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]> --- 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); -- 1.5.3.8 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
