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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /io_uring/tctx.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'io_uring/tctx.c')
-rw-r--r--io_uring/tctx.c424
1 files changed, 424 insertions, 0 deletions
diff --git a/io_uring/tctx.c b/io_uring/tctx.c
new file mode 100644
index 000000000..466b7300e
--- /dev/null
+++ b/io_uring/tctx.c
@@ -0,0 +1,424 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/file.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/nospec.h>
+#include <linux/io_uring.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "io_uring.h"
+#include "tctx.h"
+#include "bpf_filter.h"
+
+static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx,
+ struct task_struct *task)
+{
+ struct io_wq_hash *hash;
+ struct io_wq_data data;
+ unsigned int concurrency;
+
+ mutex_lock(&ctx->uring_lock);
+ hash = ctx->hash_map;
+ if (!hash) {
+ hash = kzalloc_obj(*hash);
+ if (!hash) {
+ mutex_unlock(&ctx->uring_lock);
+ return ERR_PTR(-ENOMEM);
+ }
+ refcount_set(&hash->refs, 1);
+ init_waitqueue_head(&hash->wait);
+ ctx->hash_map = hash;
+ }
+ mutex_unlock(&ctx->uring_lock);
+
+ data.hash = hash;
+ data.task = task;
+
+ /* Do QD, or 4 * CPUS, whatever is smallest */
+ concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
+
+ return io_wq_create(concurrency, &data);
+}
+
+void io_uring_free_tctx(struct task_struct *tsk)
+{
+ struct io_uring_task *tctx = tsk->io_uring;
+ struct io_tctx_node *node;
+ unsigned long index;
+
+ /*
+ * Fault injection forcing allocation errors in the xa_store() path
+ * can lead to xa_empty() returning false, even though no actual
+ * node is stored in the xarray. Until that gets sorted out, attempt
+ * an iteration here and warn if any entries are found.
+ */
+ if (tctx) {
+ xa_for_each(&tctx->xa, index, node) {
+ WARN_ON_ONCE(1);
+ break;
+ }
+ WARN_ON_ONCE(tctx->io_wq);
+ WARN_ON_ONCE(tctx->cached_refs);
+
+ percpu_counter_destroy(&tctx->inflight);
+ kfree(tctx);
+ tsk->io_uring = NULL;
+ }
+}
+
+void __io_uring_free(struct task_struct *tsk)
+{
+ io_uring_free_tctx(tsk);
+ if (tsk->io_uring_restrict) {
+ io_put_bpf_filters(tsk->io_uring_restrict);
+ kfree(tsk->io_uring_restrict);
+ tsk->io_uring_restrict = NULL;
+ }
+}
+
+__cold struct io_uring_task *io_uring_alloc_task_context(struct task_struct *task,
+ struct io_ring_ctx *ctx)
+{
+ struct io_uring_task *tctx;
+ int ret;
+
+ tctx = kzalloc_obj(*tctx);
+ if (unlikely(!tctx))
+ return ERR_PTR(-ENOMEM);
+
+ ret = percpu_counter_init(&tctx->inflight, 0, GFP_KERNEL);
+ if (unlikely(ret)) {
+ kfree(tctx);
+ return ERR_PTR(ret);
+ }
+
+ tctx->io_wq = io_init_wq_offload(ctx, task);
+ if (IS_ERR(tctx->io_wq)) {
+ ret = PTR_ERR(tctx->io_wq);
+ percpu_counter_destroy(&tctx->inflight);
+ kfree(tctx);
+ return ERR_PTR(ret);
+ }
+
+ tctx->task = task;
+ xa_init(&tctx->xa);
+ init_waitqueue_head(&tctx->wait);
+ atomic_set(&tctx->in_cancel, 0);
+ atomic_set(&tctx->inflight_tracked, 0);
+ mpscq_init(&tctx->task_list, &tctx->task_head);
+ INIT_WORK(&tctx->fallback_work, io_tctx_fallback_work);
+ init_task_work(&tctx->task_work, tctx_task_work);
+ return tctx;
+}
+
+static int io_tctx_install_node(struct io_ring_ctx *ctx,
+ struct io_uring_task *tctx)
+{
+ struct io_tctx_node *node;
+ int ret;
+
+ if (xa_load(&tctx->xa, (unsigned long)ctx))
+ return 0;
+
+ node = kmalloc_obj(*node);
+ if (!node)
+ return -ENOMEM;
+ node->ctx = ctx;
+ node->task = current;
+
+ ret = xa_err(xa_store(&tctx->xa, (unsigned long)ctx,
+ node, GFP_KERNEL));
+ if (ret) {
+ kfree(node);
+ return ret;
+ }
+
+ mutex_lock(&ctx->tctx_lock);
+ list_add(&node->ctx_node, &ctx->tctx_list);
+ mutex_unlock(&ctx->tctx_lock);
+ return 0;
+}
+
+int __io_uring_add_tctx_node(struct io_ring_ctx *ctx)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ bool new_tctx = false;
+ int ret;
+
+ if (unlikely(!tctx)) {
+ tctx = io_uring_alloc_task_context(current, ctx);
+ if (IS_ERR(tctx))
+ return PTR_ERR(tctx);
+ new_tctx = true;
+
+ if (data_race(ctx->int_flags) & IO_RING_F_IOWQ_LIMITS_SET) {
+ unsigned int limits[2];
+
+ mutex_lock(&ctx->uring_lock);
+ limits[0] = ctx->iowq_limits[0];
+ limits[1] = ctx->iowq_limits[1];
+ mutex_unlock(&ctx->uring_lock);
+
+ ret = io_wq_max_workers(tctx->io_wq, limits);
+ if (ret)
+ goto err_free;
+ }
+ }
+
+ /*
+ * Re-activate io-wq keepalive on any new io_uring usage. The wq may have
+ * been marked for idle-exit when the task temporarily had no active
+ * io_uring instances.
