remoteproc: core: Remove casting to rproc_handle_resource_t

There are four different callback functions that are used for the
rproc_handle_resource_t callback that all have different second
parameter types.

rproc_handle_vdev -> struct fw_rsc_vdev
rproc_handle_trace -> struct fw_rsc_trace
rproc_handle_devmem -> struct fw_rsc_devmem
rproc_handle_carveout -> struct fw_rsc_carveout

These callbacks are cast to rproc_handle_resource_t so that there is no
error about incompatible pointer types. Unfortunately, this is a Clang's
Control-Flow Integrity checking violation, which verifies that the
callback function's types match the prototypes exactly before jumping.

[    7.275750] Kernel panic - not syncing: CFI failure (target: rproc_handle_vdev+0x0/0x4)
[    7.283763] CPU: 2 PID: 1 Comm: init Tainted: G         C O      5.4.70-03301-g527af2c96672 #17
[    7.292463] Hardware name: NXP i.MX8MPlus EVK board (DT)
[    7.297779] Call trace:
[    7.300232]  dump_backtrace.cfi_jt+0x0/0x4
[    7.304337]  show_stack+0x18/0x24
[    7.307660]  dump_stack+0xb8/0x114
[    7.311069]  panic+0x164/0x3d4
[    7.314130]  __ubsan_handle_cfi_check_fail_abort+0x0/0x14
[    7.319533]  perf_proc_update_handler+0x0/0xcc
[    7.323983]  __cfi_check+0x63278/0x6a290
[    7.327913]  rproc_boot+0x3f8/0x738
[    7.331404]  rproc_add+0x68/0x110
[    7.334738]  imx_rproc_probe+0x5e4/0x708 [imx_rproc]
[    7.339711]  platform_drv_probe+0xac/0xf0
[    7.343726]  really_probe+0x260/0x65c
[    7.347393]  driver_probe_device+0x64/0x100
[    7.351580]  device_driver_attach+0x6c/0xac
[    7.355766]  __driver_attach+0xdc/0x184
[    7.359609]  bus_for_each_dev+0x98/0x104
[    7.363537]  driver_attach+0x24/0x30
[    7.367117]  bus_add_driver+0x100/0x1e0
[    7.370958]  driver_register+0x78/0x114
[    7.374800]  __platform_driver_register+0x44/0x50
[    7.379514]  init_module+0x20/0xfe8 [imx_rproc]
[    7.384049]  do_one_initcall+0x190/0x348
[    7.387979]  do_init_module+0x5c/0x210
[    7.391731]  load_module+0x2fbc/0x3590
[    7.395485]  __arm64_sys_finit_module+0xb8/0xec
[    7.400025]  el0_svc_common+0xb4/0x19c
[    7.403777]  el0_svc_handler+0x74/0x98
[    7.407531]  el0_svc+0x8/0xc
[    7.410419] SMP: stopping secondary CPUs
[    7.414648] Kernel Offset: disabled
[    7.418142] CPU features: 0x00010002,2000200c
[    7.422501] Memory Limit: none

To fix this, change the second parameter of all functions to void * and
use a local variable with the correct type so that everything works
properly. With this, we can remove casting to rproc_handle_resource_t
for these functions.
Signed-off-by: Jindong Yue <jindong.yue@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210224055825.7417-1-jindong.yue@nxp.comSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/remoteproc_core.c

