[dpdk-stable] patch 'eal/x86: ignore gcc 10 stringop-overflow warnings' has been queued to LTS release 18.11.9

[Kevin Traynor]

Hi,

FYI, your patch has been queued to LTS release 18.11.9

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 06/10/20. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable-queue

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable-queue/commit/2d982535371cdc6ee86dfdf8ed20a915d464843c

Thanks.

Kevin.

---
>From 2d982535371cdc6ee86dfdf8ed20a915d464843c Mon Sep 17 00:00:00 2001
From: Kevin Traynor <ktraynor at redhat.com>
Date: Fri, 17 Apr 2020 16:43:35 +0100
Subject: [PATCH] eal/x86: ignore gcc 10 stringop-overflow warnings
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

[ upstream commit b5b3ea803e4741ad6a46a38d8227c78226d9054d ]

stringop-overflow warns when it sees a possible overflow
in a string operation.

In the rte_memcpy functions different branches are taken
depending on the size. stringop-overflow is raised for the
branches in the function where it sees the static size of the
src could be overflowed.

However, in reality a correct size argument and in some cases
dynamic allocation would ensure that this does not happen.

For example, in the case below for key, the correct path will be
chosen in rte_memcpy_generic at runtime based on the size argument
but as some paths in the function could lead to a cast to 32 bytes
a warning is raised.

In function ‘_mm256_storeu_si256’,
inlined from ‘rte_memcpy_generic’
at ../lib/librte_eal/common/include/arch/x86/rte_memcpy.h:315:2,
inlined from ‘iavf_configure_rss_key’
at ../lib/librte_eal/common/include/arch/x86/rte_memcpy.h:869:10:

/usr/lib/gcc/x86_64-redhat-linux/10/include/avxintrin.h:928:8:
warning: writing 32 bytes into a region of size 1 [-Wstringop-overflow=]
  928 |   *__P = __A;
      |   ~~~~~^~~~~
In file included
from ../drivers/net/iavf/../../common/iavf/iavf_prototype.h:10,
from ../drivers/net/iavf/iavf.h:9,
from ../drivers/net/iavf/iavf_vchnl.c:22:

../drivers/net/iavf/iavf_vchnl.c:
In function ‘iavf_configure_rss_key’:

../drivers/net/iavf/../../common/iavf/virtchnl.h:508:5:
note: at offset 0 to object ‘key’ with size 1 declared here
  508 |  u8 key[1];         /* RSS hash key, packed bytes */
      |     ^~~

Ignore the stringop-overflow warnings for rte_memcpy.h functions.

Bugzilla ID: 394
Bugzilla ID: 421

Signed-off-by: Kevin Traynor <ktraynor at redhat.com>
Acked-by: Bruce Richardson <bruce.richardson at intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
---
 lib/librte_eal/common/include/arch/x86/rte_memcpy.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/lib/librte_eal/common/include/arch/x86/rte_memcpy.h b/lib/librte_eal/common/include/arch/x86/rte_memcpy.h
index ba44c4a328..9c67232df9 100644
--- a/lib/librte_eal/common/include/arch/x86/rte_memcpy.h
+++ b/lib/librte_eal/common/include/arch/x86/rte_memcpy.h
@@ -23,4 +23,9 @@ extern "C" {
 #endif
 
+#if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION >= 100000)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wstringop-overflow"
+#endif
+
 /**
  * Copy bytes from one location to another. The locations must not overlap.
@@ -870,4 +875,8 @@ rte_memcpy(void *dst, const void *src, size_t n)
 }
 
+#if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION >= 100000)
+#pragma GCC diagnostic pop
+#endif
+
 #ifdef __cplusplus
 }
-- 
2.21.3

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-06-05 19:20:51.233448247 +0100
+++ 0005-eal-x86-ignore-gcc-10-stringop-overflow-warnings.patch	2020-06-05 19:20:50.705043199 +0100
@@ -1 +1 @@
-From b5b3ea803e4741ad6a46a38d8227c78226d9054d Mon Sep 17 00:00:00 2001
+From 2d982535371cdc6ee86dfdf8ed20a915d464843c Mon Sep 17 00:00:00 2001
@@ -8,0 +9,2 @@
+[ upstream commit b5b3ea803e4741ad6a46a38d8227c78226d9054d ]
+
@@ -52 +53,0 @@
-Cc: stable at dpdk.org
@@ -58 +59 @@
- lib/librte_eal/x86/include/rte_memcpy.h | 9 +++++++++
+ lib/librte_eal/common/include/arch/x86/rte_memcpy.h | 9 +++++++++
@@ -61 +62 @@
-diff --git a/lib/librte_eal/x86/include/rte_memcpy.h b/lib/librte_eal/x86/include/rte_memcpy.h
+diff --git a/lib/librte_eal/common/include/arch/x86/rte_memcpy.h b/lib/librte_eal/common/include/arch/x86/rte_memcpy.h
@@ -63,2 +64,2 @@
---- a/lib/librte_eal/x86/include/rte_memcpy.h
-+++ b/lib/librte_eal/x86/include/rte_memcpy.h
+--- a/lib/librte_eal/common/include/arch/x86/rte_memcpy.h
++++ b/lib/librte_eal/common/include/arch/x86/rte_memcpy.h