Gcc 12 adds more array bounds checking (good); but it is not smart
enough to realize that for small fixed sizes, the bigger move options
are not used.
An example is using rte_memcpy() on a RSS key of 40 bytes may trigger
rte_memcpy complaints from rte_mov128 reading past end of input.
In order to keep some of the checks add special case for calls
to rte_memcpy() with fixed size arguments to use the compiler
builtin instead. Don't want to give all the checking for
code that uses rte_memcpy() everywhere.
Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
---
lib/eal/x86/include/rte_memcpy.h | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/lib/eal/x86/include/rte_memcpy.h b/lib/eal/x86/include/rte_memcpy.h
index 18aa4e43a743..b90cdd8d7326 100644
--- a/lib/eal/x86/include/rte_memcpy.h
+++ b/lib/eal/x86/include/rte_memcpy.h
@@ -27,6 +27,10 @@ extern "C" {
#pragma GCC diagnostic ignored "-Wstringop-overflow"
#endif
+#if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION >= 120000)
+#pragma GCC diagnostic ignored "-Warray-bounds"
+#endif
+
/**
* Copy bytes from one location to another. The locations must not overlap.
*
@@ -842,19 +846,21 @@ rte_memcpy_aligned(void *dst, const void *src, size_t n)
return ret;
}
+#if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION >= 100000)
+#pragma GCC diagnostic pop
+#endif
+
static __rte_always_inline void *
rte_memcpy(void *dst, const void *src, size_t n)
{
- if (!(((uintptr_t)dst | (uintptr_t)src) & ALIGNMENT_MASK))
+ if (__builtin_constant_p(n))
+ return __builtin_memcpy(dst, src, n);
+ else if (!(((uintptr_t)dst | (uintptr_t)src) & ALIGNMENT_MASK))
return rte_memcpy_aligned(dst, src, n);
else
return rte_memcpy_generic(dst, src, n);
}
-#if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION >= 100000)
-#pragma GCC diagnostic pop
-#endif
-
#ifdef __cplusplus
}
#endif
--
2.35.1
