Files
binutils-gdb/gdb/i386-netbsd-tdep.c
Simon Marchi a2e3cce344 gdb/solib: C++ify solib_ops
Convert solib_ops into an abstract base class (with abstract methods,
some of them with default implementations) and convert all the existing
solib_ops instances to solib_ops derived classes / implementations.

Prior to this patch, solib_ops is a structure holding function pointers,
of which there are only a handful of global instances (in the
`solib-*.c` files).  When passing an `solib_ops *` around, it's a
pointer to one of these instances.  After this patch, there are no more
global solib_ops instances.  Instances are created as needed and stored
in struct program_space.  These instances could eventually be made to
contain the program space-specific data, which is currently kept in
per-program space registries (I have some pending patches for that).

Prior to this patch, `gdbarch_so_ops` is a gdbarch method that returns a
pointer to the appropriate solib_ops implementation for the gdbarch.
This is replaced with the `gdbarch_make_solib_ops` method, which returns
a new instance of the appropriate solib_ops implementation for this
gdbarch.  This requires introducing some factory functions for the
various solib_ops implementation, to be used as `gdbarch_make_solib_ops`
callbacks.  For instance:

    solib_ops_up
    make_linux_ilp32_svr4_solib_ops ()
    {
      return std::make_unique<linux_ilp32_svr4_solib_ops> ();
    }

The previous code is full of cases of tdep files copying some base
solib_ops implementation, and overriding one or more function pointer
(see ppc_linux_init_abi, for instance).  I tried to convert all of this
is a class hierarchy.  I like that it's now possible to get a good
static view of all the existing solib_ops variants.  The hierarchy looks
like this:

    solib_ops
    ├── aix_solib_ops
    ├── darwin_solib_ops
    ├── dsbt_solib_ops
    ├── frv_solib_ops
    ├── rocm_solib_ops
    ├── svr4_solib_ops
    │   ├── ilp32_svr4_solib_ops
    │   ├── lp64_svr4_solib_ops
    │   ├── linux_ilp32_svr4_solib_ops
    │   │   ├── mips_linux_ilp32_svr4_solib_ops
    │   │   └── ppc_linux_ilp32_svr4_solib_ops
    │   ├── linux_lp64_svr4_solib_ops
    │   │   └── mips_linux_lp64_svr4_solib_ops
    │   ├── mips_nbsd_ilp32_svr4_solib_ops
    │   ├── mips_nbsd_lp64_svr4_solib_ops
    │   ├── mips_fbsd_ilp32_svr4_solib_ops
    │   └── mips_fbsd_lp64_svr4_solib_ops
    └── target_solib_ops
        └── windows_solib_ops

The solib-svr4 code has per-arch specialization to provide a
link_map_offsets, containing the offsets of the interesting fields in
`struct link_map` on that particular architecture.  Prior to this patch,
arches would set a callback returning the appropriate link_map_offsets
by calling `set_solib_svr4_fetch_link_map_offsets`, which also happened
to set the gdbarch's so_ops to `&svr_so_ops`.  I converted this to an
abstract virtual method of `struct svr4_solib_ops`, meaning that all
classes deriving from svr4_solib_ops must provide a method returning the
appropriate link_map_offsets for the architecture.  I renamed
`set_solib_svr4_fetch_link_map_offsets` to `set_solib_svr4_ops`.  This
function is still necessary because it also calls
set_gdbarch_iterate_over_objfiles_in_search_order, but if it was not for
that, we could get rid of it.

There is an instance of CRTP in mips-linux-tdep.c, because both
mips_linux_ilp32_svr4_solib_ops and mips_linux_lp64_svr4_solib_ops need
to derive from different SVR4 base classes (linux_ilp32_svr4_solib_ops
and linux_lp64_svr4_solib_ops), but they both want to override the
in_dynsym_resolve_code method with the same implementation.

The solib_ops::supports_namespaces method is new: the support for
namespaces was previously predicated by the presence or absence of a
find_solib_ns method.  It now needs to be explicit.

There is a new progspace::release_solib_ops method, which is only needed
for rocm_solib_ops.  For the moment, rocm_solib_ops replaces and wraps
the existing svr4_solib_ops instance, in order to combine the results of
the two.  The plan is to have a subsequent patch to allow program spaces to have
multiple solib_ops, removing the need for release_solib_ops.

