The ABI status of ELF hash tables

Posted Aug 19, 2022 21:47 UTC (Fri) by linuxrocks123 (subscriber, #34648)
In reply to: The ABI status of ELF hash tables by fw
Parent article: The ABI status of ELF hash tables

Do you have a source for this? The kernel ABI is considered sacrosanct to the point that obsolete system calls from the early days of Linux are still around. I'd be surprised if they allowed a system call interface change that broke something as important as glibc.

The ABI status of ELF hash tables

Posted Aug 20, 2022 6:40 UTC (Sat) by izbyshev (guest, #107996) [Link]

The GP most likely refers to CONFIG_LEGACY_VSYSCALL_NONE enabled in Debian Buster[1] and some other distros (and even WSL kernels on Windows[2]), which is indeed an ABI-breaking change (e.g. gettimeofday() crashes on older glibc, breaking use cases like running containers with older distros).

But it's important to understand that it's not the upstream kernel that broke the ABI (in the default configuration) in this case. On the contrary, they introduced a new mode to improve security while preserving (most of) ABI compatibility[3].

[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=852620
[2] https://github.com/microsoft/WSL/issues/4694
[3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/...