[PUSHED master] arc: Add support for Linux coredump files
Shahab Vahedi
shahab.vahedi@gmail.com
Wed Oct 7 16:11:10 GMT 2020
From: Anton Kolesov <Anton.Kolesov@synopsys.com>
With the implemenations in this patch, ARC gdb can handle
coredump related matters. The binutils counter part of
this patch has already been pushed [1].
v2 [2]:
- arc_linux_collect_gregset: Use "reg <= ARC_LAST_REGNUM" instead of
"reg < ARC_LAST_REGNUM" for the condition check of the for-loop.
- arc-linux-tdep.c: Use "ARC_LAST_REGNUM < ARRAY_SIZE (...)" instead of
"ARC_LAST_REGNUM <= ARRAY_SIZE (...)" for the "asserts".
- Use "buf + arc_linux_core_reg_offsets[ARC_ERET_REGNUM]" instead of
"buf + REG_OFF (6)".
- Fix a few typos/indentation.
v3 [3]:
- Use gdb_assert_not_reached(text) instead of gdb_assert (!text).
- Remove unnecessary braces in the for loop.
[1] arc: Add support for ARC HS extra registers in core files
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=2745674244d6aecddcf636475034bdb9c0a6b4a0
[2] First remarks
https://sourceware.org/pipermail/gdb-patches/2020-September/171912.html
[3] Second remarks
https://sourceware.org/pipermail/gdb-patches/2020-October/172302.html
gdb/ChangeLog:
* arc-linux-tdep.h: New file.
* arc-linux-tdep.c (arc_linux_core_reg_offsets,
arc_linux_supply_gregset, arc_linux_supply_v2_regset,
arc_linux_collect_gregset, arc_linux_collect_v2_regset,
arc_linux_gregset, arc_linux_v2_regset,
arc_linux_iterate_over_regset_sections,
arc_linux_core_read_description): Implement.
(arc_linux_init_osabi): Set iterate_over_regset_sections.
* arc-tdep.h (ARC_OFFSET_NO_REGISTER): Declare.
(arc_gdbarch_features_create): Add.
* arc-tdep.c (arc_gdbarch_features_create): Not static anymore.
---
gdb/arc-linux-tdep.c | 191 +++++++++++++++++++++++++++++++++++++++++++
gdb/arc-linux-tdep.h | 52 ++++++++++++
gdb/arc-tdep.c | 5 +-
gdb/arc-tdep.h | 12 ++-
4 files changed, 256 insertions(+), 4 deletions(-)
create mode 100644 gdb/arc-linux-tdep.h
diff --git a/gdb/arc-linux-tdep.c b/gdb/arc-linux-tdep.c
index 36f32459bbe..9ff5f1214a1 100644
--- a/gdb/arc-linux-tdep.c
+++ b/gdb/arc-linux-tdep.c
@@ -27,7 +27,65 @@
/* ARC header files. */
#include "opcodes/arc-dis.h"
+#include "arc-linux-tdep.h"
#include "arc-tdep.h"
+#include "arch/arc.h"
+
+#define REGOFF(offset) (offset * ARC_REGISTER_SIZE)
+
+/* arc_linux_core_reg_offsets[i] is the offset in the .reg section of GDB
+ regnum i. Array index is an internal GDB register number, as defined in
+ arc-tdep.h:arc_regnum.
