From 5d61e71c3a8ac3296afbfe9a014c62050c5a9234 Mon Sep 17 00:00:00 2001
From: Denis Vlasenko <vda.linux@googlemail.com>
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 <vda.linux@googlemail.com>
+ *
+ * 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';
--
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