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authorWill Deacon <will@kernel.org>2021-06-24 14:01:55 +0100
committerWill Deacon <will@kernel.org>2021-06-24 14:01:55 +0100
commit6cf61e061e8e3d9c00fb49373196ed5f03235285 (patch)
tree438316bf5528be095e7c7215471ad53c6dc766dc
parentaeb3e82e432350234cd6803daf3057832d5e1178 (diff)
parentb5df5b8307b1db6d168ffac29eff3974779bb34b (diff)
Merge branch 'for-next/entry' into for-next/core
The never-ending entry.S refactoring continues, putting us in a much better place wrt compiler instrumentation whilst moving more of the code into C. * for-next/entry: arm64: idle: don't instrument idle code with KCOV arm64: entry: don't instrument entry code with KCOV arm64: entry: make NMI entry/exit functions static arm64: entry: split SDEI entry arm64: entry: split bad stack entry arm64: entry: fold el1_inv() into el1h_64_sync_handler() arm64: entry: handle all vectors with C arm64: entry: template the entry asm functions arm64: entry: improve bad_mode() arm64: entry: move bad_mode() to entry-common.c arm64: entry: consolidate EL1 exception returns arm64: entry: organise entry vectors consistently arm64: entry: organise entry handlers consistently arm64: entry: convert IRQ+FIQ handlers to C arm64: entry: add a call_on_irq_stack helper arm64: entry: move NMI preempt logic to C arm64: entry: move arm64_preempt_schedule_irq to entry-common.c arm64: entry: convert SError handlers to C arm64: entry: unmask IRQ+FIQ after EL0 handling arm64: remove redundant local_daif_mask() in bad_mode()
-rw-r--r--arch/arm64/include/asm/exception.h34
-rw-r--r--arch/arm64/include/asm/processor.h2
-rw-r--r--arch/arm64/include/asm/sdei.h3
-rw-r--r--arch/arm64/kernel/Makefile8
-rw-r--r--arch/arm64/kernel/entry-common.c256
-rw-r--r--arch/arm64/kernel/entry.S359
-rw-r--r--arch/arm64/kernel/idle.c46
-rw-r--r--arch/arm64/kernel/process.c52
-rw-r--r--arch/arm64/kernel/sdei.c48
-rw-r--r--arch/arm64/kernel/traps.c40
-rw-r--r--arch/arm64/mm/fault.c7
11 files changed, 417 insertions, 438 deletions
diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h
index 6546158d2f2d..4afbc45b8bb0 100644
--- a/arch/arm64/include/asm/exception.h
+++ b/arch/arm64/include/asm/exception.h
@@ -31,20 +31,35 @@ static inline u32 disr_to_esr(u64 disr)
return esr;
}
-asmlinkage void el1_sync_handler(struct pt_regs *regs);
-asmlinkage void el0_sync_handler(struct pt_regs *regs);
-asmlinkage void el0_sync_compat_handler(struct pt_regs *regs);
+asmlinkage void handle_bad_stack(struct pt_regs *regs);
-asmlinkage void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs);
-asmlinkage void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs);
+asmlinkage void el1t_64_sync_handler(struct pt_regs *regs);
+asmlinkage void el1t_64_irq_handler(struct pt_regs *regs);
+asmlinkage void el1t_64_fiq_handler(struct pt_regs *regs);
+asmlinkage void el1t_64_error_handler(struct pt_regs *regs);
+
+asmlinkage void el1h_64_sync_handler(struct pt_regs *regs);
+asmlinkage void el1h_64_irq_handler(struct pt_regs *regs);
+asmlinkage void el1h_64_fiq_handler(struct pt_regs *regs);
+asmlinkage void el1h_64_error_handler(struct pt_regs *regs);
+
+asmlinkage void el0t_64_sync_handler(struct pt_regs *regs);
+asmlinkage void el0t_64_irq_handler(struct pt_regs *regs);
+asmlinkage void el0t_64_fiq_handler(struct pt_regs *regs);
+asmlinkage void el0t_64_error_handler(struct pt_regs *regs);
+
+asmlinkage void el0t_32_sync_handler(struct pt_regs *regs);
+asmlinkage void el0t_32_irq_handler(struct pt_regs *regs);
+asmlinkage void el0t_32_fiq_handler(struct pt_regs *regs);
+asmlinkage void el0t_32_error_handler(struct pt_regs *regs);
+
+asmlinkage void call_on_irq_stack(struct pt_regs *regs,
+ void (*func)(struct pt_regs *));
asmlinkage void enter_from_user_mode(void);
asmlinkage void exit_to_user_mode(void);
-void arm64_enter_nmi(struct pt_regs *regs);
-void arm64_exit_nmi(struct pt_regs *regs);
void do_mem_abort(unsigned long far, unsigned int esr, struct pt_regs *regs);
void do_undefinstr(struct pt_regs *regs);
void do_bti(struct pt_regs *regs);
-asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr);
void do_debug_exception(unsigned long addr_if_watchpoint, unsigned int esr,
struct pt_regs *regs);
void do_fpsimd_acc(unsigned int esr, struct pt_regs *regs);
@@ -57,4 +72,7 @@ void do_cp15instr(unsigned int esr, struct pt_regs *regs);
void do_el0_svc(struct pt_regs *regs);
void do_el0_svc_compat(struct pt_regs *regs);
void do_ptrauth_fault(struct pt_regs *regs, unsigned int esr);
+void do_serror(struct pt_regs *regs, unsigned int esr);
+
+void panic_bad_stack(struct pt_regs *regs, unsigned int esr, unsigned long far);
#endif /* __ASM_EXCEPTION_H */
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index 7a094aafec20..7dba1c421b5b 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -257,8 +257,6 @@ void set_task_sctlr_el1(u64 sctlr);
extern struct task_struct *cpu_switch_to(struct task_struct *prev,
struct task_struct *next);
-asmlinkage void arm64_preempt_schedule_irq(void);
-
#define task_pt_regs(p) \
((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
diff --git a/arch/arm64/include/asm/sdei.h b/arch/arm64/include/asm/sdei.h
index 8bc30a5c4569..7bea1d705dd6 100644
--- a/arch/arm64/include/asm/sdei.h
+++ b/arch/arm64/include/asm/sdei.h
@@ -37,6 +37,9 @@ struct sdei_registered_event;
asmlinkage unsigned long __sdei_handler(struct pt_regs *regs,
struct sdei_registered_event *arg);
+unsigned long do_sdei_event(struct pt_regs *regs,
+ struct sdei_registered_event *arg);
+
unsigned long sdei_arch_get_entry_point(int conduit);
#define sdei_arch_get_entry_point(x) sdei_arch_get_entry_point(x)
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 6cc97730790e..de434204d723 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -14,6 +14,12 @@ CFLAGS_REMOVE_return_address.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_syscall.o = -fstack-protector -fstack-protector-strong
CFLAGS_syscall.o += -fno-stack-protector
+# It's not safe to invoke KCOV when portions of the kernel environment aren't
+# available or are out-of-sync with HW state. Since `noinstr` doesn't always
+# inhibit KCOV instrumentation, disable it for the entire compilation unit.
