1 /* Live and postmortem kernel debugging functions for FreeBSD.
2 Copyright 1996 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
20 /* $FreeBSD: src/gnu/usr.bin/binutils/gdb/i386/kvm-fbsd.c,v 1.17.4.3 2001/12/17 23:06:06 peter Exp $ */
28 #include <sys/sysctl.h>
29 #include <sys/param.h>
33 #include "frame.h" /* required by inferior.h */
45 #include <vm/vm_param.h>
47 #include <machine/vmparam.h>
48 #include <machine/pcb.h>
49 #include <machine/tss.h>
50 #include <machine/frame.h>
52 static void kcore_files_info PARAMS ((struct target_ops *));
54 static void kcore_close PARAMS ((int));
56 static void get_kcore_registers PARAMS ((int));
58 static int kcore_xfer_kmem PARAMS ((CORE_ADDR, char *, int, int, struct target_ops *));
60 static int xfer_umem PARAMS ((CORE_ADDR, char *, int, int));
62 static CORE_ADDR ksym_lookup PARAMS ((const char *));
64 static int read_pcb PARAMS ((int, CORE_ADDR));
66 static struct proc * curProc PARAMS ((void));
68 static int set_proc_context PARAMS ((CORE_ADDR paddr));
70 static void kcore_open PARAMS ((char *filename, int from_tty));
72 static void kcore_detach PARAMS ((char *args, int from_tty));
74 static void set_proc_cmd PARAMS ((char *arg, int from_tty));
76 static void set_cpu_cmd PARAMS ((char *arg, int from_tty));
78 static CORE_ADDR kvtophys PARAMS ((int, CORE_ADDR));
80 static int physrd PARAMS ((int, u_int, char*, int));
82 static int kvm_open PARAMS ((const char *efile, char *cfile, char *sfile,
83 int perm, char *errout));
85 static int kvm_close PARAMS ((int fd));
87 static int kvm_write PARAMS ((int core_kd, CORE_ADDR memaddr,
88 char *myaddr, int len));
90 static int kvm_read PARAMS ((int core_kd, CORE_ADDR memaddr,
91 char *myaddr, int len));
93 static int kvm_uread PARAMS ((int core_kd, struct proc *p,
94 CORE_ADDR memaddr, char *myaddr,
97 static int kernel_core_file_hook PARAMS ((int fd, CORE_ADDR addr,
100 static struct kinfo_proc * kvm_getprocs PARAMS ((int cfd, int op,
101 CORE_ADDR proc, int *cnt));
103 extern struct target_ops kcore_ops; /* Forward decl */
105 /* Non-zero means we are debugging a kernel core file */
106 int kernel_debugging = 0;
107 int kernel_writablecore = 0;
109 static char *core_file;
110 static int core_kd = -1;
111 static struct proc *cur_proc;
112 static CORE_ADDR kernel_start;
116 static CORE_ADDR prv_space; /* per-cpu private space */
117 static int prv_space_size;
118 #define prv_start (prv_space + cpuid * prv_space_size)
121 * Read the "thing" at kernel address 'addr' into the space pointed to
122 * by point. The length of the "thing" is determined by the type of p.
123 * Result is non-zero if transfer fails.
125 #define kvread(addr, p) \
126 (target_read_memory ((CORE_ADDR)(addr), (char *)(p), sizeof(*(p))))
131 * The following is FreeBSD-specific hackery to decode special frames
132 * and elide the assembly-language stub. This could be made faster by
133 * defining a frame_type field in the machine-dependent frame information,
134 * but we don't think that's too important right now.
136 enum frametype { tf_normal, tf_trap, tf_interrupt, tf_syscall };
139 fbsd_kern_frame_saved_pc (fr)
140 struct frame_info *fr;
142 struct minimal_symbol *sym;
143 CORE_ADDR this_saved_pc;
144 enum frametype frametype;
146 this_saved_pc = read_memory_integer (fr->frame + 4, 4);
147 sym = lookup_minimal_symbol_by_pc (this_saved_pc);
148 frametype = tf_normal;
150 if (strcmp (SYMBOL_NAME(sym), "calltrap") == 0)
152 else if (strncmp (SYMBOL_NAME(sym), "Xresume", 7) == 0)
153 frametype = tf_interrupt;
154 else if (strcmp (SYMBOL_NAME(sym), "Xsyscall") == 0)
155 frametype = tf_syscall;
160 return (this_saved_pc);
162 #define oEIP offsetof(struct trapframe, tf_eip)
165 return (read_memory_integer (fr->frame + 8 + oEIP, 4));
168 return (read_memory_integer (fr->frame + 16 + oEIP, 4));
171 return (read_memory_integer (fr->frame + 8 + oEIP, 4));
180 struct minimal_symbol *sym;
182 sym = lookup_minimal_symbol (name, NULL, NULL);
184 error ("kernel symbol `%s' not found.", name);
186 return SYMBOL_VALUE_ADDRESS (sym);
193 CORE_ADDR addr = ksym_lookup ("gd_curproc") + prv_start;
195 if (kvread (addr, &p))
196 error ("cannot read proc pointer at %x\n", addr);
201 * Set the process context to that of the proc structure at
202 * system address paddr.
205 set_proc_context (paddr)
210 if (paddr < kernel_start)
213 cur_proc = (struct proc *)paddr;
215 set_kernel_boundaries (cur_proc);
218 /* Fetch all registers from core file */
219 target_fetch_registers (-1);
221 /* Now, set up the frame cache, and print the top of stack */
222 flush_cached_frames ();
223 set_current_frame (create_new_frame (read_fp (), read_pc ()));
224 select_frame (get_current_frame (), 0);
228 /* Discard all vestiges of any previous core file
229 and mark data and stack spaces as empty. */
233 kcore_close (quitting)
236 inferior_pid = 0; /* Avoid confusion from thread stuff */
247 /* This routine opens and sets up the core file bfd */
250 kcore_open (filename, from_tty)
255 struct cleanup *old_chain;
261 target_preopen (from_tty);
263 unpush_target (&kcore_ops);
268 error ( (core_kd >= 0)?
269 "No core file specified. (Use `detach' to stop debugging a core file.)"
270 : "No core file specified.");
273 filename = tilde_expand (filename);
274 if (filename[0] != '/')
276 cp = concat (current_directory, "/", filename, NULL);
281 old_chain = make_cleanup (free, filename);
284 * gdb doesn't really do anything if the exec-file couldn't
285 * be opened (in that case exec_bfd is NULL). Usually that's
286 * no big deal, but kvm_open needs the exec-file's name,
287 * which results in dereferencing a NULL pointer, a real NO-NO !
288 * So, check here if the open of the exec-file succeeded.
