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Date: Fri, 18 Jan 2013 17:55:05 +0530
From: Vineet Gupta <Vineet.Gupta1@...opsys.com>
To: <linux-arch@...r.kernel.org>, <linux-kernel@...r.kernel.org>
CC: <arnd@...db.de>, Vineet Gupta <Vineet.Gupta1@...opsys.com>
Subject: [PATCH v2 51/76] ARC: DWARF2 .debug_frame based stack unwinder
-Originally contributed by Rajeshwar Range <rajeshwar.ranga>
-Derived off of generic unwinder in 2.6.19 and adapted to ARC
Signed-off-by: Vineet Gupta <vgupta@...opsys.com>
Cc: Rajeshwar Range <rajeshwar.ranga>
---
arch/arc/Kconfig | 15 +
arch/arc/include/asm/module.h | 7 +
arch/arc/include/asm/unwind.h | 163 +++++
arch/arc/kernel/Makefile | 6 +
arch/arc/kernel/entry.S | 9 +
arch/arc/kernel/module.c | 42 ++
arch/arc/kernel/setup.c | 3 +
arch/arc/kernel/unwind.c | 1329 +++++++++++++++++++++++++++++++++++++++++
arch/arc/kernel/vmlinux.lds.S | 23 +-
9 files changed, 1596 insertions(+), 1 deletions(-)
create mode 100644 arch/arc/include/asm/unwind.h
create mode 100644 arch/arc/kernel/unwind.c
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index c8a7c09..cd99825 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -25,6 +25,7 @@ config ARC
select GENERIC_SMP_IDLE_THREAD
select HAVE_ARCH_TRACEHOOK
select HAVE_GENERIC_HARDIRQS
+ select HAVE_MOD_ARCH_SPECIFIC if ARC_DW2_UNWIND
select HAVE_OPROFILE
select HOTPLUG if !INITRAMFS_SOURCE=""
select IRQ_DOMAIN
@@ -349,6 +350,20 @@ menuconfig ARC_DBG
bool "ARC debugging"
default y
+config ARC_DW2_UNWIND
+ bool "Enable DWARF specific kernel stack unwind"
+ depends on ARC_DBG
+ default y
+ select KALLSYMS
+ help
+ Compiles the kernel with DWARF unwind information and can be used
+ to get stack backtraces.
+
+ If you say Y here the resulting kernel image will be slightly larger
+ but not slower, and it will give very useful debugging information.
+ If you don't debug the kernel, you can say N, but we may not be able
+ to solve problems without frame unwind information
+
config ARC_DBG_TLB_PARANOIA
bool "Paranoia Checks in Low Level TLB Handlers"
depends on ARC_DBG && !SMP
diff --git a/arch/arc/include/asm/module.h b/arch/arc/include/asm/module.h
index 234b435..518222b 100644
--- a/arch/arc/include/asm/module.h
+++ b/arch/arc/include/asm/module.h
@@ -14,6 +14,13 @@
#include <asm-generic/module.h>
+#ifdef CONFIG_ARC_DW2_UNWIND
+struct mod_arch_specific {
+ void *unw_info;
+ int unw_sec_idx;
+};
+#endif
+
#define MODULE_PROC_FAMILY "ARC700"
#define MODULE_ARCH_VERMAGIC MODULE_PROC_FAMILY
diff --git a/arch/arc/include/asm/unwind.h b/arch/arc/include/asm/unwind.h
new file mode 100644
index 0000000..7ca628b
--- /dev/null
+++ b/arch/arc/include/asm/unwind.h
@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _ASM_ARC_UNWIND_H
+#define _ASM_ARC_UNWIND_H
+
+#ifdef CONFIG_ARC_DW2_UNWIND
+
+#include <linux/sched.h>
+
+struct arc700_regs {
+ unsigned long r0;
+ unsigned long r1;
+ unsigned long r2;
+ unsigned long r3;
+ unsigned long r4;
+ unsigned long r5;
+ unsigned long r6;
+ unsigned long r7;
+ unsigned long r8;
+ unsigned long r9;
+ unsigned long r10;
+ unsigned long r11;
+ unsigned long r12;
+ unsigned long r13;
+ unsigned long r14;
+ unsigned long r15;
+ unsigned long r16;
+ unsigned long r17;
+ unsigned long r18;
+ unsigned long r19;
+ unsigned long r20;
+ unsigned long r21;
+ unsigned long r22;
+ unsigned long r23;
+ unsigned long r24;
+ unsigned long r25;
+ unsigned long r26;
+ unsigned long r27; /* fp */
+ unsigned long r28; /* sp */
+ unsigned long r29;
+ unsigned long r30;
+ unsigned long r31; /* blink */
+ unsigned long r63; /* pc */
+};
+
+struct unwind_frame_info {
+ struct arc700_regs regs;
+ struct task_struct *task;
+ unsigned call_frame:1;
+};
+
+#define UNW_PC(frame) ((frame)->regs.r63)
+#define UNW_SP(frame) ((frame)->regs.r28)
+#define UNW_BLINK(frame) ((frame)->regs.r31)
+
+/* Rajesh FIXME */
+#ifdef CONFIG_FRAME_POINTER
+#define UNW_FP(frame) ((frame)->regs.r27)
+#define FRAME_RETADDR_OFFSET 4
+#define FRAME_LINK_OFFSET 0
+#define STACK_BOTTOM_UNW(tsk) STACK_LIMIT((tsk)->thread.ksp)
+#define STACK_TOP_UNW(tsk) ((tsk)->thread.ksp)
+#else
+#define UNW_FP(frame) ((void)(frame), 0)
+#endif
+
+#define STACK_LIMIT(ptr) (((ptr) - 1) & ~(THREAD_SIZE - 1))
+
+#define UNW_REGISTER_INFO \
+ PTREGS_INFO(r0), \
+ PTREGS_INFO(r1), \
+ PTREGS_INFO(r2), \
+ PTREGS_INFO(r3), \
+ PTREGS_INFO(r4), \
+ PTREGS_INFO(r5), \
+ PTREGS_INFO(r6), \
+ PTREGS_INFO(r7), \
+ PTREGS_INFO(r8), \
+ PTREGS_INFO(r9), \
+ PTREGS_INFO(r10), \
+ PTREGS_INFO(r11), \
+ PTREGS_INFO(r12), \
+ PTREGS_INFO(r13), \
+ PTREGS_INFO(r14), \
+ PTREGS_INFO(r15), \
+ PTREGS_INFO(r16), \
+ PTREGS_INFO(r17), \
+ PTREGS_INFO(r18), \
+ PTREGS_INFO(r19), \
+ PTREGS_INFO(r20), \
+ PTREGS_INFO(r21), \
+ PTREGS_INFO(r22), \
+ PTREGS_INFO(r23), \
+ PTREGS_INFO(r24), \
+ PTREGS_INFO(r25), \
+ PTREGS_INFO(r26), \
+ PTREGS_INFO(r27), \
+ PTREGS_INFO(r28), \
+ PTREGS_INFO(r29), \
+ PTREGS_INFO(r30), \
+ PTREGS_INFO(r31), \
+ PTREGS_INFO(r63)
+
+#define UNW_DEFAULT_RA(raItem, dataAlign) \
+ ((raItem).where == Memory && !((raItem).value * (dataAlign) + 4))
+
+extern int arc_unwind(struct unwind_frame_info *frame);
+extern void arc_unwind_init(void);
+extern void arc_unwind_setup(void);
+extern void *unwind_add_table(struct module *module, const void *table_start,
+ unsigned long table_size);
+extern void unwind_remove_table(void *handle, int init_only);
+
+static inline int
+arch_unwind_init_running(struct unwind_frame_info *info,
+ int (*callback) (struct unwind_frame_info *info,
+ void *arg),
+ void *arg)
+{
+ return 0;
+}
+
+static inline int arch_unw_user_mode(const struct unwind_frame_info *info)
