5d61e71c3

Denis Vlasenko

2007-09-27

FAILED Duration: 23s

Subject

introduce safe_poll (fixes a problem in top)

No binary (build failed)

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

(log yok)

editors/vi.c+2 -2

@@ -2139,7 +2139,7 @@ static int mysleep(int hund) // sleep for 'h' 1/100 seconds

	pfd[0].fd = 0;
	pfd[0].events = POLLIN;
-	return poll(pfd, 1, hund*10) > 0;
+	return safe_poll(pfd, 1, hund*10) > 0;
	}

	#define readbuffer bb_common_bufsiz1
@@ -2221,7 +2221,7 @@ static char readit(void) // read (maybe cursor) key from stdin
	pfd[0].events = POLLIN;
	// Wait 50 ms
	// keep reading while there are input chars and room in buffer
-	while (poll(pfd, 1, 50) > 0 && n <= (MAX_LINELEN - 5)) {
+	while (safe_poll(pfd, 1, 50) > 0 && n <= (MAX_LINELEN - 5)) {
	// read the rest of the ESC string
	int r = read(0, readbuffer + n, MAX_LINELEN - n);
	if (r > 0)

include/libbb.h+7 -1

@@ -451,8 +451,14 @@ extern FILE fopen_or_warn(const char filename, const char *mode);
	/* "Opens" stdin if filename is special, else just opens file: */
	extern FILE fopen_or_warn_stdin(const char filename);

+	/* Wrapper which restarts poll on EINTR or ENOMEM.
+	* On other errors complains [perror("poll")] and returns.
+	* Warning! May take (much) longer than timeout_ms to return!
+	* If this is a problem, use bare poll and open-code EINTR/ENOMEM handling */
+	int safe_poll(struct pollfd *ufds, nfds_t nfds, int timeout_ms);
+
	/* Convert each alpha char in str to lower-case */
-	extern char* str_tolower(char *str);
+	char* str_tolower(char *str);

	char *utoa(unsigned n);
	char *itoa(int n);

libbb/Kbuild+1 -0

libbb/safe_poll.c+34 -0

@@ -0,0 +1,34 @@
+	/* vi: set sw=4 ts=4: */
+	/*
+	* Utility routines.
+	*
+	* Copyright (C) 2007 by Denys Vlasenko <[email protected]>
+	*
+	* 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;
+	}
+	}

libbb/safe_strncpy.c+1 -1

@@ -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';

miscutils/microcom.c+1 -2

@@ -105,8 +105,7 @@ int microcom_main(int argc, char **argv)
	pfd[1].events = POLLIN;
	while (1) {
	int i;
-	while (-1 == poll(pfd, 2, -1) && EINTR == errno)
-	continue;
+	safe_poll(pfd, 2, -1);
	for (i = 0; i < 2; ++i) {
	if (pfd[i].revents & POLLIN) {
	len = read(pfd[i].fd, bb_common_bufsiz1, COMMON_BUFSIZE);

networking/httpd.c+1 -5

@@ -1073,12 +1073,8 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
	}

	/* Now wait on the set of sockets */
-	count = poll(pfd, 3, -1);
+	count = safe_poll(pfd, 3, -1);
	if (count <= 0) {
-	#if 0
-	if (errno == EINTR)
-	continue;
-	#endif
	#if 0
	if (waitpid(pid, &status, WNOHANG) <= 0) {
	/* Weird. CGI didn't exit and no fd's

networking/tftp.c+2 -2

@@ -225,7 +225,7 @@ static int tftp( USE_GETPUT(const int cmd,)
	/* Receive packet */
	/pfd[0].fd = socketfd;/
	pfd[0].events = POLLIN;
-	switch (poll(pfd, 1, waittime_ms)) {
+	switch (safe_poll(pfd, 1, waittime_ms)) {
	unsigned from_port;
	case 1:
	from->len = peer_lsa->len;
@@ -262,7 +262,7 @@ static int tftp( USE_GETPUT(const int cmd,)

	goto send_again; /* resend last sent pkt */
	default:
-	bb_perror_msg("poll");
+	/bb_perror_msg("poll"); - done in safe_poll /
	goto ret;
	}
	process_pkt:

networking/traceroute.c+1 -1

@@ -543,7 +543,7 @@ wait_for_reply(int sock, struct sockaddr_in *fromp)

