sh: unwinder: Use a special bug flag for unwinder traps.
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>
diff --git a/arch/sh/include/asm/bug.h b/arch/sh/include/asm/bug.h
index b7d9822..23c5504 100644
--- a/arch/sh/include/asm/bug.h
+++ b/arch/sh/include/asm/bug.h
@@ -1,8 +1,8 @@
#ifndef __ASM_SH_BUG_H
#define __ASM_SH_BUG_H
-#define TRAPA_UNWINDER_BUG_OPCODE 0xc33b /* trapa #0x3b */
#define TRAPA_BUG_OPCODE 0xc33e /* trapa #0x3e */
+#define BUGFLAG_UNWINDER (1 << 1)
#ifdef CONFIG_GENERIC_BUG
#define HAVE_ARCH_BUG
@@ -73,15 +73,16 @@
unlikely(__ret_warn_on); \
})
-#define UNWINDER_BUG() \
+#define UNWINDER_BUG() \
do { \
__asm__ __volatile__ ( \
"1:\t.short %O0\n" \
- _EMIT_BUG_ENTRY \
+ _EMIT_BUG_ENTRY \
: \
- : "n" (TRAPA_UNWINDER_BUG_OPCODE), \
+ : "n" (TRAPA_BUG_OPCODE), \
"i" (__FILE__), \
- "i" (__LINE__), "i" (0), \
+ "i" (__LINE__), \
+ "i" (BUGFLAG_UNWINDER), \
"i" (sizeof(struct bug_entry))); \
} while (0)
diff --git a/arch/sh/kernel/debugtraps.S b/arch/sh/kernel/debugtraps.S
index cb00e4a..5917413 100644
--- a/arch/sh/kernel/debugtraps.S
+++ b/arch/sh/kernel/debugtraps.S
@@ -21,10 +21,6 @@
#define sh_bios_handler debug_trap_handler
#endif
-#if !defined(CONFIG_DWARF_UNWINDER)
-#define unwinder_trap_handler debug_trap_handler
-#endif
-
.data
ENTRY(debug_trap_table)
@@ -39,7 +35,7 @@
.long debug_trap_handler /* 0x38 */
.long debug_trap_handler /* 0x39 */
.long debug_trap_handler /* 0x3a */
- .long unwinder_trap_handler /* 0x3b */
+ .long debug_trap_handler /* 0x3b */
.long breakpoint_trap_handler /* 0x3c */
.long singlestep_trap_handler /* 0x3d */
.long bug_trap_handler /* 0x3e */
diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c
index 881b9a3..f69bd96 100644
--- a/arch/sh/kernel/traps.c
+++ b/arch/sh/kernel/traps.c
@@ -5,18 +5,32 @@
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
+#include <asm/unwinder.h>
#include <asm/system.h>
#ifdef CONFIG_BUG
void handle_BUG(struct pt_regs *regs)
{
+ const struct bug_entry *bug;
+ unsigned long bugaddr = regs->pc;
enum bug_trap_type tt;
- tt = report_bug(regs->pc, regs);
+
+ if (!is_valid_bugaddr(bugaddr))
+ goto invalid;
+
+ bug = find_bug(bugaddr);
+
+ /* Switch unwinders when unwind_stack() is called */
+ if (bug->flags & BUGFLAG_UNWINDER)
+ unwinder_faulted = 1;
+
+ tt = report_bug(bugaddr, regs);
if (tt == BUG_TRAP_TYPE_WARN) {
- regs->pc += instruction_size(regs->pc);
+ regs->pc += instruction_size(bugaddr);
return;
}
+invalid:
die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
}
@@ -28,8 +42,7 @@
return 0;
if (probe_kernel_address((insn_size_t *)addr, opcode))
return 0;
-
- if (opcode == TRAPA_BUG_OPCODE || opcode == TRAPA_UNWINDER_BUG_OPCODE)
+ if (opcode == TRAPA_BUG_OPCODE)
return 1;
return 0;
diff --git a/arch/sh/kernel/unwinder.c b/arch/sh/kernel/unwinder.c
index e83861d..468889d 100644
--- a/arch/sh/kernel/unwinder.c
+++ b/arch/sh/kernel/unwinder.c
@@ -161,25 +161,4 @@
curr_unwinder->dump(task, regs, sp, ops, data);
}
-
-/*
- * Trap handler for UWINDER_BUG() statements. We must switch to the
- * unwinder with the next highest rating.
- */
-BUILD_TRAP_HANDLER(unwinder)
-{
- insn_size_t insn;
- TRAP_HANDLER_DECL;
-
- /* Rewind */
- regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
- insn = *(insn_size_t *)instruction_pointer(regs);
-
- /* Switch unwinders when unwind_stack() is called */
- unwinder_faulted = 1;
-
-#ifdef CONFIG_BUG
- handle_BUG(regs);
-#endif
-}
EXPORT_SYMBOL_GPL(unwind_stack);