diff options
Diffstat (limited to 'gdb/i386-fbsd-tdep.c')
| -rw-r--r-- | gdb/i386-fbsd-tdep.c | 498 |
1 files changed, 498 insertions, 0 deletions
diff --git a/gdb/i386-fbsd-tdep.c b/gdb/i386-fbsd-tdep.c new file mode 100644 index 0000000..a08523a --- /dev/null +++ b/gdb/i386-fbsd-tdep.c @@ -0,0 +1,498 @@ +/* Target-dependent code for FreeBSD/i386. + + 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 "arch-utils.h" +#include "gdbcore.h" +#include "osabi.h" +#include "regcache.h" +#include "regset.h" +#include "i386-fbsd-tdep.h" +#include "x86-xstate.h" + +#include "i386-tdep.h" +#include "i387-tdep.h" +#include "bsd-uthread.h" +#include "fbsd-tdep.h" +#include "solib-svr4.h" + +/* Support for signal handlers. */ + +/* Return whether THIS_FRAME corresponds to a FreeBSD sigtramp + routine. */ + +/* FreeBSD/i386 supports three different signal trampolines, one for + versions before 4.0, a second for 4.x, and a third for 5.0 and + later. To complicate matters, FreeBSD/i386 binaries running under + an amd64 kernel use a different set of trampolines. These + trampolines differ from the i386 kernel trampolines in that they + omit a middle section that conditionally restores %gs. */ + +static const gdb_byte i386fbsd_sigtramp_start[] = +{ + 0x8d, 0x44, 0x24, 0x20, /* lea SIGF_UC(%esp),%eax */ + 0x50 /* pushl %eax */ +}; + +static const gdb_byte i386fbsd_sigtramp_middle[] = +{ + 0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00, + /* testl $PSL_VM,UC_EFLAGS(%eax) */ + 0x75, 0x03, /* jne +3 */ + 0x8e, 0x68, 0x14 /* mov UC_GS(%eax),%gs */ +}; + +static const gdb_byte i386fbsd_sigtramp_end[] = +{ + 0xb8, 0xa1, 0x01, 0x00, 0x00, /* movl $SYS_sigreturn,%eax */ + 0x50, /* pushl %eax */ + 0xcd, 0x80 /* int $0x80 */ +}; + +static const gdb_byte i386fbsd_freebsd4_sigtramp_start[] = +{ + 0x8d, 0x44, 0x24, 0x14, /* lea SIGF_UC4(%esp),%eax */ + 0x50 /* pushl %eax */ +}; + +static const gdb_byte i386fbsd_freebsd4_sigtramp_middle[] = +{ + 0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00, + /* testl $PSL_VM,UC4_EFLAGS(%eax) */ + 0x75, 0x03, /* jne +3 */ + 0x8e, 0x68, 0x14 /* mov UC4_GS(%eax),%gs */ +}; + +static const gdb_byte i386fbsd_freebsd4_sigtramp_end[] = +{ + 0xb8, 0x58, 0x01, 0x00, 0x00, /* movl $344,%eax */ + 0x50, /* pushl %eax */ + 0xcd, 0x80 /* int $0x80 */ +}; + +static const gdb_byte i386fbsd_osigtramp_start[] = +{ + 0x8d, 0x44, 0x24, 0x14, /* lea SIGF_SC(%esp),%eax */ + 0x50 /* pushl %eax */ +}; + +static const gdb_byte i386fbsd_osigtramp_middle[] = +{ + 0xf7, 0x40, 0x18, 0x00, 0x00, 0x02, 0x00, + /* testl $PSL_VM,SC_PS(%eax) */ + 0x75, 0x03, /* jne +3 */ + 0x8e, 0x68, 0x44 /* mov SC_GS(%eax),%gs */ +}; + +static const gdb_byte i386fbsd_osigtramp_end[] = +{ + 0xb8, 0x67, 0x00, 0x00, 0x00, /* movl $103,%eax */ + 0x50, /* pushl %eax */ + 0xcd, 0x80 /* int $0x80 */ +}; + +/* The three different trampolines are all the same size. */ +gdb_static_assert (sizeof i386fbsd_sigtramp_start + == sizeof i386fbsd_freebsd4_sigtramp_start); +gdb_static_assert (sizeof i386fbsd_sigtramp_start + == sizeof i386fbsd_osigtramp_start); +gdb_static_assert (sizeof i386fbsd_sigtramp_middle + == sizeof i386fbsd_freebsd4_sigtramp_middle); +gdb_static_assert (sizeof i386fbsd_sigtramp_middle + == sizeof i386fbsd_osigtramp_middle); +gdb_static_assert (sizeof i386fbsd_sigtramp_end + == sizeof