From 5c0aa72a4999bdcf03fe93ed5c8213c2b4c681f0 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 2 Apr 2013 16:31:55 +0200 Subject: [PATCH] util: add a bit of syntactic sugar for saving/restoring errno --- src/journal/journal-send.c | 94 ++++++++++++-------------------------- src/shared/log.c | 31 ++++--------- src/shared/util.c | 4 +- src/shared/util.h | 6 +++ 4 files changed, 44 insertions(+), 91 deletions(-) diff --git a/src/journal/journal-send.c b/src/journal/journal-send.c index d5ec73e37..4b9109a3c 100644 --- a/src/journal/journal-send.c +++ b/src/journal/journal-send.c @@ -112,12 +112,11 @@ _public_ int sd_journal_printv(int priority, const char *format, va_list ap) { } static int fill_iovec_sprintf(const char *format, va_list ap, int extra, struct iovec **_iov) { + PROTECT_ERRNO; int r, n = 0, i = 0, j; struct iovec *iov = NULL; - int saved_errno; assert(_iov); - saved_errno = errno; if (extra > 0) { n = MAX(extra * 2, extra + 4); @@ -163,7 +162,6 @@ static int fill_iovec_sprintf(const char *format, va_list ap, int extra, struct *_iov = iov; - errno = saved_errno; return i; fail: @@ -172,7 +170,6 @@ fail: free(iov); - errno = saved_errno; return r; } @@ -202,14 +199,14 @@ finish: } _public_ int sd_journal_sendv(const struct iovec *iov, int n) { + PROTECT_ERRNO; int fd, buffer_fd; struct iovec *w; uint64_t *l; - int r, i, j = 0; + int i, j = 0; struct msghdr mh; struct sockaddr_un sa; ssize_t k; - int saved_errno; union { struct cmsghdr cmsghdr; uint8_t buf[CMSG_SPACE(sizeof(int))]; @@ -227,24 +224,18 @@ _public_ int sd_journal_sendv(const struct iovec *iov, int n) { if (_unlikely_(n <= 0)) return -EINVAL; - saved_errno = errno; - w = alloca(sizeof(struct iovec) * n * 5 + 3); l = alloca(sizeof(uint64_t) * n); for (i = 0; i < n; i++) { char *c, *nl; - if (_unlikely_(!iov[i].iov_base || iov[i].iov_len <= 1)) { - r = -EINVAL; - goto finish; - } + if (_unlikely_(!iov[i].iov_base || iov[i].iov_len <= 1)) + return -EINVAL; c = memchr(iov[i].iov_base, '=', iov[i].iov_len); - if (_unlikely_(!c || c == iov[i].iov_base)) { - r = -EINVAL; - goto finish; - } + if (_unlikely_(!c || c == iov[i].iov_base)) + return -EINVAL; have_syslog_identifier = have_syslog_identifier || (c == (char *) iov[i].iov_base + 17 && @@ -252,10 +243,8 @@ _public_ int sd_journal_sendv(const struct iovec *iov, int n) { nl = memchr(iov[i].iov_base, '\n', iov[i].iov_len); if (nl) { - if (_unlikely_(nl < c)) { - r = -EINVAL; - goto finish; - } + if (_unlikely_(nl < c)) + return -EINVAL; /* Already includes a newline? Bummer, then * let's write the variable name, then a @@ -300,10 +289,8 @@ _public_ int sd_journal_sendv(const struct iovec *iov, int n) { } fd = journal_fd(); - if (_unlikely_(fd < 0)) { - r = fd; - goto finish; - } + if (_unlikely_(fd < 0)) + return fd; zero(sa); sa.sun_family = AF_UNIX; @@ -316,37 +303,29 @@ _public_ int sd_journal_sendv(const struct iovec *iov, int n) { mh.msg_iovlen = j; k = sendmsg(fd, &mh, MSG_NOSIGNAL); - if (k >= 0) { - r = 0; - goto finish; - } + if (k >= 0) + return 0; - if (errno != EMSGSIZE && errno != ENOBUFS) { - r = -errno; - goto finish; - } + if (errno != EMSGSIZE && errno != ENOBUFS) + return -errno; /* Message doesn't fit... Let's dump the data in a temporary * file and just pass a file descriptor of it to the other * side */ buffer_fd = mkostemp(path, O_CLOEXEC|O_RDWR); - if (buffer_fd < 0) { - r = -errno; - goto finish; - } + if (buffer_fd < 0) + return -errno; if (unlink(path) < 0) { close_nointr_nofail(buffer_fd); - r = -errno; - goto finish; + return -errno; } n = writev(buffer_fd, w, j); if (n < 0) { close_nointr_nofail(buffer_fd); - r = -errno; - goto finish; + return -errno; } mh.msg_iov = NULL; @@ -367,24 +346,15 @@ _public_ int sd_journal_sendv(const struct iovec *iov, int n) { k = sendmsg(fd, &mh, MSG_NOSIGNAL); close_nointr_nofail(buffer_fd); - if (k < 0) { - r = -errno; - goto finish; - } - - r = 0; - -finish: - errno = saved_errno; + if (k < 0) + return -errno; - return r; + return 0; } static int fill_iovec_perror_and_send(const char *message, int skip, struct iovec iov[]) { - size_t n, k, r; - int saved_errno; - - saved_errno = errno; + PROTECT_ERRNO; + size_t n, k; k = isempty(message) ? 