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hush: fix environment and memory leaks, add tests for them

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function                                             old     new   delta
add_malloced_string_to_strings                         -     110    +110
run_list                                            1999    2086     +87
free_strings_and_unsetenv                              -      87     +87
hush_version_str                                       -      18     +18
pseudo_exec_argv                                     139     146      +7
static.version_str                                    17       -     -17
free_pipe                                            237     210     -27
done_word                                            790     642    -148
------------------------------------------------------------------------------
(add/remove: 3/1 grow/shrink: 2/2 up/down: 309/-192)          Total: 117 bytes
This commit is contained in:
Denis Vlasenko 2008-10-09 16:29:44 +00:00
parent 07e05c100f
commit afd7a8d744
6 changed files with 218 additions and 58 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

149
shell/hush.c
View File

@ -54,7 +54,7 @@
* port selected bugfixes from post-0.49 busybox lash - done?
* change { and } from special chars to reserved words
* builtins: return, trap, ulimit
* test magic exec
* test magic exec with redirection only
* check setting of global_argc and global_argv
* follow IFS rules more precisely, including update semantics
* figure out what to do with backslash-newline
@ -73,7 +73,7 @@
#include <fnmatch.h>
#endif
#define HUSH_VER_STR "0.9"
#define HUSH_VER_STR "0.91"
#if !BB_MMU && ENABLE_HUSH_TICK
//#undef ENABLE_HUSH_TICK
@ -525,13 +525,13 @@ static int free_pipe(struct pipe *pi, int indent);
static int setup_redirects(struct command *prog, int squirrel[]);
static int run_list(struct pipe *pi);
#if BB_MMU
#define pseudo_exec_argv(ptrs2free, argv, assignment_cnt, argv_expanded) \
#define pseudo_exec_argv(ptr_ptrs2free, argv, assignment_cnt, argv_expanded) \
pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
#define pseudo_exec(ptrs2free, command, argv_expanded) \
#define pseudo_exec(ptr_ptrs2free, command, argv_expanded) \
pseudo_exec(command, argv_expanded)
#endif
static void pseudo_exec_argv(char **ptrs2free, char **argv, int assignment_cnt, char **argv_expanded) NORETURN;
static void pseudo_exec(char **ptrs2free, struct command *command, char **argv_expanded) NORETURN;
static void pseudo_exec_argv(char ***ptr_ptrs2free, char **argv, int assignment_cnt, char **argv_expanded) NORETURN;
static void pseudo_exec(char ***ptr_ptrs2free, struct command *command, char **argv_expanded) NORETURN;
static int run_pipe(struct pipe *pi);
/* data structure manipulation: */
static int setup_redirect(struct parse_context *ctx, int fd, redir_type style, struct in_str *input);
@ -576,6 +576,9 @@ static int set_local_var(char *str, int flg_export);
static void unset_local_var(const char *name);
static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
static int glob_needed(const char *s)
{
while (*s) {
@ -650,26 +653,44 @@ static char **add_malloced_string_to_strings(char **strings, char *add)
return add_malloced_strings_to_strings(strings, v);
}
static void free_strings(char **strings)
static void free_strings_and_unsetenv(char **strings, int unset)
{
if (strings) {
char **v = strings;
while (*v)
free(*v++);
free(strings);
char **v;
if (!strings)
return;
v = strings;
while (*v) {
if (unset) {
char *copy;
#if !BB_MMU
/* If this is a magic guard pointer, do not free it,
* and stop unsetting */
if (*v == hush_version_str) {
unset = 0;