+
+ From include/uapi/asm/ptrace.h in the ARC Linux sources. */
+
+/* The layout of this struct is tightly bound to "arc_regnum" enum
+ in arc-tdep.h. Any change of order in there, must be reflected
+ here as well. */
+static const int arc_linux_core_reg_offsets[] = {
+ /* R0 - R12. */
+ REGOFF (22), REGOFF (21), REGOFF (20), REGOFF (19),
+ REGOFF (18), REGOFF (17), REGOFF (16), REGOFF (15),
+ REGOFF (14), REGOFF (13), REGOFF (12), REGOFF (11),
+ REGOFF (10),
+
+ /* R13 - R25. */
+ REGOFF (37), REGOFF (36), REGOFF (35), REGOFF (34),
+ REGOFF (33), REGOFF (32), REGOFF (31), REGOFF (30),
+ REGOFF (29), REGOFF (28), REGOFF (27), REGOFF (26),
+ REGOFF (25),
+
+ REGOFF (9), /* R26 (GP) */
+ REGOFF (8), /* FP */
+ REGOFF (23), /* SP */
+ ARC_OFFSET_NO_REGISTER, /* ILINK */
+ ARC_OFFSET_NO_REGISTER, /* R30 */
+ REGOFF (7), /* BLINK */
+
+ /* R32 - R59. */
+ ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
+ ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
+ ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
+ ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
+ ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
+ ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
+ ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
+ ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
+ ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
+ ARC_OFFSET_NO_REGISTER,
+
+ REGOFF (4), /* LP_COUNT */
+ ARC_OFFSET_NO_REGISTER, /* RESERVED */
+ ARC_OFFSET_NO_REGISTER, /* LIMM */
+ ARC_OFFSET_NO_REGISTER, /* PCL */
+
+ REGOFF (39), /* PC */
+ REGOFF (5), /* STATUS32 */
+ REGOFF (2), /* LP_START */
+ REGOFF (3), /* LP_END */
+ REGOFF (1), /* BTA */
+ REGOFF (6) /* ERET */
+};
/* Implement the "cannot_fetch_register" gdbarch method. */
@@ -227,6 +285,136 @@ arc_linux_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
}
}
+void
+arc_linux_supply_gregset (const struct regset *regset,
+ struct regcache *regcache,
+ int regnum, const void *gregs, size_t size)
+{
+ gdb_static_assert (ARC_LAST_REGNUM
+ < ARRAY_SIZE (arc_linux_core_reg_offsets));
+
+ const bfd_byte *buf = (const bfd_byte *) gregs;
+
+ for (int reg = 0; reg <= ARC_LAST_REGNUM; reg++)
+ if (arc_linux_core_reg_offsets[reg] != ARC_OFFSET_NO_REGISTER)
+ regcache->raw_supply (reg, buf + arc_linux_core_reg_offsets[reg]);
+}
+
+void
+arc_linux_supply_v2_regset (const struct regset *regset,
+ struct regcache *regcache, int regnum,
+ const void *v2_regs, size_t size)
+{
+ const bfd_byte *buf = (const bfd_byte *) v2_regs;
+
+ /* user_regs_arcv2 is defined in linux arch/arc/include/uapi/asm/ptrace.h. */
+ regcache->raw_supply (ARC_R30_REGNUM, buf);
+ regcache->raw_supply (ARC_R58_REGNUM, buf + REGOFF (1));
+ regcache->raw_supply (ARC_R59_REGNUM, buf + REGOFF (2));
+}
+
+/* Populate BUF with register REGNUM from the REGCACHE. */
+
+static void
+collect_register (const struct regcache *regcache, struct gdbarch *gdbarch,
+ int regnum, gdb_byte *buf)
+{
+ /* Skip non-existing registers. */
+ if ((arc_linux_core_reg_offsets[regnum] == ARC_OFFSET_NO_REGISTER))
+ return;
+
+ /* The address where the execution has stopped is in pseudo-register
+ STOP_PC. However, when kernel code is returning from the exception,
+ it uses the value from ERET register. Since, TRAP_S (the breakpoint
+ instruction) commits, the ERET points to the next instruction. In
+ other words: ERET != STOP_PC. To jump back from the kernel code to
+ the correct address, ERET must be overwritten by GDB's STOP_PC. Else,
+ the program will continue at the address after the current instruction.
