From 0cc2ed4bab5f24d02f1bc2af0820c64ff0da24aa Mon Sep 17 00:00:00 2001 From: Martin Quinson Date: Thu, 20 Apr 2017 15:43:58 +0200 Subject: [PATCH] dlopen: give one fdin per thread to avoid stupid races resulting in empty copied files --- src/smpi/smpi_global.cpp | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/src/smpi/smpi_global.cpp b/src/smpi/smpi_global.cpp index 28b374d1c7..9b6cb53df9 100644 --- a/src/smpi/smpi_global.cpp +++ b/src/smpi/smpi_global.cpp @@ -554,28 +554,26 @@ int smpi_main(const char* executable, int argc, char *argv[]) std::string executable_copy = executable; - // Prepare the copy of the binary (open the file and get its size) - // (fdin will remain open for the whole process execution. That's a sort of leak but we can live with it) - int fdin = open(executable_copy.c_str(), O_RDONLY); - xbt_assert(fdin >= 0, "Cannot read from %s", executable_copy.c_str()); + // Prepare the copy of the binary (get its size) struct stat fdin_stat; - fstat(fdin, &fdin_stat); + stat(executable_copy.c_str(), &fdin_stat); off_t fdin_size = fdin_stat.st_size; - simix_global->default_function = [executable_copy, fdin, fdin_size](std::vector args) { - return std::function([executable_copy, fdin, fdin_size, args] { + simix_global->default_function = [executable_copy, fdin_size](std::vector args) { + return std::function([executable_copy, fdin_size, args] { // Copy the dynamic library: std::string target_executable = executable_copy + "_" + std::to_string(getpid()) + "_" + std::to_string(rank++) + ".so"; + int fdin = open(executable_copy.c_str(), O_RDONLY); + xbt_assert(fdin >= 0, "Cannot read from %s", executable_copy.c_str()); int fdout = open(target_executable.c_str(), O_CREAT | O_RDWR, S_IRWXU); xbt_assert(fdout >= 0, "Cannot write into %s", target_executable.c_str()); #if HAVE_SENDFILE - off_t offset = 0; - sendfile(fdout, fdin, &offset, fdin_size); + sendfile(fdout, fdin, NULL, fdin_size); #else XBT_WARN("Copy %d bytes into %s", static_cast(fdin_size), target_executable.c_str()); const int bufsize = 1024 * 1024 * 4; @@ -597,6 +595,7 @@ int smpi_main(const char* executable, int argc, char *argv[]) } } #endif + close(fdin); close(fdout); // Load the copy and resolve the entry point: -- 2.20.1