arm64 fixes:

- Ensure that the compiler and linker versions are aligned so that ld
   doesn't complain about not understanding a .note.gnu.property section
   (emitted when pointer authentication is enabled).
 
 - Force -mbranch-protection=none when the feature is not enabled, in
   case a compiler may choose a different default value.
 
 - Remove CONFIG_DEBUG_ALIGN_RODATA. It was never in defconfig and rarely
   enabled.
 
 - Fix checking 16-bit Thumb-2 instructions checking mask in the
   emulation of the SETEND instruction (it could match the bottom half of
   a 32-bit Thumb-2 instruction).
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - Ensure that the compiler and linker versions are aligned so that ld
   doesn't complain about not understanding a .note.gnu.property section
   (emitted when pointer authentication is enabled).

 - Force -mbranch-protection=none when the feature is not enabled, in
   case a compiler may choose a different default value.

 - Remove CONFIG_DEBUG_ALIGN_RODATA. It was never in defconfig and
   rarely enabled.

 - Fix checking 16-bit Thumb-2 instructions checking mask in the
   emulation of the SETEND instruction (it could match the bottom half
   of a 32-bit Thumb-2 instruction).

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: armv8_deprecated: Fix undef_hook mask for thumb setend
  arm64: remove CONFIG_DEBUG_ALIGN_RODATA feature
  arm64: Always force a branch protection mode when the compiler has one
  arm64: Kconfig: ptrauth: Add binutils version check to fix mismatch
  init/kconfig: Add LD_VERSION Kconfig
This commit is contained in:
Linus Torvalds 2020-04-09 11:04:16 -07:00
commit 87ebc45d2d
7 changed files with 19 additions and 32 deletions

View File

@ -1502,7 +1502,10 @@ config ARM64_PTR_AUTH
default y
depends on !KVM || ARM64_VHE
depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC
depends on CC_IS_GCC || (CC_IS_CLANG && AS_HAS_CFI_NEGATE_RA_STATE)
# GCC 9.1 and later inserts a .note.gnu.property section note for PAC
# which is only understood by binutils starting with version 2.33.1.
depends on !CC_IS_GCC || GCC_VERSION < 90100 || LD_VERSION >= 233010000
depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS)
help
Pointer authentication (part of the ARMv8.3 Extensions) provides

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@ -52,19 +52,6 @@ config DEBUG_WX
If in doubt, say "Y".
config DEBUG_ALIGN_RODATA
depends on STRICT_KERNEL_RWX
bool "Align linker sections up to SECTION_SIZE"
help
If this option is enabled, sections that may potentially be marked as
read only or non-executable will be aligned up to the section size of
the kernel. This prevents sections from being split into pages and
avoids a potential TLB penalty. The downside is an increase in
alignment and potentially wasted space. Turn on this option if
performance is more important than memory pressure.
If in doubt, say N.
config DEBUG_EFI
depends on EFI && DEBUG_INFO
bool "UEFI debugging"

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@ -65,6 +65,10 @@ stack_protector_prepare: prepare0
include/generated/asm-offsets.h))
endif
# Ensure that if the compiler supports branch protection we default it
# off, this will be overridden if we are using branch protection.
branch-prot-flags-y += $(call cc-option,-mbranch-protection=none)
ifeq ($(CONFIG_ARM64_PTR_AUTH),y)
branch-prot-flags-$(CONFIG_CC_HAS_SIGN_RETURN_ADDRESS) := -msign-return-address=all
branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pac-ret+leaf
@ -73,9 +77,10 @@ branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pa
# we pass it only to the assembler. This option is utilized only in case of non
# integrated assemblers.
branch-prot-flags-$(CONFIG_AS_HAS_PAC) += -Wa,-march=armv8.3-a
KBUILD_CFLAGS += $(branch-prot-flags-y)
endif
KBUILD_CFLAGS += $(branch-prot-flags-y)
ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
KBUILD_CPPFLAGS += -mbig-endian
CHECKFLAGS += -D__AARCH64EB__

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@ -120,22 +120,12 @@
/*
* Alignment of kernel segments (e.g. .text, .data).
*/
#if defined(CONFIG_DEBUG_ALIGN_RODATA)
/*
* 4 KB granule: 1 level 2 entry
* 16 KB granule: 128 level 3 entries, with contiguous bit
* 64 KB granule: 32 level 3 entries, with contiguous bit
*/
#define SEGMENT_ALIGN SZ_2M
#else
/*
*
* 4 KB granule: 16 level 3 entries, with contiguous bit
* 16 KB granule: 4 level 3 entries, without contiguous bit
* 64 KB granule: 1 level 3 entry
*/
#define SEGMENT_ALIGN SZ_64K
#endif
/*
* Memory types available.

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@ -601,7 +601,7 @@ static struct undef_hook setend_hooks[] = {
},
{
/* Thumb mode */
.instr_mask = 0x0000fff7,
.instr_mask = 0xfffffff7,
.instr_val = 0x0000b650,
.pstate_mask = (PSR_AA32_T_BIT | PSR_AA32_MODE_MASK),
.pstate_val = (PSR_AA32_T_BIT | PSR_AA32_MODE_USR),

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@ -75,14 +75,12 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
/*
* If CONFIG_DEBUG_ALIGN_RODATA is not set, produce a
* displacement in the interval [0, MIN_KIMG_ALIGN) that
* doesn't violate this kernel's de-facto alignment
* Produce a displacement in the interval [0, MIN_KIMG_ALIGN)
* that doesn't violate this kernel's de-facto alignment
* constraints.
*/
u32 mask = (MIN_KIMG_ALIGN - 1) & ~(EFI_KIMG_ALIGN - 1);
u32 offset = !IS_ENABLED(CONFIG_DEBUG_ALIGN_RODATA) ?
(phys_seed >> 32) & mask : TEXT_OFFSET;
u32 offset = (phys_seed >> 32) & mask;
/*
* With CONFIG_RANDOMIZE_TEXT_OFFSET=y, TEXT_OFFSET may not

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@ -16,6 +16,10 @@ config GCC_VERSION
default $(shell,$(srctree)/scripts/gcc-version.sh $(CC)) if CC_IS_GCC
default 0
config LD_VERSION
int
default $(shell,$(LD) --version | $(srctree)/scripts/ld-version.sh)
config CC_IS_CLANG
def_bool $(success,$(CC) --version | head -n 1 | grep -q clang)