// SPDX-License-Identifier: GPL-2.0/* * Copyright (C) 2009 Matt Fleming <matt@console-pimps.org> * * This is an implementation of a DWARF unwinder. Its main purpose is * for generating stacktrace information. Based on the DWARF 3 * specification from http://www.dwarfstd.org. * * TODO: * - DWARF64 doesn't work. * - Registers with DWARF_VAL_OFFSET rules aren't handled properly. */ /* #define DEBUG */#include <linux/kernel.h>#include <linux/io.h>#include <linux/list.h>#include <linux/mempool.h>#include <linux/mm.h>#include <linux/elf.h>#include <linux/ftrace.h>#include <linux/module.h>#include <linux/slab.h>#include <asm/dwarf.h>#include <asm/unwinder.h>#include <asm/sections.h>#include <linux/unaligned.h>#include <asm/stacktrace.h> /* Reserve enough memory for two stack frames */#define DWARF_FRAME_MIN_REQ 2/* ... with 4 registers per frame. */#define DWARF_REG_MIN_REQ (DWARF_FRAME_MIN_REQ * 4) static struct kmem_cache *dwarf_frame_cachep;static mempool_t *dwarf_frame_pool; static struct kmem_cache *dwarf_reg_cachep;static mempool_t *dwarf_reg_pool; static struct rb_root cie_root;static DEFINE_SPINLOCK(dwarf_cie_lock); static struct rb_root fde_root;static DEFINE_SPINLOCK(dwarf_fde_lock); static struct dwarf_cie *cached_cie; static unsigned int dwarf_unwinder_ready; /** * dwarf_frame_alloc_reg - allocate memory for a DWARF register * @frame: the DWARF frame whose list of registers we insert on * @reg_num: the register number * * Allocate space for, and initialise, a dwarf reg from * dwarf_reg_pool and insert it onto the (unsorted) linked-list of * dwarf registers for @frame. * * Return the initialised DWARF reg. */static struct dwarf_reg *dwarf_frame_alloc_reg(struct dwarf_frame *frame, unsigned int reg_num){ struct dwarf_reg *reg; reg = mempool_alloc(dwarf_reg_pool, GFP_ATOMIC); if (!reg) { printk(KERN_WARNING "Unable to allocate a DWARF register\n"); /* * Let's just bomb hard here, we have no way to * gracefully recover. */ UNWINDER_BUG(); } reg->number = reg_num; reg->addr = 0; reg->flags = 0; list_add(®->link, &frame->reg_list); return reg;} static void dwarf_frame_free_regs(struct dwarf_frame *frame){ struct dwarf_reg *reg, *n; list_for_each_entry_safe(reg, n, &frame->reg_list, link) { list_del(®->link); mempool_free(reg, dwarf_reg_pool); }} /** * dwarf_frame_reg - return a DWARF register * @frame: the DWARF frame to search in for @reg_num * @reg_num: the register number to search for * * Lookup and return the dwarf reg @reg_num for this frame. Return * NULL if @reg_num is an register invalid number. */static struct dwarf_reg *dwarf_frame_reg(struct dwarf_frame *frame, unsigned int reg_num){ struct dwarf_reg *reg; list_for_each_entry(reg, &frame->reg_list, link) { if (reg->number == reg_num) return reg; } return NULL;} /** * dwarf_read_addr - read dwarf data * @src: source address of data * @dst: destination address to store the data to * * Read 'n' bytes from @src, where 'n' is the size of an address on * the native machine. We return the number of bytes read, which * should always be 'n'. We also have to be careful when reading * from @src and writing to @dst, because they can be arbitrarily * aligned. Return 'n' - the number of bytes read. */static inline int dwarf_read_addr(unsigned long *src, unsigned long *dst){ u32 val = get_unaligned(src); put_unaligned(val, dst); return sizeof(unsigned long *);} /** * dwarf_read_uleb128 - read unsigned LEB128 data * @addr: the address where the ULEB128 data is stored * @ret: address to store the result * * Decode an unsigned LEB128 encoded datum. The algorithm is taken * from Appendix C of the DWARF 3 spec. For information on the * encodings refer to section "7.6 - Variable Length Data". Return * the number of bytes read. */static inline unsigned long dwarf_read_uleb128(char *addr, unsigned int *ret){ unsigned int result; unsigned char byte; int shift, count; result = 0; shift = 0; count = 0; while (1) { byte = __raw_readb(addr); addr++; count++; result |= (byte & 0x7f) << shift; shift += 7; if (!