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From: "Ying Huang" <ying.huang@oss.cipunited.com>
To: <elfutils-devel@sourceware.org>
Cc: "Ying Huang" <ying.huang@oss.cipunited.com>
Subject: [PATCH 4/5] stack: Fix stack unwind failure on mips
Date: Tue, 11 Apr 2023 16:12:48 +0800	[thread overview]
Message-ID: <20230411081141.1762395-5-ying.huang@oss.cipunited.com> (raw)
In-Reply-To: <20230411081141.1762395-1-ying.huang@oss.cipunited.com>

[-- Attachment #1: Type: text/plain, Size: 9471 bytes --]

From: Ying Huang <ying.huang@oss.cipunited.com>

add abi_cfi, set_initial_registers_tid, unwind on mips.
"./src/stack -p PID" can show stack information
---
 backends/Makefile.am    |  3 +-
 backends/mips_cfi.c     | 68 +++++++++++++++++++++++++++++++++
 backends/mips_init.c    |  4 ++
 backends/mips_initreg.c | 70 ++++++++++++++++++++++++++++++++++
 backends/mips_unwind.c  | 84 +++++++++++++++++++++++++++++++++++++++++
 5 files changed, 228 insertions(+), 1 deletion(-)
 create mode 100644 backends/mips_cfi.c
 create mode 100644 backends/mips_initreg.c
 create mode 100644 backends/mips_unwind.c

diff --git a/backends/Makefile.am b/backends/Makefile.am
index 428a1a03..ddc31c9d 100644
--- a/backends/Makefile.am
+++ b/backends/Makefile.am
@@ -100,7 +100,8 @@ loongarch_SRCS = loongarch_init.c loongarch_symbol.c
 
 arc_SRCS = arc_init.c arc_symbol.c
 
-mips_SRCS = mips_init.c mips_symbol.c mips_attrs.c
+mips_SRCS = mips_init.c mips_symbol.c mips_attrs.c mips_initreg.c \
+	    mips_cfi.c mips_unwind.c
 
 libebl_backends_a_SOURCES = $(i386_SRCS) $(sh_SRCS) $(x86_64_SRCS) \
 			    $(ia64_SRCS) $(alpha_SRCS) $(arm_SRCS) \
diff --git a/backends/mips_cfi.c b/backends/mips_cfi.c
new file mode 100644
index 00000000..77132cc1
--- /dev/null
+++ b/backends/mips_cfi.c
@@ -0,0 +1,68 @@
+/* MIPS ABI-specified defaults for DWARF CFI.
+   Copyright (C) 2009 Red Hat, Inc.
+   Copyright (C) 2023 CIP United Inc.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * 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
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <dwarf.h>
+
+#define BACKEND mips_
+#include "libebl_CPU.h"
+
+int
+mips_abi_cfi (Ebl *ebl __attribute__ ((unused)), Dwarf_CIE *abi_info)
+{
+  static const uint8_t abi_cfi[] =
+    {
+      DW_CFA_def_cfa, ULEB128_7 (31), ULEB128_7 (0),
+      /* Callee-saved regs.  */
+      DW_CFA_same_value, ULEB128_7 (16), /* s0 */
+      DW_CFA_same_value, ULEB128_7 (17), /* s1 */
+      DW_CFA_same_value, ULEB128_7 (18), /* s2 */
+      DW_CFA_same_value, ULEB128_7 (19), /* s3 */
+      DW_CFA_same_value, ULEB128_7 (20), /* s4 */
+      DW_CFA_same_value, ULEB128_7 (21), /* s5 */
+      DW_CFA_same_value, ULEB128_7 (22), /* s6 */
+      DW_CFA_same_value, ULEB128_7 (23), /* s7 */
+      DW_CFA_same_value, ULEB128_7 (28), /* gp */
+      DW_CFA_same_value, ULEB128_7 (29), /* sp */
+      DW_CFA_same_value, ULEB128_7 (30), /* fp */
+
+      DW_CFA_val_offset, ULEB128_7 (29), ULEB128_7 (0),
+    };
+
+  abi_info->initial_instructions = abi_cfi;
+  abi_info->initial_instructions_end = &abi_cfi[sizeof abi_cfi];
+  abi_info->data_alignment_factor = -4;
+
+  abi_info->return_address_register = 31; /* %ra */
+
+  return 0;
+}
diff --git a/backends/mips_init.c b/backends/mips_init.c
index 4c2f21b9..3caa9fee 100644
--- a/backends/mips_init.c
+++ b/backends/mips_init.c
@@ -55,5 +55,9 @@ mips_init (Elf *elf __attribute__ ((unused)),
   HOOK (eh, check_object_attribute);
   HOOK (eh, check_special_symbol);
   HOOK (eh, check_reloc_target_type);
+  HOOK (eh, set_initial_registers_tid);
+  HOOK (eh, abi_cfi);
+  HOOK (eh, unwind);
+  eh->frame_nregs = 32;
   return eh;
 }
diff --git a/backends/mips_initreg.c b/backends/mips_initreg.c
new file mode 100644
index 00000000..31b8de13
--- /dev/null
+++ b/backends/mips_initreg.c
@@ -0,0 +1,70 @@
+/* Fetch live process registers from TID.
+   Copyright (C) 2023 CIP United Inc.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * 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
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdlib.h>
+#if (defined(mips) || defined(__mips) || defined(__mips__) || defined(MIPS) || defined(__MIPS__)) && defined(__linux__)
+# include <sys/user.h>
+# include <sys/ptrace.h>
+#endif
+
+#define BACKEND mips_
+#include "libebl_CPU.h"
+#include <stdio.h>
+
+
+bool
+mips_set_initial_registers_tid (pid_t tid __attribute__ ((unused)),
+			  ebl_tid_registers_t *setfunc __attribute__ ((unused)),
+				  void *arg __attribute__ ((unused)))
+{
+#if (!defined(mips) && !defined(__mips) && !defined(__mips__) && !defined(MIPS) && !defined(__MIPS__)) || !defined(__linux__)
+  return false;
+#else /* __mips__ */
+/* For PTRACE_GETREGS */
+struct pt_regs {
+    uint64_t regs[32];
+    uint64_t lo;
+    uint64_t hi;
+    uint64_t pc;
+    uint64_t badvaddr;
+    uint64_t cause;
+    uint64_t status;
+};
+
+  struct pt_regs gregs;
+  if (ptrace (PTRACE_GETREGS, tid, 0, &gregs) != 0)
+    return false;
+  if (! setfunc (-1, 1, (Dwarf_Word *) &gregs.pc, arg))
+    return false;
+  return setfunc (0, 32, (Dwarf_Word *) &gregs.regs[0], arg);
+#endif /* __mips__ */
+}
diff --git a/backends/mips_unwind.c b/backends/mips_unwind.c
new file mode 100644
index 00000000..d09db3a9
--- /dev/null
+++ b/backends/mips_unwind.c
@@ -0,0 +1,84 @@
+/* Get previous frame state for an existing frame state.
+   Copyright (C) 2016 The Qt Company Ltd.
+   Copyright (C) 2023 CIP United Inc.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * 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
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#define BACKEND mips_
+#define SP_REG 29
+#define FP_REG 30
+#define LR_REG 31
+#define FP_OFFSET 0
+#define LR_OFFSET 8
+#define SP_OFFSET 16
+
+#include "libebl_CPU.h"
+
+/* There was no CFI. Maybe we happen to have a frame pointer and can unwind from that?  */
+
+bool
+EBLHOOK(unwind) (Ebl *ebl __attribute__ ((unused)), Dwarf_Addr pc __attribute__ ((unused)),
+                 ebl_tid_registers_t *setfunc, ebl_tid_registers_get_t *getfunc,
+                 ebl_pid_memory_read_t *readfunc, void *arg,
+                 bool *signal_framep __attribute__ ((unused)))
+{
+  Dwarf_Word fp, lr, sp;
+
+  if (!getfunc(LR_REG, 1, &lr, arg))
+    return false;
+
+  if (lr == 0 || !setfunc(-1, 1, &lr, arg))
+    return false;
+
+  if (!getfunc(FP_REG, 1, &fp, arg))
+    fp = 0;
+
+  if (!getfunc(SP_REG, 1, &sp, arg))
+    sp = 0;
+
+  Dwarf_Word newLr, newFp, newSp;
+
+  if (!readfunc(fp + LR_OFFSET, &newLr, arg))
+    newLr = 0;
+
+  if (!readfunc(fp + FP_OFFSET, &newFp, arg))
+    newFp = 0;
+
+  newSp = fp + SP_OFFSET;
+
+  // These are not fatal if they don't work. They will just prevent unwinding at the next frame.
+  setfunc(LR_REG, 1, &newLr, arg);
+  setfunc(FP_REG, 1, &newFp, arg);
+  setfunc(SP_REG, 1, &newSp, arg);
+
+  // If the fp is invalid, we might still have a valid lr.
+  // But if the fp is valid, then the stack should be moving in the right direction.
+  return fp == 0 || newSp > sp;
+}
-- 
2.30.2

  parent reply	other threads:[~2023-04-11  8:13 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-11  8:12 [PATCH 0/5] Add support for MIPS Ying Huang
2023-04-11  8:12 ` [PATCH 1/5] strip: Adapt src/strip -o -f on mips Ying Huang
2023-05-09 15:15   ` Mark Wielaard
2023-05-16  6:38     ` Ying Huang
2023-05-21 21:13       ` Mark Wielaard
2023-05-24  6:21         ` Ying Huang
2023-05-16  6:46     ` Ying Huang
2023-05-16  7:34       ` Ying Huang
2023-05-21 21:14         ` Mark Wielaard
2023-05-26  2:48           ` Ying Huang
2023-05-16  8:05     ` [EXTERNAL] " Luke Diamand
2023-04-11  8:12 ` [PATCH 2/5] readelf: Adapt src/readelf -h/-S/-r/-w/-l/-d/-a " Ying Huang
2023-05-11 14:31   ` Mark Wielaard
2023-05-16  8:01     ` Ying Huang
2023-07-24  8:35     ` Ying Huang
2023-07-25  8:15       ` Ying Huang
2023-07-27  6:08         ` Ying Huang
2023-08-01 21:43           ` Mark Wielaard
2023-08-01 13:14         ` Mark Wielaard
2023-08-01  9:25       ` Mark Wielaard
2023-04-11  8:12 ` [PATCH 3/5] elflint: Fix invalid type of relocation info and other issues " Ying Huang
2023-05-11 15:59   ` Mark Wielaard
2023-05-17  9:14     ` Ying Huang
2023-04-11  8:12 ` Ying Huang [this message]
2023-05-11 16:07   ` [PATCH 4/5] stack: Fix stack unwind failure " Mark Wielaard
2023-05-18  6:14     ` Ying Huang
2023-04-11  8:12 ` [PATCH 5/5] backends: Fix run-native-test.sh and run-funcretval++11.sh run fail " Ying Huang
2023-05-11 16:38   ` Mark Wielaard
2023-05-18  9:06     ` Ying Huang
2023-05-04  2:24 ` [PATCH 0/5] Add support for MIPS 黄莺

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