Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 50b30ff..9fc6db0 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -1,23 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Based on arch/arm/mm/fault.c
*
* Copyright (C) 1995 Linus Torvalds
* Copyright (C) 1995-2004 Russell King
* Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/acpi.h>
+#include <linux/bitfield.h>
#include <linux/extable.h>
#include <linux/signal.h>
#include <linux/mm.h>
@@ -33,20 +24,21 @@
#include <linux/preempt.h>
#include <linux/hugetlb.h>
+#include <asm/acpi.h>
#include <asm/bug.h>
#include <asm/cmpxchg.h>
#include <asm/cpufeature.h>
#include <asm/exception.h>
+#include <asm/daifflags.h>
#include <asm/debug-monitors.h>
#include <asm/esr.h>
+#include <asm/kasan.h>
#include <asm/sysreg.h>
#include <asm/system_misc.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/traps.h>
-#include <acpi/ghes.h>
-
struct fault_info {
int (*fn)(unsigned long addr, unsigned int esr,
struct pt_regs *regs);
@@ -56,33 +48,17 @@
};
static const struct fault_info fault_info[];
+static struct fault_info debug_fault_info[];
static inline const struct fault_info *esr_to_fault_info(unsigned int esr)
{
- return fault_info + (esr & 63);
+ return fault_info + (esr & ESR_ELx_FSC);
}
-#ifdef CONFIG_KPROBES
-static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr)
+static inline const struct fault_info *esr_to_debug_fault_info(unsigned int esr)
{
- int ret = 0;
-
- /* kprobe_running() needs smp_processor_id() */
- if (!user_mode(regs)) {
- preempt_disable();
- if (kprobe_running() && kprobe_fault_handler(regs, esr))
- ret = 1;
- preempt_enable();
- }
-
- return ret;
+ return debug_fault_info + DBG_ESR_EVT(esr);
}
-#else
-static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr)
-{
- return 0;
-}
-#endif
static void data_abort_decode(unsigned int esr)
{
@@ -111,8 +87,8 @@
pr_alert("Mem abort info:\n");
pr_alert(" ESR = 0x%08x\n", esr);
- pr_alert(" Exception class = %s, IL = %u bits\n",
- esr_get_class_string(esr),
+ pr_alert(" EC = 0x%02lx: %s, IL = %u bits\n",
+ ESR_ELx_EC(esr), esr_get_class_string(esr),
(esr & ESR_ELx_IL) ? 32 : 16);
pr_alert(" SET = %lu, FnV = %lu\n",
(esr & ESR_ELx_SET_MASK) >> ESR_ELx_SET_SHIFT,
@@ -125,16 +101,37 @@
data_abort_decode(esr);
}
+static inline bool is_ttbr0_addr(unsigned long addr)
+{
+ /* entry assembly clears tags for TTBR0 addrs */
+ return addr < TASK_SIZE;
+}
+
+static inline bool is_ttbr1_addr(unsigned long addr)
+{
+ /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
+ return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
+}
+
+static inline unsigned long mm_to_pgd_phys(struct mm_struct *mm)
+{
+ /* Either init_pg_dir or swapper_pg_dir */
+ if (mm == &init_mm)
+ return __pa_symbol(mm->pgd);
+
+ return (unsigned long)virt_to_phys(mm->pgd);
+}
+
/*
* Dump out the page tables associated with 'addr' in the currently active mm.
*/
-void show_pte(unsigned long addr)
+static void show_pte(unsigned long addr)
{
struct mm_struct *mm;
pgd_t *pgdp;
pgd_t pgd;
- if (addr < TASK_SIZE) {
+ if (is_ttbr0_addr(addr)) {
/* TTBR0 */
mm = current->active_mm;
if (mm == &init_mm) {
@@ -142,7 +139,7 @@
addr);
return;
}
- } else if (addr >= VA_START) {
+ } else if (is_ttbr1_addr(addr)) {
/* TTBR1 */
mm = &init_mm;
} else {
@@ -151,9 +148,9 @@
return;
}
- pr_alert("%s pgtable: %luk pages, %u-bit VAs, pgdp = %p\n",
+ pr_alert("%s pgtable: %luk pages, %llu-bit VAs, pgdp=%016lx\n",
mm == &init_mm ? "swapper" : "user", PAGE_SIZE / SZ_1K,
- VA_BITS, mm->pgd);
+ vabits_actual, mm_to_pgd_phys(mm));
pgdp = pgd_offset(mm, addr);
pgd = READ_ONCE(*pgdp);
pr_alert("[%016lx] pgd=%016llx", addr, pgd_val(pgd));
@@ -235,9 +232,8 @@
return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_CUR;
}
-static inline bool is_el1_permission_fault(unsigned int esr,
- struct pt_regs *regs,
- unsigned long addr)
+static inline bool is_el1_permission_fault(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs)
{
unsigned int ec = ESR_ELx_EC(esr);
unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE;
@@ -248,13 +244,45 @@
if (fsc_type == ESR_ELx_FSC_PERM)
return true;
- if (addr < TASK_SIZE && system_uses_ttbr0_pan())
+ if (is_ttbr0_addr(addr) && system_uses_ttbr0_pan())
return fsc_type == ESR_ELx_FSC_FAULT &&
(regs->pstate & PSR_PAN_BIT);
return false;
}
+static bool __kprobes is_spurious_el1_translation_fault(unsigned long addr,
+ unsigned int esr,
+ struct pt_regs *regs)
+{
+ unsigned long flags;
+ u64 par, dfsc;
+
+ if (ESR_ELx_EC(esr) != ESR_ELx_EC_DABT_CUR ||
+ (esr & ESR_ELx_FSC_TYPE) != ESR_ELx_FSC_FAULT)
+ return false;
+
+ local_irq_save(flags);
+ asm volatile("at s1e1r, %0" :: "r" (addr));
+ isb();
+ par = read_sysreg(par_el1);
+ local_irq_restore(flags);
+
+ /*
+ * If we now have a valid translation, treat the translation fault as
+ * spurious.
+ */
+ if (!(par & SYS_PAR_EL1_F))
+ return true;
+
+ /*
+ * If we got a different type of fault from the AT instruction,
+ * treat the translation fault as spurious.
+ */
+ dfsc = FIELD_GET(SYS_PAR_EL1_FST, par);
+ return (dfsc & ESR_ELx_FSC_TYPE) != ESR_ELx_FSC_FAULT;
+}
+
static void die_kernel_fault(const char *msg, unsigned long addr,
unsigned int esr, struct pt_regs *regs)
{
@@ -283,7 +311,11 @@
if (!is_el1_instruction_abort(esr) && fixup_exception(regs))
return;
- if (is_el1_permission_fault(esr, regs, addr)) {
+ if (WARN_RATELIMIT(is_spurious_el1_translation_fault(addr, esr, regs),
+ "Ignoring spurious kernel translation fault at virtual address %016lx\n", addr))
+ return;
+
+ if (is_el1_permission_fault(addr, esr, regs)) {
if (esr & ESR_ELx_WNR)
msg = "write to read-only memory";
else
@@ -297,9 +329,9 @@
die_kernel_fault(msg, addr, esr, regs);
}
-static void __do_user_fault(struct siginfo *info, unsigned int esr)
+static void set_thread_esr(unsigned long address, unsigned int esr)
{
- current->thread.fault_address = (unsigned long)info->si_addr;
+ current->thread.fault_address = address;
/*
* If the faulting address is in the kernel, we must sanitize the ESR.
@@ -313,7 +345,7 @@
* type", so we ignore this wrinkle and just return the translation
* fault.)
*/
- if (current->thread.fault_address >= TASK_SIZE) {
+ if (!is_ttbr0_addr(current->thread.fault_address)) {
switch (ESR_ELx_EC(esr)) {
case ESR_ELx_EC_DABT_LOW:
/*
@@ -352,7 +384,6 @@
}
current->thread.fault_code = esr;
- arm64_force_sig_info(info, esr_to_fault_info(esr)->name, current);
}
static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
@@ -363,14 +394,10 @@
*/
if (user_mode(regs)) {
const struct fault_info *inf = esr_to_fault_info(esr);
- struct siginfo si;
- clear_siginfo(&si);
- si.si_signo = inf->sig;
- si.si_code = inf->code;
- si.si_addr = (void __user *)addr;
-
- __do_user_fault(&si, esr);
+ set_thread_esr(addr, esr);
+ arm64_force_sig_fault(inf->sig, inf->code, (void __user *)addr,
+ inf->name);
} else {
__do_kernel_fault(addr, esr, regs);
}
@@ -380,40 +407,31 @@
#define VM_FAULT_BADACCESS 0x020000
static vm_fault_t __do_page_fault(struct mm_struct *mm, unsigned long addr,
- unsigned int mm_flags, unsigned long vm_flags,
- struct task_struct *tsk)
+ unsigned int mm_flags, unsigned long vm_flags)
{
- struct vm_area_struct *vma;
- vm_fault_t fault;
+ struct vm_area_struct *vma = find_vma(mm, addr);
- vma = find_vma(mm, addr);
- fault = VM_FAULT_BADMAP;
if (unlikely(!vma))
- goto out;
- if (unlikely(vma->vm_start > addr))
- goto check_stack;
+ return VM_FAULT_BADMAP;
/*
* Ok, we have a good vm_area for this memory access, so we can handle
* it.
