diff options
author | Catalin Marinas <catalin.marinas@arm.com> | 2022-09-30 09:18:26 +0100 |
---|---|---|
committer | Catalin Marinas <catalin.marinas@arm.com> | 2022-09-30 09:18:26 +0100 |
commit | 53630a1f6186e9df5fb75e9b55328e22b64de150 (patch) | |
tree | cce45ad34594ae21ee6b2f7b37e6aadfc00715ec /arch/arm64/kernel | |
parent | c704cf27a1adc5fa40fb8e40b5617bdca889a419 (diff) | |
parent | a0caebbd04602cb7d28f6f316213a915ffab92a2 (diff) |
Merge branch 'for-next/misc' into for-next/core
* for-next/misc:
: Miscellaneous patches
arm64/kprobe: Optimize the performance of patching single-step slot
ARM64: reloc_test: add __init/__exit annotations to module init/exit funcs
arm64/mm: fold check for KFENCE into can_set_direct_map()
arm64: uaccess: simplify uaccess_mask_ptr()
arm64: mte: move register initialization to C
arm64: mm: handle ARM64_KERNEL_USES_PMD_MAPS in vmemmap_populate()
arm64: dma: Drop cache invalidation from arch_dma_prep_coherent()
arm64: support huge vmalloc mappings
arm64: spectre: increase parameters that can be used to turn off bhb mitigation individually
arm64: run softirqs on the per-CPU IRQ stack
arm64: compat: Implement misalignment fixups for multiword loads
Diffstat (limited to 'arch/arm64/kernel')
-rw-r--r-- | arch/arm64/kernel/Makefile | 1 | ||||
-rw-r--r-- | arch/arm64/kernel/compat_alignment.c | 387 | ||||
-rw-r--r-- | arch/arm64/kernel/cpufeature.c | 3 | ||||
-rw-r--r-- | arch/arm64/kernel/irq.c | 14 | ||||
-rw-r--r-- | arch/arm64/kernel/mte.c | 51 | ||||
-rw-r--r-- | arch/arm64/kernel/probes/kprobes.c | 27 | ||||
-rw-r--r-- | arch/arm64/kernel/proton-pack.c | 10 | ||||
-rw-r--r-- | arch/arm64/kernel/reloc_test_core.c | 4 | ||||
-rw-r--r-- | arch/arm64/kernel/suspend.c | 2 |
9 files changed, 489 insertions, 10 deletions
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 1add7b01efa7..38a0b0291edb 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -45,6 +45,7 @@ $(obj)/%.stub.o: $(obj)/%.o FORCE obj-$(CONFIG_COMPAT) += sys32.o signal32.o \ sys_compat.o obj-$(CONFIG_COMPAT) += sigreturn32.o +obj-$(CONFIG_COMPAT_ALIGNMENT_FIXUPS) += compat_alignment.o obj-$(CONFIG_KUSER_HELPERS) += kuser32.o obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o obj-$(CONFIG_MODULES) += module.o diff --git a/arch/arm64/kernel/compat_alignment.c b/arch/arm64/kernel/compat_alignment.c new file mode 100644 index 000000000000..5edec2f49ec9 --- /dev/null +++ b/arch/arm64/kernel/compat_alignment.c @@ -0,0 +1,387 @@ +// SPDX-License-Identifier: GPL-2.0-only +// based on arch/arm/mm/alignment.c + +#include <linux/compiler.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/perf_event.h> +#include <linux/uaccess.h> + +#include <asm/exception.h> +#include <asm/ptrace.h> +#include <asm/traps.h> + +/* + * 32-bit misaligned trap handler (c) 1998 San Mehat (CCC) -July 1998 + * + * Speed optimisations and better fault handling by Russell King. + */ +#define CODING_BITS(i) (i & 0x0e000000) + +#define LDST_P_BIT(i) (i & (1 << 24)) /* Preindex */ +#define LDST_U_BIT(i) (i & (1 << 23)) /* Add offset */ +#define LDST_W_BIT(i) (i & (1 << 21)) /* Writeback */ +#define LDST_L_BIT(i) (i & (1 << 20)) /* Load */ + +#define LDST_P_EQ_U(i) ((((i) ^ ((i) >> 