/*- * Mach Operating System * Copyright (c) 1991,1990 Carnegie Mellon University * All Rights Reserved. * * Permission to use, copy, modify and distribute this software and its * documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static db_varfcn_t db_esp; static db_varfcn_t db_frame; static db_varfcn_t db_frame_seg; static db_varfcn_t db_gs; static db_varfcn_t db_ss; /* * Machine register set. */ #define DB_OFFSET(x) (db_expr_t *)offsetof(struct trapframe, x) struct db_variable db_regs[] = { { "cs", DB_OFFSET(tf_cs), db_frame_seg }, { "ds", DB_OFFSET(tf_ds), db_frame_seg }, { "es", DB_OFFSET(tf_es), db_frame_seg }, { "fs", DB_OFFSET(tf_fs), db_frame_seg }, { "gs", NULL, db_gs }, { "ss", NULL, db_ss }, { "eax", DB_OFFSET(tf_eax), db_frame }, { "ecx", DB_OFFSET(tf_ecx), db_frame }, { "edx", DB_OFFSET(tf_edx), db_frame }, { "ebx", DB_OFFSET(tf_ebx), db_frame }, { "esp", NULL, db_esp }, { "ebp", DB_OFFSET(tf_ebp), db_frame }, { "esi", DB_OFFSET(tf_esi), db_frame }, { "edi", DB_OFFSET(tf_edi), db_frame }, { "eip", DB_OFFSET(tf_eip), db_frame }, { "efl", DB_OFFSET(tf_eflags), db_frame }, }; struct db_variable *db_eregs = db_regs + nitems(db_regs); static __inline int get_esp(struct trapframe *tf) { return (TF_HAS_STACKREGS(tf) ? tf->tf_esp : (intptr_t)&tf->tf_esp); } static int db_frame(struct db_variable *vp, db_expr_t *valuep, int op) { int *reg; if (kdb_frame == NULL) return (0); reg = (int *)((uintptr_t)kdb_frame + (db_expr_t)vp->valuep); if (op == DB_VAR_GET) *valuep = *reg; else *reg = *valuep; return (1); } static int db_frame_seg(struct db_variable *vp, db_expr_t *valuep, int op) { struct trapframe_vm86 *tfp; int off; uint16_t *reg; if (kdb_frame == NULL) return (0); off = (intptr_t)vp->valuep; if (kdb_frame->tf_eflags & PSL_VM) { tfp = (void *)kdb_frame; switch ((intptr_t)vp->valuep) { case (intptr_t)DB_OFFSET(tf_cs): reg = (uint16_t *)&tfp->tf_cs; break; case (intptr_t)DB_OFFSET(tf_ds): reg = (uint16_t *)&tfp->tf_vm86_ds; break; case (intptr_t)DB_OFFSET(tf_es): reg = (uint16_t *)&tfp->tf_vm86_es; break; case (intptr_t)DB_OFFSET(tf_fs): reg = (uint16_t *)&tfp->tf_vm86_fs; break; } } else reg = (uint16_t *)((uintptr_t)kdb_frame + off); if (op == DB_VAR_GET) *valuep = *reg; else *reg = *valuep; return (1); } static int db_esp(struct db_variable *vp, db_expr_t *valuep, int op) { if (kdb_frame == NULL) return (0); if (op == DB_VAR_GET) *valuep = get_esp(kdb_frame); else if (TF_HAS_STACKREGS(kdb_frame)) kdb_frame->tf_esp = *valuep; return (1); } static int db_gs(struct db_variable *vp, db_expr_t *valuep, int op) { struct trapframe_vm86 *tfp; if (kdb_frame != NULL && kdb_frame->tf_eflags & PSL_VM) { tfp = (void *)kdb_frame; if (op == DB_VAR_GET) *valuep = tfp->tf_vm86_gs; else tfp->tf_vm86_gs = *valuep; return (1); } if (op == DB_VAR_GET) *valuep = rgs(); else load_gs(*valuep); return (1); } static int db_ss(struct db_variable *vp, db_expr_t *valuep, int op) { if (kdb_frame == NULL) return (0); if (op == DB_VAR_GET) *valuep = TF_HAS_STACKREGS(kdb_frame) ? kdb_frame->tf_ss : rss(); else if (TF_HAS_STACKREGS(kdb_frame)) kdb_frame->tf_ss = *valuep; return (1); } #define