(byte & 0x80)) break; } *ret = result; return count;} /** * dwarf_read_leb128 - read signed LEB128 data * @addr: the address of the LEB128 encoded data * @ret: address to store the result * * Decode signed LEB128 data. The algorithm is taken from Appendix * C of the DWARF 3 spec. Return the number of bytes read. */static inline unsigned long dwarf_read_leb128(char *addr, int *ret){ unsigned char byte; int result, shift; int num_bits; int count; result = 0; shift = 0; count = 0; while (1) { byte = __raw_readb(addr); addr++; result |= (byte & 0x7f) << shift; shift += 7; count++; if (!(byte & 0x80)) break; } /* The number of bits in a signed integer. */ num_bits = 8 * sizeof(result); if ((shift < num_bits) && (byte & 0x40)) result |= (-1 << shift); *ret = result; return count;} /** * dwarf_read_encoded_value - return the decoded value at @addr * @addr: the address of the encoded value * @val: where to write the decoded value * @encoding: the encoding with which we can decode @addr * * GCC emits encoded address in the .eh_frame FDE entries. Decode * the value at @addr using @encoding. The decoded value is written * to @val and the number of bytes read is returned. */static int dwarf_read_encoded_value(char *addr, unsigned long *val, char encoding){ unsigned long decoded_addr = 0; int count = 0; switch (encoding & 0x70) { case DW_EH_PE_absptr: break; case DW_EH_PE_pcrel: decoded_addr = (unsigned long)addr; break; default: pr_debug("encoding=0x%x\n", (encoding & 0x70)); UNWINDER_BUG(); } if ((encoding & 0x07) == 0x00) encoding |= DW_EH_PE_udata4; switch (encoding & 0x0f) { case DW_EH_PE_sdata4: case DW_EH_PE_udata4: count += 4; decoded_addr += get_unaligned((u32 *)addr); __raw_writel(decoded_addr, val); break; default: pr_debug("encoding=0x%x\n", encoding); UNWINDER_BUG(); } return count;} /** * dwarf_entry_len - return the length of an FDE or CIE * @addr: the address of the entry * @len: the length of the entry * * Read the initial_length field of the entry and store the size of * the entry in @len. We return the number of bytes read. Return a * count of 0 on error. */static inline int dwarf_entry_len(char *addr, unsigned long *len){ u32 initial_len; int count; initial_len = get_unaligned((u32 *)addr); count = 4; /* * An initial length field value in the range DW_LEN_EXT_LO - * DW_LEN_EXT_HI indicates an extension, and should not be * interpreted as a length. The only extension that we currently * understand is the use of DWARF64 addresses. */ if (initial_len >= DW_EXT_LO && initial_len <= DW_EXT_HI) { /* * The 64-bit length field immediately follows the * compulsory 32-bit length field. */ if (initial_len == DW_EXT_DWARF64) { *len = get_unaligned((u64 *)addr + 4); count = 12; } else { printk(KERN_WARNING "Unknown DWARF extension\n"); count = 0; } } else *len = initial_len; return count;} /** * dwarf_lookup_cie - locate the cie * @cie_ptr: pointer to help with lookup */static struct dwarf_cie *dwarf_lookup_cie(unsigned long cie_ptr){ struct rb_node **rb_node = &cie_root.rb_node; struct dwarf_cie *cie = NULL; unsigned long flags; spin_lock_irqsave(&dwarf_cie_lock, flags); /* * We've cached the last CIE we looked up because chances are * that the FDE wants this CIE. */ if (cached_cie && cached_cie->cie_pointer == cie_ptr) { cie = cached_cie; goto out; } while (*rb_node) { struct dwarf_cie *cie_tmp; cie_tmp = rb_entry(*rb_node, struct dwarf_cie, node); BUG_ON(!cie_tmp); if (cie_ptr == cie_tmp->cie_pointer) { cie = cie_tmp; cached_cie = cie_tmp; goto out; } else { if (cie_ptr < cie_tmp->cie_pointer) rb_node = &(*rb_node)->rb_left; else rb_node = &(*rb_node)->rb_right; } } out: spin_unlock_irqrestore(&dwarf_cie_lock, flags); return cie;} /** * dwarf_lookup_fde - locate the FDE that covers pc * @pc: the program counter */static struct dwarf_fde *dwarf_lookup_fde(unsigned long pc){ struct rb_node **rb_node = &fde_root.rb_node; struct dwarf_fde *fde = NULL; unsigned long flags; spin_lock_irqsave(&dwarf_fde_lock, flags); while (*rb_node) { struct dwarf_fde *fde_tmp; unsigned long tmp_start, tmp_end; fde_tmp = rb_entry(*rb_node, struct dwarf_fde, node); BUG_ON(!fde_tmp); tmp_start = fde_tmp->initial_location; tmp_end = fde_tmp->initial_location + fde_tmp->address_range; if (pc < tmp_start) { rb_node = &(*rb_node)->rb_left; } else { if (pc < tmp_end) { fde = fde_tmp; goto out; } else rb_node = &(*rb_node)->rb_right; } } out: spin_unlock_irqrestore(&dwarf_fde_lock, flags); return fde;} /** * dwarf_cfa_execute_insns - execute instructions to calculate a CFA * @insn_start: address of the first instruction * @insn_end: address of the last instruction * @cie: the CIE for this function * @fde: the FDE for this function * @frame: the instructions calculate the CFA for this frame * @pc: the program counter of the address we're interested in * * Execute the Call Frame instruction sequence starting at * @insn_start and ending at @insn_end. The instructions describe * how to calculate the Canonical Frame Address of a stackframe. * Store the results in @frame. */static int dwarf_cfa_execute_insns(unsigned char *insn_start, unsigned char *insn_end, struct dwarf_cie *cie, struct dwarf_fde *fde, struct dwarf_frame *frame, unsigned long pc){ unsigned char insn; unsigned char *current_insn; unsigned int count, delta, reg, expr_len, offset; struct dwarf_reg *regp; current_insn = insn_start; while (current_insn < insn_end && frame->pc <= pc) { insn = __raw_readb(current_insn++); /* * Firstly, handle the opcodes that embed their operands * in the instructions. */ switch (DW_CFA_opcode(insn)) { case DW_CFA_advance_loc: delta = DW_CFA_operand(insn); delta *= cie->code_alignment_factor; frame->pc += delta; continue; /* NOTREACHED */ case DW_CFA_offset: reg = DW_CFA_operand(insn); count = dwarf_read_uleb128(current_insn, &offset); current_insn += count; offset *= cie->data_alignment_factor; regp = dwarf_frame_alloc_reg(frame, reg); regp->addr = offset; regp->flags |= DWARF_REG_OFFSET; continue; /* NOTREACHED */ case DW_CFA_restore: reg = DW_CFA_operand(insn); continue; /* NOTREACHED */ } /* * Secondly, handle the opcodes that don't embed their * operands in the instruction. */ switch (insn) { case DW_CFA_nop: continue; case DW_CFA_advance_loc1: delta = *current_insn++; frame->pc += delta * cie->code_alignment_factor; break; case DW_CFA_advance_loc2: delta = get_unaligned((u16 *)current_insn); current_insn += 2; frame->pc += delta * cie->code_alignment_factor; break; case DW_CFA_advance_loc4: delta = get_unaligned((u32 *)current_insn); current_insn += 4; frame->pc += delta * cie->code_alignment_factor; break; case DW_CFA_offset_extended: count = dwarf_read_uleb128(current_insn, ®); current_insn += count; count = dwarf_read_uleb128(current_insn, &offset); current_insn += count; offset *= cie->data_alignment_factor; break; case DW_CFA_restore_extended: count = dwarf_read_uleb128(current_insn, ®); current_insn += count; break; case DW_CFA_undefined: count = dwarf_read_uleb128(current_insn, ®); current_insn += count; regp = dwarf_frame_alloc_reg(frame, reg); regp->flags |= DWARF_UNDEFINED; break; case DW_CFA_def_cfa: count = dwarf_read_uleb128(current_insn, &frame->cfa_register); current_insn += count; count = dwarf_read_uleb128(current_insn, &frame->cfa_offset); current_insn += count; frame->flags |= DWARF_FRAME_CFA_REG_OFFSET; break; case DW_CFA_def_cfa_register: count = dwarf_read_uleb128(current_insn, &frame->cfa_register); current_insn += count; frame->flags |= DWARF_FRAME_CFA_REG_OFFSET; break; case DW_CFA_def_cfa_offset: count = dwarf_read_uleb128(current_insn, &offset); current_insn += count; frame->cfa_offset = offset; break; case DW_CFA_def_cfa_expression: count = dwarf_read_uleb128(current_insn, &expr_len);Lines 1–500 of 1206. 