From: Rich Felker Date: Tue, 21 Mar 2017 12:35:59 +0000 (-0400) Subject: fix dlopen/dlsym regression opening libs already loaded at startup X-Git-Tag: v1.1.17~86 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0c53178ec09478ca5f6ca6b5ad09d50a10c8f19d;p=musl fix dlopen/dlsym regression opening libs already loaded at startup commit 4ff234f6cba96403b5de6d29d48a59fd73252040 erroneously changed the condition for running certain code at dlopen time to check whether the library was already relocated rather than whether it already had its deps[] table filled. this was out of concern over whether the code under the conditional would be idempotent/safe to call on an already-loaded libraries. however, I missed a consideration in the opposite direction: if a library was loaded at program startup rather than dlopen, its deps[] table was not yet allocated/filled, and load_deps needs to be called at dlopen time in order for dlsym to be able to perform dependency-order symbol lookups. in order to avoid wasteful allocation of lazy-binding relocation tables for libraries which were already loaded and relocated at startup, the check for !p->relocated is not deleted entirely, but moved to apply only to allocation of these dables. --- diff --git a/ldso/dynlink.c b/ldso/dynlink.c index 5361b844..d20dbd87 100644 --- a/ldso/dynlink.c +++ b/ldso/dynlink.c @@ -1768,9 +1768,9 @@ void *dlopen(const char *file, int mode) } /* First load handling */ - if (!p->relocated) { + if (!p->deps) { load_deps(p); - if ((mode & RTLD_LAZY)) { + if (!p->relocated && (mode & RTLD_LAZY)) { prepare_lazy(p); if (p->deps) for (i=0; p->deps[i]; i++) if (!p->deps[i]->relocated)