/* * Copyright (C) 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) * Copyright (C) 2002-2006 Novell, Inc. * Jan Beulich * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * A simple API for unwinding kernel stacks. This is used for * debugging and error reporting purposes. The kernel doesn't need * full-blown stack unwinding with all the bells and whistles, so there * is not much point in implementing the full Dwarf2 unwind API. */ #include #include #include #include #include #include #include #include #include #include #include extern char __start_unwind[], __end_unwind[]; /* extern const u8 __start_unwind_hdr[], __end_unwind_hdr[];*/ /* #define UNWIND_DEBUG */ #ifdef UNWIND_DEBUG int dbg_unw; #define unw_debug(fmt, ...) \ do { \ if (dbg_unw) \ pr_info(fmt, ##__VA_ARGS__); \ } while (0); #else #define unw_debug(fmt, ...) #endif #define MAX_STACK_DEPTH 8 #define EXTRA_INFO(f) { \ BUILD_BUG_ON_ZERO(offsetof(struct unwind_frame_info, f) \ % FIELD_SIZEOF(struct unwind_frame_info, f)) \ + offsetof(struct unwind_frame_info, f) \ / FIELD_SIZEOF(struct unwind_frame_info, f), \ FIELD_SIZEOF(struct unwind_frame_info, f) \ } #define PTREGS_INFO(f) EXTRA_INFO(regs.f) static const struct { unsigned offs:BITS_PER_LONG / 2; unsigned width:BITS_PER_LONG / 2; } reg_info[] = { UNW_REGISTER_INFO}; #undef PTREGS_INFO #undef EXTRA_INFO #ifndef REG_INVALID #define REG_INVALID(r) (reg_info[r].width == 0) #endif #define DW_CFA_nop 0x00 #define DW_CFA_set_loc 0x01 #define DW_CFA_advance_loc1 0x02 #define DW_CFA_advance_loc2 0x03 #define DW_CFA_advance_loc4 0x04 #define DW_CFA_offset_extended 0x05 #define DW_CFA_restore_extended 0x06 #define DW_CFA_undefined 0x07 #define DW_CFA_same_value 0x08 #define DW_CFA_register 0x09 #define DW_CFA_remember_state 0x0a #define DW_CFA_restore_state 0x0b #define DW_CFA_def_cfa 0x0c #define DW_CFA_def_cfa_register 0x0d #define DW_CFA_def_cfa_offset 0x0e #define DW_CFA_def_cfa_expression 0x0f #define DW_CFA_expression 0x10 #define DW_CFA_offset_extended_sf 0x11 #define DW_CFA_def_cfa_sf 0x12 #define DW_CFA_def_cfa_offset_sf 0x13 #define DW_CFA_val_offset 0x14 #define DW_CFA_val_offset_sf 0x15 #define DW_CFA_val_expression 0x16 #define DW_CFA_lo_user 0x1c #define DW_CFA_GNU_window_save 0x2d #define DW_CFA_GNU_args_size 0x2e #define DW_CFA_GNU_negative_offset_extended 0x2f #define DW_CFA_hi_user 0x3f #define DW_EH_PE_FORM 0x07 #define DW_EH_PE_native 0x00 #define DW_EH_PE_leb128 0x01 #define DW_EH_PE_data2 0x02 #define DW_EH_PE_data4 0x03 #define DW_EH_PE_data8 0x04 #define DW_EH_PE_signed 0x08 #define DW_EH_PE_ADJUST 0x70 #define DW_EH_PE_abs 0x00 #define DW_EH_PE_pcrel 0x10 #define DW_EH_PE_textrel 0x20 #define DW_EH_PE_datarel 0x30 #define DW_EH_PE_funcrel 0x40 #define DW_EH_PE_aligned 0x50 #define DW_EH_PE_indirect 0x80 #define DW_EH_PE_omit 0xff typedef unsigned long uleb128_t; typedef signed long sleb128_t; static struct unwind_table { struct { unsigned long pc; unsigned long range; } core, init; const void *address; unsigned long size; const unsigned char *header; unsigned long hdrsz; struct unwind_table *link; const char *name; } root_table; struct unwind_item { enum item_location { Nowhere, Memory, Register, Value } where; uleb128_t value; }; struct unwind_state { uleb128_t loc, org; const u8 *cieStart, *cieEnd; uleb128_t codeAlign; sleb128_t dataAlign; struct cfa { uleb128_t reg, offs; } cfa; struct unwind_item regs[ARRAY_SIZE(reg_info)]; unsigned stackDepth:8; unsigned version:8; const u8 *label; const u8 *stack[MAX_STACK_DEPTH]; }; static const struct cfa badCFA = { ARRAY_SIZE(reg_info), 1 }; static struct unwind_table *find_table(unsigned long pc) { struct unwind_table *table; for (table = &root_table; table; table = table->link) if ((pc >= table->core.pc && pc < table->core.pc + table->core.range) || (pc >= table->init.pc && pc < table->init.pc + table->init.range)) break; return table; } static unsigned long read_pointer(const u8 **pLoc, const void *end, signed ptrType); static void init_unwind_table(struct unwind_table *table, const char *name, const void *core_start, unsigned long core_size, const void *init_start, unsigned long init_size, const void *table_start, unsigned long table_size, const u8 *header_start, unsigned long header_size) { const u8 *ptr = header_start + 4; const u8 *end = header_start + header_size; table->core.pc = (unsigned long)core_start; table->core.range = core_size; table->init.pc = (unsigned long)init_start; table->init.range = init_size; table->address = table_start; table->size = table_size; /* See if the linker provided table looks valid. */ if (header_size <= 4 || header_start[0] != 1 || (void *)read_pointer(&ptr, end, header_start[1]) != table_start || header_start[2] == DW_EH_PE_omit || read_pointer(&ptr, end, header_start[2]) <= 0 || header_start[3] == DW_EH_PE_omit) header_start = NULL; table->hdrsz = header_size; smp_wmb(); table->header = header_start; table->link = NULL; table->name = name; } void __init arc_unwind_init(void) { init_unwind_table(&root_table, "kernel", _text, _end - _text, NULL, 0, __start_unwind, __end_unwind - __start_unwind, NULL, 0); /*__start_unwind_hdr, __end_unwind_hdr - __start_unwind_hdr);*/ } static const u32 bad_cie, not_fde; static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *); static signed fde_pointer_type(const u32 *cie); struct eh_frame_hdr_table_entry { unsigned long start, fde; }; static int cmp_eh_frame_hdr_table_entries(const void *p1, const void *p2) { const struct eh_frame_hdr_table_entry *e1 = p1; const struct eh_frame_hdr_table_entry *e2 = p2; return (e1->start > e2->start) - (e1->start < e2->start); } static void swap_eh_frame_hdr_table_entries(void *p1, void *p2, int size) { struct eh_frame_hdr_table_entry *e1 = p1; struct eh_frame_hdr_table_entry *e2 = p2; unsigned long v; v = e1->start; e1->start = e2->start; e2->start = v; v = e1->fde; e1->fde = e2->fde; e2->fde = v; } static void __init setup_unwind_table(struct unwind_table *table, void *(*alloc) (unsigned long)) { const u8 *ptr; unsigned long tableSize = table->size, hdrSize; unsigned n; const u32 *fde; struct { u8 version; u8 eh_frame_ptr_enc; u8 fde_count_enc; u8 table_enc; unsigned long eh_frame_ptr; unsigned int fde_count; struct eh_frame_hdr_table_entry table[]; } __attribute__ ((__packed__)) *header; if (table->header) return; if (table->hdrsz) pr_warn(".eh_frame_hdr for '%s' present but unusable\n", table->name); if (tableSize & (sizeof(*fde) - 1)) return; for (fde = table->address, n = 0; tableSize > sizeof(*fde) && tableSize - sizeof(*fde) >= *fde; tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) { const u32 *cie = cie_for_fde(fde, table); signed ptrType; if (cie == ¬_fde) continue; if (cie == NULL || cie == &bad_cie) return; ptrType = fde_pointer_type(cie); if (ptrType < 0) return; ptr = (const u8 *)(fde + 2); if (!read_pointer(&ptr, (const u8 *)(fde + 1) + *fde, ptrType)) { /* FIXME_Rajesh We have 4 instances of null addresses * instead of the initial loc addr * return; */ WARN(1, "unwinder: FDE->initial_location NULL %p\n", (const u8 *)(fde + 1) + *fde); } ++n; } if (tableSize || !n) return; hdrSize = 4 + sizeof(unsigned long) + sizeof(unsigned int) + 2 * n * sizeof(unsigned long); header = alloc(hdrSize); if (!header) return; header->version = 1; header->eh_frame_ptr_enc = DW_EH_PE_abs | DW_EH_PE_native; header->fde_count_enc = DW_EH_PE_abs | DW_EH_PE_data4; header->table_enc = DW_EH_PE_abs | DW_EH_PE_native; put_unaligned((unsigned long)table->address, &header->eh_frame_ptr); BUILD_BUG_ON(offsetof(typeof(*header), fde_count) % __alignof(typeof(header->fde_count))); header->fde_count = n; BUILD_BUG_ON(offsetof(typeof(*header), table) % __alignof(typeof(*header->table))); for (fde = table->address, tableSize = table->size, n = 0; tableSize; tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) { /* const u32 *cie = fde + 1 - fde[1] / sizeof(*fde); */ const u32 *cie = (const u32 *)(fde[1]); if (fde[1] == 0xffffffff) continue; /* this is a CIE */ ptr = (const u8 *)(fde + 2); header->table[n].start = read_pointer(&ptr, (const u8 *)(fde + 1) + *fde, fde_pointer_type(cie)); header->table[n].fde = (unsigned long)fde; ++n; } WARN_ON(n != header->fde_count); sort(header->table, n, sizeof(*header->table), cmp_eh_frame_hdr_table_entries, swap_eh_frame_hdr_table_entries); table->hdrsz = hdrSize; smp_wmb(); table->header = (const void *)header; } static void *__init balloc(unsigned long sz) { return __alloc_bootmem_nopanic(sz, sizeof(unsigned int), __pa(MAX_DMA_ADDRESS)); } void __init arc_unwind_setup(void) { setup_unwind_table(&root_table, balloc); } #ifdef CONFIG_MODULES static struct unwind_table *last_table; /* Must be called with module_mutex held. */ void *unwind_add_table(struct module *module, const void *table_start, unsigned long table_size) { struct unwind_table *table; if (table_size <= 0) return NULL; table = kmalloc(sizeof(*table), GFP_KERNEL); if (!table) return NULL; init_unwind_table(table, module->name, module->module_core, module->core_size, module->module_init, module->init_size, table_start, table_size, NULL, 0); #ifdef UNWIND_DEBUG unw_debug("Table added for [%s] %lx %lx\n", module->name, table->core.pc, table->core.range); #endif if (last_table) last_table->link = table; else root_table.link = table; last_table = table; return table; } struct unlink_table_info { struct unwind_table *table; int init_only; }; static int unlink_table(void *arg) { struct unlink_table_info *info = arg; struct unwind_table *table = info->table, *prev; for (prev = &root_table; prev->link && prev->link != table; prev = prev->link) ; if (prev->link) { if (info->init_only) { table->init.pc = 0; table->init.range = 0; info->table = NULL; } else { prev->link = table->link; if (!prev->link) last_table = prev; } } else info->table = NULL; return 0; } /* Must be called with module_mutex held. */ void unwind_remove_table(void *handle, int init_only) { struct unwind_table *table = handle; struct unlink_table_info info; if (!table || table == &root_table) return; if (init_only && table == last_table) { table->init.pc = 0; table->init.range = 0; return; } info.table = table; info.init_only = init_only; unlink_table(&info); /* XXX: SMP */ kfree(table); } #endif /* CONFIG_MODULES */ static uleb128_t get_uleb128(const u8 **pcur, const u8 *end) { const u8 *cur = *pcur; uleb128_t value; unsigned shift; for (shift = 0, value = 0; cur < end; shift += 7) { if (shift + 7 > 8 * sizeof(value) && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) { cur = end + 1; break; } value |= (uleb128_t) (*cur & 0x7f) << shift; if (!(*cur++ & 0x80)) break; } *pcur = cur; return value; } static sleb128_t get_sleb128(const u8 **pcur, const u8 *end) { const u8 *cur = *pcur; sleb128_t value; unsigned shift; for (shift = 0, value = 0; cur < end; shift += 7) { if (shift + 7 > 8 * sizeof(value) && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) { cur = end + 1; break; } value |= (sleb128_t) (*cur & 0x7f) << shift; if (!(*cur & 0x80)) { value |= -(*cur++ & 0x40) << shift; break; } } *pcur = cur; return value; } static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *table) { const u32 *cie; if (!*fde || (*fde & (sizeof(*fde) - 1))) return &bad_cie; if (fde[1] == 0xffffffff) return ¬_fde; /* this is a CIE */ if ((fde[1] & (sizeof(*fde) - 1))) /* || fde[1] > (unsigned long)(fde + 1) - (unsigned long)table->address) */ return NULL; /* this is not a valid FDE */ /* cie = fde + 1 - fde[1] / sizeof(*fde); */ cie = (u32 *) fde[1]; if (*cie <= sizeof(*cie) + 4 || *cie >= fde[1] - sizeof(*fde) || (*cie & (sizeof(*cie) - 1)) || (cie[1] != 0xffffffff)) return NULL; /* this is not a (valid) CIE */ return cie; } static unsigned long read_pointer(const u8 **pLoc, const void *end, signed ptrType) { unsigned long value = 0; union { const u8 *p8; const u16 *p16u; const s16 *p16s; const u32 *p32u; const s32 *p32s; const unsigned long *pul; } ptr; if (ptrType < 0 || ptrType == DW_EH_PE_omit) return 0; ptr.p8 = *pLoc; switch (ptrType & DW_EH_PE_FORM) { case DW_EH_PE_data2: if (end < (const void *)(ptr.p16u + 1)) return 0; if (ptrType & DW_EH_PE_signed) value = get_unaligned((u16 *) ptr.p16s++); else value = get_unaligned((u16 *) ptr.p16u++); break; case DW_EH_PE_data4: #ifdef CONFIG_64BIT if (end < (const void *)(ptr.p32u + 1)) return 0; if (ptrType & DW_EH_PE_signed) value = get_unaligned(ptr.p32s++); else value = get_unaligned(ptr.p32u++); break; case DW_EH_PE_data8: BUILD_BUG_ON(sizeof(u64) != sizeof(value)); #else BUILD_BUG_ON(sizeof(u32) != sizeof(value)); #endif case DW_EH_PE_native: if (end < (const void *)(ptr.pul + 1)) return 0; value = get_unaligned((unsigned long *)ptr.pul++); break; case DW_EH_PE_leb128: BUILD_BUG_ON(sizeof(uleb128_t) > sizeof(value)); value = ptrType & DW_EH_PE_signed ? get_sleb128(&ptr.p8, end) : get_uleb128(&ptr.p8, end); if ((const void *)ptr.p8 > end) return 0; break; default: return 0; } switch (ptrType & DW_EH_PE_ADJUST) { case DW_EH_PE_abs: break; case DW_EH_PE_pcrel: value += (unsigned long)*pLoc; break; default: return 0; } if ((ptrType & DW_EH_PE_indirect) && __get_user(value, (unsigned long __user *)value)) return 0; *pLoc = ptr.p8; return value; } static signed fde_pointer_type(const u32 *cie) { const u8 *ptr = (const u8 *)(cie + 2); unsigned version = *ptr; if (version != 1) return -1; /* unsupported */ if (*++ptr) { const char *aug; const u8 *end = (const u8 *)(cie + 1) + *cie; uleb128_t len; /* check if augmentation size is first (and thus present) */ if (*ptr != 'z') return -1; /* check if augmentation string is nul-terminated */ aug = (const void *)ptr; ptr = memchr(aug, 0, end - ptr); if (ptr == NULL) return -1; ++ptr; /* skip terminator */ get_uleb128(&ptr, end); /* skip code alignment */ get_sleb128(&ptr, end); /* skip data alignment */ /* skip return address column */ version <= 1 ? (void) ++ptr : (void)get_uleb128(&ptr, end); len = get_uleb128(&ptr, end); /* augmentation length */ if (ptr + len < ptr || ptr + len > end) return -1; end = ptr + len; while (*++aug) { if (ptr >= end) return -1; switch (*aug) { case 'L': ++ptr; break; case 'P':{ signed ptrType = *ptr++; if (!read_pointer(&ptr, end, ptrType) || ptr > end) return -1; } break; case 'R': return *ptr; default: return -1; } } } return DW_EH_PE_native | DW_EH_PE_abs; } static int advance_loc(unsigned long delta, struct unwind_state *state) { state->loc += delta * state->codeAlign; /* FIXME_Rajesh: Probably we are defining for the initial range as well; return delta > 0; */ unw_debug("delta %3lu => loc 0x%lx: ", delta, state->loc); return 1; } static void set_rule(uleb128_t reg, enum item_location where, uleb128_t value, struct unwind_state *state) { if (reg < ARRAY_SIZE(state->regs)) { state->regs[reg].where = where; state->regs[reg].value = value; #ifdef UNWIND_DEBUG unw_debug("r%lu: ", reg); switch (where) { case Nowhere: unw_debug("s "); break; case Memory: unw_debug("c(%lu) ", value); break; case Register: unw_debug("r(%lu) ", value); break; case Value: unw_debug("v(%lu) ", value); break; default: break; } #endif } } static int processCFI(const u8 *start, const u8 *end, unsigned long targetLoc, signed ptrType, struct unwind_state *state) { union { const u8 *p8; const u16 *p16; const u32 *p32; } ptr; int result = 1; u8 opcode; if (start != state->cieStart) { state->loc = state->org; result = processCFI(state->cieStart, state->cieEnd, 0, ptrType, state); if (targetLoc == 0 && state->label == NULL) return result; } for (ptr.p8 = start; result && ptr.p8 < end;) { switch (*ptr.p8 >> 6) { uleb128_t value; case 0: opcode = *ptr.p8++; switch (opcode) { case DW_CFA_nop: unw_debug("cfa nop "); break; case DW_CFA_set_loc: state->loc = read_pointer(&ptr.p8, end, ptrType); if (state->loc == 0) result = 0; unw_debug("cfa_set_loc: 0x%lx ", state->loc); break; case DW_CFA_advance_loc1: unw_debug("\ncfa advance loc1:"); result = ptr.p8 < end && advance_loc(*ptr.p8++, state); break; case DW_CFA_advance_loc2: value = *ptr.p8++; value += *ptr.p8++ << 8; unw_debug("\ncfa advance loc2:"); result = ptr.p8 <= end + 2 /* && advance_loc(*ptr.p16++, state); */ && advance_loc(value, state); break; case DW_CFA_advance_loc4: unw_debug("\ncfa advance loc4:"); result = ptr.p8 <= end + 4 && advance_loc(*ptr.p32++, state); break; case DW_CFA_offset_extended: value = get_uleb128(&ptr.p8, end); unw_debug("cfa_offset_extended: "); set_rule(value, Memory, get_uleb128(&ptr.p8, end), state); break; case DW_CFA_val_offset: value = get_uleb128(&ptr.p8, end); set_rule(value, Value, get_uleb128(&ptr.p8, end), state); break; case DW_CFA_offset_extended_sf: value = get_uleb128(&ptr.p8, end); set_rule(value, Memory, get_sleb128(&ptr.p8, end), state); break; case DW_CFA_val_offset_sf: value = get_uleb128(&ptr.p8, end); set_rule(value, Value, get_sleb128(&ptr.p8, end), state); break; case DW_CFA_restore_extended: unw_debug("cfa_restore_extended: "); case DW_CFA_undefined: unw_debug("cfa_undefined: "); case DW_CFA_same_value: unw_debug("cfa_same_value: "); set_rule(get_uleb128(&ptr.p8, end), Nowhere, 0, state); break; case DW_CFA_register: unw_debug("cfa_register: "); value = get_uleb128(&ptr.p8, end); set_rule(value, Register, get_uleb128(&ptr.p8, end), state); break; case DW_CFA_remember_state: unw_debug("cfa_remember_state: "); if (ptr.p8 == state->label) { state->label = NULL; return 1; } if (state->stackDepth >= MAX_STACK_DEPTH) return 0; state->stack[state->stackDepth++] = ptr.p8; break; case DW_CFA_restore_state: unw_debug("cfa_restore_state: "); if (state->stackDepth) { const uleb128_t loc = state->loc; const u8 *label = state->label; state->label = state->stack[state->stackDepth - 1]; memcpy(&state->cfa, &badCFA, sizeof(state->cfa)); memset(state->regs, 0, sizeof(state->regs)); state->stackDepth = 0; result = processCFI(start, end, 0, ptrType, state); state->loc = loc; state->label = label; } else return 0; break; case DW_CFA_def_cfa: state->cfa.reg = get_uleb128(&ptr.p8, end); unw_debug("cfa_def_cfa: r%lu ", state->cfa.reg); /*nobreak*/ case DW_CFA_def_cfa_offset: state->cfa.offs = get_uleb128(&ptr.p8, end); unw_debug("cfa_def_cfa_offset: 0x%lx ", state->cfa.offs); break; case DW_CFA_def_cfa_sf: state->cfa.reg = get_uleb128(&ptr.p8, end); /*nobreak */ case DW_CFA_def_cfa_offset_sf: state->cfa.offs = get_sleb128(&ptr.p8, end) * state->dataAlign; break; case DW_CFA_def_cfa_register: unw_debug("cfa_def_cfa_regsiter: "); state->cfa.reg = get_uleb128(&ptr.p8, end); break; /*todo case DW_CFA_def_cfa_expression: */ /*todo case DW_CFA_expression: */ /*todo case DW_CFA_val_expression: */ case DW_CFA_GNU_args_size: get_uleb128(&ptr.p8, end); break; case DW_CFA_GNU_negative_offset_extended: value = get_uleb128(&ptr.p8, end); set_rule(value, Memory, (uleb128_t) 0 - get_uleb128(&ptr.p8, end), state); break; case DW_CFA_GNU_window_save: default: unw_debug("UNKNOW OPCODE 0x%x\n", opcode); result = 0; break; } break; case 1: unw_debug("\ncfa_adv_loc: "); result = advance_loc(*ptr.p8++ & 0x3f, state); break; case 2: unw_debug("cfa_offset: "); value = *ptr.p8++ & 0x3f; set_rule(value, Memory, get_uleb128(&ptr.p8, end), state); break; case 3: unw_debug("cfa_restore: "); set_rule(*ptr.p8++ & 0x3f, Nowhere, 0, state); break; } if (ptr.p8 > end) result = 0; if (result && targetLoc != 0 && targetLoc < state->loc) return 1; } return result && ptr.p8 == end && (targetLoc == 0 || ( /*todo While in theory this should apply, gcc in practice omits everything past the function prolog, and hence the location never reaches the end of the function. targetLoc < state->loc && */ state->label == NULL)); } /* Unwind to previous to frame. Returns 0 if successful, negative * number in case of an error. */ int arc_unwind(struct unwind_frame_info *frame) { #define FRAME_REG(r, t) (((t *)frame)[reg_info[r].offs]) const u32 *fde = NULL, *cie = NULL; const u8 *ptr = NULL, *end = NULL; unsigned long pc = UNW_PC(frame) - frame->call_frame; unsigned long startLoc = 0, endLoc = 0, cfa; unsigned i; signed ptrType = -1; uleb128_t retAddrReg = 0; const struct unwind_table *table; struct unwind_state state; unsigned long *fptr; unsigned long addr; unw_debug("\n\nUNWIND FRAME:\n"); unw_debug("PC: 0x%lx BLINK: 0x%lx, SP: 0x%lx, FP: 0x%x\n", UNW_PC(frame), UNW_BLINK(frame), UNW_SP(frame), UNW_FP(frame)); if (UNW_PC(frame) == 0) return -EINVAL; #ifdef UNWIND_DEBUG { unsigned long *sptr = (unsigned long *)UNW_SP(frame); unw_debug("\nStack Dump:\n"); for (i = 0; i < 20; i++, sptr++) unw_debug("0x%p: 0x%lx\n", sptr, *sptr); unw_debug("\n"); } #endif table = find_table(pc); if (table != NULL && !