+{
+ return 0;
+}
+
+static inline void arch_unw_init_blocked(struct unwind_frame_info *info)
+{
+ return;
+}
+
+static inline void arch_unw_init_frame_info(struct unwind_frame_info *info,
+ struct pt_regs *regs)
+{
+ return;
+}
+
+#else
+
+#define UNW_PC(frame) ((void)(frame), 0)
+#define UNW_SP(frame) ((void)(frame), 0)
+#define UNW_FP(frame) ((void)(frame), 0)
+
+static inline void arc_unwind_init(void)
+{
+}
+
+static inline void arc_unwind_setup(void)
+{
+}
+#define unwind_add_table(a, b, c)
+#define unwind_remove_table(a, b)
+
+#endif /* CONFIG_ARC_DW2_UNWIND */
+
+#endif /* _ASM_ARC_UNWIND_H */
diff --git a/arch/arc/kernel/Makefile b/arch/arc/kernel/Makefile
index 65915dd..30a5f7e 100644
--- a/arch/arc/kernel/Makefile
+++ b/arch/arc/kernel/Makefile
@@ -14,10 +14,16 @@ obj-y := arcksyms.o setup.o irq.o time.o reset.o ptrace.o entry.o process.o \
obj-$(CONFIG_OF) += devtree.o
obj-$(CONFIG_MODULES) += arcksyms.o module.o
obj-$(CONFIG_SMP) += smp.o
+obj-$(CONFIG_ARC_DW2_UNWIND) += unwind.o
obj-$(CONFIG_ARC_FPU_SAVE_RESTORE) += fpu.o
CFLAGS_fpu.o += -mdpfp
+ifdef CONFIG_ARC_DW2_UNWIND
+CFLAGS_ctx_sw.o += -fno-omit-frame-pointer
+obj-y += ctx_sw.o
+else
obj-y += ctx_sw_asm.o
+endif
extra-y := vmlinux.lds head.o
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index c7b6002..7e392d4 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -820,3 +820,12 @@ ARC_ENTRY sys_clone_wrapper
b ret_from_system_call
ARC_EXIT sys_clone_wrapper
+
+#ifdef CONFIG_ARC_DW2_UNWIND
+; Workaround for bug 94179 (STAR ):
+; Despite -fasynchronous-unwind-tables, linker is not making dwarf2 unwinder
+; section (.debug_frame) as loadable. So we force it here.
+; This also fixes STAR 9000487933 where the prev-workaround (objcopy --setflag)
+; would not work after a clean build due to kernel build system dependencies.
+.section .debug_frame, "wa",@progbits
+#endif
diff --git a/arch/arc/kernel/module.c b/arch/arc/kernel/module.c
index 723ad35..cdd3593 100644
--- a/arch/arc/kernel/module.c
+++ b/arch/arc/kernel/module.c
@@ -14,6 +14,7 @@
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/string.h>
+#include <asm/unwind.h>
static inline void arc_write_me(unsigned short *addr, unsigned long value)
{
@@ -21,14 +22,40 @@ static inline void arc_write_me(unsigned short *addr, unsigned long value)
*(addr + 1) = (value & 0xffff);
}
+/* ARC specific section quirks - before relocation loop in generic loader
+ *
+ * For dwarf unwinding out of modules, this needs to
+ * 1. Ensure the .debug_frame is allocatable (ARC Linker bug: despite
+ * -fasynchronous-unwind-tables it doesn't).
+ * 2. Since we are iterating thru sec hdr tbl anyways, make a note of
+ * the exact section index, for later use.
+ */
int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
char *secstr, struct module *mod)
{
+#ifdef CONFIG_ARC_DW2_UNWIND
+ int i;
+
+ mod->arch.unw_sec_idx = 0;
+ mod->arch.unw_info = NULL;
+
+ for (i = 1; i < hdr->e_shnum; i++) {
+ if (strcmp(secstr+sechdrs[i].sh_name, ".debug_frame") == 0) {
+ sechdrs[i].sh_flags |= SHF_ALLOC;
+ mod->arch.unw_sec_idx = i;
+ break;
+ }
+ }
+#endif
return 0;
}
void module_arch_cleanup(struct module *mod)
{
+#ifdef CONFIG_ARC_DW2_UNWIND
+ if (mod->arch.unw_info)
+ unwind_remove_table(mod->arch.unw_info, 0);
+#endif
}
int apply_relocate_add(Elf32_Shdr *sechdrs,
@@ -96,8 +123,23 @@ relo_err:
}
+/* Just before lift off: After sections have been relocated, we add the
+ * dwarf section to unwinder table pool
+ * This couldn't be done in module_frob_arch_sections() because
+ * relocations had not been applied by then
+ */
int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
struct module *mod)
{
+#ifdef CONFIG_ARC_DW2_UNWIND
+ void *unw;
+ int unwsec = mod->arch.unw_sec_idx;
+
+ if (unwsec) {
+ unw = unwind_add_table(mod, (void *)sechdrs[unwsec].sh_addr,
+ sechdrs[unwsec].sh_size);
+ mod->arch.unw_info = unw;
+ }
+#endif
return 0;
}
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index 4026b5a..6e3996c 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -23,6 +23,7 @@
#include <asm/irq.h>
#include <asm/arcregs.h>
#include <asm/prom.h>
+#include <asm/unwind.h>
#define FIX_PTR(x) __asm__ __volatile__(";" : "+r"(x))
@@ -105,6 +106,8 @@ void __init setup_arch(char **cmdline_p)
conswitchp = &dummy_con;
#endif
+ arc_unwind_init();
+ arc_unwind_setup();
}
/*
diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c
new file mode 100644
index 0000000..a8d0222
--- /dev/null
+++ b/arch/arc/kernel/unwind.c
@@ -0,0 +1,1329 @@
+/*
+ * Copyright (C) 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ * Copyright (C) 2002-2006 Novell, Inc.
+ * Jan Beulich <jbeulich@...ell.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * A simple API for unwinding kernel stacks. This is used for
+ * debugging and error reporting purposes. The kernel doesn't need
+ * full-blown stack unwinding with all the bells and whistles, so there
+ * is not much point in implementing the full Dwarf2 unwind API.
+ */
+
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/bootmem.h>
+#include <linux/sort.h>
+#include <linux/slab.h>
+#include <linux/stop_machine.h>
+#include <linux/uaccess.h>
+#include <linux/ptrace.h>
+#include <asm/sections.h>
+#include <asm/unaligned.h>
+#include <asm/unwind.h>
+
+extern char __start_unwind[], __end_unwind[];
+/* extern const u8 __start_unwind_hdr[], __end_unwind_hdr[];*/
+
+/* #define UNWIND_DEBUG */
+
+#ifdef UNWIND_DEBUG
+int dbg_unw;
+#define unw_debug(fmt, ...) \
+do { \
+ if (dbg_unw) \
+ pr_info(fmt, ##__VA_ARGS__); \
+} while (0);
+#else
+#define unw_debug(fmt, ...)
