1182 строки
31 KiB
C
1182 строки
31 KiB
C
/*
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* Copyright (C) 2002-2006 Novell, Inc.
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* Jan Beulich <jbeulich@novell.com>
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* This code is released under version 2 of the GNU GPL.
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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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#include <linux/unwind.h>
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#include <linux/module.h>
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#include <linux/bootmem.h>
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#include <linux/sort.h>
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#include <linux/stop_machine.h>
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#include <asm/sections.h>
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#include <asm/uaccess.h>
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#include <asm/unaligned.h>
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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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#define MAX_STACK_DEPTH 8
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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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% FIELD_SIZEOF(struct unwind_frame_info, f)) \
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+ offsetof(struct unwind_frame_info, f) \
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/ FIELD_SIZEOF(struct unwind_frame_info, f), \
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FIELD_SIZEOF(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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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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#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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#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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#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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typedef unsigned long uleb128_t;
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typedef signed long sleb128_t;
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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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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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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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static const struct cfa badCFA = { ARRAY_SIZE(reg_info), 1 };
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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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return table;
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}
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static unsigned long read_pointer(const u8 **pLoc,
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const void *end,
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signed ptrType);
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static void init_unwind_table(struct unwind_table *table,
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const char *name,
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const void *core_start,
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unsigned long core_size,
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const void *init_start,
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unsigned long init_size,
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const void *table_start,
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unsigned long table_size,
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const u8 *header_start,
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unsigned long header_size)
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{
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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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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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/* 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]) != 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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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 unwind_init(void)
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{
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init_unwind_table(&root_table, "kernel",
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_text, _end - _text,
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NULL, 0,
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__start_unwind, __end_unwind - __start_unwind,
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__start_unwind_hdr, __end_unwind_hdr - __start_unwind_hdr);
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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 signed fde_pointer_type(const u32 *cie);
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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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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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return (e1->start > e2->start) - (e1->start < e2->start);
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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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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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static void __init setup_unwind_table(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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if (table->header)
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return;
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if (table->hdrsz)
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printk(KERN_WARNING ".eh_frame_hdr for '%s' present but unusable\n",
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table->name);
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if (tableSize & (sizeof(*fde) - 1))
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return;
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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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if (cie == ¬_fde)
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continue;
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if (cie == NULL
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|| cie == &bad_cie
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|| (ptrType = fde_pointer_type(cie)) < 0)
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return;
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ptr = (const u8 *)(fde + 2);
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if (!read_pointer(&ptr,
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(const u8 *)(fde + 1) + *fde,
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ptrType))
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return;
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++n;
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}
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if (tableSize || !n)
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return;
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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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header = alloc(hdrSize);
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if (!header)
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return;
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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 = fde + 1 - fde[1] / sizeof(*fde);
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if (!fde[1])
