On Fri, Dec 04, 2020 at 09:58:21PM +0100, Thomas Gleixner wrote: > On Fri, Dec 04 2020 at 20:27, Corentin Labbe wrote: > > On Fri, Dec 04, 2020 at 04:08:27PM +0100, Thomas Gleixner wrote: > >> On Fri, Dec 04 2020 at 14:26, Corentin Labbe wrote: > >> > On Fri, Dec 04, 2020 at 12:34:05AM +0100, Thomas Gleixner wrote: > >> >> The unmap comes from sg_miter_stop() and looking at the previous > >> >> map/unmap cycles there are never nested maps. > >> >> > >> >> [ 996.943030] cryptset-316 0d..4 73943317us : __kmap_local_pfn_prot: kmap_local_pfn: 1 ffefd000 > >> >> > >> >> is the first event which allocates a nested map. > >> >> > >> >> So something goes south either in sg_miter or in the crypto maze. > >> >> > >> >> Enabling CONFIG_DEBUG_KMAP_LOCAL and function tracing might give us more clue. > >> > > >> > Done, http://kernel.montjoie.ovh/130466.log > >> > >> Does not provide more information with the debug enabled. So can you > >> please enable CONFIG_FUNCTION_TRACER and add 'ftrace=function' to the > >> command line? > > > > Done, http://kernel.montjoie.ovh/130490.log > > Aaargh. That overwrites everything while printing out that > warning. > > Can you please replace the debug patch with the one below and try again? > That stops the trace right on the condition. > > Thanks, > > tglx > --- > diff --git a/mm/highmem.c b/mm/highmem.c > index b49364a306b8..8f8862f79d23 100644 > --- a/mm/highmem.c > +++ b/mm/highmem.c > @@ -485,6 +485,7 @@ static inline bool kmap_high_unmap_local(unsigned long vaddr) > { > #ifdef ARCH_NEEDS_KMAP_HIGH_GET > if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) { > + trace_printk("kunmap_high: %lx\n", vaddr); > kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); > return true; > } > @@ -520,6 +521,7 @@ void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot) > preempt_disable(); > idx = arch_kmap_local_map_idx(kmap_local_idx_push(), pfn); > vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); > + trace_printk("kmap_local_pfn: %d %lx\n", idx, (unsigned long) vaddr); > BUG_ON(!pte_none(*(kmap_pte - idx))); > pteval = pfn_pte(pfn, prot); > set_pte_at(&init_mm, vaddr, kmap_pte - idx, pteval); > @@ -545,8 +547,10 @@ void *__kmap_local_page_prot(struct page *page, pgprot_t prot) > > /* Try kmap_high_get() if architecture has it enabled */ > kmap = arch_kmap_local_high_get(page); > - if (kmap) > + if (kmap) { > + trace_printk("kmap_local_high_get: %lx\n", (unsigned long) kmap); > return kmap; > + } > > return __kmap_local_pfn_prot(page_to_pfn(page), prot); > } > @@ -578,7 +582,11 @@ void kunmap_local_indexed(void *vaddr) > > preempt_disable(); > idx = arch_kmap_local_unmap_idx(kmap_local_idx(), addr); > - WARN_ON_ONCE(addr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); > + trace_printk("kunmap_local: %i %lx\n", idx, (unsigned long) vaddr); > + if (addr != __fix_to_virt(FIX_KMAP_BEGIN + idx)) { > + tracing_off(); > + BUG(); > + } > > arch_kmap_local_pre_unmap(addr); > pte_clear(&init_mm, addr, kmap_pte - idx); > Hello, the result could be found at http://kernel.montjoie.ovh/130739.log Thanks
