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From: Thomas Monjalon <thomas@monjalon.net>
To: dev@dpdk.org
Cc: stable@dpdk.org, Matan Azrad <matan@mellanox.com>,
	Shahaf Shuler <shahafs@mellanox.com>,
	Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Subject: [dpdk-dev] [PATCH v2 2/3] common/mlx5: fix build with -fno-common
Date: Wed,  8 Apr 2020 01:06:46 +0200	[thread overview]
Message-ID: <20200407230647.59478-3-thomas@monjalon.net> (raw)
In-Reply-To: <20200407230647.59478-1-thomas@monjalon.net>

The variable storages of the same name are merged together
if compiled with -fcommon. This is the default.
This default behaviour allows to declare a variable in a header file
and share the variable in every .o binaries thanks to merge at link-time.

In the case of dlopen linking of the glue library, the pointer mlx5_glue
is referencing the glue functions struct and is set after calling dlopen.

If compiling with -fno-common (default in GCC 10), the variable
must be declared as extern to avoid multiple re-definitions.
In case the glue layer is split in glue library, the variable mlx5_glue
needs to have its own storage for the rest of the PMD.

Cc: stable@dpdk.org

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Matan Azrad <matan@mellanox.com>
---
 drivers/common/mlx5/mlx5_common.c | 3 +++
 drivers/common/mlx5/mlx5_glue.h   | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/common/mlx5/mlx5_common.c b/drivers/common/mlx5/mlx5_common.c
index 9a30e6e0aa..98a82c262f 100644
--- a/drivers/common/mlx5/mlx5_common.c
+++ b/drivers/common/mlx5/mlx5_common.c
@@ -18,6 +18,9 @@
 
 int mlx5_common_logtype;
 
+#ifdef MLX5_GLUE
+const struct mlx5_glue *mlx5_glue;
+#endif
 
 /**
  * Get PCI information by sysfs device path.
diff --git a/drivers/common/mlx5/mlx5_glue.h b/drivers/common/mlx5/mlx5_glue.h
index 6238b43946..29678623e4 100644
--- a/drivers/common/mlx5/mlx5_glue.h
+++ b/drivers/common/mlx5/mlx5_glue.h
@@ -300,6 +300,6 @@ struct mlx5_glue {
 			 size_t event_resp_len);
 };
 
-const struct mlx5_glue *mlx5_glue;
+extern const struct mlx5_glue *mlx5_glue;
 
 #endif /* MLX5_GLUE_H_ */
-- 
2.26.0


  parent reply	other threads:[~2020-04-07 23:07 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-10 10:32 [dpdk-dev] [PATCH 0/3] mlx: fix build with -fno-common (gcc 10) Thomas Monjalon
2020-02-10 10:32 ` [dpdk-dev] [PATCH 1/3] common/mlx5: split glue initialization Thomas Monjalon
2020-02-10 10:32 ` [dpdk-dev] [PATCH 2/3] common/mlx5: fix build with -fno-common Thomas Monjalon
2020-02-10 10:32 ` [dpdk-dev] [PATCH 3/3] net/mlx4: " Thomas Monjalon
2020-03-17  8:34 ` [dpdk-dev] [PATCH 0/3] mlx: fix build with -fno-common (gcc 10) Matan Azrad
2020-04-07  0:19   ` Thomas Monjalon
2020-04-07 23:06 ` [dpdk-dev] [PATCH v2 " Thomas Monjalon
2020-04-07 23:06   ` [dpdk-dev] [PATCH v2 1/3] common/mlx5: split glue initialization Thomas Monjalon
2020-04-07 23:06   ` Thomas Monjalon [this message]
2020-04-07 23:06   ` [dpdk-dev] [PATCH v2 3/3] net/mlx4: fix build with -fno-common Thomas Monjalon
2020-04-08  0:08 ` [dpdk-dev] [PATCH v3 0/3] mlx: fix build with -fno-common (gcc 10) Thomas Monjalon
2020-04-08  0:08   ` [dpdk-dev] [PATCH v3 1/3] common/mlx5: split glue initialization Thomas Monjalon
2020-04-08  0:08   ` [dpdk-dev] [PATCH v3 2/3] common/mlx5: fix build with -fno-common Thomas Monjalon
2020-04-08  0:09   ` [dpdk-dev] [PATCH v3 3/3] net/mlx4: " Thomas Monjalon
2020-04-12 15:51   ` [dpdk-dev] [PATCH v3 0/3] mlx: fix build with -fno-common (gcc 10) Raslan Darawsheh

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