1e1030dccb
This implements support for NMI debugging that was shamelessly copied from the avr32 port. A bit of special magic is needed in the interrupt exception path given that the NMI exception handler is stubbed in to the regular exception handling table despite being reported in INTEVT. So we mangle the lookup and kick off an EXPEVT-style exception dispatch from the INTEVT path for exceptions that do_IRQ() has no chance of handling. As a result, we also drop the evt2irq() conversion from the do_IRQ() path and just do it in assembly. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
114 lines
2.1 KiB
C
114 lines
2.1 KiB
C
#include <linux/bug.h>
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#include <linux/io.h>
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#include <linux/types.h>
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#include <linux/kdebug.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/uaccess.h>
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#include <linux/hardirq.h>
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#include <asm/unwinder.h>
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#include <asm/system.h>
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#ifdef CONFIG_BUG
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void handle_BUG(struct pt_regs *regs)
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{
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const struct bug_entry *bug;
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unsigned long bugaddr = regs->pc;
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enum bug_trap_type tt;
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if (!is_valid_bugaddr(bugaddr))
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goto invalid;
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bug = find_bug(bugaddr);
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/* Switch unwinders when unwind_stack() is called */
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if (bug->flags & BUGFLAG_UNWINDER)
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unwinder_faulted = 1;
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tt = report_bug(bugaddr, regs);
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if (tt == BUG_TRAP_TYPE_WARN) {
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regs->pc += instruction_size(bugaddr);
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return;
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}
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invalid:
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die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
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}
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int is_valid_bugaddr(unsigned long addr)
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{
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insn_size_t opcode;
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if (addr < PAGE_OFFSET)
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return 0;
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if (probe_kernel_address((insn_size_t *)addr, opcode))
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return 0;
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if (opcode == TRAPA_BUG_OPCODE)
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return 1;
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return 0;
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}
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#endif
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/*
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* Generic trap handler.
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*/
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BUILD_TRAP_HANDLER(debug)
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{
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TRAP_HANDLER_DECL;
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/* Rewind */
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regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
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if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff,
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SIGTRAP) == NOTIFY_STOP)
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return;
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force_sig(SIGTRAP, current);
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}
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/*
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* Special handler for BUG() traps.
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*/
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BUILD_TRAP_HANDLER(bug)
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{
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TRAP_HANDLER_DECL;
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/* Rewind */
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regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
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if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
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SIGTRAP) == NOTIFY_STOP)
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return;
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#ifdef CONFIG_BUG
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if (__kernel_text_address(instruction_pointer(regs))) {
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insn_size_t insn = *(insn_size_t *)instruction_pointer(regs);
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if (insn == TRAPA_BUG_OPCODE)
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handle_BUG(regs);
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return;
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}
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#endif
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force_sig(SIGTRAP, current);
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}
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BUILD_TRAP_HANDLER(nmi)
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{
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TRAP_HANDLER_DECL;
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nmi_enter();
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switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) {
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case NOTIFY_OK:
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case NOTIFY_STOP:
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break;
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case NOTIFY_BAD:
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die("Fatal Non-Maskable Interrupt", regs, SIGINT);
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default:
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printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n");
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break;
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}
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nmi_exit();
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}
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