use alt signal stack when present for implementation-internal signals

[musl] / src / ldso / dlerror.c

diff --git a/src/ldso/dlerror.c b/src/ldso/dlerror.c
index 588828e..afe5925 100644 (file)
--- a/src/ldso/dlerror.c
+++ b/src/ldso/dlerror.c
@@ -2,6 +2,14 @@
 #include <stdlib.h>
 #include <stdarg.h>
 #include "pthread_impl.h"
+#include "dynlink.h"
+#include "lock.h"
+#include "fork_impl.h"
+
+#define malloc __libc_malloc
+#define calloc __libc_calloc
+#define realloc __libc_realloc
+#define free __libc_free
 
 char *dlerror()
 {
@@ -15,22 +23,42 @@ char *dlerror()
                return s;
 }
 
+static volatile int freebuf_queue_lock[1];
+static void **freebuf_queue;
+volatile int *const __dlerror_lockptr = freebuf_queue_lock;
+
 void __dl_thread_cleanup(void)
 {
        pthread_t self = __pthread_self();
-       if (self->dlerror_buf != (void *)-1)
-               free(self->dlerror_buf);
+       if (self->dlerror_buf && self->dlerror_buf != (void *)-1) {
+               LOCK(freebuf_queue_lock);
+               void **p = (void **)self->dlerror_buf;
+               *p = freebuf_queue;
+               freebuf_queue = p;
+               UNLOCK(freebuf_queue_lock);
+       }
 }
 
-__attribute__((__visibility__("hidden")))
-void __dl_vseterr(const char *fmt, va_list ap)
+hidden void __dl_vseterr(const char *fmt, va_list ap)
 {
+       LOCK(freebuf_queue_lock);
+       void **q = freebuf_queue;
+       freebuf_queue = 0;
+       UNLOCK(freebuf_queue_lock);
+
+       while (q) {
+               void **p = *q;
+               free(q);
+               q = p;
+       }
+
        va_list ap2;
        va_copy(ap2, ap);
        pthread_t self = __pthread_self();
        if (self->dlerror_buf != (void *)-1)
                free(self->dlerror_buf);
        size_t len = vsnprintf(0, 0, fmt, ap2);
+       if (len < sizeof(void *)) len = sizeof(void *);
        va_end(ap2);
        char *buf = malloc(len+1);
        if (buf) {
@@ -42,11 +70,18 @@ void __dl_vseterr(const char *fmt, va_list ap)
        self->dlerror_flag = 1;
 }
 
-__attribute__((__visibility__("hidden")))
-void __dl_seterr(const char *fmt, ...)
+hidden void __dl_seterr(const char *fmt, ...)
 {
        va_list ap;
        va_start(ap, fmt);
        __dl_vseterr(fmt, ap);
        va_end(ap);
 }
+
+static int stub_invalid_handle(void *h)
+{
+       __dl_seterr("Invalid library handle %p", (void *)h);
+       return 1;
+}
+
+weak_alias(stub_invalid_handle, __dl_invalid_handle);