1)) & (1 << 23)) == 0) + +#define LDSTHD_I_BIT(i) (i & (1 << 22)) /* double/half-word immed */ + +#define RN_BITS(i) ((i >> 16) & 15) /* Rn */ +#define RD_BITS(i) ((i >> 12) & 15) /* Rd */ +#define RM_BITS(i) (i & 15) /* Rm */ + +#define REGMASK_BITS(i) (i & 0xffff) + +#define BAD_INSTR 0xdeadc0de + +/* Thumb-2 32 bit format per ARMv7 DDI0406A A6.3, either f800h,e800h,f800h */ +#define IS_T32(hi16) \ + (((hi16) & 0xe000) == 0xe000 && ((hi16) & 0x1800)) + +union offset_union { + unsigned long un; + signed long sn; +}; + +#define TYPE_ERROR 0 +#define TYPE_FAULT 1 +#define TYPE_LDST 2 +#define TYPE_DONE 3 + +static void +do_alignment_finish_ldst(unsigned long addr, u32 instr, struct pt_regs *regs, + union offset_union offset) +{ + if (!LDST_U_BIT(instr)) + offset.un = -offset.un; + + if (!LDST_P_BIT(instr)) + addr += offset.un; + + if (!LDST_P_BIT(instr) || LDST_W_BIT(instr)) + regs->regs[RN_BITS(instr)] = addr; +} + +static int +do_alignment_ldrdstrd(unsigned long addr, u32 instr, struct pt_regs *regs) +{ + unsigned int rd = RD_BITS(instr); + unsigned int rd2; + int load; + + if ((instr & 0xfe000000) == 0xe8000000) { + /* ARMv7 Thumb-2 32-bit LDRD/STRD */ + rd2 = (instr >> 8) & 0xf; + load = !!(LDST_L_BIT(instr)); + } else if (((rd & 1) == 1) || (rd == 14)) { + return TYPE_ERROR; + } else { + load = ((instr & 0xf0) == 0xd0); + rd2 = rd + 1; + } + + if (load) { + unsigned int val, val2; + + if (get_user(val, (u32 __user *)addr) || + get_user(val2, (u32 __user *)(addr + 4))) + return TYPE_FAULT; + regs->regs[rd] = val; + regs->regs[rd2] = val2; + } else { + if (put_user(regs->regs[rd], (u32 __user *)addr) || + put_user(regs->regs[rd2], (u32 __user *)(addr + 4))) + return TYPE_FAULT; + } + return TYPE_LDST; +} + +/* + * LDM/STM alignment handler. + * + * There are 4 variants of this instruction: + * + * B = rn pointer before instruction, A = rn pointer after instruction + * ------ increasing address -----> + * | | r0 | r1 | ... | rx | | + * PU = 01 B A + * PU = 11 B A + * PU = 00 A B + * PU = 10 A B + */ +static int +do_alignment_ldmstm(unsigned long addr, u32 instr, struct pt_regs *regs) +{ + unsigned int rd, rn, nr_regs, regbits; + unsigned long eaddr, newaddr; + unsigned int val; + + /* count the number of registers in the mask to be transferred */ + nr_regs = hweight16(REGMASK_BITS(instr)) * 4; + + rn = RN_BITS(instr); + newaddr = eaddr = regs->regs[rn]; + + if (!LDST_U_BIT(instr)) + nr_regs = -nr_regs; + newaddr += nr_regs; + if (!LDST_U_BIT(instr)) + eaddr = newaddr; + + if (LDST_P_EQ_U(instr)) /* U = P */ + eaddr += 4; + + for (regbits = REGMASK_BITS(instr), rd = 0; regbits; + regbits >>= 1, rd += 1) + if (regbits & 1) { + if (LDST_L_BIT(instr)) { + if (get_user(val, (u32 __user *)eaddr)) + return TYPE_FAULT; + if (rd < 15) + regs->regs[rd] = val; + else + regs->pc = val; + } else { + /* + * The PC register has a bias of +8 in ARM mode + * and +4 in Thumb mode. This means that a read + * of the value of PC should account for this. + * Since Thumb does not permit STM instructions + * to refer to PC, just add 8 here. + */ + val = (rd < 15) ? regs->regs[rd] : regs->pc + 8; + if (put_user(val, (u32 __user *)eaddr)) + return TYPE_FAULT; + } + eaddr += 