From 08c028d08c42c1a4cd26aff1ed9c6438ddfd1206 Mon Sep 17 00:00:00 2001
From: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Date: Fri, 2 Mar 2018 15:15:17 +0100
Subject: [PATCH] net/mlx: fix rdma-core glue path with EAL plugins
Glue object files are looked up in RTE_EAL_PMD_PATH by default when set and
should be installed in this directory.
During startup, EAL attempts to load them automatically like other plug-ins
found there. While normally harmless, dlopen() fails when rdma-core is not
installed, EAL interprets this as a fatal error and terminates the
application.
This patch requests glue objects to be installed in a different directory
to prevent their automatic loading by EAL since they are PMD helpers, not
actual DPDK plug-ins.
Fixes: f6242d0655cd ("net/mlx: make rdma-core glue path configurable")
Cc: stable@dpdk.org
Reported-by: Timothy Redaelli <tredaelli@redhat.com>
Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Tested-by: Timothy Redaelli <tredaelli@redhat.com>
---
doc/guides/nics/mlx4.rst | 7 +++---
doc/guides/nics/mlx5.rst | 7 +++---
drivers/net/mlx4/mlx4.c | 50 +++++++++++++++++++++++++++++++++++++++-
drivers/net/mlx5/mlx5.c | 50 +++++++++++++++++++++++++++++++++++++++-
4 files changed, 106 insertions(+), 8 deletions(-)
diff --git a/doc/guides/nics/mlx4.rst b/doc/guides/nics/mlx4.rst
index 98b971667..afeff276e 100644
--- a/doc/guides/nics/mlx4.rst
+++ b/doc/guides/nics/mlx4.rst
@@ -98,9 +98,10 @@ These options can be modified in the ``.config`` file.
missing with ``ldd(1)``.
It works by moving these dependencies to a purpose-built rdma-core "glue"
- plug-in, which must either be installed in ``CONFIG_RTE_EAL_PMD_PATH`` if
- set, or in a standard location for the dynamic linker (e.g. ``/lib``) if
- left to the default empty string (``""``).
+ plug-in which must either be installed in a directory whose name is based
+ on ``CONFIG_RTE_EAL_PMD_PATH`` suffixed with ``-glue`` if set, or in a
+ standard location for the dynamic linker (e.g. ``/lib``) if left to the
+ default empty string (``""``).
This option has no performance impact.
diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index 0e6e525c9..46d26e4c8 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -171,9 +171,10 @@ These options can be modified in the ``.config`` file.
missing with ``ldd(1)``.
It works by moving these dependencies to a purpose-built rdma-core "glue"
- plug-in, which must either be installed in ``CONFIG_RTE_EAL_PMD_PATH`` if
- set, or in a standard location for the dynamic linker (e.g. ``/lib``) if
- left to the default empty string (``""``).
+ plug-in which must either be installed in a directory whose name is based
+ on ``CONFIG_RTE_EAL_PMD_PATH`` suffixed with ``-glue`` if set, or in a
+ standard location for the dynamic linker (e.g. ``/lib``) if left to the
+ default empty string (``""``).
This option has no performance impact.
diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
index ee93dafe6..fb8a8b848 100644
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -707,12 +707,54 @@ static struct rte_pci_driver mlx4_driver = {
#ifdef RTE_LIBRTE_MLX4_DLOPEN_DEPS
+/**
+ * Suffix RTE_EAL_PMD_PATH with "-glue".
+ *
+ * This function performs a sanity check on RTE_EAL_PMD_PATH before
+ * suffixing its last component.
+ *
+ * @param buf[out]
+ * Output buffer, should be large enough otherwise NULL is returned.
+ * @param size
+ * Size of @p out.
+ *
+ * @return
+ * Pointer to @p buf or @p NULL in case suffix cannot be appended.
