/* BSD Kernel Data Access Library (libkvm) interface. Copyright 2004 Free Software Foundation, Inc. This file is part of GDB. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "defs.h" #include "frame.h" #include "regcache.h" #include "target.h" #include "gdb_assert.h" #include <fcntl.h> #include <kvm.h> #include <nlist.h> #include "readline/readline.h" #include <sys/param.h> #include <sys/user.h> #include "bsd-kvm.h" /* Kernel memory interface descriptor. */ kvm_t *core_kd; /* Address of process control block. */ struct pcb *bsd_kvm_paddr; /* Pointer to architecture-specific function that reconstructs the register state from PCB and supplies it to REGCACHE. */ int (*bsd_kvm_supply_pcb)(struct regcache *regcache, struct pcb *pcb); /* Target ops for libkvm interface. */ struct target_ops bsd_kvm_ops; static void bsd_kvm_open (char *filename, int from_tty) { char errbuf[_POSIX2_LINE_MAX]; char *execfile = NULL; kvm_t *temp_kd; target_preopen (from_tty); if (filename) { char *temp; filename = tilde_expand (filename); if (filename[0] != '/') { temp = concat (current_directory, "/", filename, NULL); xfree (filename); filename = temp; } } temp_kd = kvm_openfiles (execfile, filename, NULL, O_RDONLY, errbuf); if (temp_kd == NULL) error ("%s", errbuf); unpush_target (&bsd_kvm_ops); core_kd = temp_kd; push_target (&bsd_kvm_ops); target_fetch_registers (-1); flush_cached_frames (); select_frame (get_current_frame ()); print_stack_frame (get_selected_frame (), -1, 1); } static void bsd_kvm_close (int quitting) { if (core_kd) { if (kvm_close (core_kd) == -1) warning ("%s", kvm_geterr(core_kd)); core_kd = NULL; } } static int bsd_kvm_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write, struct mem_attrib *attrib, struct target_ops *ops) { if (write) return kvm_write (core_kd, memaddr, myaddr, len); else return kvm_read (core_kd, memaddr, myaddr, len); return -1; } /* Fetch process control block at address PADDR. */ static int bsd_kvm_fetch_pcb (struct pcb *paddr) { struct pcb pcb; if (kvm_read (core_kd, (unsigned long) paddr, &pcb, sizeof pcb) == -1) error ("%s", kvm_geterr (core_kd)); gdb_assert (bsd_kvm_supply_pcb); return bsd_kvm_supply_pcb (current_regcache, &pcb); } static void bsd_kvm_fetch_registers (int regnum) { struct nlist nl[2]; if (bsd_kvm_paddr) bsd_kvm_fetch_pcb (bsd_kvm_paddr); /* On dumping core, BSD kernels store the faulting context (PCB) in the variable "dumppcb". */ memset (nl, 0, sizeof nl); nl[0].n_name = "_dumppcb"; if (kvm_nlist (core_kd, nl) == -1) error ("%s", kvm_geterr (core_kd)); if (nl[0].n_value != 0) { /* Found dumppcb. If it contains a valid context, return immediately. */ if (bsd_kvm_fetch_pcb ((struct pcb *) nl[0].n_value)) return; } /* Traditional BSD kernels have a process proc0 that should always be present. The address of proc0's PCB is stored in the variable "proc0paddr". */ memset (nl, 0, sizeof nl); nl[0].n_name = "_proc0paddr"; if (kvm_nlist (core_kd, nl) == -1) error ("%s", kvm_geterr (core_kd)); if (nl[0].n_value != 0) { struct pcb *paddr; /* Found proc0paddr. */ if (kvm_read (core_kd, nl[0].n_value, &paddr, sizeof paddr) == -1) error ("%s", kvm_geterr (core_kd)); bsd_kvm_fetch_pcb (paddr); return; } #ifdef HAVE_STRUCT_THREAD_TD_PCB /* In FreeBSD kernels for 5.0-RELEASE and later, the PCB no longer lives in `struct proc' but in `struct thread'. The `struct thread' for the initial thread for proc0 can be found in the variable "thread0". */ memset (nl, 0, sizeof nl); nl[0].n_name = "_thread0"; if (kvm_nlist (core_kd, nl) == -1) error ("%s", kvm_geterr (core_kd)); if (nl[0].n_value != 0) { struct pcb *paddr; /* Found thread0. */ nl[1].n_value += offsetof (struct thread, td_pcb); if (kvm_read (core_kd, nl[1].n_value, &paddr, sizeof paddr) == -1) error ("%s", kvm_geterr (core_kd)); bsd_kvm_fetch_pcb (paddr); return; } #endif error ("Cannot find a valid PCB"); } /* Add the libkvm interface to the list of all possible targets and register CUPPLY_PCB as the architecture-specific process control block interpreter. */ void bsd_kvm_add_target (int (*supply_pcb)(struct regcache *, struct pcb *)) { gdb_assert (bsd_kvm_supply_pcb == NULL); bsd_kvm_supply_pcb = supply_pcb; bsd_kvm_ops.to_shortname = "kvm"; bsd_kvm_ops.to_longname = "Kernel memory interface"; bsd_kvm_ops.to_doc = "Use a kernel virtual memory image as a target.\n\ Optionally specify the filename of a core dump."; bsd_kvm_ops.to_open = bsd_kvm_open; bsd_kvm_ops.to_close = bsd_kvm_close; bsd_kvm_ops.to_fetch_registers = bsd_kvm_fetch_registers; bsd_kvm_ops.to_xfer_memory = bsd_kvm_xfer_memory; bsd_kvm_ops.to_stratum = process_stratum; bsd_kvm_ops.to_has_memory = 1; bsd_kvm_ops.to_has_stack = 1; bsd_kvm_ops.to_has_registers = 1; bsd_kvm_ops.to_magic = OPS_MAGIC; add_target (&bsd_kvm_ops); }