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