Speaking of rocm_solib_ops: it previously overrode only a few methods by
copying svr4_solib_ops and overwriting some function pointers.  Now, it
needs to implement all the methods that svr4_solib_ops implements, in
order to forward the call.  Otherwise, the default solib_ops method
would be called, hiding the svr4_solib_ops implementation.  Again, this
can be removed once we have support for multiple solib_ops in a
program_space.

There is also a small change in how rocm_solib_ops is activated.  Prior
to this patch, it's done at the end of rocm_update_solib_list.  Since it
overrides the function pointer in the static svr4_solib_ops, and then
overwrites the host gdbarch, so_ops field, it's something that happens
only once.  After the patch though, we need to set rocm_solib_ops in all
the program spaces that appear.  We do this in
rocm_solib_target_inferior_created and in the new
rocm_solib_target_inferior_execd.  After this, I will explore doing a
change where rocm_solib_ops is only set when we detect the ROCm runtime
is loaded.

Change-Id: I5896b5bcbf8bdb024d67980380feba1ffefaa4c9
Approved-By: Pedro Alves <pedro@palves.net>
2025-06-26 14:08:31 -04:00

429 lines
11 KiB
C
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* Target-dependent code for NetBSD/i386.
Copyright (C) 1988-2025 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 "arch-utils.h"
#include "frame.h"
#include "gdbcore.h"
#include "regcache.h"
#include "regset.h"
#include "osabi.h"
#include "symtab.h"
#include "trad-frame.h"
#include "tramp-frame.h"
#include "i386-tdep.h"
#include "i387-tdep.h"
#include "netbsd-tdep.h"
#include "solib-svr4.h"
/* From <machine/reg.h>. */
static int i386nbsd_r_reg_offset[] =
{
0 * 4, /* %eax */
1 * 4, /* %ecx */
2 * 4, /* %edx */
3 * 4, /* %ebx */
4 * 4, /* %esp */
5 * 4, /* %ebp */
6 * 4, /* %esi */
7 * 4, /* %edi */
8 * 4, /* %eip */
9 * 4, /* %eflags */
10 * 4, /* %cs */
11 * 4, /* %ss */
12 * 4, /* %ds */
13 * 4, /* %es */
14 * 4, /* %fs */
15 * 4 /* %gs */
};
/* From <machine/signal.h>. */
static int i386nbsd_sc_reg_offset[] =
{
10 * 4, /* %eax */
9 * 4, /* %ecx */
8 * 4, /* %edx */
7 * 4, /* %ebx */
14 * 4, /* %esp */
6 * 4, /* %ebp */
5 * 4, /* %esi */
4 * 4, /* %edi */
11 * 4, /* %eip */
13 * 4, /* %eflags */
12 * 4, /* %cs */
15 * 4, /* %ss */
3 * 4, /* %ds */
2 * 4, /* %es */
1 * 4, /* %fs */
0 * 4 /* %gs */
};
/* From <machine/mcontext.h>. */
static int i386nbsd_mc_reg_offset[] =
{
11 * 4, /* %eax */
10 * 4, /* %ecx */
9 * 4, /* %edx */
8 * 4, /* %ebx */
7 * 4, /* %esp */
6 * 4, /* %ebp */
5 * 4, /* %esi */
4 * 4, /* %edi */
14 * 4, /* %eip */
16 * 4, /* %eflags */
15 * 4, /* %cs */
18 * 4, /* %ss */
3 * 4, /* %ds */
2 * 4, /* %es */
1 * 4, /* %fs */
0 * 4 /* %gs */
};
static void i386nbsd_sigtramp_cache_init (const struct tramp_frame *,
const frame_info_ptr &,
struct trad_frame_cache *,
CORE_ADDR);
static const struct tramp_frame i386nbsd_sigtramp_sc16 =
{
SIGTRAMP_FRAME,
1,
{
/* leal 0x10(%esp), %eax */
{ 0x8d, ULONGEST_MAX },
{ 0x44, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x10, ULONGEST_MAX },
/* pushl %eax */
{ 0x50, ULONGEST_MAX },
/* pushl %eax */
{ 0x50, ULONGEST_MAX },
/* movl $0x127, %eax # __sigreturn14 */
{ 0xb8, ULONGEST_MAX },
{ 0x27, ULONGEST_MAX },
{0x01, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
/* int $0x80 */
{ 0xcd, ULONGEST_MAX },
{ 0x80, ULONGEST_MAX},
