diff options
Diffstat (limited to 'elf/dl-tunables.c')
| -rw-r--r-- | elf/dl-tunables.c | 80 |
1 files changed, 31 insertions, 49 deletions
diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c index 644d21d1b0..3d41e8e28e 100644 --- a/elf/dl-tunables.c +++ b/elf/dl-tunables.c @@ -36,31 +36,8 @@ #define TUNABLES_INTERNAL 1 #include "dl-tunables.h" -#include <not-errno.h> - -static char * -tunables_strdup (const char *in) -{ - size_t i = 0; - - while (in[i++] != '\0'); - char *out = __minimal_malloc (i + 1); - - /* For most of the tunables code, we ignore user errors. However, - this is a system error - and running out of memory at program - startup should be reported, so we do. */ - if (out == NULL) - _dl_fatal_printf ("failed to allocate memory to process tunables\n"); - - while (i-- > 0) - out[i] = in[i]; - - return out; -} - static char ** -get_next_env (char **envp, char **name, size_t *namelen, char **val, - char ***prev_envp) +get_next_env (char **envp, char **name, char **val, char ***prev_envp) { while (envp != NULL && *envp != NULL) { @@ -76,7 +53,6 @@ get_next_env (char **envp, char **name, size_t *namelen, char **val, continue; *name = envline; - *namelen = len; *val = &envline[len + 1]; *prev_envp = prev; @@ -134,14 +110,14 @@ do_tunable_update_val (tunable_t *cur, const tunable_val_t *valp, /* Validate range of the input value and initialize the tunable CUR if it looks good. */ static void -tunable_initialize (tunable_t *cur, const char *strval) +tunable_initialize (tunable_t *cur, const char *strval, size_t len) { - tunable_val_t val; + tunable_val_t val = { 0 }; if (cur->type.type_code != TUNABLE_TYPE_STRING) val.numval = (tunable_num_t) _dl_strtoul (strval, NULL); else - val.strval = strval; + val.strval = (struct tunable_str_t) { strval, len }; do_tunable_update_val (cur, &val, NULL, NULL); } @@ -165,29 +141,29 @@ struct tunable_toset_t { tunable_t *t; const char *value; + size_t len; }; enum { tunables_list_size = array_length (tunable_list) }; /* Parse the tunable string VALSTRING and set TUNABLES with the found tunables - and their respective strings. VALSTRING is a duplicated values, where - delimiters ':' are replaced with '\0', so string tunables are null - terminated. + and their respective values. The VALSTRING is parsed in place, with the + tunable start and size recorded in TUNABLES. Return the number of tunables found (including 0 if the string is empty) or -1 if for an ill-formatted definition. */ static int -parse_tunables_string (char *valstring, struct tunable_toset_t *tunables) +parse_tunables_string (const char *valstring, struct tunable_toset_t *tunables) { if (valstring == NULL || *valstring == '\0') return 0; - char *p = valstring; + const char *p = valstring; bool done = false; int ntunables = 0; while (!done) { - char *name = p; + const char *name = p; /* First, find where the name ends. */ while (*p != '=' && *p != ':' && *p != '\0') @@ -209,7 +185,7 @@ parse_tunables_string (char *valstring, struct tunable_toset_t *tunables) /* Skip the '='. */ p++; - char *value = p; + const char *value = p; while (*p != '=' && *p != ':' && *p != '\0') p++; @@ -218,8 +194,6 @@ parse_tunables_string (char *valstring, struct tunable_toset_t *tunables) return -1; else if (*p == '\0') done = true; - else - *p++ = '\0'; /* Add the tunable if it exists. */ for (size_t i = 0; i < tunables_list_size; i++) @@ -228,7 +202,8 @@ parse_tunables_string (char *valstring, struct tunable_toset_t *tunables) if (tunable_is_name (cur->name, name)) { - tunables[ntunables++] = (struct tunable_toset_t) { cur, value }; + tunables[ntunables++] = + (struct tunable_toset_t) { cur, value, p - value }; break; } } @@ -238,7 +213,7 @@ parse_tunables_string (char *valstring, struct tunable_toset_t *tunables) } static void -parse_tunables (char *valstring) +parse_tunables (const char *valstring) { struct tunable_toset_t tunables[tunables_list_size]; int ntunables = parse_tunables_string (valstring, tunables); @@ -250,7 +225,7 @@ parse_tunables (char *valstring) } for (int i = 0; i < ntunables; i++) - tunable_initialize (tunables[i].t, tunables[i].value); + tunable_initialize (tunables[i].t, tunables[i].value, tunables[i].len); } /* Initialize the tunables list from the environment. For now we only use the @@ -261,19 +236,20 @@ __tunables_init (char **envp) { char *envname = NULL; char *envval = NULL; - size_t len = 0; char **prev_envp = envp; /* Ignore tunables for AT_SECURE programs. */ if (__libc_enable_secure) return; - while ((envp = get_next_env (envp, &envname, &len, &envval, - &prev_envp)) != NULL) + while ((envp = get_next_env (envp, &envname, &envval, &prev_envp)) != NULL) { + /* The environment variable is allocated on the stack by the kernel, so + it is safe to keep the references to the suboptions for later parsing + of string tunables. */ if (tunable_is_name ("GLIBC_TUNABLES", envname)) { - parse_tunables (tunables_strdup (envval)); + parse_tunables (envval); continue; } @@ -291,7 +267,11 @@ __tunables_init (char **envp) /* We have a match. Initialize and move on to the next line. */ if (tunable_is_name (name, envname)) { - tunable_initialize (cur, envval); + size_t envvallen = 0; + /* The environment variable is always null-terminated. */ + for (const char *p = envval; *p != '\0'; p++, envvallen++); + + tunable_initialize (cur, envval, envvallen); break; } } @@ -305,7 +285,7 @@ __tunables_print (void) { const tunable_t *cur = &tunable_list[i]; if (cur->type.type_code == TUNABLE_TYPE_STRING - && cur->val.strval == NULL) + && cur->val.strval.str == NULL) _dl_printf ("%s:\n", cur->name); else { @@ -331,7 +311,9 @@ __tunables_print (void) (size_t) cur->type.max); break; case TUNABLE_TYPE_STRING: - _dl_printf ("%s\n", cur->val.strval); + _dl_printf ("%.*s\n", + (int) cur->val.strval.len, + cur->val.strval.str); break; default: __builtin_unreachable (); @@ -364,7 +346,7 @@ __tunable_get_default (tunable_id_t id, void *valp) } case TUNABLE_TYPE_STRING: { - *((const char **)valp) = cur->def.strval; + *((const struct tunable_str_t **)valp) = &cur->def.strval; break; } default: @@ -399,7 +381,7 @@ __tunable_get_val (tunable_id_t id, void *valp, tunable_callback_t callback) } case TUNABLE_TYPE_STRING: { - *((const char **)valp) = cur->val.strval; + *((const struct tunable_str_t **) valp) = &cur->val.strval; break; } default: |