4; + } + + if (LDST_W_BIT(instr)) + regs->regs[rn] = newaddr; + + return TYPE_DONE; +} + +/* + * Convert Thumb multi-word load/store instruction forms to equivalent ARM + * instructions so we can reuse ARM userland alignment fault fixups for Thumb. + * + * This implementation was initially based on the algorithm found in + * gdb/sim/arm/thumbemu.c. It is basically just a code reduction of same + * to convert only Thumb ld/st instruction forms to equivalent ARM forms. + * + * NOTES: + * 1. Comments below refer to ARM ARM DDI0100E Thumb Instruction sections. + * 2. If for some reason we're passed an non-ld/st Thumb instruction to + * decode, we return 0xdeadc0de. This should never happen under normal + * circumstances but if it does, we've got other problems to deal with + * elsewhere and we obviously can't fix those problems here. + */ + +static unsigned long thumb2arm(u16 tinstr) +{ + u32 L = (tinstr & (1<<11)) >> 11; + + switch ((tinstr & 0xf800) >> 11) { + /* 6.6.1 Format 1: */ + case 0xc000 >> 11: /* 7.1.51 STMIA */ + case 0xc800 >> 11: /* 7.1.25 LDMIA */ + { + u32 Rn = (tinstr & (7<<8)) >> 8; + u32 W = ((L<<Rn) & (tinstr&255)) ? 0 : 1<<21; + + return 0xe8800000 | W | (L<<20) | (Rn<<16) | + (tinstr&255); + } + + /* 6.6.1 Format 2: */ + case 0xb000 >> 11: /* 7.1.48 PUSH */ + case 0xb800 >> 11: /* 7.1.47 POP */ + if ((tinstr & (3 << 9)) == 0x0400) { + static const u32 subset[4] = { + 0xe92d0000, /* STMDB sp!,{registers} */ + 0xe92d4000, /* STMDB sp!,{registers,lr} */ + 0xe8bd0000, /* LDMIA sp!,{registers} */ + 0xe8bd8000 /* LDMIA sp!,{registers,pc} */ + }; + return subset[(L<<1) | ((tinstr & (1<<8)) >> 8)] | + (tinstr & 255); /* register_list */ + } + fallthrough; /* for illegal instruction case */ + + default: + return BAD_INSTR; + } +} + +/* + * Convert Thumb-2 32 bit LDM, STM, LDRD, STRD to equivalent instruction + * handlable by ARM alignment handler, also find the corresponding handler, + * so that we can reuse ARM userland alignment fault fixups for Thumb. + * + * @pinstr: original Thumb-2 instruction; returns new handlable instruction + * @regs: register context. + * @poffset: return offset from faulted addr for later writeback + * + * NOTES: + * 1. Comments below refer to ARMv7 DDI0406A Thumb Instruction sections. + * 2. Register name Rt from ARMv7 is same as Rd from ARMv6 (Rd is Rt) + */ +static void * +do_alignment_t32_to_handler(u32 *pinstr, struct pt_regs *regs, + union offset_union *poffset) +{ + u32 instr = *pinstr; + u16 tinst1 = (instr >> 16) & 0xffff; + u16 tinst2 = instr & 0xffff; + + switch (tinst1 & 0xffe0) { + /* A6.3.5 Load/Store multiple */ + case 0xe880: /* STM/STMIA/STMEA,LDM/LDMIA, PUSH/POP T2 */ + case 0xe8a0: /* ...above writeback version */ + case 0xe900: /* STMDB/STMFD, LDMDB/LDMEA */ + case 0xe920: /* ...above writeback version */ + /* no need offset decision since handler calculates it */ + return do_alignment_ldmstm; + + case 0xf840: /* POP/PUSH T3 (single register) */ + if (RN_BITS(instr) == 13 && (tinst2 & 0x09ff) == 0x0904) { + u32 L = !!