Date: Thu, 01 May 2025 16:46:11 +0000 From: bugzilla-noreply@freebsd.org To: threads@FreeBSD.org Subject: [Bug 286505] dlopen deadlocks when target library contains IFUNC Message-ID: <bug-286505-13406@https.bugs.freebsd.org/bugzilla/>
index | next in thread | raw e-mail
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=286505 Bug ID: 286505 Summary: dlopen deadlocks when target library contains IFUNC Product: Base System Version: Unspecified Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: threads Assignee: threads@FreeBSD.org Reporter: dapeng.gao@cl.cam.ac.uk CC: kib@FreeBSD.org An ifunc resolver enters _rtld_bind, which attempts to acquire _rtld_bind_lock. But since we are in the middle of dlopen, the lock has been acquired already, hence deadlocking. This is similar to bug #286502 but does not involve filter libraries. Tested on AArch64 but should be reproducible on AMD64. pthread required. Commands: cc main.c -lthr -Wl,-rpath=. -o main cc foo.c -shared -o foo.so ./main Setup: $ cat main.c #include <dlfcn.h> int main() { dlopen("foo.so", RTLD_LAZY); } $ cat foo.c #include <stdio.h> static void foo_impl() { } static void *foo_resolver() { puts("foo_resolver()"); return &foo_impl; } void foo() __attribute__((ifunc("foo_resolver"))); void (*foo_ptr)() = &foo; -- You are receiving this mail because: You are the assignee for the bug.home | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-286505-13406>