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aa449c927

Denys Vlasenko

2018-07-28

SUCCESS Duration: 148s

Subject

hush: make "set -x" output don't redirectable when fd#2 redirected

Binary

No binary (build failed)

Architecture & Compiler Flags

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

—

Build Log

(log yok)

Commit Diff GitHub →

shell/hush.c +84 -45

shell/hush.c+84 -45

@@ -954,9 +954,6 @@ struct globals {
	unsigned func_nest_level; /* solely to prevent "local v" in non-functions */
	# endif
	struct function *top_func;
-	#endif
-	#if ENABLE_HUSH_MODE_X
-	unsigned x_mode_depth;
	#endif
	/* Signal and trap handling */
	#if ENABLE_HUSH_FAST
@@ -993,6 +990,15 @@ struct globals {
	#if ENABLE_HUSH_MEMLEAK
	unsigned long memleak_value;
	#endif
+	#if ENABLE_HUSH_MODE_X
+	unsigned x_mode_depth;
+	/* "set -x" output should not be redirectable with subsequent 2>FILE.
+	* We dup fd#2 to x_mode_fd when "set -x" is executed, and use it
+	* for all subsequent output.
+	*/
+	int x_mode_fd;
+	o_string x_mode_buf;
+	#endif
	#if HUSH_DEBUG
	int debug_indent;
	#endif
@@ -1660,6 +1666,12 @@ static int move_HFILEs_on_redirect(int fd, int avoid_fd)
	}
	fl = fl->next_hfile;
	}
+	#if ENABLE_HUSH_MODE_X
+	if (G.x_mode_fd > 0 && fd == G.x_mode_fd) {
+	G.x_mode_fd = xdup_CLOEXEC_and_close(fd, avoid_fd);
+	return 1; /* "found and moved" */
+	}
+	#endif
	return 0; /* "not in the list" */
	}
	#if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
@@ -2903,6 +2915,11 @@ static void o_addstr(o_string o, const char str)
	o_addblock(o, str, strlen(str));
	}

+	static void o_addstr_with_NUL(o_string o, const char str)
+	{
+	o_addblock(o, str, strlen(str) + 1);
+	}
+
	#if !BB_MMU
	static void nommu_addchr(o_string *o, int ch)
	{
@@ -2913,10 +2930,36 @@ static void nommu_addchr(o_string *o, int ch)
	# define nommu_addchr(o, str) ((void)0)
	#endif

-	static void o_addstr_with_NUL(o_string o, const char str)
+	#if ENABLE_HUSH_MODE_X
+	static void x_mode_addchr(int ch)
	{
-	o_addblock(o, str, strlen(str) + 1);
+	o_addchr(&G.x_mode_buf, ch);
	}
+	static void x_mode_addstr(const char *str)
+	{
+	o_addstr(&G.x_mode_buf, str);
+	}
+	static void x_mode_addblock(const char *str, int len)
+	{
+	o_addblock(&G.x_mode_buf, str, len);
+	}
+	static void x_mode_prefix(void)
+	{
+	int n = G.x_mode_depth;
+	do x_mode_addchr('+'); while (--n >= 0);
+	}
+	static void x_mode_flush(void)
+	{
+	int len = G.x_mode_buf.length;
+	if (len <= 0)
+	return;
+	if (G.x_mode_fd > 0) {
+	G.x_mode_buf.data[len] = '\n';
+	full_write(G.x_mode_fd, G.x_mode_buf.data, len + 1);
+	}
+	G.x_mode_buf.length = 0;
+	}
+	#endif

	/*
	* HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
@@ -8030,31 +8073,26 @@ static void execvp_or_die(char **argv)
	}

