On 2021-01-09 01:33:52 [+0100], Thomas Bogendoerfer wrote: > On Sat, Jan 09, 2021 at 12:58:05AM +0100, Thomas Bogendoerfer wrote: > > On Fri, Jan 08, 2021 at 08:20:43PM +0000, Paul Cercueil wrote: > > > Hi Thomas, > > > > > > 5.11 does not boot anymore on Ingenic SoCs, I bisected it to this commit. > > > > > > Any idea what could be happening? > > > > not yet, kernel crash log of a Malta QEMU is below. > > update: > > This dirty hack lets the Malta QEMU boot again: > > diff --git a/mm/highmem.c b/mm/highmem.c > index c3a9ea7875ef..190cdda1149d 100644 > --- a/mm/highmem.c > +++ b/mm/highmem.c > @@ -515,7 +515,7 @@ void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot) > vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); > BUG_ON(!pte_none(*(kmap_pte - idx))); > pteval = pfn_pte(pfn, prot); > - set_pte_at(&init_mm, vaddr, kmap_pte - idx, pteval); > + set_pte(kmap_pte - idx, pteval); > arch_kmap_local_post_map(vaddr, pteval); > current->kmap_ctrl.pteval[kmap_local_idx()] = pteval; > preempt_enable(); > > set_pte_at() tries to update cache and could do an kmap_atomic() there. So the old implementation used set_pte() while the new one uses set_pte_at(). > Not sure, if this is allowed at this point. The problem is the recursion kmap_atomic() -> __update_cache() -> kmap_atomic() and kmap_local_idx_push() runs out if index space before stack space. I'm not sure if the __update_cache() worked for highmem. It has been added for that in commit f4281bba81810 ("MIPS: Handle highmem pages in __update_cache") but it assumes that the address returned by kmap_atomic() is the same or related enough for flush_data_cache_page() to work. > Thomas. > Sebastian _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel