diff options
Diffstat (limited to 'arch/i386/mm')
| -rw-r--r-- | arch/i386/mm/init.c | 24 | ||||
| -rw-r--r-- | arch/i386/mm/ioremap.c | 37 | ||||
| -rw-r--r-- | arch/i386/mm/pageattr.c | 27 |
3 files changed, 74 insertions, 14 deletions
diff --git a/arch/i386/mm/init.c b/arch/i386/mm/init.c index 06e26f0..7df494b 100644 --- a/arch/i386/mm/init.c +++ b/arch/i386/mm/init.c @@ -735,6 +735,30 @@ void free_initmem(void) printk (KERN_INFO "Freeing unused kernel memory: %dk freed\n", (__init_end - __init_begin) >> 10); } +#ifdef CONFIG_DEBUG_RODATA + +extern char __start_rodata, __end_rodata; +void mark_rodata_ro(void) +{ + unsigned long addr = (unsigned long)&__start_rodata; + + for (; addr < (unsigned long)&__end_rodata; addr += PAGE_SIZE) + change_page_attr(virt_to_page(addr), 1, PAGE_KERNEL_RO); + + printk ("Write protecting the kernel read-only data: %luk\n", + (unsigned long)(&__end_rodata - &__start_rodata) >> 10); + + /* + * change_page_attr() requires a global_flush_tlb() call after it. + * We do this after the printk so that if something went wrong in the + * change, the printk gets out at least to give a better debug hint + * of who is the culprit. + */ + global_flush_tlb(); +} +#endif + + #ifdef CONFIG_BLK_DEV_INITRD void free_initrd_mem(unsigned long start, unsigned long end) { diff --git a/arch/i386/mm/ioremap.c b/arch/i386/mm/ioremap.c index 5d09de8..247fde7 100644 --- a/arch/i386/mm/ioremap.c +++ b/arch/i386/mm/ioremap.c @@ -223,9 +223,15 @@ void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size) } EXPORT_SYMBOL(ioremap_nocache); +/** + * iounmap - Free a IO remapping + * @addr: virtual address from ioremap_* + * + * Caller must ensure there is only one unmapping for the same pointer. + */ void iounmap(volatile void __iomem *addr) { - struct vm_struct *p; + struct vm_struct *p, *o; if ((void __force *)addr <= high_memory) return; @@ -239,22 +245,37 @@ void iounmap(volatile void __iomem *addr) addr < phys_to_virt(ISA_END_ADDRESS)) return; - write_lock(&vmlist_lock); - p = __remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr)); - if (!p) { - printk(KERN_WARNING "iounmap: bad address %p\n", addr); + addr = (volatile void __iomem *)(PAGE_MASK & (unsigned long __force)addr); + + /* Use the vm area unlocked, assuming the caller + ensures there isn't another iounmap for the same address + in parallel. Reuse of the virtual address is prevented by + leaving it in the global lists until we're done with it. + cpa takes care of the direct mappings. */ + read_lock(&vmlist_lock); + for (p = vmlist; p; p = p->next) { + if (p->addr == addr) + break; + } + read_unlock(&vmlist_lock); + + if (!p) { + printk("iounmap: bad address %p\n", addr); dump_stack(); - goto out_unlock; + return; } + /* Reset the direct mapping. Can block */ if ((p->flags >> 20) && p->phys_addr < virt_to_phys(high_memory) - 1) { change_page_attr(virt_to_page(__va(p->phys_addr)), p->size >> PAGE_SHIFT, PAGE_KERNEL); global_flush_tlb(); } -out_unlock: - write_unlock(&vmlist_lock); + + /* Finally remove it */ + o = remove_vm_area((void *)addr); + BUG_ON(p != o || o == NULL); kfree(p); } EXPORT_SYMBOL(iounmap); diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c index f600fc2..c30a16d 100644 --- a/arch/i386/mm/pageattr.c +++ b/arch/i386/mm/pageattr.c @@ -13,6 +13,7 @@ #include <asm/processor.h> #include <asm/tlbflush.h> #include <asm/pgalloc.h> +#include <asm/sections.h> static DEFINE_SPINLOCK(cpa_lock); static struct list_head df_list = LIST_HEAD_INIT(df_list); @@ -36,7 +37,8 @@ pte_t *lookup_address(unsigned long address) return pte_offset_kernel(pmd, address); } -static struct page *split_large_page(unsigned long address, pgprot_t prot) +static struct page *split_large_page(unsigned long address, pgprot_t prot, + pgprot_t ref_prot) { int i; unsigned long addr; @@ -54,7 +56,7 @@ static struct page *split_large_page(unsigned long address, pgprot_t prot) pbase = (pte_t *)page_address(base); for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) { set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT, - addr == address ? prot : PAGE_KERNEL)); + addr == address ? prot : ref_prot)); } return base; } @@ -98,11 +100,18 @@ static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte) */ static inline void revert_page(struct page *kpte_page, unsigned long address) { - pte_t *linear = (pte_t *) + pgprot_t ref_prot; + pte_t *linear; + + ref_prot = + ((address & LARGE_PAGE_MASK) < (unsigned long)&_etext) + ? PAGE_KERNEL_LARGE_EXEC : PAGE_KERNEL_LARGE; + + linear = (pte_t *) pmd_offset(pud_offset(pgd_offset_k(address), address), address); set_pmd_pte(linear, address, pfn_pte((__pa(address) & LARGE_PAGE_MASK) >> PAGE_SHIFT, - PAGE_KERNEL_LARGE)); + ref_prot)); } static int @@ -123,10 +132,16 @@ __change_page_attr(struct page *page, pgprot_t prot) if ((pte_val(*kpte) & _PAGE_PSE) == 0) { set_pte_atomic(kpte, mk_pte(page, prot)); } else { - struct page *split = split_large_page(address, prot); + pgprot_t ref_prot; + struct page *split; + + ref_prot = + ((address & LARGE_PAGE_MASK) < (unsigned long)&_etext) + ? PAGE_KERNEL_EXEC : PAGE_KERNEL; + split = split_large_page(address, prot, ref_prot); if (!split) return -ENOMEM; - set_pmd_pte(kpte,address,mk_pte(split, PAGE_KERNEL)); + set_pmd_pte(kpte,address,mk_pte(split, ref_prot)); kpte_page = split; } get_page(kpte_page); |
