From c17a12ac030c5d9c812e611f8132570af0e795af Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Sat, 13 Aug 2022 17:50:07 -0700 Subject: [PATCH 1/2] Fix bpf_pseudo_fd() type conversion error With llvm15 and llvm16, the following command line sudo ./trace.py 'smp_call_function_single "%K", arg1' will cause error: /virtual/main.c:60:36: error: incompatible integer to pointer conversion passing 'u64' (aka 'unsigned long long') to parameter of type 'void *' [-Wint-conversion] bpf_perf_event_output(ctx, bpf_pseudo_fd(1, -1), CUR_CPU_IDENTIFIER, &__data, sizeof(__data)); ^~~~~~~~~~~~~~~~~~~~ 1 error generated. Failed to compile BPF module In helpers.h, we have u64 bpf_pseudo_fd(u64, u64) asm("llvm.bpf.pseudo"); Apparently, <= llvm14 can tolerate u64 -> 'void *' conversion, but llvm15 by default will cause an error. Let us explicitly convert bpf_pseudo_fd to 'void *' to avoid such errors. Signed-off-by: Yonghong Song --- src/cc/frontends/clang/b_frontend_action.cc | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/src/cc/frontends/clang/b_frontend_action.cc b/src/cc/frontends/clang/b_frontend_action.cc index a4e05b16..dbeba3e4 100644 --- a/src/cc/frontends/clang/b_frontend_action.cc +++ b/src/cc/frontends/clang/b_frontend_action.cc @@ -957,7 +957,7 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) { string arg0 = rewriter_.getRewrittenText(expansionRange(Call->getArg(0)->getSourceRange())); string args_other = rewriter_.getRewrittenText(expansionRange(SourceRange(GET_BEGINLOC(Call->getArg(1)), GET_ENDLOC(Call->getArg(2))))); - txt = "bpf_perf_event_output(" + arg0 + ", bpf_pseudo_fd(1, " + fd + ")"; + txt = "bpf_perf_event_output(" + arg0 + ", (void *)bpf_pseudo_fd(1, " + fd + ")"; txt += ", CUR_CPU_IDENTIFIER, " + args_other + ")"; // e.g. @@ -986,7 +986,7 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) { string meta_len = rewriter_.getRewrittenText(expansionRange(Call->getArg(3)->getSourceRange())); txt = "bpf_perf_event_output(" + skb + ", " + - "bpf_pseudo_fd(1, " + fd + "), " + + "(void *)bpf_pseudo_fd(1, " + fd + "), " + "((__u64)" + skb_len + " << 32) | BPF_F_CURRENT_CPU, " + meta + ", " + meta_len + ");"; @@ -1006,12 +1006,12 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) { string keyp = rewriter_.getRewrittenText(expansionRange(Call->getArg(1)->getSourceRange())); string flag = rewriter_.getRewrittenText(expansionRange(Call->getArg(2)->getSourceRange())); txt = "bpf_" + string(memb_name) + "(" + ctx + ", " + - "bpf_pseudo_fd(1, " + fd + "), " + keyp + ", " + flag + ");"; + "(void *)bpf_pseudo_fd(1, " + fd + "), " + keyp + ", " + flag + ");"; } else if (memb_name == "ringbuf_output") { string name = string(Ref->getDecl()->getName()); string args = rewriter_.getRewrittenText(expansionRange(SourceRange(GET_BEGINLOC(Call->getArg(0)), GET_ENDLOC(Call->getArg(2))))); - txt = "bpf_ringbuf_output(bpf_pseudo_fd(1, " + fd + ")"; + txt = "bpf_ringbuf_output((void *)bpf_pseudo_fd(1, " + fd + ")"; txt += ", " + args + ")"; // e.g. @@ -1033,7 +1033,7 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) { } else if (memb_name == "ringbuf_reserve") { string name = string(Ref->getDecl()->getName()); string arg0 = rewriter_.getRewrittenText(expansionRange(Call->getArg(0)->getSourceRange())); - txt = "bpf_ringbuf_reserve(bpf_pseudo_fd(1, " + fd + ")"; + txt = "bpf_ringbuf_reserve((void *)bpf_pseudo_fd(1, " + fd + ")"; txt += ", " + arg0 + ", 0)"; // Flags in reserve are meaningless } else if (memb_name == "ringbuf_discard") { string name = string(Ref->getDecl()->getName()); -- 2.38.1