+KCOV_INSTRUMENT_entry.o := n
+KCOV_INSTRUMENT_idle.o := n
+
# Object file lists.
obj-y := debug-monitors.o entry.o irq.o fpsimd.o \
entry-common.o entry-fpsimd.o process.o ptrace.o \
@@ -22,7 +28,7 @@ obj-y := debug-monitors.o entry.o irq.o fpsimd.o \
return_address.o cpuinfo.o cpu_errata.o \
cpufeature.o alternative.o cacheinfo.o \
smp.o smp_spin_table.o topology.o smccc-call.o \
- syscall.o proton-pack.o idreg-override.o
+ syscall.o proton-pack.o idreg-override.o idle.o
targets += efi-entry.o
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index 340d04e13617..12ce14a98b7c 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -6,7 +6,11 @@
*/
#include <linux/context_tracking.h>
+#include <linux/linkage.h>
+#include <linux/lockdep.h>
#include <linux/ptrace.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
#include <linux/thread_info.h>
#include <asm/cpufeature.h>
@@ -15,7 +19,11 @@
#include <asm/exception.h>
#include <asm/kprobes.h>
#include <asm/mmu.h>
+#include <asm/processor.h>
+#include <asm/sdei.h>
+#include <asm/stacktrace.h>
#include <asm/sysreg.h>
+#include <asm/system_misc.h>
/*
* This is intended to match the logic in irqentry_enter(), handling the kernel
@@ -67,7 +75,7 @@ static void noinstr exit_to_kernel_mode(struct pt_regs *regs)
}
}
-void noinstr arm64_enter_nmi(struct pt_regs *regs)
+static void noinstr arm64_enter_nmi(struct pt_regs *regs)
{
regs->lockdep_hardirqs = lockdep_hardirqs_enabled();
@@ -80,7 +88,7 @@ void noinstr arm64_enter_nmi(struct pt_regs *regs)
ftrace_nmi_enter();
}
-void noinstr arm64_exit_nmi(struct pt_regs *regs)
+static void noinstr arm64_exit_nmi(struct pt_regs *regs)
{
bool restore = regs->lockdep_hardirqs;
@@ -97,7 +105,7 @@ void noinstr arm64_exit_nmi(struct pt_regs *regs)
__nmi_exit();
}
-asmlinkage void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs)
+static void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs)
{
if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs))
arm64_enter_nmi(regs);
@@ -105,7 +113,7 @@ asmlinkage void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs)
enter_from_kernel_mode(regs);
}
-asmlinkage void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs)
+static void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs)
{
if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs))
arm64_exit_nmi(regs);
@@ -113,6 +121,65 @@ asmlinkage void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs)
exit_to_kernel_mode(regs);
}
+static void __sched arm64_preempt_schedule_irq(void)
+{
+ lockdep_assert_irqs_disabled();
+
+ /*
+ * DAIF.DA are cleared at the start of IRQ/FIQ handling, and when GIC
+ * priority masking is used the GIC irqchip driver will clear DAIF.IF
+ * using gic_arch_enable_irqs() for normal IRQs. If anything is set in
+ * DAIF we must have handled an NMI, so skip preemption.
+ */
+ if (system_uses_irq_prio_masking() && read_sysreg(daif))
+ return;
+
+ /*
+ * Preempting a task from an IRQ means we leave copies of PSTATE
+ * on the stack. cpufeature's enable calls may modify PSTATE, but
+ * resuming one of these preempted tasks would undo those changes.
+ *
+ * Only allow a task to be preempted once cpufeatures have been
+ * enabled.
+ */
+ if (system_capabilities_finalized())
+ preempt_schedule_irq();
+}
+
+static void do_interrupt_handler(struct pt_regs *regs,
+ void (*handler)(struct pt_regs *))
+{
+ if (on_thread_stack())
+ call_on_irq_stack(regs, handler);
+ else
+ handler(regs);
+}
+
+extern void (*handle_arch_irq)(struct pt_regs *);
+extern void (*handle_arch_fiq)(struct pt_regs *);
+
+static void noinstr __panic_unhandled(struct pt_regs *regs, const char *vector,
+ unsigned int esr)
+{
+ arm64_enter_nmi(regs);
+
+ console_verbose();
+
+ pr_crit("Unhandled %s exception on CPU%d, ESR 0x%08x -- %s\n",
+ vector, smp_processor_id(), esr,
+ esr_get_class_string(esr));
+
+ __show_regs(regs);
+ panic("Unhandled exception");
+}
+
+#define UNHANDLED(el, regsize, vector) \
+asmlinkage void noinstr el##_##regsize##_##vector##_handler(struct pt_regs *regs) \
+{ \
+ const char *desc = #regsize "-bit " #el " " #vector; \
+ __panic_unhandled(regs, desc, read_sysreg(esr_el1)); \
+}
+
#ifdef CONFIG_ARM64_ERRATUM_1463225
static DEFINE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa);
@@ -162,6 +229,11 @@ static bool cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs)
}
#endif /* CONFIG_ARM64_ERRATUM_1463225 */
+UNHANDLED(el1t, 64, sync)
+UNHANDLED(el1t, 64, irq)
+UNHANDLED(el1t, 64, fiq)
+UNHANDLED(el1t, 64, error)
+
static void noinstr el1_abort(struct pt_regs *regs, unsigned long esr)
{
unsigned long far = read_sysreg(far_el1);
@@ -193,15 +265,6 @@ static void noinstr el1_undef(struct pt_regs *regs)
exit_to_kernel_mode(regs);
}
-static void noinstr el1_inv(struct pt_regs *regs, unsigned long esr)
-{
- enter_from_kernel_mode(regs);
- local_daif_inherit(regs);
- bad_mode(regs, 0, esr);
- local_daif_mask();
- exit_to_kernel_mode(regs);
-}
-
static void noinstr arm64_enter_el1_dbg(struct pt_regs *regs)
{
regs->lockdep_hardirqs = lockdep_hardirqs_enabled();
@@ -245,7 +308,7 @@ static void noinstr el1_fpac(struct pt_regs *regs, unsigned long esr)
exit_to_kernel_mode(regs);
}
-asmlinkage void noinstr el1_sync_handler(struct pt_regs *regs)
+asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs)
{
unsigned long esr = read_sysreg(esr_el1);
@@ -275,10 +338,50 @@ asmlinkage void noinstr el1_sync_handler(struct pt_regs *regs)
el1_fpac(regs, esr);
break;
default:
- el1_inv(regs, esr);
+ __panic_unhandled(regs, "64-bit el1h sync", esr);
}
}
+static void noinstr el1_interrupt(struct pt_regs *regs,
+ void (*handler)(struct pt_regs *))
+{
+ write_sysreg(DAIF_PROCCTX_NOIRQ, daif);
+
+ enter_el1_irq_or_nmi(regs);
+ do_interrupt_handler(regs, handler);
+
+ /*
+ * Note: thread_info::preempt_count includes both thread_info::count
+ * and thread_info::need_resched, and is not equivalent to
+ * preempt_count().
+ */
+ if (IS_ENABLED(CONFIG_PREEMPTION) &&
+ READ_ONCE(current_thread_info()->preempt_count) == 0)
+ arm64_preempt_schedule_irq();
+
+ exit_el1_irq_or_nmi(regs);
+}
+
+asmlinkage void noinstr el1h_64_irq_handler(struct pt_regs *regs)
+{
+ el1_interrupt(regs, handle_arch_irq);
+}
+
+asmlinkage void noinstr el1h_64_fiq_handler(struct pt_regs *regs)
+{
+ el1_interrupt(regs, handle_arch_fiq);
+}
+
+asmlinkage void noinstr el1h_64_error_handler(struct pt_regs *regs)
+{
+ unsigned long esr = read_sysreg(esr_el1);
+
+ local_daif_restore(DAIF_ERRCTX);
+ arm64_enter_nmi(regs);
+ do_serror(regs, esr);
+ arm64_exit_nmi(regs);
+}
+
asmlinkage void noinstr enter_from_user_mode(void)
{
lockdep_hardirqs_off(CALLER_ADDR0);
@@ -398,7 +501,7 @@ static void noinstr el0_dbg(struct pt_regs *regs, unsigned long esr)
enter_from_user_mode();
do_debug_exception(far, esr, regs);
- local_daif_restore(DAIF_PROCCTX_NOIRQ);
+ local_daif_restore(DAIF_PROCCTX);
}
static void noinstr el0_svc(struct pt_regs *regs)
@@ -415,7 +518,7 @@ static void noinstr el0_fpac(struct pt_regs *regs, unsigned long esr)
do_ptrauth_fault(regs, esr);
}
-asmlinkage void noinstr el0_sync_handler(struct pt_regs *regs)
+asmlinkage void noinstr el0t_64_sync_handler(struct pt_regs *regs)
{
unsigned long esr = read_sysreg(esr_el1);
@@ -468,6 +571,56 @@ asmlinkage void noinstr el0_sync_handler(struct pt_regs *regs)
}
}
+static void noinstr el0_interrupt(struct pt_regs *regs,
+ void (*handler)(struct pt_regs *))
+{
+ enter_from_user_mode();
+
+ write_sysreg(DAIF_PROCCTX_NOIRQ, daif);
+
+ if (regs->pc & BIT(55))
+ arm64_apply_bp_hardening();
+
+ do_interrupt_handler(regs, handler);
+}
+
+static void noinstr __el0_irq_handler_common(struct pt_regs *regs)
+{
+ el0_interrupt(regs, handle_arch_irq);
+}
+
+asmlinkage void noinstr el0t_64_irq_handler(struct pt_regs *regs)
+{
+ __el0_irq_handler_common(regs);
+}
+
+static void noinstr __el0_fiq_handler_common(struct pt_regs *regs)