/* movl $0x1, %eax # exit */
{ 0xb8, ULONGEST_MAX },
{ 0x01, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
/* int $0x80 */
{ 0xcd, ULONGEST_MAX },
{ 0x80, ULONGEST_MAX},
{ TRAMP_SENTINEL_INSN, ULONGEST_MAX }
},
i386nbsd_sigtramp_cache_init
};
static const struct tramp_frame i386nbsd_sigtramp_sc2 =
{
SIGTRAMP_FRAME,
1,
{
/* leal 0x0c(%esp), %eax */
{ 0x8d, ULONGEST_MAX },
{ 0x44, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x0c, ULONGEST_MAX },
/* movl %eax, 0x4(%esp) */
{ 0x89, ULONGEST_MAX },
{ 0x44, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x04, ULONGEST_MAX },
/* movl $0x127, %eax # __sigreturn14 */
{ 0xb8, ULONGEST_MAX },
{ 0x27, ULONGEST_MAX },
{0x01, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
/* int $0x80 */
{ 0xcd, ULONGEST_MAX },
{ 0x80, ULONGEST_MAX},
/* movl %eax, 0x4(%esp) */
{ 0x89, ULONGEST_MAX },
{ 0x44, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x04, ULONGEST_MAX },
/* movl $0x1, %eax */
{ 0xb8, ULONGEST_MAX },
{ 0x01, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
/* int $0x80 */
{ 0xcd, ULONGEST_MAX },
{ 0x80, ULONGEST_MAX},
{ TRAMP_SENTINEL_INSN, ULONGEST_MAX }
},
i386nbsd_sigtramp_cache_init
};
static const struct tramp_frame i386nbsd_sigtramp_si2 =
{
SIGTRAMP_FRAME,
1,
{
/* movl 8(%esp),%eax */
{ 0x8b, ULONGEST_MAX },
{ 0x44, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x08, ULONGEST_MAX },
/* movl %eax, 0x4(%esp) */
{ 0x89, ULONGEST_MAX },
{ 0x44, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x04, ULONGEST_MAX },
/* movl $0x134, %eax # setcontext */
{ 0xb8, ULONGEST_MAX },
{ 0x34, ULONGEST_MAX },
{ 0x01, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
/* int $0x80 */
{ 0xcd, ULONGEST_MAX },
{ 0x80, ULONGEST_MAX },
/* movl %eax, 0x4(%esp) */
{ 0x89, ULONGEST_MAX },
{ 0x44, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x04, ULONGEST_MAX },
/* movl $0x1, %eax */
{ 0xb8, ULONGEST_MAX },
{ 0x01, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
/* int $0x80 */
{ 0xcd, ULONGEST_MAX },
{ 0x80, ULONGEST_MAX },
{ TRAMP_SENTINEL_INSN, ULONGEST_MAX }
},
i386nbsd_sigtramp_cache_init
};
static const struct tramp_frame i386nbsd_sigtramp_si31 =
{
SIGTRAMP_FRAME,
1,
{
/* leal 0x8c(%esp), %eax */
{ 0x8d, ULONGEST_MAX },
{ 0x84, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x8c, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
/* movl %eax, 0x4(%esp) */
{ 0x89, ULONGEST_MAX },
{ 0x44, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x04, ULONGEST_MAX },
/* movl $0x134, %eax # setcontext */
{ 0xb8, ULONGEST_MAX },
{ 0x34, ULONGEST_MAX },
{ 0x01, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
/* int $0x80 */
{ 0xcd, ULONGEST_MAX },
{ 0x80, ULONGEST_MAX},
/* movl %eax, 0x4(%esp) */
{ 0x89, ULONGEST_MAX },
{ 0x44, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x04, ULONGEST_MAX },
/* movl $0x1, %eax */
{ 0xb8, ULONGEST_MAX },
{ 0x01, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
/* int $0x80 */
{ 0xcd, ULONGEST_MAX },
{ 0x80, ULONGEST_MAX},
{ TRAMP_SENTINEL_INSN, ULONGEST_MAX }
},
i386nbsd_sigtramp_cache_init
};
static const struct tramp_frame i386nbsd_sigtramp_si4 =
{
SIGTRAMP_FRAME,
1,
{
/* leal 0x8c(%esp), %eax */
{ 0x8d, ULONGEST_MAX },
{ 0x84, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x8c, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
/* movl %eax, 0x4(%esp) */
{ 0x89, ULONGEST_MAX },
