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hush: fix memory leak. it was actually rather invloved problem.

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Now finally glob/variable expansion is done IN THE RIGHT ORDER!
It opens up a possibility to cleanly fix remaining known bugs.

function                                             old     new   delta
o_save_ptr                                           115     286    +171
o_save_ptr_helper                                      -     115    +115
done_word                                            591     690     +99
o_get_last_ptr                                         -      31     +31
expand_on_ifs                                        125      97     -28
add_string_to_strings                                 28       -     -28
run_list                                            1895    1862     -33
debug_print_strings                                   42       -     -42
add_strings_to_strings                               126       -    -126
expand_variables                                    1550    1394    -156
o_debug_list                                         168       -    -168
expand_strvec_to_strvec                              388      10    -378
------------------------------------------------------------------------------
(add/remove: 2/4 grow/shrink: 2/4 up/down: 416/-959)         Total: -543 bytes
This commit is contained in:
Denis Vlasenko 2008-06-17 05:11:43 +00:00
parent ccce59d562
commit b61e13d247
1 changed files with 175 additions and 138 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

313
shell/hush.c
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@ -104,6 +104,8 @@
#define debug_printf_exec(...) do {} while (0) #define debug_printf_exec(...) do {} while (0)
#define debug_printf_jobs(...) do {} while (0) #define debug_printf_jobs(...) do {} while (0)
#define debug_printf_expand(...) do {} while (0) #define debug_printf_expand(...) do {} while (0)
#define debug_printf_glob(...) do {} while (0)
#define debug_printf_list(...) do {} while (0)
#define debug_printf_clean(...) do {} while (0) #define debug_printf_clean(...) do {} while (0)
#ifndef debug_printf #ifndef debug_printf
@ -120,12 +122,27 @@
#ifndef debug_printf_jobs #ifndef debug_printf_jobs
#define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__) #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_SHELL_JOBS 1 #define DEBUG_JOBS 1
#else
#define DEBUG_JOBS 0
#endif #endif
#ifndef debug_printf_expand #ifndef debug_printf_expand
#define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__) #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_EXPAND 1 #define DEBUG_EXPAND 1
#else
#define DEBUG_EXPAND 0
#endif
#ifndef debug_printf_glob
#define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_GLOB 1
#else
#define DEBUG_GLOB 0
#endif
#ifndef debug_printf_list
#define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
#endif #endif
/* Keep unconditionally on for now */ /* Keep unconditionally on for now */
@ -143,6 +160,17 @@ static const char *indenter(int i)
#define DEBUG_CLEAN 1 #define DEBUG_CLEAN 1
#endif #endif
#if DEBUG_EXPAND
static void debug_print_strings(const char *prefix, char **vv)
{
fprintf(stderr, "%s:\n", prefix);
while (*vv)
fprintf(stderr, " '%s'\n", *vv++);
}
#else
#define debug_print_strings(prefix, vv) ((void)0)
#endif
/* /*
* Leak hunting. Use hush_leaktool.sh for post-processing. * Leak hunting. Use hush_leaktool.sh for post-processing.
@ -309,6 +337,7 @@ typedef struct {
int length; int length;
int maxlen; int maxlen;
smallint o_quote; smallint o_quote;
smallint o_glob;
smallint nonnull; smallint nonnull;
smallint has_empty_slot; smallint has_empty_slot;
} o_string; } o_string;
@ -531,6 +560,18 @@ static int set_local_var(char *str, int flg_export);
static void unset_local_var(const char *name); static void unset_local_var(const char *name);
static int glob_needed(const char *s)
{
while (*s) {
if (*s == '\\')
s++;
if (*s == '*' || *s == '[' || *s == '?')
return 1;
s++;
}
return 0;
}
static char **add_strings_to_strings(int need_xstrdup, char **strings, char **add) static char **add_strings_to_strings(int need_xstrdup, char **strings, char **add)
{ {
int i; int i;
@ -592,17 +633,6 @@ static char **alloc_ptrs(char **argv)
} }
#endif #endif
#ifdef DEBUG_EXPAND
static void debug_print_strings(const char *prefix, char **vv)
{
fprintf(stderr, "%s:\n", prefix);
while (*vv)
fprintf(stderr, " '%s'\n", *vv++);
}
#else
#define debug_print_strings(prefix, vv) ((void)0)
#endif
/* Function prototypes for builtins */ /* Function prototypes for builtins */
static int builtin_cd(char **argv); static int builtin_cd(char **argv);
@ -1260,7 +1290,33 @@ static void o_addQstr(o_string *o, const char *str, int len)
* o_finalize_list() operation post-processes this structure - calculates * o_finalize_list() operation post-processes this structure - calculates
* and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well. * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
*/ */
static int o_save_ptr(o_string *o, int n) #if DEBUG_EXPAND || DEBUG_GLOB
static void debug_print_list(const char *prefix, o_string *o, int n)
{
char **list = (char**)o->data;
int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
int i = 0;
fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
prefix, list, n, string_start, o->length, o->maxlen);
while (i < n) {
fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
o->data + (int)list[i] + string_start,
o->data + (int)list[i] + string_start);
i++;
}
if (n) {
const char *p = o->data + (int)list[n - 1] + string_start;
fprintf(stderr, " total_sz:%d\n", (p + strlen(p) + 1) - o->data);
}
}
#else
#define debug_print_list(prefix, o, n) ((void)0)
#endif
/* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
* in list[n] so that it points past last stored byte so far.