+{
+ el0_interrupt(regs, handle_arch_fiq);
+}
+
+asmlinkage void noinstr el0t_64_fiq_handler(struct pt_regs *regs)
+{
+ __el0_fiq_handler_common(regs);
+}
+
+static void __el0_error_handler_common(struct pt_regs *regs)
+{
+ unsigned long esr = read_sysreg(esr_el1);
+
+ enter_from_user_mode();
+ local_daif_restore(DAIF_ERRCTX);
+ arm64_enter_nmi(regs);
+ do_serror(regs, esr);
+ arm64_exit_nmi(regs);
+ local_daif_restore(DAIF_PROCCTX);
+}
+
+asmlinkage void noinstr el0t_64_error_handler(struct pt_regs *regs)
+{
+ __el0_error_handler_common(regs);
+}
+
#ifdef CONFIG_COMPAT
static void noinstr el0_cp15(struct pt_regs *regs, unsigned long esr)
{
@@ -483,7 +636,7 @@ static void noinstr el0_svc_compat(struct pt_regs *regs)
do_el0_svc_compat(regs);
}
-asmlinkage void noinstr el0_sync_compat_handler(struct pt_regs *regs)
+asmlinkage void noinstr el0t_32_sync_handler(struct pt_regs *regs)
{
unsigned long esr = read_sysreg(esr_el1);
@@ -526,4 +679,71 @@ asmlinkage void noinstr el0_sync_compat_handler(struct pt_regs *regs)
el0_inv(regs, esr);
}
}
+
+asmlinkage void noinstr el0t_32_irq_handler(struct pt_regs *regs)
+{
+ __el0_irq_handler_common(regs);
+}
+
+asmlinkage void noinstr el0t_32_fiq_handler(struct pt_regs *regs)
+{
+ __el0_fiq_handler_common(regs);
+}
+
+asmlinkage void noinstr el0t_32_error_handler(struct pt_regs *regs)
+{
+ __el0_error_handler_common(regs);
+}
+#else /* CONFIG_COMPAT */
+UNHANDLED(el0t, 32, sync)
+UNHANDLED(el0t, 32, irq)
+UNHANDLED(el0t, 32, fiq)
+UNHANDLED(el0t, 32, error)
#endif /* CONFIG_COMPAT */
+
+#ifdef CONFIG_VMAP_STACK
+asmlinkage void noinstr handle_bad_stack(struct pt_regs *regs)
+{
+ unsigned int esr = read_sysreg(esr_el1);
+ unsigned long far = read_sysreg(far_el1);
+
+ arm64_enter_nmi(regs);
+ panic_bad_stack(regs, esr, far);
+}
+#endif /* CONFIG_VMAP_STACK */
+
+#ifdef CONFIG_ARM_SDE_INTERFACE
+asmlinkage noinstr unsigned long
+__sdei_handler(struct pt_regs *regs, struct sdei_registered_event *arg)
+{
+ unsigned long ret;
+
+ /*
+ * We didn't take an exception to get here, so the HW hasn't
+ * set/cleared bits in PSTATE that we may rely on.
+ *
+ * The original SDEI spec (ARM DEN 0054A) can be read ambiguously as to
+ * whether PSTATE bits are inherited unchanged or generated from
+ * scratch, and the TF-A implementation always clears PAN and always
+ * clears UAO. There are no other known implementations.
+ *
+ * Subsequent revisions (ARM DEN 0054B) follow the usual rules for how
+ * PSTATE is modified upon architectural exceptions, and so PAN is
+ * either inherited or set per SCTLR_ELx.SPAN, and UAO is always
+ * cleared.
+ *
+ * We must explicitly reset PAN to the expected state, including
+ * clearing it when the host isn't using it, in case a VM had it set.
+ */
+ if (system_uses_hw_pan())
+ set_pstate_pan(1);
+ else if (cpu_has_pan())
+ set_pstate_pan(0);
+
+ arm64_enter_nmi(regs);
+ ret = do_sdei_event(regs, arg);
+ arm64_exit_nmi(regs);
+
+ return ret;
+}
+#endif /* CONFIG_ARM_SDE_INTERFACE */
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 3153f1448cdb..863d44f73028 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -33,12 +33,6 @@
* Context tracking and irqflag tracing need to instrument transitions between
* user and kernel mode.
*/
- .macro user_exit_irqoff
-#if defined(CONFIG_CONTEXT_TRACKING) || defined(CONFIG_TRACE_IRQFLAGS)
- bl enter_from_user_mode
-#endif
- .endm
-
.macro user_enter_irqoff
#if defined(CONFIG_CONTEXT_TRACKING) || defined(CONFIG_TRACE_IRQFLAGS)
bl exit_to_user_mode
@@ -51,16 +45,7 @@
.endr
.endm
-/*
- * Bad Abort numbers
- *-----------------
- */
-#define BAD_SYNC 0
-#define BAD_IRQ 1
-#define BAD_FIQ 2
-#define BAD_ERROR 3
-
- .macro kernel_ventry, el, label, regsize = 64
+ .macro kernel_ventry, el:req, ht:req, regsize:req, label:req
.align 7
#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
.if \el == 0
@@ -87,7 +72,7 @@ alternative_else_nop_endif
tbnz x0, #THREAD_SHIFT, 0f
sub x0, sp, x0 // x0'' = sp' - x0' = (sp + x0) - sp = x0
sub sp, sp, x0 // sp'' = sp' - x0 = (sp + x0) - x0 = sp
- b el\()\el\()_\label
+ b el\el\ht\()_\regsize\()_\label
0:
/*
@@ -119,7 +104,7 @@ alternative_else_nop_endif
sub sp, sp, x0
mrs x0, tpidrro_el0
#endif
- b el\()\el\()_\label
+ b el\el\ht\()_\regsize\()_\label
.endm
.macro tramp_alias, dst, sym
@@ -486,63 +471,12 @@ SYM_CODE_START_LOCAL(__swpan_exit_el0)
SYM_CODE_END(__swpan_exit_el0)
#endif
- .macro irq_stack_entry
- mov x19, sp // preserve the original sp
-#ifdef CONFIG_SHADOW_CALL_STACK
- mov x24, scs_sp // preserve the original shadow stack
-#endif
-
- /*
- * Compare sp with the base of the task stack.
