bus: mhi: host: Use kzalloc_flex

Change kzalloc + kzalloc to just kzalloc with a flexible array member.

Add __counted_by for extra runtime analysis when requested.

Move counting assignment immediately after allocation as required by
__counted_by.

Move mhi_buf definition as a complete definition as needed for flex
arrays. It's not a pointer anymore.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
[mani: squashed https://lore.kernel.org/mhi/20260317-mhi-invalid-free-mhi-buffers-v1-1-8418a3ad604f@oss.qualcomm.com]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Link: https://patch.msgid.link/20260312045921.7663-1-rosenp@gmail.com

diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c
index f16a1e67a667d6b2d355df25d8c038825cef9e02..19c84913cfb959a6fd1b1b47b33d691a8bb1c6a6 100644 (file)
--- a/drivers/bus/mhi/host/boot.c
+++ b/drivers/bus/mhi/host/boot.c
@@ -308,7 +308,6 @@ static void mhi_free_bhi_buffer(struct mhi_controller *mhi_cntrl,
        struct mhi_buf *mhi_buf = image_info->mhi_buf;
 
        dma_free_coherent(mhi_cntrl->cntrl_dev, mhi_buf->len, mhi_buf->buf, mhi_buf->dma_addr);
-       kfree(image_info->mhi_buf);
        kfree(image_info);
 }
 
@@ -322,7 +321,6 @@ void mhi_free_bhie_table(struct mhi_controller *mhi_cntrl,
                dma_free_coherent(mhi_cntrl->cntrl_dev, mhi_buf->len,
                                  mhi_buf->buf, mhi_buf->dma_addr);
 
-       kfree(image_info->mhi_buf);
        kfree(image_info);
 }
 
@@ -333,15 +331,10 @@ static int mhi_alloc_bhi_buffer(struct mhi_controller *mhi_cntrl,
        struct image_info *img_info;
        struct mhi_buf *mhi_buf;
 
-       img_info = kzalloc_obj(*img_info);
+       img_info = kzalloc_flex(*img_info, mhi_buf, 1);
        if (!img_info)
                return -ENOMEM;
 
-       /* Allocate memory for entry */
-       img_info->mhi_buf = kzalloc_obj(*img_info->mhi_buf);
-       if (!img_info->mhi_buf)
-               goto error_alloc_mhi_buf;
-
        /* Allocate and populate vector table */
        mhi_buf = img_info->mhi_buf;
 
@@ -358,8 +351,6 @@ static int mhi_alloc_bhi_buffer(struct mhi_controller *mhi_cntrl,
        return 0;
 
 error_alloc_segment:
-       kfree(mhi_buf);
-error_alloc_mhi_buf:
        kfree(img_info);
 
        return -ENOMEM;
@@ -375,14 +366,11 @@ int mhi_alloc_bhie_table(struct mhi_controller *mhi_cntrl,
        struct image_info *img_info;
        struct mhi_buf *mhi_buf;
 
-       img_info = kzalloc_obj(*img_info);
+       img_info = kzalloc_flex(*img_info, mhi_buf, segments);
        if (!img_info)
                return -ENOMEM;
 
-       /* Allocate memory for entries */
-       img_info->mhi_buf = kzalloc_objs(*img_info->mhi_buf, segments);
-       if (!img_info->mhi_buf)
-               goto error_alloc_mhi_buf;
+       img_info->entries = segments;
 
        /* Allocate and populate vector table */
        mhi_buf = img_info->mhi_buf;
@@ -402,7 +390,6 @@ int mhi_alloc_bhie_table(struct mhi_controller *mhi_cntrl,
        }
 
        img_info->bhi_vec = img_info->mhi_buf[segments - 1].buf;
-       img_info->entries = segments;
        *image_info = img_info;
 
        return 0;
@@ -411,9 +398,6 @@ error_alloc_segment:
        for (--i, --mhi_buf; i >= 0; i--, mhi_buf--)
                dma_free_coherent(mhi_cntrl->cntrl_dev, mhi_buf->len,
                                  mhi_buf->buf, mhi_buf->dma_addr);
-       kfree(img_info->mhi_buf);
-
-error_alloc_mhi_buf:
        kfree(img_info);
 
        return -ENOMEM;

diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 88ccb3e14f481d6b85c2a314eb74ba960c2d4c81..fb3ba639f4f87dbc0f07ab6b68e7ea990fd80091 100644 (file)
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -85,17 +85,33 @@ enum mhi_ch_type {
        MHI_CH_TYPE_INBOUND_COALESCED = 3,
 };
 
+/**
+ * struct mhi_buf - MHI Buffer description
+ * @buf: Virtual address of the buffer
+ * @name: Buffer label. For offload channel, configurations name must be:
+ *        ECA - Event context array data
+ *        CCA - Channel context array data
+ * @dma_addr: IOMMU address of the buffer
+ * @len: # of bytes
+ */
+struct mhi_buf {
+       void *buf;
+       const char *name;
+       dma_addr_t dma_addr;
+       size_t len;
+};
+
 /**
  * struct image_info - Firmware and RDDM table
  * @mhi_buf: Buffer for firmware and RDDM table
  * @entries: # of entries in table
  */
 struct image_info {
-       struct mhi_buf *mhi_buf;
        /* private: from internal.h */
        struct bhi_vec_entry *bhi_vec;
        /* public: */
        u32 entries;
+       struct mhi_buf mhi_buf[] __counted_by(entries);
 };
 
 /**
@@ -488,22 +504,6 @@ struct mhi_result {
        int transaction_status;
 };
 
-/**
- * struct mhi_buf - MHI Buffer description
- * @buf: Virtual address of the buffer
- * @name: Buffer label. For offload channel, configurations name must be:
- *        ECA - Event context array data
- *        CCA - Channel context array data
- * @dma_addr: IOMMU address of the buffer
- * @len: # of bytes
- */
-struct mhi_buf {
-       void *buf;
-       const char *name;
-       dma_addr_t dma_addr;
-       size_t len;
-};
-
 /**
  * struct mhi_driver - Structure representing a MHI client driver
  * @probe: CB function for client driver probe function