Wednesday, September 30, 2020

gdb powerpc64 support

This adds basic powerpc64 support to the ports gdb. Only really
implements target support, so this can only really look at core dumps.
But it does a better job than base gdb.

Since the ports tree is still locked, I may actually work on improving
this a bit. But at least people have the diff if they need it.

Index: devel/gdb/patches/patch-gdb_config_powerpc_obsd64_mh
===================================================================
RCS file: devel/gdb/patches/patch-gdb_config_powerpc_obsd64_mh
diff -N devel/gdb/patches/patch-gdb_config_powerpc_obsd64_mh
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ devel/gdb/patches/patch-gdb_config_powerpc_obsd64_mh 30 Sep 2020 20:18:56 -0000
@@ -0,0 +1,10 @@
+$OpenBSD$
+
+Index: gdb/config/powerpc/obsd64.mh
+--- gdb/config/powerpc/obsd64.mh.orig
++++ gdb/config/powerpc/obsd64.mh
+@@ -0,0 +1,4 @@
++# Host: OpenBSD/powerpc
++NATDEPFILES= fork-child.o inf-ptrace.o obsd-nat.o ppc64obsd-nat.o bsd-kvm.o
++
++LOADLIBES= -lkvm
Index: devel/gdb/patches/patch-gdb_configure_host
===================================================================
RCS file: /cvs/ports/devel/gdb/patches/patch-gdb_configure_host,v
retrieving revision 1.1
diff -u -p -r1.1 patch-gdb_configure_host
--- devel/gdb/patches/patch-gdb_configure_host 10 Jul 2018 11:03:46 -0000 1.1
+++ devel/gdb/patches/patch-gdb_configure_host 30 Sep 2020 20:18:56 -0000
@@ -1,6 +1,7 @@
$OpenBSD: patch-gdb_configure_host,v 1.1 2018/07/10 11:03:46 kettenis Exp $
---- gdb/configure.host.orig Sat Jan 21 05:48:42 2017
-+++ gdb/configure.host Tue Mar 7 23:52:43 2017
+Index: gdb/configure.host
+--- gdb/configure.host.orig
++++ gdb/configure.host
@@ -82,6 +82,7 @@ case "${host}" in
*-*-darwin*) gdb_host=darwin ;;

@@ -9,3 +10,11 @@ $OpenBSD: patch-gdb_configure_host,v 1.1

alpha*-*-linux*) gdb_host=alpha-linux ;;
alpha*-*-freebsd* | alpha*-*-kfreebsd*-gnu)
+@@ -137,6 +138,7 @@ powerpc*-*-freebsd*) gdb_host=fbsd ;;
+ powerpc-*-netbsd* | powerpc-*-knetbsd*-gnu)
+ gdb_host=nbsd ;;
+ powerpc-*-openbsd*) gdb_host=obsd ;;
++powerpc64-*-openbsd*) gdb_host=obsd64 ;;
+
+ powerpc64*-*-linux*) gdb_host=ppc64-linux
+ # Support 'pseudo-native' debugging on the Cell BE
Index: devel/gdb/patches/patch-gdb_configure_tgt
===================================================================
RCS file: /cvs/ports/devel/gdb/patches/patch-gdb_configure_tgt,v
retrieving revision 1.1
diff -u -p -r1.1 patch-gdb_configure_tgt
--- devel/gdb/patches/patch-gdb_configure_tgt 10 Jul 2018 11:03:46 -0000 1.1
+++ devel/gdb/patches/patch-gdb_configure_tgt 30 Sep 2020 20:18:56 -0000
@@ -16,3 +16,16 @@ Index: gdb/configure.tgt
alpha*-*-linux*)
# Target: Little-endian Alpha running Linux
gdb_target_obs="alpha-tdep.o alpha-mdebug-tdep.o alpha-linux-tdep.o \
+@@ -428,6 +435,12 @@ powerpc-*-openbsd*)
+ # Target: OpenBSD/powerpc
+ gdb_target_obs="rs6000-tdep.o ppc-sysv-tdep.o ppcobsd-tdep.o \
+ solib-svr4.o \
++ ravenscar-thread.o ppc-ravenscar-thread.o"
++ ;;
++powerpc64-*-openbsd*)
++ # Target: OpenBSD/powerpc64
++ gdb_target_obs="rs6000-tdep.o ppc-sysv-tdep.o ppc64-tdep.o \
++ ppc64obsd-tdep.o obsd-tdep.o solib-svr4.o \
+ ravenscar-thread.o ppc-ravenscar-thread.o"
+ ;;
+ powerpc-*-aix* | rs6000-*-* | powerpc64-*-aix*)
Index: devel/gdb/patches/patch-gdb_ppc64obsd-nat_c