- * If the top ~(THREAD_SIZE - 1) bits match, we are on a task stack,
- * and should switch to the irq stack.
- */
- ldr x25, [tsk, TSK_STACK]
- eor x25, x25, x19
- and x25, x25, #~(THREAD_SIZE - 1)
- cbnz x25, 9998f
-
- ldr_this_cpu x25, irq_stack_ptr, x26
- mov x26, #IRQ_STACK_SIZE
- add x26, x25, x26
-
- /* switch to the irq stack */
- mov sp, x26
-
-#ifdef CONFIG_SHADOW_CALL_STACK
- /* also switch to the irq shadow stack */
- ldr_this_cpu scs_sp, irq_shadow_call_stack_ptr, x26
-#endif
-
-9998:
- .endm
-
- /*
- * The callee-saved regs (x19-x29) should be preserved between
- * irq_stack_entry and irq_stack_exit, but note that kernel_entry
- * uses x20-x23 to store data for later use.
- */
- .macro irq_stack_exit
- mov sp, x19
-#ifdef CONFIG_SHADOW_CALL_STACK
- mov scs_sp, x24
-#endif
- .endm
-
/* GPRs used by entry code */
tsk .req x28 // current thread_info
/*
* Interrupt handling.
*/
- .macro irq_handler, handler:req
- ldr_l x1, \handler
- mov x0, sp
- irq_stack_entry
- blr x1
- irq_stack_exit
- .endm
-
.macro gic_prio_kentry_setup, tmp:req
#ifdef CONFIG_ARM64_PSEUDO_NMI
alternative_if ARM64_HAS_IRQ_PRIO_MASKING
@@ -552,45 +486,6 @@ tsk .req x28 // current thread_info
#endif
.endm
- .macro el1_interrupt_handler, handler:req
- enable_da
-
- mov x0, sp
- bl enter_el1_irq_or_nmi
-
- irq_handler \handler
-
-#ifdef CONFIG_PREEMPTION
- ldr x24, [tsk, #TSK_TI_PREEMPT] // get preempt count
-alternative_if ARM64_HAS_IRQ_PRIO_MASKING
- /*
- * DA were cleared at start of handling, and IF are cleared by
- * the GIC irqchip driver using gic_arch_enable_irqs() for
- * normal IRQs. If anything is set, it means we come back from
- * an NMI instead of a normal IRQ, so skip preemption
- */
- mrs x0, daif
- orr x24, x24, x0
-alternative_else_nop_endif
- cbnz x24, 1f // preempt count != 0 || NMI return path
- bl arm64_preempt_schedule_irq // irq en/disable is done inside
-1:
-#endif
-
- mov x0, sp
- bl exit_el1_irq_or_nmi
- .endm
-
- .macro el0_interrupt_handler, handler:req
- user_exit_irqoff
- enable_da
-
- tbz x22, #55, 1f
- bl do_el0_irq_bp_hardening
-1:
- irq_handler \handler
- .endm
-
.text
/*
@@ -600,32 +495,25 @@ alternative_else_nop_endif
.align 11
SYM_CODE_START(vectors)
- kernel_ventry 1, sync_invalid // Synchronous EL1t
- kernel_ventry 1, irq_invalid // IRQ EL1t
- kernel_ventry 1, fiq_invalid // FIQ EL1t
- kernel_ventry 1, error_invalid // Error EL1t
-
- kernel_ventry 1, sync // Synchronous EL1h
- kernel_ventry 1, irq // IRQ EL1h
- kernel_ventry 1, fiq // FIQ EL1h
- kernel_ventry 1, error // Error EL1h
-
- kernel_ventry 0, sync // Synchronous 64-bit EL0
- kernel_ventry 0, irq // IRQ 64-bit EL0
- kernel_ventry 0, fiq // FIQ 64-bit EL0
- kernel_ventry 0, error // Error 64-bit EL0
-
-#ifdef CONFIG_COMPAT
- kernel_ventry 0, sync_compat, 32 // Synchronous 32-bit EL0
- kernel_ventry 0, irq_compat, 32 // IRQ 32-bit EL0
- kernel_ventry 0, fiq_compat, 32 // FIQ 32-bit EL0
- kernel_ventry 0, error_compat, 32 // Error 32-bit EL0
-#else
- kernel_ventry 0, sync_invalid, 32 // Synchronous 32-bit EL0
- kernel_ventry 0, irq_invalid, 32 // IRQ 32-bit EL0
- kernel_ventry 0, fiq_invalid, 32 // FIQ 32-bit EL0
- kernel_ventry 0, error_invalid, 32 // Error 32-bit EL0
-#endif
+ kernel_ventry 1, t, 64, sync // Synchronous EL1t
+ kernel_ventry 1, t, 64, irq // IRQ EL1t
+ kernel_ventry 1, t, 64, fiq // FIQ EL1h
+ kernel_ventry 1, t, 64, error // Error EL1t
+
+ kernel_ventry 1, h, 64, sync // Synchronous EL1h
+ kernel_ventry 1, h, 64, irq // IRQ EL1h
+ kernel_ventry 1, h, 64, fiq // FIQ EL1h
+ kernel_ventry 1, h, 64, error // Error EL1h
+
+ kernel_ventry 0, t, 64, sync // Synchronous 64-bit EL0
+ kernel_ventry 0, t, 64, irq // IRQ 64-bit EL0
+ kernel_ventry 0, t, 64, fiq // FIQ 64-bit EL0
+ kernel_ventry 0, t, 64, error // Error 64-bit EL0
+
+ kernel_ventry 0, t, 32, sync // Synchronous 32-bit EL0
+ kernel_ventry 0, t, 32, irq // IRQ 32-bit EL0
+ kernel_ventry 0, t, 32, fiq // FIQ 32-bit EL0