@@ -482,7 +482,7 @@ static int copy_dma_range_map(struct device *to, struct device *from)
 /**
  * rproc_handle_vdev() - handle a vdev fw resource
  * @rproc: the remote processor
- * @rsc: the vring resource descriptor
+ * @ptr: the vring resource descriptor
  * @offset: offset of the resource entry
  * @avail: size of available data (for sanity checking the image)
  *
@@ -507,9 +507,10 @@ static int copy_dma_range_map(struct device *to, struct device *from)
  *
  * Returns 0 on success, or an appropriate error code otherwise
  */
-static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
+static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
 			     int offset, int avail)
 {
+	struct fw_rsc_vdev *rsc = ptr;
 	struct device *dev = &rproc->dev;
 	struct rproc_vdev *rvdev;
 	int i, ret;
@@ -627,7 +628,7 @@ void rproc_vdev_release(struct kref *ref)
 /**
  * rproc_handle_trace() - handle a shared trace buffer resource
  * @rproc: the remote processor
- * @rsc: the trace resource descriptor
+ * @ptr: the trace resource descriptor
  * @offset: offset of the resource entry
  * @avail: size of available data (for sanity checking the image)
  *
@@ -641,9 +642,10 @@ void rproc_vdev_release(struct kref *ref)
  *
  * Returns 0 on success, or an appropriate error code otherwise
  */
-static int rproc_handle_trace(struct rproc *rproc, struct fw_rsc_trace *rsc,
+static int rproc_handle_trace(struct rproc *rproc, void *ptr,
 			      int offset, int avail)
 {
+	struct fw_rsc_trace *rsc = ptr;
 	struct rproc_debug_trace *trace;
 	struct device *dev = &rproc->dev;
 	char name[15];
@@ -693,7 +695,7 @@ static int rproc_handle_trace(struct rproc *rproc, struct fw_rsc_trace *rsc,
 /**
  * rproc_handle_devmem() - handle devmem resource entry
  * @rproc: remote processor handle
- * @rsc: the devmem resource entry
+ * @ptr: the devmem resource entry
  * @offset: offset of the resource entry
  * @avail: size of available data (for sanity checking the image)
  *
@@ -716,9 +718,10 @@ static int rproc_handle_trace(struct rproc *rproc, struct fw_rsc_trace *rsc,
  * and not allow firmwares to request access to physical addresses that
  * are outside those ranges.
  */
-static int rproc_handle_devmem(struct rproc *rproc, struct fw_rsc_devmem *rsc,
+static int rproc_handle_devmem(struct rproc *rproc, void *ptr,
 			       int offset, int avail)
 {
+	struct fw_rsc_devmem *rsc = ptr;
 	struct rproc_mem_entry *mapping;
 	struct device *dev = &rproc->dev;
 	int ret;
@@ -896,7 +899,7 @@ static int rproc_release_carveout(struct rproc *rproc,
 /**
  * rproc_handle_carveout() - handle phys contig memory allocation requests
  * @rproc: rproc handle
- * @rsc: the resource entry
+ * @ptr: the resource entry
  * @offset: offset of the resource entry
  * @avail: size of available data (for image validation)
  *
@@ -913,9 +916,9 @@ static int rproc_release_carveout(struct rproc *rproc,
  * pressure is important; it may have a substantial impact on performance.
  */
 static int rproc_handle_carveout(struct rproc *rproc,
-				 struct fw_rsc_carveout *rsc,
-				 int offset, int avail)
+				 void *ptr, int offset, int avail)
 {
+	struct fw_rsc_carveout *rsc = ptr;
 	struct rproc_mem_entry *carveout;
 	struct device *dev = &rproc->dev;
 
@@ -1097,10 +1100,10 @@ EXPORT_SYMBOL(rproc_of_parse_firmware);
  * enum fw_resource_type.
  */
 static rproc_handle_resource_t rproc_loading_handlers[RSC_LAST] = {
-	[RSC_CARVEOUT] = (rproc_handle_resource_t)rproc_handle_carveout,
-	[RSC_DEVMEM] = (rproc_handle_resource_t)rproc_handle_devmem,
-	[RSC_TRACE] = (rproc_handle_resource_t)rproc_handle_trace,
-	[RSC_VDEV] = (rproc_handle_resource_t)rproc_handle_vdev,
+	[RSC_CARVEOUT] = rproc_handle_carveout,
+	[RSC_DEVMEM] = rproc_handle_devmem,
+	[RSC_TRACE] = rproc_handle_trace,
+	[RSC_VDEV] = rproc_handle_vdev,
 };
 
 /* handle firmware resource entries before booting the remote processor */