===================================================================
RCS file: devel/gdb/patches/patch-gdb_ppc64obsd-nat_c
diff -N devel/gdb/patches/patch-gdb_ppc64obsd-nat_c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ devel/gdb/patches/patch-gdb_ppc64obsd-nat_c 30 Sep 2020 20:18:56 -0000
@@ -0,0 +1,7 @@
+$OpenBSD$
+
+Index: gdb/ppc64obsd-nat.c
+--- gdb/ppc64obsd-nat.c.orig
++++ gdb/ppc64obsd-nat.c
+@@ -0,0 +1 @@
++/* Empty */
Index: devel/gdb/patches/patch-gdb_ppc64obsd-tdep_c
===================================================================
RCS file: devel/gdb/patches/patch-gdb_ppc64obsd-tdep_c
diff -N devel/gdb/patches/patch-gdb_ppc64obsd-tdep_c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ devel/gdb/patches/patch-gdb_ppc64obsd-tdep_c 30 Sep 2020 20:18:56 -0000
@@ -0,0 +1,441 @@
+$OpenBSD$
+
+Index: gdb/ppc64obsd-tdep.c
+--- gdb/ppc64obsd-tdep.c.orig
++++ gdb/ppc64obsd-tdep.c
+@@ -0,0 +1,435 @@
++/* Target-dependent code for OpenBSD/powerpc64.
++
++ Copyright (C) 2004, 2005, 2006 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 2 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, write to the Free Software
++ Foundation, Inc., 51 Franklin Street, Fifth Floor,
++ Boston, MA 02110-1301, USA. */
++
++#include "defs.h"
++#include "arch-utils.h"
++#include "floatformat.h"
++#include "frame.h"
++#include "frame-unwind.h"
++#include "osabi.h"
++#include "regcache.h"
++#include "regset.h"
++#include "symtab.h"
++#include "trad-frame.h"
++
++#include "obsd-tdep.h"
++#include "ppc-tdep.h"
++#include "ppc64obsd-tdep.h"
++#include "solib-svr4.h"
++
++/* Register offsets from <machine/reg.h>. */
++struct ppc_reg_offsets ppc64obsd_reg_offsets;
++struct ppc_reg_offsets ppc64obsd_fpreg_offsets;
++
++
++/* Register set support functions. */
++
++static void
++ppc64_supply_reg (struct regcache *regcache, int regnum,
++ const gdb_byte *regs, size_t offset)
++{
++ if (regnum != -1 && offset != -1)
++ regcache_raw_supply (regcache, regnum, regs + offset);
++}
++
++static void
++ppc64_collect_reg (const struct regcache *regcache, int regnum,
++ gdb_byte *regs, size_t offset)
++{
++ if (regnum != -1 && offset != -1)
++ regcache_raw_collect (regcache, regnum, regs + offset);
++}
++
++/* Supply register REGNUM in the general-purpose register set REGSET
++ from the buffer specified by GREGS and LEN to register cache
++ REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
++
++void
++ppc64_supply_gregset (const struct regset *regset, struct regcache *regcache,
++ int regnum, const void *gregs, size_t len)
++{
++ struct gdbarch *gdbarch = get_regcache_arch (regcache);
++ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
++ const struct ppc_reg_offsets *offsets
++ = (const struct ppc_reg_offsets *) regset->regmap;
++ size_t offset;
++ int i;
++
++ for (i = tdep->ppc_gp0_regnum, offset = offsets->r0_offset;
++ i < tdep->ppc_gp0_regnum + ppc_num_gprs;
++ i++, offset += 8)
++ {
++ if (regnum == -1 || regnum == i)
++ ppc64_supply_reg (regcache, i, (const gdb_byte *) gregs, offset);
++ }
++
++ if (regnum == -1 || regnum == gdbarch_pc_regnum (gdbarch))
++ ppc64_supply_reg (regcache, gdbarch_pc_regnum (gdbarch),
++ (const gdb_byte *) gregs, offsets->pc_offset);
++ if (regnum == -1 || regnum == tdep->ppc_ps_regnum)
++ ppc64_supply_reg (regcache, tdep->ppc_ps_regnum,
++ (const gdb_byte *) gregs, offsets->ps_offset);
++ if (regnum == -1 || regnum == tdep->ppc_cr_regnum)
++ ppc64_supply_reg (regcache, tdep->ppc_cr_regnum,
++ (const gdb_byte *) gregs, offsets->cr_offset);
++ if (regnum == -1 || regnum == tdep->ppc_lr_regnum)
++ ppc64_supply_reg (regcache, tdep->ppc_lr_regnum,
++ (const gdb_byte *) gregs, offsets->lr_offset);
++ if (regnum == -1 || regnum == tdep->ppc_ctr_regnum)
++ ppc64_supply_reg (regcache, tdep->ppc_ctr_regnum,
++ (const gdb_byte *) gregs, offsets->ctr_offset);
++ if (regnum == -1 || regnum == tdep->ppc_xer_regnum)
++ ppc64_supply_reg (regcache, tdep->ppc_xer_regnum,
++ (const gdb_byte *) gregs, offsets->cr_offset);
++}
++
++/* Collect register REGNUM in the general-purpose register set
++ REGSET. from register cache REGCACHE into the buffer specified by
++ GREGS and LEN. If REGNUM is -1, do this for all registers in
++ REGSET. */
++
++void
++ppc64_collect_gregset (const struct regset *regset,
++ const struct regcache *regcache,
++ int regnum, void *gregs, size_t len)
++{
++ struct gdbarch *gdbarch = get_regcache_arch (regcache);
++ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
++ const struct ppc_reg_offsets *offsets
++ = (const struct ppc_reg_offsets *) regset->regmap;
++ size_t offset;
++ int i;
++
++ offset = offsets->r0_offset;
++ for (i = tdep->ppc_gp0_regnum;
++ i < tdep->ppc_gp0_regnum + ppc_num_gprs;
++ i++, offset += 8)
++ {
++ if (regnum == -1 || regnum == i)
++ ppc64_collect_reg (regcache, i, (gdb_byte *) gregs, offset);
++ }
++
++ if (regnum == -1 || regnum == gdbarch_pc_regnum (gdbarch))
++ ppc64_collect_reg (regcache, gdbarch_pc_regnum (gdbarch),
++ (gdb_byte *) gregs, offsets->pc_offset);
++ if (regnum == -1 || regnum == tdep->ppc_ps_regnum)
++ ppc64_collect_reg (regcache, tdep->ppc_ps_regnum,
++ (gdb_byte *) gregs, offsets->ps_offset);
++ if (regnum == -1 || regnum == tdep->ppc_cr_regnum)
++ ppc64_collect_reg (regcache, tdep->ppc_cr_regnum,
++ (gdb_byte *) gregs, offsets->cr_offset);
++ if (regnum == -1 || regnum == tdep->ppc_lr_regnum)
++ ppc64_collect_reg (regcache, tdep->ppc_lr_regnum,
++ (gdb_byte *) gregs, offsets->lr_offset);
++ if (regnum == -1 || regnum == tdep->ppc_ctr_regnum)
++ ppc64_collect_reg (regcache, tdep->ppc_ctr_regnum,
++ (gdb_byte *) gregs, offsets->ctr_offset);
++ if (regnum == -1 || regnum == tdep->ppc_xer_regnum)
++ ppc64_collect_reg (regcache, tdep->ppc_xer_regnum,
++ (gdb_byte *) gregs, offsets->xer_offset);
++}
++
++/* Core file support. */
++
++/* Supply register REGNUM in the general-purpose register set REGSET
++ from the buffer specified by GREGS and LEN to register cache
++ REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
++
++void
++ppc64obsd_supply_gregset (const struct regset *regset,
++ struct regcache *regcache, int regnum,
++ const void *gregs, size_t len)
++{
++ ppc64_supply_gregset (regset, regcache, regnum, gregs, len);
++}
++
++/* Collect register REGNUM in the general-purpose register set
++ REGSET. from register cache REGCACHE into the buffer specified by
++ GREGS and LEN. If REGNUM is -1, do this for all registers in
++ REGSET. */
++
++void
++ppc64obsd_collect_gregset (const struct regset *regset,
++ const struct regcache *regcache, int regnum,
++ void *gregs, size_t len)
++{
++ ppc64_collect_gregset (regset, regcache, regnum, gregs, len);
++}
++
++/* OpenBSD/powerpc register set. */
++
++struct regset ppc64obsd_gregset =
++{
++ &ppc64obsd_reg_offsets,
++ ppc64obsd_supply_gregset
++};
++
++struct regset ppc64obsd_fpregset =
++{
++ &ppc64obsd_fpreg_offsets,
++ ppc_supply_fpregset
++};
++
++/* Iterate over core file register note sections. */
++
++static void
++ppc64obsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
++ iterate_over_regset_sections_cb *cb,
++ void *cb_data,
++ const struct regcache *regcache)
++{
++ cb (".reg", 304, &ppc64obsd_gregset, NULL, cb_data);
++ // cb (".reg2", 1048, &ppc64obsd_fpregset, NULL, cb_data);
++}
++
++
++/* Signal trampolines. */
++
++/* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page
++ in virtual memory. The randomness makes it somewhat tricky to
++ detect it, but fortunately we can rely on the fact that the start
++ of the sigtramp routine is page-aligned. We recognize the
++ trampoline by looking for the code that invokes the sigreturn
++ system call. The offset where we can find that code varies from
++ release to release.
++
++ By the way, the mapping mentioned above is read-only, so you cannot
++ place a breakpoint in the signal trampoline. */
++
++/* Default page size. */
++static const int ppc64obsd_page_size = 4096;
++
++/* Offset for sigreturn(2). */
++static const int ppc64obsd_sigreturn_offset[] = {
++ 0x98, /* OpenBSD 3.8 */
++ 0x0c, /* OpenBSD 3.2 */
++ -1
++};
++
++static int
++ppc64obsd_sigtramp_frame_sniffer (const struct frame_unwind *self,
++ 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);
++ CORE_ADDR pc = get_frame_pc (this_frame);
++ CORE_ADDR start_pc = (pc & ~(ppc64obsd_page_size - 1));
++ const int *offset;
++ const char *name;
++
++ find_pc_partial_function (pc, &name, NULL, NULL);
++ if (name)
++ return 0;
++
++ for (offset = ppc64obsd_sigreturn_offset; *offset != -1; offset++)
++ {
++ gdb_byte buf[2 * PPC_INSN_SIZE];
++ unsigned long insn;
++
++ if (!safe_frame_unwind_memory (this_frame, start_pc + *offset,
++ buf, sizeof buf))
++ continue;
++
++ /* Check for "li r0,SYS_sigreturn". */
++ insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
++ if (insn != 0x38000067)
++ continue;
++
++ /* Check for "sc". */
++ insn = extract_unsigned_integer (buf + PPC_INSN_SIZE,
++ PPC_INSN_SIZE, byte_order);
++ if (insn != 0x44000002)
++ continue;
++
++ return 1;
++ }
++
++ return 0;
++}
++
++static struct trad_frame_cache *
++ppc64obsd_sigtramp_frame_cache (struct frame_info *this_frame,
++ void **this_cache)
++{
++ struct gdbarch *gdbarch = get_frame_arch (this_frame);
++ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
++ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
++ struct trad_frame_cache *cache;
++ CORE_ADDR addr, base, func;
++ gdb_byte buf[PPC_INSN_SIZE];
++ unsigned long insn, sigcontext_offset;
++ 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_pc (this_frame);
++ func &= ~(ppc64obsd_page_size - 1);
++ if (!safe_frame_unwind_memory (this_frame, func, buf, sizeof buf))
++ return cache;
++
++ /* Calculate the offset where we can find `struct sigcontext'. We
++ base our calculation on the amount of stack space reserved by the
++ first instruction of the signal trampoline. */
++ insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