*/
-good_area:
+ if (unlikely(vma->vm_start > addr)) {
+ if (!(vma->vm_flags & VM_GROWSDOWN))
+ return VM_FAULT_BADMAP;
+ if (expand_stack(vma, addr))
+ return VM_FAULT_BADMAP;
+ }
+
/*
* Check that the permissions on the VMA allow for the fault which
* occurred.
*/
- if (!(vma->vm_flags & vm_flags)) {
- fault = VM_FAULT_BADACCESS;
- goto out;
- }
-
+ if (!(vma->vm_flags & vm_flags))
+ return VM_FAULT_BADACCESS;
return handle_mm_fault(vma, addr & PAGE_MASK, mm_flags);
-
-check_stack:
- if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
- goto good_area;
-out:
- return fault;
}
static bool is_el0_instruction_abort(unsigned int esr)
@@ -421,22 +439,27 @@
return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW;
}
+/*
+ * Note: not valid for EL1 DC IVAC, but we never use that such that it
+ * should fault. EL0 cannot issue DC IVAC (undef).
+ */
+static bool is_write_abort(unsigned int esr)
+{
+ return (esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM);
+}
+
static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
{
- struct task_struct *tsk;
- struct mm_struct *mm;
- struct siginfo si;
+ const struct fault_info *inf;
+ struct mm_struct *mm = current->mm;
vm_fault_t fault, major = 0;
unsigned long vm_flags = VM_READ | VM_WRITE;
unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
- if (notify_page_fault(regs, esr))
+ if (kprobe_page_fault(regs, esr))
return 0;
- tsk = current;
- mm = tsk->mm;
-
/*
* If we're in an interrupt or have no user context, we must not take
* the fault.
@@ -449,12 +472,13 @@
if (is_el0_instruction_abort(esr)) {
vm_flags = VM_EXEC;
- } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) {
+ mm_flags |= FAULT_FLAG_INSTRUCTION;
+ } else if (is_write_abort(esr)) {
vm_flags = VM_WRITE;
mm_flags |= FAULT_FLAG_WRITE;
}
- if (addr < TASK_SIZE && is_el1_permission_fault(esr, regs, addr)) {
+ if (is_ttbr0_addr(addr) && is_el1_permission_fault(addr, esr, regs)) {
/* regs->orig_addr_limit may be 0 if we entered from EL0 */
if (regs->orig_addr_limit == KERNEL_DS)
die_kernel_fault("access to user memory with fs=KERNEL_DS",
@@ -488,12 +512,14 @@
*/
might_sleep();
#ifdef CONFIG_DEBUG_VM
- if (!user_mode(regs) && !search_exception_tables(regs->pc))
+ if (!user_mode(regs) && !search_exception_tables(regs->pc)) {
+ up_read(&mm->mmap_sem);
goto no_context;
+ }
#endif
}
- fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk);
+ fault = __do_page_fault(mm, addr, mm_flags, vm_flags);
major |= fault & VM_FAULT_MAJOR;
if (fault & VM_FAULT_RETRY) {
@@ -533,11 +559,11 @@
* that point.
*/
if (major) {
- tsk->maj_flt++;
+ current->maj_flt++;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
addr);
} else {
- tsk->min_flt++;
+ current->min_flt++;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs,
addr);
}
@@ -562,37 +588,35 @@
return 0;
}
- clear_siginfo(&si);
- si.si_addr = (void __user *)addr;
-
+ inf = esr_to_fault_info(esr);
+ set_thread_esr(addr, esr);
if (fault & VM_FAULT_SIGBUS) {
/*
* We had some memory, but were unable to successfully fix up
* this page fault.