290 if (exec_bfd == NULL) /* the open failed */
291 error ("kgdb could not open the exec-file, please check the name you used !");
293 core_kd = kvm_open (exec_bfd->filename, filename, NULL,
294 kernel_writablecore? O_RDWR : O_RDONLY, "kgdb: ");
296 perror_with_name (filename);
298 /* Looks semi-reasonable. Toss the old core file and work on the new. */
300 discard_cleanups (old_chain); /* Don't free filename any more */
301 core_file = filename;
302 ontop = !push_target (&kcore_ops);
304 kernel_start = bfd_get_start_address (exec_bfd); /* XXX */
306 /* print out the panic string if there is one */
307 if (kvread (ksym_lookup ("panicstr"), &addr) == 0
309 && target_read_memory (addr, buf, sizeof (buf)) == 0)
311 for (cp = buf; cp < &buf[sizeof (buf)] && *cp; cp++)
312 if (!isascii (*cp) || (!isprint (*cp) && !isspace (*cp)))
316 printf ("panicstr: %s\n", buf);
319 /* Print all the panic messages if possible. */
320 if (symfile_objfile != NULL)
322 printf ("panic messages:\n---\n");
323 snprintf (buf, sizeof buf,
324 "/sbin/dmesg -N %s -M %s | \
325 /usr/bin/awk '/^(panic:|Fatal trap) / { printing = 1 } \
326 { if (printing) print $0 }'",
327 symfile_objfile->name, filename);
335 warning ("you won't be able to access this core file until you terminate\n\
336 your %s; do ``info files''", target_longname);
340 /* we may need this later */
341 cur_proc = (struct proc *)curProc ();
342 /* Now, set up the frame cache, and print the top of stack */
343 flush_cached_frames ();
344 set_current_frame (create_new_frame (read_fp (), read_pc ()));
345 select_frame (get_current_frame (), 0);
346 print_stack_frame (selected_frame, selected_frame_level, 1);
350 kcore_detach (args, from_tty)
355 error ("Too many arguments");
356 unpush_target (&kcore_ops);
357 reinit_frame_cache ();
359 printf_filtered ("No kernel core file now.\n");
362 /* Get the registers out of a core file. This is the machine-
363 independent part. Fetch_core_registers is the machine-dependent
364 part, typically implemented in the xm-file for each architecture. */
366 /* We just get all the registers, so we don't use regno. */
369 get_kcore_registers (regno)
374 /* find the pcb for the current process */
375 if (cur_proc == NULL || kvread (&cur_proc->p_addr, &uaddr))
376 error ("cannot read u area ptr for proc at %#x", cur_proc);
377 if (read_pcb (core_kd, (CORE_ADDR)&uaddr->u_pcb) < 0)
378 error ("cannot read pcb at %#x", &uaddr->u_pcb);
383 struct target_ops *t;
385 printf ("\t`%s'\n", core_file);
391 static CORE_ADDR maxuseraddr;
392 struct minimal_symbol *sym;
394 if (maxuseraddr == 0)
396 sym = lookup_minimal_symbol ("PTmap", NULL, NULL);
398 maxuseraddr = VM_MAXUSER_ADDRESS;
400 maxuseraddr = SYMBOL_VALUE_ADDRESS (sym);
407 kcore_xfer_kmem (memaddr, myaddr, len, write, target)
412 struct target_ops *target;
417 if (memaddr >= ksym_maxuseraddr())
421 nu = xfer_umem (memaddr, myaddr, len, write);
427 if (memaddr != ksym_maxuseraddr())
433 ns = (write ? kvm_write : kvm_read) (core_kd, memaddr, myaddr, len);
441 xfer_umem (memaddr, myaddr, len, write)
445 int write; /* ignored */
450 if (cur_proc == NULL || kvread (cur_proc, &proc))
451 error ("cannot read proc at %#x", cur_proc);
452 n = kvm_uread (core_kd, &proc, memaddr, myaddr, len) ;
462 static CORE_ADDR kernbase;
