diff options
| author | Mark Kettenis <kettenis@cvs.openbsd.org> | 2018-04-06 19:09:06 +0000 |
|---|---|---|
| committer | Mark Kettenis <kettenis@cvs.openbsd.org> | 2018-04-06 19:09:06 +0000 |
| commit | 68744a33e1b6bcd838736f8b858ee47e60a12bfa (patch) | |
| tree | c411ed29a319aa6dcb3b2c27ab7c7357c35bc279 /sys/arch | |
| parent | 5ae64a7e9b370cdb4d071f05e2ebbe01402ecd28 (diff) | |
Sadly some UEFI frimware writes to mappings marked as runtime code so we can't
enforce W^X for runtime services. Do respect the bits that indicate that
mappings can be non-readable, non-executable or read-only though.
ok patrick@
Diffstat (limited to 'sys/arch')
| -rw-r--r-- | sys/arch/arm64/dev/efi.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/sys/arch/arm64/dev/efi.c b/sys/arch/arm64/dev/efi.c index 9a84863046f..cecaecf03d1 100644 --- a/sys/arch/arm64/dev/efi.c +++ b/sys/arch/arm64/dev/efi.c @@ -1,4 +1,4 @@ -/* $OpenBSD: efi.c,v 1.3 2018/01/12 14:52:55 kettenis Exp $ */ +/* $OpenBSD: efi.c,v 1.4 2018/04/06 19:09:05 kettenis Exp $ */ /* * Copyright (c) 2017 Mark Kettenis <kettenis@openbsd.org> @@ -125,7 +125,7 @@ efi_attach(struct device *parent, struct device *self, void *aux) vaddr_t va = desc->VirtualStart; paddr_t pa = desc->PhysicalStart; int npages = desc->NumberOfPages; - vm_prot_t prot = PROT_READ; + vm_prot_t prot = PROT_READ | PROT_WRITE; #ifdef EFI_DEBUG printf("type 0x%x pa 0x%llx va 0x%llx pages 0x%llx attr 0x%llx\n", @@ -142,10 +142,20 @@ efi_attach(struct device *parent, struct device *self, void *aux) if ((desc->Attribute & EFI_MEMORY_WB) == 0) pa |= PMAP_DEVICE; + /* + * Only make pages marked as runtime service code + * executable. This violates the standard but it + * seems we can get away with it. + */ if (desc->Type == EfiRuntimeServicesCode) prot |= PROT_EXEC; - else - prot |= PROT_WRITE; + + if (desc->Attribute & EFI_MEMORY_RP) + prot &= ~PROT_READ; + if (desc->Attribute & EFI_MEMORY_XP) + prot &= ~PROT_EXEC; + if (desc->Attribute & EFI_MEMORY_RO) + prot &= ~PROT_WRITE; while (npages--) { pmap_enter(sc->sc_pm, va, pa, prot, |