(LDST_L_BIT(instr)); + const u32 subset[2] = { + 0xe92d0000, /* STMDB sp!,{registers} */ + 0xe8bd0000, /* LDMIA sp!,{registers} */ + }; + *pinstr = subset[L] | (1<<RD_BITS(instr)); + return do_alignment_ldmstm; + } + /* Else fall through for illegal instruction case */ + break; + + /* A6.3.6 Load/store double, STRD/LDRD(immed, lit, reg) */ + case 0xe860: + case 0xe960: + case 0xe8e0: + case 0xe9e0: + poffset->un = (tinst2 & 0xff) << 2; + fallthrough; + + case 0xe940: + case 0xe9c0: + return do_alignment_ldrdstrd; + + /* + * No need to handle load/store instructions up to word size + * since ARMv6 and later CPUs can perform unaligned accesses. + */ + default: + break; + } + return NULL; +} + +static int alignment_get_arm(struct pt_regs *regs, __le32 __user *ip, u32 *inst) +{ + __le32 instr = 0; + int fault; + + fault = get_user(instr, ip); + if (fault) + return fault; + + *inst = __le32_to_cpu(instr); + return 0; +} + +static int alignment_get_thumb(struct pt_regs *regs, __le16 __user *ip, u16 *inst) +{ + __le16 instr = 0; + int fault; + + fault = get_user(instr, ip); + if (fault) + return fault; + + *inst = __le16_to_cpu(instr); + return 0; +} + +int do_compat_alignment_fixup(unsigned long addr, struct pt_regs *regs) +{ + union offset_union offset; + unsigned long instrptr; + int (*handler)(unsigned long addr, u32 instr, struct pt_regs *regs); + unsigned int type; + u32 instr = 0; + u16 tinstr = 0; + int isize = 4; + int thumb2_32b = 0; + int fault; + + instrptr = instruction_pointer(regs); + + if (compat_thumb_mode(regs)) { + __le16 __user *ptr = (__le16 __user *)(instrptr & ~1); + + fault = alignment_get_thumb(regs, ptr, &tinstr); + if (!fault) { + if (IS_T32(tinstr)) { + /* Thumb-2 32-bit */ + u16 tinst2; + fault = alignment_get_thumb(regs, ptr + 1, &tinst2); + instr = ((u32)tinstr << 16) | tinst2; + thumb2_32b = 1; + } else { + isize = 2; + instr = thumb2arm(tinstr); + } + } + } else { + fault = alignment_get_arm(regs, (__le32 __user *)instrptr, &instr); + } + + if (fault) + return 1; + + switch (CODING_BITS(instr)) { + case 0x00000000: /* 3.13.4 load/store instruction extensions */ + if (LDSTHD_I_BIT(instr)) + offset.un = (instr & 0xf00) >> 4 | (instr & 15); + else + offset.un = regs->regs[RM_BITS(instr)]; + + if ((instr & 0x001000f0) == 0x000000d0 || /* LDRD */ + (instr & 0x001000f0) == 0x000000f0) /* STRD */ + handler = do_alignment_ldrdstrd; + else + return 1; + break; + + case 0x08000000: /* ldm or stm, or thumb-2 32bit instruction */ + if (thumb2_32b) { + offset.un = 0; + handler = do_alignment_t32_to_handler(&instr, regs, &offset); + } else { + offset.un = 0; + handler = do_alignment_ldmstm; + } + break; + + default: + return 1; + } + + type = handler(addr, instr, regs); + + if (type == TYPE_ERROR || type == TYPE_FAULT) + return 1; + + if (type == TYPE_LDST) + do_alignment_finish_ldst(addr, instr, regs, offset); + + perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, regs->pc); + arm64_skip_faulting_instruction(regs, isize); + + return 0; +} diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 5d0527ba0804..a51edf3c0214 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2043,7 +2043,8 @@ static void bti_enable(const struct arm64_cpu_capabilities *__unused) static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap) { sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_ATA | SCTLR_EL1_ATA0); - isb(); + + mte_cpu_setup(); /* * Clear the tags in the zero page. This needs to be done via the diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c index bda49430c9ea..38dbd3828f13 100644 --- a/arch/arm64/kernel/irq.c +++ b/arch/arm64/kernel/irq.c @@ -21,7 +21,9 @@ #include <linux/seq_file.h> #include <linux/vmalloc.h> #include <asm/daifflags.h> +#include <asm/exception.h> #include <asm/vmap_stack.h> +#include <asm/softirq_stack.h> /* Only access this in an NMI enter/exit */ DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts); @@ -71,6 +73,18 @@ static void init_irq_stacks(void) } #endif +#ifndef CONFIG_PREEMPT_RT +static void ____do_softirq(struct pt_regs *regs) +{ + __do_softirq(); +} + +void do_softirq_own_stack(void) +{ + call_on_irq_stack(NULL, ____do_softirq); +} +#endif + static void default_handle_irq(struct pt_regs *regs) { panic("IRQ taken without a root IRQ handler\n"); diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index b2b730233274..aca88470fb69 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -285,6 +285,49 @@ void mte_thread_switch(struct task_struct *next) mte_check_tfsr_el1(); } +void mte_cpu_setup(void) +{ + u64 rgsr; + + /* + * CnP must be enabled only after the MAIR_EL1 register has been set + * up. Inconsistent MAIR_EL1 between CPUs sharing the same TLB may + * lead to the wrong memory type being used for a brief window during + * CPU power-up. + * + * CnP is not a boot feature so MTE gets enabled before CnP, but let's + * make sure that is the case. + */ + BUG_ON(read_sysreg(ttbr0_el1) & TTBR_CNP_BIT); + BUG_ON(read_sysreg(ttbr1_el1) & TTBR_CNP_BIT); + + /* Normal Tagged memory type at the corresponding MAIR index */ + sysreg_clear_set(mair_el1, + MAIR_ATTRIDX(MAIR_ATTR_MASK, MT_NORMAL_TAGGED), + MAIR_ATTRIDX(MAIR_ATTR_NORMAL_TAGGED, + MT_NORMAL_TAGGED)); + + write_sysreg_s(KERNEL_GCR_EL1, SYS_GCR_EL1); + + /* + * If GCR_EL1.RRND=1 is implemented the same way as RRND=0, then + * RGSR_EL1.SEED must be non-zero for IRG to produce + * pseudorandom numbers. As RGSR_EL1 is UNKNOWN out of reset, we + * must initialize it. + */ + rgsr = (read_sysreg(CNTVCT_EL0) & SYS_RGSR_EL1_SEED_MASK) << + SYS_RGSR_EL1_SEED_SHIFT; + if (rgsr == 0) + rgsr = 1 << SYS_RGSR_EL1_SEED_SHIFT; + write_sysreg_s(rgsr, SYS_RGSR_EL1); + + /* clear any pending tag check faults in TFSR*_EL1 */ + write_sysreg_s(0, SYS_TFSR_EL1); + write_sysreg_s(0, SYS_TFSRE0_EL1); + + local_flush_tlb_all(); +} + void mte_suspend_enter(void) { if (!system_supports_mte()) @@ -301,6 +344,14 @@ void mte_suspend_enter(void) mte_check_tfsr_el1(); } +void mte_suspend_exit(void) +{ + if (!system_supports_mte()) + return; + + mte_cpu_setup(); +} + long set_mte_ctrl(struct task_struct *task, unsigned long arg) { u64 mte_ctrl = (~((arg & PR_MTE_TAG_MASK) >> PR_MTE_TAG_SHIFT) & diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index d1d182320245..c9e4d0720285 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -44,13 +44,28 @@ post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *); static void __kprobes arch_prepare_ss_slot(struct kprobe *p) { kprobe_opcode_t *addr = p->ainsn.api.insn; - void *addrs[] = {addr, addr + 1}; - u32 insns[] = {p->opcode, BRK64_OPCODE_KPROBES_SS}; - /* prepare