On Tue, Jan 31, 2023 at 08:02:51PM +0000, Al Viro wrote: > On x86 it had been noticed and fixed back in 2014, in 26178ec11ef3 "x86: > mm: consolidate VM_FAULT_RETRY handling". Some of the other architectures > had it dealt with later - e.g. arm in 2017, the fix is 746a272e44141 > "ARM: 8692/1: mm: abort uaccess retries upon fatal signal"; xtensa - > in 2021, the fix is 7b9acbb6aad4f "xtensa: fix uaccess-related livelock > in do_page_fault", etc. > > However, it never had been done on a bunch of architectures - the > current mainline still has that bug on alpha, hexagon, itanic, m68k, > microblaze, nios2, openrisc, parisc, riscv and sparc (both sparc32 and > sparc64). Fixes are trivial, but I've no way to test them for most > of those architectures. FWIW, when I fixed arm and arm64 back in 2017, I did report the issue here with a test case (and again in 2021, with maintainers all explciitly Cc'd): https://lore.kernel.org/lkml/20170822102527.GA14671@leverpostej/ https://lore.kernel.org/linux-arch/20210121123140.GD48431@C02TD0UTHF1T.local/ ... so if anyone has access to those architectures, that test might be useful for verifying the fix. Thanks, Mark.