+ */
+static char *
+mlx4_glue_path(char *buf, size_t size)
+{
+ static const char *const bad[] = { "/", ".", "..", NULL };
+ const char *path = RTE_EAL_PMD_PATH;
+ size_t len = strlen(path);
+ size_t off;
+ int i;
+
+ while (len && path[len - 1] == '/')
+ --len;
+ for (off = len; off && path[off - 1] != '/'; --off)
+ ;
+ for (i = 0; bad[i]; ++i)
+ if (!strncmp(path + off, bad[i], (int)(len - off)))
+ goto error;
+ i = snprintf(buf, size, "%.*s-glue", (int)len, path);
+ if (i == -1 || (size_t)i >= size)
+ goto error;
+ return buf;
+error:
+ ERROR("unable to append \"-glue\" to last component of"
+ " RTE_EAL_PMD_PATH (\"" RTE_EAL_PMD_PATH "\"),"
+ " please re-configure DPDK");
+ return NULL;
+}
+
/**
* Initialization routine for run-time dependency on rdma-core.
*/
static int
mlx4_glue_init(void)
{
+ char glue_path[sizeof(RTE_EAL_PMD_PATH) - 1 + sizeof("-glue")];
const char *path[] = {
/*
* A basic security check is necessary before trusting
@@ -720,7 +762,13 @@ mlx4_glue_init(void)
*/
(geteuid() == getuid() && getegid() == getgid() ?
getenv("MLX4_GLUE_PATH") : NULL),
- RTE_EAL_PMD_PATH,
+ /*
+ * When RTE_EAL_PMD_PATH is set, use its glue-suffixed
+ * variant, otherwise let dlopen() look up libraries on its
+ * own.
+ */
+ (*RTE_EAL_PMD_PATH ?
+ mlx4_glue_path(glue_path, sizeof(glue_path)) : ""),
};
unsigned int i = 0;
void *handle = NULL;
diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index 61cb93101..0ca16d11d 100644
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -1042,12 +1042,54 @@ static struct rte_pci_driver mlx5_driver = {
#ifdef RTE_LIBRTE_MLX5_DLOPEN_DEPS
+/**
+ * Suffix RTE_EAL_PMD_PATH with "-glue".
+ *
+ * This function performs a sanity check on RTE_EAL_PMD_PATH before
+ * suffixing its last component.
+ *
+ * @param buf[out]
+ * Output buffer, should be large enough otherwise NULL is returned.
+ * @param size
+ * Size of @p out.
+ *
+ * @return
+ * Pointer to @p buf or @p NULL in case suffix cannot be appended.
+ */
+static char *
+mlx5_glue_path(char *buf, size_t size)
+{
+ static const char *const bad[] = { "/", ".", "..", NULL };
+ const char *path = RTE_EAL_PMD_PATH;
+ size_t len = strlen(path);
+ size_t off;
+ int i;
+
+ while (len && path[len - 1] == '/')
+ --len;
+ for (off = len; off && path[off - 1] != '/'; --off)
+ ;
+ for (i = 0; bad[i]; ++i)
+ if (!strncmp(path + off, bad[i], (int)(len - off)))
+ goto error;
+ i = snprintf(buf, size, "%.*s-glue", (int)len, path);
+ if (i == -1 || (size_t)i >= size)
+ goto error;
+ return buf;
+error:
+ ERROR("unable to append \"-glue\" to last component of"
+ " RTE_EAL_PMD_PATH (\"" RTE_EAL_PMD_PATH "\"),"
+ " please re-configure DPDK");
+ return NULL;
+}
+
/**
* Initialization routine for run-time dependency on rdma-core.
*/
static int
mlx5_glue_init(void)
{
+ char glue_path[sizeof(RTE_EAL_PMD_PATH) - 1 + sizeof("-glue")];
const char *path[] = {
/*
* A basic security check is necessary before trusting
@@ -1055,7 +1097,13 @@ mlx5_glue_init(void)
*/
(geteuid() == getuid() && getegid() == getgid() ?
getenv("MLX5_GLUE_PATH") : NULL),
- RTE_EAL_PMD_PATH,
+ /*
+ * When RTE_EAL_PMD_PATH is set, use its glue-suffixed
+ * variant, otherwise let dlopen() look up libraries on its
+ * own.
+ */
+ (*RTE_EAL_PMD_PATH ?
+ mlx5_glue_path(glue_path, sizeof(glue_path)) : ""),
};
unsigned int i = 0;
void *handle = NULL;
--
2.17.0