+ */
+ if (tctx->io_wq)
+ io_wq_set_exit_on_idle(tctx->io_wq, false);
+
+ if (new_tctx)
+ current->io_uring = tctx;
+
+ ret = io_tctx_install_node(ctx, tctx);
+ if (!ret)
+ return 0;
+err_free:
+ if (new_tctx) {
+ current->io_uring = NULL;
+ if (tctx->io_wq) {
+ io_wq_exit_start(tctx->io_wq);
+ io_wq_put_and_exit(tctx->io_wq);
+ }
+ percpu_counter_destroy(&tctx->inflight);
+ kfree(tctx);
+ }
+ return ret;
+}
+
+int __io_uring_add_tctx_node_from_submit(struct io_ring_ctx *ctx)
+{
+ int ret;
+
+ if (ctx->flags & IORING_SETUP_SINGLE_ISSUER
+ && ctx->submitter_task != current)
+ return -EEXIST;
+
+ ret = __io_uring_add_tctx_node(ctx);
+ if (ret)
+ return ret;
+
+ current->io_uring->last = ctx;
+ return 0;
+}
+
+/*
+ * Remove this io_uring_file -> task mapping.
+ */
+__cold void io_uring_del_tctx_node(unsigned long index)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ struct io_tctx_node *node;
+
+ if (!tctx)
+ return;
+ node = xa_erase(&tctx->xa, index);
+ if (!node)
+ return;
+
+ WARN_ON_ONCE(current != node->task);
+ WARN_ON_ONCE(list_empty(&node->ctx_node));
+
+ mutex_lock(&node->ctx->tctx_lock);
+ list_del(&node->ctx_node);
+ mutex_unlock(&node->ctx->tctx_lock);
+
+ if (tctx->last == node->ctx)
+ tctx->last = NULL;
+ kfree(node);
+
+ if (xa_empty(&tctx->xa) && tctx->io_wq)
+ io_wq_set_exit_on_idle(tctx->io_wq, true);
+}
+
+__cold void io_uring_clean_tctx(struct io_uring_task *tctx)
+{
+ struct io_wq *wq = tctx->io_wq;
+ struct io_tctx_node *node;
+ unsigned long index;
+
+ xa_for_each(&tctx->xa, index, node) {
+ io_uring_del_tctx_node(index);
+ cond_resched();
+ }
+ if (wq) {
+ /*
+ * Must be after io_uring_del_tctx_node() (removes nodes under
+ * uring_lock) to avoid race with io_uring_try_cancel_iowq().
