From 5d28a8962dcb6ec056b81d730e3c6fb57185a210 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Tue, 28 Dec 2021 22:52:56 +0100 Subject: elf: Add _dl_find_object function It can be used to speed up the libgcc unwinder, and the internal _dl_find_dso_for_object function (which is used for caller identification in dlopen and related functions, and in dladdr). _dl_find_object is in the internal namespace due to bug 28503. If libgcc switches to _dl_find_object, this namespace issue will be fixed. It is located in libc for two reasons: it is necessary to forward the call to the static libc after static dlopen, and there is a link ordering issue with -static-libgcc and libgcc_eh.a because libc.so is not a linker script that includes ld.so in the glibc build tree (so that GCC's internal -lc after libgcc_eh.a does not pick up ld.so). It is necessary to do the i386 customization in the sysdeps/x86/bits/dl_find_object.h header shared with x86-64 because otherwise, multilib installations are broken. The implementation uses software transactional memory, as suggested by Torvald Riegel. Two copies of the supporting data structures are used, also achieving full async-signal-safety. Reviewed-by: Adhemerval Zanella --- include/link.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/link.h') diff --git a/include/link.h b/include/link.h index 6a9f788d2b..b49be89b03 100644 --- a/include/link.h +++ b/include/link.h @@ -211,6 +211,9 @@ struct link_map freed, ie. not allocated with the dummy malloc in ld.so. */ unsigned int l_ld_readonly:1; /* Nonzero if dynamic section is readonly. */ + unsigned int l_find_object_processed:1; /* Zero if _dl_find_object_update + needs to process this + lt_library map. */ /* NODELETE status of the map. Only valid for maps of type lt_loaded. Lazy binding sets l_nodelete_active directly, -- cgit 1.4.1