On 05/25, Mike Frysinger wrote: > > On Tue, May 25, 2010 at 06:23, Oleg Nesterov wrote: > > - arch/blackfin/kernel/ptrace.c:is_user_addr_valid() > > needs mmap_sem around find_vma() > > > > The lockless access to mm->context.sram_list doesn't look > > safe to me. > > > > If we add get_task_mm() - this protects us against > > destroy_context() only. What is the tracee's sub-thread > > does sys_sram_alloc() or sys_sram_free() in parallel? > > i dont believe there are any code paths in UP systems where this would > be a practical problem because sram_list is only updated by syscalls > from userspace.
Yes sure, UP && !PREEMPT is safe. > we probably should add proper locking to this > structure though. Agreed. I'll try to make the trivial patch tomorrow. I think we can just use mm->mmap_sem, is_user_addr_valid() needs this lock for find_vma() anyway. Oleg. _______________________________________________ Uclinux-dist-devel mailing list Uclinux-dist-devel@blackfin.uclinux.org https://blackfin.uclinux.org/mailman/listinfo/uclinux-dist-devel