i386fbsd_freebsd4_sigtramp_end); +gdb_static_assert (sizeof i386fbsd_sigtramp_end + == sizeof i386fbsd_osigtramp_end); + +/* We assume that the middle is the largest chunk below. */ +gdb_static_assert (sizeof i386fbsd_sigtramp_middle + > sizeof i386fbsd_sigtramp_start); +gdb_static_assert (sizeof i386fbsd_sigtramp_middle + > sizeof i386fbsd_sigtramp_end); + +static int +i386fbsd_sigtramp_p (struct frame_info *this_frame) +{ + CORE_ADDR pc = get_frame_pc (this_frame); + gdb_byte buf[sizeof i386fbsd_sigtramp_middle]; + const gdb_byte *middle, *end; + + /* Look for a matching start. */ + if (!safe_frame_unwind_memory (this_frame, pc, buf, + sizeof i386fbsd_sigtramp_start)) + return 0; + if (memcmp (buf, i386fbsd_sigtramp_start, sizeof i386fbsd_sigtramp_start) + == 0) + { + middle = i386fbsd_sigtramp_middle; + end = i386fbsd_sigtramp_end; + } + else if (memcmp (buf, i386fbsd_freebsd4_sigtramp_start, + sizeof i386fbsd_freebsd4_sigtramp_start) == 0) + { + middle = i386fbsd_freebsd4_sigtramp_middle; + end = i386fbsd_freebsd4_sigtramp_end; + } + else if (memcmp (buf, i386fbsd_osigtramp_start, + sizeof i386fbsd_osigtramp_start) == 0) + { + middle = i386fbsd_osigtramp_middle; + end = i386fbsd_osigtramp_end; + } + else + return 0; + + /* Since the end is shorter than the middle, check for a matching end + next. */ + pc += sizeof i386fbsd_sigtramp_start; + if (!safe_frame_unwind_memory (this_frame, pc, buf, + sizeof i386fbsd_sigtramp_end)) + return 0; + if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) == 0) + return 1; + + /* If the end didn't match, check for a matching middle. */ + if (!safe_frame_unwind_memory (this_frame, pc, buf, + sizeof i386fbsd_sigtramp_middle)) + return 0; + if (memcmp (buf, middle, sizeof i386fbsd_sigtramp_middle) != 0) + return 0; + + /* The middle matched, check for a matching end. */ + pc += sizeof i386fbsd_sigtramp_middle; + if (!safe_frame_unwind_memory (this_frame, pc, buf, + sizeof i386fbsd_sigtramp_end)) + return 0; + if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) != 0) + return 0; + + return 1; +} + +/* FreeBSD 3.0-RELEASE or later. */ + +/* From <machine/reg.h>. */ +static int i386fbsd_r_reg_offset[] = +{ + 9 * 4, 8 * 4, 7 * 4, 6 * 4, /* %eax, %ecx, %edx, %ebx */ + 15 * 4, 4 * 4, /* %esp, %ebp */ + 3 * 4, 2 * 4, /* %esi, %edi */ + 12 * 4, 14 * 4, /* %eip, %eflags */ + 13 * 4, 16 * 4, /* %cs, %ss */ + 1 * 4, 0 * 4, -1, -1 /* %ds, %es, %fs, %gs */ +}; + +/* Sigtramp routine location. */ +CORE_ADDR i386fbsd_sigtramp_start_addr; +CORE_ADDR i386fbsd_sigtramp_end_addr; + +/* From <machine/signal.h>. */ +int i386fbsd_sc_reg_offset[] = +{ + 8 + 14 * 4, /* %eax */ + 8 + 13 * 4, /* %ecx */ + 8 + 12 * 4, /* %edx */ + 8 + 11 * 4, /* %ebx */ + 8 + 0 * 4, /* %esp */ + 8 + 1 * 4, /* %ebp */ + 8 + 10 * 4, /* %esi */ + 8 + 9 * 4, /* %edi */ + 8 + 3 * 4, /* %eip */ + 8 + 4 * 4, /* %eflags */ + 8 + 7 * 4, /* %cs */ + 8 + 8 * 4, /* %ss */ + 8 + 6 * 4, /* %ds */ + 8 + 5 * 4, /* %es */ + 8 + 15 * 4, /* %fs */ + 8 + 16 * 4 /* %gs */ +}; + +/* From /usr/src/lib/libc/i386/gen/_setjmp.S. */ +static int i386fbsd_jmp_buf_reg_offset[] = +{ + -1, /* %eax */ + -1, /* %ecx */ + -1, /* %edx */ + 1 * 4, /* %ebx */ + 2 * 4, /* %esp */ + 3 * 4, /* %ebp */ + 4 * 4, /* %esi */ + 5 * 4, /* %edi */ + 0 * 4 /* %eip */ +}; + +/* Get XSAVE extended state xcr0 from core dump. */ + +uint64_t +i386fbsd_core_read_xcr0 (bfd *abfd) +{ + asection *xstate = bfd_get_section_by_name (abfd, ".reg-xstate"); + uint64_t xcr0; + + if (xstate) + { + size_t size = bfd_section_size (abfd, xstate); + + /* Check extended state size. */ + if (size < X86_XSTATE_AVX_SIZE) + xcr0 = X86_XSTATE_SSE_MASK; + else + { + char contents[8]; + + if (! bfd_get_section_contents (abfd, xstate, contents, + I386_FBSD_XSAVE_XCR0_OFFSET, + 8)) + { + warning (_("Couldn't read `xcr0' bytes from " + "`.reg-xstate' section in core file.")); + return 0; + } + + xcr0 = bfd_get_64 (abfd, contents); + } + } + else + xcr0 = 0; + + return xcr0; +} + +/* Implement the core_read_description gdbarch method. */ + +static const struct target_desc * +i386fbsd_core_read_description (struct gdbarch *gdbarch, + struct target_ops *target, + bfd *abfd) +{ + return i386_target_description (i386fbsd_core_read_xcr0 (abfd)); +} + +/* Similar to i386_supply_fpregset, but use XSAVE extended state. */ + +static void +i386fbsd_supply_xstateregset (const struct regset *regset, + struct regcache *regcache, int regnum, + const void *xstateregs, size_t len) +{ + i387_supply_xsave (regcache, regnum, xstateregs); +} + +/* Similar to i386_collect_fpregset, but use XSAVE extended state. */ + +static void +i386fbsd_collect_xstateregset (const struct regset *regset, + const struct regcache *regcache, + int regnum, void *xstateregs, size_t len) +{ + i387_collect_xsave (regcache, regnum, xstateregs, 1); +} + +/* Register set definitions. */ + +static const struct regset i386fbsd_xstateregset = + { + NULL, + i386fbsd_supply_xstateregset, + i386fbsd_collect_xstateregset + }; + +/* Iterate over core file register note sections. */ + +static void +i386fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch, + iterate_over_regset_sections_cb *cb, + void *cb_data, + const struct regcache *regcache) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + cb (".reg", tdep->sizeof_gregset, &i386_gregset, NULL, cb_data); + cb (".reg2", tdep->sizeof_fpregset, &i386_fpregset, NULL, cb_data); + + if (tdep->xcr0 & X86_XSTATE_AVX) + cb (".reg-xstate", X86_XSTATE_SIZE(tdep->xcr0), + &i386fbsd_xstateregset, "XSAVE extended state", cb_data); +} + +static void +i386fbsd_supply_uthread (struct regcache *regcache, + int regnum, CORE_ADDR addr) +{ + gdb_byte buf[4]; + int i; + + gdb_assert (regnum >= -1); + + for (i = 0; i < ARRAY_SIZE (i386fbsd_jmp_buf_reg_offset); i++) + { + if (i386fbsd_jmp_buf_reg_offset[i] != -1 + && (regnum == -1 || regnum == i)) + { + read_memory (addr + i386fbsd_jmp_buf_reg_offset[i], buf, 4); + regcache_raw_supply (regcache, i, buf); + } + } +} + +static void +i386fbsd_collect_uthread (const struct regcache *regcache, + int regnum, CORE_ADDR addr) +{ + gdb_byte buf[4]; + int i; + + gdb_assert (regnum >= -1); + + for (i = 0; i < ARRAY_SIZE (i386fbsd_jmp_buf_reg_offset); i++) + { + if (i386fbsd_jmp_buf_reg_offset[i] != -1 + && (regnum == -1 || regnum == i)) + { + regcache_raw_collect (regcache, i, buf); + write_memory (addr + i386fbsd_jmp_buf_reg_offset[i], buf, 4); + } + } +} + +static void +i386fbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + /* Obviously FreeBSD is BSD-based. */ + i386bsd_init_abi (info, gdbarch); + + /* FreeBSD has a different `struct reg', and reserves some space for + its FPU emulator in `struct fpreg'. */ + tdep->gregset_reg_offset = i386fbsd_r_reg_offset; + tdep->gregset_num_regs = ARRAY_SIZE (i386fbsd_r_reg_offset); + tdep->sizeof_gregset = 18 * 4; + tdep->sizeof_fpregset = 176; + + /* FreeBSD uses -freg-struct-return by default. */ + tdep->struct_return = reg_struct_return; + + tdep->sigtramp_p = i386fbsd_sigtramp_p; + + /* FreeBSD uses a different memory layout. */ + tdep->sigtramp_start = i386fbsd_sigtramp_start_addr; + tdep->sigtramp_end = i386fbsd_sigtramp_end_addr; + + /* FreeBSD has a more complete `struct sigcontext'. */ + tdep->sc_reg_offset = i386fbsd_sc_reg_offset; + tdep->sc_num_regs = ARRAY_SIZE (i386fbsd_sc_reg_offset); + + /* FreeBSD provides a user-level threads implementation. */ + bsd_uthread_set_supply_uthread (gdbarch, i386fbsd_supply_uthread); + bsd_uthread_set_collect_uthread (gdbarch, i386fbsd_collect_uthread); +} + +static void +i386fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) +{ + /* It's almost identical to FreeBSD a.out. */ + i386fbsdaout_init_abi (info, gdbarch); + + /* Except that it uses ELF. */ + i386_elf_init_abi (info, gdbarch); + + /* FreeBSD ELF uses SVR4-style shared libraries. */ + set_solib_svr4_fetch_link_map_offsets + (gdbarch, svr4_ilp32_fetch_link_map_offsets); +} + +/* FreeBSD 4.0-RELEASE or later. */ + +/* From <machine/reg.h>. */ +static int i386fbsd4_r_reg_offset[] = +{ + 10 * 4, 9 * 4, 8 * 4, 7 * 4, /* %eax, %ecx, %edx, %ebx */ + 16 * 4, 5 * 4, /* %esp, %ebp */ + 4 * 4, 3 * 4, /* %esi, %edi */ + 13 * 4, 15 * 4, /* %eip, %eflags */ + 14 * 4, 17 * 4, /* %cs, %ss */ + 2 * 4, 1 * 4, 0 * 4, 18 * 4 /* %ds, %es, %fs, %gs */ +}; + +/* From <machine/signal.h>. */ +int i386fbsd4_sc_reg_offset[] = +{ + 20 + 11 * 4, /* %eax */ + 20 + 10 * 4, /* %ecx */ + 20 + 9 * 4, /* %edx */ + 20 + 8 * 4, /* %ebx */ + 20 + 17 * 4, /* %esp */ + 20 + 6 * 4, /* %ebp */ + 20 + 5 * 4, /* %esi */ + 20 + 4 * 4, /* %edi */ + 20 + 14 * 4, /* %eip */ + 20 + 16 * 4, /* %eflags */ + 20 + 15 * 4, /* %cs */ + 20 + 18 * 4, /* %ss */ + 20 + 3 * 4, /* %ds */ + 20 + 2 * 4, /* %es */ + 20 + 1 * 4, /* %fs */ + 20 + 0 * 4 /* %gs */ +}; + +static void +i386fbsd4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + /* Generic FreeBSD support. */ + fbsd_init_abi (info, gdbarch); + + /* Inherit stuff from older releases. We assume that FreeBSD + 4.0-RELEASE always uses ELF. */ + i386fbsd_init_abi (info, gdbarch); + + /* FreeBSD 4.0 introduced a new `struct reg'. */ + tdep->gregset_reg_offset = i386fbsd4_r_reg_offset; + tdep->gregset_num_regs = ARRAY_SIZE (i386fbsd4_r_reg_offset); + tdep->sizeof_gregset = 19 * 4; + + /* FreeBSD 4.0 introduced a new `struct sigcontext'. */ + tdep->sc_reg_offset = i386fbsd4_sc_reg_offset; + tdep->sc_num_regs = ARRAY_SIZE (i386fbsd4_sc_reg_offset); + + tdep->xsave_xcr0_offset = I386_FBSD_XSAVE_XCR0_OFFSET; + + /* Iterate over core file register note sections. */ + set_gdbarch_iterate_over_regset_sections + (gdbarch, i386fbsd_iterate_over_regset_sections); + + set_gdbarch_core_read_description (gdbarch, + i386fbsd_core_read_description); +} + + +/* Provide a prototype to silence -Wmissing-prototypes. */ +void _initialize_i386fbsd_tdep (void); + +void +_initialize_i386fbsd_tdep (void) +{ + gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_FREEBSD_AOUT, + i386fbsdaout_init_abi); + gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_FREEBSD_ELF, + i386fbsd4_init_abi); +} |