Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - Clean-ups following the merging window: remove unused variable,
   duplicate includes, superfluous barrier, move some inline asm to
   separate functions.

 - Disable top-byte-ignore on kernel code addresses with KASAN/MTE
   enabled (already done when MTE is disabled).

 - Fix ARCH_LOW_ADDRESS_LIMIT definition with CONFIG_ZONE_DMA disabled.

 - Compiler/linker flags: link with "-z norelno", discard .eh_frame_hdr
   instead of --no-eh-frame-hdr.

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Move PSTATE.TCO setting to separate functions
  arm64: kasan: Set TCR_EL1.TBID1 when KASAN_HW_TAGS is enabled
  arm64: vdso: disable .eh_frame_hdr via /DISCARD/ instead of --no-eh-frame-hdr
  arm64: traps: remove duplicate include statement
  arm64: link with -z norelro for LLD or aarch64-elf
  arm64: mm: Fix ARCH_LOW_ADDRESS_LIMIT when !CONFIG_ZONE_DMA
  arm64: mte: remove an ISB on kernel exit
  arm64/smp: Remove unused irq variable in arch_show_interrupts()

arch/arm64/Makefile

@@ -10,7 +10,7 @@
 #
 # Copyright (C) 1995-2001 by Russell King
 
-LDFLAGS_vmlinux	:=--no-undefined -X -z norelro
+LDFLAGS_vmlinux	:=--no-undefined -X
 
 ifeq ($(CONFIG_RELOCATABLE), y)
 # Pass --no-apply-dynamic-relocs to restore pre-binutils-2.27 behaviour
@@ -115,16 +115,20 @@ KBUILD_CPPFLAGS	+= -mbig-endian
 CHECKFLAGS	+= -D__AARCH64EB__
 # Prefer the baremetal ELF build target, but not all toolchains include
 # it so fall back to the standard linux version if needed.
-KBUILD_LDFLAGS	+= -EB $(call ld-option, -maarch64elfb, -maarch64linuxb)
+KBUILD_LDFLAGS	+= -EB $(call ld-option, -maarch64elfb, -maarch64linuxb -z norelro)
 UTS_MACHINE	:= aarch64_be
 else
 KBUILD_CPPFLAGS	+= -mlittle-endian
 CHECKFLAGS	+= -D__AARCH64EL__
 # Same as above, prefer ELF but fall back to linux target if needed.
-KBUILD_LDFLAGS	+= -EL $(call ld-option, -maarch64elf, -maarch64linux)
+KBUILD_LDFLAGS	+= -EL $(call ld-option, -maarch64elf, -maarch64linux -z norelro)
 UTS_MACHINE	:= aarch64
 endif
 
+ifeq ($(CONFIG_LD_IS_LLD), y)
+KBUILD_LDFLAGS	+= -z norelro
+endif
+
 CHECKFLAGS	+= -D__aarch64__
 
 ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)

arch/arm64/include/asm/processor.h

@@ -94,7 +94,8 @@
 #endif /* CONFIG_ARM64_FORCE_52BIT */
 
 extern phys_addr_t arm64_dma_phys_limit;
-#define ARCH_LOW_ADDRESS_LIMIT	(arm64_dma_phys_limit - 1)
+extern phys_addr_t arm64_dma32_phys_limit;
+#define ARCH_LOW_ADDRESS_LIMIT	((arm64_dma_phys_limit ? : arm64_dma32_phys_limit) - 1)
 
 struct debug_info {
 #ifdef CONFIG_HAVE_HW_BREAKPOINT

arch/arm64/include/asm/uaccess.h

@@ -176,10 +176,21 @@ static inline void __uaccess_enable_hw_pan(void)
  * The Tag check override (TCO) bit disables temporarily the tag checking
  * preventing the issue.
  */
-static inline void uaccess_disable_privileged(void)
+static inline void __uaccess_disable_tco(void)
 {
 	asm volatile(ALTERNATIVE("nop", SET_PSTATE_TCO(0),
 				 ARM64_MTE, CONFIG_KASAN_HW_TAGS));
+}
+
+static inline void __uaccess_enable_tco(void)
+{
+	asm volatile(ALTERNATIVE("nop", SET_PSTATE_TCO(1),
+				 ARM64_MTE, CONFIG_KASAN_HW_TAGS));
+}
+
+static inline void uaccess_disable_privileged(void)
+{
+	__uaccess_disable_tco();
 
