From 15d2cdc331828a80b528650b25415c9edca4f421 Mon Sep 17 00:00:00 2001
From: Andrei Vagin <avagin@google.com>
Date: Thu, 5 Sep 2024 18:15:57 -0700
Subject: [PATCH] tests: check fpu registers before doing any function call

Function calls can "corrupt" fpu registers.

PiperOrigin-RevId: 671577096
---
 test/syscalls/linux/fpsig_fork.cc   | 4 ++--
 test/syscalls/linux/fpsig_nested.cc | 7 ++++---
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/test/syscalls/linux/fpsig_fork.cc b/test/syscalls/linux/fpsig_fork.cc
index ae03fe3ba..a6d86598d 100644
--- a/test/syscalls/linux/fpsig_fork.cc
+++ b/test/syscalls/linux/fpsig_fork.cc
@@ -110,11 +110,11 @@ TEST(FPSigTest, Fork) {
   asm volatile("svc #0\n" : "=r"(x0) : "r"(x0), "r"(x1), "r"(x2), "r"(x8) :);
   ret = x0;
 #endif
-  EXPECT_EQ(ret, 0);
-
   uint64_t got;
   GET_FP0(got);
 
+  EXPECT_EQ(ret, 0);
+
   if (getpid() == parent) {  // Parent.
     int status;
     ASSERT_THAT(waitpid(child, &status, 0), SyscallSucceedsWithValue(child));
diff --git a/test/syscalls/linux/fpsig_nested.cc b/test/syscalls/linux/fpsig_nested.cc
index 0f2368448..f5840d578 100644
--- a/test/syscalls/linux/fpsig_nested.cc
+++ b/test/syscalls/linux/fpsig_nested.cc
@@ -82,11 +82,12 @@ void sigusr1(int s, siginfo_t* siginfo, void* _uc) {
   asm volatile("svc #0\n" : "=r"(x0) : "r"(x0), "r"(x1), "r"(x2), "r"(x8) :);
   ret = x0;
 #endif
-  EXPECT_EQ(ret, 0);
 
   // Record value of %xmm0 again to verify that the nested signal handler
   // does not clobber it.
   GET_FP0(exitxmm[0]);
+
+  EXPECT_EQ(ret, 0);
 }
 
 TEST(FPSigTest, NestedSignals) {
@@ -132,11 +133,11 @@ TEST(FPSigTest, NestedSignals) {
   asm volatile("svc #0\n" : "=r"(x0) : "r"(x0), "r"(x1), "r"(x2), "r"(x8) :);
   ret = x0;
 #endif
-  EXPECT_EQ(ret, 0);
-
   uint64_t got;
   GET_FP0(got);
 
+  EXPECT_EQ(ret, 0);
+
   //
   // The checks below verifies the following:
   // - signal handlers must called with a clean fpu state.