*/
- si.si_signo = SIGBUS;
- si.si_code = BUS_ADRERR;
- } else if (fault & VM_FAULT_HWPOISON_LARGE) {
- unsigned int hindex = VM_FAULT_GET_HINDEX(fault);
+ arm64_force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)addr,
+ inf->name);
+ } else if (fault & (VM_FAULT_HWPOISON_LARGE | VM_FAULT_HWPOISON)) {
+ unsigned int lsb;
- si.si_signo = SIGBUS;
- si.si_code = BUS_MCEERR_AR;
- si.si_addr_lsb = hstate_index_to_shift(hindex);
- } else if (fault & VM_FAULT_HWPOISON) {
- si.si_signo = SIGBUS;
- si.si_code = BUS_MCEERR_AR;
- si.si_addr_lsb = PAGE_SHIFT;
+ lsb = PAGE_SHIFT;
+ if (fault & VM_FAULT_HWPOISON_LARGE)
+ lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
+
+ arm64_force_sig_mceerr(BUS_MCEERR_AR, (void __user *)addr, lsb,
+ inf->name);
} else {
/*
* Something tried to access memory that isn't in our memory
* map.
*/
- si.si_signo = SIGSEGV;
- si.si_code = fault == VM_FAULT_BADACCESS ?
- SEGV_ACCERR : SEGV_MAPERR;
+ arm64_force_sig_fault(SIGSEGV,
+ fault == VM_FAULT_BADACCESS ? SEGV_ACCERR : SEGV_MAPERR,
+ (void __user *)addr,
+ inf->name);
}
- __do_user_fault(&si, esr);
return 0;
no_context:
@@ -604,7 +628,7 @@
unsigned int esr,
struct pt_regs *regs)
{
- if (addr < TASK_SIZE)
+ if (is_ttbr0_addr(addr))
return do_page_fault(addr, esr, regs);
do_bad_area(addr, esr, regs);
@@ -625,35 +649,22 @@
static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
{
- struct siginfo info;
const struct fault_info *inf;
+ void __user *siaddr;
inf = esr_to_fault_info(esr);
/*
- * Synchronous aborts may interrupt code which had interrupts masked.
- * Before calling out into the wider kernel tell the interested
- * subsystems.
+ * Return value ignored as we rely on signal merging.
+ * Future patches will make this more robust.
*/
- if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) {
- if (interrupts_enabled(regs))
- nmi_enter();
+ apei_claim_sea(regs);
- ghes_notify_sea();
-
- if (interrupts_enabled(regs))
- nmi_exit();
- }
-
- clear_siginfo(&info);
- info.si_signo = inf->sig;
- info.si_errno = 0;
- info.si_code = inf->code;
if (esr & ESR_ELx_FnV)
- info.si_addr = NULL;
+ siaddr = NULL;
else
- info.si_addr = (void __user *)addr;
- arm64_notify_die(inf->name, regs, &info, esr);
+ siaddr = (void __user *)addr;
+ arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr);
return 0;
}
@@ -725,16 +736,10 @@
{ do_bad, SIGKILL, SI_KERNEL, "unknown 63" },
};
-int handle_guest_sea(phys_addr_t addr, unsigned int esr)
-{
- return ghes_notify_sea();
-}
-
asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
{
const struct fault_info *inf = esr_to_fault_info(esr);
- struct siginfo info;
if (!inf->fn(addr, esr, regs))
return;
@@ -745,12 +750,8 @@
show_pte(addr);
}
- clear_siginfo(&info);
- info.si_signo = inf->sig;
- info.si_errno = 0;
- info.si_code = inf->code;
- info.si_addr = (void __user *)addr;
- arm64_notify_die(inf->name, regs, &info, esr);
+ arm64_notify_die(inf->name, regs,
+ inf->sig, inf->code, (void __user *)addr, esr);
}
asmlinkage void __exception do_el0_irq_bp_hardening(void)
@@ -768,10 +769,10 @@
* re-enabled IRQs. If the address is a kernel address, apply
* BP hardening prior to enabling IRQs and pre-emption.