 	if (uaccess_ttbr0_disable())
 		return;
@@ -189,8 +200,7 @@ static inline void uaccess_disable_privileged(void)
 
 static inline void uaccess_enable_privileged(void)
 {
-	asm volatile(ALTERNATIVE("nop", SET_PSTATE_TCO(1),
-				 ARM64_MTE, CONFIG_KASAN_HW_TAGS));
+	__uaccess_enable_tco();
 
 	if (uaccess_ttbr0_enable())
 		return;

arch/arm64/kernel/entry.S

@@ -182,7 +182,6 @@ alternative_else_nop_endif
 	mrs_s	\tmp2, SYS_GCR_EL1
 	bfi	\tmp2, \tmp, #0, #16
 	msr_s	SYS_GCR_EL1, \tmp2
-	isb
 #endif
 	.endm
 
@@ -194,6 +193,7 @@ alternative_else_nop_endif
 	ldr_l	\tmp, gcr_kernel_excl
 
 	mte_set_gcr \tmp, \tmp2
+	isb
 1:
 #endif
 	.endm

arch/arm64/kernel/smp.c

@@ -807,7 +807,6 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 	unsigned int cpu, i;
 
 	for (i = 0; i < NR_IPI; i++) {
-		unsigned int irq = irq_desc_get_irq(ipi_desc[i]);
 		seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
 			   prec >= 4 ? " " : "");
 		for_each_online_cpu(cpu)

arch/arm64/kernel/traps.c

@@ -42,7 +42,6 @@
 #include <asm/smp.h>
 #include <asm/stack_pointer.h>
 #include <asm/stacktrace.h>
-#include <asm/exception.h>
 #include <asm/system_misc.h>
 #include <asm/sysreg.h>
 

arch/arm64/kernel/vdso/Makefile

@@ -24,8 +24,7 @@ btildflags-$(CONFIG_ARM64_BTI_KERNEL) += -z force-bti
 # routines, as x86 does (see 6f121e548f83 ("x86, vdso: Reimplement vdso.so
 # preparation in build-time C")).
 ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv	\
-	     -Bsymbolic $(call ld-option, --no-eh-frame-hdr) --build-id=sha1 -n	\
-	     $(btildflags-y) -T
+	     -Bsymbolic --build-id=sha1 -n $(btildflags-y) -T
 
 ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18
 ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO

arch/arm64/kernel/vdso/vdso.lds.S

@@ -40,9 +40,6 @@ SECTIONS
 	PROVIDE (_etext = .);
 	PROVIDE (etext = .);
 
-	.eh_frame_hdr	: { *(.eh_frame_hdr) }		:text	:eh_frame_hdr
-	.eh_frame	: { KEEP (*(.eh_frame)) }	:text
-
 	.dynamic	: { *(.dynamic) }		:text	:dynamic
 
 	.rodata		: { *(.rodata*) }		:text
@@ -54,6 +51,7 @@ SECTIONS
 		*(.note.GNU-stack)
 		*(.data .data.* .gnu.linkonce.d.* .sdata*)
 		*(.bss .sbss .dynbss .dynsbss)
+		*(.eh_frame .eh_frame_hdr)
 	}
 }
 
@@ -66,7 +64,6 @@ PHDRS
 	text		PT_LOAD		FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
 	dynamic		PT_DYNAMIC	FLAGS(4);		/* PF_R */
 	note		PT_NOTE		FLAGS(4);		/* PF_R */
-	eh_frame_hdr	PT_GNU_EH_FRAME;
 }
 
 /*

arch/arm64/mm/init.c

@@ -59,7 +59,7 @@ EXPORT_SYMBOL(memstart_addr);
  * bit addressable memory area.
  */
 phys_addr_t arm64_dma_phys_limit __ro_after_init;
-static phys_addr_t arm64_dma32_phys_limit __ro_after_init;
+phys_addr_t arm64_dma32_phys_limit __ro_after_init;
 
 #ifdef CONFIG_KEXEC_CORE
 /*

arch/arm64/mm/proc.S

@@ -46,7 +46,7 @@
 #endif
 
 #ifdef CONFIG_KASAN_HW_TAGS
-#define TCR_KASAN_HW_FLAGS SYS_TCR_EL1_TCMA1 | TCR_TBI1
+#define TCR_KASAN_HW_FLAGS SYS_TCR_EL1_TCMA1 | TCR_TBI1 | TCR_TBID1
 #else
 #define TCR_KASAN_HW_FLAGS 0
 #endif