2014-02-14 07:24:35

by Borislav Petkov

Subject: [PATCH] x86, efi: Fix 32-bit fallout

From: Borislav Petkov <[email protected]>

We do not enable the new efi memmap on 32-bit and thus we need to run
runtime_code_page_mkexec() unconditionally there. Fix that.

Reported-and-tested-by: Lejun Zhu <[email protected]>
Cc: <[email protected]> # v3.14+
Signed-off-by: Borislav Petkov <[email protected]>
---
arch/x86/include/asm/efi.h | 2 ++
arch/x86/platform/efi/efi.c | 8 +++-----
arch/x86/platform/efi/efi_32.c | 6 ++++++
arch/x86/platform/efi/efi_64.c | 9 +++++++++
4 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index d3c099f53ff2..7fd9830285e0 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -133,6 +133,8 @@ extern int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
extern void efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages);
extern void __init old_map_region(efi_memory_desc_t *md);
extern void __init efi_dump_pagetable(void);
+extern void __init runtime_code_page_mkexec(void);
+extern void __init efi_runtime_mkexec(void);

struct efi_setup_data {
u64 fw_vendor;
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 0c8672b3f9a3..40e62ea52864 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -776,7 +776,7 @@ void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
set_memory_nx(addr, npages);
}

-static void __init runtime_code_page_mkexec(void)
+void __init runtime_code_page_mkexec(void)
{
efi_memory_desc_t *md;
void *p;
@@ -1024,8 +1024,7 @@ static void __init kexec_enter_virtual_mode(void)
efi.update_capsule = virt_efi_update_capsule;
efi.query_capsule_caps = virt_efi_query_capsule_caps;

- if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
- runtime_code_page_mkexec();
+ efi_runtime_mkexec();

/* clean DUMMY object */
efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
@@ -1125,8 +1124,7 @@ static void __init __efi_enter_virtual_mode(void)
efi.update_capsule = virt_efi_update_capsule;
efi.query_capsule_caps = virt_efi_query_capsule_caps;

- if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
- runtime_code_page_mkexec();
+ efi_runtime_mkexec();

/*
* We mapped the descriptor array into the EFI pagetable above but we're
diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
index 7ad87ee09525..9ee3491e31fb 100644
--- a/arch/x86/platform/efi/efi_32.c
+++ b/arch/x86/platform/efi/efi_32.c
@@ -82,3 +82,9 @@ void efi_call_phys_epilog(void)

local_irq_restore(efi_rt_eflags);
}
+
+void __init efi_runtime_mkexec(void)
+{
+ if (__supported_pte_mask & _PAGE_NX)
+ runtime_code_page_mkexec();
+}
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 0998f3a536ff..50cc39be2271 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -268,3 +268,12 @@ void __init efi_dump_pagetable(void)
ptdump_walk_pgd_level(NULL, pgd);
#endif
}
+
+void __init efi_runtime_mkexec(void)
+{
+ if (!efi_enabled(EFI_OLD_MEMMAP))
+ return;
+
+ if (__supported_pte_mask & _PAGE_NX)
+ runtime_code_page_mkexec();
+}
--
1.8.5.2.192.g7794a68

2014-02-14 09:22:32

by Matt Fleming

Subject: Re: [PATCH] x86, efi: Fix 32-bit fallout

On Fri, 14 Feb, at 08:24:24AM, Borislav Petkov wrote:
> From: Borislav Petkov <[email protected]>
>
> We do not enable the new efi memmap on 32-bit and thus we need to run
> runtime_code_page_mkexec() unconditionally there. Fix that.
>
> Reported-and-tested-by: Lejun Zhu <[email protected]>
> Cc: <[email protected]> # v3.14+
> Signed-off-by: Borislav Petkov <[email protected]>

Should this definitely be tagged for -stable? I'm not sure it makes
sense to backport your EFI memmap rototill, so this has only been broken
since v3.14-rc1.

--
Matt Fleming, Intel Open Source Technology Center