From 6d2292f2431ec9405b8789c28c81e8e711c15b2d Mon Sep 17 00:00:00 2001 From: Johannes Stoelp Date: Sat, 6 Apr 2024 23:17:02 +0200 Subject: ld.so: add RTLD_LOCAL, RTLD_DEEPBIND notes + example --- src/development/ldso/deepbind/lib.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 src/development/ldso/deepbind/lib.c (limited to 'src/development/ldso/deepbind/lib.c') diff --git a/src/development/ldso/deepbind/lib.c b/src/development/ldso/deepbind/lib.c new file mode 100644 index 0000000..e18a4ce --- /dev/null +++ b/src/development/ldso/deepbind/lib.c @@ -0,0 +1,23 @@ +#define _GNU_SOURCE +#include +#include + +#ifndef NAME +#define NAME "" +#endif + +void test() { + puts(NAME ":test()"); + + // Lookup next symbol from the libraries scope, which will search only in the + // libraries LOCAL scope, starting from the next object after the current one. + (void)dlsym(RTLD_NEXT, "next_lib" NAME); + + // Global lookup from the libraries scope, which will search libraries in the + // GLOBAL scope and the libraries LOCAL scope. The order in which the scopes + // are searched depends on whether the library was loaded (a) with DEEPBIND or + // (b) not. whether this library was loaded with DEEPBIND). In the first case, + // the LOCAL scope is searched first, where in the latter, the GLOBAL scope is + // searched first. + (void)dlsym(RTLD_DEFAULT, "default_lib" NAME); +} -- cgit v1.2.3