+ kernel_ventry 0, t, 32, error // Error 32-bit EL0
SYM_CODE_END(vectors)
#ifdef CONFIG_VMAP_STACK
@@ -656,147 +544,46 @@ __bad_stack:
ASM_BUG()
#endif /* CONFIG_VMAP_STACK */
-/*
- * Invalid mode handlers
- */
- .macro inv_entry, el, reason, regsize = 64
+
+ .macro entry_handler el:req, ht:req, regsize:req, label:req
+SYM_CODE_START_LOCAL(el\el\ht\()_\regsize\()_\label)
kernel_entry \el, \regsize
mov x0, sp
- mov x1, #\reason
- mrs x2, esr_el1
- bl bad_mode
- ASM_BUG()
+ bl el\el\ht\()_\regsize\()_\label\()_handler
+ .if \el == 0
+ b ret_to_user
+ .else
+ b ret_to_kernel
+ .endif
+SYM_CODE_END(el\el\ht\()_\regsize\()_\label)
.endm
-SYM_CODE_START_LOCAL(el0_sync_invalid)
- inv_entry 0, BAD_SYNC
-SYM_CODE_END(el0_sync_invalid)
-
-SYM_CODE_START_LOCAL(el0_irq_invalid)
- inv_entry 0, BAD_IRQ
-SYM_CODE_END(el0_irq_invalid)
-
-SYM_CODE_START_LOCAL(el0_fiq_invalid)
- inv_entry 0, BAD_FIQ
-SYM_CODE_END(el0_fiq_invalid)
-
-SYM_CODE_START_LOCAL(el0_error_invalid)
- inv_entry 0, BAD_ERROR
-SYM_CODE_END(el0_error_invalid)
-
-SYM_CODE_START_LOCAL(el1_sync_invalid)
- inv_entry 1, BAD_SYNC
-SYM_CODE_END(el1_sync_invalid)
-
-SYM_CODE_START_LOCAL(el1_irq_invalid)
- inv_entry 1, BAD_IRQ
-SYM_CODE_END(el1_irq_invalid)
-
-SYM_CODE_START_LOCAL(el1_fiq_invalid)
- inv_entry 1, BAD_FIQ
-SYM_CODE_END(el1_fiq_invalid)
-
-SYM_CODE_START_LOCAL(el1_error_invalid)
- inv_entry 1, BAD_ERROR
-SYM_CODE_END(el1_error_invalid)
-
/*
- * EL1 mode handlers.
+ * Early exception handlers
*/
- .align 6
-SYM_CODE_START_LOCAL_NOALIGN(el1_sync)
- kernel_entry 1
- mov x0, sp
- bl el1_sync_handler
- kernel_exit 1
-SYM_CODE_END(el1_sync)
-
- .align 6
-SYM_CODE_START_LOCAL_NOALIGN(el1_irq)
- kernel_entry 1
- el1_interrupt_handler handle_arch_irq
- kernel_exit 1
-SYM_CODE_END(el1_irq)
-
-SYM_CODE_START_LOCAL_NOALIGN(el1_fiq)
- kernel_entry 1
- el1_interrupt_handler handle_arch_fiq
- kernel_exit 1
-SYM_CODE_END(el1_fiq)
-
-/*
- * EL0 mode handlers.
- */
- .align 6
-SYM_CODE_START_LOCAL_NOALIGN(el0_sync)
- kernel_entry 0
- mov x0, sp
- bl el0_sync_handler
- b ret_to_user
-SYM_CODE_END(el0_sync)
-
-#ifdef CONFIG_COMPAT
- .align 6
-SYM_CODE_START_LOCAL_NOALIGN(el0_sync_compat)
- kernel_entry 0, 32
- mov x0, sp
- bl el0_sync_compat_handler
- b ret_to_user
-SYM_CODE_END(el0_sync_compat)
-
- .align 6
-SYM_CODE_START_LOCAL_NOALIGN(el0_irq_compat)
- kernel_entry 0, 32
- b el0_irq_naked
-SYM_CODE_END(el0_irq_compat)
-
-SYM_CODE_START_LOCAL_NOALIGN(el0_fiq_compat)
- kernel_entry 0, 32
- b el0_fiq_naked
-SYM_CODE_END(el0_fiq_compat)
-
-SYM_CODE_START_LOCAL_NOALIGN(el0_error_compat)
- kernel_entry 0, 32
- b el0_error_naked
-SYM_CODE_END(el0_error_compat)
-#endif
-
- .align 6
-SYM_CODE_START_LOCAL_NOALIGN(el0_irq)
- kernel_entry 0
-el0_irq_naked:
- el0_interrupt_handler handle_arch_irq
- b ret_to_user
-SYM_CODE_END(el0_irq)
-
-SYM_CODE_START_LOCAL_NOALIGN(el0_fiq)
- kernel_entry 0
-el0_fiq_naked:
- el0_interrupt_handler handle_arch_fiq
- b ret_to_user
-SYM_CODE_END(el0_fiq)
-
-SYM_CODE_START_LOCAL(el1_error)
- kernel_entry 1
- mrs x1, esr_el1
- enable_dbg
- mov x0, sp
- bl do_serror
+ entry_handler 1, t, 64, sync
+ entry_handler 1, t, 64, irq
+ entry_handler 1, t, 64, fiq
+ entry_handler 1, t, 64, error
+
+ entry_handler 1, h, 64, sync
+ entry_handler 1, h, 64, irq
+ entry_handler 1, h, 64, fiq
+ entry_handler 1, h, 64, error
+
+ entry_handler 0, t, 64, sync
+ entry_handler 0, t, 64, irq
+ entry_handler 0, t, 64, fiq
+ entry_handler 0, t, 64, error
+
+ entry_handler 0, t, 32, sync
+ entry_handler 0, t, 32, irq
+ entry_handler 0, t, 32, fiq
+ entry_handler 0, t, 32, error
+
+SYM_CODE_START_LOCAL(ret_to_kernel)
kernel_exit 1
-SYM_CODE_END(el1_error)
-
-SYM_CODE_START_LOCAL(el0_error)
- kernel_entry 0
-el0_error_naked:
- mrs x25, esr_el1
- user_exit_irqoff
- enable_dbg
- mov x0, sp
- mov x1, x25
- bl do_serror
- enable_da
- b ret_to_user
-SYM_CODE_END(el0_error)
+SYM_CODE_END(ret_to_kernel)
/*
* "slow" syscall return path.