NORMAL 0 #define TRAP 1 #define INTERRUPT 2 #define SYSCALL 3 #define DOUBLE_FAULT 4 #define TRAP_INTERRUPT 5 #define TRAP_TIMERINT 6 static void db_nextframe(struct i386_frame **, db_addr_t *, struct thread *); static int db_numargs(struct i386_frame *); static void db_print_stack_entry(const char *, int, char **, int *, db_addr_t, void *); static void decode_syscall(int, struct thread *); static const char * watchtype_str(int type); int i386_set_watch(int watchnum, unsigned int watchaddr, int size, int access, struct dbreg *d); int i386_clr_watch(int watchnum, struct dbreg *d); /* * Figure out how many arguments were passed into the frame at "fp". */ static int db_numargs(fp) struct i386_frame *fp; { char *argp; int inst; int args; argp = (char *)db_get_value((int)&fp->f_retaddr, 4, FALSE); /* * XXX etext is wrong for LKMs. We should attempt to interpret * the instruction at the return address in all cases. This * may require better fault handling. */ if (argp < btext || argp >= etext) { args = -1; } else { retry: inst = db_get_value((int)argp, 4, FALSE); if ((inst & 0xff) == 0x59) /* popl %ecx */ args = 1; else if ((inst & 0xffff) == 0xc483) /* addl $Ibs, %esp */ args = ((inst >> 16) & 0xff) / 4; else if ((inst & 0xf8ff) == 0xc089) { /* movl %eax, %Reg */ argp += 2; goto retry; } else args = -1; } return (args); } static void db_print_stack_entry(name, narg, argnp, argp, callpc, frame) const char *name; int narg; char **argnp; int *argp; db_addr_t callpc; void *frame; { int n = narg >= 0 ? narg : 5; db_printf("%s(", name); while (n) { if (argnp) db_printf("%s=", *argnp++); db_printf("%r", db_get_value((int)argp, 4, FALSE)); argp++; if (--n != 0) db_printf(","); } if (narg < 0) db_printf(",..."); db_printf(") at "); db_printsym(callpc, DB_STGY_PROC); if (frame != NULL) db_printf("/frame 0x%r", (register_t)frame); db_printf("\n"); } static void decode_syscall(int number, struct thread *td) { struct proc *p; c_db_sym_t sym; db_expr_t diff; sy_call_t *f; const char *symname; db_printf(" (%d", number); p = (td != NULL) ? td->td_proc : NULL; 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(")"); } /* * Figure out the next frame up in the call stack. */ static void db_nextframe(struct i386_frame **fp, db_addr_t *ip, struct thread *td) { struct trapframe *tf; int frame_type; int eip, esp, ebp; db_expr_t offset; c_db_sym_t sym; const char *name; eip = db_get_value((int) &(*fp)->f_retaddr, 4, FALSE); ebp = db_get_value((int) &(*fp)->f_frame, 4, FALSE); /* * Figure out frame type. We look at the address just before * the saved instruction pointer as the saved EIP is after the * call function, and if the function being called is marked as * dead (such as panic() at the end of dblfault_handler()), then * the instruction at the saved EIP will be part of a different * function (syscall() in this example) rather than the one that * actually made the call. */ frame_type = NORMAL; sym = db_search_symbol(eip - 1, DB_STGY_ANY, &offset); db_symbol_values(sym, &name, NULL); if (name != NULL) { if (strcmp(name, "calltrap") == 0 || strcmp(name, "fork_trampoline") == 0) frame_type = TRAP; else