From 43e7efb46555f13a556d92944ac05c19b8929b60 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sun, 3 Mar 2019 13:24:23 -0500 Subject: [PATCH] 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. --- ldso/dynlink.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/ldso/dynlink.c b/ldso/dynlink.c index 4f090ada..35cacd76 100644 --- a/ldso/dynlink.c +++ b/ldso/dynlink.c @@ -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; } -- 2.25.1