forked from Minki/linux
e115f2c17c
This simplifies the unwinder trap handling, dropping the use of the special trapa vector and simply piggybacking on top of the BUG support. A new BUGFLAG_UNWINDER is added for flagging the unwinder fault, before continuing on with regular BUG dispatch. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
94 lines
1.8 KiB
C
94 lines
1.8 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 <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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