if (strncmp(name, "Xatpic_intr", 11) == 0 || strncmp(name, "Xapic_isr", 9) == 0) frame_type = INTERRUPT; else if (strcmp(name, "Xlcall_syscall") == 0 || strcmp(name, "Xint0x80_syscall") == 0) frame_type = SYSCALL; else if (strcmp(name, "dblfault_handler") == 0) frame_type = DOUBLE_FAULT; /* XXX: These are interrupts with trap frames. */ else if (strcmp(name, "Xtimerint") == 0) frame_type = TRAP_TIMERINT; else if (strcmp(name, "Xcpustop") == 0 || strcmp(name, "Xrendezvous") == 0 || strcmp(name, "Xipi_intr_bitmap_handler") == 0) frame_type = TRAP_INTERRUPT; } /* * Normal frames need no special processing. */ if (frame_type == NORMAL) { *ip = (db_addr_t) eip; *fp = (struct i386_frame *) ebp; return; } db_print_stack_entry(name, 0, 0, 0, eip, &(*fp)->f_frame); /* * For a double fault, we have to snag the values from the * previous TSS since a double fault uses a task gate to * switch to a known good state. */ if (frame_type == DOUBLE_FAULT) { esp = PCPU_GET(common_tss.tss_esp); eip = PCPU_GET(common_tss.tss_eip); ebp = PCPU_GET(common_tss.tss_ebp); db_printf( "--- trap 0x17, eip = %#r, esp = %#r, ebp = %#r ---\n", eip, esp, ebp); *ip = (db_addr_t) eip; *fp = (struct i386_frame *) ebp; return; } /* * Point to base of trapframe which is just above the * current frame. */ if (frame_type == INTERRUPT) tf = (struct trapframe *)((int)*fp + 16); else if (frame_type == TRAP_INTERRUPT) tf = (struct trapframe *)((int)*fp + 8); else tf = (struct trapframe *)((int)*fp + 12); if (INKERNEL((int) tf)) { esp = get_esp(tf); eip = tf->tf_eip; ebp = tf->tf_ebp; switch (frame_type) { case TRAP: db_printf("--- trap %#r", tf->tf_trapno); break; case SYSCALL: db_printf("--- syscall"); decode_syscall(tf->tf_eax, td); break; case TRAP_TIMERINT: case TRAP_INTERRUPT: case INTERRUPT: db_printf("--- interrupt"); break; default: panic("The moon has moved again."); } db_printf(", eip = %#r, esp = %#r, ebp = %#r ---\n", eip, esp, ebp); } *ip = (db_addr_t) eip; *fp = (struct i386_frame *) ebp; } static int db_backtrace(struct thread *td, struct trapframe *tf, struct i386_frame *frame, db_addr_t pc, register_t sp, int count) { struct i386_frame *actframe; #define MAXNARG 16 char *argnames[MAXNARG], **argnp = NULL; const char *name; int *argp; db_expr_t offset; c_db_sym_t sym; int instr, narg; boolean_t first; if (db_segsize(tf) == 16) { db_printf( "--- 16-bit%s, cs:eip = %#x:%#x, ss:esp = %#x:%#x, ebp = %#x, tf = %p ---\n", (tf->tf_eflags & PSL_VM) ? " (vm86)" : "", tf->tf_cs, tf->tf_eip, TF_HAS_STACKREGS(tf) ? tf->tf_ss : rss(), TF_HAS_STACKREGS(tf) ? tf->tf_esp : (intptr_t)&tf->tf_esp, tf->tf_ebp, tf); return (0); } /* * If an indirect call via an invalid pointer caused a trap, * %pc contains the invalid address while the return address * of the unlucky caller has been saved by CPU on the stack * just before the trap frame. In this case, try to recover * the caller's address so that the first frame is assigned * to the right spot in the right function, for that is where * the failure actually happened. * * This trick depends on the fault address stashed in tf_err * by trap_fatal() before entering KDB. */ if (kdb_frame && pc == kdb_frame->tf_err) { /* * Find where the trap frame actually ends. * It won't contain tf_esp or tf_ss unless crossing rings. */ if (TF_HAS_STACKREGS(kdb_frame)) instr = (int)(kdb_frame + 1); else instr = (int)&kdb_frame->tf_esp; pc = db_get_value(instr, 4, FALSE); } if (count == -1) count = 1024; first = TRUE; while (count-- && !db_pager_quit) { sym = db_search_symbol(pc, DB_STGY_ANY, &offset); db_symbol_values(sym, &name, NULL); /* * Attempt to determine a (possibly fake) frame that gives * the caller's pc. It may differ from `frame' if the * current function never sets up a standard frame or hasn't * set one up yet or has just discarded one. The last two * cases can be guessed fairly reliably for code generated * by gcc. The first case is too much trouble to handle in * general because the amount of junk on the stack depends * on the pc (the special handling of "calltrap", etc. in * db_nextframe() works because the `next' pc is special). */ actframe = frame; if (first) { first = FALSE; if (sym == C_DB_SYM_NULL && sp != 0) { /* * If a symbol couldn't be found, we've probably * jumped to a bogus location, so try and use * the return address to find our caller. */ db_print_stack_entry(name, 0, 0, 0, pc, NULL); pc = db_get_value(sp, 4, FALSE); if (db_search_symbol(pc, DB_STGY_PROC, &offset) == C_DB_SYM_NULL) break; continue; } else if (tf != NULL) { instr = db_get_value(pc, 4, FALSE); if ((instr & 0xffffff) == 0x00e58955) { /* pushl %ebp; movl %esp, %ebp */ actframe = (void *)(get_esp(tf) - 4); } else if ((instr & 0xffff) == 0x0000e589) { /* movl %esp, %ebp */ actframe = (void *)get_esp(tf); if (tf->tf_ebp == 0) { /* Fake frame better. */ frame = actframe; } } else if ((instr & 0xff) == 0x000000c3) { /* ret */ actframe = (void *)(get_esp(tf) - 4); } else if (offset == 0) { /* Probably an assembler symbol. */ actframe = (void *)(get_esp(tf) - 4); } } else if (strcmp(name, "fork_trampoline") == 0) { /* * Don't try to walk back on a stack for a * process that hasn't actually been run yet. */ db_print_stack_entry(name, 0, 0, 0, pc, actframe); break; } } argp = &actframe->f_arg0; narg = MAXNARG; if (sym != NULL && db_sym_numargs(sym, &narg, argnames)) { argnp = argnames; } else { narg = db_numargs(frame); } db_print_stack_entry(name, narg, argnp, argp, pc, actframe); if (actframe != frame) { /* `frame' belongs to caller. */ pc = (db_addr_t) db_get_value((int)&actframe->f_retaddr, 4, FALSE); continue; } db_nextframe(&frame, &pc, td); if (INKERNEL((int)pc) && !INKERNEL((int) frame)) { sym = db_search_symbol(pc, DB_STGY_ANY, &offset); db_symbol_values(sym, &name, NULL); db_print_stack_entry(name, 0, 0, 0, pc, frame); break; } if (!INKERNEL((int) frame)) { break; } } return (0); } void db_trace_self(void) { struct i386_frame *frame; db_addr_t callpc; register_t ebp; __asm __volatile("movl %%ebp,%0" : "=r" (ebp)); frame = (struct i386_frame *)ebp; callpc = (db_addr_t)db_get_value((int)&frame->f_retaddr, 4, FALSE); frame = frame->f_frame; db_backtrace(curthread, NULL, frame, callpc, 0, -1); } int db_trace_thread(struct thread *thr, int count) { struct pcb *ctx; struct trapframe *tf; ctx = kdb_thr_ctx(thr); tf = thr == kdb_thread ? kdb_frame : NULL; return (db_backtrace(thr, tf, (struct i386_frame *)ctx->pcb_ebp, ctx->pcb_eip, ctx->pcb_esp, count)); } int i386_set_watch(watchnum, watchaddr, size, access, d) int watchnum; unsigned int watchaddr; int size; int access; struct dbreg *d; { int i, len; if (watchnum == -1) { for (i = 0; i < 4; i++) if (!DBREG_DR7_ENABLED(d->dr[7], i)) break; if (i < 4) watchnum = i; else return (-1); } switch (access) { case DBREG_DR7_EXEC: size = 1; /* size must be 1 for an execution breakpoint */ /* fall through */ case DBREG_DR7_WRONLY: case DBREG_DR7_RDWR: break; default: return (-1); } /* * we can watch a 1, 2, or 4 byte sized location */ switch (size) { case 1: len = DBREG_DR7_LEN_1; break; case 2: len = DBREG_DR7_LEN_2; break; case 4: len = DBREG_DR7_LEN_4; break; default: return (-1); } /* clear the bits we are about to affect */ d->dr[7] &= ~DBREG_DR7_MASK(watchnum); /* set drN register to the address, N=watchnum */ DBREG_DRX(d, watchnum) = watchaddr; /* enable the watchpoint */ d->dr[7] |= DBREG_DR7_SET(watchnum, len, access, DBREG_DR7_GLOBAL_ENABLE); return (watchnum); } int i386_clr_watch(watchnum, d) int watchnum; struct dbreg *d; { if (watchnum < 0 || watchnum >= 4) return (-1); d->dr[7] &= ~DBREG_DR7_MASK(watchnum); DBREG_DRX(d, watchnum) = 0; return (0); } int db_md_set_watchpoint(addr, size) db_expr_t addr; db_expr_t size; { struct dbreg d; int avail, i, wsize; fill_dbregs(NULL, &d); avail = 0; for(i = 0; i < 4; i++) { if (!DBREG_DR7_ENABLED(d.dr[7], i)) avail++; } if (avail * 4 < size) return (-1); for (i = 0; i < 4 && (size > 0); i++) { if (!DBREG_DR7_ENABLED(d.dr[7], i)) { if (size > 2) wsize = 4; else wsize = size; i386_set_watch(i, addr, wsize, DBREG_DR7_WRONLY, &d); addr += wsize; size -= wsize; } } set_dbregs(NULL, &d); return(0); } int db_md_clr_watchpoint(addr, size) db_expr_t addr; db_expr_t size; { struct dbreg d; int i; fill_dbregs(NULL, &d); for(i = 0; i < 4; i++) { if (DBREG_DR7_ENABLED(d.dr[7], i)) { if ((DBREG_DRX((&d), i) >= addr) && (DBREG_DRX((&d), i) < addr+size)) i386_clr_watch(i, &d); } } set_dbregs(NULL, &d); return(0); } static const char * watchtype_str(type) int type; { switch (type) { case DBREG_DR7_EXEC : return "execute"; break; case DBREG_DR7_RDWR : return "read/write"; break; case DBREG_DR7_WRONLY : return "write"; break; default : return "invalid"; break; } } void db_md_list_watchpoints() { struct dbreg d; int i, len, type; fill_dbregs(NULL, &d); db_printf("\nhardware watchpoints:\n"); db_printf(" watch status type len address\n"); db_printf(" ----- -------- ---------- --- ----------\n"); for (i = 0; i < 4; i++) { if (DBREG_DR7_ENABLED(d.dr[7], i)) { type = DBREG_DR7_ACCESS(d.dr[7], i); len = DBREG_DR7_LEN(d.dr[7], i); db_printf(" %-5d %-8s %10s %3d ", i, "enabled", watchtype_str(type), len + 1); db_printsym((db_addr_t)DBREG_DRX((&d), i), DB_STGY_ANY); db_printf("\n"); } else { db_printf(" %-5d disabled\n", i); } } db_printf("\ndebug register values:\n"); for (i = 0; i < 8; i++) { db_printf(" dr%d 0x%08x\n", i, DBREG_DRX((&d), i)); } db_printf("\n"); }