diff options
author | Denis Vlasenko <vda.linux@googlemail.com> | 2007-09-27 14:09:59 +0400 |
---|---|---|
committer | Denis Vlasenko <vda.linux@googlemail.com> | 2007-09-27 14:09:59 +0400 |
commit | 5d61e71c3a8ac3296afbfe9a014c62050c5a9234 (patch) | |
tree | e9ab2cd35d1f2d51b26a678551a0439b1719928b | |
parent | c9dc2ac578278e86be248cc21e53081f7054da83 (diff) |
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
-rw-r--r-- | editors/vi.c | 4 | ||||
-rw-r--r-- | include/libbb.h | 8 | ||||
-rw-r--r-- | libbb/Kbuild | 1 | ||||
-rw-r--r-- | libbb/safe_poll.c | 34 | ||||
-rw-r--r-- | libbb/safe_strncpy.c | 2 | ||||
-rw-r--r-- | miscutils/microcom.c | 3 | ||||
-rw-r--r-- | networking/httpd.c | 6 | ||||
-rw-r--r-- | networking/tftp.c | 4 | ||||
-rw-r--r-- | networking/traceroute.c | 2 | ||||
-rw-r--r-- | networking/udhcp/arpping.c | 7 | ||||
-rw-r--r-- | networking/zcip.c | 14 | ||||
-rw-r--r-- | procps/top.c | 2 | ||||
-rw-r--r-- | runit/svlogd.c | 8 |
13 files changed, 65 insertions, 30 deletions
diff --git a/editors/vi.c b/editors/vi.c index f5df41636..1fa7c3a09 100644 --- a/editors/vi.c +++ b/editors/vi.c @@ -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) diff --git a/include/libbb.h b/include/libbb.h index 407b723b2..26a0f0d4a 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -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); 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'; diff --git a/miscutils/microcom.c b/miscutils/microcom.c index 59a91024e..5928569d5 100644 --- a/miscutils/microcom.c +++ b/miscutils/microcom.c @@ -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); diff --git a/networking/httpd.c b/networking/httpd.c index cedec800f..92a07107d 100644 --- a/networking/httpd.c +++ b/networking/httpd.c @@ -1073,13 +1073,9 @@ 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 * are ready, yet poll returned?! */ diff --git a/networking/tftp.c b/networking/tftp.c index ac3a86afb..59f53ae4a 100644 --- a/networking/tftp.c +++ b/networking/tftp.c @@ -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: diff --git a/networking/traceroute.c b/networking/traceroute.c index 21921e56d..2d09c7197 100644 --- a/networking/traceroute.c +++ b/networking/traceroute.c @@ -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; diff --git a/networking/udhcp/arpping.c b/networking/udhcp/arpping.c index 33518077b..7b702d8f3 100644 --- a/networking/udhcp/arpping.c +++ b/networking/udhcp/arpping.c @@ -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; diff --git a/networking/zcip.c b/networking/zcip.c index 2f0b5a7fb..63846ebef 100644 --- a/networking/zcip.c +++ b/networking/zcip.c @@ -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; diff --git a/procps/top.c b/procps/top.c index ac3b7e5a2..e55cecccb 100644 --- a/procps/top.c +++ b/procps/top.c @@ -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]) diff --git a/runit/svlogd.c b/runit/svlogd.c index 6c8747e96..b5eed15ab 100644 --- a/runit/svlogd.c +++ b/runit/svlogd.c @@ -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'; |