avoid malloc of ctor queue for programs with no external deps

together with the previous two commits, this completes restoration of
the property that dynamic-linked apps with no external deps and no tls
have no failure paths before entry.
This commit is contained in:
Rich Felker 2019-03-03 13:24:23 -05:00
parent f034f145bd
commit 43e7efb465
1 changed files with 9 additions and 2 deletions

View File

@ -30,6 +30,7 @@ static void error(const char *, ...);
#define ALIGN(x,y) ((x)+(y)-1 & -(y))
#define container_of(p,t,m) ((t*)((char *)(p)-offsetof(t,m)))
#define countof(a) ((sizeof (a))/(sizeof (a)[0]))
struct debug {
int ver;
@ -135,6 +136,7 @@ static pthread_mutex_t init_fini_lock;
static pthread_cond_t ctor_cond;
static struct dso *builtin_deps[2];
static struct dso *const no_deps[1];
static struct dso *builtin_ctor_queue[4];
static struct dso **main_ctor_queue;
static struct fdpic_loadmap *app_loadmap;
static struct fdpic_dummy_loadmap app_dummy_loadmap;
@ -1405,7 +1407,10 @@ static struct dso **queue_ctors(struct dso *dso)
p->mark = 0;
}
cnt++; /* termination slot */
stack = queue = calloc(cnt, sizeof *queue);
if (dso==head && cnt <= countof(builtin_ctor_queue))
queue = builtin_ctor_queue;
else
queue = calloc(cnt, sizeof *queue);
if (!queue) {
error("Error allocating constructor queue: %m\n");
@ -1416,6 +1421,7 @@ static struct dso **queue_ctors(struct dso *dso)
/* Opposite ends of the allocated buffer serve as an output queue
* and a working stack. Setup initial stack with just the argument
* dso and initial queue empty... */
stack = queue;
qpos = 0;
spos = cnt;
stack[--spos] = dso;
@ -1487,7 +1493,8 @@ static void do_init_fini(struct dso **queue)
void __libc_start_init(void)
{
do_init_fini(main_ctor_queue);
if (!__malloc_replaced) free(main_ctor_queue);
if (!__malloc_replaced && main_ctor_queue != builtin_ctor_queue)
free(main_ctor_queue);
main_ctor_queue = 0;
}