	pfd[0].fd = sock;
	pfd[0].events = POLLIN;
-	if (poll(pfd, 1, waittime * 1000) > 0)
+	if (safe_poll(pfd, 1, waittime * 1000) > 0)
	cc = recvfrom(sock, packet, sizeof(packet), 0,
	(struct sockaddr *)fromp, &fromlen);
	return cc;

networking/udhcp/arpping.c+2 -5

@@ -81,12 +81,9 @@ int arpping(uint32_t test_ip, uint32_t from_ip, uint8_t from_mac, const char i
	unsigned prevTime = monotonic_us();

	pfd[0].events = POLLIN;
-	r = poll(pfd, 1, timeout_ms);
+	r = safe_poll(pfd, 1, timeout_ms);
	if (r < 0) {
-	if (errno != EINTR) {
-	bb_perror_msg("poll");
-	break;
-	}
+	break;
	} else if (r) {
	if (read(s, &arp, sizeof(arp)) < 0)
	break;

networking/zcip.c+8 -6

@@ -300,7 +300,12 @@ int zcip_main(int argc, char **argv)

	VDBG("...wait %d %s nprobes=%u, nclaims=%u\n",
	timeout_ms, intf, nprobes, nclaims);
-	switch (poll(fds, 1, timeout_ms)) {
+
+	switch (safe_poll(fds, 1, timeout_ms)) {
+
+	default:
+	/bb_perror_msg("poll"); - done in safe_poll /
+	return EXIT_FAILURE;

	// timeout
	case 0:
@@ -388,6 +393,7 @@ int zcip_main(int argc, char **argv)
	break;
	} // switch (state)
	break; // case 0 (timeout)
+
	// packets arriving
	case 1:
	// We need to adjust the timeout in case we didn't receive
@@ -519,13 +525,9 @@ int zcip_main(int argc, char **argv)
	nclaims = 0;
	break;
	} // switch state
-
	break; // case 1 (packets arriving)
-	default:
-	why = "poll";
-	goto bad;
	} // switch poll
-	}
+	} // while (1)
	bad:
	bb_perror_msg("%s, %s", intf, why);
	return EXIT_FAILURE;

procps/top.c+1 -1

@@ -924,7 +924,7 @@ int top_main(int argc, char **argv)
	#if !ENABLE_FEATURE_USE_TERMIOS
	sleep(interval);
	#else
-	if (poll(pfd, 1, interval * 1000) != 0) {
+	if (safe_poll(pfd, 1, interval * 1000) > 0) {
	if (read(0, &c, 1) != 1) /* signal */
	break;
	if (c == initial_settings.c_cc[VINTR])

runit/svlogd.c+4 -4

@@ -665,7 +665,7 @@ static ssize_t ndelay_read(int fd, void *buf, size_t count)
	}

	/* Used for reading stdin */
-	static int buffer_pread(int fd, char *s, unsigned len)
+	static int buffer_pread(/int fd, /char *s, unsigned len)
	{
	unsigned now;
	struct pollfd input;
@@ -709,7 +709,7 @@ static int buffer_pread(int fd, char *s, unsigned len)
	poll(&input, 1, i * 1000);
	sigprocmask(SIG_BLOCK, blocked_sigset, NULL);

-	i = ndelay_read(fd, s, len);
+	i = ndelay_read(0, s, len);
	if (i >= 0)
	break;
	if (errno == EINTR)
@@ -909,7 +909,7 @@ int svlogd_main(int argc, char **argv)
	if (!np && !exitasap) {
	i = linemax - stdin_cnt; /* avail. bytes at tail */
	if (i >= 128) {
-	i = buffer_pread(0, lineptr + stdin_cnt, i);
+	i = buffer_pread(/0, /lineptr + stdin_cnt, i);
	if (i <= 0) /* EOF or error on stdin */
	exitasap = 1;
	else {
@@ -966,7 +966,7 @@ int svlogd_main(int argc, char **argv)
	/* read/write repeatedly until we see it */
	while (ch != '\n') {
	/* lineptr is emptied now, safe to use as buffer */
-	stdin_cnt = exitasap ? -1 : buffer_pread(0, lineptr, linemax);
+	stdin_cnt = exitasap ? -1 : buffer_pread(/0, /lineptr, linemax);
	if (stdin_cnt <= 0) { /* EOF or error on stdin */
	exitasap = 1;
	lineptr[0] = ch = '\n';