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tests/unit/test_xasprintf.c: Fix use of volatile pointer

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volatile needs to be casted away behind a [[gnu::noipa]] function, to
make that invisible to the compiler.  Otherwise, the compiler can see
that it is being discarded, and is free to abuse Undefined Behavior.

Closes: <https://github.com/shadow-maint/shadow/issues/1028>
Reported-by: Chris Hofstaedtler <zeha@debian.org>
Tested-by: Chris Hofstaedtler <zeha@debian.org>
Reviewed-by: Chris Hofstaedtler <zeha@debian.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
This commit is contained in:
Alejandro Colomar
2024-06-28 08:57:01 -05:00
committed by Serge Hallyn
parent 3307a8f4f0
commit 6e57238bf9
1 changed files with 18 additions and 1 deletions
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tests/unit/test_xasprintf.c
+18 -1
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@@ -5,6 +5,7 @@
#include <setjmp.h> #include <setjmp.h>
#include <stdarg.h>
#include <stddef.h> #include <stddef.h>
#include <stdlib.h> #include <stdlib.h>
#include <string.h> #include <string.h>
@@ -32,6 +33,10 @@ int __real_vasprintf(char **restrict p, const char *restrict fmt, va_list ap);
int __wrap_vasprintf(char **restrict p, const char *restrict fmt, va_list ap); int __wrap_vasprintf(char **restrict p, const char *restrict fmt, va_list ap);
void __wrap_exit(int status); void __wrap_exit(int status);
[[gnu::noipa]]
static int xasprintf_volatile(char *volatile *restrict s,
const char *restrict fmt, ...);
static void test_xasprintf_exit(void **state); static void test_xasprintf_exit(void **state);
static void test_xasprintf_ok(void **state); static void test_xasprintf_ok(void **state);
@@ -62,6 +67,18 @@ __wrap_exit(int status)
} }
static int
xasprintf_volatile(char *volatile *restrict s, const char *restrict fmt, ...)
{
int len;
va_list ap;
va_start(ap, fmt);
len = xvasprintf((char **) s, fmt, ap);
va_end(ap);
}
static void static void
test_xasprintf_exit(void **state) test_xasprintf_exit(void **state)
{ {
@@ -75,7 +92,7 @@ test_xasprintf_exit(void **state)
switch (setjmp(jmpb)) { switch (setjmp(jmpb)) {
case 0: case 0:
len = XASPRINTF_CALLED; len = XASPRINTF_CALLED;
len = xasprintf(&p, "foo%s", "bar"); len = xasprintf_volatile(&p, "foo%s", "bar");
assert_unreachable(); assert_unreachable();
break; break;
case EXIT_CALLED: case EXIT_CALLED: