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) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * arch/sh/kernel/hw_breakpoint.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Unified kernel/user-space hardware breakpoint facility for the on-chip UBC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * Copyright (C) 2009 - 2010  Paul Mundt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/perf_event.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/sched/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/hw_breakpoint.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/percpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/kallsyms.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/notifier.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/kprobes.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/kdebug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <linux/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <linux/clk.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <asm/hw_breakpoint.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <asm/mmu_context.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <asm/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) #include <asm/traps.h>
^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)  * Stores the breakpoints currently in use on each breakpoint address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27)  * register for each cpus
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) static DEFINE_PER_CPU(struct perf_event *, bp_per_reg[HBP_NUM]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32)  * A dummy placeholder for early accesses until the CPUs get a chance to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33)  * register their UBCs later in the boot process.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) static struct sh_ubc ubc_dummy = { .num_events = 0 };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) static struct sh_ubc *sh_ubc __read_mostly = &ubc_dummy;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40)  * Install a perf counter breakpoint.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42)  * We seek a free UBC channel and use it for this breakpoint.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44)  * Atomic: we hold the counter->ctx->lock and we only handle variables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45)  * and registers local to this cpu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) int arch_install_hw_breakpoint(struct perf_event *bp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	struct arch_hw_breakpoint *info = counter_arch_bp(bp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	for (i = 0; i < sh_ubc->num_events; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 		struct perf_event **slot = this_cpu_ptr(&bp_per_reg[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 		if (!*slot) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 			*slot = bp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 			break;
^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) 	if (WARN_ONCE(i == sh_ubc->num_events, "Can't find any breakpoint slot"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 		return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	clk_enable(sh_ubc->clk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	sh_ubc->enable(info, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71)  * Uninstall the breakpoint contained in the given counter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73)  * First we search the debug address register it uses and then we disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74)  * it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76)  * Atomic: we hold the counter->ctx->lock and we only handle variables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77)  * and registers local to this cpu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) void arch_uninstall_hw_breakpoint(struct perf_event *bp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	struct arch_hw_breakpoint *info = counter_arch_bp(bp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	for (i = 0; i < sh_ubc->num_events; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 		struct perf_event **slot = this_cpu_ptr(&bp_per_reg[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 		if (*slot == bp) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 			*slot = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	if (WARN_ONCE(i == sh_ubc->num_events, "Can't find any breakpoint slot"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	sh_ubc->disable(info, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	clk_disable(sh_ubc->clk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) static int get_hbp_len(u16 hbp_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	unsigned int len_in_bytes = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	switch (hbp_len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	case SH_BREAKPOINT_LEN_1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		len_in_bytes = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	case SH_BREAKPOINT_LEN_2:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		len_in_bytes = 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	case SH_BREAKPOINT_LEN_4:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 		len_in_bytes = 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	case SH_BREAKPOINT_LEN_8:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 		len_in_bytes = 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	return len_in_bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)  * Check for virtual address in kernel space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	unsigned int len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	unsigned long va;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	va = hw->address;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	len = get_hbp_len(hw->len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) int arch_bp_generic_fields(int sh_len, int sh_type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 			   int *gen_len, int *gen_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	/* Len */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	switch (sh_len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	case SH_BREAKPOINT_LEN_1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 		*gen_len = HW_BREAKPOINT_LEN_1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	case SH_BREAKPOINT_LEN_2:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		*gen_len = HW_BREAKPOINT_LEN_2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	case SH_BREAKPOINT_LEN_4:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		*gen_len = HW_BREAKPOINT_LEN_4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	case SH_BREAKPOINT_LEN_8:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 		*gen_len = HW_BREAKPOINT_LEN_8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	/* Type */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	switch (sh_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	case SH_BREAKPOINT_READ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		*gen_type = HW_BREAKPOINT_R;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	case SH_BREAKPOINT_WRITE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 		*gen_type = HW_BREAKPOINT_W;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	case SH_BREAKPOINT_RW:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 		*gen_type = HW_BREAKPOINT_W | HW_BREAKPOINT_R;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) static int arch_build_bp_info(struct perf_event *bp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 			      const struct perf_event_attr *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 			      struct arch_hw_breakpoint *hw)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	hw->address = attr->bp_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	/* Len */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	switch (attr->bp_len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	case HW_BREAKPOINT_LEN_1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		hw->len = SH_BREAKPOINT_LEN_1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	case HW_BREAKPOINT_LEN_2:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 		hw->len = SH_BREAKPOINT_LEN_2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	case HW_BREAKPOINT_LEN_4:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 		hw->len = SH_BREAKPOINT_LEN_4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	case HW_BREAKPOINT_LEN_8:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		hw->len = SH_BREAKPOINT_LEN_8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 		return -EINVAL;
