From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: Michael Qiu <qdy220091330@gmail.com>, "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v2] test-pmd: Fix pointer aliasing error
Date: Thu, 4 Dec 2014 12:54:47 +0000 [thread overview]
Message-ID: <2601191342CEEE43887BDE71AB977258213BC8B1@IRSMSX105.ger.corp.intel.com> (raw)
In-Reply-To: <1417663711-19576-1-git-send-email-michael.qiu@intel.com>
> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Michael Qiu
> Sent: Thursday, December 04, 2014 3:29 AM
> To: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH v2] test-pmd: Fix pointer aliasing error
>
>
> app/test-pmd/csumonly.c: In function ‘get_psd_sum’:
> build/include/rte_ip.h:161: error: dereferencing pointer ‘u16’
> does break strict-aliasing rules
> build/include/rte_ip.h:157: note: initialized from here
> ...
>
> The root cause is that, compile enable strict aliasing by default,
> while in function rte_raw_cksum() try to convert 'const char *'
> to 'const uint16_t *'.
>
> This patch is one workaround fix.
>
> Signed-off-by: Michael Qiu <michael.qiu@intel.com>
> ---
> lib/librte_net/rte_ip.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h
> index 61e4457..f1c7087 100644
> --- a/lib/librte_net/rte_ip.h
> +++ b/lib/librte_net/rte_ip.h
> @@ -154,7 +154,8 @@ struct ipv4_hdr {
> static inline uint16_t
> rte_raw_cksum(const char *buf, size_t len)
> {
> - const uint16_t *u16 = (const uint16_t *)buf;
> + unsigned long ptr = (unsigned long)buf;
I think better use uintptr_t here.
It is specially designed to be long enough to hold pointer value.
> + const uint16_t *u16 = (const uint16_t *)ptr;
> uint32_t sum = 0;
>
> while (len >= (sizeof(*u16) * 4)) {
> --
> 1.9.3
next prev parent reply other threads:[~2014-12-04 12:54 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1417606044-3432-1-git-send-email-michael.qiu@intel.com>
[not found] ` <1417606099-3489-1-git-send-email-michael.qiu@intel.com>
2014-12-03 11:42 ` [dpdk-dev] [PATCH] " Bruce Richardson
2014-12-03 13:59 ` Qiu, Michael
2014-12-03 14:51 ` Bruce Richardson
2014-12-03 15:19 ` Qiu, Michael
2014-12-03 15:36 ` Bruce Richardson
2014-12-04 2:38 ` Qiu, Michael
2014-12-04 3:28 ` [dpdk-dev] [PATCH v2] " Michael Qiu
2014-12-04 4:16 ` [dpdk-dev] [PATCH v3] " Michael Qiu
2014-12-05 5:34 ` Qiu, Michael
2014-12-05 9:24 ` Thomas Monjalon
2014-12-08 1:28 ` Qiu, Michael
2014-12-08 1:30 ` Qiu, Michael
2014-12-10 3:44 ` Qiu, Michael
2014-12-11 0:54 ` Thomas Monjalon
2014-12-11 17:51 ` r k
2014-12-12 6:49 ` Qiu, Michael
2014-12-04 12:54 ` Ananyev, Konstantin [this message]
2014-12-03 15:24 ` [dpdk-dev] [PATCH] " Olivier MATZ
2014-12-03 16:03 ` Dayu Qiu
2014-12-03 15:57 ` Dayu Qiu
2014-12-03 16:26 ` [dpdk-dev] [PATCH] test-pmd: Fix "__BYTE_ORDER__" not defined error Qiu, Michael
2014-12-03 19:59 ` Thomas Monjalon
2014-12-03 20:47 ` [dpdk-dev] [PATCH 0/2] fix endianness in EAL Thomas Monjalon
2014-12-03 20:47 ` [dpdk-dev] [PATCH 1/2] eal: detect endianness Thomas Monjalon
2014-12-04 2:28 ` Qiu, Michael
2014-12-04 9:00 ` Thomas Monjalon
2014-12-04 10:28 ` Qiu, Michael
2014-12-04 12:19 ` Thomas Monjalon
2014-12-04 12:50 ` Qiu, Michael
2014-12-03 20:47 ` [dpdk-dev] [PATCH 2/2] app/testpmd: fix endianness detection Thomas Monjalon
2014-12-04 9:28 ` [dpdk-dev] [PATCH 0/2] fix endianness in EAL Chao Zhu
2014-12-05 16:01 ` Thomas Monjalon
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