netdev - [PATCH v4 2/8] io_uring/memmap: refactor io_free_region() to take user

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Message-ID: <20251028174639.1244592-3-dw@davidwei.uk>
Date: Tue, 28 Oct 2025 10:46:33 -0700
From: David Wei <dw@...idwei.uk>
To: io-uring@...r.kernel.org,
	netdev@...r.kernel.org
Cc: Jens Axboe <axboe@...nel.dk>,
	Pavel Begunkov <asml.silence@...il.com>
Subject: [PATCH v4 2/8] io_uring/memmap: refactor io_free_region() to take user_struct param

Refactor io_free_region() to take user_struct directly, instead of
accessing it from the ring ctx.

Signed-off-by: David Wei <dw@...idwei.uk>
---
 io_uring/io_uring.c | 6 +++---
 io_uring/kbuf.c     | 4 ++--
 io_uring/memmap.c   | 8 ++++----
 io_uring/memmap.h   | 2 +-
 io_uring/register.c | 6 +++---
 io_uring/zcrx.c     | 2 +-
 6 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 200b6c4bb2cc..7d42748774f8 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2798,8 +2798,8 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, u32 flags,
 
 static void io_rings_free(struct io_ring_ctx *ctx)
 {
-	io_free_region(ctx, &ctx->sq_region);
-	io_free_region(ctx, &ctx->ring_region);
+	io_free_region(ctx->user, &ctx->sq_region);
+	io_free_region(ctx->user, &ctx->ring_region);
 	ctx->rings = NULL;
 	ctx->sq_sqes = NULL;
 }
@@ -2884,7 +2884,7 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
 	io_eventfd_unregister(ctx);
 	io_free_alloc_caches(ctx);
 	io_destroy_buffers(ctx);
-	io_free_region(ctx, &ctx->param_region);
+	io_free_region(ctx->user, &ctx->param_region);
 	mutex_unlock(&ctx->uring_lock);
 	if (ctx->sq_creds)
 		put_cred(ctx->sq_creds);
diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
index c034c90396bc..8a329556f8df 100644
--- a/io_uring/kbuf.c
+++ b/io_uring/kbuf.c
@@ -428,7 +428,7 @@ static int io_remove_buffers_legacy(struct io_ring_ctx *ctx,
 static void io_put_bl(struct io_ring_ctx *ctx, struct io_buffer_list *bl)
 {
 	if (bl->flags & IOBL_BUF_RING)
-		io_free_region(ctx, &bl->region);
+		io_free_region(ctx->user, &bl->region);
 	else
 		io_remove_buffers_legacy(ctx, bl, -1U);
 
@@ -672,7 +672,7 @@ int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
 	io_buffer_add_list(ctx, bl, reg.bgid);
 	return 0;
 fail:
-	io_free_region(ctx, &bl->region);
+	io_free_region(ctx->user, &bl->region);
 	kfree(bl);
 	return ret;
 }
diff --git a/io_uring/memmap.c b/io_uring/memmap.c
index d1318079c337..b1054fe94568 100644
--- a/io_uring/memmap.c
+++ b/io_uring/memmap.c
@@ -88,7 +88,7 @@ enum {
 	IO_REGION_F_SINGLE_REF			= 4,
 };
 
-void io_free_region(struct io_ring_ctx *ctx, struct io_mapped_region *mr)
+void io_free_region(struct user_struct *user, struct io_mapped_region *mr)
 {
 	if (mr->pages) {
 		long nr_refs = mr->nr_pages;
@@ -105,8 +105,8 @@ void io_free_region(struct io_ring_ctx *ctx, struct io_mapped_region *mr)
 	}
 	if ((mr->flags & IO_REGION_F_VMAP) && mr->ptr)
 		vunmap(mr->ptr);
-	if (mr->nr_pages && ctx->user)
-		__io_unaccount_mem(ctx->user, mr->nr_pages);
+	if (mr->nr_pages && user)
+		__io_unaccount_mem(user, mr->nr_pages);
 
 	memset(mr, 0, sizeof(*mr));
 }
@@ -228,7 +228,7 @@ int io_create_region(struct io_ring_ctx *ctx, struct io_mapped_region *mr,
 		goto out_free;
 	return 0;
 out_free:
-	io_free_region(ctx, mr);
+	io_free_region(ctx->user, mr);
 	return ret;
 }
 
diff --git a/io_uring/memmap.h b/io_uring/memmap.h
index 58002976e0c3..a7c476f499d5 100644
--- a/io_uring/memmap.h
+++ b/io_uring/memmap.h
@@ -16,7 +16,7 @@ unsigned long io_uring_get_unmapped_area(struct file *file, unsigned long addr,
 					 unsigned long flags);
 int io_uring_mmap(struct file *file, struct vm_area_struct *vma);
 
-void io_free_region(struct io_ring_ctx *ctx, struct io_mapped_region *mr);
+void io_free_region(struct user_struct *user, struct io_mapped_region *mr);
 int io_create_region(struct io_ring_ctx *ctx, struct io_mapped_region *mr,
 		     struct io_uring_region_desc *reg,
 		     unsigned long mmap_offset);
diff --git a/io_uring/register.c b/io_uring/register.c
index 1a3e05be6e7b..023f5e7a18da 100644
--- a/io_uring/register.c
+++ b/io_uring/register.c
@@ -381,8 +381,8 @@ struct io_ring_ctx_rings {
 static void io_register_free_rings(struct io_ring_ctx *ctx,
 				   struct io_ring_ctx_rings *r)
 {
-	io_free_region(ctx, &r->sq_region);
-	io_free_region(ctx, &r->ring_region);
+	io_free_region(ctx->user, &r->sq_region);
+	io_free_region(ctx->user, &r->ring_region);
 }
 
 #define swap_old(ctx, o, n, field)		\
@@ -604,7 +604,7 @@ static int io_register_mem_region(struct io_ring_ctx *ctx, void __user *uarg)
 	if (ret)
 		return ret;
 	if (copy_to_user(rd_uptr, &rd, sizeof(rd))) {
-		io_free_region(ctx, &region);
+		io_free_region(ctx->user, &region);
 		return -EFAULT;
 	}
 
diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
index a816f5902091..d15453884004 100644
--- a/io_uring/zcrx.c
+++ b/io_uring/zcrx.c
@@ -378,7 +378,7 @@ static int io_allocate_rbuf_ring(struct io_zcrx_ifq *ifq,
 
 static void io_free_rbuf_ring(struct io_zcrx_ifq *ifq)
 {
-	io_free_region(ifq->ctx, &ifq->region);
+	io_free_region(ifq->ctx->user, &ifq->region);
 	ifq->rq_ring = NULL;
 	ifq->rqes = NULL;
 }
-- 
2.47.3