[xen staging] MISRA C Rule 17.1 states: "The features of `<stdarg.h>' shall not be used"

[patchbot@xxxxxxx]

commit 402c2d3e66a6bc9481dcabfc8697750dc4beabed
Author:     Simone Ballarin <simone.ballarin@xxxxxxxxxxx>
AuthorDate: Thu Mar 28 11:29:35 2024 +0100
Commit:     Stefano Stabellini <stefano.stabellini@xxxxxxx>
CommitDate: Fri Apr 5 11:15:47 2024 -0700

    MISRA C Rule 17.1 states: "The features of `<stdarg.h>' shall not be used"
    
    The Xen community wants to avoid using variadic functions except for
    specific circumstances where it feels appropriate by strict code review.
    
    Functions hypercall_create_continuation and hypercall_xlat_continuation
    are internal helper functions made to break long running hypercalls into
    multiple calls. They take a variable number of arguments depending on the
    original hypercall they are trying to continue.
    
    Add SAF deviations for the aforementioned functions.
    
    Signed-off-by: Simone Ballarin <simone.ballarin@xxxxxxxxxxx>
    Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 docs/misra/safe.json     | 8 ++++++++
 xen/arch/arm/domain.c    | 1 +
 xen/arch/x86/hypercall.c | 2 ++
 3 files changed, 11 insertions(+)

diff --git a/docs/misra/safe.json b/docs/misra/safe.json
index d361d0e65c..fe2bc18509 100644
--- a/docs/misra/safe.json
+++ b/docs/misra/safe.json
@@ -36,6 +36,14 @@
         },
         {
             "id": "SAF-4-safe",
+            "analyser": {
+                "eclair": "MC3R1.R17.1"
+            },
+            "name": "Rule 17.1: internal helper functions made to break long 
running hypercalls into multiple calls.",
+            "text": "They need to take a variable number of arguments 
depending on the original hypercall they are trying to continue."
+        },
+        {
+            "id": "SAF-5-safe",
             "analyser": {},
             "name": "Sentinel",
             "text": "Next ID to be used"
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index f38cb5e04c..34cbfe699a 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -382,6 +382,7 @@ unsigned long hypercall_create_continuation(
     const char *p = format;
     unsigned long arg, rc;
     unsigned int i;
+    /* SAF-4-safe allowed variadic function */
     va_list args;
 
     current->hcall_preempted = true;
diff --git a/xen/arch/x86/hypercall.c b/xen/arch/x86/hypercall.c
index 01cd73040d..133e9f221c 100644
--- a/xen/arch/x86/hypercall.c
+++ b/xen/arch/x86/hypercall.c
@@ -31,6 +31,7 @@ unsigned long hypercall_create_continuation(
     const char *p = format;
     unsigned long arg;
     unsigned int i;
+    /* SAF-4-safe allowed variadic function */
     va_list args;
 
     curr->hcall_preempted = true;
@@ -115,6 +116,7 @@ int hypercall_xlat_continuation(unsigned int *id, unsigned 
int nr,
     struct cpu_user_regs *regs;
     unsigned int i, cval = 0;
     unsigned long nval = 0;
+    /* SAF-4-safe allowed variadic function */
     va_list args;
 
     ASSERT(nr <= ARRAY_SIZE(mcs->call.args));
--
generated by git-patchbot for /home/xen/git/xen.git#staging