summaryrefslogtreecommitdiff
path: root/arch/arc/kernel/traps.c
diff options
context:
space:
mode:
authorVineet Gupta <vgupta@synopsys.com>2013-01-18 15:12:18 +0530
committerVineet Gupta <vgupta@synopsys.com>2013-02-11 20:00:37 +0530
commit054419ed8405da7aa93f88f698d696980efd3e37 (patch)
tree16b0376000cd0383eb8c5c064984c5c414042551 /arch/arc/kernel/traps.c
parentbacdf4809afade180a8f2171adb4cf7ec715d139 (diff)
ARC: Non-MMU Exception Handling
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/kernel/traps.c')
-rw-r--r--arch/arc/kernel/traps.c125
1 files changed, 125 insertions, 0 deletions
diff --git a/arch/arc/kernel/traps.c b/arch/arc/kernel/traps.c
new file mode 100644
index 000000000000..fd2457cec226
--- /dev/null
+++ b/arch/arc/kernel/traps.c
@@ -0,0 +1,125 @@
+/*
+ * Traps/Non-MMU Exception handling for ARC
+ *
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Rahul Trivedi: Codito Technologies 2004
+ */
+
+#include <linux/sched.h>
+#include <linux/kdebug.h>
+#include <linux/uaccess.h>
+#include <asm/ptrace.h>
+#include <asm/setup.h>
+
+void __init trap_init(void)
+{
+ return;
+}
+
+void die(const char *str, struct pt_regs *regs, unsigned long address,
+ unsigned long cause_reg)
+{
+ show_kernel_fault_diag(str, regs, address, cause_reg);
+
+ /* DEAD END */
+ __asm__("flag 1");
+}
+
+/*
+ * Helper called for bulk of exceptions NOT needing specific handling
+ * -for user faults enqueues requested signal
+ * -for kernel, chk if due to copy_(to|from)_user, otherwise die()
+ */
+static noinline int handle_exception(unsigned long cause, char *str,
+ struct pt_regs *regs, siginfo_t *info)
+{
+ if (user_mode(regs)) {
+ struct task_struct *tsk = current;
+
+ tsk->thread.fault_address = (__force unsigned int)info->si_addr;
+ tsk->thread.cause_code = cause;
+
+ force_sig_info(info->si_signo, info, tsk);
+
+ } else {
+ /* If not due to copy_(to|from)_user, we are doomed */
+ if (fixup_exception(regs))
+ return 0;
+
+ die(str, regs, (unsigned long)info->si_addr, cause);
+ }
+
+ return 1;
+}
+
+#define DO_ERROR_INFO(signr, str, name, sicode) \
+int name(unsigned long cause, unsigned long address, struct pt_regs *regs) \
+{ \
+ siginfo_t info = { \
+ .si_signo = signr, \
+ .si_errno = 0, \
+ .si_code = sicode, \
+ .si_addr = (void __user *)address, \
+ }; \
+ return handle_exception(cause, str, regs, &info);\
+}
+
+/*
+ * Entry points for exceptions NOT needing specific handling
+ */
+DO_ERROR_INFO(SIGILL, "Priv Op/Disabled Extn", do_privilege_fault, ILL_PRVOPC)
+DO_ERROR_INFO(SIGILL, "Invalid Extn Insn", do_extension_fault, ILL_ILLOPC)
+DO_ERROR_INFO(SIGILL, "Illegal Insn (or Seq)", insterror_is_error, ILL_ILLOPC)
+DO_ERROR_INFO(SIGBUS, "Invalid Mem Access", do_memory_error, BUS_ADRERR)
+DO_ERROR_INFO(SIGTRAP, "Breakpoint Set", trap_is_brkpt, TRAP_BRKPT)
+
+DO_ERROR_INFO(SIGSEGV, "Misaligned Access", do_misaligned_access, SEGV_ACCERR)
+
+/*
+ * Entry point for miscll errors such as Nested Exceptions
+ * -Duplicate TLB entry is handled seperately though
+ */
+void do_machine_check_fault(unsigned long cause, unsigned long address,
+ struct pt_regs *regs)
+{
+ die("Machine Check Exception", regs, address, cause);
+}
+
+/*
+ * Entry point for traps induced by ARCompact TRAP_S <n> insn
+ * This is same family as TRAP0/SWI insn (use the same vector).
+ * The only difference being SWI insn take no operand, while TRAP_S does
+ * which reflects in ECR Reg as 8 bit param.
+ * Thus TRAP_S <n> can be used for specific purpose
+ * -1 used for software breakpointing (gdb)
+ * -2 used by kprobes
+ */
+void do_non_swi_trap(unsigned long cause, unsigned long address,
+ struct pt_regs *regs)
+{
+ unsigned int param = cause & 0xff;
+
+ switch (param) {
+ case 1:
+ trap_is_brkpt(cause, address, regs);
+ break;
+
+ default:
+ break;
+ }
+}
+
+/*
+ * Entry point for Instruction Error Exception
+ */
+void do_insterror_or_kprobe(unsigned long cause,
+ unsigned long address,
+ struct pt_regs *regs)
+{
+ insterror_is_error(cause, address, regs);
+}