Uncaught exceptions are not logged on x86_64

[chelmuth]

With this patch

diff --git a/repos/libports/src/test/libc/main.cc b/repos/libports/src/test/libc/main.cc
index 04c35d6..c561de6 100644
--- a/repos/libports/src/test/libc/main.cc
+++ b/repos/libports/src/test/libc/main.cc
@@ -28,6 +28,8 @@ int main(int argc, char **argv)
 {
        printf("--- libC test ---\n");
 
+       struct Fatal { }; throw Fatal();
+
        printf("Does printf work?\n");
        printf("We can find out by printing a floating-point number: %f. How does that work?\n", 1.234
 

I get the expected output on x86_32 for make run/libc KERNEL=linux.

spawn ./core
Genode 16.11-114-gd83ccd3 <local changes>
4095 MiB RAM assigned to init
[init -> test-libc] --- libC test ---
[init -> test-libc] Error: Uncaught exception of type 'main::Fatal'
[init -> test-libc] Warning: abort called - thread: ep
[init] child "test-libc" exited with exit value 1

but only an abort on x86_64.

spawn ./core
Genode 16.11-114-gd83ccd3 <local changes>
17592186044415 MiB RAM assigned to init
[init -> test-libc] --- libC test ---
[init -> test-libc] Warning: abort called - thread: ep
[init] child "test-libc" exited with exit value 1

[chelmuth]

As @cproc found out by testing make run/log, this issue is related to dynamically linked binaries only (at least with 16.11).

[chelmuth]

@ssumpf I have a small ldso puzzle for you. It seems the linker relocation reverts changes already made to a namespace variable in the function Linker::Dynamic::relocate_non_plt(1, 1). The variable in question is __cxxabiv1::__terminate_handler and part of ld.lib.so resp. cxx.lib.a. I'm somewhat lost without any knowledge about this non-plt relocation stuff and hope you may shed some light on it.