hush: fix a bug where we don't properly handle f() { a=A; b=B; }; a= f
function old new delta unset_local_var 20 274 +254 leave_var_nest_level - 98 +98 set_vars_and_save_old 128 164 +36 enter_var_nest_level - 32 +32 builtin_local 46 50 +4 pseudo_exec_argv 554 544 -10 redirect_and_varexp_helper 77 64 -13 run_pipe 1890 1641 -249 unset_local_var_len 267 - -267 ------------------------------------------------------------------------------ (add/remove: 2/1 grow/shrink: 3/3 up/down: 424/-539) Total: -115 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
parent
332e4115c9
commit
d358b0b65d
153
shell/hush.c
153
shell/hush.c
@ -475,7 +475,6 @@ static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
|
||||
*/
|
||||
#if !BB_MMU
|
||||
typedef struct nommu_save_t {
|
||||
char **new_env;
|
||||
struct variable *old_vars;
|
||||
char **argv;
|
||||
char **argv_from_re_execing;
|
||||
@ -2176,10 +2175,16 @@ static int set_local_var(char *str, unsigned flags)
|
||||
*eq_sign = '=';
|
||||
}
|
||||
if (cur->var_nest_level < local_lvl) {
|
||||
/* New variable is declared as local,
|
||||
/* New variable is local ("local VAR=VAL" or
|
||||
* "VAR=VAL cmd")
|
||||
* and existing one is global, or local
|
||||
* from enclosing function.
|
||||
* Remove and save old one: */
|
||||
* on a lower level that new one.
|
||||
* Remove and save old one:
|
||||
*/
|
||||
debug_printf_env("shadowing %s'%s'/%u by '%s'/%u\n",
|
||||
cur->flg_export ? "exported " : "",
|
||||
cur->varstr, cur->var_nest_level, str, local_lvl
|
||||
);
|
||||
*cur_pp = cur->next;
|
||||
cur->next = *G.shadowed_vars_pp;
|
||||
*G.shadowed_vars_pp = cur;
|
||||
@ -2197,6 +2202,7 @@ static int set_local_var(char *str, unsigned flags)
|
||||
}
|
||||
|
||||
if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
|
||||
debug_printf_env("assignement '%s' does not change anything\n", str);
|
||||
free_and_exp:
|
||||
free(str);
|
||||
goto exp;
|
||||
@ -2204,6 +2210,7 @@ static int set_local_var(char *str, unsigned flags)
|
||||
if (cur->max_len != 0) {
|
||||
if (cur->max_len >= strlen(str)) {
|
||||
/* This one is from startup env, reuse space */
|
||||
debug_printf_env("reusing startup env for '%s'\n", str);
|
||||
strcpy(cur->varstr, str);
|
||||
goto free_and_exp;
|
||||
}
|
||||
@ -2221,7 +2228,7 @@ static int set_local_var(char *str, unsigned flags)
|
||||
goto set_str_and_exp;
|
||||
}
|
||||
|
||||
/* Not found - create new variable struct */
|
||||
/* Not found or shadowed - create new variable struct */
|
||||
cur = xzalloc(sizeof(*cur));
|
||||
cur->var_nest_level = local_lvl;
|
||||
cur->next = *cur_pp;
|
||||
@ -2250,7 +2257,7 @@ static int set_local_var(char *str, unsigned flags)
|
||||
/* unsetenv was already done */
|
||||
} else {
|
||||
int i;
|
||||
debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
|
||||
debug_printf_env("%s: putenv '%s'/%u\n", __func__, cur->varstr, cur->var_nest_level);
|
||||
i = putenv(cur->varstr);
|
||||
/* only now we can free old exported malloced string */
|
||||
free(free_me);
|
||||
@ -2313,21 +2320,6 @@ static int unset_local_var(const char *name)
|
||||
}
|
||||
#endif
|
||||
|
||||
static void unset_vars(char **strings)
|
||||
{
|
||||
char **v;
|
||||
|
||||
if (!strings)
|
||||
return;
|
||||
v = strings;
|
||||
while (*v) {
|
||||
const char *eq = strchrnul(*v, '=');
|
||||
unset_local_var_len(*v, (int)(eq - *v));
|
||||
v++;
|
||||
}
|
||||
free(strings);
|
||||
}
|
||||
|
||||
#if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ || ENABLE_HUSH_GETOPTS
|
||||
static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
|
||||
{
|
||||
@ -2349,15 +2341,20 @@ static void add_vars(struct variable *var)
|
||||
var->next = G.top_var;
|
||||
G.top_var = var;
|
||||
if (var->flg_export) {
|
||||
debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
|
||||
debug_printf_env("%s: restoring exported '%s'/%u\n", __func__, var->varstr, var->var_nest_level);
|
||||
putenv(var->varstr);
|
||||
} else {
|
||||
debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
|
||||
debug_printf_env("%s: restoring variable '%s'/%u\n", __func__, var->varstr, var->var_nest_level);
|
||||
}
|
||||
var = next;
|
||||
}
|
||||
}
|
||||
|
||||
/* We put strings[i] into variable table and possibly putenv them.
|
||||
* If variable is read only, we can free the strings[i]
|
||||
* which attempts to overwrite it.
|
||||
* The strings[] vector itself is freed.
|
||||
*/
|
||||
static struct variable *set_vars_and_save_old(char **strings)
|
||||
{
|
||||
char **s;
|
||||
@ -2365,6 +2362,7 @@ static struct variable *set_vars_and_save_old(char **strings)
|
||||
|
||||
if (!strings)
|
||||
return old;
|
||||
|
||||
s = strings;
|
||||
while (*s) {
|
||||
struct variable *var_p;
|
||||
@ -2398,11 +2396,15 @@ static struct variable *set_vars_and_save_old(char **strings)
|
||||
var_p->next = old;
|
||||
old = var_p;
|
||||
}
|
||||
set_local_var(*s, SETFLAG_EXPORT);
|
||||
//bb_error_msg("G.var_nest_level:%d", G.var_nest_level);
|
||||
set_local_var(*s, (G.var_nest_level << SETFLAG_VARLVL_SHIFT) | SETFLAG_EXPORT);
|
||||
} else if (HUSH_DEBUG) {
|
||||
bb_error_msg_and_die("BUG in varexp4");
|
||||
}
|
||||
s++;
|
||||
next: ;
|
||||
}
|
||||
free(strings);
|
||||
return old;
|
||||
}
|
||||
|
||||
@ -6339,7 +6341,7 @@ static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
|
||||
#endif
|
||||
|
||||
/* Used for expansion of right hand of assignments,
|
||||
* $((...)), heredocs, variable espansion parts.
|
||||
* $((...)), heredocs, variable expansion parts.
|
||||
*
|
||||
* NB: should NOT do globbing!
|
||||
* "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
|
||||
@ -7385,6 +7387,7 @@ static void exec_function(char ***to_free,
|
||||
static void enter_var_nest_level(void)
|
||||
{
|
||||
G.var_nest_level++;
|
||||
debug_printf_env("var_nest_level++ %u\n", G.var_nest_level);
|
||||
|
||||
/* Try: f() { echo -n .; f; }; f
|
||||
* struct variable::var_nest_level is uint16_t,
|
||||
@ -7408,17 +7411,22 @@ static void leave_var_nest_level(void)
|
||||
continue;
|
||||
}
|
||||
/* Unexport */
|
||||
if (cur->flg_export)
|
||||
if (cur->flg_export) {
|
||||
debug_printf_env("unexporting nested '%s'/%u\n", cur->varstr, cur->var_nest_level);
|
||||
bb_unsetenv(cur->varstr);
|
||||
}
|
||||
/* Remove from global list */
|
||||
*cur_pp = cur->next;
|
||||
/* Free */
|
||||
if (!cur->max_len)
|
||||
if (!cur->max_len) {
|
||||
debug_printf_env("freeing nested '%s'/%u\n", cur->varstr, cur->var_nest_level);
|
||||
free(cur->varstr);
|
||||
}
|
||||
free(cur);
|
||||
}
|
||||
|
||||
G.var_nest_level--;
|
||||
debug_printf_env("var_nest_level-- %u\n", G.var_nest_level);
|
||||
if (HUSH_DEBUG && (int)G.var_nest_level < 0)
|
||||
bb_error_msg_and_die("BUG: nesting underflow");
|
||||
}
|
||||
@ -7431,11 +7439,12 @@ static int run_function(const struct function *funcp, char **argv)
|
||||
|
||||
save_and_replace_G_args(&sv, argv);
|
||||
|
||||
/* "we are in function, ok to use return" */
|
||||
/* "We are in function, ok to use return" */
|
||||
sv_flg = G_flag_return_in_progress;
|
||||
G_flag_return_in_progress = -1;
|
||||
|
||||
enter_var_nest_level();
|
||||
/* Make "local" variables properly shadow previous ones */
|
||||
IF_HUSH_LOCAL(enter_var_nest_level();)
|
||||
IF_HUSH_LOCAL(G.func_nest_level++;)
|
||||
|
||||
/* On MMU, funcp->body is always non-NULL */
|
||||
@ -7451,7 +7460,7 @@ static int run_function(const struct function *funcp, char **argv)
|
||||
}
|
||||
|
||||
IF_HUSH_LOCAL(G.func_nest_level--;)
|
||||
leave_var_nest_level();
|
||||
IF_HUSH_LOCAL(leave_var_nest_level();)
|
||||
|
||||
G_flag_return_in_progress = sv_flg;
|
||||
|
||||
@ -7608,11 +7617,9 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
|
||||
|
||||
#if BB_MMU
|
||||
set_vars_and_save_old(new_env);
|
||||
free(new_env); /* optional */
|
||||
/* we can also destroy set_vars_and_save_old's return value,
|
||||
/* we can destroy set_vars_and_save_old's return value,
|
||||
* to save memory */
|
||||
#else
|
||||
nommu_save->new_env = new_env;
|
||||
nommu_save->old_vars = set_vars_and_save_old(new_env);
|
||||
#endif
|
||||
|
||||
@ -8174,10 +8181,10 @@ static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
|
||||
* subshell: ( list ) [&]
|
||||
*/
|
||||
#if !ENABLE_HUSH_MODE_X
|
||||
#define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
|
||||
redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
|
||||
#define redirect_and_varexp_helper(old_vars_p, command, squirrel, argv_expanded) \
|
||||
redirect_and_varexp_helper(old_vars_p, command, squirrel)
|
||||
#endif
|
||||
static int redirect_and_varexp_helper(char ***new_env_p,
|
||||
static int redirect_and_varexp_helper(
|
||||
struct variable **old_vars_p,
|
||||
struct command *command,
|
||||
struct squirrel **sqp,
|
||||
@ -8190,11 +8197,10 @@ static int redirect_and_varexp_helper(char ***new_env_p,
|
||||
int rcode = setup_redirects(command, sqp);
|
||||
if (rcode == 0) {
|
||||
char **new_env = expand_assignments(command->argv, command->assignment_cnt);
|
||||
*new_env_p = new_env;
|
||||
dump_cmd_in_x_mode(new_env);
|
||||
dump_cmd_in_x_mode(argv_expanded);
|
||||
if (old_vars_p)
|
||||
*old_vars_p = set_vars_and_save_old(new_env);
|
||||
/* this takes ownership of new_env[i] elements, and frees new_env: */
|
||||
*old_vars_p = set_vars_and_save_old(new_env);
|
||||
}
|
||||
return rcode;
|
||||
}
|
||||
@ -8284,13 +8290,9 @@ static NOINLINE int run_pipe(struct pipe *pi)
|
||||
argv = command->argv ? command->argv : (char **) &null_ptr;
|
||||
{
|
||||
const struct built_in_command *x;
|
||||
#if ENABLE_HUSH_FUNCTIONS
|
||||
const struct function *funcp;
|
||||
#else
|
||||
enum { funcp = 0 };
|
||||
#endif
|
||||
char **new_env = NULL;
|
||||
struct variable *old_vars = NULL;
|
||||
IF_HUSH_FUNCTIONS(const struct function *funcp;)
|
||||
IF_NOT_HUSH_FUNCTIONS(enum { funcp = 0 };)
|
||||
struct variable *old_vars;
|
||||
|
||||
#if ENABLE_HUSH_LINENO_VAR
|
||||
if (G.lineno_var)
|
||||
@ -8303,28 +8305,6 @@ static NOINLINE int run_pipe(struct pipe *pi)
|
||||
* Try "a=t >file"
|
||||
*/
|
||||
G.expand_exitcode = 0;
|
||||
#if 0 /* A few cases in testsuite fail with this code. FIXME */
|
||||
rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
|
||||
/* Set shell variables */
|
||||
if (new_env) {
|
||||
argv = new_env;
|
||||
while (*argv) {
|
||||
if (set_local_var(*argv, /*flag:*/ 0)) {
|
||||
/* assignment to readonly var / putenv error? */
|
||||
rcode = 1;
|
||||
}
|
||||
argv++;
|
||||
}
|
||||
}
|
||||
/* Redirect error sets $? to 1. Otherwise,
|
||||
* if evaluating assignment value set $?, retain it.