+#endif
+
+#define MAX_STACK_DEPTH 8
+
+#define EXTRA_INFO(f) { \
+ BUILD_BUG_ON_ZERO(offsetof(struct unwind_frame_info, f) \
+ % FIELD_SIZEOF(struct unwind_frame_info, f)) \
+ + offsetof(struct unwind_frame_info, f) \
+ / FIELD_SIZEOF(struct unwind_frame_info, f), \
+ FIELD_SIZEOF(struct unwind_frame_info, f) \
+ }
+#define PTREGS_INFO(f) EXTRA_INFO(regs.f)
+
+static const struct {
+ unsigned offs:BITS_PER_LONG / 2;
+ unsigned width:BITS_PER_LONG / 2;
+} reg_info[] = {
+UNW_REGISTER_INFO};
+
+#undef PTREGS_INFO
+#undef EXTRA_INFO
+
+#ifndef REG_INVALID
+#define REG_INVALID(r) (reg_info[r].width == 0)
+#endif
+
+#define DW_CFA_nop 0x00
+#define DW_CFA_set_loc 0x01
+#define DW_CFA_advance_loc1 0x02
+#define DW_CFA_advance_loc2 0x03
+#define DW_CFA_advance_loc4 0x04
+#define DW_CFA_offset_extended 0x05
+#define DW_CFA_restore_extended 0x06
+#define DW_CFA_undefined 0x07
+#define DW_CFA_same_value 0x08
+#define DW_CFA_register 0x09
+#define DW_CFA_remember_state 0x0a
+#define DW_CFA_restore_state 0x0b
+#define DW_CFA_def_cfa 0x0c
+#define DW_CFA_def_cfa_register 0x0d
+#define DW_CFA_def_cfa_offset 0x0e
+#define DW_CFA_def_cfa_expression 0x0f
+#define DW_CFA_expression 0x10
+#define DW_CFA_offset_extended_sf 0x11
+#define DW_CFA_def_cfa_sf 0x12
+#define DW_CFA_def_cfa_offset_sf 0x13
+#define DW_CFA_val_offset 0x14
+#define DW_CFA_val_offset_sf 0x15
+#define DW_CFA_val_expression 0x16
+#define DW_CFA_lo_user 0x1c
+#define DW_CFA_GNU_window_save 0x2d
+#define DW_CFA_GNU_args_size 0x2e
+#define DW_CFA_GNU_negative_offset_extended 0x2f
+#define DW_CFA_hi_user 0x3f
+
+#define DW_EH_PE_FORM 0x07
+#define DW_EH_PE_native 0x00
+#define DW_EH_PE_leb128 0x01
+#define DW_EH_PE_data2 0x02
+#define DW_EH_PE_data4 0x03
+#define DW_EH_PE_data8 0x04
+#define DW_EH_PE_signed 0x08
+#define DW_EH_PE_ADJUST 0x70
+#define DW_EH_PE_abs 0x00
+#define DW_EH_PE_pcrel 0x10
+#define DW_EH_PE_textrel 0x20
+#define DW_EH_PE_datarel 0x30
+#define DW_EH_PE_funcrel 0x40
+#define DW_EH_PE_aligned 0x50
+#define DW_EH_PE_indirect 0x80
+#define DW_EH_PE_omit 0xff
+
+typedef unsigned long uleb128_t;
+typedef signed long sleb128_t;
+
+static struct unwind_table {
+ struct {
+ unsigned long pc;
+ unsigned long range;
+ } core, init;
+ const void *address;
+ unsigned long size;
+ const unsigned char *header;
+ unsigned long hdrsz;
+ struct unwind_table *link;
+ const char *name;
+} root_table;
+
+struct unwind_item {
+ enum item_location {
+ Nowhere,
+ Memory,
+ Register,
+ Value
+ } where;
+ uleb128_t value;
+};
+
+struct unwind_state {
+ uleb128_t loc, org;
+ const u8 *cieStart, *cieEnd;
+ uleb128_t codeAlign;
+ sleb128_t dataAlign;
+ struct cfa {
+ uleb128_t reg, offs;
+ } cfa;
+ struct unwind_item regs[ARRAY_SIZE(reg_info)];
+ unsigned stackDepth:8;
+ unsigned version:8;
+ const u8 *label;
+ const u8 *stack[MAX_STACK_DEPTH];
+};
+
+static const struct cfa badCFA = { ARRAY_SIZE(reg_info), 1 };
+
+static struct unwind_table *find_table(unsigned long pc)
+{
+ struct unwind_table *table;
+
+ for (table = &root_table; table; table = table->link)
+ if ((pc >= table->core.pc
+ && pc < table->core.pc + table->core.range)
+ || (pc >= table->init.pc
+ && pc < table->init.pc + table->init.range))
+ break;
+
+ return table;
+}
+
+static unsigned long read_pointer(const u8 **pLoc,
+ const void *end, signed ptrType);
+
+static void init_unwind_table(struct unwind_table *table, const char *name,
+ const void *core_start, unsigned long core_size,
+ const void *init_start, unsigned long init_size,
+ const void *table_start, unsigned long table_size,
+ const u8 *header_start, unsigned long header_size)
+{
+ const u8 *ptr = header_start + 4;
+ const u8 *end = header_start + header_size;
+
+ table->core.pc = (unsigned long)core_start;
+ table->core.range = core_size;
+ table->init.pc = (unsigned long)init_start;
+ table->init.range = init_size;
+ table->address = table_start;
+ table->size = table_size;
+
+ /* See if the linker provided table looks valid. */
+ if (header_size <= 4
+ || header_start[0] != 1
+ || (void *)read_pointer(&ptr, end, header_start[1]) != table_start
+ || header_start[2] == DW_EH_PE_omit
+ || read_pointer(&ptr, end, header_start[2]) <= 0
+ || header_start[3] == DW_EH_PE_omit)
+ header_start = NULL;
+
+ table->hdrsz = header_size;
+ smp_wmb();
+ table->header = header_start;
+ table->link = NULL;
+ table->name = name;
+}
+
+void __init arc_unwind_init(void)
+{
+ init_unwind_table(&root_table, "kernel", _text, _end - _text, NULL, 0,
+ __start_unwind, __end_unwind - __start_unwind,
+ NULL, 0);
+ /*__start_unwind_hdr, __end_unwind_hdr - __start_unwind_hdr);*/
+}
+
+static const u32 bad_cie, not_fde;
+static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *);
+static signed fde_pointer_type(const u32 *cie);
+
+struct eh_frame_hdr_table_entry {
+ unsigned long start, fde;
+};
+
+static int cmp_eh_frame_hdr_table_entries(const void *p1, const void *p2)
+{
+ const struct eh_frame_hdr_table_entry *e1 = p1;
+ const struct eh_frame_hdr_table_entry *e2 = p2;
+
+ return (e1->start > e2->start) - (e1->start < e2->start);
+}
+
+static void swap_eh_frame_hdr_table_entries(void *p1, void *p2, int size)
+{
+ struct eh_frame_hdr_table_entry *e1 = p1;
+ struct eh_frame_hdr_table_entry *e2 = p2;
+ unsigned long v;
+
+ v = e1->start;
+ e1->start = e2->start;
+ e2->start = v;
