Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) // Copyright (C) 2017 Arm Ltd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3) #define pr_fmt(fmt) "sdei: " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) #include <linux/arm-smccc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #include <linux/arm_sdei.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) #include <linux/hardirq.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/irqflags.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/sched/task_stack.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/scs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <asm/alternative.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <asm/exception.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <asm/kprobes.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <asm/mmu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <asm/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <asm/sections.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <asm/stacktrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <asm/sysreg.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <asm/vmap_stack.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) unsigned long sdei_exit_mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26)  * VMAP'd stacks checking for stack overflow on exception using sp as a scratch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27)  * register, meaning SDEI has to switch to its own stack. We need two stacks as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28)  * a critical event may interrupt a normal event that has just taken a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29)  * synchronous exception, and is using sp as scratch register. For a critical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30)  * event interrupting a normal event, we can't reliably tell if we were on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31)  * sdei stack.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32)  * For now, we allocate stacks when the driver is probed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) DECLARE_PER_CPU(unsigned long *, sdei_stack_normal_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) DECLARE_PER_CPU(unsigned long *, sdei_stack_critical_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) #ifdef CONFIG_VMAP_STACK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) DEFINE_PER_CPU(unsigned long *, sdei_stack_normal_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) DEFINE_PER_CPU(unsigned long *, sdei_stack_critical_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) DECLARE_PER_CPU(unsigned long *, sdei_shadow_call_stack_normal_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) DECLARE_PER_CPU(unsigned long *, sdei_shadow_call_stack_critical_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) #ifdef CONFIG_SHADOW_CALL_STACK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) DEFINE_PER_CPU(unsigned long *, sdei_shadow_call_stack_normal_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) DEFINE_PER_CPU(unsigned long *, sdei_shadow_call_stack_critical_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) static void _free_sdei_stack(unsigned long * __percpu *ptr, int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	unsigned long *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	p = per_cpu(*ptr, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	if (p) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 		per_cpu(*ptr, cpu) = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 		vfree(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) static void free_sdei_stacks(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	if (!IS_ENABLED(CONFIG_VMAP_STACK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	for_each_possible_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 		_free_sdei_stack(&sdei_stack_normal_ptr, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 		_free_sdei_stack(&sdei_stack_critical_ptr, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) static int _init_sdei_stack(unsigned long * __percpu *ptr, int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	unsigned long *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	p = arch_alloc_vmap_stack(SDEI_STACK_SIZE, cpu_to_node(cpu));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	if (!p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	per_cpu(*ptr, cpu) = p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) static int init_sdei_stacks(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	if (!IS_ENABLED(CONFIG_VMAP_STACK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	for_each_possible_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 		err = _init_sdei_stack(&sdei_stack_normal_ptr, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 		err = _init_sdei_stack(&sdei_stack_critical_ptr, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 		free_sdei_stacks();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) static void _free_sdei_scs(unsigned long * __percpu *ptr, int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	void *s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	s = per_cpu(*ptr, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	if (s) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 		per_cpu(*ptr, cpu) = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 		scs_free(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) static void free_sdei_scs(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	for_each_possible_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 		_free_sdei_scs(&sdei_shadow_call_stack_normal_ptr, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 		_free_sdei_scs(&sdei_shadow_call_stack_critical_ptr, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) static int _init_sdei_scs(unsigned long * __percpu *ptr, int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	void *s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	s = scs_alloc(cpu_to_node(cpu));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	if (!s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	per_cpu(*ptr, cpu) = s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) static int init_sdei_scs(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	if (!IS_ENABLED(CONFIG_SHADOW_CALL_STACK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	for_each_possible_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 		err = _init_sdei_scs(&sdei_shadow_call_stack_normal_ptr, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 		if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 		err = _init_sdei_scs(&sdei_shadow_call_stack_critical_ptr, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 		if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		free_sdei_scs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) static bool on_sdei_normal_stack(unsigned long sp, struct stack_info *info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_normal_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	unsigned long high = low + SDEI_STACK_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	return on_stack(sp, low, high, STACK_TYPE_SDEI_NORMAL, info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) static bool on_sdei_critical_stack(unsigned