|
||||
* Try "false; q=`exit 2`; echo $?" - should print 2: */
|
||||
if (rcode == 0)
|
||||
rcode = G.expand_exitcode;
|
||||
/* Exit, _skipping_ variable restoring code: */
|
||||
goto clean_up_and_ret0;
|
||||
|
||||
#else /* Older, bigger, but more correct code */
|
||||
|
||||
rcode = setup_redirects(command, &squirrel);
|
||||
restore_redirects(squirrel);
|
||||
@ -8358,7 +8338,6 @@ static NOINLINE int run_pipe(struct pipe *pi)
|
||||
debug_leave();
|
||||
debug_printf_exec("run_pipe: return %d\n", rcode);
|
||||
return rcode;
|
||||
#endif
|
||||
}
|
||||
|
||||
/* Expand the rest into (possibly) many strings each */
|
||||
@ -8372,6 +8351,7 @@ static NOINLINE int run_pipe(struct pipe *pi)
|
||||
}
|
||||
|
||||
/* if someone gives us an empty string: `cmd with empty output` */
|
||||
//TODO: what about: var=EXPR `` >FILE ? will var be set? Will FILE be created?
|
||||
if (!argv_expanded[0]) {
|
||||
free(argv_expanded);
|
||||
debug_leave();
|
||||
@ -8394,7 +8374,14 @@ static NOINLINE int run_pipe(struct pipe *pi)
|
||||
goto clean_up_and_ret1;
|
||||
}
|
||||
}
|
||||
rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
|
||||
|
||||
/* Without bumping var nesting level, this leaks
|
||||
* exported $a:
|
||||
* a=b true; env | grep ^a=
|
||||
*/
|
||||
enter_var_nest_level();
|
||||
rcode = redirect_and_varexp_helper(&old_vars, command, &squirrel, argv_expanded);
|
||||
|
||||
if (rcode == 0) {
|
||||
if (!funcp) {
|
||||
debug_printf_exec(": builtin '%s' '%s'...\n",
|
||||
@ -8405,24 +8392,23 @@ static NOINLINE int run_pipe(struct pipe *pi)
|
||||
}
|
||||
#if ENABLE_HUSH_FUNCTIONS
|
||||
else {
|
||||
# if ENABLE_HUSH_LOCAL
|
||||
struct variable **sv;
|
||||
sv = G.shadowed_vars_pp;
|
||||
struct variable **sv = G.shadowed_vars_pp;
|
||||
/* Make "local" builtins in the called function
|
||||
* stash shadowed variables in old_vars list
|
||||
*/
|
||||
G.shadowed_vars_pp = &old_vars;
|
||||
# endif
|
||||
|
||||
debug_printf_exec(": function '%s' '%s'...\n",
|
||||
funcp->name, argv_expanded[1]);
|
||||
rcode = run_function(funcp, argv_expanded) & 0xff;
|
||||
# if ENABLE_HUSH_LOCAL
|
||||
|
||||
G.shadowed_vars_pp = sv;
|
||||
# endif
|
||||
}
|
||||
#endif
|
||||
}
|
||||
clean_up_and_ret:
|
||||
unset_vars(new_env);
|
||||
leave_var_nest_level();
|
||||
add_vars(old_vars);
|
||||
/* clean_up_and_ret0: */
|
||||
restore_redirects(squirrel);
|
||||
/*
|
||||
* Try "usleep 99999999" + ^C + "echo $?"
