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

Pull more arm64 fixes from Will Deacon:

 - Fix incorrect LDADD instruction encoding in our disassembly macros

 - Disable the broken ARM64_PSEUDO_NMI support for now

 - Add workaround for Cortex-A76 CPU erratum #1463225

 - Handle Cortex-A76/Neoverse-N1 erratum #1418040 w/ existing workaround

 - Fix IORT build failure if IOMMU_SUPPORT=n

 - Fix place-relative module relocation range checking and its
   interaction with KASLR

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: insn: Add BUILD_BUG_ON() for invalid masks
  arm64: insn: Fix ldadd instruction encoding
  arm64: Kconfig: Make ARM64_PSEUDO_NMI depend on BROKEN for now
  arm64: Handle erratum 1418040 as a superset of erratum 1188873
  arm64/module: deal with ambiguity in PRELxx relocation ranges
  ACPI/IORT: Fix build error when IOMMU_SUPPORT is disabled
  arm64/kernel: kaslr: reduce module randomization range to 2 GB
  arm64: errata: Add workaround for Cortex-A76 erratum #1463225
  arm64: Remove useless message during oops

10 files changed, 159 insertions, 34 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index ca9c175fb949..697ea0510729 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -476,16 +476,15 @@ config ARM64_ERRATUM_1024718
 
 	  If unsure, say Y.
 
-config ARM64_ERRATUM_1188873
+config ARM64_ERRATUM_1418040
 	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
 	default y
 	depends on COMPAT
-	select ARM_ARCH_TIMER_OOL_WORKAROUND
 	help
 	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
-	  erratum 1188873.
+	  errata 1188873 and 1418040.
 
-	  Affected Cortex-A76/Neoverse-N1 cores (r0p0, r1p0, r2p0) could
+	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
 	  cause register corruption when accessing the timer registers
 	  from AArch32 userspace.
 
@@ -521,6 +520,24 @@ config ARM64_ERRATUM_1286807
 
 	  If unsure, say Y.
 
+config ARM64_ERRATUM_1463225
+	bool "Cortex-A76: Software Step might prevent interrupt recognition"
+	default y
+	help
+	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
+
+	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
+	  of a system call instruction (SVC) can prevent recognition of
+	  subsequent interrupts when software stepping is disabled in the
+	  exception handler of the system call and either kernel debugging
+	  is enabled or VHE is in use.
+
+	  Work around the erratum by triggering a dummy step exception
+	  when handling a system call from a task that is being stepped
+	  in a VHE configuration of the kernel.
+
+	  If unsure, say Y.
+
 config CAVIUM_ERRATUM_22375
 	bool "Cavium erratum 22375, 24313"
 	default y
@@ -1406,6 +1423,7 @@ config ARM64_MODULE_PLTS
 
 config ARM64_PSEUDO_NMI
 	bool "Support for NMI-like interrupts"
+	depends on BROKEN # 1556553607-46531-1-git-send-email-julien.thierry@arm.com
 	select CONFIG_ARM_GIC_V3
 	help
 	  Adds support for mimicking Non-Maskable Interrupts through the use of
diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index defdc67d9ab4..33401ebc187c 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -53,7 +53,7 @@
 #define ARM64_HAS_STAGE2_FWB			32
 #define ARM64_HAS_CRC32				33
 #define ARM64_SSBS				34
-#define ARM64_WORKAROUND_1188873		35
+#define ARM64_WORKAROUND_1418040		35
 #define ARM64_HAS_SB				36
 #define ARM64_WORKAROUND_1165522		37
 #define ARM64_HAS_ADDRESS_AUTH_ARCH		38
@@ -62,7 +62,8 @@
 #define ARM64_HAS_GENERIC_AUTH_IMP_DEF		41
 #define ARM64_HAS_IRQ_PRIO_MASKING		42
 #define ARM64_HAS_DCPODP			43
+#define ARM64_WORKAROUND_1463225		44
 
-#define ARM64_NCAPS				44
+#define ARM64_NCAPS				45
 
 #endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h
index ec894de0ed4e..87fdfba13a30 100644
--- a/arch/arm64/include/asm/insn.h
+++ b/arch/arm64/include/asm/insn.h
@@ -18,6 +18,7 @@
  */
 #ifndef	__ASM_INSN_H
 #define	__ASM_INSN_H
+#include <linux/build_bug.h>
 #include <linux/types.h>
 
 /* A64 instructions are always 32 bits. */
@@ -266,18 +267,23 @@ enum aarch64_insn_adr_type {
 	AARCH64_INSN_ADR_TYPE_ADR,
 };
 
-#define	__AARCH64_INSN_FUNCS(abbr, mask, val)	\
-static __always_inline bool aarch64_insn_is_##abbr(u32 code) \
-{ return (code & (mask)) == (val); } \
-static __always_inline u32 aarch64_insn_get_##abbr##_value(void) \
-{ return (val); }
+#define	__AARCH64_INSN_FUNCS(abbr, mask, val)				\
+static __always_inline bool aarch64_insn_is_##abbr(u32 code)		\
+{									\
+	BUILD_BUG_ON(~(mask) & (val));					\
+	return (code & (mask)) == (val);				\
+}									\
+static __always_inline u32 aarch64_insn_get_##abbr##_value(void)	\
+{									\
+	return (val);							\
+}
 
 __AARCH64_INSN_FUNCS(adr,	0x9F000000, 0x10000000)
 __AARCH64_INSN_FUNCS(adrp,	0x9F000000, 0x90000000)
 __AARCH64_INSN_FUNCS(prfm,	0x3FC00000, 0x39800000)
 __AARCH64_INSN_FUNCS(prfm_lit,	0xFF000000, 0xD8000000)
 __AARCH64_INSN_FUNCS(str_reg,	0x3FE0EC00, 0x38206800)
-__AARCH64_INSN_FUNCS(ldadd,	0x3F20FC00, 0xB8200000)
+__AARCH64_INSN_FUNCS(ldadd,	0x3F20FC00, 0x38200000)
 __AARCH64_INSN_FUNCS(ldr_reg,	0x3FE0EC00, 0x38606800)
 __AARCH64_INSN_FUNCS(ldr_lit,	0xBF000000, 0x18000000)
 __AARCH64_INSN_FUNCS(ldrsw_lit,	0xFF000000, 0x98000000)
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index e88d4e7bdfc7..d61beedba101 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -502,6 +502,22 @@ static const struct midr_range arm64_ssb_cpus[] = {
 	{},
 };
 
+#ifdef CONFIG_ARM64_ERRATUM_1463225
+DEFINE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa);
+
+static bool
+has_cortex_a76_erratum_1463225(const struct arm64_cpu_capabilities *entry,
+			       int scope)
+{
+	u32 midr = read_cpuid_id();
+	/* Cortex-A76 r0p0 - r3p1 */
+	struct midr_range range = MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 3, 1);
+
+	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
+	return is_midr_in_range(midr, &range) && is_kernel_in_hyp_mode();
+}
+#endif
+
 static void __maybe_unused
 cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused)
 {
@@ -682,12 +698,16 @@ static const struct midr_range workaround_clean_cache[] = {
 };
 #endif
 