+ */
+ if (regnum == gdbarch_pc_regnum (gdbarch))
+ regnum = ARC_ERET_REGNUM;
+ regcache->raw_collect (regnum, buf + arc_linux_core_reg_offsets[regnum]);
+}
+
+void
+arc_linux_collect_gregset (const struct regset *regset,
+ const struct regcache *regcache,
+ int regnum, void *gregs, size_t size)
+{
+ gdb_static_assert (ARC_LAST_REGNUM
+ < ARRAY_SIZE (arc_linux_core_reg_offsets));
+
+ gdb_byte *buf = (gdb_byte *) gregs;
+ struct gdbarch *gdbarch = regcache->arch ();
+
+ /* regnum == -1 means writing all the registers. */
+ if (regnum == -1)
+ for (int reg = 0; reg <= ARC_LAST_REGNUM; reg++)
+ collect_register (regcache, gdbarch, reg, buf);
+ else if (regnum <= ARC_LAST_REGNUM)
+ collect_register (regcache, gdbarch, regnum, buf);
+ else
+ gdb_assert_not_reached ("Invalid regnum in arc_linux_collect_gregset.");
+}
+
+void
+arc_linux_collect_v2_regset (const struct regset *regset,
+ const struct regcache *regcache, int regnum,
+ void *v2_regs, size_t size)
+{
+ bfd_byte *buf = (bfd_byte *) v2_regs;
+
+ regcache->raw_collect (ARC_R30_REGNUM, buf);
+ regcache->raw_collect (ARC_R58_REGNUM, buf + REGOFF (1));
+ regcache->raw_collect (ARC_R59_REGNUM, buf + REGOFF (2));
+}
+
+/* Linux regset definitions. */
+
+static const struct regset arc_linux_gregset = {
+ arc_linux_core_reg_offsets,
+ arc_linux_supply_gregset,
+ arc_linux_collect_gregset,
+};
+
+static const struct regset arc_linux_v2_regset = {
+ NULL,
+ arc_linux_supply_v2_regset,
+ arc_linux_collect_v2_regset,
+};
+
+/* Implement the `iterate_over_regset_sections` gdbarch method. */
+
+static void
+arc_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
+ iterate_over_regset_sections_cb *cb,
+ void *cb_data,
+ const struct regcache *regcache)
+{
+ /* There are 40 registers in Linux user_regs_struct, although some of
+ them are now just a mere paddings, kept to maintain binary
+ compatibility with older tools. */
+ const int sizeof_gregset = 40 * ARC_REGISTER_SIZE;
+
+ cb (".reg", sizeof_gregset, sizeof_gregset, &arc_linux_gregset, NULL,
+ cb_data);
+ cb (".reg-arc-v2", ARC_LINUX_SIZEOF_V2_REGSET, ARC_LINUX_SIZEOF_V2_REGSET,
+ &arc_linux_v2_regset, NULL, cb_data);
+}
+
+/* Implement the `core_read_description` gdbarch method. */
+
+static const struct target_desc *
+arc_linux_core_read_description (struct gdbarch *gdbarch,
+ struct target_ops *target,
+ bfd *abfd)
+{
+ arc_arch_features features
+ = arc_arch_features_create (abfd,
+ gdbarch_bfd_arch_info (gdbarch)->mach);
+ return arc_lookup_target_description (features);
+}
+
/* Initialization specific to Linux environment. */
static void
@@ -260,6 +448,9 @@ arc_linux_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
set_gdbarch_software_single_step (gdbarch, arc_linux_software_single_step);
set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
set_gdbarch_skip_solib_resolver (gdbarch, arc_linux_skip_solib_resolver);
+ set_gdbarch_iterate_over_regset_sections
+ (gdbarch, arc_linux_iterate_over_regset_sections);
+ set_gdbarch_core_read_description (gdbarch, arc_linux_core_read_description);
/* GNU/Linux uses SVR4-style shared libraries, with 32-bit ints, longs
and pointers (ILP32). */
diff --git a/gdb/arc-linux-tdep.h b/gdb/arc-linux-tdep.h
new file mode 100644
index 00000000000..c26cacd7029
--- /dev/null
+++ b/gdb/arc-linux-tdep.h
@@ -0,0 +1,52 @@
+/* Target dependent code for GNU/Linux ARC.