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// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2009 Matt Fleming <matt@console-pimps.org> * * This is an implementation of a DWARF unwinder. Its main purpose is * for generating stacktrace information. Based on the DWARF 3 * specification from http://www.dwarfstd.org. * * TODO: * - DWARF64 doesn't work. * - Registers with DWARF_VAL_OFFSET rules aren't handled properly. */ /* #define DEBUG */ #include <linux/kernel.h> #include <linux/io.h> #include <linux/list.h> #include <linux/mempool.h> #include <linux/mm.h> #include <linux/elf.h> #include <linux/ftrace.h> #include <linux/module.h> #include <linux/slab.h> #include <asm/dwarf.h> #include <asm/unwinder.h> #include <asm/sections.h> #include <linux/unaligned.h> #include <asm/stacktrace.h> /* Reserve enough memory for two stack frames */ #define DWARF_FRAME_MIN_REQ 2 /* ... with 4 registers per frame. */ #define DWARF_REG_MIN_REQ (DWARF_FRAME_MIN_REQ * 4) static struct kmem_cache *dwarf_frame_cachep; static mempool_t *dwarf_frame_pool; static struct kmem_cache *dwarf_reg_cachep; static mempool_t *dwarf_reg_pool; static struct rb_root cie_root; static DEFINE_SPINLOCK(dwarf_cie_lock); static struct rb_root fde_root; static DEFINE_SPINLOCK(dwarf_fde_lock); static struct dwarf_cie *cached_cie; static unsigned int dwarf_unwinder_ready; /** * dwarf_frame_alloc_reg - allocate memory for a DWARF register * @frame: the DWARF frame whose list of registers we insert on * @reg_num: the register number * * Allocate space for, and initialise, a dwarf reg from * dwarf_reg_pool and insert it onto the (unsorted) linked-list of * dwarf registers for @frame. * * Return the initialised DWARF reg. */ static struct dwarf_reg *dwarf_frame_alloc_reg(struct dwarf_frame *frame, unsigned int reg_num) { struct dwarf_reg *reg; reg = mempool_alloc(dwarf_reg_pool, GFP_ATOMIC); if (!reg) { printk(KERN_WARNING "Unable to allocate a DWARF register\n"); /* * Let's just bomb hard here, we have no way to * gracefully recover. */ UNWINDER_BUG(); } reg->number = reg_num; reg->addr = 0; reg->flags = 0; list_add(®->link, &frame->reg_list); return reg; } static void dwarf_frame_free_regs(struct dwarf_frame *frame) { struct dwarf_reg *reg, *n; list_for_each_entry_safe(reg, n, &frame->reg_list, link) { list_del(®->link); mempool_free(reg, dwarf_reg_pool); } } /** * dwarf_frame_reg - return a DWARF register * @frame: the DWARF frame to search in for @reg_num * @reg_num: the register number to search for * * Lookup and return the dwarf reg @reg_num for this frame. Return * NULL if @reg_num is an register invalid number. */ static struct dwarf_reg *dwarf_frame_reg(struct dwarf_frame *frame, unsigned int reg_num) { struct dwarf_reg *reg; list_for_each_entry(reg, &frame->reg_list, link) { if (reg->number == reg_num) return reg; } return NULL; } /** * dwarf_read_addr - read dwarf data * @src: source address of data * @dst: destination address to store the data to * * Read 'n' bytes from @src, where 'n' is the size of an address on * the native machine. We return the number of bytes read, which * should always be 'n'. We also have to be careful when reading * from @src and writing to @dst, because they can be arbitrarily * aligned. Return 'n' - the number of bytes read. */ static inline int dwarf_read_addr(unsigned long *src, unsigned long *dst) { u32 val = get_unaligned(src); put_unaligned(val, dst); return sizeof(unsigned long *); } /** * dwarf_read_uleb128 - read unsigned LEB128 data * @addr: the address where the ULEB128 data is stored * @ret: address to store the result * * Decode an unsigned LEB128 encoded datum. The algorithm is taken * from Appendix C of the DWARF 3 spec. For information on the * encodings refer to section "7.6 - Variable Length Data". Return * the number of bytes read. */ static inline unsigned long dwarf_read_uleb128(char *addr, unsigned int *ret) { unsigned int result; unsigned char byte; int shift, count; result = 0; shift = 0; count = 0; while (1) { byte = __raw_readb(addr); addr++; count++; result |= (byte & 0x7f) << shift; shift += 7; if (!