+ */
+ io_wq_put_and_exit(wq);
+ tctx->io_wq = NULL;
+ }
+}
+
+void io_uring_unreg_ringfd(void)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ int i;
+
+ for (i = 0; i < IO_RINGFD_REG_MAX; i++) {
+ if (tctx->registered_rings[i]) {
+ fput(tctx->registered_rings[i]);
+ tctx->registered_rings[i] = NULL;
+ }
+ }
+}
+
+int io_ring_add_registered_file(struct io_uring_task *tctx, struct file *file,
+ int start, int end)
+{
+ int offset, idx;
+ for (offset = start; offset < end; offset++) {
+ idx = array_index_nospec(offset, IO_RINGFD_REG_MAX);
+ if (tctx->registered_rings[idx])
+ continue;
+
+ tctx->registered_rings[idx] = file;
+ return idx;
+ }
+ return -EBUSY;
+}
+
+static int io_ring_add_registered_fd(struct io_uring_task *tctx, int fd,
+ int start, int end)
+{
+ struct file *file;
+ int offset;
+
+ file = fget(fd);
+ if (!file) {
+ return -EBADF;
+ } else if (!io_is_uring_fops(file)) {
+ fput(file);
+ return -EOPNOTSUPP;
+ }
+ offset = io_ring_add_registered_file(tctx, file, start, end);
+ if (offset < 0)
+ fput(file);
+ return offset;
+}
+
+/*
+ * Register a ring fd to avoid fdget/fdput for each io_uring_enter()
+ * invocation. User passes in an array of struct io_uring_rsrc_update
+ * with ->data set to the ring_fd, and ->offset given for the desired
+ * index. If no index is desired, application may set ->offset == -1U
+ * and we'll find an available index. Returns number of entries
+ * successfully processed, or < 0 on error if none were processed.
+ */
+int io_ringfd_register(struct io_ring_ctx *ctx, void __user *__arg,
+ unsigned nr_args)
+{
+ struct io_uring_rsrc_update __user *arg = __arg;
+ struct io_uring_rsrc_update reg;
+ struct io_uring_task *tctx;
+ int ret, i;
+
+ if (!nr_args || nr_args > IO_RINGFD_REG_MAX)
+ return -EINVAL;
+
+ mutex_unlock(&ctx->uring_lock);
+ ret = __io_uring_add_tctx_node(ctx);
+ mutex_lock(&ctx->uring_lock);
+ if (ret)
+ return ret;
+
+ tctx = current->io_uring;
+ for (i = 0; i < nr_args; i++) {
+ int start, end;
+
+ if (copy_from_user(&reg, &arg[i], sizeof(reg))) {
+ ret = -EFAULT;
+ break;
+ }
+
+ if (reg.resv) {
+ ret = -EINVAL;
+ break;
+ }
+
+ if (reg.offset == -1U) {
+ start = 0;
+ end = IO_RINGFD_REG_MAX;
+ } else {
+ if (reg.offset >= IO_RINGFD_REG_MAX) {
+ ret = -EINVAL;
+ break;
+ }
+ start = reg.offset;
+ end = start + 1;
+ }
+
+ ret = io_ring_add_registered_fd(tctx, reg.data, start, end);
+ if (ret < 0)
+ break;
+
+ reg.offset = ret;
+ if (copy_to_user(&arg[i], &reg, sizeof(reg))) {
+ fput(tctx->registered_rings[reg.offset]);
+ tctx->registered_rings[reg.offset] = NULL;
+ ret = -EFAULT;
+ break;
+ }
+ }
+
+ return i ? i : ret;
+}
+
+int io_ringfd_unregister(struct io_ring_ctx *ctx, void __user *__arg,
+ unsigned nr_args)
+{
+ struct io_uring_rsrc_update __user *arg = __arg;
+ struct io_uring_task *tctx = current->io_uring;
+ struct io_uring_rsrc_update reg;
+ int ret = 0, i;
+
+ if (!nr_args || nr_args > IO_RINGFD_REG_MAX)
+ return -EINVAL;
+ if (!tctx)
+ return 0;
+
+ for (i = 0; i < nr_args; i++) {
+ if (copy_from_user(&reg, &arg[i], sizeof(reg))) {
+ ret = -EFAULT;
+ break;
+ }
+ if (reg.resv || reg.data || reg.offset >= IO_RINGFD_REG_MAX) {
+ ret = -EINVAL;
+ break;
+ }
+
+ reg.offset = array_index_nospec(reg.offset, IO_RINGFD_REG_MAX);
+ if (tctx->registered_rings[reg.offset]) {
+ fput(tctx->registered_rings[reg.offset]);
+ tctx->registered_rings[reg.offset] = NULL;
+ }
+ }
+
+ return i ? i : ret;
+}
+
+int __io_uring_fork(struct task_struct *tsk)
+{
+ struct io_restriction *res, *src = tsk->io_uring_restrict;
+
+ /* Don't leave it dangling on error */
+ tsk->io_uring_restrict = NULL;
+
+ res = kzalloc_obj(*res, GFP_KERNEL_ACCOUNT);
+ if (!res)
+ return -ENOMEM;
+
+ tsk->io_uring_restrict = res;
+ io_restriction_clone(res, src);
+ return 0;
+}