-#ifdef CONFIG_ARM64_ERRATUM_1188873
-static const struct midr_range erratum_1188873_list[] = {
-	/* Cortex-A76 r0p0 to r2p0 */
-	MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 2, 0),
-	/* Neoverse-N1 r0p0 to r2p0 */
-	MIDR_RANGE(MIDR_NEOVERSE_N1, 0, 0, 2, 0),
+#ifdef CONFIG_ARM64_ERRATUM_1418040
+/*
+ * - 1188873 affects r0p0 to r2p0
+ * - 1418040 affects r0p0 to r3p1
+ */
+static const struct midr_range erratum_1418040_list[] = {
+	/* Cortex-A76 r0p0 to r3p1 */
+	MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 3, 1),
+	/* Neoverse-N1 r0p0 to r3p1 */
+	MIDR_RANGE(MIDR_NEOVERSE_N1, 0, 0, 3, 1),
 	{},
 };
 #endif
@@ -809,11 +829,11 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 		.matches = has_ssbd_mitigation,
 		.midr_range_list = arm64_ssb_cpus,
 	},
-#ifdef CONFIG_ARM64_ERRATUM_1188873
+#ifdef CONFIG_ARM64_ERRATUM_1418040
 	{
-		.desc = "ARM erratum 1188873",
-		.capability = ARM64_WORKAROUND_1188873,
-		ERRATA_MIDR_RANGE_LIST(erratum_1188873_list),
+		.desc = "ARM erratum 1418040",
+		.capability = ARM64_WORKAROUND_1418040,
+		ERRATA_MIDR_RANGE_LIST(erratum_1418040_list),
 	},
 #endif
 #ifdef CONFIG_ARM64_ERRATUM_1165522
@@ -824,6 +844,14 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 		ERRATA_MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 2, 0),
 	},
 #endif
+#ifdef CONFIG_ARM64_ERRATUM_1463225
+	{
+		.desc = "ARM erratum 1463225",
+		.capability = ARM64_WORKAROUND_1463225,
+		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
+		.matches = has_cortex_a76_erratum_1463225,
+	},
+#endif
 	{
 	}
 };
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 1a7811b7e3c4..cd0c7af8e4a8 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -336,8 +336,8 @@ alternative_if ARM64_WORKAROUND_845719
 alternative_else_nop_endif
 #endif
 3:
-#ifdef CONFIG_ARM64_ERRATUM_1188873
-alternative_if_not ARM64_WORKAROUND_1188873
+#ifdef CONFIG_ARM64_ERRATUM_1418040
+alternative_if_not ARM64_WORKAROUND_1418040
 	b	4f
 alternative_else_nop_endif
 	/*
diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
index b09b6f75f759..06941c1fe418 100644
--- a/arch/arm64/kernel/kaslr.c
+++ b/arch/arm64/kernel/kaslr.c
@@ -145,15 +145,15 @@ u64 __init kaslr_early_init(u64 dt_phys)
 
 	if (IS_ENABLED(CONFIG_RANDOMIZE_MODULE_REGION_FULL)) {
 		/*
-		 * Randomize the module region over a 4 GB window covering the
+		 * Randomize the module region over a 2 GB window covering the
 		 * kernel. This reduces the risk of modules leaking information
 		 * about the address of the kernel itself, but results in
 		 * branches between modules and the core kernel that are
 		 * resolved via PLTs. (Branches between modules will be
 		 * resolved normally.)
 		 */
-		module_range = SZ_4G - (u64)(_end - _stext);
-		module_alloc_base = max((u64)_end + offset - SZ_4G,
+		module_range = SZ_2G - (u64)(_end - _stext);
+		module_alloc_base = max((u64)_end + offset - SZ_2G,
 					(u64)MODULES_VADDR);
 	} else {
 		/*
diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index f713e2fc4d75..f32359cffb01 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -56,7 +56,7 @@ void *module_alloc(unsigned long size)
 		 * can simply omit this fallback in that case.
 		 */
 		p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
-				module_alloc_base + SZ_4G, GFP_KERNEL,
+				module_alloc_base + SZ_2G, GFP_KERNEL,
 				PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
 				__builtin_return_address(0));
 
@@ -96,15 +96,27 @@ static int reloc_data(enum aarch64_reloc_op op, void *place, u64 val, int len)
 {
 	s64 sval = do_reloc(op, place, val);
 
+	/*
+	 * The ELF psABI for AArch64 documents the 16-bit and 32-bit place
+	 * relative relocations as having a range of [-2^15, 2^16) or
+	 * [-2^31, 2^32), respectively. However, in order to be able to detect
+	 * overflows reliably, we have to choose whether we interpret such
+	 * quantities as signed or as unsigned, and stick with it.
+	 * The way we organize our address space requires a signed
+	 * interpretation of 32-bit relative references, so let's use that
+	 * for all R_AARCH64_PRELxx relocations. This means our upper
+	 * bound for overflow detection should be Sxx_MAX rather than Uxx_MAX.
+	 */
+
 	switch (len) {
 	case 16:
 		*(s16 *)place = sval;
-		if (sval < S16_MIN || sval > U16_MAX)
+		if (sval < S16_MIN || sval > S16_MAX)
 			return -ERANGE;
 		break;
 	case 32:
 		*(s32 *)place = sval;
-		if (sval < S32_MIN || sval > U32_MAX)
+		if (sval < S32_MIN || sval > S32_MAX)
 			return -ERANGE;
 		break;
 	case 64:
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index 5610ac01c1ec..871c739f060a 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -8,6 +8,7 @@
 #include <linux/syscalls.h>
 
