Work around a gcc warning

It seems that annotating sprintf with `write` makes gcc unhappy, as its
analyser is unable to understand that we're checking if `__b != -1` before
calling `__orig_snprintf`, so let's comment this annotation for now.

4 files changed, 38 insertions, 7 deletions

diff --git a/include/stdio.h b/include/stdio.h
index c1070a8..3e31f29 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -286,7 +286,7 @@ _FORTIFY_FN(snprintf) int snprintf(char *__s, size_t __n,
 }
 
 __fh_format(printf, 2, 3)
-__fh_access(write_only, 1)
+//__fh_access(write_only, 1)
 __fh_access(read_only, 2)
 _FORTIFY_FN(sprintf) int sprintf(char *__s, const char *__f, ...)
 {
@@ -296,13 +296,13 @@ _FORTIFY_FN(sprintf) int sprintf(char *__s, const char *__f, ...)
         __fh_size_t __b = __fh_bos(__s, 0);
         int __r;
 
-        if (__b != (__fh_size_t)-1) {
-                __r = __orig_snprintf(__s, __b, __f, __builtin_va_arg_pack());
-                if (__r != -1 && (__fh_size_t)__r >= __b)
-                        __builtin_trap();
-        } else {
-                __r = __orig_sprintf(__s, __f, __builtin_va_arg_pack());
+        if (__b == (__fh_size_t)-1) {
+                return __orig_sprintf(__s, __f, __builtin_va_arg_pack());
         }
+
+        __r = __orig_snprintf(__s, __b, __f, __builtin_va_arg_pack());
+        if (__r != -1 && (__fh_size_t)__r >= __b)
+                __builtin_trap();
         return __r;
 #endif
 }
diff --git a/tests/Makefile b/tests/Makefile
index d29a87d..333f088 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -96,6 +96,8 @@ RUNTIME_TARGETS= \
         test_send_static             \
         test_sendto_dynamic          \
         test_sendto_static           \
+        test_sprintf                 \
+        test_sprintf_62              \
         test_stpcpy_dynamic_write    \
         test_stpcpy_overwrite_over   \
         test_stpcpy_overwrite_under  \
diff --git a/tests/test_sprintf.c b/tests/test_sprintf.c
new file mode 100644
index 0000000..edde838
--- /dev/null
+++ b/tests/test_sprintf.c
@@ -0,0 +1,8 @@
+#include "common.h"
+
+#include <stdio.h>
+
+int main(int argc, char** argv) {
+  char buffer[12] = {0};
+  sprintf(buffer, "%s", "1234567");
+}
diff --git a/tests/test_sprintf_62.c b/tests/test_sprintf_62.c
new file mode 100644
index 0000000..3a84a1f
--- /dev/null
+++ b/tests/test_sprintf_62.c
@@ -0,0 +1,21 @@
+#include "common.h"
+
+#include <stdio.h>
+
+static char *offstr(char *str)
+{
+        int len = 0;
+
+        len = sprintf(str, "%s+0x%lx", "foo", (long unsigned int)0);
+        sprintf(str+len, " (%s+0x%lx)","bar", (long unsigned int)0);
+        if (len < 0)
+                return NULL;
+        return str;
+}
+
+int main() {
+        char buf[100];
+        char *c = offstr(buf);
+        printf("%s\n", c);
+        return 0;
+}