++ sigcontext_offset = (0x10000 - (insn & 0x0000ffff)) + 8;
++
++ base = get_frame_register_unsigned (this_frame, gdbarch_sp_regnum (gdbarch));
++ addr = base + sigcontext_offset + 2 * tdep->wordsize;
++ for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
++ {
++ int regnum = i + tdep->ppc_gp0_regnum;
++ trad_frame_set_reg_addr (cache, regnum, addr);
++ }
++ trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
++ addr += tdep->wordsize;
++ trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
++ addr += tdep->wordsize;
++ trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
++ addr += tdep->wordsize;
++ trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
++ addr += tdep->wordsize;
++ trad_frame_set_reg_addr (cache, gdbarch_pc_regnum (gdbarch), addr);
++ /* SRR0? */
++ addr += tdep->wordsize;
++
++ /* Construct the frame ID using the function start. */
++ trad_frame_set_id (cache, frame_id_build (base, func));
++
++ return cache;
++}
++
++static void
++ppc64obsd_sigtramp_frame_this_id (struct frame_info *this_frame,
++ void **this_cache, struct frame_id *this_id)
++{
++ struct trad_frame_cache *cache =
++ ppc64obsd_sigtramp_frame_cache (this_frame, this_cache);
++
++ trad_frame_get_id (cache, this_id);
++}
++
++static struct value *
++ppc64obsd_sigtramp_frame_prev_register (struct frame_info *this_frame,
++ void **this_cache, int regnum)
++{
++ struct trad_frame_cache *cache =
++ ppc64obsd_sigtramp_frame_cache (this_frame, this_cache);
++
++ return trad_frame_get_register (cache, this_frame, regnum);
++}
++
++static const struct frame_unwind ppc64obsd_sigtramp_frame_unwind = {
++ SIGTRAMP_FRAME,
++ default_frame_unwind_stop_reason,
++ ppc64obsd_sigtramp_frame_this_id,
++ ppc64obsd_sigtramp_frame_prev_register,
++ NULL,
++ ppc64obsd_sigtramp_frame_sniffer
++};
++
++
++static void
++ppc64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
++{
++ obsd_init_abi (info, gdbarch);
++
++ /* OpenBSD doesn't support the 128-bit `long double' from the psABI. */
++ set_gdbarch_long_double_bit (gdbarch, 64);
++ set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
++
++ /* OpenBSD uses SVR4-style shared libraries. */
++ set_solib_svr4_fetch_link_map_offsets
++ (gdbarch, svr4_lp64_fetch_link_map_offsets);
++
++ set_gdbarch_iterate_over_regset_sections
++ (gdbarch, ppc64obsd_iterate_over_regset_sections);
++
++ frame_unwind_append_unwinder (gdbarch, &ppc64obsd_sigtramp_frame_unwind);
++}
++
++
++/* OpenBSD uses uses the traditional NetBSD core file format, even for
++ ports that use ELF. */
++#define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF
++
++static enum gdb_osabi
++ppc64obsd_core_osabi_sniffer (bfd *abfd)
++{
++ if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
++ return GDB_OSABI_NETBSD_CORE;
++
++ return GDB_OSABI_UNKNOWN;
++}
++
++
++/* Provide a prototype to silence -Wmissing-prototypes. */
++void _initialize_ppc64obsd_tdep (void);
++
++void
++_initialize_ppc64obsd_tdep (void)
++{
++ /* BFD doesn't set a flavour for NetBSD style a.out core files. */
++ gdbarch_register_osabi_sniffer (bfd_arch_powerpc, bfd_target_unknown_flavour,
++ ppc64obsd_core_osabi_sniffer);
++
++#if 0
++ gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_OPENBSD_ELF,
++ ppc64obsd_init_abi);
++

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