@@ -998,6 +785,42 @@ SYM_CODE_START(ret_from_fork)
SYM_CODE_END(ret_from_fork)
NOKPROBE(ret_from_fork)
+/*
+ * void call_on_irq_stack(struct pt_regs *regs,
+ * void (*func)(struct pt_regs *));
+ *
+ * Calls func(regs) using this CPU's irq stack and shadow irq stack.
+ */
+SYM_FUNC_START(call_on_irq_stack)
+#ifdef CONFIG_SHADOW_CALL_STACK
+ stp scs_sp, xzr, [sp, #-16]!
+ ldr_this_cpu scs_sp, irq_shadow_call_stack_ptr, x17
+#endif
+ /* Create a frame record to save our LR and SP (implicit in FP) */
+ stp x29, x30, [sp, #-16]!
+ mov x29, sp
+
+ ldr_this_cpu x16, irq_stack_ptr, x17
+ mov x15, #IRQ_STACK_SIZE
+ add x16, x16, x15
+
+ /* Move to the new stack and call the function there */
+ mov sp, x16
+ blr x1
+
+ /*
+ * Restore the SP from the FP, and restore the FP and LR from the frame
+ * record.
+ */
+ mov sp, x29
+ ldp x29, x30, [sp], #16
+#ifdef CONFIG_SHADOW_CALL_STACK
+ ldp scs_sp, xzr, [sp], #16
+#endif
+ ret
+SYM_FUNC_END(call_on_irq_stack)
+NOKPROBE(call_on_irq_stack)
+
#ifdef CONFIG_ARM_SDE_INTERFACE
#include <asm/sdei.h>
diff --git a/arch/arm64/kernel/idle.c b/arch/arm64/kernel/idle.c
new file mode 100644
index 000000000000..a2cfbacec2bb
--- /dev/null
+++ b/arch/arm64/kernel/idle.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Low-level idle sequences
+ */
+
+#include <linux/cpu.h>
+#include <linux/irqflags.h>
+
+#include <asm/barrier.h>
+#include <asm/cpuidle.h>
+#include <asm/cpufeature.h>
+#include <asm/sysreg.h>
+
+/*
+ * cpu_do_idle()
+ *
+ * Idle the processor (wait for interrupt).
+ *
+ * If the CPU supports priority masking we must do additional work to
+ * ensure that interrupts are not masked at the PMR (because the core will
+ * not wake up if we block the wake up signal in the interrupt controller).
+ */
+void noinstr cpu_do_idle(void)
+{
+ struct arm_cpuidle_irq_context context;
+
+ arm_cpuidle_save_irq_context(&context);
+
+ dsb(sy);
+ wfi();
+
+ arm_cpuidle_restore_irq_context(&context);
+}
+
+/*
+ * This is our default idle handler.
+ */
+void noinstr arch_cpu_idle(void)
+{
+ /*
+ * This should do all the clock switching and wait for interrupt
+ * tricks
+ */
+ cpu_do_idle();
+ raw_local_irq_enable();
+}
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 3925ec3128ec..6b8b4b3e357a 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -18,7 +18,6 @@
#include <linux/sched/task.h>
#include <linux/sched/task_stack.h>
#include <linux/kernel.h>
-#include <linux/lockdep.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/nospec.h>
@@ -48,7 +47,6 @@
#include <asm/alternative.h>
#include <asm/compat.h>
#include <asm/cpufeature.h>
-#include <asm/cpuidle.h>
#include <asm/cacheflush.h>
#include <asm/exec.h>
#include <asm/fpsimd.h>
@@ -74,40 +72,6 @@ EXPORT_SYMBOL_GPL(pm_power_off);
void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
-/*
- * cpu_do_idle()
- *
- * Idle the processor (wait for interrupt).
- *
- * If the CPU supports priority masking we must do additional work to
- * ensure that interrupts are not masked at the PMR (because the core will
- * not wake up if we block the wake up signal in the interrupt controller).
- */
-void noinstr cpu_do_idle(void)
-{
- struct arm_cpuidle_irq_context context;
-
- arm_cpuidle_save_irq_context(&context);
-
- dsb(sy);
- wfi();
-
- arm_cpuidle_restore_irq_context(&context);
-}
-
-/*
- * This is our default idle handler.
- */
-void noinstr arch_cpu_idle(void)
-{
- /*
- * This should do all the clock switching and wait for interrupt
- * tricks
- */
- cpu_do_idle();
- raw_local_irq_enable();
-}
-
#ifdef CONFIG_HOTPLUG_CPU
void arch_cpu_idle_dead(void)
{
@@ -723,22 +687,6 @@ static int __init tagged_addr_init(void)
core_initcall(tagged_addr_init);
#endif /* CONFIG_ARM64_TAGGED_ADDR_ABI */
-asmlinkage void __sched arm64_preempt_schedule_irq(void)
-{
- lockdep_assert_irqs_disabled();
-
- /*
- * Preempting a task from an IRQ means we leave copies of PSTATE
- * on the stack. cpufeature's enable calls may modify PSTATE, but
- * resuming one of these preempted tasks would undo those changes.
- *
- * Only allow a task to be preempted once cpufeatures have been
- * enabled.
