| From 32b366249fd42d74cbc4a91039431554ebadcfd0 Mon Sep 17 00:00:00 2001 |
| From: Anton Kolesov <anton.kolesov@synopsys.com> |
| Date: Fri, 14 Feb 2014 11:56:23 +0400 |
| Subject: [PATCH 4/4] gdb: Add native support for ARC in GNU/Linux |
| |
| With this patch in place it is possible to build a GDB that |
| can run on ARC (GNU/Linux) hosts for debugging ARC targets. |
| |
| The "arc-linux-nat.c" is a rather small one that mostly deals |
| with registers and a few thread related hooks. |
| |
| v2 [1]: |
| - Remove "void" from the input of "_initialize_arc_linux_nat ()" |
| |
| [1] Tom's remark after the first patch |
| https://sourceware.org/pipermail/gdb-patches/2020-November/173223.html |
| |
| gdb/ChangeLog: |
| |
| * Makefile.in (ALLDEPFILES): Add arc-linux-nat.c. |
| * configure.host (host to gdb names): Add arc*-*-linux*. |
| * configure.nat (gdb_host_cpu): Add arc. |
| * arc-linux-nat.c: New. |
| |
| Upstream-Status: Backport [https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=04c9f85efcd8df5fc482ce97c0104cc7dd5d19e6] |
| |
| Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com> |
| Signed-off-by: Shahab Vahedi <shahab@synopsys.com> |
| Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> |
| --- |
| gdb/Makefile.in | 1 + |
| gdb/arc-linux-nat.c | 320 ++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| gdb/configure.host | 3 + |
| gdb/configure.nat | 4 + |
| 4 files changed, 328 insertions(+) |
| create mode 100644 gdb/arc-linux-nat.c |
| |
| diff --git a/gdb/Makefile.in b/gdb/Makefile.in |
| index ec371fc7e52..c76136907ae 100644 |
| --- a/gdb/Makefile.in |
| +++ b/gdb/Makefile.in |
| @@ -2136,6 +2136,7 @@ ALLDEPFILES = \ |
| amd64-obsd-tdep.c \ |
| amd64-sol2-tdep.c \ |
| amd64-tdep.c \ |
| + arc-linux-nat.c \ |
| arc-tdep.c \ |
| arm.c \ |
| arm-bsd-tdep.c \ |
| diff --git a/gdb/arc-linux-nat.c b/gdb/arc-linux-nat.c |
| new file mode 100644 |
| index 00000000000..41301fd4fed |
| --- /dev/null |
| +++ b/gdb/arc-linux-nat.c |
| @@ -0,0 +1,320 @@ |
| +/* Native-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/>. */ |
| + |
| +#include "defs.h" |
| +#include "frame.h" |
| +#include "inferior.h" |
| +#include "gdbcore.h" |
| +#include "regcache.h" |
| +#include "gdbsupport/gdb_assert.h" |
| +#include "target.h" |
| +#include "linux-nat.h" |
| +#include "nat/gdb_ptrace.h" |
| + |
| +#include <stdint.h> |
| +#include <sys/types.h> |
| +#include <sys/param.h> |
| +#include <signal.h> |
| +#include <sys/user.h> |
| +#include <sys/ioctl.h> |
| +#include "gdbsupport/gdb_wait.h" |
| +#include <fcntl.h> |
| +#include <sys/procfs.h> |
| +#include <linux/elf.h> |
| + |
| +#include "gregset.h" |
| +#include "arc-tdep.h" |
| +#include "arc-linux-tdep.h" |
| +#include "arch/arc.h" |
| + |
| +/* Defines ps_err_e, struct ps_prochandle. */ |
| +#include "gdb_proc_service.h" |
| + |
| +/* Linux starting with 4.12 supports NT_ARC_V2 note type, which adds R30, |
| + R58 and R59 registers, which are specific to ARC HS and aren't |
| + available in ARC 700. */ |
| +#if defined (NT_ARC_V2) && defined (__ARCHS__) |
| +#define ARC_HAS_V2_REGSET |
| +#endif |
| + |
| +class arc_linux_nat_target final : public linux_nat_target |
| +{ |
| +public: |
| + /* Add ARC register access methods. */ |
| + void fetch_registers (struct regcache *, int) override; |
| + void store_registers (struct regcache *, int) override; |
