a59f435b5 — BusyBox

Subject

ash: if tcgetattr(stdin) fails, don't mess with tcsetattr ash: size-optimize ulimit's table of limits

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Architecture & Compiler Flags

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

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shell/ash.c +75 -35

shell/ash.c+75 -35

@@ -11575,26 +11575,31 @@ readcmd(int argc, char **argv)
	ifs = defifs;
	#if ENABLE_ASH_READ_NCHARS
	if (n_flag \|\| silent) {
-	tcgetattr(0, &tty);
-	old_tty = tty;
-	if (n_flag) {
-	tty.c_lflag &= ~ICANON;
-	tty.c_cc[VMIN] = nchars;
-	}
-	if (silent) {
-	tty.c_lflag &= ~(ECHO\|ECHOK\|ECHONL);
+	if (tcgetattr(0, &tty) != 0) {
+	/* Not a tty */
+	n_flag = 0;
+	silent = 0;
+	} else {
+	old_tty = tty;
+	if (n_flag) {
+	tty.c_lflag &= ~ICANON;
+	tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
+	}
+	if (silent) {
+	tty.c_lflag &= ~(ECHO \| ECHOK \| ECHONL);
+	}
+	tcsetattr(0, TCSANOW, &tty);
	}
-	tcsetattr(0, TCSANOW, &tty);
	}
	#endif
	#if ENABLE_ASH_READ_TIMEOUT
	if (ts.tv_sec \|\| ts.tv_usec) {
-	// TODO: replace with poll, it is smaller
	FD_ZERO(&set);
	FD_SET(0, &set);

-	i = select(FD_SETSIZE, &set, NULL, NULL, &ts);
-	if (!i) {
+	/* poll-based wait produces bigger code, using select */
+	i = select(1, &set, NULL, NULL, &ts);
+	if (!i) { /* timed out! */
	#if ENABLE_ASH_READ_NCHARS
	if (n_flag)
	tcsetattr(0, TCSANOW, &old_tty);
@@ -11742,48 +11747,81 @@ umaskcmd(int argc, char **argv)
	*/

	struct limits {
-	const char *name;
-	int cmd;
-	int factor; /* multiply by to get rlim_{cur,max} values */
+	uint8_t cmd; /* RLIMIT_xxx fit into it */
+	uint8_t factor_shift; /* shift by to get rlim_{cur,max} values */
	char option;
	};

-	static const struct limits limits[] = {
+	static const struct limits limits_tbl[] = {
	#ifdef RLIMIT_CPU
-	{ "time(seconds)", RLIMIT_CPU, 1, 't' },
+	{ RLIMIT_CPU, 0, 't' },
	#endif
	#ifdef RLIMIT_FSIZE
-	{ "file(blocks)", RLIMIT_FSIZE, 512, 'f' },
+	{ RLIMIT_FSIZE, 9, 'f' },
	#endif
	#ifdef RLIMIT_DATA
-	{ "data(kbytes)", RLIMIT_DATA, 1024, 'd' },
+	{ RLIMIT_DATA, 10, 'd' },
	#endif
	#ifdef RLIMIT_STACK
-	{ "stack(kbytes)", RLIMIT_STACK, 1024, 's' },
+	{ RLIMIT_STACK, 10, 's' },
	#endif
-	#ifdef RLIMIT_CORE
-	{ "coredump(blocks)", RLIMIT_CORE, 512, 'c' },
+	#ifdef RLIMIT_CORE
+	{ RLIMIT_CORE, 9, 'c' },
	#endif
	#ifdef RLIMIT_RSS
-	{ "memory(kbytes)", RLIMIT_RSS, 1024, 'm' },
+	{ RLIMIT_RSS, 10, 'm' },
	#endif
	#ifdef RLIMIT_MEMLOCK
-	{ "locked memory(kbytes)", RLIMIT_MEMLOCK, 1024, 'l' },
+	{ RLIMIT_MEMLOCK, 10, 'l' },
	#endif
	#ifdef RLIMIT_NPROC
-	{ "process", RLIMIT_NPROC, 1, 'p' },
+	{ RLIMIT_NPROC, 0, 'p' },
	#endif
	#ifdef RLIMIT_NOFILE
-	{ "nofiles", RLIMIT_NOFILE, 1, 'n' },
+	{ RLIMIT_NOFILE, 0, 'n' },
	#endif
	#ifdef RLIMIT_AS
-	{ "vmemory(kbytes)", RLIMIT_AS, 1024, 'v' },
+	{ RLIMIT_AS, 10, 'v' },
	#endif
	#ifdef RLIMIT_LOCKS
-	{ "locks", RLIMIT_LOCKS, 1, 'w' },
+	{ RLIMIT_LOCKS, 0, 'w' },
	#endif
-	{ NULL, 0, 0, '\0' }
	};
+	static const char limits_name[] =
+	#ifdef RLIMIT_CPU
+	"time(seconds)" "\0"
+	#endif
+	#ifdef RLIMIT_FSIZE
+	"file(blocks)" "\0"
+	#endif
+	#ifdef RLIMIT_DATA
+	"data(kb)" "\0"
+	#endif
+	#ifdef RLIMIT_STACK
+	"stack(kb)" "\0"
+	#endif
+	#ifdef RLIMIT_CORE
+	"coredump(blocks)" "\0"
+	#endif
+	#ifdef RLIMIT_RSS
+	"memory(kb)" "\0"
+	#endif
+	#ifdef RLIMIT_MEMLOCK
+	"locked memory(kb)" "\0"
+	#endif
+	#ifdef RLIMIT_NPROC
+	"process" "\0"
+	#endif
+	#ifdef RLIMIT_NOFILE
+	"nofiles" "\0"
+	#endif
+	#ifdef RLIMIT_AS
+	"vmemory(kb)" "\0"
+	#endif
+	#ifdef RLIMIT_LOCKS
+	"locks" "\0"
+	#endif
+	;

	enum limtype { SOFT = 0x1, HARD = 0x2 };

@@ -11800,7 +11838,7 @@ printlim(enum limtype how, const struct rlimit *limit,
	if (val == RLIM_INFINITY)
	out1fmt("unlimited\n");
	else {
-	val /= l->factor;
+	val >>= l->factor_shift;
	out1fmt("%lld\n", (long long) val);
	}
	}
@@ -11866,8 +11904,8 @@ ulimitcmd(int argc, char **argv)
	what = optc;
	}

-	for (l = limits; l->option != what; l++)
-	;
+	for (l = limits_tbl; l->option != what; l++)
+	continue;

	set = *argptr ? 1 : 0;
	if (set) {
@@ -11887,13 +11925,15 @@ ulimitcmd(int argc, char **argv)
	}
	if (c)
	ash_msg_and_raise_error("bad number");
-	val *= l->factor;
+	val <<= l->factor_shift;
	}
	}
	if (all) {
-	for (l = limits; l->name; l++) {
+	const char *lname = limits_name;
+	for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
	getrlimit(l->cmd, &limit);
-	out1fmt("%-20s ", l->name);
+	out1fmt("%-20s ", lname);
+	lname += strlen(lname) + 1;
	printlim(how, &limit, l);
	}
	return 0;