* It returns n+1. */
static int o_save_ptr_helper(o_string *o, int n)
{ {
char **list = (char**)o->data; char **list = (char**)o->data;
int string_start; int string_start;
@ -1270,26 +1326,27 @@ static int o_save_ptr(o_string *o, int n)
string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
string_len = o->length - string_start; string_len = o->length - string_start;
if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */ if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
//bb_error_msg("list[%d]=%d string_start=%d (growing)", n, string_len, string_start); debug_printf_list("list[%d]=%d string_start=%d (growing)", n, string_len, string_start);
/* list[n] points to string_start, make space for 16 more pointers */ /* list[n] points to string_start, make space for 16 more pointers */
o->maxlen += 0x10 * sizeof(list[0]); o->maxlen += 0x10 * sizeof(list[0]);
o->data = xrealloc(o->data, o->maxlen + 1); o->data = xrealloc(o->data, o->maxlen + 1);
list = (char**)o->data; list = (char**)o->data;
memmove(list + n + 0x10, list + n, string_len); memmove(list + n + 0x10, list + n, string_len);
o->length += 0x10 * sizeof(list[0]); o->length += 0x10 * sizeof(list[0]);
} } else
//else bb_error_msg("list[%d]=%d string_start=%d", n, string_len, string_start); debug_printf_list("list[%d]=%d string_start=%d", n, string_len, string_start);
} else { } else {
/* We have empty slot at list[n], reuse without growth */ /* We have empty slot at list[n], reuse without growth */
string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */ string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
string_len = o->length - string_start; string_len = o->length - string_start;
//bb_error_msg("list[%d]=%d string_start=%d (empty slot)", n, string_len, string_start); debug_printf_list("list[%d]=%d string_start=%d (empty slot)", n, string_len, string_start);
o->has_empty_slot = 0; o->has_empty_slot = 0;
} }
list[n] = (char*)string_len; list[n] = (char*)string_len;
return n + 1; return n + 1;
} }
/* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
static int o_get_last_ptr(o_string *o, int n) static int o_get_last_ptr(o_string *o, int n)
{ {
char **list = (char**)o->data; char **list = (char**)o->data;
@ -1298,14 +1355,89 @@ static int o_get_last_ptr(o_string *o, int n)
return ((int)list[n-1]) + string_start; return ((int)list[n-1]) + string_start;
} }
/* Convert every \x to x in-place, return ptr past NUL. */
static char *unbackslash(char *src)
{
char *dst = src;
while (1) {
if (*src == '\\')
src++;
if ((*dst++ = *src++) == '\0')
break;
}
return dst;
}
static int o_glob(o_string *o, int n)
{
glob_t globdata;
int gr;
char *pattern;
debug_printf_glob("start o_glob: n:%d o->data:%p", n, o->data);
if (!o->data)
return o_save_ptr_helper(o, n);
pattern = o->data + o_get_last_ptr(o, n);
debug_printf_glob("glob pattern '%s'", pattern);
if (!glob_needed(pattern)) {
literal:
o->length = unbackslash(pattern) - o->data;
debug_printf_glob("glob pattern '%s' is literal", pattern);
return o_save_ptr_helper(o, n);
}
memset(&globdata, 0, sizeof(globdata));
gr = glob(pattern, 0, NULL, &globdata);
debug_printf_glob("glob('%s'):%d\n", pattern, gr);
if (gr == GLOB_NOSPACE)
bb_error_msg_and_die("out of memory during glob");
if (gr == GLOB_NOMATCH) {
globfree(&globdata);
goto literal;
}
if (gr != 0) { /* GLOB_ABORTED ? */
//TODO: testcase for bad glob pattern behavior
bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
}
if (globdata.gl_pathv && globdata.gl_pathv[0]) {
char **argv = globdata.gl_pathv;
o->length = pattern - o->data; /* "forget" pattern */
while (1) {
o_addstr(o, *argv, strlen(*argv) + 1);
n = o_save_ptr_helper(o, n);
argv++;
if (!*argv)
break;
}
}
globfree(&globdata);
if (DEBUG_GLOB)
debug_print_list("o_glob returning", o, n);
return n;
}
/* o_save_ptr_helper + but glob the string so far remembered
* if o->o_glob == 1 */
static int o_save_ptr(o_string *o, int n)
{
if (o->o_glob)
return o_glob(o, n); /* o_save_ptr_helper is inside */
return o_save_ptr_helper(o, n);
}
/* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
static char **o_finalize_list(o_string *o, int n) static char **o_finalize_list(o_string *o, int n)
{ {