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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) + *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);
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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,
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swap_eh_frame_hdr_table_entries);
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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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}
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static void *__init balloc(unsigned long sz)
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{
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return __alloc_bootmem_nopanic(sz,
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sizeof(unsigned int),
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__pa(MAX_DMA_ADDRESS));
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}
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void __init unwind_setup(void)
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{
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setup_unwind_table(&root_table, balloc);
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}
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#ifdef CONFIG_MODULES
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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,
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const void *table_start,
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unsigned long table_size)
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{
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struct unwind_table *table;
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if (table_size <= 0)
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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->module_core, module->core_size,
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module->module_init, module->init_size,
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table_start, table_size,
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NULL, 0);
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if (last_table)
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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
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{
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struct unwind_table *table;
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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; prev = prev->link)
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;
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if (prev->link) {
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if (info->init_only) {
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table->init.pc = 0;
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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)
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last_table = prev;
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}
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} else
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info->table = NULL;
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return 0;
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}
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/* Must be called with module_mutex held. */
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void unwind_remove_table(void *handle, int init_only)
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{
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struct unwind_table *table = handle;
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struct unlink_table_info info;
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if (!table || table == &root_table)
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return;
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if (init_only && table == last_table) {
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table->init.pc = 0;
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table->init.range = 0;
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return;
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}
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info.table = table;
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info.init_only = init_only;
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stop_machine_run(unlink_table, &info, NR_CPUS);
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if (info.table)
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kfree(table);
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}
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#endif /* CONFIG_MODULES */
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static uleb128_t get_uleb128(const u8 **pcur, const u8 *end)
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{
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const u8 *cur = *pcur;
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uleb128_t value;
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unsigned shift;
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for (shift = 0, value = 0; cur < end; shift += 7) {
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if (shift + 7 > 8 * sizeof(value)
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&& (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) {
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cur = end + 1;
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break;
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}
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value |= (uleb128_t)(*cur & 0x7f) << shift;
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if (!(*cur++ & 0x80))
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break;
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}
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*pcur = cur;
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return value;
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}
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static sleb128_t get_sleb128(const u8 **pcur, const u8 *end)
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{
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const u8 *cur = *pcur;
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sleb128_t value;
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unsigned shift;
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for (shift = 0, value = 0; cur < end; shift += 7) {
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if (shift + 7 > 8 * sizeof(value)
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&& (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) {
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cur = end + 1;
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break;
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}
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value |= (sleb128_t)(*cur & 0x7f) << shift;
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if (!(*cur & 0x80)) {
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value |= -(*cur++ & 0x40) << shift;
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break;
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}
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}
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*pcur = cur;
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return value;
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}
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static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *table)
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{
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const u32 *cie;
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if (!*fde || (*fde & (sizeof(*fde) - 1)))
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return &bad_cie;
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if (!fde[1])
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return ¬_fde; /* this is a CIE */
