From f5a6c22f613d0566ba542f38f349be379e3844e8 Mon Sep 17 00:00:00 2001

From: Jerome Marchand <jmarchan@redhat.com>

Date: Wed, 26 Oct 2022 14:41:54 +0200

Subject: [PATCH 2/2] Fix clang 15 int to pointer conversion errors

Since version 15, clang issues error for implicit conversion of

integer to pointer. Several tools are broken. This patch add explicit

pointer cast where needed.

Fixes the following errors:

/virtual/main.c:37:18: error: incompatible integer to pointer conversion initializing 'struct request *' with an expression of type 'unsigned long' [-Wint-conversion]

 struct request *req = ctx->di;

                 ^     ~~~~~~~

/virtual/main.c:49:18: error: incompatible integer to pointer conversion initializing 'struct request *' with an expression of type 'unsigned long' [-Wint-conversion]

 struct request *req = ctx->di;

                 ^     ~~~~~~~

2 errors generated.

/virtual/main.c:73:19: error: incompatible integer to pointer conversion initializing 'struct pt_regs *' with an expression of type 'unsigned long' [-Wint-conversion]

 struct pt_regs * __ctx = ctx->di;

                  ^       ~~~~~~~

/virtual/main.c:100:240: error: incompatible integer to pointer conversion passing 'u64' (aka 'unsigned long long') to parameter of type 'const void *' [-Wint-conversion]

    data.ppid = ({ typeof(pid_t) _val; __builtin_memset(&_val, 0, sizeof(_val)); bpf_probe_read(&_val, sizeof(_val), (u64)&({ typeof(struct task_struct *) _val; __builtin_memset(&_val, 0, sizeof(_val)); bpf_probe_read(&_val, sizeof(_val), (u64)&task->real_parent); _val; })->tgid); _val; });

                                                                                                                                                                                                                                               ^~~~~~~~~~~~~~~~~~~~~~~

/virtual/main.c:100:118: error: incompatible integer to pointer conversion passing 'u64' (aka 'unsigned long long') to parameter of type 'const void *' [-Wint-conversion]

    data.ppid = ({ typeof(pid_t) _val; __builtin_memset(&_val, 0, sizeof(_val)); bpf_probe_read(&_val, sizeof(_val), (u64)&({ typeof(struct task_struct *) _val; __builtin_memset(&_val, 0, sizeof(_val)); bpf_probe_read(&_val, sizeof(_val), (u64)&task->real_parent); _val; })->tgid); _val; });

                                                                                                                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Jerome Marchand <jmarchan@redhat.com>

---

 src/cc/frontends/clang/b_frontend_action.cc | 18 +++++++++---------

 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/cc/frontends/clang/b_frontend_action.cc b/src/cc/frontends/clang/b_frontend_action.cc

index dbeba3e4..c0582464 100644

--- a/src/cc/frontends/clang/b_frontend_action.cc

+++ b/src/cc/frontends/clang/b_frontend_action.cc

@@ -517,9 +517,9 @@ bool ProbeVisitor::VisitUnaryOperator(UnaryOperator *E) {

   string pre, post;

   pre = "({ typeof(" + E->getType().getAsString() + ") _val; __builtin_memset(&_val, 0, sizeof(_val));";

   if (cannot_fall_back_safely)

-    pre += " bpf_probe_read_kernel(&_val, sizeof(_val), (u64)";

+    pre += " bpf_probe_read_kernel(&_val, sizeof(_val), (void *)";

   else

-    pre += " bpf_probe_read(&_val, sizeof(_val), (u64)";

+    pre += " bpf_probe_read(&_val, sizeof(_val), (void *)";

   post = "); _val; })";

   rewriter_.ReplaceText(expansionLoc(E->getOperatorLoc()), 1, pre);

   rewriter_.InsertTextAfterToken(expansionLoc(GET_ENDLOC(sub)), post);

@@ -581,9 +581,9 @@ bool ProbeVisitor::VisitMemberExpr(MemberExpr *E) {

   string pre, post;

   pre = "({ typeof(" + E->getType().getAsString() + ") _val; __builtin_memset(&_val, 0, sizeof(_val));";

   if (cannot_fall_back_safely)

-    pre += " bpf_probe_read_kernel(&_val, sizeof(_val), (u64)&";

+    pre += " bpf_probe_read_kernel(&_val, sizeof(_val), (void *)&";

   else

-    pre += " bpf_probe_read(&_val, sizeof(_val), (u64)&";

+    pre += " bpf_probe_read(&_val, sizeof(_val), (void *)&";

   post = rhs + "); _val; })";

   rewriter_.InsertText(expansionLoc(GET_BEGINLOC(E)), pre);

   rewriter_.ReplaceText(expansionRange(SourceRange(member, GET_ENDLOC(E))), post);

@@ -635,9 +635,9 @@ bool ProbeVisitor::VisitArraySubscriptExpr(ArraySubscriptExpr *E) {

   pre = "({ typeof(" + E->getType().getAsString() + ") _val; __builtin_memset(&_val, 0, sizeof(_val));";

   if (cannot_fall_back_safely)

-    pre += " bpf_probe_read_kernel(&_val, sizeof(_val), (u64)((";

+    pre += " bpf_probe_read_kernel(&_val, sizeof(_val), (void *)((";

   else

-    pre += " bpf_probe_read(&_val, sizeof(_val), (u64)((";

+    pre += " bpf_probe_read(&_val, sizeof(_val), (void *)((";

   if (isMemberDereference(base)) {

     pre += "&";

     // If the base of the array subscript is a member dereference, we'll rewrite

@@ -747,8 +747,8 @@ void BTypeVisitor::genParamDirectAssign(FunctionDecl *D, string& preamble,

       arg->addAttr(UnavailableAttr::CreateImplicit(C, "ptregs"));

       size_t d = idx - 1;

       const char *reg = calling_conv_regs[d];

-      preamble += " " + text + " = " + fn_args_[0]->getName().str() + "->" +

-                  string(reg) + ";";

+      preamble += " " + text + " = (" + arg->getType().getAsString() + ")" +

+                  fn_args_[0]->getName().str() + "->" + string(reg) + ";";

     }

   }

 }

@@ -762,7 +762,7 @@ void BTypeVisitor::genParamIndirectAssign(FunctionDecl *D, string& preamble,

     if (idx == 0) {

       new_ctx = "__" + arg->getName().str();

-      preamble += " struct pt_regs * " + new_ctx + " = " +

+      preamble += " struct pt_regs * " + new_ctx + " = (void *)" +

                   arg->getName().str() + "->" +

                   string(calling_conv_regs[0]) + ";";

     } else {

-- 

2.38.1