executor: prevent non-null expected warnings

The added test triggers warnings like these:

<stdin>: In function ‘syz_mount_image.constprop’:
<stdin>:298:3: error: argument 1 null where non-null expected [-Werror=nonnull]
In file included from <stdin>:26:0:
/usr/include/x86_64-linux-gnu/sys/stat.h:320:12: note: in a call to function ‘mkdir’ declared here
 extern int mkdir (const char *__path, __mode_t __mode)
            ^~~~~
cc1: all warnings being treated as errors

<stdin>: In function ‘syz_open_procfs.constprop’:
<stdin>:530:41: error: ‘%s’ directive argument is null [-Werror=format-truncation=]
<stdin>:85:110: note: in definition of macro ‘NONFAILING’
<stdin>:532:41: error: ‘%s’ directive argument is null [-Werror=format-truncation=]
<stdin>:85:110: note: in definition of macro ‘NONFAILING’
<stdin>:534:41: error: ‘%s’ directive argument is null [-Werror=format-truncation=]
<stdin>:85:110: note: in definition of macro ‘NONFAILING’

Use volatile for all arguments of syz_ functions to prevent
compiler from treating the arguments as constants in reproducers.

Popped up during bisection that used a repro that previously worked.
Update #501

1 files changed, 1 insertions, 1 deletions

diff --git a/executor/common.h b/executor/common.h
index 1d4d1883c..9531d4a3e 100644
--- a/executor/common.h
+++ b/executor/common.h
@@ -381,7 +381,7 @@ static uint16 csum_inet_digest(struct csum_inet* csum)
 
 #if SYZ_EXECUTOR || __NR_syz_execute_func
 // syz_execute_func(text ptr[in, text[taget]])
-static long syz_execute_func(long text)
+static long syz_execute_func(volatile long text)
 {
 	((void (*)(void))(text))();
 	return 0;