android_kernel_xiaomi_sm8350/arch/sh/kernel/traps.c
Paul Mundt 9a33fc217d sh: Make is_valid_bugaddr() more intelligent on nommu.
Currently is_valid_bugaddr() is true for anything >= PAGE_OFFSET, which
happens to be 0 on nommu configurations. Make this a bit smarter by just
reading in the opcode and comparing it against the trap type that we
already know. Follows the logic from avr32.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-05-19 19:32:07 +09:00

77 lines
1.4 KiB
C

#include <linux/bug.h>
#include <linux/io.h>
#include <linux/types.h>
#include <linux/kdebug.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include <asm/system.h>
#ifdef CONFIG_BUG
static void handle_BUG(struct pt_regs *regs)
{
enum bug_trap_type tt;
tt = report_bug(regs->pc, regs);
if (tt == BUG_TRAP_TYPE_WARN) {
regs->pc += instruction_size(regs->pc);
return;
}
die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
}
int is_valid_bugaddr(unsigned long addr)
{
unsigned short opcode;
if (addr < PAGE_OFFSET)
return 0;
if (probe_kernel_address((u16 *)addr, opcode))
return 0;
return opcode == TRAPA_BUG_OPCODE;
}
#endif
/*
* Generic trap handler.
*/
BUILD_TRAP_HANDLER(debug)
{
TRAP_HANDLER_DECL;
/* Rewind */
regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff,
SIGTRAP) == NOTIFY_STOP)
return;
force_sig(SIGTRAP, current);
}
/*
* Special handler for BUG() traps.
*/
BUILD_TRAP_HANDLER(bug)
{
TRAP_HANDLER_DECL;
/* Rewind */
regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
SIGTRAP) == NOTIFY_STOP)
return;
#ifdef CONFIG_BUG
if (__kernel_text_address(instruction_pointer(regs))) {
opcode_t insn = *(opcode_t *)instruction_pointer(regs);
if (insn == TRAPA_BUG_OPCODE)
handle_BUG(regs);
}
#endif
force_sig(SIGTRAP, current);
}