x86: mark compat hypercall regs clobbering for intended fall-through

Oddly enough in the original report Coverity only complained about the
native hypercall related switch() statements. Now that it has seen those
fixed, it complains about (only HVM) compat ones. Hence the CIDs below
are all for the HVM side of things, yet while at it take care of the PV
side as well.

Coverity-ID: 1487105, 1487106, 1487107, 1487108, 1487109.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

diff --git a/xen/arch/x86/hvm/hypercall.c b/xen/arch/x86/hvm/hypercall.c
index 263d5407ea2a0782b0ccc5d4dcc8ed6a4c0a2899..261d8ee8a42b488f21e5329d21774389b0ee1559 100644 (file)
--- a/xen/arch/x86/hvm/hypercall.c
+++ b/xen/arch/x86/hvm/hypercall.c
@@ -292,11 +292,11 @@ int hvm_hypercall(struct cpu_user_regs *regs)
         /* Deliberately corrupt parameter regs not used by this hypercall. */
         switch ( hypercall_args_table[eax].compat )
         {
-        case 0: ebx = 0xdeadf00d;
-        case 1: ecx = 0xdeadf00d;
-        case 2: edx = 0xdeadf00d;
-        case 3: esi = 0xdeadf00d;
-        case 4: edi = 0xdeadf00d;
+        case 0: ebx = 0xdeadf00d; fallthrough;
+        case 1: ecx = 0xdeadf00d; fallthrough;
+        case 2: edx = 0xdeadf00d; fallthrough;
+        case 3: esi = 0xdeadf00d; fallthrough;
+        case 4: edi = 0xdeadf00d; fallthrough;
         case 5: ebp = 0xdeadf00d;
         }
 #endif
@@ -312,11 +312,11 @@ int hvm_hypercall(struct cpu_user_regs *regs)
             /* Deliberately corrupt parameter regs used by this hypercall. */
             switch ( hypercall_args_table[eax].compat )
             {
-            case 6: regs->rbp = 0xdeadf00d;
-            case 5: regs->rdi = 0xdeadf00d;
-            case 4: regs->rsi = 0xdeadf00d;
-            case 3: regs->rdx = 0xdeadf00d;
-            case 2: regs->rcx = 0xdeadf00d;
+            case 6: regs->rbp = 0xdeadf00d; fallthrough;
+            case 5: regs->rdi = 0xdeadf00d; fallthrough;
+            case 4: regs->rsi = 0xdeadf00d; fallthrough;
+            case 3: regs->rdx = 0xdeadf00d; fallthrough;
+            case 2: regs->rcx = 0xdeadf00d; fallthrough;
             case 1: regs->rbx = 0xdeadf00d;
             }
         }

diff --git a/xen/arch/x86/pv/hypercall.c b/xen/arch/x86/pv/hypercall.c
index 03939bdfcf152d611573a1e1d574ee11c3c607f2..9765e674cf6058cba4428bc9e98f16f33c03a8ee 100644 (file)
--- a/xen/arch/x86/pv/hypercall.c
+++ b/xen/arch/x86/pv/hypercall.c
@@ -197,11 +197,11 @@ void pv_hypercall(struct cpu_user_regs *regs)
         /* Deliberately corrupt parameter regs not used by this hypercall. */
         switch ( hypercall_args_table[eax].compat )
         {
-        case 0: ebx = 0xdeadf00d;
-        case 1: ecx = 0xdeadf00d;
-        case 2: edx = 0xdeadf00d;
-        case 3: esi = 0xdeadf00d;
-        case 4: edi = 0xdeadf00d;
+        case 0: ebx = 0xdeadf00d; fallthrough;
+        case 1: ecx = 0xdeadf00d; fallthrough;
+        case 2: edx = 0xdeadf00d; fallthrough;
+        case 3: esi = 0xdeadf00d; fallthrough;
+        case 4: edi = 0xdeadf00d; fallthrough;
         case 5: ebp = 0xdeadf00d;
         }
 #endif
@@ -223,11 +223,11 @@ void pv_hypercall(struct cpu_user_regs *regs)
             /* Deliberately corrupt parameter regs used by this hypercall. */
             switch ( hypercall_args_table[eax].compat )
             {
-            case 6: regs->ebp = 0xdeadf00d;
-            case 5: regs->edi = 0xdeadf00d;
-            case 4: regs->esi = 0xdeadf00d;
-            case 3: regs->edx = 0xdeadf00d;
-            case 2: regs->ecx = 0xdeadf00d;
+            case 6: regs->ebp = 0xdeadf00d; fallthrough;
+            case 5: regs->edi = 0xdeadf00d; fallthrough;
+            case 4: regs->esi = 0xdeadf00d; fallthrough;
+            case 3: regs->edx = 0xdeadf00d; fallthrough;
+            case 2: regs->ecx = 0xdeadf00d; fallthrough;
             case 1: regs->ebx = 0xdeadf00d;
             }
         }