| + |
| + const struct target_desc *read_description () override; |
| + |
| + /* Handle threads */ |
| + void low_prepare_to_resume (struct lwp_info *lp) override; |
| +}; |
| + |
| +static arc_linux_nat_target the_arc_linux_nat_target; |
| + |
| +/* Read general registers from target process/thread (via ptrace) |
| + into REGCACHE. */ |
| + |
| +static void |
| +fetch_gregs (struct regcache *regcache, int regnum) |
| +{ |
| + const int tid = get_ptrace_pid (regcache->ptid ()); |
| + struct iovec iov; |
| + gdb_gregset_t regs; |
| + |
| + iov.iov_base = ®s; |
| + iov.iov_len = sizeof (gdb_gregset_t); |
| + |
| + if (ptrace (PTRACE_GETREGSET, tid, NT_PRSTATUS, (void *) &iov) < 0) |
| + perror_with_name (_("Couldn't get general registers")); |
| + else |
| + arc_linux_supply_gregset (NULL, regcache, regnum, ®s, 0); |
| +} |
| + |
| +#ifdef ARC_HAS_V2_REGSET |
| +/* Read ARC v2 registers from target process/thread (via ptrace) |
| + into REGCACHE. */ |
| + |
| +static void |
| +fetch_v2_regs (struct regcache *regcache, int regnum) |
| +{ |
| + const int tid = get_ptrace_pid (regcache->ptid ()); |
| + struct iovec iov; |
| + bfd_byte v2_buffer[ARC_LINUX_SIZEOF_V2_REGSET]; |
| + |
| + iov.iov_base = &v2_buffer; |
| + iov.iov_len = ARC_LINUX_SIZEOF_V2_REGSET; |
| + |
| + if (ptrace (PTRACE_GETREGSET, tid, NT_ARC_V2, (void *) &iov) < 0) |
| + perror_with_name (_("Couldn't get ARC HS registers")); |
| + else |
| + arc_linux_supply_v2_regset (NULL, regcache, regnum, v2_buffer, 0); |
| +} |
| +#endif |
| + |
| +/* Store general registers from REGCACHE into the target process/thread. */ |
| + |
| +static void |
| +store_gregs (const struct regcache *regcache, int regnum) |
| +{ |
| + const int tid = get_ptrace_pid (regcache->ptid ()); |
| + struct iovec iov; |
| + gdb_gregset_t regs; |
| + |
| + iov.iov_base = ®s; |
| + iov.iov_len = sizeof (gdb_gregset_t); |
| + |
| + if (ptrace (PTRACE_GETREGSET, tid, NT_PRSTATUS, (void *) &iov) < 0) |
| + perror_with_name (_("Couldn't get general registers")); |
| + else |
| + { |
| + arc_linux_collect_gregset (NULL, regcache, regnum, regs, 0); |
| + |
| + if (ptrace (PTRACE_SETREGSET, tid, NT_PRSTATUS, (void *) &iov) < 0) |
| + perror_with_name (_("Couldn't write general registers")); |
| + } |
| +} |
| + |
| +#ifdef ARC_HAS_V2_REGSET |
| +/* Store ARC v2 registers from REGCACHE into the target process/thread. */ |
| + |
| +static void |
| +store_v2_regs (const struct regcache *regcache, int regnum) |
| +{ |
| + const int tid = get_ptrace_pid (regcache->ptid ()); |
| + struct iovec iov; |
| + bfd_byte v2_buffer[ARC_LINUX_SIZEOF_V2_REGSET]; |
| + |
| + iov.iov_base = &v2_buffer; |
| + iov.iov_len = ARC_LINUX_SIZEOF_V2_REGSET; |
| + |
| + if (ptrace (PTRACE_GETREGSET, tid, NT_ARC_V2, (void *) &iov) < 0) |
| + perror_with_name (_("Couldn't get ARC HS registers")); |
| + else |
| + { |
| + arc_linux_collect_v2_regset (NULL, regcache, regnum, v2_buffer, 0); |
| + |
| + if (ptrace (PTRACE_SETREGSET, tid, NT_ARC_V2, (void *) &iov) < 0) |
| + perror_with_name (_("Couldn't write ARC HS registers")); |
| + } |
| +} |
| +#endif |
| + |
| +/* Target operation: Read REGNUM register (all registers if REGNUM == -1) |
| + from target process into REGCACHE. */ |
| + |
| +void |
| +arc_linux_nat_target::fetch_registers (struct regcache *regcache, int regnum) |
| +{ |
| + |
| + if (regnum == -1 || regnum <= ARC_LAST_REGNUM) |
| + fetch_gregs (regcache, regnum); |
| + |
| +#ifdef ARC_HAS_V2_REGSET |
| + if (regnum == -1 |
| + || regnum == ARC_R30_REGNUM |
| + || regnum == ARC_R58_REGNUM |
| + || regnum == ARC_R59_REGNUM) |
| + fetch_v2_regs (regcache, regnum); |
| +#endif |
| +} |
| + |
| +/* Target operation: Store REGNUM register (all registers if REGNUM == -1) |
| + to the target process from REGCACHE. */ |
| + |
| +void |
| +arc_linux_nat_target::store_registers (struct regcache *regcache, int regnum) |
| +{ |
| + if (regnum == -1 || regnum <= ARC_LAST_REGNUM) |
| + store_gregs (regcache, regnum); |
| + |
| +#ifdef ARC_HAS_V2_REGSET |
| + if (regnum == -1 |
| + || regnum == ARC_R30_REGNUM |
| + || regnum == ARC_R58_REGNUM |
| + || regnum == ARC_R59_REGNUM) |
| + store_v2_regs (regcache, regnum); |
| +#endif |
| +} |
| + |
| +/* Copy general purpose register(s) from REGCACHE into regset GREGS. |
| + This function is exported to proc-service.c */ |
| + |
| +void |
| +fill_gregset (const struct regcache *regcache, |
| + gdb_gregset_t *gregs, int regnum) |
| +{ |
| + arc_linux_collect_gregset (NULL, regcache, regnum, gregs, 0); |
| +} |
| + |
| +/* Copy all the general purpose registers from regset GREGS into REGCACHE. |
| + This function is exported to proc-service.c. */ |
| + |
| +void |
| +supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregs) |
| +{ |
| + arc_linux_supply_gregset (NULL, regcache, -1, gregs, 0); |
| +} |
| + |
| +/* ARC doesn't have separate FP registers. This function is exported |
| + to proc-service.c. */ |
| + |
| +void |
| +fill_fpregset (const struct regcache *regcache, |
| + gdb_fpregset_t *fpregsetp, int regnum) |
| +{ |
| + if (arc_debug) |
| + debug_printf ("arc-linux-nat: fill_fpregset called."); |
| + return; |
| +} |
| + |
| +/* ARC doesn't have separate FP registers. This function is exported |
| + to proc-service.c. */ |
| + |
| +void |
| +supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregsetp) |
| +{ |
| + if (arc_debug) |
| + debug_printf ("arc-linux-nat: supply_fpregset called."); |
| + return; |
| +} |
| + |
| +/* Implement the "read_description" method of linux_nat_target. */ |
| + |
| +const struct target_desc * |
| +arc_linux_nat_target::read_description () |
| +{ |
| + /* This is a native target, hence description is hardcoded. */ |
| +#ifdef __ARCHS__ |
| + arc_arch_features features (4, ARC_ISA_ARCV2); |
| +#else |
| + arc_arch_features features (4, ARC_ISA_ARCV1); |
| +#endif |
| + return arc_lookup_target_description (features); |
| +} |
| + |
| +/* As described in arc_linux_collect_gregset(), we need to write resume-PC |
| + to ERET. However by default GDB for native targets doesn't write |
| + registers if they haven't been changed. This is a callback called by |
| + generic GDB, and in this callback we have to rewrite PC value so it |
| + would force rewrite of register on target. It seems that the only |
| + other arch that utilizes this hook is x86/x86-64 for HW breakpoint |
| + support. But then, AFAIK no other arch has this stop_pc/eret |
| + complexity. |
| + |
| + No better way was found, other than this fake write of register value, |
| + to force GDB into writing register to target. Is there any? */ |
| + |
| +void |
| +arc_linux_nat_target::low_prepare_to_resume (struct lwp_info *lwp) |
| +{ |
| + /* When new processes and threads are created we do not have the address |
| + space for them and calling get_thread_regcache will cause an internal |
| + error in GDB. It looks like that checking for last_resume_kind is the |
| + sensible way to determine processes for which we cannot get regcache. |
| + Ultimately, a better way would be removing the need for |
| + low_prepare_to_resume in the first place. */ |
| + if (lwp->last_resume_kind == resume_stop) |
| + return; |
| + |
| + struct regcache *regcache = get_thread_regcache (this, lwp->ptid); |
| + struct gdbarch *gdbarch = regcache->arch (); |
| + |
| + /* Read current PC value, then write it back. It is required to call |
| + invalidate(), otherwise GDB will note that new value is equal to old |
| + value and will skip write. */ |
| + ULONGEST new_pc; |
| + regcache_cooked_read_unsigned (regcache, gdbarch_pc_regnum (gdbarch), |
| + &new_pc); |
| + regcache->invalidate (gdbarch_pc_regnum (gdbarch)); |
| + regcache_cooked_write_unsigned (regcache, gdbarch_pc_regnum (gdbarch), |
| + new_pc); |
| +} |
| + |
| +/* Fetch the thread-local storage pointer for libthread_db. Note that |
| + this function is not called from GDB, but is called from libthread_db. |
| + This is required to debug multithreaded applications with NPTL. */ |
| + |
| +ps_err_e |
| +ps_get_thread_area (struct ps_prochandle *ph, lwpid_t lwpid, int idx, |
| + void **base) |
| +{ |
| + if (arc_debug >= 2) |
| + debug_printf ("arc-linux-nat: ps_get_thread_area called"); |
| + |
| + if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0) |
| + return PS_ERR; |
| + |
| + /* IDX is the bias from the thread pointer to the beginning of the |
| + thread descriptor. It has to be subtracted due to implementation |
| + quirks in libthread_db. */ |
| + *base = (void *) ((char *) *base - idx); |
| + |
| + return PS_OK; |
| +} |
| + |
| +/* Suppress warning from -Wmissing-prototypes. */ |
| +void _initialize_arc_linux_nat (); |
| +void |
| +_initialize_arc_linux_nat () |
| +{ |
| + /* Register the target. */ |
| + linux_target = &the_arc_linux_nat_target; |
| + add_inf_child_target (&the_arc_linux_nat_target); |
| +} |
| diff --git a/gdb/configure.host b/gdb/configure.host |
| index ce528237291..e94a19b0332 100644 |
| --- a/gdb/configure.host |
| +++ b/gdb/configure.host |
| @@ -60,6 +60,7 @@ case "${host_cpu}" in |
| |
| aarch64*) gdb_host_cpu=aarch64 ;; |
| alpha*) gdb_host_cpu=alpha ;; |
| +arc*) gdb_host_cpu=arc ;; |
| arm*) gdb_host_cpu=arm ;; |
| hppa*) gdb_host_cpu=pa ;; |
| i[34567]86*) gdb_host_cpu=i386 ;; |
| @@ -91,6 +92,8 @@ alpha*-*-netbsd* | alpha*-*-knetbsd*-gnu) |
| gdb_host=nbsd ;; |
| alpha*-*-openbsd*) gdb_host=nbsd ;; |
| |
| +arc*-*-linux*) gdb_host=linux ;; |
| + |
| arm*-*-freebsd*) gdb_host=fbsd ;; |
| arm*-*-linux*) gdb_host=linux ;; |
| arm*-*-netbsdelf* | arm*-*-knetbsd*-gnu) |
| diff --git a/gdb/configure.nat b/gdb/configure.nat |
| index bb70e303384..cd11bc86dca 100644 |
| --- a/gdb/configure.nat |
| +++ b/gdb/configure.nat |
| @@ -238,6 +238,10 @@ case ${gdb_host} in |
| nat/aarch64-linux.o \ |
| nat/aarch64-sve-linux-ptrace.o" |
| ;; |
| + arc) |
| + # Host: ARC based machine running GNU/Linux |
| + NATDEPFILES="${NATDEPFILES} arc-linux-nat.o" |
| + ;; |
| arm) |
| # Host: ARM based machine running GNU/Linux |
| NATDEPFILES="${NATDEPFILES} arm-linux-nat.o \ |
| -- |
| 2.16.2 |
| |