freebsd-skq/sys/alpha/alpha/db_trace.c
jhb f239fd4894 Fix last commit so that it actually works:
- Get test for valid trace request contents right.
- You don't use 'stq' to move a value from one register to another,
  use 'mov' to read sp.  Also, can't use nice names for registers
  in in-line asm in gcc.
- pc is not a publically accessible register, instead, create a label
  in the asm code and use 'lda' to load the address of that label into
  the pc field of the trace request.
- Use correction function name for db_print_backtrace().
2002-09-19 20:40:26 +00:00

430 lines
11 KiB
C

/* $FreeBSD$ */
/* $NetBSD: db_trace.c,v 1.9 2000/12/13 03:16:36 mycroft Exp $ */
/*-
* Copyright (c) 1999 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Ross Harvey.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
/*__KERNEL_RCSID(0, "$NetBSD: db_trace.c,v 1.9 2000/12/13 03:16:36 mycroft Exp $");*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/sysent.h>
#include <machine/db_machdep.h>
#include <ddb/ddb.h>
#include <ddb/db_sym.h>
#include <ddb/db_access.h>
#include <ddb/db_variables.h>
#include <ddb/db_output.h>
#include <alpha/alpha/db_instruction.h>
struct trace_request {
register_t ksp;
register_t pc;
};
/*
* Information about the `standard' Alpha function prologue.
*/
struct prologue_info {
int pi_reg_offset[32]; /* offset of registers in stack frame */
u_int32_t pi_regmask; /* which registers are in frame */
int pi_frame_size; /* frame size */
};
/*
* We use several symbols to take special action:
*
* Trap vectors, which use a different (fixed-size) stack frame:
*
* XentArith
* XentIF
* XentInt
* XentMM
* XentSys
* XentUna
*/
static struct special_symbol {
uintptr_t ss_val;
const char *ss_note;
} special_symbols[] = {
{ (uintptr_t)&XentArith, "arithmetic trap" },
{ (uintptr_t)&XentIF, "instruction fault" },
{ (uintptr_t)&XentInt, "interrupt" },
{ (uintptr_t)&XentMM, "memory management fault" },
{ (uintptr_t)&XentSys, "syscall" },
{ (uintptr_t)&XentUna, "unaligned access fault" },
{ (uintptr_t)&XentRestart, "console restart" },
{ NULL }
};
int db_md_set_watchpoint(db_expr_t addr, db_expr_t size);
int db_md_clr_watchpoint(db_expr_t addr, db_expr_t size);
void db_md_list_watchpoints(void);
/*
* Decode the function prologue for the function we're in, and note
* which registers are stored where, and how large the stack frame is.
*/
static void
decode_prologue(db_addr_t callpc, db_addr_t func,
struct prologue_info *pi)
{
long signed_immediate;
alpha_instruction ins;
db_expr_t pc;
pi->pi_regmask = 0;
pi->pi_frame_size = 0;
#define CHECK_FRAMESIZE \
do { \
if (pi->pi_frame_size != 0) { \
db_printf("frame size botch: adjust register offsets?\n"); \
} \
} while (0)
for (pc = func; pc < callpc; pc += sizeof(alpha_instruction)) {
ins.bits = *(unsigned int *)pc;
if (ins.memory_format.opcode == op_lda &&
ins.memory_format.ra == 30 &&
ins.memory_format.rb == 30) {
/*
* GCC 2.7-style stack adjust:
*
* lda sp, -64(sp)
*/
signed_immediate = (long)ins.mem_format.displacement;
#if 1
if (signed_immediate > 0)
db_printf("prologue botch: displacement %ld\n",
signed_immediate);
#endif
CHECK_FRAMESIZE;
pi->pi_frame_size += -signed_immediate;
} else if (ins.operate_lit_format.opcode == op_arit &&
ins.operate_lit_format.function == op_subq &&
ins.operate_lit_format.rs == 30 &&
ins.operate_lit_format.rd == 30) {
/*
* EGCS-style stack adjust:
*
* subq sp, 64, sp
*/
CHECK_FRAMESIZE;
pi->pi_frame_size += ins.operate_lit_format.literal;
} else if (ins.mem_format.opcode == op_stq &&
ins.mem_format.rs == 30 &&
ins.mem_format.rd != 31) {
/* Store of (non-zero) register onto the stack. */
signed_immediate = (long)ins.mem_format.displacement;
pi->pi_regmask |= 1 << ins.mem_format.rd;
pi->pi_reg_offset[ins.mem_format.rd] = signed_immediate;
}
}
}
static int
sym_is_trapsymbol(uintptr_t v)
{
int i;
for (i = 0; special_symbols[i].ss_val != NULL; ++i)
if (v == special_symbols[i].ss_val)
return 1;
return 0;
}
static void
decode_syscall(int number, struct proc *p)
{
c_db_sym_t sym;
db_expr_t diff;
sy_call_t *f;
const char *symname;
db_printf(" (%d", number);
if (p != NULL && 0 <= number && number < p->p_sysent->sv_size) {
f = p->p_sysent->sv_table[number].sy_call;
sym = db_search_symbol((db_addr_t)f, DB_STGY_ANY, &diff);
if (sym != DB_SYM_NULL && diff == 0) {
db_symbol_values(sym, &symname, NULL);
db_printf(", %s, %s", p->p_sysent->sv_name, symname);
}
}
db_printf(")");
}
void
db_stack_trace_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count, char *modif)
{
db_addr_t callpc = 0, frame = 0, symval;
struct prologue_info pi;
db_expr_t diff;
c_db_sym_t sym;
int i;
u_long tfps;
const char *symname;
struct pcb *pcbp;
struct trapframe *tf = NULL;
boolean_t ra_from_tf = FALSE;
boolean_t ra_from_pcb;
u_long last_ipl = ~0L;
struct proc *p = NULL;
struct thread *td = NULL;
boolean_t have_trapframe = FALSE;
pid_t pid;
if (count == -1)
count = 65535;
if (!have_addr) {
td = curthread;
p = td->td_proc;
addr = DDB_REGS->tf_regs[FRAME_SP] - FRAME_SIZE * 8;
tf = (struct trapframe *)addr;
have_trapframe = 1;
} else if (addr < KERNBASE) {
pid = (addr % 16) + ((addr >> 4) % 16) * 10 +
((addr >> 8) % 16) * 100 + ((addr >> 12) % 16) * 1000 +
((addr >> 16) % 16) * 10000;
/*
* The pcb for curproc is not valid at this point,
* so fall back to the default case.
*/
if (pid == curthread->td_proc->p_pid) {
td = curthread;
p = td->td_proc;
addr = DDB_REGS->tf_regs[FRAME_SP] - FRAME_SIZE * 8;
tf = (struct trapframe *)addr;
have_trapframe = 1;
} else {
/* sx_slock(&allproc_lock); */
LIST_FOREACH(p, &allproc, p_list) {
if (p->p_pid == pid)
break;
}
/* sx_sunlock(&allproc_lock); */
if (p == NULL) {
db_printf("pid %d not found\n", pid);
return;
}
if ((p->p_sflag & PS_INMEM) == 0) {
db_printf("pid %d swapped out\n", pid);
return;
}
pcbp = FIRST_THREAD_IN_PROC(p)->td_pcb; /* XXXKSE */
addr = (db_expr_t)pcbp->pcb_hw.apcb_ksp;
callpc = pcbp->pcb_context[7];
frame = addr;
}
} else {
struct trace_request *tr;
tr = (struct trace_request *)addr;
if (tr->ksp < KERNBASE || tr->pc < KERNBASE) {
db_printf("alpha trace requires known PC =eject=\n");
return;
}
callpc = tr->pc;
addr = tr->ksp;
frame = addr;
}
while (count--) {
if (have_trapframe) {
frame = (db_addr_t)tf + FRAME_SIZE * 8;
callpc = tf->tf_regs[FRAME_PC];
ra_from_tf = TRUE;
have_trapframe = 0;
}
sym = db_search_symbol(callpc, DB_STGY_ANY, &diff);
if (sym == DB_SYM_NULL)
break;
db_symbol_values(sym, &symname, (db_expr_t *)&symval);
if (callpc < symval) {
db_printf("symbol botch: callpc 0x%lx < "
"func 0x%lx (%s)\n", callpc, symval, symname);
return;
}
/*
* XXX Printing out arguments is Hard. We'd have to
* keep lots of state as we traverse the frame, figuring
* out where the arguments to the function are stored
* on the stack.
