static int
kdb_ss(int argc, const char **argv)
{
int ssb = 0;
struct pt_regs *regs = get_irq_regs();
ssb = (strcmp(argv[0], "ssb") == 0);
if (argc != 0)
return KDB_ARGCOUNT;
if (!regs) {
kdb_printf("%s: pt_regs not available\n", __FUNCTION__);
return KDB_BADREG;
}
/*
* Set trace flag and go.
*/
KDB_STATE_SET(DOING_SS);
if (ssb)
KDB_STATE_SET(DOING_SSB);
kdba_setsinglestep(regs); /* Enable single step */
if (ssb)
return KDB_CMD_SSB;
return KDB_CMD_SS;
}
kdb_dbtrap_t
kdba_bp_trap(struct pt_regs *regs, int error_unused)
{
int i;
kdb_dbtrap_t rv;
kdb_bp_t *bp;
if (KDB_NULL_REGS(regs))
return KDB_DB_NOBPT;
/*
* Determine which breakpoint was encountered.
*/
if (KDB_DEBUG(BP))
kdb_printf("kdba_bp_trap: rip=0x%lx (not adjusted) "
"eflags=0x%lx ef=0x%p rsp=0x%lx\n",
regs->rip, regs->eflags, regs, regs->rsp);
rv = KDB_DB_NOBPT; /* Cause kdb() to return */
for(i=0, bp=kdb_breakpoints; i<KDB_MAXBPT; i++, bp++) {
if (bp->bp_free)
continue;
if (!bp->bp_global && bp->bp_cpu != smp_processor_id())
continue;
if ((void *)bp->bp_addr == (void *)(regs->rip - bp->bp_adjust)) {
/* Hit this breakpoint. */
regs->rip -= bp->bp_adjust;
kdb_printf("Instruction(i) breakpoint #%d at 0x%lx (adjusted)\n",
i, regs->rip);
kdb_id1(regs->rip);
rv = KDB_DB_BPT;
bp->bp_delay = 1;
/* SSBPT is set when the kernel debugger must single
* step a task in order to re-establish an instruction
* breakpoint which uses the instruction replacement
* mechanism. It is cleared by any action that removes
* the need to single-step the breakpoint.
*/
KDB_STATE_SET(SSBPT);
break;
}
}
return rv;
}
int kdb_stub(struct kgdb_state *ks)
{
int error = 0;
kdb_bp_t *bp;
unsigned long addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs);
kdb_reason_t reason = KDB_REASON_OOPS;
kdb_dbtrap_t db_result = KDB_DB_NOBPT;
int i;
if (KDB_STATE(REENTRY)) {
reason = KDB_REASON_SWITCH;
KDB_STATE_CLEAR(REENTRY);
addr = instruction_pointer(ks->linux_regs);
}
ks->pass_exception = 0;
if (atomic_read(&kgdb_setting_breakpoint))
reason = KDB_REASON_KEYBOARD;
for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
if ((bp->bp_enabled) && (bp->bp_addr == addr)) {
reason = KDB_REASON_BREAK;
db_result = KDB_DB_BPT;
if (addr != instruction_pointer(ks->linux_regs))
kgdb_arch_set_pc(ks->linux_regs, addr);
break;
}
}
if (reason == KDB_REASON_BREAK || reason == KDB_REASON_SWITCH) {
for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
if (bp->bp_free)
continue;
if (bp->bp_addr == addr) {
bp->bp_delay = 1;
bp->bp_delayed = 1;
/*
* SSBPT is set when the kernel debugger must single step a
* task in order to re-establish an instruction breakpoint
* which uses the instruction replacement mechanism. It is
* cleared by any action that removes the need to single-step
* the breakpoint.
*/
reason = KDB_REASON_BREAK;
db_result = KDB_DB_BPT;
KDB_STATE_SET(SSBPT);
break;
}
}
}
if (reason != KDB_REASON_BREAK && ks->ex_vector == 0 &&
ks->signo == SIGTRAP) {
reason = KDB_REASON_SSTEP;
db_result = KDB_DB_BPT;
}
/* Set initial kdb state variables */
KDB_STATE_CLEAR(KGDB_TRANS);
kdb_initial_cpu = ks->cpu;
kdb_current_task = kgdb_info[ks->cpu].task;
kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo;
/* Remove any breakpoints as needed by kdb and clear single step */
kdb_bp_remove();
KDB_STATE_CLEAR(DOING_SS);
KDB_STATE_CLEAR(DOING_SSB);
KDB_STATE_SET(PAGER);
/* zero out any offline cpu data */
for_each_present_cpu(i) {
if (!cpu_online(i)) {
kgdb_info[i].debuggerinfo = NULL;
kgdb_info[i].task = NULL;
}
}
if (ks->err_code == DIE_OOPS || reason == KDB_REASON_OOPS) {
ks->pass_exception = 1;
KDB_FLAG_SET(CATASTROPHIC);
}
kdb_initial_cpu = ks->cpu;
if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) {
KDB_STATE_CLEAR(SSBPT);
KDB_STATE_CLEAR(DOING_SS);
} else {
/* Start kdb main loop */
error = kdb_main_loop(KDB_REASON_ENTER, reason,
ks->err_code, db_result, ks->linux_regs);
}
/*
* Upon exit from the kdb main loop setup break points and restart
* the system based on the requested continue state
*/
kdb_initial_cpu = -1;
kdb_current_task = NULL;
kdb_current_regs = NULL;
KDB_STATE_CLEAR(PAGER);
kdbnearsym_cleanup();
if (error == KDB_CMD_KGDB) {
if (KDB_STATE(DOING_KGDB) || KDB_STATE(DOING_KGDB2)) {
/*
* This inteface glue which allows kdb to transition in into
* the gdb stub. In order to do this the '?' or '' gdb serial
* packet response is processed here. And then control is
* passed to the gdbstub.
*/
if (KDB_STATE(DOING_KGDB))
gdbstub_state(ks, "?");
else
gdbstub_state(ks, "");
KDB_STATE_CLEAR(DOING_KGDB);
KDB_STATE_CLEAR(DOING_KGDB2);
}
return DBG_PASS_EVENT;
}
kdb_bp_install(ks->linux_regs);
dbg_activate_sw_breakpoints();
/* Set the exit state to a single step or a continue */
if (KDB_STATE(DOING_SS))
gdbstub_state(ks, "s");
else
gdbstub_state(ks, "c");
KDB_FLAG_CLEAR(CATASTROPHIC);
/* Invoke arch specific exception handling prior to system resume */
kgdb_info[ks->cpu].ret_state = gdbstub_state(ks, "e");
if (ks->pass_exception)
kgdb_info[ks->cpu].ret_state = 1;
if (error == KDB_CMD_CPU) {
KDB_STATE_SET(REENTRY);
/*
* Force clear the single step bit because kdb emulates this
* differently vs the gdbstub
*/
kgdb_single_step = 0;
dbg_deactivate_sw_breakpoints();
return DBG_SWITCH_CPU_EVENT;
}
return kgdb_info[ks->cpu].ret_state;
}
static void kdb_setsinglestep(struct pt_regs *regs)
{
KDB_STATE_SET(DOING_SS);
}