0 : strlen(message) + 2; n = 8 + k + 256 + 1; @@ -394,7 +364,7 @@ static int fill_iovec_perror_and_send(const char *message, int skip, struct iove char* j; errno = 0; - j = strerror_r(saved_errno, buffer + 8 + k, n - 8 - k); + j = strerror_r(_saved_errno_, buffer + 8 + k, n - 8 - k); if (errno == 0) { char error[6 + 10 + 1]; /* for a 32bit value */ @@ -408,24 +378,18 @@ static int fill_iovec_perror_and_send(const char *message, int skip, struct iove memcpy(buffer + 8 + k - 2, ": ", 2); } - snprintf(error, sizeof(error), "ERRNO=%u", saved_errno); + snprintf(error, sizeof(error), "ERRNO=%u", _saved_errno_); char_array_0(error); IOVEC_SET_STRING(iov[skip+0], "PRIORITY=3"); IOVEC_SET_STRING(iov[skip+1], buffer); IOVEC_SET_STRING(iov[skip+2], error); - r = sd_journal_sendv(iov, skip + 3); - - errno = saved_errno; - return r; + return sd_journal_sendv(iov, skip + 3); } - if (errno != ERANGE) { - r = -errno; - errno = saved_errno; - return r; - } + if (errno != ERANGE) + return -errno; n *= 2; } diff --git a/src/shared/log.c b/src/shared/log.c index 293c261f9..0dd04bc51 100644 --- a/src/shared/log.c +++ b/src/shared/log.c @@ -598,18 +598,14 @@ int log_dump_internal( const char *func, char *buffer) { - int saved_errno, r; + PROTECT_ERRNO; /* This modifies the buffer... */ if (_likely_(LOG_PRI(level) > log_max_level)) return 0; - saved_errno = errno; - r = log_dispatch(level, file, line, func, NULL, NULL, buffer); - errno = saved_errno; - - return r; + return log_dispatch(level, file, line, func, NULL, NULL, buffer); } int log_metav( @@ -620,20 +616,16 @@ int log_metav( const char *format, va_list ap) { + PROTECT_ERRNO; char buffer[LINE_MAX]; - int saved_errno, r; if (_likely_(LOG_PRI(level) > log_max_level)) return 0; - saved_errno = errno; vsnprintf(buffer, sizeof(buffer), format, ap); char_array_0(buffer); - r = log_dispatch(level, file, line, func, NULL, NULL, buffer); - errno = saved_errno; - - return r; + return log_dispatch(level, file, line, func, NULL, NULL, buffer); } int log_meta( @@ -663,21 +655,17 @@ int log_metav_object( const char *format, va_list ap) { + PROTECT_ERRNO; char buffer[LINE_MAX]; - int saved_errno, r; if (_likely_(LOG_PRI(level) > log_max_level)) return 0; - saved_errno = errno; vsnprintf(buffer, sizeof(buffer), format, ap); char_array_0(buffer); - r = log_dispatch(level, file, line, func, - object_name, object, buffer); - errno = saved_errno; - - return r; + return log_dispatch(level, file, line, func, + object_name, object, buffer); } int log_meta_object( @@ -735,7 +723,7 @@ int log_struct_internal( const char *func, const char *format, ...) { - int saved_errno; + PROTECT_ERRNO; va_list ap; int r; @@ -748,8 +736,6 @@ int log_struct_internal( if ((level & LOG_FACMASK) == 0) level = log_facility | LOG_PRI(level); - saved_errno = errno; - if ((log_target == LOG_TARGET_AUTO || log_target == LOG_TARGET_JOURNAL_OR_KMSG || log_target == LOG_TARGET_JOURNAL) && @@ -843,7 +829,6 @@ int log_struct_internal( r = -EINVAL; } - errno = saved_errno; return r; } diff --git a/src/shared/util.c b/src/shared/util.c index 46c20bec9..b69e7e882 100644 --- a/src/shared/util.c +++ b/src/shared/util.c @@ -207,14 +207,12 @@ int close_nointr(int fd) { } void close_nointr_nofail(int fd) { - int saved_errno = errno; + PROTECT_ERRNO; /* like close_nointr() but cannot fail, and guarantees errno * is unchanged */ assert_se(close_nointr(fd) == 0); - - errno = saved_errno; } void close_many(const int fds[], unsigned n_fd) { diff --git a/src/shared/util.h b/src/shared/util.h index d1cdd901a..7f050758a 100644 --- a/src/shared/util.h +++ b/src/shared/util.h @@ -615,3 +615,9 @@ char *strextend(char **x, ...); char *strrep(const char *s, unsigned n); void* greedy_realloc(void **p, size_t *allocated, size_t need); + +static inline void reset_errno(int *saved_errno) { + errno = *saved_errno; +} + +#define PROTECT_ERRNO __attribute__((cleanup(reset_errno))) int _saved_errno_ = errno -- 2.30.2