* NEWS: Mention this.
* zic.c (verror, make_links, main, get_rand_u64)
(random_dirent, open_outfile, dolink, inputline, infile):
Be better about checking for signals, e.g., when the input or
the random number generator is giving is trouble, so that
it’s easier for the user to control-C out.
Although the result is not perfect it should be good
enough for practical use.
---
NEWS | 2 ++
zic.c | 35 ++++++++++++++++++++++-------------
2 files changed, 24 insertions(+), 13 deletions(-)
diff --git a/NEWS b/NEWS
index d4ba011b..fa791cb9 100644
--- a/NEWS
+++ b/NEWS
@@ -28,6 +28,8 @@ Unreleased, experimental changes
which can occur with adversarial input. (Thanks to GitHub
user rootvector2.)
+ zic now checks for signals more often.
+
Release 2026a - 2026-03-01 22:59:49 -0800
diff --git a/zic.c b/zic.c
index 77396228..c0891001 100644
--- a/zic.c
+++ b/zic.c
@@ -253,6 +253,7 @@ symlink(char const *target, char const *linkname)
(errno = ENOTSUP, -1)
#endif
+static void check_for_signal(void);
static void addtt(zic_t starttime, int type);
static int addtype(zic_t, char const *, bool, bool, bool);
static void leapadd(zic_t, int, int);
@@ -704,6 +705,7 @@ eat(int fnum, lineno num)
ATTRIBUTE_FORMAT((printf, 1, 0)) static void
verror(const char *const string, va_list args)
{
+ check_for_signal();
/*
** Match the format of "cc" to allow sh users to
** zic ... 2>&1 | error -t "*" -v
@@ -1074,6 +1076,7 @@ make_links(void)
warning(_("link %s targeting link %s"),
links[i].l_linkname, links[i].l_target);
}
+ check_for_signal();
}
}
@@ -1391,6 +1394,7 @@ main(int argc, char **argv)
for (j = i + 1; j < nzones && zones[j].z_name == NULL; ++j)
continue;
outzone(&zones[i], j - i);
+ check_for_signal();
}
make_links();
if (lcltime != NULL) {
@@ -1486,9 +1490,11 @@ get_rand_u64(void)
static int nwords;
if (!nwords) {
ssize_t s;
- do
+ for (;; check_for_signal()) {
s = getrandom(entropy_buffer, sizeof entropy_buffer, 0);
- while (s < 0 && errno == EINTR);
+ if (! (s < 0 && errno == EINTR))
+ break;
+ }
nwords = s < 0 ? -1 : s / sizeof *entropy_buffer;
}
@@ -1516,7 +1522,7 @@ get_rand_u64(void)
rmod = INT_MAX < UINT_FAST64_MAX ? 0 : UINT_FAST64_MAX / nrand + 1,
r = 0, rmax = 0;
- do {
+ for (;; check_for_signal()) {
uint_fast64_t rmax1 = rmax;
if (rmod) {
/* Avoid signed integer overflow on theoretical platforms
@@ -1527,7 +1533,9 @@ get_rand_u64(void)
rmax1 = nrand * rmax1 + rand_max;
r = nrand * r + rand();
rmax = rmax < rmax1 ? rmax1 : UINT_FAST64_MAX;
- } while (rmax < UINT_FAST64_MAX);
+ if (UINT_FAST64_MAX <= rmax)
+ break;
+ }
return r;
}
@@ -1574,9 +1582,11 @@ random_dirent(char const **name, char **namealloc)
*name = *namealloc = dst;
}
- do
+ for (;; check_for_signal()) {
r = get_rand_u64();
- while (unfair_min <= r);
+ if (r < unfair_min)
+ break;
+ }
for (i = 0; i < suffixlen; i++) {
dst[dirlen + prefixlen + i] = alphabet[r % alphabetlen];
@@ -1611,7 +1621,7 @@ open_outfile(char const **outname, char **tempname)
if (!*tempname)
random_dirent(outname, tempname);
- while (true) {
+ for (;; check_for_signal()) {
int oflags = O_WRONLY | O_BINARY | O_CREAT | O_EXCL;
int fd = open(*outname, oflags, creat_perms);
int err;
@@ -1725,8 +1735,6 @@ dolink(char const *target, char const *linkname, bool
staysymlink)
char const *outname = linkname;
int targetissym = -2, linknameissym = -2;
- check_for_signal();
-
if (strcmp(target, "-") == 0) {
if (remove(linkname) == 0 || errno == ENOENT || errno == ENOTDIR)
return;
@@ -1739,7 +1747,7 @@ dolink(char const *target, char const *linkname, bool
staysymlink)
}
}
- while (true) {
+ for (;; check_for_signal()) {
if (linkat(AT_FDCWD, target, AT_FDCWD, outname, AT_SYMLINK_FOLLOW)
== 0) {
link_errno = 0;
@@ -1791,7 +1799,7 @@ dolink(char const *target, char const *linkname, bool
staysymlink)
int symlink_errno = -1;
if (contents) {
- while (true) {
+ for (;; check_for_signal()) {
if (symlink(contents, outname) == 0) {
symlink_errno = 0;
break;
@@ -1822,7 +1830,7 @@ dolink(char const *target, char const *linkname, bool
staysymlink)
exit(EXIT_FAILURE);
}
tp = open_outfile(&outname, &tempname);
- while ((c = getc(fp)) != EOF)
+ for (; (c = getc(fp)) != EOF; check_for_signal())
putc(c, tp);
close_file(tp, directory, linkname, tempname);
close_file(fp, directory, target, NULL);
@@ -1946,7 +1954,7 @@ static bool
inputline(FILE *fp, char *buf, ptrdiff_t bufsize)
{
ptrdiff_t linelen = 0, ch;
- while ((ch = getc(fp)) != '\n') {
+ for (; (ch = getc(fp)) != '\n'; check_for_signal()) {
if (ch < 0) {
if (ferror(fp)) {
error(_("input error"));
@@ -2033,6 +2041,7 @@ infile(int fnum, char const *name)
default: unreachable();
}
}
+ check_for_signal();
}
close_file(fp, NULL, filename(fnum), NULL);
if (wantcont)
--
2.51.0
