From b2964eb1d9a6b8ab1250e8a881cf406182da5875 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Wed, 21 Apr 2021 19:49:51 +0200 Subject: dlfcn: Failures after dlmopen should not terminate process [BZ #24772] Commit 9e78f6f6e7134a5f299cc8de77370218f8019237 ("Implement _dl_catch_error, _dl_signal_error in libc.so [BZ #16628]") has the side effect that distinct namespaces, as created by dlmopen, now have separate implementations of the rtld exception mechanism. This means that the call to _dl_catch_error from libdl in a secondary namespace does not actually install an exception handler because the thread-local variable catch_hook in the libc.so copy in the secondary namespace is distinct from that of the base namepace. As a result, a dlsym/dlopen/... failure in a secondary namespace terminates the process with a dynamic linker error because it looks to the exception handler mechanism as if no handler has been installed. This commit restores GLRO (dl_catch_error) and uses it to set the handler in the base namespace. Reviewed-by: Adhemerval Zanella --- elf/dl-error-skeleton.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'elf/dl-error-skeleton.c') diff --git a/elf/dl-error-skeleton.c b/elf/dl-error-skeleton.c index 2fd62777cf..b699936c6e 100644 --- a/elf/dl-error-skeleton.c +++ b/elf/dl-error-skeleton.c @@ -248,4 +248,16 @@ _dl_receive_error (receiver_fct fct, void (*operate) (void *), void *args) catch_hook = old_catch; receiver = old_receiver; } + +/* Forwarder used for initializing GLRO (_dl_catch_error). */ +int +_rtld_catch_error (const char **objname, const char **errstring, + bool *mallocedp, void (*operate) (void *), + void *args) +{ + /* The reference to _dl_catch_error will eventually be relocated to + point to the implementation in libc.so. */ + return _dl_catch_error (objname, errstring, mallocedp, operate, args); +} + #endif /* DL_ERROR_BOOTSTRAP */ -- cgit 1.4.1