insn slot */ - aarch64_insn_patch_text(addrs, insns, 2); - - flush_icache_range((uintptr_t)addr, (uintptr_t)(addr + MAX_INSN_SIZE)); + /* + * Prepare insn slot, Mark Rutland points out it depends on a coupe of + * subtleties: + * + * - That the I-cache maintenance for these instructions is complete + * *before* the kprobe BRK is written (and aarch64_insn_patch_text_nosync() + * ensures this, but just omits causing a Context-Synchronization-Event + * on all CPUS). + * + * - That the kprobe BRK results in an exception (and consequently a + * Context-Synchronoization-Event), which ensures that the CPU will + * fetch thesingle-step slot instructions *after* this, ensuring that + * the new instructions are used + * + * It supposes to place ISB after patching to guarantee I-cache maintenance + * is observed on all CPUS, however, single-step slot is installed in + * the BRK exception handler, so it is unnecessary to generate + * Contex-Synchronization-Event via ISB again. + */ + aarch64_insn_patch_text_nosync(addr, p->opcode); + aarch64_insn_patch_text_nosync(addr + 1, BRK64_OPCODE_KPROBES_SS); /* * Needs restoring of return address after stepping xol. diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c index ea659a382e24..a8ea1637b137 100644 --- a/arch/arm64/kernel/proton-pack.c +++ b/arch/arm64/kernel/proton-pack.c @@ -988,6 +988,14 @@ static void this_cpu_set_vectors(enum arm64_bp_harden_el1_vectors slot) isb(); } +static bool __read_mostly __nospectre_bhb; +static int __init parse_spectre_bhb_param(char *str) +{ + __nospectre_bhb = true; + return 0; +} +early_param("nospectre_bhb", parse_spectre_bhb_param); + void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry) { bp_hardening_cb_t cpu_cb; @@ -1001,7 +1009,7 @@ void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry) /* No point mitigating Spectre-BHB alone. */ } else if (!IS_ENABLED(CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY)) { pr_info_once("spectre-bhb mitigation disabled by compile time option\n"); - } else if (cpu_mitigations_off()) { + } else if (cpu_mitigations_off() || __nospectre_bhb) { pr_info_once("spectre-bhb mitigation disabled by command line option\n"); } else if (supports_ecbhb(SCOPE_LOCAL_CPU)) { state = SPECTRE_MITIGATED; diff --git a/arch/arm64/kernel/reloc_test_core.c b/arch/arm64/kernel/reloc_test_core.c index e87a2b7f20f6..99f2ffe9fc05 100644 --- a/arch/arm64/kernel/reloc_test_core.c +++ b/arch/arm64/kernel/reloc_test_core.c @@ -48,7 +48,7 @@ static struct { { "R_AARCH64_PREL16", relative_data16, (u64)&sym64_rel }, }; -static int reloc_test_init(void) +static int __init reloc_test_init(void) { int i; @@ -67,7 +67,7 @@ static int reloc_test_init(void) return 0; } -static void reloc_test_exit(void) +static void __exit reloc_test_exit(void) { } diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index 9135fe0f3df5..8b02d310838f 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -43,6 +43,8 @@ void notrace __cpu_suspend_exit(void) { unsigned int cpu = smp_processor_id(); + mte_suspend_exit(); + /* * We are resuming from reset with the idmap active in TTBR0_EL1. * We must uninstall the idmap and restore the expected MMU |