v++;
continue;
}
#endif
/* *strchrnul(*v, '=') = '\0'; -- BAD
* In case *v was putenv'ed, we can't
* unsetenv(*v) after taking out '=':
* it won't work, env is modified by taking out!
* horror :( */
copy = xstrndup(*v, strchrnul(*v, '=') - *v);
unsetenv(copy);
free(copy);
}
free(*v++);
}
free(strings);
}
#if !BB_MMU
#define EXTRA_PTRS 5 /* 1 for NULL, 1 for args, 3 for paranoid reasons */
static char **alloc_ptrs(char **argv)
static void free_strings(char **strings)
{
char **v = argv;
while (*v)
v++;
return xzalloc((v - argv + EXTRA_PTRS) * sizeof(v[0]));
free_strings_and_unsetenv(strings, 0);
}
#endif
/* Function prototypes for builtins */
@ -1393,34 +1414,36 @@ static void restore_redirects(int squirrel[])
* XXX no exit() here. If you don't exec, use _exit instead.
* The at_exit handlers apparently confuse the calling process,
* in particular stdin handling. Not sure why? -- because of vfork! (vda) */
static void pseudo_exec_argv(char **ptrs2free, char **argv, int assignment_cnt, char **argv_expanded)
static void pseudo_exec_argv(char ***ptr_ptrs2free, char **argv, int assignment_cnt, char **argv_expanded)
{
int i, rcode;
char *p;
const struct built_in_command *x;
for (i = 0; i < assignment_cnt; i++) {
debug_printf_exec("pid %d environment modification: %s\n",
getpid(), argv[i]);
p = expand_string_to_string(argv[i]);
#if !BB_MMU
*ptrs2free++ = p;
#endif
putenv(p);
}
argv += i;
/* If a variable is assigned in a forest, and nobody listens,
* was it ever really set?
*/
if (!argv[0])
if (!argv[assignment_cnt])
_exit(EXIT_SUCCESS);
for (i = 0; i < assignment_cnt; i++) {
debug_printf_exec("pid %d environment modification: %s\n",
getpid(), *argv);
p = expand_string_to_string(*argv);
putenv(p);
#if !BB_MMU
*ptr_ptrs2free = add_malloced_string_to_strings(*ptr_ptrs2free, p);
#endif
argv++;
}
if (argv_expanded) {
argv = argv_expanded;
} else {
argv = expand_strvec_to_strvec(argv);
#if !BB_MMU
*ptrs2free++ = (char*) argv;
/* Inserting magic guard pointer to not unsetenv junk later */
*ptr_ptrs2free = add_malloced_string_to_strings(*ptr_ptrs2free, (char*)hush_version_str);
*ptr_ptrs2free = add_malloced_string_to_strings(*ptr_ptrs2free, (char*)argv);
#endif
}
@ -1466,10 +1489,10 @@ static void pseudo_exec_argv(char **ptrs2free, char **argv, int assignment_cnt,
/* Called after [v]fork() in run_pipe()
*/
static void pseudo_exec(char **ptrs2free, struct command *command, char **argv_expanded)
static void pseudo_exec(char ***ptr_ptrs2free, struct command *command, char **argv_expanded)
{
if (command->argv)
pseudo_exec_argv(ptrs2free, command->argv, command->assignment_cnt, argv_expanded);
pseudo_exec_argv(ptr_ptrs2free, command->argv, command->assignment_cnt, argv_expanded);
if (command->group) {
#if !BB_MMU
@ -1745,6 +1768,7 @@ static int run_pipe(struct pipe *pi)
int nextin;
int pipefds[2]; /* pipefds[0] is for reading */
struct command *command;
char **ptrs2free = NULL;
char **argv_expanded = NULL;
char **argv;
const struct built_in_command *x;
@ -1796,7 +1820,7 @@ static int run_pipe(struct pipe *pi)
for (i = 0; i < command->assignment_cnt; i++) {
p = expand_string_to_string(argv[i]);
putenv(p);
//FIXME: do we leak p?!
ptrs2free = add_malloced_string_to_strings(ptrs2free, p);
}
/* Expand the rest into (possibly) many strings each */
@ -1805,9 +1829,10 @@ static int run_pipe(struct pipe *pi)
for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
if (strcmp(argv_expanded[0], x->cmd) == 0) {
if (x->function == builtin_exec && argv_expanded[1] == NULL) {
debug_printf("magic exec\n");
debug_printf("exec with redirects only\n");
setup_redirects(command, NULL);
return EXIT_SUCCESS;
rcode = EXIT_SUCCESS;
goto clean_up_and_ret1;
}