+ v = e1->fde;
+ e1->fde = e2->fde;
+ e2->fde = v;
+}
+
+static void __init setup_unwind_table(struct unwind_table *table,
+ void *(*alloc) (unsigned long))
+{
+ const u8 *ptr;
+ unsigned long tableSize = table->size, hdrSize;
+ unsigned n;
+ const u32 *fde;
+ struct {
+ u8 version;
+ u8 eh_frame_ptr_enc;
+ u8 fde_count_enc;
+ u8 table_enc;
+ unsigned long eh_frame_ptr;
+ unsigned int fde_count;
+ struct eh_frame_hdr_table_entry table[];
+ } __attribute__ ((__packed__)) *header;
+
+ if (table->header)
+ return;
+
+ if (table->hdrsz)
+ pr_warn(".eh_frame_hdr for '%s' present but unusable\n",
+ table->name);
+
+ if (tableSize & (sizeof(*fde) - 1))
+ return;
+
+ for (fde = table->address, n = 0;
+ tableSize > sizeof(*fde) && tableSize - sizeof(*fde) >= *fde;
+ tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
+ const u32 *cie = cie_for_fde(fde, table);
+ signed ptrType;
+
+ if (cie == ¬_fde)
+ continue;
+ if (cie == NULL || cie == &bad_cie)
+ return;
+ ptrType = fde_pointer_type(cie);
+ if (ptrType < 0)
+ return;
+
+ ptr = (const u8 *)(fde + 2);
+ if (!read_pointer(&ptr, (const u8 *)(fde + 1) + *fde,
+ ptrType)) {
+ /* FIXME_Rajesh We have 4 instances of null addresses
+ * instead of the initial loc addr
+ * return;
+ */
+ }
+ ++n;
+ }
+
+ if (tableSize || !n)
+ return;
+
+ hdrSize = 4 + sizeof(unsigned long) + sizeof(unsigned int)
+ + 2 * n * sizeof(unsigned long);
+ header = alloc(hdrSize);
+ if (!header)
+ return;
+ header->version = 1;
+ header->eh_frame_ptr_enc = DW_EH_PE_abs | DW_EH_PE_native;
+ header->fde_count_enc = DW_EH_PE_abs | DW_EH_PE_data4;
+ header->table_enc = DW_EH_PE_abs | DW_EH_PE_native;
+ put_unaligned((unsigned long)table->address, &header->eh_frame_ptr);
+ BUILD_BUG_ON(offsetof(typeof(*header), fde_count)
+ % __alignof(typeof(header->fde_count)));
+ header->fde_count = n;
+
+ BUILD_BUG_ON(offsetof(typeof(*header), table)
+ % __alignof(typeof(*header->table)));
+ for (fde = table->address, tableSize = table->size, n = 0;
+ tableSize;
+ tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
+ /* const u32 *cie = fde + 1 - fde[1] / sizeof(*fde); */
+ const u32 *cie = (const u32 *)(fde[1]);
+
+ if (fde[1] == 0xffffffff)
+ continue; /* this is a CIE */
+ ptr = (const u8 *)(fde + 2);
+ header->table[n].start = read_pointer(&ptr,
+ (const u8 *)(fde + 1) +
+ *fde,
+ fde_pointer_type(cie));
+ header->table[n].fde = (unsigned long)fde;
+ ++n;
+ }
+ WARN_ON(n != header->fde_count);
+
+ sort(header->table,
+ n,
+ sizeof(*header->table),
+ cmp_eh_frame_hdr_table_entries, swap_eh_frame_hdr_table_entries);
+
+ table->hdrsz = hdrSize;
+ smp_wmb();
+ table->header = (const void *)header;
+}
+
+static void *__init balloc(unsigned long sz)
+{
+ return __alloc_bootmem_nopanic(sz,
+ sizeof(unsigned int),
+ __pa(MAX_DMA_ADDRESS));
+}
+
+void __init arc_unwind_setup(void)
+{
+ setup_unwind_table(&root_table, balloc);
+}
+
+#ifdef CONFIG_MODULES
+
+static struct unwind_table *last_table;
+
+/* Must be called with module_mutex held. */
+void *unwind_add_table(struct module *module, const void *table_start,
+ unsigned long table_size)
+{
+ struct unwind_table *table;
+
+ if (table_size <= 0)
+ return NULL;
+
+ table = kmalloc(sizeof(*table), GFP_KERNEL);
+ if (!table)
+ return NULL;
+
+ init_unwind_table(table, module->name,
+ module->module_core, module->core_size,
+ module->module_init, module->init_size,
+ table_start, table_size,
+ NULL, 0);
+
+#ifdef UNWIND_DEBUG
+ unw_debug("Table added for [%s] %lx %lx\n",
+ module->name, table->core.pc, table->core.range);
+#endif
+ if (last_table)
+ last_table->link = table;
+ else
+ root_table.link = table;
+ last_table = table;
+
+ return table;
+}
+
+struct unlink_table_info {
+ struct unwind_table *table;
+ int init_only;
+};
+
+static int unlink_table(void *arg)
+{
+ struct unlink_table_info *info = arg;
+ struct unwind_table *table = info->table, *prev;
+
+ for (prev = &root_table; prev->link && prev->link != table;
+ prev = prev->link)
+ ;
+
+ if (prev->link) {
+ if (info->init_only) {
+ table->init.pc = 0;
+ table->init.range = 0;
+ info->table = NULL;
+ } else {
+ prev->link = table->link;
+ if (!prev->link)
+ last_table = prev;
+ }
+ } else
+ info->table = NULL;
+
+ return 0;
+}
+
+/* Must be called with module_mutex held. */
+void unwind_remove_table(void *handle, int init_only)
+{
+ struct unwind_table *table = handle;
+ struct unlink_table_info info;
+
+ if (!table || table == &root_table)
+ return;
+
+ if (init_only && table == last_table) {
+ table->init.pc = 0;
+ table->init.range = 0;
+ return;
+ }
+
+ info.table = table;
+ info.init_only = init_only;
+
+ unlink_table(&info); /* XXX: SMP */
+ kfree(table);
+}
+
+#endif /* CONFIG_MODULES */
+
+static uleb128_t get_uleb128(const u8 **pcur, const u8 *end)
+{
+ const u8 *cur = *pcur;
+ uleb128_t value;
+ unsigned shift;
+
+ for (shift = 0, value = 0; cur < end; shift += 7) {
+ if (shift + 7 > 8 * sizeof(value)
+ && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) {
+ cur = end + 1;
+ break;
+ }
+ value |= (uleb128_t) (*cur & 0x7f) << shift;
+ if (!(*cur++ & 0x80))
+ break;
+ }
+ *pcur = cur;
+
+ return value;
+}
+
+static sleb128_t get_sleb128(const u8 **pcur, const u8 *end)
+{
+ const u8 *cur = *pcur;
+ sleb128_t value;
+ unsigned shift;
+
+ for (shift = 0, value = 0; cur < end; shift += 7) {
+ if (shift + 7 > 8 * sizeof(value)
+ && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) {
+ cur = end + 1;
+ break;
+ }
+ value |= (sleb128_t) (*cur & 0x7f) << shift;
+ if (!(*cur & 0x80)) {
+ value |= -(*cur++ & 0x40) << shift;
+ break;
+ }
+ }
+ *pcur = cur;
+
+ return value;
+}
+
+static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *table)
+{
+ const u32 *cie;
+
+ if (!*fde || (*fde & (sizeof(*fde) - 1)))
+ return &bad_cie;
+
+ if (fde[1] == 0xffffffff)
+ return ¬_fde; /* this is a CIE */
+
+ if ((fde[1] & (sizeof(*fde) - 1)))
+/* || fde[1] > (unsigned long)(fde + 1) - (unsigned long)table->address) */
+ return NULL; /* this is not a valid FDE */
+
+ /* cie = fde + 1 - fde[1] / sizeof(*fde); */
+ cie = (u32 *) fde[1];
+
+ if (*cie <= sizeof(*cie) + 4 || *cie >= fde[1] - sizeof(*fde)
+ || (*cie & (sizeof(*cie) - 1))
+ || (cie[1] != 0xffffffff))
+ return NULL; /* this is not a (valid) CIE */
+ return cie;
+}
+
+static unsigned long read_pointer(const u8 **pLoc, const void *end,
+ signed ptrType)
+{
+ unsigned long value = 0;
+ union {
+ const u8 *p8;
+ const u16 *p16u;
+ const s16 *p16s;
+ const u32 *p32u;
+ const s32 *p32s;
+ const unsigned long *pul;
+ } ptr;
+
+ if (ptrType < 0 || ptrType == DW_EH_PE_omit)
+ return 0;
+ ptr.p8 = *pLoc;
+ switch (ptrType & DW_EH_PE_FORM) {
+ case DW_EH_PE_data2:
+ if (end < (const void *)(ptr.p16u + 1))
+ return 0;
+ if (ptrType & DW_EH_PE_signed)
+ value = get_unaligned((u16 *) ptr.p16s++);
+ else
+ value = get_unaligned((u16 *) ptr.p16u++);
+ break;
+ case DW_EH_PE_data4:
+#ifdef CONFIG_64BIT
+ if (end < (const void *)(ptr.p32u + 1))
+ return 0;
+ if (ptrType & DW_EH_PE_signed)
+ value = get_unaligned(ptr.p32s++);
+ else
+ value = get_unaligned(ptr.p32u++);
+ break;
+ case DW_EH_PE_data8:
+ BUILD_BUG_ON(sizeof(u64) != sizeof(value));
+#else
+ BUILD_BUG_ON(sizeof(u32) != sizeof(value));
+#endif
+ case DW_EH_PE_native:
+ if (end < (const void *)(ptr.pul + 1))
+ return 0;
+ value = get_unaligned((unsigned long *)ptr.pul++);
+ break;
+ case DW_EH_PE_leb128:
+ BUILD_BUG_ON(sizeof(uleb128_t) > sizeof(value));
+ value = ptrType & DW_EH_PE_signed ? get_sleb128(&ptr.p8, end)
+ : get_uleb128(&ptr.p8, end);
+ if ((const void *)ptr.p8 > end)
+ return 0;
+ break;
+ default:
+ return 0;
+ }
+ switch (ptrType & DW_EH_PE_ADJUST) {
+ case DW_EH_PE_abs:
+ break;
+ case DW_EH_PE_pcrel:
+ value += (unsigned long)*pLoc;
+ break;
+ default:
+ return 0;
+ }
+ if ((ptrType & DW_EH_PE_indirect)
+ && __get_user(value, (unsigned long __user *)value))
+ return 0;
+ *pLoc = ptr.p8;
+
+ return value;
+}
+
+static signed fde_pointer_type(const u32 *cie)
+{
+ const u8 *ptr = (const u8 *)(cie + 2);
+ unsigned version = *ptr;
+
+ if (version != 1)
+ return -1; /* unsupported */
+
+ if (*++ptr) {
+ const char *aug;
+ const u8 *end = (const u8 *)(cie + 1) + *cie;
+ uleb128_t len;
+
+ /* check if augmentation size is first (and thus present) */
+ if (*ptr != 'z')
+ return -1;
+
+ /* check if augmentation string is nul-terminated */
+ aug = (const void *)ptr;
+ ptr = memchr(aug, 0, end - ptr);
+ if (ptr == NULL)
+ return -1;
+
+ ++ptr; /* skip terminator */
+ get_uleb128(&ptr, end); /* skip code alignment */
+ get_sleb128(&ptr, end); /* skip data alignment */
+ /* skip return address column */
+ version <= 1 ? (void) ++ptr : (void)get_uleb128(&ptr, end);
+ len = get_uleb128(&ptr, end); /* augmentation length */
+
+ if (ptr + len < ptr || ptr + len > end)
+ return -1;
+
+ end = ptr + len;
+ while (*++aug) {
+ if (ptr >= end)
+ return -1;
+ switch (*aug) {
+ case 'L':
+ ++ptr;
+ break;
+ case 'P':{
+ signed ptrType = *ptr++;
+
+ if (!read_pointer(&ptr, end, ptrType)
+ || ptr > end)
+ return -1;
+ }
+ break;
+ case 'R':
+ return *ptr;
+ default:
+ return -1;
+ }
+ }
+ }
+ return DW_EH_PE_native | DW_EH_PE_abs;
+}
+
+static int advance_loc(unsigned long delta, struct unwind_state *state)
+{
+ state->loc += delta * state->codeAlign;
+
+ /* FIXME_Rajesh: Probably we are defining for the initial range as well;
+ return delta > 0;
+ */
+ unw_debug("delta %3lu => loc 0x%lx: ", delta, state->loc);
+ return 1;
+}
+
+static void set_rule(uleb128_t reg, enum item_location where, uleb128_t value,
+ struct unwind_state *state)
+{
+ if (reg < ARRAY_SIZE(state->regs)) {
+ state->regs[reg].where = where;
+ state->regs[reg].value = value;
+
+#ifdef UNWIND_DEBUG
+ unw_debug("r%lu: ", reg);
+ switch (where) {
+ case Nowhere:
+ unw_debug("s ");
+ break;
+ case Memory:
+ unw_debug("c(%lu) ", value);
+ break;
+ case Register:
+ unw_debug("r(%lu) ", value);
+ break;
+ case Value:
+ unw_debug("v(%lu) ", value);
+ break;
+ default:
+ break;
+ }
+#endif
+ }
+}
+
+static int processCFI(const u8 *start, const u8 *end, unsigned long targetLoc,
+ signed ptrType, struct unwind_state *state)
+{
+ union {
+ const u8 *p8;
+ const u16 *p16;
+ const u32 *p32;
+ } ptr;
+ int result = 1;
+ u8 opcode;
+
+ if (start != state->cieStart) {
+ state->loc = state->org;
+ result =
+ processCFI(state->cieStart, state->cieEnd, 0, ptrType,
+ state);
+ if (targetLoc == 0 && state->label == NULL)
+ return result;
+ }
+ for (ptr.p8 = start; result && ptr.p8 < end;) {
+ switch (*ptr.p8 >> 6) {
+ uleb128_t value;
+
+ case 0:
+ opcode = *ptr.p8++;
+
+ switch (opcode) {
+ case DW_CFA_nop:
+ unw_debug("cfa nop ");
+ break;
+ case DW_CFA_set_loc:
+ state->loc = read_pointer(&ptr.p8, end,
