From 9ff791eff609138a69edd89bf4abde71511eef6d Mon Sep 17 00:00:00 2001 From: Bruce Richardson Date: Mon, 8 Feb 2021 16:33:19 +0000 Subject: [PATCH] eal: fix automatic loading of drivers as shared libs When checking the loading of EAL shared lib to see if we have a shared DPDK build, we only want to include part of the ABI version in the check rather than the whole thing. For example, with ABI version 21.1 for DPDK release 21.02, the linker links the binary against librte_eal.so.21, without the ".1". To avoid any further brittleness in this area, we can check for multiple versions when doing the check, since just about any version of EAL implies a shared build. Therefore we check for presence of librte_eal.so with full ABI_VERSION extension, and then repeatedly remove the end part of the filename after the last dot, checking each time. For example (debug log output for static build): EAL: Checking presence of .so 'librte_eal.so.21.1' EAL: Checking presence of .so 'librte_eal.so.21' EAL: Checking presence of .so 'librte_eal.so' EAL: Detected static linkage of DPDK Fixes: 7781950f4d38 ("eal: fix shared lib mode detection") Cc: stable@dpdk.org Signed-off-by: Bruce Richardson Tested-by: Sunil Pai G --- lib/librte_eal/common/eal_common_options.c | 35 +++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) diff --git a/lib/librte_eal/common/eal_common_options.c b/lib/librte_eal/common/eal_common_options.c index 424e8bcf87..622c7bc429 100644 --- a/lib/librte_eal/common/eal_common_options.c +++ b/lib/librte_eal/common/eal_common_options.c @@ -494,6 +494,39 @@ out: return retval; } +static int +is_shared_build(void) +{ +#define EAL_SO "librte_eal.so" + char soname[32]; + size_t len, minlen = strlen(EAL_SO); + + len = strlcpy(soname, EAL_SO"."ABI_VERSION, sizeof(soname)); + if (len > sizeof(soname)) { + RTE_LOG(ERR, EAL, "Shared lib name too long in shared build check\n"); + len = sizeof(soname) - 1; + } + + while (len >= minlen) { + /* check if we have this .so loaded, if so - shared build */ + RTE_LOG(DEBUG, EAL, "Checking presence of .so '%s'\n", soname); + if (dlopen(soname, RTLD_LAZY | RTLD_NOLOAD) != NULL) { + RTE_LOG(INFO, EAL, "Detected shared linkage of DPDK\n"); + return 1; + } + + /* remove any version numbers off the end to retry */ + while (len-- > 0) + if (soname[len] == '.') { + soname[len] = '\0'; + break; + } + } + + RTE_LOG(INFO, EAL, "Detected static linkage of DPDK\n"); + return 0; +} + int eal_plugins_init(void) { @@ -505,7 +538,7 @@ eal_plugins_init(void) * (Using dlopen with NOLOAD flag on EAL, will return NULL if the EAL * shared library is not already loaded i.e. it's statically linked.) */ - if (dlopen("librte_eal.so."ABI_VERSION, RTLD_LAZY | RTLD_NOLOAD) != NULL && + if (is_shared_build() && *default_solib_dir != '\0' && stat(default_solib_dir, &sb) == 0 && S_ISDIR(sb.st_mode)) -- 2.20.1