Fixed coverity issue in acl_kernel_if.cpp: Type: Reliance on integer endianness (INCOMPATIBLE_CAST)

In the three instances where this issue happens, the function acl_kernel_if_read_32b is used at the end of the scope to query about what's inside the acl_kernel_if* kern object. However, they don't do anything with the obtained information. I believe this read operation is performed to confirm that the acl_kernel_if* kern has been written properly. So if the read operation successed, then the write operation must have also succeeded as well. Therefore, instead of type-punning casting to pass an existing variable, I created a new dummy variable with the only purpose for the read operation to confirm that the read is correct.

Author: haoxian2

src/acl_kernel_if.cpp

@@ -3,12 +3,12 @@
 
 // System headers.
 #include <cassert>
+#include <cinttypes>
 #include <cstdint>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string>
 #include <vector>
-#include <cinttypes>
 
 // Internal headers.
 #include <acl_auto_configure.h>
@@ -289,8 +289,8 @@ static int acl_kernel_if_read_32b(acl_kernel_if *kern, unsigned int addr,
   r = kern->io.read(&kern->io, (dev_addr_t)addr, (char *)val, (size_t)size);
   if (r < size) {
     kern->io.printf(
-        "HAL Kern Error: Read failed from addr %x, read %zu expected %zu\n", addr,
-        r, size);
+        "HAL Kern Error: Read failed from addr %x, read %zu expected %zu\n",
+        addr, r, size);
     return -1;
   }
   return 0;
@@ -335,8 +335,8 @@ static int acl_kernel_rom_read_block(acl_kernel_if *kern, unsigned int addr,
   r = kern->io.read(&kern->io, (dev_addr_t)addr, config_rom, (size_t)size);
   if (r < size) {
     kern->io.printf(
-        "HAL Kern Error: Read failed from addr %x, read %zu expected %zu\n", addr,
-        r, size);
+        "HAL Kern Error: Read failed from addr %x, read %zu expected %zu\n",
+        addr, r, size);
     return -1;
   }
   return 0;
@@ -382,9 +382,10 @@ static int acl_kernel_if_write_64b(acl_kernel_if *kern, unsigned int addr,
   r = (int)kern->io.write(&kern->io, (dev_addr_t)addr, (char *)&val,
                           (size_t)size);
   if (r < size) {
-    kern->io.printf("HAL Kern Error: Write failed to addr %x with value %" PRIu64 ", "
-                    "wrote %d, expected %d\n",
-                    addr, val, r, size);
+    kern->io.printf(
+        "HAL Kern Error: Write failed to addr %x with value %" PRIu64 ", "
+        "wrote %d, expected %d\n",
+        addr, val, r, size);
     return -1;
   }
   return 0;
@@ -452,8 +453,8 @@ static uintptr_t acl_kernel_cra_set_segment(acl_kernel_if *kern,
     acl_kernel_if_write_32b(kern, OFFSET_KERNEL_CRA_SEGMENT,
                             (unsigned int)segment);
     kern->cur_segment = segment;
-    acl_kernel_if_read_32b(kern, OFFSET_KERNEL_CRA_SEGMENT,
-                           (unsigned int *)&segment);
+    unsigned int new_segment;
+    acl_kernel_if_read_32b(kern, OFFSET_KERNEL_CRA_SEGMENT, &new_segment);
   }
 
   return segment_offset;
@@ -469,8 +470,8 @@ static uintptr_t acl_kernel_cra_set_segment_rom(acl_kernel_if *kern,
     acl_kernel_if_write_32b(kern, OFFSET_KERNEL_CRA_SEGMENT,
                             (unsigned int)segment);
     kern->cur_segment = segment;
-    acl_kernel_if_read_32b(kern, OFFSET_KERNEL_CRA_SEGMENT,
-                           (unsigned int *)&segment);
+    unsigned int new_segment;
+    acl_kernel_if_read_32b(kern, OFFSET_KERNEL_CRA_SEGMENT, &new_segment);
   }
 
   return segment_offset;
@@ -931,10 +932,10 @@ int acl_kernel_if_update(const acl_device_def_autodiscovery_t &devdef,
           OFFSET_KERNEL_CRA + devdef.hal_info[ii].csr.address;
       kern->accel_csr[ii].bytes = devdef.hal_info[ii].csr.num_bytes;
 
-      ACL_KERNEL_IF_DEBUG_MSG(kern, "Kernel_%s CSR { 0x%08" PRIuPTR ", 0x%08" PRIuPTR " }\n",
-                              devdef.accel[ii].iface.name.c_str(),
-                              kern->accel_csr[ii].address,
-                              kern->accel_csr[ii].bytes);
+      ACL_KERNEL_IF_DEBUG_MSG(
+          kern, "Kernel_%s CSR { 0x%08" PRIuPTR ", 0x%08" PRIuPTR " }\n",
+          devdef.accel[ii].iface.name.c_str(), kern->accel_csr[ii].address,
+          kern->accel_csr[ii].bytes);
     }
 
     // The Kernel performance monitor registers
@@ -943,10 +944,10 @@ int acl_kernel_if_update(const acl_device_def_autodiscovery_t &devdef,
           OFFSET_KERNEL_CRA + devdef.hal_info[ii].perf_mon.address;
       kern->accel_perf_mon[ii].bytes = devdef.hal_info[ii].perf_mon.num_bytes;
 
-      ACL_KERNEL_IF_DEBUG_MSG(kern, "Kernel_%s perf_mon { 0x%08" PRIuPTR ", 0x%08" PRIuPTR " }\n",
-                              devdef.accel[ii].iface.name.c_str(),
-                              kern->accel_perf_mon[ii].address,
-                              kern->accel_perf_mon[ii].bytes);
+      ACL_KERNEL_IF_DEBUG_MSG(
+          kern, "Kernel_%s perf_mon { 0x%08" PRIuPTR ", 0x%08" PRIuPTR " }\n",
+          devdef.accel[ii].iface.name.c_str(), kern->accel_perf_mon[ii].address,
+          kern->accel_perf_mon[ii].bytes);
 
       // printf info
       kern->accel_num_printfs[ii] =
@@ -1614,8 +1615,9 @@ void acl_kernel_if_update_status(acl_kernel_if *kern) {
     acl_kernel_if_write_32b(kern, OFFSET_KERNEL_CRA_SEGMENT,
                             (unsigned int)segment_pre_irq);
     kern->cur_segment = segment_pre_irq;
+    unsigned int new_segment_pre_irq;
     acl_kernel_if_read_32b(kern, OFFSET_KERNEL_CRA_SEGMENT,
-                           (unsigned int *)&segment_pre_irq);
+                           &new_segment_pre_irq);
   }
 }