debug_printf("builtin inline %s\n", argv_expanded[0]);
/* XXX setup_redirects acts on file descriptors, not FILEs.
@ -1817,10 +1842,13 @@ static int run_pipe(struct pipe *pi)
setup_redirects(command, squirrel);
debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv_expanded[1]);
rcode = x->function(argv_expanded) & 0xff;
free(argv_expanded);
USE_FEATURE_SH_STANDALONE(clean_up_and_ret:)
restore_redirects(squirrel);
debug_printf_exec("run_pipe return %d\n", rcode);
clean_up_and_ret1:
free_strings_and_unsetenv(ptrs2free, 1);
free(argv_expanded);
IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
debug_printf_exec("run_pipe return %d\n", rcode);
return rcode;
}
}
@ -1832,11 +1860,7 @@ static int run_pipe(struct pipe *pi)
save_nofork_data(&G.nofork_save);
debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
rcode = run_nofork_applet_prime(&G.nofork_save, a, argv_expanded);
free(argv_expanded);
restore_redirects(squirrel);
debug_printf_exec("run_pipe return %d\n", rcode);
IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
return rcode;
goto clean_up_and_ret;
}
}
#endif
@ -1856,14 +1880,15 @@ static int run_pipe(struct pipe *pi)
for (i = 0; i < pi->num_cmds; i++) {
#if !BB_MMU
char **ptrs2free = NULL;
/* Avoid confusion WHAT is volatile. Pointer is volatile,
* not the stuff it points to. */
typedef char **ppchar_t;
volatile ppchar_t shared_across_vfork;
#endif
command = &(pi->cmds[i]);
if (command->argv) {
debug_printf_exec(": pipe member '%s' '%s'...\n", command->argv[0], command->argv[1]);
#if !BB_MMU
ptrs2free = alloc_ptrs(command->argv);
#endif
} else
debug_printf_exec(": pipe member with no argv\n");
@ -1873,6 +1898,9 @@ static int run_pipe(struct pipe *pi)
if ((i + 1) < pi->num_cmds)
xpipe(pipefds);
#if !BB_MMU
shared_across_vfork = ptrs2free;
#endif
command->pid = BB_MMU ? fork() : vfork();
if (!command->pid) { /* child */
if (ENABLE_HUSH_JOB)
@ -1906,13 +1934,19 @@ static int run_pipe(struct pipe *pi)
set_jobctrl_sighandler(SIG_DFL);
set_misc_sighandler(SIG_DFL);
signal(SIGCHLD, SIG_DFL);
pseudo_exec(ptrs2free, command, argv_expanded); /* does not return */
/* comment how it sets env????
for single_and_fg, it's already set yes? */
pseudo_exec((char ***) &shared_across_vfork, command, argv_expanded);
/* pseudo_exec() does not return */
}
/* parent */
#if !BB_MMU
ptrs2free = shared_across_vfork;
#endif
free(argv_expanded);
argv_expanded = NULL;
#if !BB_MMU
free_strings(ptrs2free);
#endif
free_strings_and_unsetenv(ptrs2free, 1);
ptrs2free = NULL;
if (command->pid < 0) { /* [v]fork failed */
/* Clearly indicate, was it fork or vfork */
bb_perror_msg(BB_MMU ? "fork" : "vfork");
@ -4077,10 +4111,9 @@ static void setup_job_control(void)
int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int hush_main(int argc, char **argv)
{
static const char version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
static const struct variable const_shell_ver = {
.next = NULL,
.varstr = (char*)version_str,
.varstr = (char*)hush_version_str,
.max_len = 1, /* 0 can provoke free(name) */
.flg_export = 1,
.flg_read_only = 1,
@ -4114,7 +4147,7 @@ int hush_main(int argc, char **argv)
}
e++;
}
putenv((char *)version_str); /* reinstate HUSH_VERSION */
putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
#if ENABLE_FEATURE_EDITING
G.line_input_state = new_line_input_t(FOR_SHELL);
@ -4338,10 +4371,10 @@ static int builtin_exec(char **argv)
return EXIT_SUCCESS; /* bash does this */
{
#if !BB_MMU
char **ptrs2free = alloc_ptrs(argv);
char **ptrs2free = NULL;
#endif
// FIXME: if exec fails, bash does NOT exit! We do...
pseudo_exec_argv(ptrs2free, argv + 1, 0, NULL);
pseudo_exec_argv(&ptrs2free, argv + 1, 0, NULL);
/* never returns */
}
}