|
||||
@ -8453,7 +8439,8 @@ static NOINLINE int run_pipe(struct pipe *pi)
|
||||
if (ENABLE_FEATURE_SH_NOFORK && NUM_APPLETS > 1) {
|
||||
int n = find_applet_by_name(argv_expanded[0]);
|
||||
if (n >= 0 && APPLET_IS_NOFORK(n)) {
|
||||
rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
|
||||
enter_var_nest_level();
|
||||
rcode = redirect_and_varexp_helper(&old_vars, command, &squirrel, argv_expanded);
|
||||
if (rcode == 0) {
|
||||
debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
|
||||
argv_expanded[0], argv_expanded[1]);
|
||||
@ -8487,7 +8474,6 @@ static NOINLINE int run_pipe(struct pipe *pi)
|
||||
struct fd_pair pipefds;
|
||||
#if !BB_MMU
|
||||
volatile nommu_save_t nommu_save;
|
||||
nommu_save.new_env = NULL;
|
||||
nommu_save.old_vars = NULL;
|
||||
nommu_save.argv = NULL;
|
||||
nommu_save.argv_from_re_execing = NULL;
|
||||
@ -8580,7 +8566,6 @@ static NOINLINE int run_pipe(struct pipe *pi)
|
||||
/* Clean up after vforked child */
|
||||
free(nommu_save.argv);
|
||||
free(nommu_save.argv_from_re_execing);
|
||||
unset_vars(nommu_save.new_env);
|
||||
add_vars(nommu_save.old_vars);
|
||||
#endif
|
||||
free(argv_expanded);
|
||||
@ -10066,7 +10051,11 @@ static int FAST_FUNC builtin_local(char **argv)
|
||||
return EXIT_FAILURE; /* bash compat */
|
||||
}
|
||||
argv++;
|
||||
return helper_export_local(argv, G.var_nest_level << SETFLAG_VARLVL_SHIFT);
|
||||
/* Since all builtins run in a nested variable level,
|
||||
* need to use level - 1 here. Or else the variable will be removed at once
|
||||
* after builtin returns.
|
||||
*/
|
||||
return helper_export_local(argv, (G.var_nest_level - 1) << SETFLAG_VARLVL_SHIFT);
|
||||
}
|
||||
#endif
|
||||
|
||||
|
||||
3
shell/hush_test/hush-vars/var_nested1.right
Normal file
3
shell/hush_test/hush-vars/var_nested1.right
Normal file
@ -0,0 +1,3 @@
|
||||
Expected:AB Actual:AB
|
||||
Expected:Ab Actual:Ab
|
||||
Expected:ab Actual:ab
|
||||
16
shell/hush_test/hush-vars/var_nested1.tests
Executable file
16
shell/hush_test/hush-vars/var_nested1.tests
Executable file
@ -0,0 +1,16 @@
|
||||
f() { a=A; b=B; }
|
||||
|
||||
a=a
|
||||
b=b
|
||||
f
|
||||
echo Expected:AB Actual:$a$b
|
||||
|
||||
a=a
|
||||
b=b
|
||||
b= f
|
||||
echo Expected:Ab Actual:$a$b
|
||||
|
||||
a=a
|
||||
b=b
|
||||
a= b= f
|
||||
echo Expected:ab Actual:$a$b
|
||||
1
shell/hush_test/hush-vars/var_nested2.right
Normal file
1
shell/hush_test/hush-vars/var_nested2.right
Normal file
@ -0,0 +1 @@
|
||||
aB
|
||||
2
shell/hush_test/hush-vars/var_nested2.tests
Executable file
2
shell/hush_test/hush-vars/var_nested2.tests
Executable file
@ -0,0 +1,2 @@
|
||||
# the bug was easier to trigger in one-liner form
|
||||
a=a; b=b; f() { a=A; b=B; }; a= f; echo $a$b
|
||||
Loading…
Reference in New Issue
Block a user