diff options
| -rw-r--r-- | arch/arm64/include/asm/futex.h | 2 | ||||
| -rw-r--r-- | arch/arm64/include/asm/page.h | 1 | ||||
| -rw-r--r-- | arch/arm64/mm/pageattr.c | 23 |
3 files changed, 22 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/futex.h b/arch/arm64/include/asm/futex.h index 007a69f..5f3ab8c 100644 --- a/arch/arm64/include/asm/futex.h +++ b/arch/arm64/include/asm/futex.h @@ -121,6 +121,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, return -EFAULT; asm volatile("// futex_atomic_cmpxchg_inatomic\n" +ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, CONFIG_ARM64_PAN) " prfm pstl1strm, %2\n" "1: ldxr %w1, %2\n" " sub %w3, %w1, %w4\n" @@ -137,6 +138,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, " .align 3\n" " .quad 1b, 4b, 2b, 4b\n" " .popsection\n" +ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN) : "+r" (ret), "=&r" (val), "+Q" (*uaddr), "=&r" (tmp) : "r" (oldval), "r" (newval), "Ir" (-EFAULT) : "memory"); diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h index 9b2f5a9..ae615b9 100644 --- a/arch/arm64/include/asm/page.h +++ b/arch/arm64/include/asm/page.h @@ -39,6 +39,7 @@ #ifndef __ASSEMBLY__ +#include <linux/personality.h> /* for READ_IMPLIES_EXEC */ #include <asm/pgtable-types.h> extern void __cpu_clear_user_page(void *p, unsigned long user); diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index cf62407..0795c3a 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -14,6 +14,7 @@ #include <linux/mm.h> #include <linux/module.h> #include <linux/sched.h> +#include <linux/vmalloc.h> #include <asm/pgtable.h> #include <asm/tlbflush.h> @@ -44,6 +45,7 @@ static int change_memory_common(unsigned long addr, int numpages, unsigned long end = start + size; int ret; struct page_change_data data; + struct vm_struct *area; if (!PAGE_ALIGNED(addr)) { start &= PAGE_MASK; @@ -51,10 +53,23 @@ static int change_memory_common(unsigned long addr, int numpages, WARN_ON_ONCE(1); } - if (start < MODULES_VADDR || start >= MODULES_END) - return -EINVAL; - - if (end < MODULES_VADDR || end >= MODULES_END) + /* + * Kernel VA mappings are always live, and splitting live section + * mappings into page mappings may cause TLB conflicts. This means + * we have to ensure that changing the permission bits of the range + * we are operating on does not result in such splitting. + * + * Let's restrict ourselves to mappings created by vmalloc (or vmap). + * Those are guaranteed to consist entirely of page mappings, and + * splitting is never needed. + * + * So check whether the [addr, addr + size) interval is entirely + * covered by precisely one VM area that has the VM_ALLOC flag set. + */ + area = find_vm_area((void *)addr); + if (!area || + end > (unsigned long)area->addr + area->size || + !(area->flags & VM_ALLOC)) return -EINVAL; if (!numpages) |