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1318 lines
32 KiB
1318 lines
32 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (C) 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) |
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* Copyright (C) 2002-2006 Novell, Inc. |
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* Jan Beulich <[email protected]> |
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* |
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* A simple API for unwinding kernel stacks. This is used for |
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* debugging and error reporting purposes. The kernel doesn't need |
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* full-blown stack unwinding with all the bells and whistles, so there |
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* is not much point in implementing the full Dwarf2 unwind API. |
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*/ |
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|
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#include <linux/sched.h> |
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#include <linux/module.h> |
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#include <linux/memblock.h> |
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#include <linux/sort.h> |
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#include <linux/slab.h> |
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#include <linux/stop_machine.h> |
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#include <linux/uaccess.h> |
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#include <linux/ptrace.h> |
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#include <asm/sections.h> |
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#include <asm/unaligned.h> |
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#include <asm/unwind.h> |
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|
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extern char __start_unwind[], __end_unwind[]; |
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/* extern const u8 __start_unwind_hdr[], __end_unwind_hdr[];*/ |
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|
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/* #define UNWIND_DEBUG */ |
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|
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#ifdef UNWIND_DEBUG |
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int dbg_unw; |
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#define unw_debug(fmt, ...) \ |
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do { \ |
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if (dbg_unw) \ |
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pr_info(fmt, ##__VA_ARGS__); \ |
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} while (0); |
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#else |
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#define unw_debug(fmt, ...) |
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#endif |
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|
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#define MAX_STACK_DEPTH 8 |
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|
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#define EXTRA_INFO(f) { \ |
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BUILD_BUG_ON_ZERO(offsetof(struct unwind_frame_info, f) \ |
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% sizeof_field(struct unwind_frame_info, f)) \ |
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+ offsetof(struct unwind_frame_info, f) \ |
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/ sizeof_field(struct unwind_frame_info, f), \ |
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sizeof_field(struct unwind_frame_info, f) \ |
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} |
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#define PTREGS_INFO(f) EXTRA_INFO(regs.f) |
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|
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static const struct { |
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unsigned offs:BITS_PER_LONG / 2; |
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unsigned width:BITS_PER_LONG / 2; |
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} reg_info[] = { |
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UNW_REGISTER_INFO}; |
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|
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#undef PTREGS_INFO |
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#undef EXTRA_INFO |
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|
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#ifndef REG_INVALID |
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#define REG_INVALID(r) (reg_info[r].width == 0) |
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#endif |
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|
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#define DW_CFA_nop 0x00 |
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#define DW_CFA_set_loc 0x01 |
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#define DW_CFA_advance_loc1 0x02 |
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#define DW_CFA_advance_loc2 0x03 |
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#define DW_CFA_advance_loc4 0x04 |
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#define DW_CFA_offset_extended 0x05 |
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#define DW_CFA_restore_extended 0x06 |
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#define DW_CFA_undefined 0x07 |
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#define DW_CFA_same_value 0x08 |
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#define DW_CFA_register 0x09 |
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#define DW_CFA_remember_state 0x0a |
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#define DW_CFA_restore_state 0x0b |
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#define DW_CFA_def_cfa 0x0c |
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#define DW_CFA_def_cfa_register 0x0d |
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#define DW_CFA_def_cfa_offset 0x0e |
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#define DW_CFA_def_cfa_expression 0x0f |
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#define DW_CFA_expression 0x10 |
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#define DW_CFA_offset_extended_sf 0x11 |
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#define DW_CFA_def_cfa_sf 0x12 |
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#define DW_CFA_def_cfa_offset_sf 0x13 |
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#define DW_CFA_val_offset 0x14 |
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#define DW_CFA_val_offset_sf 0x15 |
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#define DW_CFA_val_expression 0x16 |
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#define DW_CFA_lo_user 0x1c |
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#define DW_CFA_GNU_window_save 0x2d |
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#define DW_CFA_GNU_args_size 0x2e |
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#define DW_CFA_GNU_negative_offset_extended 0x2f |
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#define DW_CFA_hi_user 0x3f |
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|
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#define DW_EH_PE_FORM 0x07 |
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#define DW_EH_PE_native 0x00 |
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#define DW_EH_PE_leb128 0x01 |
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#define DW_EH_PE_data2 0x02 |
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#define DW_EH_PE_data4 0x03 |
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#define DW_EH_PE_data8 0x04 |
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#define DW_EH_PE_signed 0x08 |
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#define DW_EH_PE_ADJUST 0x70 |
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#define DW_EH_PE_abs 0x00 |
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#define DW_EH_PE_pcrel 0x10 |
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#define DW_EH_PE_textrel 0x20 |
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#define DW_EH_PE_datarel 0x30 |
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#define DW_EH_PE_funcrel 0x40 |
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#define DW_EH_PE_aligned 0x50 |
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#define DW_EH_PE_indirect 0x80 |
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#define DW_EH_PE_omit 0xff |
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|
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#define CIE_ID 0 |
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|
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typedef unsigned long uleb128_t; |
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typedef signed long sleb128_t; |
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|
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static struct unwind_table { |
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struct { |
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unsigned long pc; |
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unsigned long range; |
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} core, init; |
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const void *address; |
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unsigned long size; |
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const unsigned char *header; |
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unsigned long hdrsz; |
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struct unwind_table *link; |
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const char *name; |
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} root_table; |
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|
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struct unwind_item { |
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enum item_location { |
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Nowhere, |
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Memory, |
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Register, |
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Value |
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} where; |
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uleb128_t value; |
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}; |
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|
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struct unwind_state { |
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uleb128_t loc, org; |
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const u8 *cieStart, *cieEnd; |
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uleb128_t codeAlign; |
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sleb128_t dataAlign; |
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struct cfa { |
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uleb128_t reg, offs; |
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} cfa; |
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struct unwind_item regs[ARRAY_SIZE(reg_info)]; |
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unsigned stackDepth:8; |
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unsigned version:8; |
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const u8 *label; |
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const u8 *stack[MAX_STACK_DEPTH]; |
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}; |
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|
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static const struct cfa badCFA = { ARRAY_SIZE(reg_info), 1 }; |
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|
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static struct unwind_table *find_table(unsigned long pc) |
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{ |
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struct unwind_table *table; |
|
|
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for (table = &root_table; table; table = table->link) |
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if ((pc >= table->core.pc |
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&& pc < table->core.pc + table->core.range) |
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|| (pc >= table->init.pc |
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&& pc < table->init.pc + table->init.range)) |
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break; |
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|
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return table; |
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} |
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|
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static unsigned long read_pointer(const u8 **pLoc, |
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const void *end, signed ptrType); |
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static void init_unwind_hdr(struct unwind_table *table, |
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void *(*alloc) (unsigned long)); |
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|
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/* |
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* wrappers for header alloc (vs. calling one vs. other at call site) |
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* to elide section mismatches warnings |
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*/ |
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static void *__init unw_hdr_alloc_early(unsigned long sz) |
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{ |
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return memblock_alloc_from(sz, sizeof(unsigned int), MAX_DMA_ADDRESS); |
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} |
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|
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static void init_unwind_table(struct unwind_table *table, const char *name, |
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const void *core_start, unsigned long core_size, |
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const void *init_start, unsigned long init_size, |
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const void *table_start, unsigned long table_size, |
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const u8 *header_start, unsigned long header_size) |
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{ |
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table->core.pc = (unsigned long)core_start; |
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table->core.range = core_size; |
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table->init.pc = (unsigned long)init_start; |
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table->init.range = init_size; |
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table->address = table_start; |
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table->size = table_size; |
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/* To avoid the pointer addition with NULL pointer.*/ |
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if (header_start != NULL) { |
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const u8 *ptr = header_start + 4; |
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const u8 *end = header_start + header_size; |
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/* See if the linker provided table looks valid. */ |
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if (header_size <= 4 |
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|| header_start[0] != 1 |
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|| (void *)read_pointer(&ptr, end, header_start[1]) |
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!= table_start |
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|| header_start[2] == DW_EH_PE_omit |
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|| read_pointer(&ptr, end, header_start[2]) <= 0 |
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|| header_start[3] == DW_EH_PE_omit) |
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header_start = NULL; |
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} |
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table->hdrsz = header_size; |
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smp_wmb(); |
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table->header = header_start; |
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table->link = NULL; |
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table->name = name; |
