cf424aef0a
- Use signal frame sniffers that look for the signal trampoline instruction sequence to detect most signal frames. - FreeBSD kernels between 9.2 and 10.1 inclusive do not include the signal trampoline code in process core dumps. To detect signal frames for core dumps under these kernels, use the kern.proc.sigtramp.<pid> sysctl to fetch the location of the signal trampoline in the gdb process and assume that PC values within this location are signal frames. This depends on that location being identical for all binaries. gdb/ChangeLog: 2015-02-25 John Baldwin <jhb@FreeBSD.org> * amd64fbsd-nat.c: Include sys/user.h. (_initialize_amd64fbsd_nat): Use the KERN_PROC_SIGTRAMP sysctl instead of KERN_PS_STRINGS to locate the signal trampoline. * i386fbsd-nat.c: Include sys/user.h. (_initialize_i386fbsd_nat): Use the KERN_PROC_SIGTRAMP sysctl instead of KERN_PS_STRINGS to locate the signal trampoline. * amd64fbsd-tdep.c (amd64fbsd_sigtramp_code): New. (amd64fbsd_sigtramp_p): New. (amd64fbsd_sigtramp_start_addr, amd64fbsd_sigtramp_end_addr): No longer set default values. (amd64fbsd_init_abi): Set "sigtramp_p" to "amd64fbsd_sigtramp_p". * i386fbsd-tdep.c (i386fbsd_sigtramp_start) (i386fbsd_sigtramp_middle, i386fbsd_sigtramp_end) (i386fbsd_freebsd4_sigtramp_start) (i386fbsd_freebsd4_sigtramp_middle) (i386fbsd_freebsd4_sigtramp_end, i386fbsd_osigtramp_start) (i386fbsd_osigtramp_middle, i386fbsd_osigtramp_end): New. (i386fbsd_sigtramp_p): New. (i386fbsd_sigtramp_start_addr, i386fbsd_sigtramp_end_addr): No longer set default values. (i386fbsd_init_abi): Set "sigtramp_p" to "i386fbsd_sigtramp_p".
275 lines
8.4 KiB
C
275 lines
8.4 KiB
C
/* Native-dependent code for FreeBSD/amd64.
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Copyright (C) 2003-2015 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "inferior.h"
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#include "regcache.h"
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#include "target.h"
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#include <signal.h>
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#include <sys/types.h>
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#include <sys/ptrace.h>
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#include <sys/sysctl.h>
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#include <sys/user.h>
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#include <machine/reg.h>
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#include "fbsd-nat.h"
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#include "amd64-tdep.h"
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#include "amd64-nat.h"
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#include "amd64bsd-nat.h"
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#include "x86-nat.h"
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/* Offset in `struct reg' where MEMBER is stored. */
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#define REG_OFFSET(member) offsetof (struct reg, member)
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/* At amd64fbsd64_r_reg_offset[REGNUM] you'll find the offset in
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`struct reg' location where the GDB register REGNUM is stored.
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Unsupported registers are marked with `-1'. */
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static int amd64fbsd64_r_reg_offset[] =
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{
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REG_OFFSET (r_rax),
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REG_OFFSET (r_rbx),
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REG_OFFSET (r_rcx),
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REG_OFFSET (r_rdx),
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REG_OFFSET (r_rsi),
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REG_OFFSET (r_rdi),
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REG_OFFSET (r_rbp),
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REG_OFFSET (r_rsp),
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REG_OFFSET (r_r8),
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REG_OFFSET (r_r9),
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REG_OFFSET (r_r10),
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REG_OFFSET (r_r11),
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REG_OFFSET (r_r12),
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REG_OFFSET (r_r13),
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REG_OFFSET (r_r14),
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REG_OFFSET (r_r15),
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REG_OFFSET (r_rip),
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REG_OFFSET (r_rflags),
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REG_OFFSET (r_cs),
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REG_OFFSET (r_ss),
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-1,
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-1,
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-1,
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-1
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};
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/* Mapping between the general-purpose registers in FreeBSD/amd64
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`struct reg' format and GDB's register cache layout for
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FreeBSD/i386.