(byte & 0x80)) break; } *ret = result; return count; } /** * dwarf_read_leb128 - read signed LEB128 data * @addr: the address of the LEB128 encoded data * @ret: address to store the result * * Decode signed LEB128 data. The algorithm is taken from Appendix * C of the DWARF 3 spec. Return the number of bytes read. */ static inline unsigned long dwarf_read_leb128(char *addr, int *ret) { unsigned char byte; int result, shift; int num_bits; int count; result = 0; shift = 0; count = 0; while (1) { byte = __raw_readb(addr); addr++; result |= (byte & 0x7f) << shift; shift += 7; count++; if (!(byte & 0x80)) break; } /* The number of bits in a signed integer. */ num_bits = 8 * sizeof(result); if ((shift < num_bits) && (byte & 0x40)) result |= (-1 << shift); *ret = result; return count; } /** * dwarf_read_encoded_value - return the decoded value at @addr * @addr: the address of the encoded value * @val: where to write the decoded value * @encoding: the encoding with which we can decode @addr * * GCC emits encoded address in the .eh_frame FDE entries. Decode * the value at @addr using @encoding. The decoded value is written * to @val and the number of bytes read is returned. */ static int dwarf_read_encoded_value(char *addr, unsigned long *val, char encoding) { unsigned long decoded_addr = 0; int count = 0; switch (encoding & 0x70) { case DW_EH_PE_absptr: break; case DW_EH_PE_pcrel: decoded_addr = (unsigned long)addr; break; default: pr_debug("encoding=0x%x\n", (encoding & 0x70)); UNWINDER_BUG(); } if ((encoding & 0x07) == 0x00) encoding |= DW_EH_PE_udata4; switch (encoding & 0x0f) { case DW_EH_PE_sdata4: case DW_EH_PE_udata4: count += 4; decoded_addr += get_unaligned((u32 *)addr); __raw_writel(decoded_addr, val); break; default: pr_debug("encoding=0x%x\n", encoding); UNWINDER_BUG(); } return count; } /** * dwarf_entry_len - return the length of an FDE or CIE * @addr: the address of the entry * @len: the length of the entry * * Read the initial_length field of the entry and store the size of * the entry in @len. We return the number of bytes read. Return a * count of 0 on error. */ static inline int dwarf_entry_len(char *addr, unsigned long *len) { u32 initial_len; int count; initial_len = get_unaligned((u32 *)addr); count = 4; /* * An initial length field value in the range DW_LEN_EXT_LO - * DW_LEN_EXT_HI indicates an extension, and should not be * interpreted as a length. The only extension that we currently * understand is the use of DWARF64 addresses. */ if (initial_len >= DW_EXT_LO && initial_len <= DW_EXT_HI) { /* * The 64-bit length field immediately follows the * compulsory 32-bit length field. */ if (initial_len == DW_EXT_DWARF64) { *len = get_unaligned((u64 *)addr + 4); count = 12; } else { printk(KERN_WARNING "Unknown DWARF extension\n"); count = 0; } } else *len = initial_len; return count; } /** * dwarf_lookup_cie - locate the cie * @cie_ptr: pointer to help with lookup */ static struct dwarf_cie *dwarf_lookup_cie(unsigned long cie_ptr) { struct rb_node **rb_node = &cie_root.rb_node; struct dwarf_cie *cie = NULL; unsigned long flags; spin_lock_irqsave(&dwarf_cie_lock, flags); /* * We've cached the last CIE we looked up because chances are * that the FDE wants this CIE. */ if (cached_cie && cached_cie->cie_pointer == cie_ptr) { cie = cached_cie; goto out; } while (*rb_node) { struct dwarf_cie *cie_tmp; cie_tmp = rb_entry(*rb_node, struct dwarf_cie, node); BUG_ON(!cie_tmp); if (cie_ptr == cie_tmp->cie_pointer) { cie = cie_tmp; cached_cie = cie_tmp; goto out; } else { if (cie_ptr < cie_tmp->cie_pointer) rb_node = &(*rb_node)->rb_left; else rb_node = &(*rb_node)->rb_right; } } out: spin_unlock_irqrestore(&dwarf_cie_lock, flags); return cie; } /** * dwarf_lookup_fde - locate the FDE that covers pc * @pc: the program counter */ static struct