+ ptrType);
+ if (state->loc == 0)
+ result = 0;
+ unw_debug("cfa_set_loc: 0x%lx ", state->loc);
+ break;
+ case DW_CFA_advance_loc1:
+ unw_debug("\ncfa advance loc1:");
+ result = ptr.p8 < end
+ && advance_loc(*ptr.p8++, state);
+ break;
+ case DW_CFA_advance_loc2:
+ value = *ptr.p8++;
+ value += *ptr.p8++ << 8;
+ unw_debug("\ncfa advance loc2:");
+ result = ptr.p8 <= end + 2
+ /* && advance_loc(*ptr.p16++, state); */
+ && advance_loc(value, state);
+ break;
+ case DW_CFA_advance_loc4:
+ unw_debug("\ncfa advance loc4:");
+ result = ptr.p8 <= end + 4
+ && advance_loc(*ptr.p32++, state);
+ break;
+ case DW_CFA_offset_extended:
+ value = get_uleb128(&ptr.p8, end);
+ unw_debug("cfa_offset_extended: ");
+ set_rule(value, Memory,
+ get_uleb128(&ptr.p8, end), state);
+ break;
+ case DW_CFA_val_offset:
+ value = get_uleb128(&ptr.p8, end);
+ set_rule(value, Value,
+ get_uleb128(&ptr.p8, end), state);
+ break;
+ case DW_CFA_offset_extended_sf:
+ value = get_uleb128(&ptr.p8, end);
+ set_rule(value, Memory,
+ get_sleb128(&ptr.p8, end), state);
+ break;
+ case DW_CFA_val_offset_sf:
+ value = get_uleb128(&ptr.p8, end);
+ set_rule(value, Value,
+ get_sleb128(&ptr.p8, end), state);
+ break;
+ case DW_CFA_restore_extended:
+ unw_debug("cfa_restore_extended: ");
+ case DW_CFA_undefined:
+ unw_debug("cfa_undefined: ");
+ case DW_CFA_same_value:
+ unw_debug("cfa_same_value: ");
+ set_rule(get_uleb128(&ptr.p8, end), Nowhere, 0,
+ state);
+ break;
+ case DW_CFA_register:
+ unw_debug("cfa_register: ");
+ value = get_uleb128(&ptr.p8, end);
+ set_rule(value,
+ Register,
+ get_uleb128(&ptr.p8, end), state);
+ break;
+ case DW_CFA_remember_state:
+ unw_debug("cfa_remember_state: ");
+ if (ptr.p8 == state->label) {
+ state->label = NULL;
+ return 1;
+ }
+ if (state->stackDepth >= MAX_STACK_DEPTH)
+ return 0;
+ state->stack[state->stackDepth++] = ptr.p8;
+ break;
+ case DW_CFA_restore_state:
+ unw_debug("cfa_restore_state: ");
+ if (state->stackDepth) {
+ const uleb128_t loc = state->loc;
+ const u8 *label = state->label;
+
+ state->label =
+ state->stack[state->stackDepth - 1];
+ memcpy(&state->cfa, &badCFA,
+ sizeof(state->cfa));
+ memset(state->regs, 0,
+ sizeof(state->regs));
+ state->stackDepth = 0;
+ result =
+ processCFI(start, end, 0, ptrType,
+ state);
+ state->loc = loc;
+ state->label = label;
+ } else
+ return 0;
+ break;
+ case DW_CFA_def_cfa:
+ state->cfa.reg = get_uleb128(&ptr.p8, end);
+ unw_debug("cfa_def_cfa: r%lu ", state->cfa.reg);
+ /*nobreak*/
+ case DW_CFA_def_cfa_offset:
+ state->cfa.offs = get_uleb128(&ptr.p8, end);
+ unw_debug("cfa_def_cfa_offset: 0x%lx ",
+ state->cfa.offs);
+ break;
+ case DW_CFA_def_cfa_sf:
+ state->cfa.reg = get_uleb128(&ptr.p8, end);
+ /*nobreak */
+ case DW_CFA_def_cfa_offset_sf:
+ state->cfa.offs = get_sleb128(&ptr.p8, end)
+ * state->dataAlign;
+ break;
+ case DW_CFA_def_cfa_register:
+ unw_debug("cfa_def_cfa_regsiter: ");
+ state->cfa.reg = get_uleb128(&ptr.p8, end);
+ break;
+ /*todo case DW_CFA_def_cfa_expression: */
+ /*todo case DW_CFA_expression: */
+ /*todo case DW_CFA_val_expression: */
+ case DW_CFA_GNU_args_size:
+ get_uleb128(&ptr.p8, end);
+ break;
+ case DW_CFA_GNU_negative_offset_extended:
+ value = get_uleb128(&ptr.p8, end);
+ set_rule(value,
+ Memory,
+ (uleb128_t) 0 - get_uleb128(&ptr.p8,
+ end),
+ state);
+ break;
+ case DW_CFA_GNU_window_save:
+ default:
+ unw_debug("UNKNOW OPCODE 0x%x\n", opcode);
+ result = 0;
+ break;
+ }
+ break;
+ case 1:
+ unw_debug("\ncfa_adv_loc: ");
+ result = advance_loc(*ptr.p8++ & 0x3f, state);
+ break;
+ case 2:
+ unw_debug("cfa_offset: ");
+ value = *ptr.p8++ & 0x3f;
+ set_rule(value, Memory, get_uleb128(&ptr.p8, end),
+ state);
+ break;
+ case 3:
+ unw_debug("cfa_restore: ");
+ set_rule(*ptr.p8++ & 0x3f, Nowhere, 0, state);
+ break;
+ }
+
+ if (ptr.p8 > end)
+ result = 0;
+ if (result && targetLoc != 0 && targetLoc < state->loc)
+ return 1;
+ }
+
+ return result && ptr.p8 == end && (targetLoc == 0 || (
+ /*todo While in theory this should apply, gcc in practice omits
+ everything past the function prolog, and hence the location
+ never reaches the end of the function.
+ targetLoc < state->loc && */ state->label == NULL));
+}
+
+/* Unwind to previous to frame. Returns 0 if successful, negative
+ * number in case of an error. */
+int arc_unwind(struct unwind_frame_info *frame)
+{
+#define FRAME_REG(r, t) (((t *)frame)[reg_info[r].offs])
+ const u32 *fde = NULL, *cie = NULL;
+ const u8 *ptr = NULL, *end = NULL;
+ unsigned long pc = UNW_PC(frame) - frame->call_frame;
+ unsigned long startLoc = 0, endLoc = 0, cfa;
+ unsigned i;
+ signed ptrType = -1;
+ uleb128_t retAddrReg = 0;
+ const struct unwind_table *table;
+ struct unwind_state state;
+ unsigned long *fptr;
+ unsigned long addr;
+
+ unw_debug("\n\nUNWIND FRAME:\n");
+ unw_debug("PC: 0x%lx BLINK: 0x%lx, SP: 0x%lx, FP: 0x%x\n",
+ UNW_PC(frame), UNW_BLINK(frame), UNW_SP(frame),
+ UNW_FP(frame));
+
+ if (UNW_PC(frame) == 0)
+ return -EINVAL;
+
+#ifdef UNWIND_DEBUG
+ {
+ unsigned long *sptr = (unsigned long *)UNW_SP(frame);
+ unw_debug("\nStack Dump:\n");
+ for (i = 0; i < 20; i++, sptr++)
+ unw_debug("0x%p: 0x%lx\n", sptr, *sptr);
+ unw_debug("\n");
+ }
+#endif
+
+ table = find_table(pc);
+ if (table != NULL
+ && !(table->size & (sizeof(*fde) - 1))) {
+ const u8 *hdr = table->header;
+ unsigned long tableSize;
