Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1215287

[PATCH v2] x86, efi, kasan: #undef memset/memcpy/memmove per arch.

Show all headers | View raw

In not-instrumented code KASAN replaces instrumented
memset/memcpy/memmove with not-instrumented analogues
__memset/__memcpy/__memove.
However, on x86 the EFI stub is not linked with the kernel.
It uses not-instrumented mem*() functions from
arch/x86/boot/compressed/string.c
So we don't replace them with __mem*() variants in EFI stub.

On ARM64 the EFI stub is linked with the kernel, so we should
replace mem*() functions with __mem*(), because the EFI stub
runs before KASAN sets up early shadow.

So let's move these #undef mem* into arch's asm/efi.h which is
also included by the EFI stub.

Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
---
 arch/x86/include/asm/efi.h             | 11 +++++++++++
 drivers/firmware/efi/libstub/efistub.h |  4 ----
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 155162e..6862f11 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -25,6 +25,17 @@
 #define EFI32_LOADER_SIGNATURE	"EL32"
 #define EFI64_LOADER_SIGNATURE	"EL64"
 
+/*
+ * Sometimes we may redefine memset to __memset.
+ * The EFI stub doesn't have __memset() because it's not
+ * linked with the kernel. So we should use standard
+ * memset from arch/x86/boot/compressed/string.c
+ * The same applies to memcpy and memmove.
+ */
+#undef memcpy
+#undef memset
+#undef memmove
+
 #ifdef CONFIG_X86_32
 
 
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index e334a01..6b6548f 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -5,10 +5,6 @@
 /* error code which can't be mistaken for valid address */
 #define EFI_ERROR	(~0UL)
 
-#undef memcpy
-#undef memset
-#undef memmove
-
 void efi_char16_printk(efi_system_table_t *, efi_char16_t *);
 
 efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg, void *__image,
-- 
2.4.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 0/4] KASAN/ARM64 EFI fixes Andrey Ryabinin <ryabinin.a.a@gmail.com> - 2015-08-26 18:20 +0200
  [PATCH 4/4] libfdt, kasan: don't instrument libfdt. Andrey Ryabinin <ryabinin.a.a@gmail.com> - 2015-08-26 18:20 +0200
  [PATCH 2/4] efi/runtime-wrappers, kasan: don't sanitize runtime wrappers. Andrey Ryabinin <ryabinin.a.a@gmail.com> - 2015-08-26 18:20 +0200
  [PATCH 1/4] x86, efi, kasan: #undef memset/memcpy/memmove per arch. Andrey Ryabinin <ryabinin.a.a@gmail.com> - 2015-08-26 18:20 +0200
    Re: [PATCH 1/4] x86, efi, kasan: #undef memset/memcpy/memmove per  arch. Ingo Molnar <mingo@kernel.org> - 2015-08-28 08:30 +0200
      Re: [PATCH 1/4] x86, efi, kasan: #undef memset/memcpy/memmove per  arch. Leif Lindholm <leif.lindholm@linaro.org> - 2015-08-28 10:40 +0200
        Re: [PATCH 1/4] x86, efi, kasan: #undef memset/memcpy/memmove per  arch. Ingo Molnar <mingo@kernel.org> - 2015-08-28 12:00 +0200
      [PATCH v2] x86, efi, kasan: #undef memset/memcpy/memmove per arch. Andrey Ryabinin <ryabinin.a.a@gmail.com> - 2015-08-28 13:20 +0200
        Re: [PATCH v2] x86, efi, kasan: #undef memset/memcpy/memmove per  arch. Matt Fleming <matt@codeblueprint.co.uk> - 2015-08-28 16:50 +0200
          Re: [PATCH v2] x86, efi, kasan: #undef memset/memcpy/memmove per arch. Andrey Ryabinin <ryabinin.a.a@gmail.com> - 2015-08-28 17:00 +0200
  [PATCH 3/4] arm64/efi-stub, kasan: don't instrument efi-stub. Andrey Ryabinin <ryabinin.a.a@gmail.com> - 2015-08-26 18:20 +0200

csiph-web