On 26/03/2015 19:55, Ingo Molnar wrote: > > * Laurent Dufour <ldufour@xxxxxxxxxxxxxxxxxx> wrote: > >> +{ >> + unsigned long vdso_end, vdso_start; >> + >> + if (!mm->context.vdso_base) >> + return; >> + vdso_start = mm->context.vdso_base; >> + >> +#ifdef CONFIG_PPC64 >> + /* Calling is_32bit_task() implies that we are dealing with the >> + * current process memory. If there is a call path where mm is not >> + * owned by the current task, then we'll have need to store the >> + * vDSO size in the mm->context. >> + */ >> + BUG_ON(current->mm != mm); >> + if (is_32bit_task()) >> + vdso_end = vdso_start + (vdso32_pages << PAGE_SHIFT); >> + else >> + vdso_end = vdso_start + (vdso64_pages << PAGE_SHIFT); >> +#else >> + vdso_end = vdso_start + (vdso32_pages << PAGE_SHIFT); >> +#endif >> + vdso_end += (1<<PAGE_SHIFT); /* data page */ >> + >> + /* Check if the vDSO is in the range of the remapped area */ >> + if ((vdso_start <= old_start && old_start < vdso_end) || >> + (vdso_start < old_end && old_end <= vdso_end) || >> + (old_start <= vdso_start && vdso_start < old_end)) { >> + /* Update vdso_base if the vDSO is entirely moved. */ >> + if (old_start == vdso_start && old_end == vdso_end && >> + (old_end - old_start) == (new_end - new_start)) >> + mm->context.vdso_base = new_start; >> + else >> + mm->context.vdso_base = 0; >> + } >> +} > > Oh my, that really looks awfully complex, as you predicted, and right > in every mremap() call. I do agree, that's awfully complex ;) > I'm fine with your original, imperfect, KISS approach. Sorry about > this detour ... > > Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx> No problem, so let's stay on the v3 version of the patch. Thanks for Reviewed-by statement which, I guess, applied to the v3 too. Should I resend the v3 ? Thanks, Laurent. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>