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} |
|
|
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void __init arc_unwind_init(void) |
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{ |
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init_unwind_table(&root_table, "kernel", _text, _end - _text, NULL, 0, |
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__start_unwind, __end_unwind - __start_unwind, |
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NULL, 0); |
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/*__start_unwind_hdr, __end_unwind_hdr - __start_unwind_hdr);*/ |
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|
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init_unwind_hdr(&root_table, unw_hdr_alloc_early); |
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} |
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|
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static const u32 bad_cie, not_fde; |
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static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *); |
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static const u32 *__cie_for_fde(const u32 *fde); |
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static signed fde_pointer_type(const u32 *cie); |
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|
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struct eh_frame_hdr_table_entry { |
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unsigned long start, fde; |
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}; |
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|
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static int cmp_eh_frame_hdr_table_entries(const void *p1, const void *p2) |
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{ |
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const struct eh_frame_hdr_table_entry *e1 = p1; |
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const struct eh_frame_hdr_table_entry *e2 = p2; |
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|
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return (e1->start > e2->start) - (e1->start < e2->start); |
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} |
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|
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static void swap_eh_frame_hdr_table_entries(void *p1, void *p2, int size) |
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{ |
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struct eh_frame_hdr_table_entry *e1 = p1; |
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struct eh_frame_hdr_table_entry *e2 = p2; |
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unsigned long v; |
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|
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v = e1->start; |
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e1->start = e2->start; |
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e2->start = v; |
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v = e1->fde; |
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e1->fde = e2->fde; |
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e2->fde = v; |
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} |
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|
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static void init_unwind_hdr(struct unwind_table *table, |
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void *(*alloc) (unsigned long)) |
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{ |
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const u8 *ptr; |
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unsigned long tableSize = table->size, hdrSize; |
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unsigned n; |
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const u32 *fde; |
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struct { |
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u8 version; |
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u8 eh_frame_ptr_enc; |
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u8 fde_count_enc; |
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u8 table_enc; |
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unsigned long eh_frame_ptr; |
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unsigned int fde_count; |
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struct eh_frame_hdr_table_entry table[]; |
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} __attribute__ ((__packed__)) *header; |
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|
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if (table->header) |
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return; |
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|
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if (table->hdrsz) |
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pr_warn(".eh_frame_hdr for '%s' present but unusable\n", |
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table->name); |
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|
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if (tableSize & (sizeof(*fde) - 1)) |
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return; |
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|
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for (fde = table->address, n = 0; |
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tableSize > sizeof(*fde) && tableSize - sizeof(*fde) >= *fde; |
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tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) { |
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const u32 *cie = cie_for_fde(fde, table); |
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signed ptrType; |
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|
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if (cie == ¬_fde) |
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continue; |
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if (cie == NULL || cie == &bad_cie) |
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goto ret_err; |
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ptrType = fde_pointer_type(cie); |
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if (ptrType < 0) |
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goto ret_err; |
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|
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ptr = (const u8 *)(fde + 2); |
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if (!read_pointer(&ptr, (const u8 *)(fde + 1) + *fde, |
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ptrType)) { |
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/* FIXME_Rajesh We have 4 instances of null addresses |
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* instead of the initial loc addr |
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* return; |
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*/ |
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WARN(1, "unwinder: FDE->initial_location NULL %p\n", |
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(const u8 *)(fde + 1) + *fde); |
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} |
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++n; |
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} |
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|
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if (tableSize || !n) |
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goto ret_err; |
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|
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hdrSize = 4 + sizeof(unsigned long) + sizeof(unsigned int) |
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+ 2 * n * sizeof(unsigned long); |
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|
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header = alloc(hdrSize); |
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if (!header) |
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goto ret_err; |
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|
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header->version = 1; |
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header->eh_frame_ptr_enc = DW_EH_PE_abs | DW_EH_PE_native; |
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header->fde_count_enc = DW_EH_PE_abs | DW_EH_PE_data4; |
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header->table_enc = DW_EH_PE_abs | DW_EH_PE_native; |
