From b7b7ac19fd9e2afbf5aea4db5e3f318576e6809f Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Tue, 26 Dec 2017 09:39:22 +0100
Subject: executor: check format strings

I see a crash which says:

	#0: too much cover 0 (errno 0)

while the code is:

	uint64_t n = ...;
	if (n >= kCoverSize)
		fail("#%d: too much cover %u", th->id, n);

It seems that the high part of n is set, but we don't see it.

Add printf format attribute to fail and friends and fix all similar cases.
Caught a bunch of similar cases and a missing argument in:

exitf("opendir(%s) failed due to NOFILE, exiting");
---
 executor/common.h | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

(limited to 'executor/common.h')

diff --git a/executor/common.h b/executor/common.h
index 78b752045..50348023f 100644
--- a/executor/common.h
+++ b/executor/common.h
@@ -28,18 +28,22 @@
 // because some standard libraries contain "using ::exit;", but has different signature.
 #define exit vsnprintf
 #define _exit vsnprintf
-#endif
 
-#if defined(SYZ_EXECUTOR)
+// uint64_t is impossible to printf without using the clumsy and verbose "%" PRId64.
+// So we do the define and use "%lld" to printf uint64_t's.
+#define uint64_t unsigned long long
+
 #if defined(__GNUC__)
 #define SYSCALLAPI
 #define NORETURN __attribute__((noreturn))
 #define ALIGNED(N) __attribute__((aligned(N)))
+#define PRINTF __attribute__((format(printf, 1, 2)))
 #else
 // Assuming windows/cl.
 #define SYSCALLAPI WINAPI
 #define NORETURN __declspec(noreturn)
 #define ALIGNED(N) __declspec(align(N))
+#define PRINTF
 #endif
 
 typedef long(SYSCALLAPI* syscall_t)(long, long, long, long, long, long, long, long, long);
@@ -53,7 +57,7 @@ struct call_t {
 // Defined in generated syscalls_OS.h files.
 extern call_t syscalls[];
 extern unsigned syscall_count;
-#endif
+#endif // #if defined(SYZ_EXECUTOR)
 
 #if defined(SYZ_EXECUTOR) || (defined(SYZ_REPEAT) && defined(SYZ_WAIT_REPEAT)) ||               \
     defined(SYZ_USE_TMP_DIR) || defined(SYZ_TUN_ENABLE) || defined(SYZ_SANDBOX_NAMESPACE) ||    \
@@ -71,7 +75,7 @@ const int kErrorStatus = 68;
     defined(SYZ_USE_TMP_DIR) || defined(SYZ_TUN_ENABLE) || defined(SYZ_SANDBOX_NAMESPACE) || \
     defined(SYZ_SANDBOX_NONE) || defined(SYZ_SANDBOX_SETUID) || defined(__NR_syz_kvm_setup_cpu)
 // logical error (e.g. invalid input program), use as an assert() alernative
-NORETURN static void fail(const char* msg, ...)
+NORETURN PRINTF static void fail(const char* msg, ...)
 {
 	int e = errno;
 	va_list args;
@@ -87,7 +91,7 @@ NORETURN static void fail(const char* msg, ...)
 
 #if defined(SYZ_EXECUTOR)
 // kernel error (e.g. wrong syscall return value)
-NORETURN static void error(const char* msg, ...)
+NORETURN PRINTF static void error(const char* msg, ...)
 {
 	va_list args;
 	va_start(args, msg);
@@ -100,7 +104,7 @@ NORETURN static void error(const char* msg, ...)
 
 #if defined(SYZ_EXECUTOR) || (defined(SYZ_REPEAT) && defined(SYZ_WAIT_REPEAT) && defined(SYZ_USE_TMP_DIR)) || defined(SYZ_FAULT_INJECTION)
 // just exit (e.g. due to temporal ENOMEM error)
-NORETURN static void exitf(const char* msg, ...)
+NORETURN PRINTF static void exitf(const char* msg, ...)
 {
 	int e = errno;
 	va_list args;
@@ -115,7 +119,7 @@ NORETURN static void exitf(const char* msg, ...)
 #if defined(SYZ_EXECUTOR) || defined(SYZ_DEBUG)
 static int flag_debug;
 
-static void debug(const char* msg, ...)
+PRINTF static void debug(const char* msg, ...)
 {
 	if (!flag_debug)
 		return;
-- 
cgit mrf-deployment