On Tue, 2008-02-05 at 13:43 -0600, Scott Wood wrote: > Currently, update_mmu_cache will crash if given a no-access PTE. There's no > need to synchronize dcache/icache unless it's an exec mapping -- however, > due to the existence of older glibc versions that execute out of a > read-but-no-exec page, readability is tested instead. > > This assumes no exec-only mappings; if such mappings become supported, they > will need to go through the kmap_atomic() version of dcache/icache > synchronization. > > Signed-off-by: Scott Wood <[EMAIL PROTECTED]>
Acked-by: Benjamin Herrenschmidt <[EMAIL PROTECTED]> > --- > This fixes the following bug: > http://ozlabs.org/pipermail/linuxppc-dev/2008-February/051080.html > > arch/powerpc/mm/mem.c | 7 ++++++- > 1 files changed, 6 insertions(+), 1 deletions(-) > > diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c > index e812244..c7d7bd4 100644 > --- a/arch/powerpc/mm/mem.c > +++ b/arch/powerpc/mm/mem.c > @@ -483,7 +483,12 @@ void update_mmu_cache(struct vm_area_struct *vma, > unsigned long address, > */ > _tlbie(address, 0 /* 8xx doesn't care about PID */); > #endif > - if (!PageReserved(page) > + /* The _PAGE_USER test should really be _PAGE_EXEC, but > + * older glibc versions execute some code from no-exec > + * pages, which for now we are supporting. If exec-only > + * pages are ever implemented, this will have to change. > + */ > + if (!PageReserved(page) && (pte_val(pte) & _PAGE_USER) > && !test_bit(PG_arch_1, &page->flags)) { > if (vma->vm_mm == current->active_mm) { > __flush_dcache_icache((void *) address); _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