463 struct minimal_symbol *sym;
467 sym = lookup_minimal_symbol ("kernbase", NULL, NULL);
471 kernbase = SYMBOL_VALUE_ADDRESS (sym);
477 #define KERNOFF (ksym_kernbase())
478 #define INKERNEL(x) ((x) >= KERNOFF)
480 static CORE_ADDR sbr;
481 static CORE_ADDR curpcb;
482 static int found_pcb;
485 static struct pcb pcb;
488 set_proc_cmd (arg, from_tty)
493 struct kinfo_proc *kp;
497 error_no_arg ("proc address for new current process");
498 if (!kernel_debugging)
499 error ("not debugging kernel");
501 paddr = (CORE_ADDR)parse_and_eval_address (arg);
502 /* assume it's a proc pointer if it's in the kernel */
503 if (paddr >= kernel_start) {
504 if (set_proc_context(paddr))
505 error("invalid proc address");
507 kp = kvm_getprocs(core_kd, KERN_PROC_PID, paddr, &cnt);
509 error("invalid pid");
510 if (set_proc_context((CORE_ADDR)kp->kp_eproc.e_paddr))
511 error("invalid proc address");
516 set_cpu_cmd (arg, from_tty)
521 struct kinfo_proc *kp;
525 error_no_arg ("cpu number");
526 if (!kernel_debugging)
527 error ("not debugging kernel");
529 error ("not debugging SMP kernel");
531 cpu = (int)parse_and_eval_address (arg);
532 if (cpu < 0 || cpu > ncpus)
533 error ("cpu number out of range");
537 curpcb = kvtophys(cfd, ksym_lookup ("gd_curpcb") + prv_start);
538 physrd (cfd, curpcb, (char*)&curpcb, sizeof curpcb);
541 paddr = ksym_lookup ("dumppcb") - KERNOFF;
543 paddr = kvtophys (cfd, curpcb);
544 read_pcb (cfd, paddr);
545 printf ("initial pcb at %lx\n", (unsigned long)paddr);
547 if ((cur_proc = curProc()))
548 target_fetch_registers (-1);
550 /* Now, set up the frame cache, and print the top of stack */
551 flush_cached_frames ();
552 set_current_frame (create_new_frame (read_fp (), read_pc ()));
553 select_frame (get_current_frame (), 0);
554 print_stack_frame (selected_frame, selected_frame_level, 1);
557 /* substitutes for the stuff in libkvm which doesn't work */
558 /* most of this was taken from the old kgdb */
560 /* we don't need all this stuff, but the call should look the same */
563 kvm_open (efile, cfile, sfile, perm, errout)
566 char *sfile; /* makes this kvm_open more compatible to the one in libkvm */
568 char *errout; /* makes this kvm_open more compatible to the one in libkvm */
574 if ((cfd = open (cfile, perm, 0)) < 0)
578 if ((stb.st_mode & S_IFMT) == S_IFCHR
579 && stb.st_rdev == makedev (2, 0))
582 kfd = open (_PATH_KMEM, perm, 0);
585 if (lookup_minimal_symbol("mp_ncpus", NULL, NULL)) {
586 physrd(cfd, ksym_lookup("mp_ncpus") - KERNOFF,
587 (char*)&ncpus, sizeof(ncpus));
588 prv_space = ksym_lookup("SMP_prvspace");
589 prv_space_size = (int)ksym_lookup("gd_idlestack_top");
590 printf ("SMP %d cpus\n", ncpus);
598 physrd (cfd, ksym_lookup ("IdlePTD") - KERNOFF, (char*)&sbr, sizeof sbr);
599 printf ("IdlePTD at phsyical address 0x%08lx\n", (unsigned long)sbr);
600 curpcb = kvtophys(cfd, ksym_lookup ("gd_curpcb") + prv_start);
601 physrd (cfd, curpcb, (char*)&curpcb, sizeof curpcb);
603 found_pcb = 1; /* for vtophys */
605 paddr = ksym_lookup ("dumppcb") - KERNOFF;
607 paddr = kvtophys (cfd, curpcb);
608 read_pcb (cfd, paddr);
609 printf ("initial pcb at physical address 0x%08lx\n", (unsigned long)paddr);
622 kvm_write (core_kd, memaddr, myaddr, len)
634 * Just like kvm_read, only we write.
637 if (lseek (kfd, (off_t)memaddr, 0) < 0
640 error ("kvm_write:invalid address (%x)", memaddr);
643 cc = write (kfd, myaddr, len);
646 error ("kvm_write:write failed");
650 error ("kvm_write:short write");
658 printf ("kvm_write not implemented for dead kernels\n");
665 kvm_read (core_kd, memaddr, myaddr, len)
670 return (kernel_core_file_hook (core_kd, memaddr, myaddr, len));
674 kvm_uread (core_kd, p, memaddr, myaddr, len)
676 register struct proc *p;
682 char procfile[MAXPATHLEN];
688 sprintf (procfile, "/proc/%d/mem", p->p_pid);
689 fd = open (procfile, O_RDONLY, 0);
692 error ("cannot open %s", procfile);
701 if (lseek (fd, (off_t)memaddr, 0) == -1 && errno != 0)
703 error ("invalid address (%x) in %s", memaddr, procfile);
706 amount = read (fd, cp, len);
709 error ("error reading %s", procfile);
714 error ("EOF reading %s", procfile);
723 return ((ssize_t) (cp - myaddr));
726 return (kernel_core_file_hook (core_kd, memaddr, myaddr, len));
729 static struct kinfo_proc kp;
732 * try to do what kvm_proclist in libkvm would do
735 kvm_proclist (cfd, pid, p, cnt)
741 for (; p != NULL; p = lp.p_list.le_next) {
742 if (!kvm_read(cfd, (CORE_ADDR)p, (char *)&lp, sizeof (lp)))
746 kp.kp_eproc.e_paddr = p;
755 * try to do what kvm_deadprocs in libkvm would do
757 static struct kinfo_proc *
758 kvm_deadprocs (cfd, pid, cnt)
761 CORE_ADDR allproc, zombproc;
764 allproc = ksym_lookup("allproc");
765 if (kvm_read(cfd, allproc, (char *)&p, sizeof (p)) == 0)
767 kvm_proclist (cfd, pid, p, cnt);
769 zombproc = ksym_lookup("zombproc");
770 if (kvm_read(cfd, zombproc, (char *)&p, sizeof (p)) == 0)
772 kvm_proclist (cfd, pid, p, cnt);
778 * try to do what kvm_getprocs in libkvm would do
780 static struct kinfo_proc *
781 kvm_getprocs (cfd, op, proc, cnt)
788 /* assume it's a pid */
789 if (devmem) { /* "live" kernel, use sysctl */
792 mib[2] = KERN_PROC_PID;
795 if (sysctl (mib, 4, &kp, &size, NULL, 0) < 0) {
806 return (kvm_deadprocs (cfd, (int)proc, cnt));
810 physrd (cfd, addr, dat, len)
816 if (lseek (cfd, (off_t)addr, L_SET) == -1)
818 return (read (cfd, dat, len));
828 static CORE_ADDR PTD = -1;
829 CORE_ADDR current_ptd;
832 * We may no longer have a linear system page table...
834 * Here's the scoop. IdlePTD contains the physical address
835 * of a page table directory that always maps the kernel.
836 * IdlePTD is in memory that is mapped 1-to-1, so we can
837 * find it easily given its 'virtual' address from ksym_lookup().
838 * For hysterical reasons, the value of IdlePTD is stored in sbr.
840 * To look up a kernel address, we first convert it to a 1st-level
841 * address and look it up in IdlePTD. This gives us the physical
842 * address of a page table page; we extract the 2nd-level part of
843 * VA and read the 2nd-level pte. Finally, we add the offset part
844 * of the VA into the physical address from the pte and return it.
846 * User addresses are a little more complicated. If we don't have
847 * a current PCB from read_pcb(), we use PTD, which is the (fixed)
848 * virtual address of the current ptd. Since it's NOT in 1-to-1
849 * kernel space, we must look it up using IdlePTD. If we do have
850 * a pcb, we get the ptd from pcb_ptd.
855 else if (found_pcb == 0)
858 PTD = kvtophys (fd, ksym_lookup ("PTD"));
862 current_ptd = pcb.pcb_cr3;
865 * Read the first-level page table (ptd).
867 v = current_ptd + ( (unsigned)addr >> PDRSHIFT) * sizeof pte;
868 if (physrd (fd, v, (char *)&pte, sizeof pte) < 0 || (pte&PG_V) == 0)
874 * No second-level page table; ptd describes one 4MB page.