- */
- if (system_capabilities_finalized())
- preempt_schedule_irq();
-}
-
#ifdef CONFIG_BINFMT_ELF
int arch_elf_adjust_prot(int prot, const struct arch_elf_state *state,
bool has_interp, bool is_interp)
diff --git a/arch/arm64/kernel/sdei.c b/arch/arm64/kernel/sdei.c
index c524f96f97c4..47f77d1234cb 100644
--- a/arch/arm64/kernel/sdei.c
+++ b/arch/arm64/kernel/sdei.c
@@ -233,13 +233,13 @@ out_err:
}
/*
- * __sdei_handler() returns one of:
+ * do_sdei_event() returns one of:
* SDEI_EV_HANDLED - success, return to the interrupted context.
* SDEI_EV_FAILED - failure, return this error code to firmare.
* virtual-address - success, return to this address.
*/
-static __kprobes unsigned long _sdei_handler(struct pt_regs *regs,
- struct sdei_registered_event *arg)
+unsigned long __kprobes do_sdei_event(struct pt_regs *regs,
+ struct sdei_registered_event *arg)
{
u32 mode;
int i, err = 0;
@@ -294,45 +294,3 @@ static __kprobes unsigned long _sdei_handler(struct pt_regs *regs,
return vbar + 0x480;
}
-
-static void __kprobes notrace __sdei_pstate_entry(void)
-{
- /*
- * The original SDEI spec (ARM DEN 0054A) can be read ambiguously as to
- * whether PSTATE bits are inherited unchanged or generated from
- * scratch, and the TF-A implementation always clears PAN and always
- * clears UAO. There are no other known implementations.
- *
- * Subsequent revisions (ARM DEN 0054B) follow the usual rules for how
- * PSTATE is modified upon architectural exceptions, and so PAN is
- * either inherited or set per SCTLR_ELx.SPAN, and UAO is always
- * cleared.
- *
- * We must explicitly reset PAN to the expected state, including
- * clearing it when the host isn't using it, in case a VM had it set.
- */
- if (system_uses_hw_pan())
- set_pstate_pan(1);
- else if (cpu_has_pan())
- set_pstate_pan(0);
-}
-
-asmlinkage noinstr unsigned long
-__sdei_handler(struct pt_regs *regs, struct sdei_registered_event *arg)
-{
- unsigned long ret;
-
- /*
- * We didn't take an exception to get here, so the HW hasn't
- * set/cleared bits in PSTATE that we may rely on. Initialize PAN.
- */
- __sdei_pstate_entry();
-
- arm64_enter_nmi(regs);
-
- ret = _sdei_handler(regs, arg);
-
- arm64_exit_nmi(regs);
-
- return ret;
-}
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index a05d34f0e82a..af941996eb5f 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -45,13 +45,6 @@
#include <asm/system_misc.h>
#include <asm/sysreg.h>
-static const char *handler[] = {
- "Synchronous Abort",
- "IRQ",
- "FIQ",
- "Error"
-};
-
int show_unhandled_signals = 0;
static void dump_kernel_instr(const char *lvl, struct pt_regs *regs)
@@ -751,27 +744,8 @@ const char *esr_get_class_string(u32 esr)
}
/*
- * bad_mode handles the impossible case in the exception vector. This is always
- * fatal.
- */
-asmlinkage void notrace bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
-{
- arm64_enter_nmi(regs);
-
- console_verbose();
-
- pr_crit("Bad mode in %s handler detected on CPU%d, code 0x%08x -- %s\n",
- handler[reason], smp_processor_id(), esr,
- esr_get_class_string(esr));
-
- __show_regs(regs);
- local_daif_mask();
- panic("bad mode");
-}
-
-/*
* bad_el0_sync handles unexpected, but potentially recoverable synchronous
- * exceptions taken from EL0. Unlike bad_mode, this returns.
+ * exceptions taken from EL0.
*/
void bad_el0_sync(struct pt_regs *regs, int reason, unsigned int esr)
{
@@ -789,15 +763,11 @@ void bad_el0_sync(struct pt_regs *regs, int reason, unsigned int esr)
DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack)
__aligned(16);
-asmlinkage void noinstr handle_bad_stack(struct pt_regs *regs)
+void panic_bad_stack(struct pt_regs *regs, unsigned int esr, unsigned long far)
{
unsigned long tsk_stk = (unsigned long)current->stack;
unsigned long irq_stk = (unsigned long)this_cpu_read(irq_stack_ptr);
unsigned long ovf_stk = (unsigned long)this_cpu_ptr(overflow_stack);
- unsigned int esr = read_sysreg(esr_el1);
- unsigned long far = read_sysreg(far_el1);
-
- arm64_enter_nmi(regs);
console_verbose();
pr_emerg("Insufficient stack space to handle exception!");
@@ -870,15 +840,11 @@ bool arm64_is_fatal_ras_serror(struct pt_regs *regs, unsigned int esr)
}
}
-asmlinkage void noinstr do_serror(struct pt_regs *regs, unsigned int esr)
+void do_serror(struct pt_regs *regs, unsigned int esr)
{
- arm64_enter_nmi(regs);
-
/* non-RAS errors are not containable */
if (!arm64_is_ras_serror(esr) || arm64_is_fatal_ras_serror(regs, esr))
arm64_serror_panic(regs, esr);
-
- arm64_exit_nmi(regs);
}
/* GENERIC_BUG traps */
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 871c82ab0a30..3b4a4adfddfd 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -836,13 +836,6 @@ void do_mem_abort(unsigned long far, unsigned int esr, struct pt_regs *regs)
}
NOKPROBE_SYMBOL(do_mem_abort);
-void do_el0_irq_bp_hardening(void)
-{
- /* PC has already been checked in entry.S */
- arm64_apply_bp_hardening();
-}
-NOKPROBE_SYMBOL(do_el0_irq_bp_hardening);
-
void do_sp_pc_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs)
{
arm64_notify_die("SP/PC alignment exception", regs, SIGBUS, BUS_ADRALN,