+
+ smp_rmb();
+ if (hdr && hdr[0] == 1) {
+ switch (hdr[3] & DW_EH_PE_FORM) {
+ case DW_EH_PE_native:
+ tableSize = sizeof(unsigned long);
+ break;
+ case DW_EH_PE_data2:
+ tableSize = 2;
+ break;
+ case DW_EH_PE_data4:
+ tableSize = 4;
+ break;
+ case DW_EH_PE_data8:
+ tableSize = 8;
+ break;
+ default:
+ tableSize = 0;
+ break;
+ }
+ ptr = hdr + 4;
+ end = hdr + table->hdrsz;
+ if (tableSize && read_pointer(&ptr, end, hdr[1])
+ == (unsigned long)table->address
+ && (i = read_pointer(&ptr, end, hdr[2])) > 0
+ && i == (end - ptr) / (2 * tableSize)
+ && !((end - ptr) % (2 * tableSize))) {
+ do {
+ const u8 *cur =
+ ptr + (i / 2) * (2 * tableSize);
+
+ startLoc = read_pointer(&cur,
+ cur + tableSize,
+ hdr[3]);
+ if (pc < startLoc)
+ i /= 2;
+ else {
+ ptr = cur - tableSize;
+ i = (i + 1) / 2;
+ }
+ } while (startLoc && i > 1);
+ if (i == 1
+ && (startLoc = read_pointer(&ptr,
+ ptr + tableSize,
+ hdr[3])) != 0
+ && pc >= startLoc)
+ fde = (void *)read_pointer(&ptr,
+ ptr +
+ tableSize,
+ hdr[3]);
+ }
+ }
+
+ if (fde != NULL) {
+ cie = cie_for_fde(fde, table);
+ ptr = (const u8 *)(fde + 2);
+ if (cie != NULL
+ && cie != &bad_cie
+ && cie != ¬_fde
+ && (ptrType = fde_pointer_type(cie)) >= 0
+ && read_pointer(&ptr,
+ (const u8 *)(fde + 1) + *fde,
+ ptrType) == startLoc) {
+ if (!(ptrType & DW_EH_PE_indirect))
+ ptrType &=
+ DW_EH_PE_FORM | DW_EH_PE_signed;
+ endLoc =
+ startLoc + read_pointer(&ptr,
+ (const u8 *)(fde +
+ 1) +
+ *fde, ptrType);
+ if (pc >= endLoc)
+ fde = NULL;
+ } else
+ fde = NULL;
+ }
+ if (fde == NULL) {
+ for (fde = table->address, tableSize = table->size;
+ cie = NULL, tableSize > sizeof(*fde)
+ && tableSize - sizeof(*fde) >= *fde;
+ tableSize -= sizeof(*fde) + *fde,
+ fde += 1 + *fde / sizeof(*fde)) {
+ cie = cie_for_fde(fde, table);
+ if (cie == &bad_cie) {
+ cie = NULL;
+ break;
+ }
+ if (cie == NULL
+ || cie == ¬_fde
+ || (ptrType = fde_pointer_type(cie)) < 0)
+ continue;
+ ptr = (const u8 *)(fde + 2);
+ startLoc = read_pointer(&ptr,
+ (const u8 *)(fde + 1) +
+ *fde, ptrType);
+ if (!startLoc)
+ continue;
+ if (!(ptrType & DW_EH_PE_indirect))
+ ptrType &=
+ DW_EH_PE_FORM | DW_EH_PE_signed;
+ endLoc =
+ startLoc + read_pointer(&ptr,
+ (const u8 *)(fde +
+ 1) +
+ *fde, ptrType);
+ if (pc >= startLoc && pc < endLoc)
+ break;
+ }
+ }
+ }
+ if (cie != NULL) {
+ memset(&state, 0, sizeof(state));
+ state.cieEnd = ptr; /* keep here temporarily */
+ ptr = (const u8 *)(cie + 2);
+ end = (const u8 *)(cie + 1) + *cie;
+ frame->call_frame = 1;
+ if ((state.version = *ptr) != 1)
+ cie = NULL; /* unsupported version */
+ else if (*++ptr) {
+ /* check if augmentation size is first (thus present) */
+ if (*ptr == 'z') {
+ while (++ptr < end && *ptr) {
+ switch (*ptr) {
+ /* chk for ignorable or already handled
+ * nul-terminated augmentation string */
+ case 'L':
+ case 'P':
+ case 'R':
+ continue;
+ case 'S':
+ frame->call_frame = 0;
+ continue;
+ default:
+ break;
+ }
+ break;
+ }
+ }
+ if (ptr >= end || *ptr)
+ cie = NULL;
+ }
+ ++ptr;
+ }
+ if (cie != NULL) {
+ /* get code aligment factor */
+ state.codeAlign = get_uleb128(&ptr, end);
+ /* get data aligment factor */
+ state.dataAlign = get_sleb128(&ptr, end);
+ if (state.codeAlign == 0 || state.dataAlign == 0 || ptr >= end)
+ cie = NULL;
+ else {
+ retAddrReg =
+ state.version <= 1 ? *ptr++ : get_uleb128(&ptr,
+ end);
+ unw_debug("CIE Frame Info:\n");
+ unw_debug("return Address register 0x%lx\n",
+ retAddrReg);
+ unw_debug("data Align: %ld\n", state.dataAlign);
+ unw_debug("code Align: %lu\n", state.codeAlign);
+ /* skip augmentation */
+ if (((const char *)(cie + 2))[1] == 'z') {
+ uleb128_t augSize = get_uleb128(&ptr, end);
+
+ ptr += augSize;
+ }
+ if (ptr > end || retAddrReg >= ARRAY_SIZE(reg_info)
+ || REG_INVALID(retAddrReg)
+ || reg_info[retAddrReg].width !=
+ sizeof(unsigned long))
+ cie = NULL;
+ }
+ }
+ if (cie != NULL) {
+ state.cieStart = ptr;
+ ptr = state.cieEnd;
+ state.cieEnd = end;
+ end = (const u8 *)(fde + 1) + *fde;
+ /* skip augmentation */
+ if (((const char *)(cie + 2))[1] == 'z') {
+ uleb128_t augSize = get_uleb128(&ptr, end);
+
+ if ((ptr += augSize) > end)
+ fde = NULL;
+ }
+ }
+ if (cie == NULL || fde == NULL) {
+#ifdef CONFIG_FRAME_POINTER
+ unsigned long top, bottom;
+
+ top = STACK_TOP_UNW(frame->task);
+ bottom = STACK_BOTTOM_UNW(frame->task);
+#if FRAME_RETADDR_OFFSET < 0
+ if (UNW_SP(frame) < top && UNW_FP(frame) <= UNW_SP(frame)
+ && bottom < UNW_FP(frame)
+#else
+ if (UNW_SP(frame) > top && UNW_FP(frame) >= UNW_SP(frame)
+ && bottom > UNW_FP(frame)
+#endif
+ && !((UNW_SP(frame) | UNW_FP(frame))
+ & (sizeof(unsigned long) - 1))) {
+ unsigned long link;
+
+ if (!__get_user(link, (unsigned long *)
+ (UNW_FP(frame) + FRAME_LINK_OFFSET))
+#if FRAME_RETADDR_OFFSET < 0
+ && link > bottom && link < UNW_FP(frame)
+#else
+ && link > UNW_FP(frame) && link < bottom
+#endif
+ && !(link & (sizeof(link) - 1))
+ && !__get_user(UNW_PC(frame),
+ (unsigned long *)(UNW_FP(frame)
+ + FRAME_RETADDR_OFFSET)))
+ {
+ UNW_SP(frame) =
+ UNW_FP(frame) + FRAME_RETADDR_OFFSET
+#if FRAME_RETADDR_OFFSET < 0
+ -
+#else
+ +
+#endif
+ sizeof(UNW_PC(frame));
+ UNW_FP(frame) = link;
+ return 0;
+ }
+ }
+#endif
+ return -ENXIO;
+ }
+ state.org = startLoc;
+ memcpy(&state.cfa, &badCFA, sizeof(state.cfa));
+
+ unw_debug("\nProcess instructions\n");
+