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put_unaligned((unsigned long)table->address, &header->eh_frame_ptr); |
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BUILD_BUG_ON(offsetof(typeof(*header), fde_count) |
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% __alignof(typeof(header->fde_count))); |
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header->fde_count = n; |
|
|
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BUILD_BUG_ON(offsetof(typeof(*header), table) |
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% __alignof(typeof(*header->table))); |
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for (fde = table->address, tableSize = table->size, n = 0; |
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tableSize; |
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tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) { |
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const u32 *cie = __cie_for_fde(fde); |
|
|
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if (fde[1] == CIE_ID) |
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continue; /* this is a CIE */ |
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ptr = (const u8 *)(fde + 2); |
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header->table[n].start = read_pointer(&ptr, |
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(const u8 *)(fde + 1) + |
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*fde, |
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fde_pointer_type(cie)); |
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header->table[n].fde = (unsigned long)fde; |
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++n; |
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} |
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WARN_ON(n != header->fde_count); |
|
|
|
sort(header->table, |
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n, |
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sizeof(*header->table), |
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cmp_eh_frame_hdr_table_entries, swap_eh_frame_hdr_table_entries); |
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|
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table->hdrsz = hdrSize; |
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smp_wmb(); |
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table->header = (const void *)header; |
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return; |
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|
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ret_err: |
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panic("Attention !!! Dwarf FDE parsing errors\n"); |
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} |
|
|
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#ifdef CONFIG_MODULES |
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static void *unw_hdr_alloc(unsigned long sz) |
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{ |
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return kmalloc(sz, GFP_KERNEL); |
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} |
|
|
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static struct unwind_table *last_table; |
|
|
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/* Must be called with module_mutex held. */ |
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void *unwind_add_table(struct module *module, const void *table_start, |
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unsigned long table_size) |
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{ |
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struct unwind_table *table; |
|
|
|
if (table_size <= 0) |
|
return NULL; |
|
|
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table = kmalloc(sizeof(*table), GFP_KERNEL); |
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if (!table) |
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return NULL; |
|
|
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init_unwind_table(table, module->name, |
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module->core_layout.base, module->core_layout.size, |
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module->init_layout.base, module->init_layout.size, |
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table_start, table_size, |
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NULL, 0); |
|
|
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init_unwind_hdr(table, unw_hdr_alloc); |
|
|
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#ifdef UNWIND_DEBUG |
|
unw_debug("Table added for [%s] %lx %lx\n", |
|
module->name, table->core.pc, table->core.range); |
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#endif |
|
if (last_table) |
|
last_table->link = table; |
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else |
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root_table.link = table; |
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last_table = table; |
|
|
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return table; |
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} |
|
|
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struct unlink_table_info { |
|
struct unwind_table *table; |
|
int init_only; |
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}; |
|
|
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static int unlink_table(void *arg) |
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{ |
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struct unlink_table_info *info = arg; |
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struct unwind_table *table = info->table, *prev; |
|
|
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for (prev = &root_table; prev->link && prev->link != table; |
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prev = prev->link) |
|
; |
|
|
|
if (prev->link) { |
|
if (info->init_only) { |
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table->init.pc = 0; |
|
table->init.range = 0; |
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info->table = NULL; |
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} else { |
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prev->link = table->link; |
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if (!prev->link) |
|
last_table = prev; |
|
} |
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} else |
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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; |
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struct unlink_table_info info; |
|
|
|
if (!table || table == &root_table) |
|
return; |
|
|
|
if (init_only && table == last_table) { |
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table->init.pc = 0; |
|
table->init.range = 0; |
|
return; |
|
} |
|
|
|
info.table = table; |
|
info.init_only = init_only; |
|
|
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unlink_table(&info); /* XXX: SMP */ |
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kfree(table->header); |
|
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 u32 *cie; |
|
|
|
cie = fde + 1 - fde[1] / sizeof(*fde); |
|
|
|
return cie; |
|
} |
|
|
|
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] == CIE_ID) |
|
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 = __cie_for_fde(fde); |
|
|
|
if (*cie <= sizeof(*cie) + 4 || *cie >= fde[1] - sizeof(*fde) |
|
|| (*cie & (sizeof(*cie) - 1)) |
|
|| (cie[1] != CIE_ID)) |
|
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 |
|
fallthrough; |
|
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 (*++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); |
|
fallthrough; |
|
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); |
|
fallthrough; |
|
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_register: "); |
|
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("UNKNOWN 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; |
|
cie = NULL; |
|
} |
|
} else { |
|
fde = NULL; |
|
cie = NULL; |
|
} |
|
} |
|
} |
|
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 (*++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 alignment factor */ |
|
state.codeAlign = get_uleb128(&ptr, end); |
|
/* get data alignment 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 */ |
|
if (frame->call_frame |
|
&& !UNW_DEFAULT_RA(state.regs[retAddrReg], state.dataAlign)) |
|
frame->call_frame = 0; |
|
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);
|
|
|