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authorLinus Torvalds <torvalds@linux-foundation.org>2020-04-09 11:04:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-09 11:04:16 -0700
commit87ebc45d2d32936fb1c8242032eb0b9bcd058858 (patch)
treed5f32252db7a56da284f22a2837ebfa13f78bbd7 /arch
parente4da01d8333e500e15a674d75885a9dfcfd31e77 (diff)
parentfc2266011accd5aeb8ebc335c381991f20e26e33 (diff)
downloadlinux-87ebc45d2d32936fb1c8242032eb0b9bcd058858.tar.gz
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
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/Kconfig5
-rw-r--r--arch/arm64/Kconfig.debug13
-rw-r--r--arch/arm64/Makefile7
-rw-r--r--arch/arm64/include/asm/memory.h12
-rw-r--r--arch/arm64/kernel/armv8_deprecated.c2
5 files changed, 12 insertions, 27 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 6e41c4b62607..40fb05d96c60 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -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
diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug
index 1c906d932d6b..a1efa246c9ed 100644
--- a/arch/arm64/Kconfig.debug
+++ b/arch/arm64/Kconfig.debug
@@ -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"
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index f15f92ba53e6..85e4149cc5d5 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -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__
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 2be67b232499..a1871bb32bb1 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -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.
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index 4cc581af2d96..c19aa81ddc8c 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -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),