Commit e115f2c1 authored by Paul Mundt's avatar Paul Mundt

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: default avatarPaul Mundt <lethal@linux-sh.org>
parent c153a58e
#ifndef __ASM_SH_BUG_H #ifndef __ASM_SH_BUG_H
#define __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 TRAPA_BUG_OPCODE 0xc33e /* trapa #0x3e */
#define BUGFLAG_UNWINDER (1 << 1)
#ifdef CONFIG_GENERIC_BUG #ifdef CONFIG_GENERIC_BUG
#define HAVE_ARCH_BUG #define HAVE_ARCH_BUG
...@@ -73,15 +73,16 @@ do { \ ...@@ -73,15 +73,16 @@ do { \
unlikely(__ret_warn_on); \ unlikely(__ret_warn_on); \
}) })
#define UNWINDER_BUG() \ #define UNWINDER_BUG() \
do { \ do { \
__asm__ __volatile__ ( \ __asm__ __volatile__ ( \
"1:\t.short %O0\n" \ "1:\t.short %O0\n" \
_EMIT_BUG_ENTRY \ _EMIT_BUG_ENTRY \
: \ : \
: "n" (TRAPA_UNWINDER_BUG_OPCODE), \ : "n" (TRAPA_BUG_OPCODE), \
"i" (__FILE__), \ "i" (__FILE__), \
"i" (__LINE__), "i" (0), \ "i" (__LINE__), \
"i" (BUGFLAG_UNWINDER), \
"i" (sizeof(struct bug_entry))); \ "i" (sizeof(struct bug_entry))); \
} while (0) } while (0)
......
...@@ -19,10 +19,6 @@ ...@@ -19,10 +19,6 @@
#if !defined(CONFIG_SH_STANDARD_BIOS) #if !defined(CONFIG_SH_STANDARD_BIOS)
#define sh_bios_handler debug_trap_handler #define sh_bios_handler debug_trap_handler
#endif
#if !defined(CONFIG_DWARF_UNWINDER)
#define unwinder_trap_handler debug_trap_handler
#endif #endif
.data .data
...@@ -39,7 +35,7 @@ ENTRY(debug_trap_table) ...@@ -39,7 +35,7 @@ ENTRY(debug_trap_table)
.long debug_trap_handler /* 0x38 */ .long debug_trap_handler /* 0x38 */
.long debug_trap_handler /* 0x39 */ .long debug_trap_handler /* 0x39 */
.long debug_trap_handler /* 0x3a */ .long debug_trap_handler /* 0x3a */
.long unwinder_trap_handler /* 0x3b */ .long debug_trap_handler /* 0x3b */
.long breakpoint_trap_handler /* 0x3c */ .long breakpoint_trap_handler /* 0x3c */
.long singlestep_trap_handler /* 0x3d */ .long singlestep_trap_handler /* 0x3d */
.long bug_trap_handler /* 0x3e */ .long bug_trap_handler /* 0x3e */
......
...@@ -5,18 +5,32 @@ ...@@ -5,18 +5,32 @@
#include <linux/signal.h> #include <linux/signal.h>
#include <linux/sched.h> #include <linux/sched.h>
#include <linux/uaccess.h> #include <linux/uaccess.h>
#include <asm/unwinder.h>
#include <asm/system.h> #include <asm/system.h>
#ifdef CONFIG_BUG #ifdef CONFIG_BUG
void handle_BUG(struct pt_regs *regs) void handle_BUG(struct pt_regs *regs)
{ {
const struct bug_entry *bug;
unsigned long bugaddr = regs->pc;
enum bug_trap_type tt; 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) { if (tt == BUG_TRAP_TYPE_WARN) {
regs->pc += instruction_size(regs->pc); regs->pc += instruction_size(bugaddr);
return; return;
} }
invalid:
die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff); die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
} }
...@@ -28,8 +42,7 @@ int is_valid_bugaddr(unsigned long addr) ...@@ -28,8 +42,7 @@ int is_valid_bugaddr(unsigned long addr)
return 0; return 0;
if (probe_kernel_address((insn_size_t *)addr, opcode)) if (probe_kernel_address((insn_size_t *)addr, opcode))
return 0; return 0;
if (opcode == TRAPA_BUG_OPCODE)
if (opcode == TRAPA_BUG_OPCODE || opcode == TRAPA_UNWINDER_BUG_OPCODE)
return 1; return 1;
return 0; return 0;
......
...@@ -161,25 +161,4 @@ void unwind_stack(struct task_struct *task, struct pt_regs *regs, ...@@ -161,25 +161,4 @@ void unwind_stack(struct task_struct *task, struct pt_regs *regs,
curr_unwinder->dump(task, regs, sp, ops, data); 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); EXPORT_SYMBOL_GPL(unwind_stack);
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment