123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462 |
- /* Target-dependent code for OpenBSD/amd64.
- 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 "frame.h"
- #include "frame-unwind.h"
- #include "gdbcore.h"
- #include "symtab.h"
- #include "objfiles.h"
- #include "osabi.h"
- #include "regcache.h"
- #include "regset.h"
- #include "target.h"
- #include "trad-frame.h"
- #include "obsd-tdep.h"
- #include "amd64-tdep.h"
- #include "i387-tdep.h"
- #include "gdbsupport/x86-xstate.h"
- #include "solib-svr4.h"
- #include "bsd-uthread.h"
- /* Support for signal handlers. */
- /* Default page size. */
- static const int amd64obsd_page_size = 4096;
- /* Return whether THIS_FRAME corresponds to an OpenBSD sigtramp
- routine. */
- static int
- amd64obsd_sigtramp_p (struct frame_info *this_frame)
- {
- CORE_ADDR pc = get_frame_pc (this_frame);
- CORE_ADDR start_pc = (pc & ~(amd64obsd_page_size - 1));
- const gdb_byte osigreturn[] =
- {
- 0x48, 0xc7, 0xc0,
- 0x67, 0x00, 0x00, 0x00, /* movq $SYS_sigreturn, %rax */
- 0xcd, 0x80 /* int $0x80 */
- };
- const gdb_byte sigreturn[] =
- {
- 0x48, 0xc7, 0xc0,
- 0x67, 0x00, 0x00, 0x00, /* movq $SYS_sigreturn, %rax */
- 0x0f, 0x05 /* syscall */
- };
- size_t buflen = (sizeof sigreturn) + 1;
- gdb_byte *buf;
- const char *name;
- /* If the function has a valid symbol name, it isn't a
- trampoline. */
- find_pc_partial_function (pc, &name, NULL, NULL);
- if (name != NULL)
- return 0;
- /* If the function lives in a valid section (even without a starting
- point) it isn't a trampoline. */
- if (find_pc_section (pc) != NULL)
- return 0;
- /* If we can't read the instructions at START_PC, return zero. */
- buf = (gdb_byte *) alloca ((sizeof sigreturn) + 1);
- if (!safe_frame_unwind_memory (this_frame, start_pc + 6, {buf, buflen}))
- return 0;
- /* Check for sigreturn(2). Depending on how the assembler encoded
- the `movq %rsp, %rdi' instruction, the code starts at offset 6 or
- 7. OpenBSD 5.0 and later use the `syscall' instruction. Older
- versions use `int $0x80'. Check for both. */
- if (memcmp (buf, sigreturn, sizeof sigreturn)
- && memcmp (buf + 1, sigreturn, sizeof sigreturn)
- && memcmp (buf, osigreturn, sizeof osigreturn)
- && memcmp (buf + 1, osigreturn, sizeof osigreturn))
- return 0;
- return 1;
- }
- /* Assuming THIS_FRAME is for a BSD sigtramp routine, return the
- address of the associated sigcontext structure. */
- static CORE_ADDR
- amd64obsd_sigcontext_addr (struct frame_info *this_frame)
- {
- CORE_ADDR pc = get_frame_pc (this_frame);
- ULONGEST offset = (pc & (amd64obsd_page_size - 1));
- /* The %rsp register points at `struct sigcontext' upon entry of a
- signal trampoline. The relevant part of the trampoline is
- call *%rax
- movq %rsp, %rdi
- pushq %rdi
- movq $SYS_sigreturn,%rax
- int $0x80
- (see /usr/src/sys/arch/amd64/amd64/locore.S). The `pushq'
- instruction clobbers %rsp, but its value is saved in `%rdi'. */
- if (offset > 5)
- return get_frame_register_unsigned (this_frame, AMD64_RDI_REGNUM);
- else
- return get_frame_register_unsigned (this_frame, AMD64_RSP_REGNUM);
- }
- /* OpenBSD 3.5 or later. */
- /* Mapping between the general-purpose registers in `struct reg'
- format and GDB's register cache layout. */
- /* From <machine/reg.h>. */
- int amd64obsd_r_reg_offset[] =
- {
- 14 * 8, /* %rax */
- 13 * 8, /* %rbx */
- 3 * 8, /* %rcx */
- 2 * 8, /* %rdx */
- 1 * 8, /* %rsi */
- 0 * 8, /* %rdi */
- 12 * 8, /* %rbp */
- 15 * 8, /* %rsp */
- 4 * 8, /* %r8 .. */
- 5 * 8,
- 6 * 8,
- 7 * 8,
- 8 * 8,
- 9 * 8,
- 10 * 8,
- 11 * 8, /* ... %r15 */
- 16 * 8, /* %rip */
- 17 * 8, /* %eflags */
- 18 * 8, /* %cs */
- 19 * 8, /* %ss */
- 20 * 8, /* %ds */
- 21 * 8, /* %es */
- 22 * 8, /* %fs */
- 23 * 8 /* %gs */
- };
- /* From <machine/signal.h>. */
- static int amd64obsd_sc_reg_offset[] =
- {
- 14 * 8, /* %rax */
- 13 * 8, /* %rbx */
- 3 * 8, /* %rcx */
- 2 * 8, /* %rdx */
- 1 * 8, /* %rsi */
- 0 * 8, /* %rdi */
- 12 * 8, /* %rbp */
- 24 * 8, /* %rsp */
- 4 * 8, /* %r8 ... */
- 5 * 8,
- 6 * 8,
- 7 * 8,
- 8 * 8,
- 9 * 8,
- 10 * 8,
- 11 * 8, /* ... %r15 */
- 21 * 8, /* %rip */
- 23 * 8, /* %eflags */
- 22 * 8, /* %cs */
- 25 * 8, /* %ss */
- 18 * 8, /* %ds */
- 17 * 8, /* %es */
- 16 * 8, /* %fs */
- 15 * 8 /* %gs */
- };
- /* From /usr/src/lib/libpthread/arch/amd64/uthread_machdep.c. */
- static int amd64obsd_uthread_reg_offset[] =
- {
- 19 * 8, /* %rax */
- 16 * 8, /* %rbx */
- 18 * 8, /* %rcx */
- 17 * 8, /* %rdx */
- 14 * 8, /* %rsi */
- 13 * 8, /* %rdi */
- 15 * 8, /* %rbp */
- -1, /* %rsp */
- 12 * 8, /* %r8 ... */
- 11 * 8,
- 10 * 8,
- 9 * 8,
- 8 * 8,
- 7 * 8,
- 6 * 8,
- 5 * 8, /* ... %r15 */
- 20 * 8, /* %rip */
- 4 * 8, /* %eflags */
- 21 * 8, /* %cs */
- -1, /* %ss */
- 3 * 8, /* %ds */
- 2 * 8, /* %es */
- 1 * 8, /* %fs */
- 0 * 8 /* %gs */
- };
- /* Offset within the thread structure where we can find the saved
- stack pointer (%esp). */
- #define AMD64OBSD_UTHREAD_RSP_OFFSET 400
- static void
- amd64obsd_supply_uthread (struct regcache *regcache,
- int regnum, CORE_ADDR addr)
- {
- struct gdbarch *gdbarch = regcache->arch ();
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- CORE_ADDR sp_addr = addr + AMD64OBSD_UTHREAD_RSP_OFFSET;
- CORE_ADDR sp = 0;
- gdb_byte buf[8];
- int i;
- gdb_assert (regnum >= -1);
- if (regnum == -1 || regnum == AMD64_RSP_REGNUM)
- {
- int offset;
- /* Fetch stack pointer from thread structure. */
- sp = read_memory_unsigned_integer (sp_addr, 8, byte_order);
- /* Adjust the stack pointer such that it looks as if we just
- returned from _thread_machdep_switch. */
- offset = amd64obsd_uthread_reg_offset[AMD64_RIP_REGNUM] + 8;
- store_unsigned_integer (buf, 8, byte_order, sp + offset);
- regcache->raw_supply (AMD64_RSP_REGNUM, buf);
- }
- for (i = 0; i < ARRAY_SIZE (amd64obsd_uthread_reg_offset); i++)
- {
- if (amd64obsd_uthread_reg_offset[i] != -1
- && (regnum == -1 || regnum == i))
- {
- /* Fetch stack pointer from thread structure (if we didn't
- do so already). */
- if (sp == 0)
- sp = read_memory_unsigned_integer (sp_addr, 8, byte_order);
- /* Read the saved register from the stack frame. */
- read_memory (sp + amd64obsd_uthread_reg_offset[i], buf, 8);
- regcache->raw_supply (i, buf);
- }
- }
- }
- static void
- amd64obsd_collect_uthread (const struct regcache *regcache,
- int regnum, CORE_ADDR addr)
- {
- struct gdbarch *gdbarch = regcache->arch ();
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- CORE_ADDR sp_addr = addr + AMD64OBSD_UTHREAD_RSP_OFFSET;
- CORE_ADDR sp = 0;
- gdb_byte buf[8];
- int i;
- gdb_assert (regnum >= -1);
- if (regnum == -1 || regnum == AMD64_RSP_REGNUM)
- {
- int offset;
- /* Calculate the stack pointer (frame pointer) that will be
- stored into the thread structure. */
- offset = amd64obsd_uthread_reg_offset[AMD64_RIP_REGNUM] + 8;
- regcache->raw_collect (AMD64_RSP_REGNUM, buf);
- sp = extract_unsigned_integer (buf, 8, byte_order) - offset;
- /* Store the stack pointer. */
- write_memory_unsigned_integer (sp_addr, 8, byte_order, sp);
- /* The stack pointer was (potentially) modified. Make sure we
- build a proper stack frame. */
- regnum = -1;
- }
- for (i = 0; i < ARRAY_SIZE (amd64obsd_uthread_reg_offset); i++)
- {
- if (amd64obsd_uthread_reg_offset[i] != -1
- && (regnum == -1 || regnum == i))
- {
- /* Fetch stack pointer from thread structure (if we didn't
- calculate it already). */
- if (sp == 0)
- sp = read_memory_unsigned_integer (sp_addr, 8, byte_order);
- /* Write the register into the stack frame. */
- regcache->raw_collect (i, buf);
- write_memory (sp + amd64obsd_uthread_reg_offset[i], buf, 8);
- }
- }
- }
- /* Kernel debugging support. */
- /* From <machine/frame.h>. Easy since `struct trapframe' matches
- `struct sigcontext'. */
- #define amd64obsd_tf_reg_offset amd64obsd_sc_reg_offset
- static struct trad_frame_cache *
- amd64obsd_trapframe_cache (struct frame_info *this_frame, void **this_cache)
- {
- struct gdbarch *gdbarch = get_frame_arch (this_frame);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- struct trad_frame_cache *cache;
- CORE_ADDR func, sp, addr;
- ULONGEST cs;
- const char *name;
- int i;
- if (*this_cache)
- return (struct trad_frame_cache *) *this_cache;
- cache = trad_frame_cache_zalloc (this_frame);
- *this_cache = cache;
- func = get_frame_func (this_frame);
- sp = get_frame_register_unsigned (this_frame, AMD64_RSP_REGNUM);
- find_pc_partial_function (func, &name, NULL, NULL);
- if (name && startswith (name, "Xintr"))
- addr = sp + 8; /* It's an interrupt frame. */
- else
- addr = sp;
- for (i = 0; i < ARRAY_SIZE (amd64obsd_tf_reg_offset); i++)
- if (amd64obsd_tf_reg_offset[i] != -1)
- trad_frame_set_reg_addr (cache, i, addr + amd64obsd_tf_reg_offset[i]);
- /* Read %cs from trap frame. */
- addr += amd64obsd_tf_reg_offset[AMD64_CS_REGNUM];
- cs = read_memory_unsigned_integer (addr, 8, byte_order);
- if ((cs & I386_SEL_RPL) == I386_SEL_UPL)
- {
- /* Trap from user space; terminate backtrace. */
- trad_frame_set_id (cache, outer_frame_id);
- }
- else
- {
- /* Construct the frame ID using the function start. */
- trad_frame_set_id (cache, frame_id_build (sp + 16, func));
- }
- return cache;
- }
- static void
- amd64obsd_trapframe_this_id (struct frame_info *this_frame,
- void **this_cache, struct frame_id *this_id)
- {
- struct trad_frame_cache *cache =
- amd64obsd_trapframe_cache (this_frame, this_cache);
-
- trad_frame_get_id (cache, this_id);
- }
- static struct value *
- amd64obsd_trapframe_prev_register (struct frame_info *this_frame,
- void **this_cache, int regnum)
- {
- struct trad_frame_cache *cache =
- amd64obsd_trapframe_cache (this_frame, this_cache);
- return trad_frame_get_register (cache, this_frame, regnum);
- }
- static int
- amd64obsd_trapframe_sniffer (const struct frame_unwind *self,
- struct frame_info *this_frame,
- void **this_prologue_cache)
- {
- ULONGEST cs;
- const char *name;
- /* Check Current Privilege Level and bail out if we're not executing
- in kernel space. */
- cs = get_frame_register_unsigned (this_frame, AMD64_CS_REGNUM);
- if ((cs & I386_SEL_RPL) == I386_SEL_UPL)
- return 0;
- find_pc_partial_function (get_frame_pc (this_frame), &name, NULL, NULL);
- return (name && ((strcmp (name, "calltrap") == 0)
- || (strcmp (name, "osyscall1") == 0)
- || (strcmp (name, "Xsyscall") == 0)
- || (startswith (name, "Xintr"))));
- }
- static const struct frame_unwind amd64obsd_trapframe_unwind =
- {
- /* FIXME: kettenis/20051219: This really is more like an interrupt
- frame, but SIGTRAMP_FRAME would print <signal handler called>,
- which really is not what we want here. */
- "amd64 openbsd trap",
- NORMAL_FRAME,
- default_frame_unwind_stop_reason,
- amd64obsd_trapframe_this_id,
- amd64obsd_trapframe_prev_register,
- NULL,
- amd64obsd_trapframe_sniffer
- };
- static void
- amd64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
- {
- i386_gdbarch_tdep *tdep = (i386_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- amd64_init_abi (info, gdbarch,
- amd64_target_description (X86_XSTATE_SSE_MASK, true));
- obsd_init_abi (info, gdbarch);
- /* Initialize general-purpose register set details. */
- tdep->gregset_reg_offset = amd64obsd_r_reg_offset;
- tdep->gregset_num_regs = ARRAY_SIZE (amd64obsd_r_reg_offset);
- tdep->sizeof_gregset = 24 * 8;
- tdep->jb_pc_offset = 7 * 8;
- tdep->sigtramp_p = amd64obsd_sigtramp_p;
- tdep->sigcontext_addr = amd64obsd_sigcontext_addr;
- tdep->sc_reg_offset = amd64obsd_sc_reg_offset;
- tdep->sc_num_regs = ARRAY_SIZE (amd64obsd_sc_reg_offset);
- /* OpenBSD provides a user-level threads implementation. */
- bsd_uthread_set_supply_uthread (gdbarch, amd64obsd_supply_uthread);
- bsd_uthread_set_collect_uthread (gdbarch, amd64obsd_collect_uthread);
- /* OpenBSD uses SVR4-style shared libraries. */
- set_solib_svr4_fetch_link_map_offsets
- (gdbarch, svr4_lp64_fetch_link_map_offsets);
- /* Unwind kernel trap frames correctly. */
- frame_unwind_prepend_unwinder (gdbarch, &amd64obsd_trapframe_unwind);
- }
- void _initialize_amd64obsd_tdep ();
- void
- _initialize_amd64obsd_tdep ()
- {
- /* The OpenBSD/amd64 native dependent code makes this assumption. */
- gdb_assert (ARRAY_SIZE (amd64obsd_r_reg_offset) == AMD64_NUM_GREGS);
- gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
- GDB_OSABI_OPENBSD, amd64obsd_init_abi);
- }
|