_personality(ctx); + break; + case IORING_UNREGISTER_PERSONALITY: + ret = -EINVAL; + if (arg) + break; + ret = io_unregister_personality(ctx, nr_args); + break; + case IORING_REGISTER_ENABLE_RINGS: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_register_enable_rings(ctx); + break; + case IORING_REGISTER_RESTRICTIONS: + ret = io_register_restrictions(ctx, arg, nr_args); + break; + case IORING_REGISTER_FILES2: + ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_FILE); + break; + case IORING_REGISTER_FILES_UPDATE2: + ret = io_register_rsrc_update(ctx, arg, nr_args, + IORING_RSRC_FILE); + break; + case IORING_REGISTER_BUFFERS2: + ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_BUFFER); + break; + case IORING_REGISTER_BUFFERS_UPDATE: + ret = io_register_rsrc_update(ctx, arg, nr_args, + IORING_RSRC_BUFFER); + break; + case IORING_REGISTER_IOWQ_AFF: + ret = -EINVAL; + if (!arg || !nr_args) + break; + ret = io_register_iowq_aff(ctx, arg, nr_args); + break; + case IORING_UNREGISTER_IOWQ_AFF: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_unregister_iowq_aff(ctx); + break; + case IORING_REGISTER_IOWQ_MAX_WORKERS: + ret = -EINVAL; + if (!arg || nr_args != 2) + break; + ret = io_register_iowq_max_workers(ctx, arg); + break; + case IORING_REGISTER_RING_FDS: + ret = io_ringfd_register(ctx, arg, nr_args); + break; + case IORING_UNREGISTER_RING_FDS: + ret = io_ringfd_unregister(ctx, arg, nr_args); + break; + case IORING_REGISTER_PBUF_RING: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_pbuf_ring(ctx, arg); + break; + case IORING_UNREGISTER_PBUF_RING: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_unregister_pbuf_ring(ctx, arg); + break; + case IORING_REGISTER_SYNC_CANCEL: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_sync_cancel(ctx, arg); + break; + case IORING_REGISTER_FILE_ALLOC_RANGE: + ret = -EINVAL; + if (!arg || nr_args) + break; + ret = io_register_file_alloc_range(ctx, arg); + break; + case IORING_REGISTER_PBUF_STATUS: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_pbuf_status(ctx, arg); + break; + case IORING_REGISTER_NAPI: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_napi(ctx, arg); + break; + case IORING_UNREGISTER_NAPI: + ret = -EINVAL; + if (nr_args != 1) + break; + ret = io_unregister_napi(ctx, arg); + break; + case IORING_REGISTER_CLOCK: + ret = -EINVAL; + if (!arg || nr_args) + break; + ret = io_register_clock(ctx, arg); + break; + case IORING_REGISTER_CLONE_BUFFERS: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_clone_buffers(ctx, arg); + break; + case IORING_REGISTER_ZCRX_IFQ: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_zcrx(ctx, arg); + break; + case IORING_REGISTER_RESIZE_RINGS: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_resize_rings(ctx, arg); + break; + case IORING_REGISTER_MEM_REGION: + ret = -EINVAL; + if (!arg || nr_args != 1) + break; + ret = io_register_mem_region(ctx, arg); + break; + case IORING_REGISTER_QUERY: + ret = io_query(arg, nr_args); + break; + case IORING_REGISTER_ZCRX_CTRL: + ret = io_zcrx_ctrl(ctx, arg, nr_args); + break; + case IORING_REGISTER_BPF_FILTER: + ret = -EINVAL; + + if (nr_args != 1) + break; + ret = io_register_bpf_filter(&ctx->restrictions, arg); + if (!ret) + WRITE_ONCE(ctx->bpf_filters, + ctx->restrictions.bpf_filters->filters); + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +static int io_uring_register_send_msg_ring(void __user *arg, unsigned int nr_args) +{ + struct io_uring_sqe sqe; + + if (!arg || nr_args != 1) + return -EINVAL; + if (copy_from_user(&sqe, arg, sizeof(sqe))) + return -EFAULT; + /* no flags supported */ + if (sqe.flags) + return -EINVAL; + if (sqe.opcode != IORING_OP_MSG_RING) + return -EINVAL; + + return io_uring_sync_msg_ring(&sqe); +} + +/* + * "blind" registration opcodes are ones where there's no ring given, and + * hence the source fd must be -1. + */ +static int io_uring_register_blind(unsigned int opcode, void __user *arg, + unsigned int nr_args) +{ + switch (opcode) { + case IORING_REGISTER_SEND_MSG_RING: + return io_uring_register_send_msg_ring(arg, nr_args); + case IORING_REGISTER_QUERY: + return io_query(arg, nr_args); + case IORING_REGISTER_RESTRICTIONS: + return io_register_restrictions_task(arg, nr_args); + case IORING_REGISTER_BPF_FILTER: + return io_register_bpf_filter_task(arg, nr_args); + } + return -EINVAL; +} + +SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, + void __user *, arg, unsigned int, nr_args) +{ + struct io_ring_ctx *ctx; + long ret = -EBADF; + struct file *file; + bool use_registered_ring; + + use_registered_ring = !!(opcode & IORING_REGISTER_USE_REGISTERED_RING); + opcode &= ~IORING_REGISTER_USE_REGISTERED_RING; + + if (opcode >= IORING_REGISTER_LAST) + return -EINVAL; + + if (fd == -1) + return io_uring_register_blind(opcode, arg, nr_args); + + file = io_uring_ctx_get_file(fd, use_registered_ring); + if (IS_ERR(file)) + return PTR_ERR(file); + ctx = file->private_data; + + mutex_lock(&ctx->uring_lock); + ret = __io_uring_register(ctx, opcode, arg, nr_args); + + trace_io_uring_register(ctx, opcode, ctx->file_table.data.nr, + ctx->buf_table.nr, ret); + mutex_unlock(&ctx->uring_lock); + + if (!use_registered_ring) + fput(file); + return ret; +} -- cgit v1.3.1