{ 0x44, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x04, ULONGEST_MAX },
/* movl $0x134, %eax # setcontext */
{ 0xb8, ULONGEST_MAX },
{ 0x34, ULONGEST_MAX },
{ 0x01, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
{ 0x00, ULONGEST_MAX },
/* int $0x80 */
{ 0xcd, ULONGEST_MAX },
{ 0x80, ULONGEST_MAX},
/* movl $0xffffffff,0x4(%esp) */
{ 0xc7, ULONGEST_MAX },
{ 0x44, ULONGEST_MAX },
{ 0x24, ULONGEST_MAX },
{ 0x04, ULONGEST_MAX },
{ 0xff, ULONGEST_MAX },
{ 0xff, ULONGEST_MAX },
{ 0xff, ULONGEST_MAX },
{ 0xff, ULONGEST_MAX },
/* movl $0x1, %eax */
{ 0xb8, ULONGEST_MAX },
{ 0x01, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
{0x00, ULONGEST_MAX },
/* int $0x80 */
{ 0xcd, ULONGEST_MAX },
{ 0x80, ULONGEST_MAX},
{ TRAMP_SENTINEL_INSN, ULONGEST_MAX }
},
i386nbsd_sigtramp_cache_init
};
static void
i386nbsd_sigtramp_cache_init (const struct tramp_frame *self,
const frame_info_ptr &this_frame,
struct trad_frame_cache *this_cache,
CORE_ADDR func)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
CORE_ADDR sp = get_frame_register_unsigned (this_frame, I386_ESP_REGNUM);
CORE_ADDR base;
int *reg_offset;
int num_regs;
int i;
if (self == &i386nbsd_sigtramp_sc16 || self == &i386nbsd_sigtramp_sc2)
{
reg_offset = i386nbsd_sc_reg_offset;
num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset);
/* Read in the sigcontext address. */
base = read_memory_unsigned_integer (sp + 8, 4, byte_order);
}
else
{
reg_offset = i386nbsd_mc_reg_offset;
num_regs = ARRAY_SIZE (i386nbsd_mc_reg_offset);
/* Read in the ucontext address. */
base = read_memory_unsigned_integer (sp + 8, 4, byte_order);
/* offsetof(ucontext_t, uc_mcontext) == 36 */
base += 36;
}
for (i = 0; i < num_regs; i++)
if (reg_offset[i] != -1)
trad_frame_set_reg_addr (this_cache, i, base + reg_offset[i]);
/* Construct the frame ID using the function start. */
trad_frame_set_id (this_cache, frame_id_build (sp, func));
}
static void
i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
/* Obviously NetBSD is BSD-based. */
i386bsd_init_abi (info, gdbarch);
nbsd_init_abi (info, gdbarch);
/* NetBSD has a different `struct reg'. */
tdep->gregset_reg_offset = i386nbsd_r_reg_offset;
tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset);
tdep->sizeof_gregset = 16 * 4;
/* NetBSD uses -freg-struct-return by default. */
tdep->struct_return = reg_struct_return;
/* NetBSD uses tramp_frame sniffers for signal trampolines. */
tdep->sigcontext_addr= 0;
tdep->sigtramp_start = 0;
tdep->sigtramp_end = 0;
tdep->sigtramp_p = 0;
tdep->sc_reg_offset = 0;
tdep->sc_num_regs = 0;
tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc16);
tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_sc2);
tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si2);
tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si31);
tramp_frame_prepend_unwinder (gdbarch, &i386nbsd_sigtramp_si4);
}
/* NetBSD ELF. */
static void
i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
/* It's still NetBSD. */
i386nbsd_init_abi (info, gdbarch);
/* But ELF-based. */
i386_elf_init_abi (info, gdbarch);
/* NetBSD ELF uses SVR4-style shared libraries. */
set_solib_svr4_ops (gdbarch, make_svr4_ilp32_solib_ops);
/* NetBSD ELF uses -fpcc-struct-return by default. */
tdep->struct_return = pcc_struct_return;
}
INIT_GDB_FILE (i386nbsd_tdep)
{
gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD,
i386nbsdelf_init_abi);
}