+ /* process instructions
+ * For ARC, we optimize by having blink(retAddrReg) with
+ * the sameValue in the leaf function, so we should not check
+ * state.regs[retAddrReg].where == Nowhere
+ */
+ if (!processCFI(ptr, end, pc, ptrType, &state)
+ || state.loc > endLoc
+/* || state.regs[retAddrReg].where == Nowhere */
+ || state.cfa.reg >= ARRAY_SIZE(reg_info)
+ || reg_info[state.cfa.reg].width != sizeof(unsigned long)
+ || state.cfa.offs % sizeof(unsigned long))
+ return -EIO;
+
+#ifdef UNWIND_DEBUG
+ unw_debug("\n");
+
+ unw_debug("\nRegister State Based on the rules parsed from FDE:\n");
+ for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
+
+ if (REG_INVALID(i))
+ continue;
+
+ switch (state.regs[i].where) {
+ case Nowhere:
+ break;
+ case Memory:
+ unw_debug(" r%d: c(%lu),", i, state.regs[i].value);
+ break;
+ case Register:
+ unw_debug(" r%d: r(%lu),", i, state.regs[i].value);
+ break;
+ case Value:
+ unw_debug(" r%d: v(%lu),", i, state.regs[i].value);
+ break;
+ }
+ }
+
+ unw_debug("\n");
+#endif
+
+ /* update frame */
+#ifndef CONFIG_AS_CFI_SIGNAL_FRAME
+ if (frame->call_frame
+ && !UNW_DEFAULT_RA(state.regs[retAddrReg], state.dataAlign))
+ frame->call_frame = 0;
+#endif
+ cfa = FRAME_REG(state.cfa.reg, unsigned long) + state.cfa.offs;
+ startLoc = min_t(unsigned long, UNW_SP(frame), cfa);
+ endLoc = max_t(unsigned long, UNW_SP(frame), cfa);
+ if (STACK_LIMIT(startLoc) != STACK_LIMIT(endLoc)) {
+ startLoc = min(STACK_LIMIT(cfa), cfa);
+ endLoc = max(STACK_LIMIT(cfa), cfa);
+ }
+
+ unw_debug("\nCFA reg: 0x%lx, offset: 0x%lx => 0x%lx\n",
+ state.cfa.reg, state.cfa.offs, cfa);
+
+ for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
+ if (REG_INVALID(i)) {
+ if (state.regs[i].where == Nowhere)
+ continue;
+ return -EIO;
+ }
+ switch (state.regs[i].where) {
+ default:
+ break;
+ case Register:
+ if (state.regs[i].value >= ARRAY_SIZE(reg_info)
+ || REG_INVALID(state.regs[i].value)
+ || reg_info[i].width >
+ reg_info[state.regs[i].value].width)
+ return -EIO;
+ switch (reg_info[state.regs[i].value].width) {
+ case sizeof(u8):
+ state.regs[i].value =
+ FRAME_REG(state.regs[i].value, const u8);
+ break;
+ case sizeof(u16):
+ state.regs[i].value =
+ FRAME_REG(state.regs[i].value, const u16);
+ break;
+ case sizeof(u32):
+ state.regs[i].value =
+ FRAME_REG(state.regs[i].value, const u32);
+ break;
+#ifdef CONFIG_64BIT
+ case sizeof(u64):
+ state.regs[i].value =
+ FRAME_REG(state.regs[i].value, const u64);
+ break;
+#endif
+ default:
+ return -EIO;
+ }
+ break;
+ }
+ }
+
+ unw_debug("\nRegister state after evaluation with realtime Stack:\n");
+ fptr = (unsigned long *)(&frame->regs);
+ for (i = 0; i < ARRAY_SIZE(state.regs); ++i, fptr++) {
+
+ if (REG_INVALID(i))
+ continue;
+ switch (state.regs[i].where) {
+ case Nowhere:
+ if (reg_info[i].width != sizeof(UNW_SP(frame))
+ || &FRAME_REG(i, __typeof__(UNW_SP(frame)))
+ != &UNW_SP(frame))
+ continue;
+ UNW_SP(frame) = cfa;
+ break;
+ case Register:
+ switch (reg_info[i].width) {
+ case sizeof(u8):
+ FRAME_REG(i, u8) = state.regs[i].value;
+ break;
+ case sizeof(u16):
+ FRAME_REG(i, u16) = state.regs[i].value;
+ break;
+ case sizeof(u32):
+ FRAME_REG(i, u32) = state.regs[i].value;
+ break;
+#ifdef CONFIG_64BIT
+ case sizeof(u64):
+ FRAME_REG(i, u64) = state.regs[i].value;
+ break;
+#endif
+ default:
+ return -EIO;
+ }
+ break;
+ case Value:
+ if (reg_info[i].width != sizeof(unsigned long))
+ return -EIO;
+ FRAME_REG(i, unsigned long) = cfa + state.regs[i].value
+ * state.dataAlign;
+ break;
+ case Memory:
+ addr = cfa + state.regs[i].value * state.dataAlign;
+
+ if ((state.regs[i].value * state.dataAlign)
+ % sizeof(unsigned long)
+ || addr < startLoc
+ || addr + sizeof(unsigned long) < addr
+ || addr + sizeof(unsigned long) > endLoc)
+ return -EIO;
+
+ switch (reg_info[i].width) {
+ case sizeof(u8):
+ __get_user(FRAME_REG(i, u8),
+ (u8 __user *)addr);
+ break;
+ case sizeof(u16):
+ __get_user(FRAME_REG(i, u16),
+ (u16 __user *)addr);
+ break;
+ case sizeof(u32):
+ __get_user(FRAME_REG(i, u32),
+ (u32 __user *)addr);
+ break;
+#ifdef CONFIG_64BIT
+ case sizeof(u64):
+ __get_user(FRAME_REG(i, u64),
+ (u64 __user *)addr);
+ break;
+#endif
+ default:
+ return -EIO;
+ }
+
+ break;
+ }
+ unw_debug("r%d: 0x%lx ", i, *fptr);
+ }
+
+ return 0;
+#undef FRAME_REG
+}
+EXPORT_SYMBOL(arc_unwind);
diff --git a/arch/arc/kernel/vmlinux.lds.S b/arch/arc/kernel/vmlinux.lds.S
index 67c35bd..56c074e 100644
--- a/arch/arc/kernel/vmlinux.lds.S
+++ b/arch/arc/kernel/vmlinux.lds.S
@@ -101,17 +101,38 @@ SECTIONS
BSS_SECTION(0, 0, 0)
+#ifdef CONFIG_ARC_DW2_UNWIND
+ . = ALIGN(PAGE_SIZE);
+ .debug_frame : {
+ __start_unwind = .;
+ *(.debug_frame)
+ __end_unwind = .;
+ }
+#else
+ /DISCARD/ : { *(.debug_frame) }
+#endif
+
NOTES
. = ALIGN(PAGE_SIZE);
_end = . ;
STABS_DEBUG
- DWARF_DEBUG
DISCARDS
.arcextmap 0 : {
*(.gnu.linkonce.arcextmap.*)
*(.arcextmap.*)
}
+
+ /* open-coded because we need .debug_frame seperately for unwinding */
+ .debug_aranges 0 : { *(.debug_aranges) }
+ .debug_pubnames 0 : { *(.debug_pubnames) }
+ .debug_info 0 : { *(.debug_info) }
+ .debug_abbrev 0 : { *(.debug_abbrev) }
+ .debug_line 0 : { *(.debug_line) }
+ .debug_str 0 : { *(.debug_str) }
+ .debug_loc 0 : { *(.debug_loc) }
+ .debug_macinfo 0 : { *(.debug_macinfo) }
+
}
--
1.7.4.1
--
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