From: Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>
To: Stephen Hemminger <stephen@networkplumber.org>, dev@dpdk.org
Subject: Re: [RFC] eal/x86: disable array bounds checks in rte_memcpy_generic with gcc-12
Date: Fri, 10 Jun 2022 01:08:20 +0100 [thread overview]
Message-ID: <27a9f959-70b8-9d6a-3019-f2e3ac2c91a9@yandex.ru> (raw)
In-Reply-To: <20220608224928.457440-1-stephen@networkplumber.org>
08/06/2022 23:49, Stephen Hemminger пишет:
> 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 <stephen@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
Acked-by: Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>
next prev parent reply other threads:[~2022-06-10 0:08 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-08 22:49 Stephen Hemminger
2022-06-09 7:26 ` Morten Brørup
2022-06-10 0:08 ` Konstantin Ananyev [this message]
2022-06-10 10:12 ` Ferruh Yigit
2022-06-10 10:39 ` Morten Brørup
2022-06-10 12:06 ` Ferruh Yigit
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