+
+ Copyright 2020 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/>. */
+
+#ifndef ARC_LINUX_TDEP_H
+#define ARC_LINUX_TDEP_H
+
+#include "gdbarch.h"
+#include "regset.h"
+
+#define ARC_LINUX_SIZEOF_V2_REGSET (3 * ARC_REGISTER_SIZE)
+
+/* Reads registers from the NT_PRSTATUS data array into the regcache. */
+
+void arc_linux_supply_gregset (const struct regset *regset,
+ struct regcache *regcache, int regnum,
+ const void *gregs, size_t size);
+
+/* Reads regsiters from the NT_ARC_V2 data array into the regcache. */
+
+void arc_linux_supply_v2_regset (const struct regset *regset,
+ struct regcache *regcache, int regnum,
+ const void *v2_regs, size_t size);
+
+/* Writes registers from the regcache into the NT_PRSTATUS data array. */
+
+void arc_linux_collect_gregset (const struct regset *regset,
+ const struct regcache *regcache,
+ int regnum, void *gregs, size_t size);
+
+/* Writes registers from the regcache into the NT_ARC_V2 data array. */
+
+void arc_linux_collect_v2_regset (const struct regset *regset,
+ const struct regcache *regcache,
+ int regnum, void *v2_regs, size_t size);
+
+#endif /* ARC_LINUX_TDEP_H */
diff --git a/gdb/arc-tdep.c b/gdb/arc-tdep.c
index 60c76af3352..c29a16eccf6 100644
--- a/gdb/arc-tdep.c
+++ b/gdb/arc-tdep.c
@@ -1883,10 +1883,9 @@ mach_type_to_arc_isa (const unsigned long mach)
}
}
-/* Common construction code for ARC_ARCH_FEATURES struct. If there
- is no ABFD, then a FEATURE with default values is returned. */
+/* See arc-tdep.h. */
-static arc_arch_features
+arc_arch_features
arc_arch_features_create (const bfd *abfd, const unsigned long mach)
{
/* Use 4 as a fallback value. */
diff --git a/gdb/arc-tdep.h b/gdb/arc-tdep.h
index 6331d29f402..09fcbeab9c7 100644
--- a/gdb/arc-tdep.h
+++ b/gdb/arc-tdep.h
@@ -85,7 +85,9 @@ enum arc_regnum
ARC_LP_END_REGNUM,
/* Branch target address. */
ARC_BTA_REGNUM,
- ARC_LAST_AUX_REGNUM = ARC_BTA_REGNUM,
+ /* Exception return address. */
+ ARC_ERET_REGNUM,
+ ARC_LAST_AUX_REGNUM = ARC_ERET_REGNUM,
ARC_LAST_REGNUM = ARC_LAST_AUX_REGNUM,
/* Additional ABI constants. */
@@ -105,6 +107,9 @@ enum arc_regnum
/* STATUS32 register: current instruction is a delay slot. */
#define ARC_STATUS32_DE_MASK (1 << 6)
+/* Special value for register offset arrays. */
+#define ARC_OFFSET_NO_REGISTER (-1)
+
#define arc_print(fmt, args...) fprintf_unfiltered (gdb_stdlog, fmt, ##args)
extern int arc_debug;
@@ -182,4 +187,9 @@ CORE_ADDR arc_insn_get_branch_target (const struct arc_instruction &insn);
CORE_ADDR arc_insn_get_linear_next_pc (const struct arc_instruction &insn);
+/* Create an arc_arch_features instance from the provided data. */
+
+arc_arch_features arc_arch_features_create (const bfd *abfd,
+ const unsigned long mach);
+
#endif /* ARC_TDEP_H */
--
2.28.0
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