long sp, struct stack_info *info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_critical_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	unsigned long high = low + SDEI_STACK_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	return on_stack(sp, low, high, STACK_TYPE_SDEI_CRITICAL, info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) bool _on_sdei_stack(unsigned long sp, struct stack_info *info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	if (!IS_ENABLED(CONFIG_VMAP_STACK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	if (on_sdei_critical_stack(sp, info))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	if (on_sdei_normal_stack(sp, info))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) unsigned long sdei_arch_get_entry_point(int conduit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	 * SDEI works between adjacent exception levels. If we booted at EL1 we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	 * assume a hypervisor is marshalling events. If we booted at EL2 and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	 * dropped to EL1 because we don't support VHE, then we can't support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	 * SDEI.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	if (is_hyp_mode_available() && !is_kernel_in_hyp_mode()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 		pr_err("Not supported on this hardware/boot configuration\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 		goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	if (init_sdei_stacks())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 		goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	if (init_sdei_scs())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 		goto out_err_free_stacks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	sdei_exit_mode = (conduit == SMCCC_CONDUIT_HVC) ? SDEI_EXIT_HVC : SDEI_EXIT_SMC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	if (arm64_kernel_unmapped_at_el0()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 		unsigned long offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		offset = (unsigned long)__sdei_asm_entry_trampoline -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 			 (unsigned long)__entry_tramp_text_start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 		return TRAMP_VALIAS + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	} else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 		return (unsigned long)__sdei_asm_handler;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) out_err_free_stacks:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	free_sdei_stacks();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) out_err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234)  * __sdei_handler() returns one of:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)  *  SDEI_EV_HANDLED -  success, return to the interrupted context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236)  *  SDEI_EV_FAILED  -  failure, return this error code to firmare.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)  *  virtual-address -  success, return to this address.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) static __kprobes unsigned long _sdei_handler(struct pt_regs *regs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 					     struct sdei_registered_event *arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	u32 mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	int i, err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	int clobbered_registers = 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	u64 elr = read_sysreg(elr_el1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 	u32 kernel_mode = read_sysreg(CurrentEL) | 1;	/* +SPSel */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	unsigned long vbar = read_sysreg(vbar_el1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	if (arm64_kernel_unmapped_at_el0())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 		clobbered_registers++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	/* Retrieve the missing registers values */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	for (i = 0; i < clobbered_registers; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 		/* from within the handler, this call always succeeds */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 		sdei_api_event_context(i, &regs->regs[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 	 * We didn't take an exception to get here, set PAN. UAO will be cleared
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 	 * by sdei_event_handler()s force_uaccess_begin() call.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 	__uaccess_enable_hw_pan();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	err = sdei_event_handler(regs, arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 		return SDEI_EV_FAILED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	if (elr != read_sysreg(elr_el1)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 		 * We took a synchronous exception from the SDEI handler.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 		 * This could deadlock, and if you interrupt KVM it will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 		 * hyp-panic instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 		pr_warn("unsafe: exception during handler\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 	mode = regs->pstate & (PSR_MODE32_BIT | PSR_MODE_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 	 * If we interrupted the kernel with interrupts masked, we always go
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	 * back to wherever we came from.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 	if (mode == kernel_mode && !interrupts_enabled(regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 		return SDEI_EV_HANDLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 	 * Otherwise, we pretend this was an IRQ. This lets user space tasks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 	 * receive signals before we return to them, and KVM to invoke it's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 	 * world switch to do the same.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 	 * See DDI0487B.a Table D1-7 'Vector offsets from vector table base
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 	 * address'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 	if (mode == kernel_mode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 		return vbar + 0x280;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	else if (mode & PSR_MODE32_BIT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 		return vbar + 0x680;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 	return vbar + 0x480;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) asmlinkage noinstr unsigned long
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) __sdei_handler(struct pt_regs *regs, struct sdei_registered_event *arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 	unsigned long ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 	arm64_enter_nmi(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 	ret = _sdei_handler(regs, arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 	arm64_exit_nmi(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) }