staging: unisys: Change data to point to visor_controlvm_parameters_header.

The data field was being defined as a character array and then casted into
a visor_controlvm_parameters_header structure. This patch converts it to
just point to the visor_controlvm_parameters_header structure. The data
following the header is still behind the header_info.

Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/unisys/visorbus/visorchipset.c b/drivers/staging/unisys/visorbus/visorchipset.c
index 3a8357e07377737c904992dcf0e7ff0504f8d12a..d27e0e897ab92e519a5d404da5e0b70502b369f5 100644 (file)
--- a/drivers/staging/unisys/visorbus/visorchipset.c
+++ b/drivers/staging/unisys/visorbus/visorchipset.c
@@ -53,7 +53,7 @@ struct parser_context {
        u8 *curr;
        unsigned long bytes_remaining;
        bool byte_stream;
-       char data[0];
+       struct visor_controlvm_parameters_header data;
 };
 
 /* VMCALL_CONTROLVM_ADDR: Used by all guests, not just IO. */
@@ -299,10 +299,7 @@ static DEVICE_ATTR_RW(remaining_steps);
 
 static const guid_t *parser_id_get(struct parser_context *ctx)
 {
-       struct visor_controlvm_parameters_header *phdr = NULL;
-
-       phdr = (struct visor_controlvm_parameters_header *)(ctx->data);
-       return &phdr->id;
+       return &ctx->data.id;
 }
 
 static void parser_done(struct parser_context *ctx)
@@ -348,12 +345,12 @@ static void *parser_name_get(struct parser_context *ctx)
 {
        struct visor_controlvm_parameters_header *phdr = NULL;
 
-       phdr = (struct visor_controlvm_parameters_header *)(ctx->data);
+       phdr = &ctx->data;
 
        if (phdr->name_offset + phdr->name_length > ctx->param_bytes)
                return NULL;
 
-       ctx->curr = ctx->data + phdr->name_offset;
+       ctx->curr = (char *)&phdr + phdr->name_offset;
        ctx->bytes_remaining = phdr->name_length;
        return parser_string_get(ctx);
 }
@@ -1455,17 +1452,15 @@ void visorbus_device_changestate_response(struct visor_device *dev_info,
 static struct parser_context *parser_init_byte_stream(u64 addr, u32 bytes,
                                                      bool *retry)
 {
-       int allocbytes = sizeof(struct parser_context) + bytes;
+       int allocbytes;
        struct parser_context *ctx;
        void *mapping;
 
        *retry = false;
 
-       /*
-        * alloc an 0 extra byte to ensure payload is
-        * '\0'-terminated
-        */
-       allocbytes++;
+       /* alloc an extra byte to ensure payload is \0 terminated */
+       allocbytes = bytes + 1 + (sizeof(struct parser_context) -
+                    sizeof(struct visor_controlvm_parameters_header));
        if ((chipset_dev->controlvm_payload_bytes_buffered + bytes)
            > MAX_CONTROLVM_PAYLOAD_BYTES) {
                *retry = true;
@@ -1482,7 +1477,7 @@ static struct parser_context *parser_init_byte_stream(u64 addr, u32 bytes,
        mapping = memremap(addr, bytes, MEMREMAP_WB);
        if (!mapping)
                goto err_finish_ctx;
-       memcpy(ctx->data, mapping, bytes);
+       memcpy(&ctx->data, mapping, bytes);
        memunmap(mapping);
        ctx->byte_stream = true;
        chipset_dev->controlvm_payload_bytes_buffered += ctx->param_bytes;