char **list = (char**)o->data; char **list;
int string_start; int string_start;
o_save_ptr(o, n); /* force growth for list[n] if necessary */ n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); if (DEBUG_EXPAND)
list[n] = NULL; debug_print_list("finalized", o, n);
debug_printf_expand("finalized n:%d", n);
list = (char**)o->data;
string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
list[--n] = NULL;
while (n) { while (n) {
n--; n--;
list[n] = o->data + (int)list[n] + string_start; list[n] = o->data + (int)list[n] + string_start;
@ -1313,28 +1445,6 @@ static char **o_finalize_list(o_string *o, int n)
return list; return list;
} }
#ifdef DEBUG_EXPAND
static void o_debug_list(const char *prefix, o_string *o, int n)
{
char **list = (char**)o->data;
int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
int i = 0;
fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
prefix, list, n, string_start, o->length, o->maxlen);
while (i < n) {
fprintf(stderr, " list[%d]=%d '%s'\n", i, (int)list[i],
o->data + (int)list[i] + string_start);
i++;
}
if (n) {
const char *p = o->data + (int)list[n] + string_start;
fprintf(stderr, " total_sz:%d\n", (p + strlen(p) + 1) - o->data);
}
}
#else
#define o_debug_list(prefix, o, n) ((void)0)
#endif
/* /*
* in_str support * in_str support
@ -1782,7 +1892,7 @@ static int checkjobs(struct pipe* fg_pipe)
while ((childpid = waitpid(-1, &status, attributes)) > 0) { while ((childpid = waitpid(-1, &status, attributes)) > 0) {
const int dead = WIFEXITED(status) || WIFSIGNALED(status); const int dead = WIFEXITED(status) || WIFSIGNALED(status);
#ifdef DEBUG_SHELL_JOBS #if DEBUG_JOBS
if (WIFSTOPPED(status)) if (WIFSTOPPED(status))
debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n", debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
childpid, WSTOPSIG(status), WEXITSTATUS(status)); childpid, WSTOPSIG(status), WEXITSTATUS(status));
@ -2502,11 +2612,11 @@ static int expand_on_ifs(o_string *output, int n, const char *str)
if (!*str) /* EOL - do not finalize word */ if (!*str) /* EOL - do not finalize word */
break; break;
o_addchr(output, '\0'); o_addchr(output, '\0');
o_debug_list("expand_on_ifs", output, n); debug_print_list("expand_on_ifs", output, n);
n = o_save_ptr(output, n); n = o_save_ptr(output, n);
str += strspn(str, ifs); /* skip ifs chars */ str += strspn(str, ifs); /* skip ifs chars */
} }
o_debug_list("expand_on_ifs[1]", output, n); debug_print_list("expand_on_ifs[1]", output, n);
return n; return n;
} }
@ -2530,9 +2640,9 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
ored_ch = 0; ored_ch = 0;
debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg); debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
o_debug_list("expand_vars_to_list", output, n); debug_print_list("expand_vars_to_list", output, n);
n = o_save_ptr(output, n); n = o_save_ptr(output, n);
o_debug_list("expand_vars_to_list[0]", output, n); debug_print_list("expand_vars_to_list[0]", output, n);
while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) { while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
#if ENABLE_HUSH_TICK #if ENABLE_HUSH_TICK
@ -2540,7 +2650,7 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
#endif #endif
o_addQstr(output, arg, p - arg); o_addQstr(output, arg, p - arg);
o_debug_list("expand_vars_to_list[1]", output, n); debug_print_list("expand_vars_to_list[1]", output, n);
arg = ++p; arg = ++p;
p = strchr(p, SPECIAL_VAR_SYMBOL); p = strchr(p, SPECIAL_VAR_SYMBOL);
@ -2575,9 +2685,9 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
/* this argv[] is not empty and not last: /* this argv[] is not empty and not last:
* put terminating NUL, start new word */ * put terminating NUL, start new word */
o_addchr(output, '\0'); o_addchr(output, '\0');
o_debug_list("expand_vars_to_list[2]", output, n); debug_print_list("expand_vars_to_list[2]", output, n);
n = o_save_ptr(output, n); n = o_save_ptr(output, n);
o_debug_list("expand_vars_to_list[3]", output, n); debug_print_list("expand_vars_to_list[3]", output, n);
} }
} }
} else } else
@ -2589,7 +2699,7 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
if (++i >= global_argc) if (++i >= global_argc)
break; break;