875 * (We assume that the kernel wouldn't set PG_PS without enabling
876 * it cr0, and that the kernel doesn't support 36-bit physical
879 #define PAGE4M_MASK (NBPDR - 1)
880 #define PG_FRAME4M (~PAGE4M_MASK)
881 addr = (pte & PG_FRAME4M) + (addr & PAGE4M_MASK);
886 * Read the second-level page table.
888 v = (pte&PG_FRAME) + ((addr >> PAGE_SHIFT)&(NPTEPG-1)) * sizeof pte;
889 if (physrd (fd, v, (char *) &pte, sizeof (pte)) < 0 || (pte&PG_V) == 0)
892 addr = (pte & PG_FRAME) + (addr & PAGE_MASK);
895 printf ("vtophys (%x) -> %x\n", oldaddr, addr);
907 CORE_ADDR nuaddr = uaddr;
909 /* need this for the `proc' command to work */
911 nuaddr = kvtophys(fd, uaddr);
913 if (physrd (fd, nuaddr, (char *)&pcb, sizeof pcb) < 0)
915 error ("cannot read pcb at %x\n", uaddr);
920 * get the register values out of the sys pcb and
921 * store them where `read_register' will find them.
924 * XXX many registers aren't available.
925 * XXX for the non-core case, the registers are stale - they are for
926 * the last context switch to the debugger.
927 * XXX gcc's register numbers aren't all #defined in tm-i386.h.
930 for (i = 0; i < 3; ++i) /* eax,ecx,edx */
931 supply_register (i, (char *)&noreg);
932 supply_register (3, (char *)&pcb.pcb_ebx);
933 supply_register (SP_REGNUM, (char *)&pcb.pcb_esp);
934 supply_register (FP_REGNUM, (char *)&pcb.pcb_ebp);
935 supply_register (6, (char *)&pcb.pcb_esi);
936 supply_register (7, (char *)&pcb.pcb_edi);
937 supply_register (PC_REGNUM, (char *)&pcb.pcb_eip);
938 for (i = 9; i < 14; ++i) /* eflags, cs, ss, ds, es, fs */
939 supply_register (i, (char *)&noreg);
940 supply_register (15, (char *)&pcb.pcb_gs);
942 /* XXX 80387 registers? */
946 * read len bytes from kernel virtual address 'addr' into local
947 * buffer 'buf'. Return numbert of bytes if read ok, 0 otherwise. On read
948 * errors, portion of buffer not read is zeroed.
952 kernel_core_file_hook (fd, addr, buf, len)
967 paddr = kvtophys (fd, addr);
970 memset (buf, '\000', len);
973 /* we can't read across a page boundary */
974 i = min (len, PAGE_SIZE - (addr & PAGE_MASK));
975 if ( (cc = physrd (fd, paddr, cp, i)) <= 0)
977 memset (cp, '\000', len);
987 static struct target_ops kcore_ops;
990 _initialize_kcorelow()
992 kcore_ops.to_shortname = "kcore";
993 kcore_ops.to_longname = "Kernel core dump file";
995 "Use a core file as a target. Specify the filename of the core file.";
996 kcore_ops.to_open = kcore_open;
997 kcore_ops.to_close = kcore_close;
998 kcore_ops.to_attach = find_default_attach;
999 kcore_ops.to_detach = kcore_detach;
1000 kcore_ops.to_fetch_registers = get_kcore_registers;
1001 kcore_ops.to_xfer_memory = kcore_xfer_kmem;
1002 kcore_ops.to_files_info = kcore_files_info;
1003 kcore_ops.to_create_inferior = find_default_create_inferior;
1004 kcore_ops.to_stratum = kcore_stratum;
1005 kcore_ops.to_has_memory = 1;
1006 kcore_ops.to_has_stack = 1;
1007 kcore_ops.to_has_registers = 1;
1008 kcore_ops.to_magic = OPS_MAGIC;
1010 add_target (&kcore_ops);
1011 add_com ("proc", class_obscure, set_proc_cmd, "Set current process context");
1012 add_com ("cpu", class_obscure, set_cpu_cmd, "Set current cpu");