Ben Wolsieffer 90b263db85 futex: Don't include process MM in futex key on no-MMU ... [ Upstream commit c73801ae4f22b390228ebf471d55668e824198b6 ] On no-MMU, all futexes are treated as private because there is no need to map a virtual address to physical to match the futex across processes. This doesn't quite work though, because private futexes include the current process's mm_struct as part of their key. This makes it impossible for one process to wake up a shared futex being waited on in another process. Fix this bug by excluding the mm_struct from the key. With a single address space, the futex address is already a unique key. Fixes: 784bdf3bb6 ("futex: Assume all mappings are private on !MMU systems") Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Darren Hart <dvhart@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: André Almeida <andrealmeid@igalia.com> Link: https://lore.kernel.org/r/20231019204548.1236437-2-ben.wolsieffer@hefring.com Signed-off-by: Sasha Levin <sashal@kernel.org>		2023-11-20 11:08:13 +01:00
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Makefile	futex: Move to kernel/futex/	2022-12-31 13:14:04 +01:00
core.c	futex: Don't include process MM in futex key on no-MMU	2023-11-20 11:08:13 +01:00