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- /* Target-dependent code for FreeBSD/i386.
- Copyright (C) 2003-2022 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 "osabi.h"
- #include "regcache.h"
- #include "regset.h"
- #include "trad-frame.h"
- #include "tramp-frame.h"
- #include "i386-fbsd-tdep.h"
- #include "gdbsupport/x86-xstate.h"
- #include "i386-tdep.h"
- #include "i387-tdep.h"
- #include "fbsd-tdep.h"
- #include "solib-svr4.h"
- #include "inferior.h"
- /* The general-purpose regset consists of 19 32-bit slots. */
- #define I386_FBSD_SIZEOF_GREGSET (19 * 4)
- /* The segment base register set consists of 2 32-bit registers. */
- #define I386_FBSD_SIZEOF_SEGBASES_REGSET (2 * 4)
- /* Register maps. */
- static const struct regcache_map_entry i386_fbsd_gregmap[] =
- {
- { 1, I386_FS_REGNUM, 4 },
- { 1, I386_ES_REGNUM, 4 },
- { 1, I386_DS_REGNUM, 4 },
- { 1, I386_EDI_REGNUM, 0 },
- { 1, I386_ESI_REGNUM, 0 },
- { 1, I386_EBP_REGNUM, 0 },
- { 1, REGCACHE_MAP_SKIP, 4 }, /* isp */
- { 1, I386_EBX_REGNUM, 0 },
- { 1, I386_EDX_REGNUM, 0 },
- { 1, I386_ECX_REGNUM, 0 },
- { 1, I386_EAX_REGNUM, 0 },
- { 1, REGCACHE_MAP_SKIP, 4 }, /* trapno */
- { 1, REGCACHE_MAP_SKIP, 4 }, /* err */
- { 1, I386_EIP_REGNUM, 0 },
- { 1, I386_CS_REGNUM, 4 },
- { 1, I386_EFLAGS_REGNUM, 0 },
- { 1, I386_ESP_REGNUM, 0 },
- { 1, I386_SS_REGNUM, 4 },
- { 1, I386_GS_REGNUM, 4 },
- { 0 }
- };
- static const struct regcache_map_entry i386_fbsd_segbases_regmap[] =
- {
- { 1, I386_FSBASE_REGNUM, 0 },
- { 1, I386_GSBASE_REGNUM, 0 },
- { 0 }
- };
- /* This layout including fsbase and gsbase was adopted in FreeBSD
- 8.0. */
- static const struct regcache_map_entry i386_fbsd_mcregmap[] =
- {
- { 1, REGCACHE_MAP_SKIP, 4 }, /* mc_onstack */
- { 1, I386_GS_REGNUM, 4 },
- { 1, I386_FS_REGNUM, 4 },
- { 1, I386_ES_REGNUM, 4 },
- { 1, I386_DS_REGNUM, 4 },
- { 1, I386_EDI_REGNUM, 0 },
- { 1, I386_ESI_REGNUM, 0 },
- { 1, I386_EBP_REGNUM, 0 },
- { 1, REGCACHE_MAP_SKIP, 4 }, /* isp */
- { 1, I386_EBX_REGNUM, 0 },
- { 1, I386_EDX_REGNUM, 0 },
- { 1, I386_ECX_REGNUM, 0 },
- { 1, I386_EAX_REGNUM, 0 },
- { 1, REGCACHE_MAP_SKIP, 4 }, /* mc_trapno */
- { 1, REGCACHE_MAP_SKIP, 4 }, /* mc_err */
- { 1, I386_EIP_REGNUM, 0 },
- { 1, I386_CS_REGNUM, 4 },
- { 1, I386_EFLAGS_REGNUM, 0 },
- { 1, I386_ESP_REGNUM, 0 },
- { 1, I386_SS_REGNUM, 4 },
- { 1, REGCACHE_MAP_SKIP, 4 }, /* mc_len */
- { 1, REGCACHE_MAP_SKIP, 4 }, /* mc_fpformat */
- { 1, REGCACHE_MAP_SKIP, 4 }, /* mc_ownedfp */
- { 1, REGCACHE_MAP_SKIP, 4 }, /* mc_flags */
- { 128, REGCACHE_MAP_SKIP, 4 },/* mc_fpstate */
- { 1, I386_FSBASE_REGNUM, 0 },
- { 1, I386_GSBASE_REGNUM, 0 },
- { 0 }
- };
- /* Register set definitions. */
- const struct regset i386_fbsd_gregset =
- {
- i386_fbsd_gregmap, regcache_supply_regset, regcache_collect_regset
- };
- const struct regset i386_fbsd_segbases_regset =
- {
- i386_fbsd_segbases_regmap, regcache_supply_regset, regcache_collect_regset
- };
- /* Support for signal handlers. */
- /* In a signal frame, esp points to a 'struct sigframe' which is
- defined as:
- struct sigframe {
- register_t sf_signum;
- register_t sf_siginfo;
- register_t sf_ucontext;
- register_t sf_addr;
- union {
- __siginfohandler_t *sf_action;
- __sighandler_t *sf_handler;
- } sf_ahu;
- ucontext_t sf_uc;
- ...
- }
- ucontext_t is defined as:
- struct __ucontext {
- sigset_t uc_sigmask;
- mcontext_t uc_mcontext;
- ...
- };
- The mcontext_t contains the general purpose register set as well
- as the floating point or XSAVE state. */
- /* NB: There is a 12 byte padding hole between sf_ahu and sf_uc. */
- #define I386_SIGFRAME_UCONTEXT_OFFSET 32
- #define I386_UCONTEXT_MCONTEXT_OFFSET 16
- #define I386_SIZEOF_MCONTEXT_T 640
- /* Implement the "init" method of struct tramp_frame. */
- static void
- i386_fbsd_sigframe_init (const struct tramp_frame *self,
- struct frame_info *this_frame,
- struct trad_frame_cache *this_cache,
- CORE_ADDR func)
- {
- CORE_ADDR sp = get_frame_register_unsigned (this_frame, I386_ESP_REGNUM);
- CORE_ADDR mcontext_addr
- = (sp
- + I386_SIGFRAME_UCONTEXT_OFFSET
- + I386_UCONTEXT_MCONTEXT_OFFSET);
- trad_frame_set_reg_regmap (this_cache, i386_fbsd_mcregmap, mcontext_addr,
- I386_SIZEOF_MCONTEXT_T);
- /* Don't bother with floating point or XSAVE state for now. The
- current helper routines for parsing FXSAVE and XSAVE state only
- work with regcaches. This could perhaps create a temporary
- regcache, collect the register values from mc_fpstate and
- mc_xfpustate, and then set register values in the trad_frame. */
- trad_frame_set_id (this_cache, frame_id_build (sp, func));
- }
- static const struct tramp_frame i386_fbsd_sigframe =
- {
- SIGTRAMP_FRAME,
- 1,
- {
- {0x8d, ULONGEST_MAX}, /* lea SIGF_UC(%esp),%eax */
- {0x44, ULONGEST_MAX},
- {0x24, ULONGEST_MAX},
- {0x20, ULONGEST_MAX},
- {0x50, ULONGEST_MAX}, /* pushl %eax */
- {0xf7, ULONGEST_MAX}, /* testl $PSL_VM,UC_EFLAGS(%eax) */
- {0x40, ULONGEST_MAX},
- {0x54, ULONGEST_MAX},
- {0x00, ULONGEST_MAX},
- {0x00, ULONGEST_MAX},
- {0x02, ULONGEST_MAX},
- {0x00, ULONGEST_MAX},
- {0x75, ULONGEST_MAX}, /* jne +3 */
- {0x03, ULONGEST_MAX},
- {0x8e, ULONGEST_MAX}, /* mov UC_GS(%eax),%gs */
- {0x68, ULONGEST_MAX},
- {0x14, ULONGEST_MAX},
- {0xb8, ULONGEST_MAX}, /* movl $SYS_sigreturn,%eax */
- {0xa1, ULONGEST_MAX},
- {0x01, ULONGEST_MAX},
- {0x00, ULONGEST_MAX},
- {0x00, ULONGEST_MAX},
- {0x50, ULONGEST_MAX}, /* pushl %eax */
- {0xcd, ULONGEST_MAX}, /* int $0x80 */
- {0x80, ULONGEST_MAX},
- {TRAMP_SENTINEL_INSN, ULONGEST_MAX}
- },
- i386_fbsd_sigframe_init
- };
- /* FreeBSD/i386 binaries running under an amd64 kernel use a different
- trampoline. This trampoline differs from the i386 kernel trampoline
- in that it omits a middle section that conditionally restores
- %gs. */
- static const struct tramp_frame i386_fbsd64_sigframe =
- {
- SIGTRAMP_FRAME,
- 1,
- {
- {0x8d, ULONGEST_MAX}, /* lea SIGF_UC(%esp),%eax */
- {0x44, ULONGEST_MAX},
- {0x24, ULONGEST_MAX},
- {0x20, ULONGEST_MAX},
- {0x50, ULONGEST_MAX}, /* pushl %eax */
- {0xb8, ULONGEST_MAX}, /* movl $SYS_sigreturn,%eax */
- {0xa1, ULONGEST_MAX},
- {0x01, ULONGEST_MAX},
- {0x00, ULONGEST_MAX},
- {0x00, ULONGEST_MAX},
- {0x50, ULONGEST_MAX}, /* pushl %eax */
- {0xcd, ULONGEST_MAX}, /* int $0x80 */
- {0x80, ULONGEST_MAX},
- {TRAMP_SENTINEL_INSN, ULONGEST_MAX}
- },
- i386_fbsd_sigframe_init
- };
- /* 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 (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 X86_XSTATE_SSE_MASK;
- }
- xcr0 = bfd_get_64 (abfd, contents);
- }
- }
- else
- xcr0 = X86_XSTATE_SSE_MASK;
- 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), true);
- }
- /* 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)
- {
- i386_gdbarch_tdep *tdep = (i386_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- cb (".reg", I386_FBSD_SIZEOF_GREGSET, I386_FBSD_SIZEOF_GREGSET,
- &i386_fbsd_gregset, NULL, cb_data);
- cb (".reg2", tdep->sizeof_fpregset, tdep->sizeof_fpregset, &i386_fpregset,
- NULL, cb_data);
- cb (".reg-x86-segbases", I386_FBSD_SIZEOF_SEGBASES_REGSET,
- I386_FBSD_SIZEOF_SEGBASES_REGSET, &i386_fbsd_segbases_regset,
- "segment bases", cb_data);
- if (tdep->xcr0 & X86_XSTATE_AVX)
- cb (".reg-xstate", X86_XSTATE_SIZE (tdep->xcr0),
- X86_XSTATE_SIZE (tdep->xcr0), &i386fbsd_xstateregset,
- "XSAVE extended state", cb_data);
- }
- /* Implement the get_thread_local_address gdbarch method. */
- static CORE_ADDR
- i386fbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid,
- CORE_ADDR lm_addr, CORE_ADDR offset)
- {
- struct regcache *regcache;
- regcache = get_thread_arch_regcache (current_inferior ()->process_target (),
- ptid, gdbarch);
- target_fetch_registers (regcache, I386_GSBASE_REGNUM);
- ULONGEST gsbase;
- if (regcache->cooked_read (I386_GSBASE_REGNUM, &gsbase) != REG_VALID)
- error (_("Unable to fetch %%gsbase"));
- CORE_ADDR dtv_addr = gsbase + gdbarch_ptr_bit (gdbarch) / 8;
- return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset);
- }
- static void
- i386fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
- {
- i386_gdbarch_tdep *tdep = (i386_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- /* Generic FreeBSD support. */
- fbsd_init_abi (info, gdbarch);
- /* Obviously FreeBSD is BSD-based. */
- i386bsd_init_abi (info, gdbarch);
- /* FreeBSD reserves some space for its FPU emulator in
- `struct fpreg'. */
- tdep->sizeof_fpregset = 176;
- /* FreeBSD uses -freg-struct-return by default. */
- tdep->struct_return = reg_struct_return;
- tramp_frame_prepend_unwinder (gdbarch, &i386_fbsd_sigframe);
- tramp_frame_prepend_unwinder (gdbarch, &i386_fbsd64_sigframe);
- i386_elf_init_abi (info, gdbarch);
- 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);
- /* FreeBSD uses SVR4-style shared libraries. */
- set_solib_svr4_fetch_link_map_offsets
- (gdbarch, svr4_ilp32_fetch_link_map_offsets);
- set_gdbarch_fetch_tls_load_module_address (gdbarch,
- svr4_fetch_objfile_link_map);
- set_gdbarch_get_thread_local_address (gdbarch,
- i386fbsd_get_thread_local_address);
- }
- void _initialize_i386fbsd_tdep ();
- void
- _initialize_i386fbsd_tdep ()
- {
- gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_FREEBSD,
- i386fbsd_init_abi);
- }
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