o_addchr(output, '\0'); o_addchr(output, '\0');
o_debug_list("expand_vars_to_list[4]", output, n); debug_print_list("expand_vars_to_list[4]", output, n);
n = o_save_ptr(output, n); n = o_save_ptr(output, n);
} }
} else { /* quoted $*: add as one word */ } else { /* quoted $*: add as one word */
@ -2647,9 +2757,9 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
} /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */ } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
if (arg[0]) { if (arg[0]) {
o_debug_list("expand_vars_to_list[a]", output, n); debug_print_list("expand_vars_to_list[a]", output, n);
o_addQstr(output, arg, strlen(arg) + 1); o_addQstr(output, arg, strlen(arg) + 1);
o_debug_list("expand_vars_to_list[b]", output, n); debug_print_list("expand_vars_to_list[b]", output, n);
} else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */ } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
&& !(ored_ch & 0x80) /* and all vars were not quoted. */ && !(ored_ch & 0x80) /* and all vars were not quoted. */
) { ) {
@ -2662,106 +2772,33 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
return n; return n;
} }
static char **expand_variables(char **argv, char or_mask) static char **expand_variables(char **argv, int or_mask)
{ {
int n; int n;
char **list; char **list;
char **v; char **v;
o_string output = NULL_O_STRING; o_string output = NULL_O_STRING;
if (or_mask & 0x100)
output.o_glob = 1;
n = 0; n = 0;
v = argv; v = argv;
while (*v) while (*v) {
n = expand_vars_to_list(&output, n, *v++, or_mask); n = expand_vars_to_list(&output, n, *v, (char)or_mask);
o_debug_list("expand_variables", &output, n); v++;
}
debug_print_list("expand_variables", &output, n);
/* output.data (malloced in one block) gets returned in "list" */ /* output.data (malloced in one block) gets returned in "list" */
list = o_finalize_list(&output, n); list = o_finalize_list(&output, n);
debug_print_strings("expand_variables[1]", list);
return list; return list;
} }
/* Remove non-backslashed backslashes and add to "strings" vector.
* XXX broken if the last character is '\\', check that before calling.
*/
static char **add_unq_string_to_strings(char **strings, const char *src)
{
int cnt;
const char *s;
char *v, *dest;
for (cnt = 1, s = src; s && *s; s++) {
if (*s == '\\') s++;
cnt++;
}
v = dest = xmalloc(cnt);
for (s = src; s && *s; s++, dest++) {
if (*s == '\\') s++;
*dest = *s;
}
*dest = '\0';
return add_string_to_strings(strings, v);
}
/* XXX broken if the last character is '\\', check that before calling */
static int glob_needed(const char *s)
{
for (; *s; s++) {
if (*s == '\\')
s++;
if (strchr("*[?", *s))
return 1;
}
return 0;
}
static void xglob(char ***pglob, const char *pattern)
{
if (glob_needed(pattern)) {
glob_t globdata;
int gr;
memset(&globdata, 0, sizeof(globdata));
gr = glob(pattern, 0, NULL, &globdata);
debug_printf("glob returned %d\n", gr);
if (gr == GLOB_NOSPACE)
bb_error_msg_and_die("out of memory during glob");
if (gr == GLOB_NOMATCH) {
globfree(&globdata);
goto literal;
}
if (gr != 0) { /* GLOB_ABORTED ? */
bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
//TODO: testcase for bad glob pattern behavior
}
if (globdata.gl_pathv && globdata.gl_pathv[0])
*pglob = add_strings_to_strings(1, *pglob, globdata.gl_pathv);
globfree(&globdata);
return;
}
literal:
/* quote removal, or more accurately, backslash removal */
*pglob = add_unq_string_to_strings(*pglob, pattern);
debug_print_strings("after xglob", *pglob);
}
//LEAK is here: callers expect result to be free()able, but we
//actually require free_strings(). free() leaks strings.
static char **expand_strvec_to_strvec(char **argv) static char **expand_strvec_to_strvec(char **argv)
{ {
char **exp; return expand_variables(argv, 0x100);
char **res = xzalloc(sizeof(res[0]));
debug_print_strings("expand_strvec_to_strvec: pre expand", argv);
exp = argv = expand_variables(argv, 0);
debug_print_strings("expand_strvec_to_strvec: post expand", argv);
while (*argv) {
xglob(&res, *argv++);
}
free(exp);
debug_print_strings("expand_strvec_to_strvec: res", res);
return res;
} }
/* used for expansion of right hand of assignments */ /* used for expansion of right hand of assignments */