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if ((fde[1] & (sizeof(*fde) - 1))
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|| fde[1] > (unsigned long)(fde + 1) - (unsigned long)table->address)
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return NULL; /* this is not a valid FDE */
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cie = fde + 1 - fde[1] / sizeof(*fde);
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if (*cie <= sizeof(*cie) + 4
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|| *cie >= fde[1] - sizeof(*fde)
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|| (*cie & (sizeof(*cie) - 1))
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|| cie[1])
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return NULL; /* this is not a (valid) CIE */
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return cie;
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}
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static unsigned long read_pointer(const u8 **pLoc,
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const void *end,
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signed ptrType)
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{
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unsigned long value = 0;
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union {
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const u8 *p8;
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const u16 *p16u;
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const s16 *p16s;
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const u32 *p32u;
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const s32 *p32s;
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const unsigned long *pul;
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} ptr;
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if (ptrType < 0 || ptrType == DW_EH_PE_omit)
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return 0;
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ptr.p8 = *pLoc;
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switch(ptrType & DW_EH_PE_FORM) {
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case DW_EH_PE_data2:
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if (end < (const void *)(ptr.p16u + 1))
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return 0;
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if(ptrType & DW_EH_PE_signed)
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value = get_unaligned(ptr.p16s++);
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else
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value = get_unaligned(ptr.p16u++);
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break;
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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(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 *)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 */
|
|
if ((ptr = memchr(aug = (const void *)ptr, 0, end - 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;
|
|
|
|
return delta > 0;
|
|
}
|
|
|
|
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;
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
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:
|
|
switch(*ptr.p8++) {
|
|
case DW_CFA_nop:
|
|
break;
|
|
case DW_CFA_set_loc:
|
|
if ((state->loc = read_pointer(&ptr.p8, end, ptrType)) == 0)
|
|
result = 0;
|
|
break;
|
|
case DW_CFA_advance_loc1:
|
|
result = ptr.p8 < end && advance_loc(*ptr.p8++, state);
|
|
break;
|
|
case DW_CFA_advance_loc2:
|
|
result = ptr.p8 <= end + 2
|
|
&& advance_loc(*ptr.p16++, state);
|
|
break;
|
|
case DW_CFA_advance_loc4:
|
|
result = ptr.p8 <= end + 4
|
|
&& advance_loc(*ptr.p32++, state);
|
|
break;
|
|
case DW_CFA_offset_extended:
|
|
value = get_uleb128(&ptr.p8, end);
|
|
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:
|
|
case DW_CFA_undefined:
|
|
case DW_CFA_same_value:
|
|
set_rule(get_uleb128(&ptr.p8, end), Nowhere, 0, state);
|
|
break;
|
|
case DW_CFA_register:
|
|
value = get_uleb128(&ptr.p8, end);
|
|
set_rule(value,
|
|
Register,
|
|
get_uleb128(&ptr.p8, end), state);
|
|
break;
|
|
case DW_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:
|
|
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);
|
|
/*nobreak*/
|
|
case DW_CFA_def_cfa_offset:
|
|
state->cfa.offs = get_uleb128(&ptr.p8, end);
|
|
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:
|
|
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:
|
|
result = 0;
|
|
break;
|
|
}
|
|
break;
|
|
case 1:
|
|
result = advance_loc(*ptr.p8++ & 0x3f, state);
|
|
break;
|
|
case 2:
|
|
value = *ptr.p8++ & 0x3f;
|
|
set_rule(value, Memory, get_uleb128(&ptr.p8, end), state);
|
|
break;
|
|
case 3:
|
|
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 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;
|
|
|
|
if (UNW_PC(frame) == 0)
|
|
return -EINVAL;
|
|
if ((table = find_table(pc)) != 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 (and thus present) */
|
|
if (*ptr == 'z') {
|
|
while (++ptr < end && *ptr) {
|
|
switch(*ptr) {
|
|
/* check 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);
|
|
/* skip augmentation */
|
|
if (((const char *)(cie + 2))[1] == 'z')
|
|
ptr += get_uleb128(&ptr, end);
|
|
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;
|
|
#endif
|
|
|
|
#ifdef CONFIG_FRAME_POINTER
|
|
top = STACK_TOP(frame->task);
|
|
bottom = STACK_BOTTOM(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));
|
|
/* process instructions */
|
|
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;
|
|
/* 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((unsigned long)UNW_SP(frame), cfa);
|
|
endLoc = max((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);
|
|
}
|
|
#ifndef CONFIG_64BIT
|
|
# define CASES CASE(8); CASE(16); CASE(32)
|
|
#else
|
|
# define CASES CASE(8); CASE(16); CASE(32); CASE(64)
|
|
#endif
|
|
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) {
|
|
#define CASE(n) \
|
|
case sizeof(u##n): \
|
|
state.regs[i].value = FRAME_REG(state.regs[i].value, \
|
|
const u##n); \
|
|
break
|
|
CASES;
|
|
#undef CASE
|
|
default:
|
|
return -EIO;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
|
|
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) {
|
|
#define CASE(n) case sizeof(u##n): \
|
|
FRAME_REG(i, u##n) = state.regs[i].value; \
|
|
break
|
|
CASES;
|
|
#undef CASE
|
|
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: {
|
|
unsigned long 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) {
|
|
#define CASE(n) case sizeof(u##n): \
|
|
__get_user(FRAME_REG(i, u##n), (u##n *)addr); \
|
|
break
|
|
CASES;
|
|
#undef CASE
|
|
default:
|
|
return -EIO;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
#undef CASES
|
|
#undef FRAME_REG
|
|
}
|
|
EXPORT_SYMBOL(unwind);
|
|
|
|
int unwind_init_frame_info(struct unwind_frame_info *info,
|
|
struct task_struct *tsk,
|
|
/*const*/ struct pt_regs *regs)
|
|
{
|
|
info->task = tsk;
|
|
info->call_frame = 0;
|
|
arch_unw_init_frame_info(info, regs);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(unwind_init_frame_info);
|
|
|
|
/*
|
|
* Prepare to unwind a blocked task.
|
|
*/
|
|
int unwind_init_blocked(struct unwind_frame_info *info,
|
|
struct task_struct *tsk)
|
|
{
|
|
info->task = tsk;
|
|
info->call_frame = 0;
|
|
arch_unw_init_blocked(info);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(unwind_init_blocked);
|
|
|
|
/*
|
|
* Prepare to unwind the currently running thread.
|
|
*/
|
|
int unwind_init_running(struct unwind_frame_info *info,
|
|
asmlinkage int (*callback)(struct unwind_frame_info *,
|
|
void *arg),
|
|
void *arg)
|
|
{
|
|
info->task = current;
|
|
info->call_frame = 0;
|
|
|
|
return arch_unwind_init_running(info, callback, arg);
|
|
}
|
|
EXPORT_SYMBOL(unwind_init_running);
|
|
|
|
/*
|
|
* Unwind until the return pointer is in user-land (or until an error
|
|
* occurs). Returns 0 if successful, negative number in case of
|
|
* error.
|
|
*/
|
|
int unwind_to_user(struct unwind_frame_info *info)
|
|
{
|
|
while (!arch_unw_user_mode(info)) {
|
|
int err = unwind(info);
|
|
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(unwind_to_user);
|