 #include <asm/daifflags.h>
+#include <asm/debug-monitors.h>
 #include <asm/fpsimd.h>
 #include <asm/syscall.h>
 #include <asm/thread_info.h>
@@ -60,6 +61,35 @@ static inline bool has_syscall_work(unsigned long flags)
 int syscall_trace_enter(struct pt_regs *regs);
 void syscall_trace_exit(struct pt_regs *regs);
 
+#ifdef CONFIG_ARM64_ERRATUM_1463225
+DECLARE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa);
+
+static void cortex_a76_erratum_1463225_svc_handler(void)
+{
+	u32 reg, val;
+
+	if (!unlikely(test_thread_flag(TIF_SINGLESTEP)))
+		return;
+
+	if (!unlikely(this_cpu_has_cap(ARM64_WORKAROUND_1463225)))
+		return;
+
+	__this_cpu_write(__in_cortex_a76_erratum_1463225_wa, 1);
+	reg = read_sysreg(mdscr_el1);
+	val = reg | DBG_MDSCR_SS | DBG_MDSCR_KDE;
+	write_sysreg(val, mdscr_el1);
+	asm volatile("msr daifclr, #8");
+	isb();
+
+	/* We will have taken a single-step exception by this point */
+
+	write_sysreg(reg, mdscr_el1);
+	__this_cpu_write(__in_cortex_a76_erratum_1463225_wa, 0);
+}
+#else
+static void cortex_a76_erratum_1463225_svc_handler(void) { }
+#endif /* CONFIG_ARM64_ERRATUM_1463225 */
+
 static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
 			   const syscall_fn_t syscall_table[])
 {
@@ -68,6 +98,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
 	regs->orig_x0 = regs->regs[0];
 	regs->syscallno = scno;
 
+	cortex_a76_erratum_1463225_svc_handler();
 	local_daif_restore(DAIF_PROCCTX);
 	user_exit();
 
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index ade32046f3fe..e6be1a6efc0a 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -168,7 +168,6 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
 
 static int __die(const char *str, int err, struct pt_regs *regs)
 {
-	struct task_struct *tsk = current;
 	static int die_counter;
 	int ret;
 
@@ -181,9 +180,6 @@ static int __die(const char *str, int err, struct pt_regs *regs)
 		return ret;
 
 	print_modules();
-	pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
-		 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk),
-		 end_of_stack(tsk));
 	show_regs(regs);
 
 	if (!user_mode(regs))
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index dda234bcc020..a30818ed9c60 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -811,6 +811,36 @@ void __init hook_debug_fault_code(int nr,
 	debug_fault_info[nr].name	= name;
 }
 
+#ifdef CONFIG_ARM64_ERRATUM_1463225
+DECLARE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa);
+
+static int __exception
+cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs)
+{
+	if (user_mode(regs))
+		return 0;
+
+	if (!__this_cpu_read(__in_cortex_a76_erratum_1463225_wa))
+		return 0;
+
+	/*
+	 * We've taken a dummy step exception from the kernel to ensure
+	 * that interrupts are re-enabled on the syscall path. Return back
+	 * to cortex_a76_erratum_1463225_svc_handler() with debug exceptions
+	 * masked so that we can safely restore the mdscr and get on with
+	 * handling the syscall.
+	 */
+	regs->pstate |= PSR_D_BIT;
+	return 1;
+}
+#else
+static int __exception
+cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs)
+{
+	return 0;
+}
+#endif /* CONFIG_ARM64_ERRATUM_1463225 */
+
 asmlinkage void __exception do_debug_exception(unsigned long addr_if_watchpoint,
 					       unsigned int esr,
 					       struct pt_regs *regs)
@@ -818,6 +848,9 @@ asmlinkage void __exception do_debug_exception(unsigned long addr_if_watchpoint,
 	const struct fault_info *inf = esr_to_debug_fault_info(esr);
 	unsigned long pc = instruction_pointer(regs);
 
+	if (cortex_a76_erratum_1463225_debug_handler(regs))
+		return;
+
 	/*
 	 * Tell lockdep we disabled irqs in entry.S. Do nothing if they were
 	 * already disabled to preserve the last enabled/disabled addresses.