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Note that most FreeBSD/amd64 registers are 64-bit, while the
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FreeBSD/i386 registers are all 32-bit, but since we're
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little-endian we get away with that. */
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/* From <machine/reg.h>. */
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static int amd64fbsd32_r_reg_offset[I386_NUM_GREGS] =
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{
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14 * 8, 13 * 8, /* %eax, %ecx */
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12 * 8, 11 * 8, /* %edx, %ebx */
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20 * 8, 10 * 8, /* %esp, %ebp */
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9 * 8, 8 * 8, /* %esi, %edi */
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17 * 8, 19 * 8, /* %eip, %eflags */
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18 * 8, 21 * 8, /* %cs, %ss */
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-1, -1, -1, -1 /* %ds, %es, %fs, %gs */
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};
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/* Support for debugging kernel virtual memory images. */
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#include <machine/pcb.h>
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#include <osreldate.h>
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#include "bsd-kvm.h"
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static int
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amd64fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
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{
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/* The following is true for FreeBSD 5.2:
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The pcb contains %rip, %rbx, %rsp, %rbp, %r12, %r13, %r14, %r15,
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%ds, %es, %fs and %gs. This accounts for all callee-saved
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registers specified by the psABI and then some. Here %esp
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contains the stack pointer at the point just after the call to
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cpu_switch(). From this information we reconstruct the register
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state as it would like when we just returned from cpu_switch(). */
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/* The stack pointer shouldn't be zero. */
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if (pcb->pcb_rsp == 0)
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return 0;
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pcb->pcb_rsp += 8;
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regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &pcb->pcb_rip);
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regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &pcb->pcb_rbx);
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regcache_raw_supply (regcache, AMD64_RSP_REGNUM, &pcb->pcb_rsp);
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regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &pcb->pcb_rbp);
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regcache_raw_supply (regcache, 12, &pcb->pcb_r12);
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regcache_raw_supply (regcache, 13, &pcb->pcb_r13);
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regcache_raw_supply (regcache, 14, &pcb->pcb_r14);
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regcache_raw_supply (regcache, 15, &pcb->pcb_r15);
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#if (__FreeBSD_version < 800075) && (__FreeBSD_kernel_version < 800075)
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/* struct pcb provides the pcb_ds/pcb_es/pcb_fs/pcb_gs fields only
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up until __FreeBSD_version 800074: The removal of these fields
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occurred on 2009-04-01 while the __FreeBSD_version number was
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bumped to 800075 on 2009-04-06. So 800075 is the closest version
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number where we should not try to access these fields. */
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regcache_raw_supply (regcache, AMD64_DS_REGNUM, &pcb->pcb_ds);
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regcache_raw_supply (regcache, AMD64_ES_REGNUM, &pcb->pcb_es);
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regcache_raw_supply (regcache, AMD64_FS_REGNUM, &pcb->pcb_fs);
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regcache_raw_supply (regcache, AMD64_GS_REGNUM, &pcb->pcb_gs);
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#endif
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return 1;
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}
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static void (*super_mourn_inferior) (struct target_ops *ops);
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static void
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amd64fbsd_mourn_inferior (struct target_ops *ops)
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{
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#ifdef HAVE_PT_GETDBREGS
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x86_cleanup_dregs ();
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#endif
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super_mourn_inferior (ops);
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}
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/* Provide a prototype to silence -Wmissing-prototypes. */
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void _initialize_amd64fbsd_nat (void);
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void
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_initialize_amd64fbsd_nat (void)
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{
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struct target_ops *t;
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int offset;
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amd64_native_gregset32_reg_offset = amd64fbsd32_r_reg_offset;
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amd64_native_gregset64_reg_offset = amd64fbsd64_r_reg_offset;
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/* Add some extra features to the common *BSD/i386 target. */
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t = amd64bsd_target ();
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#ifdef HAVE_PT_GETDBREGS
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x86_use_watchpoints (t);
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x86_dr_low.set_control = amd64bsd_dr_set_control;
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x86_dr_low.set_addr = amd64bsd_dr_set_addr;
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x86_dr_low.get_addr = amd64bsd_dr_get_addr;