	#if ENABLE_HUSH_MODE_X
-	static void print_optionally_squoted(FILE fp, const char str)
+	static void x_mode_print_optionally_squoted(const char *str)
	{
	unsigned len;
	const char *cp;

	cp = str;
-	if (str[0] != '{' && str[0] != '(') for (;;) {
-	if (!*cp) {
-	/* string has no special chars */
-	fputs(str, fp);
-	return;
-	}
-	if (*cp == '\\') break;
-	if (*cp == '\'') break;
-	if (*cp == '"') break;
-	if (*cp == '$') break;
-	if (*cp == '!') break;
-	if (cp == '') break;
-	if (*cp == '[') break;
-	if (*cp == ']') break;
-	#if ENABLE_HUSH_TICK
-	if (*cp == '`') break;
-	#endif
-	if (isspace(*cp)) break;
-	cp++;
+
+	/* the set of chars which-cause-string-to-be-squoted mimics bash */
+	/* test a char with: bash -c 'set -x; echo "CH"' */
+	if (str[strcspn(str, "\\\"'`$(){}[]<>;#&\|~*?!^"
+	" " "\001\002\003\004\005\006\007"
+	"\010\011\012\013\014\015\016\017"
+	"\020\021\022\023\024\025\026\027"
+	"\030\031\032\033\034\035\036\037"
+	)
+	] == '\0'
+	) {
+	/* string has no special chars */
+	x_mode_addstr(str);
+	return;
	}

	cp = str;
@@ -8062,13 +8100,16 @@ static void print_optionally_squoted(FILE fp, const char str)
	/* print '....' up to EOL or first squote */
	len = (int)(strchrnul(cp, '\'') - cp);
	if (len != 0) {
-	fprintf(fp, "'%.*s'", len, cp);
+	x_mode_addchr('\'');
+	x_mode_addblock(cp, len);
+	x_mode_addchr('\'');
	cp += len;
	}
	if (*cp == '\0')
	break;
	/* string contains squote(s), print them as \' */
-	fprintf(fp, "\\'");
+	x_mode_addchr('\\');
+	x_mode_addchr('\'');
	cp++;
	}
	}
@@ -8078,19 +8119,19 @@ static void dump_cmd_in_x_mode(char **argv)
	unsigned n;

	/* "+[+++...][ cmd...]\n\0" */
-	n = G.x_mode_depth;
-	do bb_putchar_stderr('+'); while ((int)(--n) >= 0);
+	x_mode_prefix();
	n = 0;
	while (argv[n]) {
-	if (argv[n][0] == '\0')
-	fputs(" ''", stderr);
-	else {
-	bb_putchar_stderr(' ');
-	print_optionally_squoted(stderr, argv[n]);
+	x_mode_addchr(' ');
+	if (argv[n][0] == '\0') {
+	x_mode_addchr('\'');
+	x_mode_addchr('\'');
+	} else {
+	x_mode_print_optionally_squoted(argv[n]);
	}
	n++;
	}
-	bb_putchar_stderr('\n');
+	x_mode_flush();
	}
	}
	#else
@@ -8885,17 +8926,14 @@ static NOINLINE int run_pipe(struct pipe *pi)
	#if ENABLE_HUSH_MODE_X
	if (G_x_mode) {
	char *eq;
-	if (i == 0) {
-	unsigned n = G.x_mode_depth;
-	do
-	bb_putchar_stderr('+');
-	while ((int)(--n) >= 0);
-	}
+	if (i == 0)
+	x_mode_prefix();
+	x_mode_addchr(' ');
	eq = strchrnul(p, '=');
-	fprintf(stderr, " %.*s=", (int)(eq - p), p);
-	if (*eq)
-	print_optionally_squoted(stderr, eq + 1);
-	bb_putchar_stderr('\n');
+	if (*eq) eq++;
+	x_mode_addblock(p, (eq - p));
+	x_mode_print_optionally_squoted(eq);
+	x_mode_flush();
	}
	#endif
	debug_printf_env("set shell var:'%s'->'%s'\n", *argv, p);
@@ -9691,6 +9729,7 @@ static int set_mode(int state, char mode, const char *o_opt)
	break;
	case 'x':
	IF_HUSH_MODE_X(G_x_mode = state;)
+	IF_HUSH_MODE_X(if (G.x_mode_fd <= 0) G.x_mode_fd = dup_CLOEXEC(2, 10);)
	break;
	case 'o':
	if (!o_opt) {