On Mon, 8 Jun 2009 12:15:39 +0000 (UTC) Rafal Jaworowski <r...@freebsd.org> mentioned:
> Author: raj > Date: Mon Jun 8 12:15:39 2009 > New Revision: 193712 > URL: http://svn.freebsd.org/changeset/base/193712 > > Log: > Invalidate cache in pmap_remove_all() on ARM. > > When pages are removed from virtual address space by calling > pmap_remove_all() > CPU caches were not invalidated, which led to read corruption when another > page got mapped at this same virtual address at later time (the CPU was > retrieving stale contents). > > Submitted by: Piotr Ziecik > Obtained from: Semihalf > > Modified: > head/sys/arm/arm/pmap.c > > Modified: head/sys/arm/arm/pmap.c > ============================================================================== > --- head/sys/arm/arm/pmap.c Mon Jun 8 12:10:42 2009 (r193711) > +++ head/sys/arm/arm/pmap.c Mon Jun 8 12:15:39 2009 (r193712) > @@ -3124,7 +3124,19 @@ pmap_remove_all(vm_page_t m) > if (flush == FALSE && (pv->pv_pmap == curpm || > pv->pv_pmap == pmap_kernel())) > flush = TRUE; > + > PMAP_LOCK(pv->pv_pmap); > + /* > + * Cached contents were written-back in pmap_remove_write(), > + * but we still have to invalidate the cache entry to make > + * sure stale data are not retrieved when another page will be > + * mapped under this virtual address. > + */ > + if (pmap_is_current(pv->pv_pmap)) { > + cpu_dcache_inv_range(pv->pv_va, PAGE_SIZE); > + cpu_l2cache_inv_range(pv->pv_va, PAGE_SIZE); > + } > + Hi, Rafal! What about calling the pmap_dcache_wb_range function for each mapping in the cycle instead of calling cpu_XXX_inv_range functions directly? I think something like this would do the trick: % pmap_dcache_wb_range(pv->pv_pmap, pv->pv_va, PAGE_SIZE, FALSE, % (pv->pv_flags & PVF_WRITE) == 0) This will also take care of the writeback cache. I don't know if it is really needed, though. -- Stanislav Sedov ST4096-RIPE
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