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 --- elf/dl-support.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'elf/dl-support.c') diff --git a/elf/dl-support.c b/elf/dl-support.c index d2aa52d..a9d63ff 100644 --- a/elf/dl-support.c +++ b/elf/dl-support.c @@ -43,6 +43,7 @@ #include #include #include +#include extern char *__progname; char **_dl_argv = &__progname; /* This is checked for some error messages. */ @@ -417,6 +418,8 @@ _dl_non_dynamic_init (void) break; } + call_function_static_weak (_dl_find_object_init); + /* Setup relro on the binary itself. */ if (_dl_main_map.l_relro_size != 0) _dl_protect_relro (&_dl_main_map); -- cgit v1.1