^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) 	/* Type */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	switch (attr->bp_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	case HW_BREAKPOINT_R:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 		hw->type = SH_BREAKPOINT_READ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	case HW_BREAKPOINT_W:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 		hw->type = SH_BREAKPOINT_WRITE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	case HW_BREAKPOINT_W | HW_BREAKPOINT_R:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 		hw->type = SH_BREAKPOINT_RW;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)  * Validate the arch-specific HW Breakpoint register settings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) int hw_breakpoint_arch_parse(struct perf_event *bp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 			     const struct perf_event_attr *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 			     struct arch_hw_breakpoint *hw)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	unsigned int align;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	ret = arch_build_bp_info(bp, attr, hw);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	switch (hw->len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 	case SH_BREAKPOINT_LEN_1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 		align = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	case SH_BREAKPOINT_LEN_2:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 		align = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	case SH_BREAKPOINT_LEN_4:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 		align = 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	case SH_BREAKPOINT_LEN_8:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 		align = 7;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 	 * Check that the low-order bits of the address are appropriate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	 * for the alignment implied by len.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	if (hw->address & align)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 	return 0;
^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) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)  * Release the user breakpoints used by ptrace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	struct thread_struct *t = &tsk->thread;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 	for (i = 0; i < sh_ubc->num_events; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 		unregister_hw_breakpoint(t->ptrace_bps[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 		t->ptrace_bps[i] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) static int __kprobes hw_breakpoint_handler(struct die_args *args)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 	int cpu, i, rc = NOTIFY_STOP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	struct perf_event *bp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 	unsigned int cmf, resume_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) 	 * Do an early return if none of the channels triggered.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	cmf = sh_ubc->triggered_mask();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 	if (unlikely(!cmf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 		return NOTIFY_DONE;
^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) 	 * By default, resume all of the active channels.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 	resume_mask = sh_ubc->active_mask();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 	 * Disable breakpoints during exception handling.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 	sh_ubc->disable_all();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	cpu = get_cpu();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 	for (i = 0; i < sh_ubc->num_events; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 		unsigned long event_mask = (1 << i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 		if (likely(!(cmf & event_mask)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 		 * The counter may be concurrently released but that can only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 		 * occur from a call_rcu() path. We can then safely fetch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 		 * the breakpoint, use its callback, touch its counter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 		 * while we are in an rcu_read_lock() path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 		rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 		bp = per_cpu(bp_per_reg[i], cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 		if (bp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 			rc = NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 		 * Reset the condition match flag to denote completion of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 		 * exception handling.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 		sh_ubc->clear_triggered_mask(event_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 		 * bp can be NULL due to concurrent perf counter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 		 * removing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 		if (!bp) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 			rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 		 * Don't restore the channel if the breakpoint is from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 		 * ptrace, as it always operates in one-shot mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 		if (bp->overflow_handler == ptrace_triggered)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 			resume_mask &= ~(1 << i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 		perf_bp_event(bp, args->regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 		/* Deliver the signal to userspace */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 		if (!arch_check_bp_in_kernelspace(&bp->hw.info)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 			force_sig_fault(SIGTRAP, TRAP_HWBKPT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 					(void __user *)NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 		rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 	if (cmf == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 		rc = NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 	sh_ubc->enable_all(resume_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 	put_cpu();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 	return rc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) BUILD_TRAP_HANDLER(breakpoint)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) 	unsigned long ex = lookup_exception_vector();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) 	TRAP_HANDLER_DECL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 	notify_die(DIE_BREAKPOINT, "breakpoint", regs, 0, ex, SIGTRAP);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367)  * Handle debug exception notifications.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) int __kprobes hw_breakpoint_exceptions_notify(struct notifier_block *unused,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) 				    unsigned long val, void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) 	struct die_args *args = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) 	if (val != DIE_BREAKPOINT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) 		return NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) 	 * If the breakpoint hasn't been triggered by the UBC, it's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) 	 * probably from a debugger, so don't do anything more here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) 	 * This also permits the UBC interface clock to remain off for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) 	 * non-UBC breakpoints, as we don't need to check the triggered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) 	 * or active channel masks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) 	if (args->trapnr != sh_ubc->trap_nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) 		return NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) 	return hw_breakpoint_handler(data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) void hw_breakpoint_pmu_read(struct perf_event *bp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) 	/* TODO */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) int register_sh_ubc(struct sh_ubc *ubc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) 	/* Bail if it's already assigned */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) 	if (sh_ubc != &ubc_dummy)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) 		return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) 	sh_ubc = ubc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) 	pr_info("HW Breakpoints: %s UBC support registered\n", ubc->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) 	WARN_ON(ubc->num_events > HBP_NUM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) }