*
* Even worse, they may be stored to the stack _after_
* being modified in place; arguments are passed in
* registers.
*
* So, in order for this to work reliably, we pretty much
* have to have a kernel built with `cc -g':
*
* - The debugging symbols would tell us where the
* arguments are, how many there are, if there were
* any passed on the stack, etc.
*
* - Presumably, the compiler would be careful to
* store the argument registers on the stack before
* modifying the registers, so that a debugger could
* know what those values were upon procedure entry.
*
* Because of this, we don't bother. We've got most of the
* benefit of back tracking without the arguments, and we
* could get the arguments if we use a remote source-level
* debugger (for serious debugging).
*/
db_printf("%s() at ", symname);
db_printsym(callpc, DB_STGY_PROC);
db_printf("\n");
/*
* If we are in a trap vector, frame points to a
* trapframe.
*/
if (sym_is_trapsymbol(symval)) {
tf = (struct trapframe *)frame;
for (i = 0; special_symbols[i].ss_val != NULL; ++i)
if (symval == special_symbols[i].ss_val)
db_printf("--- %s",
special_symbols[i].ss_note);
tfps = tf->tf_regs[FRAME_PS];
if (symval == (uintptr_t)&XentSys)
decode_syscall(tf->tf_regs[FRAME_V0], p);
if ((tfps & ALPHA_PSL_IPL_MASK) != last_ipl) {
last_ipl = tfps & ALPHA_PSL_IPL_MASK;
if (symval != (uintptr_t)&XentSys)
db_printf(" (from ipl %ld)", last_ipl);
}
db_printf(" ---\n");
if (tfps & ALPHA_PSL_USERMODE) {
db_printf("--- user mode ---\n");
break; /* Terminate search. */
}
have_trapframe = 1;
continue;
}
/*
* This is a bit trickier; we must decode the function
* prologue to find the saved RA.
*
* XXX How does this interact w/ alloca()?!
*/
decode_prologue(callpc, symval, &pi);
if ((pi.pi_regmask & (1 << 26)) == 0) {
/*
* No saved RA found. We might have RA from
* the trap frame, however (e.g trap occurred
* in a leaf call). If not, we've found the
* root of the call graph.
*/
if (ra_from_tf)
callpc = tf->tf_regs[FRAME_RA];
else {
db_printf("--- root of call graph ---\n");
break;
}
} else
callpc = *(u_long *)(frame + pi.pi_reg_offset[26]);
ra_from_tf = ra_from_pcb = FALSE;
#if 0
/*
* The call was actually made at RA - 4; the PC is
* updated before being stored in RA.
*/
callpc -= 4;
#endif
frame += pi.pi_frame_size;
}
}
void
db_print_backtrace(void)
{
struct trace_request tr;
__asm __volatile(
" mov $30,%0 \n"
" lda %1,1f \n"
"1:\n"
: "=r" (tr.ksp), "=r" (tr.pc));
db_stack_trace_cmd((db_addr_t)&tr, 1, -1, NULL);
}
int
db_md_set_watchpoint(addr, size)
db_expr_t addr;
db_expr_t size;
{
return (-1);
}
int
db_md_clr_watchpoint(addr, size)
db_expr_t addr;
db_expr_t size;
{
return (-1);
}
void
db_md_list_watchpoints()
{
return;
}