From bc033b63bbfeb6c4b4eb0a1d083c650e4a0d2af8 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 5 Aug 2008 16:19:56 +1000 Subject: [PATCH] powerpc/mm: Fix attribute confusion with htab_bolt_mapping() The function htab_bolt_mapping() is used to create permanent mappings in the MMU hash table, for example, in order to create the linear mapping of vmemmap. It's also used by early boot ioremap (before mem_init_done). However, the way ioremap uses it is incorrect as it passes it the protection flags in the "linux PTE" form while htab_bolt_mapping() expects them in the hash table format. This is made more confusing by the fact that some of those flags are actually in the same position in both cases. This fixes it all by making htab_bolt_mapping() take normal linux protection flags instead, and use a little helper to convert them to htab flags. Callers can now use the usual PAGE_* definitions safely. Signed-off-by: Benjamin Herrenschmidt arch/powerpc/include/asm/mmu-hash64.h | 2 - arch/powerpc/mm/hash_utils_64.c | 65 ++++++++++++++++++++-------------- arch/powerpc/mm/init_64.c | 9 +--- 3 files changed, 44 insertions(+), 32 deletions(-) Signed-off-by: Paul Mackerras --- arch/powerpc/include/asm/mmu-hash64.h | 2 +- arch/powerpc/mm/hash_utils_64.c | 63 +++++++++++++++++---------- arch/powerpc/mm/init_64.c | 9 ++-- 3 files changed, 43 insertions(+), 31 deletions(-) diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h index 19c7a94034..c2df53c5ce 100644 --- a/arch/powerpc/include/asm/mmu-hash64.h +++ b/arch/powerpc/include/asm/mmu-hash64.h @@ -278,7 +278,7 @@ extern int hash_huge_page(struct mm_struct *mm, unsigned long access, unsigned long trap); extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend, - unsigned long pstart, unsigned long mode, + unsigned long pstart, unsigned long prot, int psize, int ssize); extern void set_huge_psize(int psize); extern void add_gpage(unsigned long addr, unsigned long page_size, diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index 5ce5a4dcd0..14be408dfc 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -151,39 +151,53 @@ static struct mmu_psize_def mmu_psize_defaults_gp[] = { }, }; +static unsigned long htab_convert_pte_flags(unsigned long pteflags) +{ + unsigned long rflags = pteflags & 0x1fa; + + /* _PAGE_EXEC -> NOEXEC */ + if ((pteflags & _PAGE_EXEC) == 0) + rflags |= HPTE_R_N; + + /* PP bits. PAGE_USER is already PP bit 0x2, so we only + * need to add in 0x1 if it's a read-only user page + */ + if ((pteflags & _PAGE_USER) && !((pteflags & _PAGE_RW) && + (pteflags & _PAGE_DIRTY))) + rflags |= 1; + + /* Always add C */ + return rflags | HPTE_R_C; +} int htab_bolt_mapping(unsigned long vstart, unsigned long vend, - unsigned long pstart, unsigned long mode, + unsigned long pstart, unsigned long prot, int psize, int ssize) { unsigned long vaddr, paddr; unsigned int step, shift; - unsigned long tmp_mode; int ret = 0; shift = mmu_psize_defs[psize].shift; step = 1 << shift; + prot = htab_convert_pte_flags(prot); + + DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n", + vstart, vend, pstart, prot, psize, ssize); + for (vaddr = vstart, paddr = pstart; vaddr < vend; vaddr += step, paddr += step) { unsigned long hash, hpteg; unsigned long vsid = get_kernel_vsid(vaddr, ssize); unsigned long va = hpt_va(vaddr, vsid, ssize); - tmp_mode = mode; - - /* Make non-kernel text non-executable */ - if (!in_kernel_text(vaddr)) - tmp_mode = mode | HPTE_R_N; - hash = hpt_hash(va, shift, ssize); hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP); - DBG("htab_bolt_mapping: calling %p\n", ppc_md.hpte_insert); - BUG_ON(!ppc_md.hpte_insert); - ret = ppc_md.hpte_insert(hpteg, va, paddr, - tmp_mode, HPTE_V_BOLTED, psize, ssize); + ret = ppc_md.hpte_insert(hpteg, va, paddr, prot, + HPTE_V_BOLTED, psize, ssize); if (ret < 0) break; @@ -519,9 +533,9 @@ static unsigned long __init htab_get_table_size(void) #ifdef CONFIG_MEMORY_HOTPLUG void create_section_mapping(unsigned long start, unsigned long end) { - BUG_ON(htab_bolt_mapping(start, end, __pa(start), - _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX, - mmu_linear_psize, mmu_kernel_ssize)); + BUG_ON(htab_bolt_mapping(start, end, __pa(start), + PAGE_KERNEL, mmu_linear_psize, + mmu_kernel_ssize)); } int remove_section_mapping(unsigned long start, unsigned long end) @@ -570,7 +584,7 @@ void __init htab_initialize(void) { unsigned long table; unsigned long pteg_count; - unsigned long mode_rw; + unsigned long prot, tprot; unsigned long base = 0, size = 0, limit; int i; @@ -628,7 +642,7 @@ void __init htab_initialize(void) mtspr(SPRN_SDR1, _SDR1); } - mode_rw = _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX; + prot = PAGE_KERNEL; #ifdef CONFIG_DEBUG_PAGEALLOC linear_map_hash_count = lmb_end_of_DRAM() >> PAGE_SHIFT; @@ -646,8 +660,10 @@ void __init htab_initialize(void) for (i=0; i < lmb.memory.cnt; i++) { base = (unsigned long)__va(lmb.memory.region[i].base); size = lmb.memory.region[i].size; + tprot = prot | (in_kernel_text(base) ? _PAGE_EXEC : 0); - DBG("creating mapping for region: %lx : %lx\n", base, size); + DBG("creating mapping for region: %lx..%lx (prot: %x)\n", + base, size, tprot); #ifdef CONFIG_U3_DART /* Do not map the DART space. Fortunately, it will be aligned @@ -664,21 +680,21 @@ void __init htab_initialize(void) unsigned long dart_table_end = dart_tablebase + 16 * MB; if (base != dart_tablebase) BUG_ON(htab_bolt_mapping(base, dart_tablebase, - __pa(base), mode_rw, + __pa(base), tprot, mmu_linear_psize, mmu_kernel_ssize)); if ((base + size) > dart_table_end) BUG_ON(htab_bolt_mapping(dart_tablebase+16*MB, base + size, __pa(dart_table_end), - mode_rw, + tprot, mmu_linear_psize, mmu_kernel_ssize)); continue; } #endif /* CONFIG_U3_DART */ BUG_ON(htab_bolt_mapping(base, base + size, __pa(base), - mode_rw, mmu_linear_psize, mmu_kernel_ssize)); + tprot, mmu_linear_psize, mmu_kernel_ssize)); } /* @@ -696,7 +712,7 @@ void __init htab_initialize(void) tce_alloc_start = base + size + 1; BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end, - __pa(tce_alloc_start), mode_rw, + __pa(tce_alloc_start), prot, mmu_linear_psize, mmu_kernel_ssize)); } @@ -1117,8 +1133,7 @@ static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi) unsigned long hash, hpteg; unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize); unsigned long va = hpt_va(vaddr, vsid, mmu_kernel_ssize); - unsigned long mode = _PAGE_ACCESSED | _PAGE_DIRTY | - _PAGE_COHERENT | PP_RWXX | HPTE_R_N; + unsigned long mode = htab_convert_pte_flags(PAGE_KERNEL); int ret; hash = hpt_hash(va, PAGE_SHIFT, mmu_kernel_ssize); diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c index 4f7df85129..036fe2f10c 100644 --- a/arch/powerpc/mm/init_64.c +++ b/arch/powerpc/mm/init_64.c @@ -206,13 +206,10 @@ static int __meminit vmemmap_populated(unsigned long start, int page_size) int __meminit vmemmap_populate(struct page *start_page, unsigned long nr_pages, int node) { - unsigned long mode_rw; unsigned long start = (unsigned long)start_page; unsigned long end = (unsigned long)(start_page + nr_pages); unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; - mode_rw = _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX; - /* Align to the page size of the linear mapping. */ start = _ALIGN_DOWN(start, page_size); @@ -230,9 +227,9 @@ int __meminit vmemmap_populate(struct page *start_page, pr_debug("vmemmap %08lx allocated at %p, physical %08lx.\n", start, p, __pa(p)); - mapped = htab_bolt_mapping(start, start + page_size, - __pa(p), mode_rw, mmu_vmemmap_psize, - mmu_kernel_ssize); + mapped = htab_bolt_mapping(start, start + page_size, __pa(p), + PAGE_KERNEL, mmu_vmemmap_psize, + mmu_kernel_ssize); BUG_ON(mapped < 0); } -- 2.39.5