diff -up libgcrypt-1.7.6/random/rndlinux.c.use-poll libgcrypt-1.7.6/random/rndlinux.c --- libgcrypt-1.7.6/random/rndlinux.c.use-poll 2017-01-30 14:20:13.665662981 +0100 +++ libgcrypt-1.7.6/random/rndlinux.c 2017-01-30 14:27:45.957027214 +0100 @@ -32,6 +32,7 @@ #include #include #include +#include #if defined(__linux__) && defined(HAVE_SYSCALL) # include #endif @@ -211,9 +212,8 @@ _gcry_rndlinux_gather_random (void (*add return with something we will actually use 100ms. */ while (length) { - fd_set rfds; - struct timeval tv; int rc; + struct pollfd pfd; /* If we have a modern Linux kernel and we want to read from the * the non-blocking /dev/urandom, we first try to use the new @@ -269,33 +269,22 @@ _gcry_rndlinux_gather_random (void (*add any_need_entropy = 1; } - /* If the system has no limit on the number of file descriptors - and we encounter an fd which is larger than the fd_set size, - we don't use the select at all. The select code is only used - to emit progress messages. A better solution would be to - fall back to poll() if available. */ -#ifdef FD_SETSIZE - if (fd < FD_SETSIZE) -#endif + pfd.fd = fd; + pfd.events = POLLIN; + + if ( !(rc=poll(&pfd, 1, delay)) ) { - FD_ZERO(&rfds); - FD_SET(fd, &rfds); - tv.tv_sec = delay; - tv.tv_usec = delay? 0 : 100000; - if ( !(rc=select(fd+1, &rfds, NULL, NULL, &tv)) ) - { - any_need_entropy = 1; - delay = 3; /* Use 3 seconds henceforth. */ - continue; - } - else if( rc == -1 ) - { - log_error ("select() error: %s\n", strerror(errno)); - if (!delay) - delay = 1; /* Use 1 second if we encounter an error before - we have ever blocked. */ - continue; - } + any_need_entropy = 1; + delay = 3000; /* Use 3 seconds henceforth. */ + continue; + } + else if( rc == -1 ) + { + log_error ("poll() error: %s\n", strerror(errno)); + if (!delay) + delay = 1000; /* Use 1 second if we encounter an error before + we have ever blocked. */ + continue; } /* Read from the device. */