1
shell/hush_test/hush-vars/var_leaks.right Normal file
View File

@ -0,0 +1 @@
OK

14
shell/hush_test/hush-vars/var_leaks.tests Executable file
View File

@ -0,0 +1,14 @@
# external program
a=b /bin/true
env | grep ^a=
# builtin
a=b true
env | grep ^a=
# exec with redirection only
# in bash, this leaks!
a=b exec 1>&1
env | grep ^a=
echo OK

47
shell/hush_test/hush-z_slow/leak_var.tests
View File

@ -42,6 +42,53 @@ while test $i != X; do
done
end=`ps -o pid,vsz | grep "^ *$pid "`
# Warm up again (I do need it on my machine)
beg=`ps -o pid,vsz | grep "^ *$pid "`
i=1
while test $i != X; do
unset t
t=111111111111111111111111111111111111111111111111111111111111111111111111
export t
unset t
t=111111111111111111111111111111111111111111111111111111111111111111111111
export t
unset t
t=111111111111111111111111111111111111111111111111111111111111111111111111
export t
unset t
t=111111111111111111111111111111111111111111111111111111111111111111111111
export t
unset t
t=111111111111111111111111111111111111111111111111111111111111111111111111
export t
i=1$i
if test $i = 1111111111111111111111111111111111111111111111; then i=2; fi
if test $i = 1111111111111111111111111111111111111111111112; then i=3; fi
if test $i = 1111111111111111111111111111111111111111111113; then i=4; fi
if test $i = 1111111111111111111111111111111111111111111114; then i=5; fi
if test $i = 1111111111111111111111111111111111111111111115; then i=6; fi
if test $i = 1111111111111111111111111111111111111111111116; then i=7; fi
if test $i = 1111111111111111111111111111111111111111111117; then i=8; fi
if test $i = 1111111111111111111111111111111111111111111118; then i=9; fi
if test $i = 1111111111111111111111111111111111111111111119; then i=a; fi
if test $i = 111111111111111111111111111111111111111111111a; then i=b; fi
if test $i = 111111111111111111111111111111111111111111111b; then i=c; fi
if test $i = 111111111111111111111111111111111111111111111c; then i=d; fi
if test $i = 111111111111111111111111111111111111111111111d; then i=e; fi
if test $i = 111111111111111111111111111111111111111111111e; then i=f; fi
if test $i = 111111111111111111111111111111111111111111111f; then i=g; fi
if test $i = 111111111111111111111111111111111111111111111g; then i=h; fi
if test $i = 111111111111111111111111111111111111111111111h; then i=i; fi
if test $i = 111111111111111111111111111111111111111111111i; then i=j; fi
if test $i = 111111111111111111111111111111111111111111111j; then i=X; fi
done
end=`ps -o pid,vsz | grep "^ *$pid "`
if test "$beg" != "$end"; then
true echo "vsz grows: $beg -> $end"
else
true echo "vsz does not grow"
fi
echo "Measuring memory leak..."
beg=`ps -o pid,vsz | grep "^ *$pid "`
i=1

2
shell/hush_test/hush-z_slow/leak_var2.right Normal file
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@ -0,0 +1,2 @@
Measuring memory leak...
vsz does not grow

63
shell/hush_test/hush-z_slow/leak_var2.tests Executable file
View File

@ -0,0 +1,63 @@
pid=$$
t=1
export t
# Warm up
beg=`ps -o pid,vsz | grep "^ *$pid "`
i=1
while test $i != X; do
t=111111111111111111111111111111111111111111111111111111111111111111111110$i
t=111111111111111111111111111111111111111111111111111111111111111111111111$i true
t=111111111111111111111111111111111111111111111111111111111111111111111112$i /bin/true
t=111111111111111111111111111111111111111111111111111111111111111111111113$i exec 1>&1
i=1$i
if test $i = 1111111111111111111111111111111111111111111111; then i=2; fi
if test $i = 1111111111111111111111111111111111111111111112; then i=3; fi
if test $i = 1111111111111111111111111111111111111111111113; then i=4; fi
if test $i = 1111111111111111111111111111111111111111111114; then i=X; fi
done
end=`ps -o pid,vsz | grep "^ *$pid "`
# Warm up again (I do need it on my machine)
beg=`ps -o pid,vsz | grep "^ *$pid "`
i=1
while test $i != X; do
t=111111111111111111111111111111111111111111111111111111111111111111111110$i
t=111111111111111111111111111111111111111111111111111111111111111111111111$i true
t=111111111111111111111111111111111111111111111111111111111111111111111112$i /bin/true
t=111111111111111111111111111111111111111111111111111111111111111111111113$i exec 1>&1
i=1$i
if test $i = 1111111111111111111111111111111111111111111111; then i=2; fi
if test $i = 1111111111111111111111111111111111111111111112; then i=3; fi
if test $i = 1111111111111111111111111111111111111111111113; then i=4; fi
if test $i = 1111111111111111111111111111111111111111111114; then i=X; fi
done
end=`ps -o pid,vsz | grep "^ *$pid "`
if test "$beg" != "$end"; then
true echo "vsz grows: $beg -> $end"
else
true echo "vsz does not grow"
fi
echo "Measuring memory leak..."
beg=`ps -o pid,vsz | grep "^ *$pid "`
i=1
while test $i != X; do
t=111111111111111111111111111111111111111111111111111111111111111111111110$i
t=111111111111111111111111111111111111111111111111111111111111111111111111$i true
t=111111111111111111111111111111111111111111111111111111111111111111111112$i /bin/true
t=111111111111111111111111111111111111111111111111111111111111111111111113$i exec 1>&1
i=1$i
if test $i = 1111111111111111111111111111111111111111111111; then i=2; fi
if test $i = 1111111111111111111111111111111111111111111112; then i=3; fi
if test $i = 1111111111111111111111111111111111111111111113; then i=4; fi
if test $i = 1111111111111111111111111111111111111111111114; then i=X; fi
done
end=`ps -o pid,vsz | grep "^ *$pid "`
if test "$beg" != "$end"; then
echo "vsz grows: $beg -> $end"
else
echo "vsz does not grow"
fi