From 08c028d08c42c1a4cd26aff1ed9c6438ddfd1206 Mon Sep 17 00:00:00 2001 From: Adrien Mazarguil 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 Signed-off-by: Adrien Mazarguil Tested-by: Timothy Redaelli --- 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 98b9716672..afeff276eb 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 0e6e525c91..46d26e4c8a 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 ee93dafe66..fb8a8b8484 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 61cb93101a..0ca16d11d7 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; -- 2.20.1