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// SPDX-License-Identifier: GPL-2.0
/*
* PA-RISC KGDB support
*
* Copyright (c) 2019 Sven Schnelle <svens@stackframe.org>
* Copyright (c) 2022 Helge Deller <deller@gmx.de>
*
*/
#include <linux/kgdb.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/notifier.h>
#include <linux/kdebug.h>
#include <linux/uaccess.h>
#include <asm/ptrace.h>
#include <asm/traps.h>
#include <asm/processor.h>
#include <asm/patch.h>
#include <asm/cacheflush.h>
const struct kgdb_arch arch_kgdb_ops = {
.gdb_bpt_instr = { 0x03, 0xff, 0xa0, 0x1f }
};
static int __kgdb_notify(struct die_args *args, unsigned long cmd)
{
struct pt_regs *regs = args->regs;
if (kgdb_handle_exception(1, args->signr, cmd, regs))
return NOTIFY_DONE;
return NOTIFY_STOP;
}
static int kgdb_notify(struct notifier_block *self,
unsigned long cmd, void *ptr)
{
unsigned long flags;
int ret;
local_irq_save(flags);
ret = __kgdb_notify(ptr, cmd);
local_irq_restore(flags);
return ret;
}
static struct notifier_block kgdb_notifier = {
.notifier_call = kgdb_notify,
.priority = -INT_MAX,
};
int kgdb_arch_init(void)
{
return register_die_notifier(&kgdb_notifier);
}
void kgdb_arch_exit(void)
{
unregister_die_notifier(&kgdb_notifier);
}
void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
struct parisc_gdb_regs *gr = (struct parisc_gdb_regs *)gdb_regs;
memset(gr, 0, sizeof(struct parisc_gdb_regs));
memcpy(gr->gpr, regs->gr, sizeof(gr->gpr));
memcpy(gr->fr, regs->fr, sizeof(gr->fr));
gr->sr0 = regs->sr[0];
gr->sr1 = regs->sr[1];
gr->sr2 = regs->sr[2];
gr->sr3 = regs->sr[3];
gr->sr4 = regs->sr[4];
gr->sr5 = regs->sr[5];
gr->sr6 = regs->sr[6];
gr->sr7 = regs->sr[7];
gr->sar = regs->sar;
gr->iir = regs->iir;
gr->isr = regs->isr;
gr->ior = regs->ior;
gr->ipsw = regs->ipsw;
gr->cr27 = regs->cr27;
gr->iaoq_f = regs->iaoq[0];
gr->iasq_f = regs->iasq[0];
gr->iaoq_b = regs->iaoq[1];
gr->iasq_b = regs->iasq[1];
}
void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
struct parisc_gdb_regs *gr = (struct parisc_gdb_regs *)gdb_regs;
memcpy(regs->gr, gr->gpr, sizeof(regs->gr));
memcpy(regs->fr, gr->fr, sizeof(regs->fr));
regs->sr[0] = gr->sr0;
regs->sr[1] = gr->sr1;
regs->sr[2] = gr->sr2;
regs->sr[3] = gr->sr3;
regs->sr[4] = gr->sr4;
regs->sr[5] = gr->sr5;
regs->sr[6] = gr->sr6;
regs->sr[7] = gr->sr7;
regs->sar = gr->sar;
regs->iir = gr->iir;
regs->isr = gr->isr;
regs->ior = gr->ior;
regs->ipsw = gr->ipsw;
regs->cr27 = gr->cr27;
regs->iaoq[0] = gr->iaoq_f;
regs->iasq[0] = gr->iasq_f;
regs->iaoq[1] = gr->iaoq_b;
regs->iasq[1] = gr->iasq_b;
}
void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs,
struct task_struct *task)
{
struct pt_regs *regs = task_pt_regs(task);
unsigned long gr30, iaoq;
gr30 = regs->gr[30];
iaoq = regs->iaoq[0];
regs->gr[30] = regs->ksp;
regs->iaoq[0] = regs->kpc;
pt_regs_to_gdb_regs(gdb_regs, regs);
regs->gr[30] = gr30;
regs->iaoq[0] = iaoq;
}
static void step_instruction_queue(struct pt_regs *regs)
{
regs->iaoq[0] = regs->iaoq[1];
regs->iaoq[1] += 4;
}
void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
{
regs->iaoq[0] = ip;
regs->iaoq[1] = ip + 4;
}
int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
{
int ret = copy_from_kernel_nofault(bpt->saved_instr,
(char *)bpt->bpt_addr, BREAK_INSTR_SIZE);
if (ret)
return ret;
__patch_text((void *)bpt->bpt_addr,
*(unsigned int *)&arch_kgdb_ops.gdb_bpt_instr);
return ret;
}
int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
{
__patch_text((void *)bpt->bpt_addr, *(unsigned int *)&bpt->saved_instr);
return 0;
}
int kgdb_arch_handle_exception(int trap, int signo,
int err_code, char *inbuf, char *outbuf,
struct pt_regs *regs)
{
unsigned long addr;
char *p = inbuf + 1;
switch (inbuf[0]) {
case 'D':
case 'c':
case 'k':
kgdb_contthread = NULL;
kgdb_single_step = 0;
if (kgdb_hex2long(&p, &addr))
kgdb_arch_set_pc(regs, addr);
else if (trap == 9 && regs->iir ==
PARISC_KGDB_COMPILED_BREAK_INSN)
step_instruction_queue(regs);
return 0;
case 's':
kgdb_single_step = 1;
if (kgdb_hex2long(&p, &addr)) {
kgdb_arch_set_pc(regs, addr);
} else if (trap == 9 && regs->iir ==
PARISC_KGDB_COMPILED_BREAK_INSN) {
step_instruction_queue(regs);
mtctl(-1, 0);
} else {
mtctl(0, 0);
}
regs->gr[0] |= PSW_R;
return 0;
}
return -1;
}