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Update to gdb-13.2 - tests wanted
On Thu, 07 Nov 2024 17:50:05 +0100
Pascal Stumpf <pascal@stumpf.co> wrote:
> Thank you for picking this up. I will be testing on arm64, powerpc, arm
> and hppa.
On powerpc, I need to remove patch-bfd_coff-rs6000_c; this obsolete
patch broke the build by adding #include "bfd_stdint.h", but the .h
doesn't exist. After removing the patch, I installed gdb-13.2 and it
works with my simple SIGSEGV example.
On Thu, 7 Nov 2024 17:28:50 +0100
Jeremie Courreges-Anglas <jca@wxcvbn.org> wrote:
> There's a good chance that the blind fixes I have added for arm64 and
> powerpc64 are not enough.
C++ exceptions are broken on powerpc64, and this caused gdb to crash
often in libc++abi. I edited libc++abi in my powerpc64, but didn't
share my diff; I might have the only OpenBSD/powerpc64 with working
C++ exceptions. If someone wants the diff, mail me.
To build gdb-13.2, I needed to remove patch-bfd_coff-rs6000_c and
edit patch-gdb_ppc64-obsd-tdep_c; I have attached my edited patch.
Now gdb-13.2 builds on powerpc64 and begins to run but does nothing
useful, as it can neither load core dumps ("Core file format not
supported") nor run programs ("Don't know how to run."). I will try
to add the missing features in the next few days.
--gkoehler
Index: gdb/ppc64-obsd-tdep.c
--- gdb/ppc64-obsd-tdep.c.orig
+++ gdb/ppc64-obsd-tdep.c
@@ -0,0 +1,411 @@
+/* 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 "gdbarch.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 "ppc64-obsd-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 (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 (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. */
+
+static void
+ppc64_supply_gregset (const struct regset *regset, struct regcache *regcache,
+ int regnum, const void *gregs, size_t len)
+{
+ struct gdbarch *gdbarch = regcache->arch ();
+ ppc_gdbarch_tdep *tdep = gdbarch_tdep<ppc_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. */
+
+static void
+ppc64_collect_gregset (const struct regset *regset,
+ const struct regcache *regcache,
+ int regnum, void *gregs, size_t len)
+{
+ struct gdbarch *gdbarch = regcache->arch ();
+ ppc_gdbarch_tdep *tdep = gdbarch_tdep<ppc_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, 304, &ppc64obsd_gregset, NULL, cb_data);
+ cb (".reg2", 1056, 1056, &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[] = {
+ 0x10, /* OpenBSD 6.8 */
+ -1
+};
+
+static int
+ppc64obsd_sigtramp_frame_sniffer (const struct frame_unwind *self,
+ frame_info_ptr 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))
+ 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 (frame_info_ptr this_frame,
+ void **this_cache)
+{
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ ppc_gdbarch_tdep *tdep = gdbarch_tdep<ppc_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))
+ 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 (frame_info_ptr 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 (frame_info_ptr 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 = {
+ "ppc64 openbsd sigtramp",
+ 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);
+}
+␌
+
+/* Provide a prototype to silence -Wmissing-prototypes. */
+void _initialize_ppc64obsd_tdep (void);
+
+void
+_initialize_ppc64obsd_tdep (void)
+{
+ gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_OPENBSD,
+ ppc64obsd_init_abi);
+ gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc64,
+ GDB_OSABI_OPENBSD, ppc64obsd_init_abi);
+
+ /* Avoid initializing the register offsets again if they were
+ already initailized by ppc64obsd-nat.c. */
+ if (ppc64obsd_reg_offsets.pc_offset == 0)
+ {
+ /* General-purpose registers. */
+ ppc64obsd_reg_offsets.r0_offset = 0;
+ ppc64obsd_reg_offsets.pc_offset = 288;
+ ppc64obsd_reg_offsets.ps_offset = 296;
+ ppc64obsd_reg_offsets.cr_offset = 264;
+ ppc64obsd_reg_offsets.lr_offset = 256;
+ ppc64obsd_reg_offsets.ctr_offset = 280;
+ ppc64obsd_reg_offsets.xer_offset = 272;
+ ppc64obsd_reg_offsets.mq_offset = -1;
+
+ /* Floating-point registers. */
+ ppc64obsd_reg_offsets.f0_offset = -1;
+ ppc64obsd_reg_offsets.fpscr_offset = -1;
+ }
+
+ if (ppc64obsd_fpreg_offsets.fpscr_offset == 0)
+ {
+ /* Floating-point registers. */
+ ppc64obsd_fpreg_offsets.f0_offset = -1;
+ ppc64obsd_fpreg_offsets.fpscr_offset = -1;
+ ppc64obsd_fpreg_offsets.fpscr_size = 8;
+ }
+}
Update to gdb-13.2 - tests wanted