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Diffstat (limited to 'gdb/amd64-fbsd-nat.c')
-rw-r--r-- | gdb/amd64-fbsd-nat.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/gdb/amd64-fbsd-nat.c b/gdb/amd64-fbsd-nat.c new file mode 100644 index 0000000..fce2699 --- /dev/null +++ b/gdb/amd64-fbsd-nat.c @@ -0,0 +1,291 @@ +/* Native-dependent code for FreeBSD/amd64. + + Copyright (C) 2003-2016 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 3 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, see <http://www.gnu.org/licenses/>. */ + +#include "defs.h" +#include "inferior.h" +#include "regcache.h" +#include "target.h" + +#include <signal.h> +#include <sys/types.h> +#include <sys/ptrace.h> +#include <sys/sysctl.h> +#include <sys/user.h> +#include <machine/reg.h> + +#include "fbsd-nat.h" +#include "amd64-tdep.h" +#include "amd64-nat.h" +#include "x86-bsd-nat.h" +#include "x86-nat.h" + + +/* Offset in `struct reg' where MEMBER is stored. */ +#define REG_OFFSET(member) offsetof (struct reg, member) + +/* At amd64fbsd64_r_reg_offset[REGNUM] you'll find the offset in + `struct reg' location where the GDB register REGNUM is stored. + Unsupported registers are marked with `-1'. */ +static int amd64fbsd64_r_reg_offset[] = +{ + REG_OFFSET (r_rax), + REG_OFFSET (r_rbx), + REG_OFFSET (r_rcx), + REG_OFFSET (r_rdx), + REG_OFFSET (r_rsi), + REG_OFFSET (r_rdi), + REG_OFFSET (r_rbp), + REG_OFFSET (r_rsp), + REG_OFFSET (r_r8), + REG_OFFSET (r_r9), + REG_OFFSET (r_r10), + REG_OFFSET (r_r11), + REG_OFFSET (r_r12), + REG_OFFSET (r_r13), + REG_OFFSET (r_r14), + REG_OFFSET (r_r15), + REG_OFFSET (r_rip), + REG_OFFSET (r_rflags), + REG_OFFSET (r_cs), + REG_OFFSET (r_ss), + -1, + -1, + -1, + -1 +}; + + +/* Mapping between the general-purpose registers in FreeBSD/amd64 + `struct reg' format and GDB's register cache layout for + FreeBSD/i386. + + Note that most FreeBSD/amd64 registers are 64-bit, while the + FreeBSD/i386 registers are all 32-bit, but since we're + little-endian we get away with that. */ + +/* From <machine/reg.h>. */ +static int amd64fbsd32_r_reg_offset[I386_NUM_GREGS] = +{ + 14 * 8, 13 * 8, /* %eax, %ecx */ + 12 * 8, 11 * 8, /* %edx, %ebx */ + 20 * 8, 10 * 8, /* %esp, %ebp */ + 9 * 8, 8 * 8, /* %esi, %edi */ + 17 * 8, 19 * 8, /* %eip, %eflags */ + 18 * 8, 21 * 8, /* %cs, %ss */ + -1, -1, -1, -1 /* %ds, %es, %fs, %gs */ +}; + + +/* Support for debugging kernel virtual memory images. */ + +#include <machine/pcb.h> +#include <osreldate.h> + +#include "bsd-kvm.h" + +static int +amd64fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb) +{ + /* The following is true for FreeBSD 5.2: + + The pcb contains %rip, %rbx, %rsp, %rbp, %r12, %r13, %r14, %r15, + %ds, %es, %fs and %gs. This accounts for all callee-saved + registers specified by the psABI and then some. Here %esp + contains the stack pointer at the point just after the call to + cpu_switch(). From this information we reconstruct the register + state as it would like when we just returned from cpu_switch(). */ + + /* The stack pointer shouldn't be zero. */ + if (pcb->pcb_rsp == 0) + return 0; + + pcb->pcb_rsp += 8; + regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &pcb->pcb_rip); + regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &pcb->pcb_rbx); + regcache_raw_supply (regcache, AMD64_RSP_REGNUM, &pcb->pcb_rsp); + regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &pcb->pcb_rbp); + regcache_raw_supply (regcache, 12, &pcb->pcb_r12); + regcache_raw_supply (regcache, 13, &pcb->pcb_r13); + regcache_raw_supply (regcache, 14, &pcb->pcb_r14); + regcache_raw_supply (regcache, 15, &pcb->pcb_r15); +#if (__FreeBSD_version < 800075) && (__FreeBSD_kernel_version < 800075) + /* struct pcb provides the pcb_ds/pcb_es/pcb_fs/pcb_gs fields only + up until __FreeBSD_version 800074: The removal of these fields + occurred on 2009-04-01 while the __FreeBSD_version number was + bumped to 800075 on 2009-04-06. So 800075 is the closest version + number where we should not try to access these fields. */ + regcache_raw_supply (regcache, AMD64_DS_REGNUM, &pcb->pcb_ds); + regcache_raw_supply (regcache, AMD64_ES_REGNUM, &pcb->pcb_es); + regcache_raw_supply (regcache, AMD64_FS_REGNUM, &pcb->pcb_fs); + regcache_raw_supply (regcache, AMD64_GS_REGNUM, &pcb->pcb_gs); +#endif + + return 1; +} + + +/* Implement the to_read_description method. */ + +static const struct target_desc * +amd64fbsd_read_description (struct target_ops *ops) +{ +#ifdef PT_GETXSTATE_INFO + static int xsave_probed; + static uint64_t xcr0; +#endif + struct reg regs; + int is64; + + if (ptrace (PT_GETREGS, ptid_get_pid (inferior_ptid), + (PTRACE_TYPE_ARG3) ®s, 0) == -1) + perror_with_name (_("Couldn't get registers")); + is64 = (regs.r_cs == GSEL (GUCODE_SEL, SEL_UPL)); +#ifdef PT_GETXSTATE_INFO + if (!xsave_probed) + { + struct ptrace_xstate_info info; + + if (ptrace (PT_GETXSTATE_INFO, ptid_get_pid (inferior_ptid), + (PTRACE_TYPE_ARG3) &info, sizeof (info)) == 0) + { + x86bsd_xsave_len = info.xsave_len; + xcr0 = info.xsave_mask; + } + xsave_probed = 1; + } + + if (x86bsd_xsave_len != 0) + { + if (is64) + return amd64_target_description (xcr0); + else + return i386_target_description (xcr0); + } +#endif + if (is64) + return tdesc_amd64; + else + return tdesc_i386; +} + +/* Provide a prototype to silence -Wmissing-prototypes. */ +void _initialize_amd64fbsd_nat (void); + +void +_initialize_amd64fbsd_nat (void) +{ + struct target_ops *t; + int offset; + + amd64_native_gregset32_reg_offset = amd64fbsd32_r_reg_offset; + amd64_native_gregset64_reg_offset = amd64fbsd64_r_reg_offset; + + /* Add some extra features to the common *BSD/i386 target. */ + t = amd64bsd_target (); + t->to_read_description = amd64fbsd_read_description; + + fbsd_nat_add_target (t); + + /* Support debugging kernel virtual memory images. */ + bsd_kvm_add_target (amd64fbsd_supply_pcb); + + /* To support the recognition of signal handlers, i386-bsd-tdep.c + hardcodes some constants. Inclusion of this file means that we + are compiling a native debugger, which means that we can use the + system header files and sysctl(3) to get at the relevant + information. */ + +#define SC_REG_OFFSET amd64fbsd_sc_reg_offset + + /* We only check the program counter, stack pointer and frame + pointer since these members of `struct sigcontext' are essential + for providing backtraces. */ + +#define SC_RIP_OFFSET SC_REG_OFFSET[AMD64_RIP_REGNUM] +#define SC_RSP_OFFSET SC_REG_OFFSET[AMD64_RSP_REGNUM] +#define SC_RBP_OFFSET SC_REG_OFFSET[AMD64_RBP_REGNUM] + + /* Override the default value for the offset of the program counter + in the sigcontext structure. */ + offset = offsetof (struct sigcontext, sc_rip); + + if (SC_RIP_OFFSET != offset) + { + warning (_("\ +offsetof (struct sigcontext, sc_rip) yields %d instead of %d.\n\ +Please report this to <bug-gdb@gnu.org>."), + offset, SC_RIP_OFFSET); + } + + SC_RIP_OFFSET = offset; + + /* Likewise for the stack pointer. */ + offset = offsetof (struct sigcontext, sc_rsp); + + if (SC_RSP_OFFSET != offset) + { + warning (_("\ +offsetof (struct sigcontext, sc_rsp) yields %d instead of %d.\n\ +Please report this to <bug-gdb@gnu.org>."), + offset, SC_RSP_OFFSET); + } + + SC_RSP_OFFSET = offset; + + /* And the frame pointer. */ + offset = offsetof (struct sigcontext, sc_rbp); + + if (SC_RBP_OFFSET != offset) + { + warning (_("\ +offsetof (struct sigcontext, sc_rbp) yields %d instead of %d.\n\ +Please report this to <bug-gdb@gnu.org>."), + offset, SC_RBP_OFFSET); + } + + SC_RBP_OFFSET = offset; + +#ifdef KERN_PROC_SIGTRAMP + /* Normally signal frames are detected via amd64fbsd_sigtramp_p. + However, FreeBSD 9.2 through 10.1 do not include the page holding + the signal code in core dumps. These releases do provide a + kern.proc.sigtramp.<pid> sysctl that returns the location of the + signal trampoline for a running process. We fetch the location + of the current (gdb) process and use this to identify signal + frames in core dumps from these releases. Note that this only + works for core dumps of 64-bit (FreeBSD/amd64) processes and does + not handle core dumps of 32-bit (FreeBSD/i386) processes. */ + { + int mib[4]; + struct kinfo_sigtramp kst; + size_t len; + + mib[0] = CTL_KERN; + mib[1] = KERN_PROC; + mib[2] = KERN_PROC_SIGTRAMP; + mib[3] = getpid (); + len = sizeof (kst); + if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0) + { + amd64fbsd_sigtramp_start_addr = (uintptr_t) kst.ksigtramp_start; + amd64fbsd_sigtramp_end_addr = (uintptr_t) kst.ksigtramp_end; + } + } +#endif +} |