diff options
Diffstat (limited to 'tests/checkasm/checkasm.h')
| -rw-r--r-- | tests/checkasm/checkasm.h | 65 |
1 files changed, 42 insertions, 23 deletions
diff --git a/tests/checkasm/checkasm.h b/tests/checkasm/checkasm.h index fb5f8ed..29c1dbe 100644 --- a/tests/checkasm/checkasm.h +++ b/tests/checkasm/checkasm.h @@ -185,17 +185,6 @@ static inline uint64_t readtime(void) { void checkasm_checked_call(void *func, ...); #if ARCH_X86_64 -/* Evil hack: detect incorrect assumptions that 32-bit ints are zero-extended - * to 64-bit. This is done by clobbering the stack with junk around the stack - * pointer and calling the assembly function through checked_call() with added - * dummy arguments which forces all real arguments to be passed on the stack - * and not in registers. For 32-bit arguments the upper half of the 64-bit - * register locations on the stack will now contain junk which will cause - * misbehaving functions to either produce incorrect output or segfault. Note - * that even though this works extremely well in practice, it's technically - * not guaranteed and false negatives is theoretically possible, but there - * can never be any false positives. */ -void checkasm_stack_clobber(uint64_t clobber, ...); /* YMM and ZMM registers on x86 are turned off to save power when they haven't * been used for some period of time. When they are used there will be a * "warmup" period during which performance will be reduced and inconsistent @@ -203,24 +192,54 @@ void checkasm_stack_clobber(uint64_t clobber, ...); * work around this by periodically issuing "dummy" instructions that uses * those registers to keep them powered on. */ void checkasm_simd_warmup(void); -#define declare_new(ret, ...)\ - ret (*checked_call)(void *, int, int, int, int, int, __VA_ARGS__,\ - int, int, int, int, int, int, int, int,\ - int, int, int, int, int, int, int) =\ - (void *)checkasm_checked_call; -#define CLOB (UINT64_C(0xdeadbeefdeadbeef)) + +/* The upper 32 bits of 32-bit data types are undefined when passed as function + * parameters. In practice those bits usually end up being zero which may hide + * certain bugs, such as using a register containing undefined bits as a pointer + * offset, so we want to intentionally clobber those bits with junk to expose + * any issues. The following set of macros automatically calculates a bitmask + * specifying which parameters should have their upper halves clobbered. */ #ifdef _WIN32 -#define STACKARGS 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 0, 0, 0 +/* Integer and floating-point parameters share "register slots". */ +#define IGNORED_FP_ARGS 0 #else -#define STACKARGS 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 0, 0, 0, 0, 0 +/* Up to 8 floating-point parameters are passed in XMM registers, which are + * handled orthogonally from integer parameters passed in GPR registers. */ +#define IGNORED_FP_ARGS 8 #endif +#ifdef HAVE_C11_GENERIC +#define clobber_type(arg) _Generic((void (*)(void*, arg))NULL,\ + void (*)(void*, int32_t ): clobber_mask |= 1 << mpos++,\ + void (*)(void*, uint32_t): clobber_mask |= 1 << mpos++,\ + void (*)(void*, float ): mpos += (fp_args++ >= IGNORED_FP_ARGS),\ + void (*)(void*, double ): mpos += (fp_args++ >= IGNORED_FP_ARGS),\ + default: mpos++) +#define init_clobber_mask(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, ...)\ + unsigned clobber_mask = 0;\ + {\ + int mpos = 0, fp_args = 0;\ + clobber_type(a); clobber_type(b); clobber_type(c); clobber_type(d);\ + clobber_type(e); clobber_type(f); clobber_type(g); clobber_type(h);\ + clobber_type(i); clobber_type(j); clobber_type(k); clobber_type(l);\ + clobber_type(m); clobber_type(n); clobber_type(o); clobber_type(p);\ + } +#else +/* Skip parameter clobbering on compilers without support for _Generic() */ +#define init_clobber_mask(...) unsigned clobber_mask = 0 +#endif +#define declare_new(ret, ...)\ + ret (*checked_call)(__VA_ARGS__, int, int, int, int, int, int, int,\ + int, int, int, int, int, int, int, int, int,\ + void*, unsigned) =\ + (void*)checkasm_checked_call;\ + init_clobber_mask(__VA_ARGS__, void*, void*, void*, void*,\ + void*, void*, void*, void*, void*, void*,\ + void*, void*, void*, void*, void*); #define call_new(...)\ (checkasm_set_signal_handler_state(1),\ checkasm_simd_warmup(),\ - checkasm_stack_clobber(CLOB, CLOB, CLOB, CLOB, CLOB, CLOB, CLOB,\ - CLOB, CLOB, CLOB, CLOB, CLOB, CLOB, CLOB,\ - CLOB, CLOB, CLOB, CLOB, CLOB, CLOB, CLOB),\ - checked_call(func_new, 0, 0, 0, 0, 0, __VA_ARGS__, STACKARGS));\ + checked_call(__VA_ARGS__, 16, 15, 14, 13, 12, 11, 10, 9, 8,\ + 7, 6, 5, 4, 3, 2, 1, func_new, clobber_mask));\ checkasm_set_signal_handler_state(0) #elif ARCH_X86_32 #define declare_new(ret, ...)\ |