executor: introduce force_inline

Turned out executor_fn_guest_addr() was not inlined when building
the reproducers with -O0, so the guest code crashed.

2 files changed, 6 insertions, 3 deletions

diff --git a/executor/common_kvm.h b/executor/common_kvm.h
index b413d9370..80253fb19 100644
--- a/executor/common_kvm.h
+++ b/executor/common_kvm.h
@@ -15,7 +15,7 @@
 extern char* __start_guest;
 
 // executor_fn_guest_addr() is compiled into both the host and the guest code.
-static inline uintptr_t executor_fn_guest_addr(void* fn)
+static always_inline uintptr_t executor_fn_guest_addr(void* fn)
 {
 	// Prevent the compiler from creating a .rodata constant for
 	// &__start_guest + SYZOS_ADDR_EXECUTOR_CODE.
@@ -28,7 +28,7 @@ static inline uintptr_t executor_fn_guest_addr(void* fn)
 // In Clang-based C++ builds, use template magic to ensure that only guest functions can be passed
 // to executor_fn_guest_addr().
 template <typename R, typename... A>
-uintptr_t static inline executor_fn_guest_addr(__addrspace_guest R (*fn)(A...))
+uintptr_t static always_inline executor_fn_guest_addr(__addrspace_guest R (*fn)(A...))
 {
 	return executor_fn_guest_addr((void*)fn);
 }
@@ -64,4 +64,4 @@ static long syz_kvm_assert_syzos_kvm_exit(volatile long a0, volatile long a1)
 }
 #endif
 
-#endif // EXECUTOR_COMMON_KVM_H
\ No newline at end of file
+#endif // EXECUTOR_COMMON_KVM_H
diff --git a/executor/common_kvm_syzos.h b/executor/common_kvm_syzos.h
index 923284efe..096ff2556 100644
--- a/executor/common_kvm_syzos.h
+++ b/executor/common_kvm_syzos.h
@@ -11,6 +11,9 @@
 // (e.g. generate switch tables).
 #define noinline __attribute__((noinline))
 
+// Force inlining as much as possible.
+#define always_inline __attribute__((always_inline)) inline
+
 // __no_stack_protector disables -fstack-protector which may introduce unwanted global accesses.
 // TODO(glider): once syz-env-old migrates to GCC>11 we can just use
 // __attribute__((no_stack_protector)).