*/
- if (addr > TASK_SIZE)
+ if (!is_ttbr0_addr(addr))
arm64_apply_bp_hardening();
- local_irq_enable();
+ local_daif_restore(DAIF_PROCCTX);
do_mem_abort(addr, esr, regs);
}
@@ -780,20 +781,14 @@
unsigned int esr,
struct pt_regs *regs)
{
- struct siginfo info;
-
if (user_mode(regs)) {
- if (instruction_pointer(regs) > TASK_SIZE)
+ if (!is_ttbr0_addr(instruction_pointer(regs)))
arm64_apply_bp_hardening();
- local_irq_enable();
+ local_daif_restore(DAIF_PROCCTX);
}
- clear_siginfo(&info);
- info.si_signo = SIGBUS;
- info.si_errno = 0;
- info.si_code = BUS_ADRALN;
- info.si_addr = (void __user *)addr;
- arm64_notify_die("SP/PC alignment exception", regs, &info, esr);
+ arm64_notify_die("SP/PC alignment exception", regs,
+ SIGBUS, BUS_ADRALN, (void __user *)addr, esr);
}
int __init early_brk64(unsigned long addr, unsigned int esr,
@@ -827,13 +822,15 @@
debug_fault_info[nr].name = name;
}
-asmlinkage int __exception do_debug_exception(unsigned long addr,
- unsigned int esr,
- struct pt_regs *regs)
+/*
+ * In debug exception context, we explicitly disable preemption despite
+ * having interrupts disabled.
+ * This serves two purposes: it makes it much less likely that we would
+ * accidentally schedule in exception context and it will force a warning
+ * if we somehow manage to schedule by accident.
+ */
+static void debug_exception_enter(struct pt_regs *regs)
{
- const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr);
- int rv;
-
/*
* Tell lockdep we disabled irqs in entry.S. Do nothing if they were
* already disabled to preserve the last enabled/disabled addresses.
@@ -841,40 +838,87 @@
if (interrupts_enabled(regs))
trace_hardirqs_off();
- if (user_mode(regs) && instruction_pointer(regs) > TASK_SIZE)
- arm64_apply_bp_hardening();
-
- if (!inf->fn(addr, esr, regs)) {
- rv = 1;
+ if (user_mode(regs)) {
+ RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
} else {
- struct siginfo info;
-
- clear_siginfo(&info);
- info.si_signo = inf->sig;
- info.si_errno = 0;
- info.si_code = inf->code;
- info.si_addr = (void __user *)addr;
- arm64_notify_die(inf->name, regs, &info, esr);
- rv = 0;
+ /*
+ * We might have interrupted pretty much anything. In
+ * fact, if we're a debug exception, we can even interrupt
+ * NMI processing. We don't want this code makes in_nmi()
+ * to return true, but we need to notify RCU.
+ */
+ rcu_nmi_enter();
}
+ preempt_disable();
+
+ /* This code is a bit fragile. Test it. */
+ RCU_LOCKDEP_WARN(!rcu_is_watching(), "exception_enter didn't work");
+}
+NOKPROBE_SYMBOL(debug_exception_enter);
+
+static void debug_exception_exit(struct pt_regs *regs)
+{
+ preempt_enable_no_resched();
+
+ if (!user_mode(regs))
+ rcu_nmi_exit();
+
if (interrupts_enabled(regs))
trace_hardirqs_on();
+}
+NOKPROBE_SYMBOL(debug_exception_exit);
- return rv;
+#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)
+{
+ 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;
+
+ debug_exception_enter(regs);
+
+ if (user_mode(regs) && !is_ttbr0_addr(pc))
+ arm64_apply_bp_hardening();
+
+ if (inf->fn(addr_if_watchpoint, esr, regs)) {
+ arm64_notify_die(inf->name, regs,
+ inf->sig, inf->code, (void __user *)pc, esr);
+ }
+
+ debug_exception_exit(regs);
}
NOKPROBE_SYMBOL(do_debug_exception);
-
-#ifdef CONFIG_ARM64_PAN
-void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
-{
- /*
- * We modify PSTATE. This won't work from irq context as the PSTATE
- * is discarded once we return from the exception.
- */
- WARN_ON_ONCE(in_interrupt());
-
- sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
- asm(SET_PSTATE_PAN(1));
-}
-#endif /* CONFIG_ARM64_PAN */