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x86_dr_low.get_status = amd64bsd_dr_get_status;
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x86_dr_low.get_control = amd64bsd_dr_get_control;
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x86_set_debug_register_length (8);
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#endif /* HAVE_PT_GETDBREGS */
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super_mourn_inferior = t->to_mourn_inferior;
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t->to_mourn_inferior = amd64fbsd_mourn_inferior;
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t->to_pid_to_exec_file = fbsd_pid_to_exec_file;
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t->to_find_memory_regions = fbsd_find_memory_regions;
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add_target (t);
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/* Support debugging kernel virtual memory images. */
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bsd_kvm_add_target (amd64fbsd_supply_pcb);
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/* To support the recognition of signal handlers, i386bsd-tdep.c
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hardcodes some constants. Inclusion of this file means that we
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are compiling a native debugger, which means that we can use the
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system header files and sysctl(3) to get at the relevant
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information. */
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#define SC_REG_OFFSET amd64fbsd_sc_reg_offset
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/* We only check the program counter, stack pointer and frame
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pointer since these members of `struct sigcontext' are essential
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for providing backtraces. */
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#define SC_RIP_OFFSET SC_REG_OFFSET[AMD64_RIP_REGNUM]
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#define SC_RSP_OFFSET SC_REG_OFFSET[AMD64_RSP_REGNUM]
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#define SC_RBP_OFFSET SC_REG_OFFSET[AMD64_RBP_REGNUM]
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/* Override the default value for the offset of the program counter
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in the sigcontext structure. */
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offset = offsetof (struct sigcontext, sc_rip);
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if (SC_RIP_OFFSET != offset)
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{
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warning (_("\
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offsetof (struct sigcontext, sc_rip) yields %d instead of %d.\n\
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Please report this to <bug-gdb@gnu.org>."),
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offset, SC_RIP_OFFSET);
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}
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SC_RIP_OFFSET = offset;
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/* Likewise for the stack pointer. */
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offset = offsetof (struct sigcontext, sc_rsp);
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if (SC_RSP_OFFSET != offset)
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{
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warning (_("\
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offsetof (struct sigcontext, sc_rsp) yields %d instead of %d.\n\
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Please report this to <bug-gdb@gnu.org>."),
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offset, SC_RSP_OFFSET);
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}
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SC_RSP_OFFSET = offset;
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/* And the frame pointer. */
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offset = offsetof (struct sigcontext, sc_rbp);
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if (SC_RBP_OFFSET != offset)
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{
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warning (_("\
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offsetof (struct sigcontext, sc_rbp) yields %d instead of %d.\n\
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Please report this to <bug-gdb@gnu.org>."),
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offset, SC_RBP_OFFSET);
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}
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SC_RBP_OFFSET = offset;
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#ifdef KERN_PROC_SIGTRAMP
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/* Normally signal frames are detected via amd64fbsd_sigtramp_p.
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However, FreeBSD 9.2 through 10.1 do not include the page holding
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the signal code in core dumps. These releases do provide a
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kern.proc.sigtramp.<pid> sysctl that returns the location of the
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signal trampoline for a running process. We fetch the location
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of the current (gdb) process and use this to identify signal
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frames in core dumps from these releases. Note that this only
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works for core dumps of 64-bit (FreeBSD/amd64) processes and does
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not handle core dumps of 32-bit (FreeBSD/i386) processes. */
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{
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int mib[4];
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struct kinfo_sigtramp kst;
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size_t len;
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mib[0] = CTL_KERN;
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mib[1] = KERN_PROC;
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mib[2] = KERN_PROC_SIGTRAMP;
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mib[3] = getpid ();
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len = sizeof (kst);
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if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0)
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{
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amd64fbsd_sigtramp_start_addr = (uintptr_t) kst.ksigtramp_start;
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amd64fbsd_sigtramp_end_addr = (uintptr_t) kst.ksigtramp_end;
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}
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}
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#endif
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}
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