[xen staging] xen/arm: optee: Add MISRA-compliant switch default labels

[patchbot@xxxxxxx]

commit 4fb391500430aceb97b2367c246d4a68fe6ae13e
Author:     Bertrand Marquis <bertrand.marquis@xxxxxxx>
AuthorDate: Fri Mar 20 10:07:22 2026 +0100
Commit:     Michal Orzel <michal.orzel@xxxxxxx>
CommitDate: Tue Mar 31 11:01:12 2026 +0200

    xen/arm: optee: Add MISRA-compliant switch default labels
    
    optee.c has several switch statements over integer-valued OP-TEE fields
    without a default label, and two default clauses that only contain
    break. This triggers MISRA C Rule 16.4 findings.
    
    Add explicit default labels to all reported switches and document the
    intentional no-op defaults with rationale comments. The new default
    paths preserve the existing behavior:
    - unsupported parameter attribute types are ignored;
    - non-handled RPC commands require no post-processing in Xen;
    - unknown RPC function IDs are resumed unchanged.
    
    No functional changes.
    
    Signed-off-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
    Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
    Reviewed-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
---
 xen/arch/arm/tee/optee.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/xen/arch/arm/tee/optee.c b/xen/arch/arm/tee/optee.c
index f719d9d767..3d26332370 100644
--- a/xen/arch/arm/tee/optee.c
+++ b/xen/arch/arm/tee/optee.c
@@ -897,6 +897,9 @@ static int translate_params(struct optee_domain *ctx,
         case OPTEE_MSG_ATTR_TYPE_RMEM_OUTPUT:
         case OPTEE_MSG_ATTR_TYPE_RMEM_INOUT:
             continue;
+        default:
+            /* Ignore unsupported parameter type. */
+            continue;
         }
     }
 
@@ -1027,6 +1030,9 @@ static void copy_std_request_back(struct optee_domain 
*ctx,
         case OPTEE_MSG_ATTR_TYPE_RMEM_INPUT:
         case OPTEE_MSG_ATTR_TYPE_TMEM_INPUT:
             continue;
+        default:
+            /* No output fields to copy for unsupported parameter type. */
+            continue;
         }
     }
 
@@ -1050,6 +1056,7 @@ static void free_shm_buffers(struct optee_domain *ctx,
             free_optee_shm_buf(ctx, arg->params[i].u.tmem.shm_ref);
             break;
         default:
+            /* No temporary SHM buffer to free for other parameter types. */
             break;
         }
     }
@@ -1503,6 +1510,7 @@ static void handle_rpc_cmd(struct optee_domain *ctx, 
struct cpu_user_regs *regs,
         case OPTEE_RPC_CMD_SHM_FREE:
             break;
         default:
+            /* Other RPC commands need no Xen-side post-processing here. */
             break;
         }
     }
@@ -1591,6 +1599,9 @@ static void handle_rpc(struct optee_domain *ctx, struct 
cpu_user_regs *regs)
     case OPTEE_SMC_RPC_FUNC_CMD:
         handle_rpc_cmd(ctx, regs, call);
         return;
+    default:
+        /* Resume the call unchanged for unknown RPC function IDs. */
+        break;
     }
 
     do_call_with_arg(ctx, call, regs, OPTEE_SMC_CALL_RETURN_FROM_RPC,
--
generated by git-patchbot for /home/xen/git/xen.git#staging