From 5d61e71c3a8ac3296afbfe9a014c62050c5a9234 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Thu, 27 Sep 2007 10:09:59 +0000 Subject: introduce safe_poll (fixes a problem in top) function old new delta safe_poll - 77 +77 svlogd_main 1470 1466 -4 zcip_main 1530 1524 -6 forkexec 1345 1338 -7 decode_format_string 795 788 -7 collect_blk 474 467 -7 buffer_pread 540 532 -8 tftp 1182 1172 -10 microcom_main 763 749 -14 arpping 441 424 -17 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/9 up/down: 77/-80) Total: -3 bytes text data bss dec hex filename 770162 1034 10404 781600 bed20 busybox_old 770158 1034 10404 781596 bed1c busybox_unstripped --- libbb/Kbuild | 1 + libbb/safe_poll.c | 34 ++++++++++++++++++++++++++++++++++ libbb/safe_strncpy.c | 2 +- 3 files changed, 36 insertions(+), 1 deletion(-) create mode 100644 libbb/safe_poll.c (limited to 'libbb') diff --git a/libbb/Kbuild b/libbb/Kbuild index 1800bde8f..55b3658b4 100644 --- a/libbb/Kbuild +++ b/libbb/Kbuild @@ -71,6 +71,7 @@ lib-y += recursive_action.o lib-y += remove_file.o lib-y += restricted_shell.o lib-y += run_shell.o +lib-y += safe_poll.o lib-y += safe_strncpy.o lib-y += safe_write.o lib-y += setup_environment.o diff --git a/libbb/safe_poll.c b/libbb/safe_poll.c new file mode 100644 index 000000000..d2b773c36 --- /dev/null +++ b/libbb/safe_poll.c @@ -0,0 +1,34 @@ +/* vi: set sw=4 ts=4: */ +/* + * Utility routines. + * + * Copyright (C) 2007 by Denys Vlasenko + * + * Licensed under GPLv2, see file LICENSE in this tarball for details. + */ + +#include "libbb.h" + +/* Wrapper which restarts poll on EINTR or ENOMEM. + * On other errors does perror("poll") and returns. + * Warning! May take longer than timeout_ms to return! */ +int safe_poll(struct pollfd *ufds, nfds_t nfds, int timeout) +{ + while (1) { + int n = poll(ufds, nfds, timeout); + if (n >= 0) + return n; + /* Make sure we inch towards completion */ + if (timeout > 0) + timeout--; + /* E.g. strace causes poll to return this */ + if (errno == EINTR) + continue; + /* Kernel is very low on memory. Retry. */ + /* I doubt many callers would handle this correctly! */ + if (errno == ENOMEM) + continue; + bb_perror_msg("poll"); + return n; + } +} diff --git a/libbb/safe_strncpy.c b/libbb/safe_strncpy.c index ebc7e28f3..cc425839f 100644 --- a/libbb/safe_strncpy.c +++ b/libbb/safe_strncpy.c @@ -10,7 +10,7 @@ #include "libbb.h" /* Like strncpy but make sure the resulting string is always 0 terminated. */ -char * safe_strncpy(char *dst, const char *src, size_t size) +char *safe_strncpy(char *dst, const char *src, size_t size) { if (!size) return dst; dst[--size] = '\0'; -- cgit v1.2.3