dwarf_fde *dwarf_lookup_fde(unsigned long pc) { struct rb_node **rb_node = &fde_root.rb_node; struct dwarf_fde *fde = NULL; unsigned long flags; spin_lock_irqsave(&dwarf_fde_lock, flags); while (*rb_node) { struct dwarf_fde *fde_tmp; unsigned long tmp_start, tmp_end; fde_tmp = rb_entry(*rb_node, struct dwarf_fde, node); BUG_ON(!fde_tmp); tmp_start = fde_tmp->initial_location; tmp_end = fde_tmp->initial_location + fde_tmp->address_range; if (pc < tmp_start) { rb_node = &(*rb_node)->rb_left; } else { if (pc < tmp_end) { fde = fde_tmp; goto out; } else rb_node = &(*rb_node)->rb_right; } } out: spin_unlock_irqrestore(&dwarf_fde_lock, flags); return fde; } /** * dwarf_cfa_execute_insns - execute instructions to calculate a CFA * @insn_start: address of the first instruction * @insn_end: address of the last instruction * @cie: the CIE for this function * @fde: the FDE for this function * @frame: the instructions calculate the CFA for this frame * @pc: the program counter of the address we're interested in * * Execute the Call Frame instruction sequence starting at * @insn_start and ending at @insn_end. The instructions describe * how to calculate the Canonical Frame Address of a stackframe. * Store the results in @frame. */ static int dwarf_cfa_execute_insns(unsigned char *insn_start, unsigned char *insn_end, struct dwarf_cie *cie, struct dwarf_fde *fde, struct dwarf_frame *frame, unsigned long pc) { unsigned char insn; unsigned char *current_insn; unsigned int count, delta, reg, expr_len, offset; struct dwarf_reg *regp; current_insn = insn_start; while (current_insn < insn_end && frame->pc <= pc) { insn = __raw_readb(current_insn++); /* * Firstly, handle the opcodes that embed their operands * in the instructions. */ switch (DW_CFA_opcode(insn)) { case DW_CFA_advance_loc: delta = DW_CFA_operand(insn); delta *= cie->code_alignment_factor; frame->pc += delta; continue; /* NOTREACHED */ case DW_CFA_offset: reg = DW_CFA_operand(insn); count = dwarf_read_uleb128(current_insn, &offset); current_insn += count; offset *= cie->data_alignment_factor; regp = dwarf_frame_alloc_reg(frame, reg); regp->addr = offset; regp->flags |= DWARF_REG_OFFSET; continue; /* NOTREACHED */ case DW_CFA_restore: reg = DW_CFA_operand(insn); continue; /* NOTREACHED */ } /* * Secondly, handle the opcodes that don't embed their * operands in the instruction. */ switch (insn) { case DW_CFA_nop: continue; case DW_CFA_advance_loc1: delta = *current_insn++; frame->pc += delta * cie->code_alignment_factor; break; case DW_CFA_advance_loc2: delta = get_unaligned((u16 *)current_insn); current_insn += 2; frame->pc += delta * cie->code_alignment_factor; break; case DW_CFA_advance_loc4: delta = get_unaligned((u32 *)current_insn); current_insn += 4; frame->pc += delta * cie->code_alignment_factor; break; case DW_CFA_offset_extended: count = dwarf_read_uleb128(current_insn, ®); current_insn += count; count = dwarf_read_uleb128(current_insn, &offset); current_insn += count; offset *= cie->data_alignment_factor; break; case DW_CFA_restore_extended: count = dwarf_read_uleb128(current_insn, ®); current_insn += count; break; case DW_CFA_undefined: count = dwarf_read_uleb128(current_insn, ®); current_insn += count; regp = dwarf_frame_alloc_reg(frame, reg); regp->flags |= DWARF_UNDEFINED; break; case DW_CFA_def_cfa: count = dwarf_read_uleb128(current_insn, &frame->cfa_register); current_insn += count; count = dwarf_read_uleb128(current_insn, &frame->cfa_offset); current_insn += count; frame->flags |= DWARF_FRAME_CFA_REG_OFFSET; break; case DW_CFA_def_cfa_register: count = dwarf_read_uleb128(current_insn, &frame->cfa_register); current_insn += count; frame->flags |= DWARF_FRAME_CFA_REG_OFFSET; break; case DW_CFA_def_cfa_offset: count = dwarf_read_uleb128(current_insn, &offset); current_insn += count; frame->cfa_offset = offset; break; case DW_CFA_def_cfa_expression: count = dwarf_read_uleb128(current_insn, &expr_len);