(table->size & (sizeof(*fde) - 1))) { const u8 *hdr = table->header; unsigned long tableSize; smp_rmb(); if (hdr && hdr[0] == 1) { switch (hdr[3] & DW_EH_PE_FORM) { case DW_EH_PE_native: tableSize = sizeof(unsigned long); break; case DW_EH_PE_data2: tableSize = 2; break; case DW_EH_PE_data4: tableSize = 4; break; case DW_EH_PE_data8: tableSize = 8; break; default: tableSize = 0; break; } ptr = hdr + 4; end = hdr + table->hdrsz; if (tableSize && read_pointer(&ptr, end, hdr[1]) == (unsigned long)table->address && (i = read_pointer(&ptr, end, hdr[2])) > 0 && i == (end - ptr) / (2 * tableSize) && !((end - ptr) % (2 * tableSize))) { do { const u8 *cur = ptr + (i / 2) * (2 * tableSize); startLoc = read_pointer(&cur, cur + tableSize, hdr[3]); if (pc < startLoc) i /= 2; else { ptr = cur - tableSize; i = (i + 1) / 2; } } while (startLoc && i > 1); if (i == 1 && (startLoc = read_pointer(&ptr, ptr + tableSize, hdr[3])) != 0 && pc >= startLoc) fde = (void *)read_pointer(&ptr, ptr + tableSize, hdr[3]); } } if (fde != NULL) { cie = cie_for_fde(fde, table); ptr = (const u8 *)(fde + 2); if (cie != NULL && cie != &bad_cie && cie != ¬_fde && (ptrType = fde_pointer_type(cie)) >= 0 && read_pointer(&ptr, (const u8 *)(fde + 1) + *fde, ptrType) == startLoc) { if (!(ptrType & DW_EH_PE_indirect)) ptrType &= DW_EH_PE_FORM | DW_EH_PE_signed; endLoc = startLoc + read_pointer(&ptr, (const u8 *)(fde + 1) + *fde, ptrType); if (pc >= endLoc) fde = NULL; } else fde = NULL; } if (fde == NULL) { for (fde = table->address, tableSize = table->size; cie = NULL, tableSize > sizeof(*fde) && tableSize - sizeof(*fde) >= *fde; tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) { cie = cie_for_fde(fde, table); if (cie == &bad_cie) { cie = NULL; break; } if (cie == NULL || cie == ¬_fde || (ptrType = fde_pointer_type(cie)) < 0) continue; ptr = (const u8 *)(fde + 2); startLoc = read_pointer(&ptr, (const u8 *)(fde + 1) + *fde, ptrType); if (!startLoc) continue; if (!(ptrType & DW_EH_PE_indirect)) ptrType &= DW_EH_PE_FORM | DW_EH_PE_signed; endLoc = startLoc + read_pointer(&ptr, (const u8 *)(fde + 1) + *fde, ptrType); if (pc >= startLoc && pc < endLoc) break; } } } if (cie != NULL) { memset(&state, 0, sizeof(state)); state.cieEnd = ptr; /* keep here temporarily */ ptr = (const u8 *)(cie + 2); end = (const u8 *)(cie + 1) + *cie; frame->call_frame = 1; if ((state.version = *ptr) != 1) cie = NULL; /* unsupported version */ else if (*++ptr) { /* check if augmentation size is first (thus present) */ if (*ptr == 'z') { while (++ptr < end && *ptr) { switch (*ptr) { /* chk for ignorable or already handled * nul-terminated augmentation string */ case 'L': case 'P': case 'R': continue; case 'S': frame->call_frame = 0; continue; default: break; } break; } } if (ptr >= end || *ptr) cie = NULL; } ++ptr; } if (cie != NULL) { /* get code aligment factor */ state.codeAlign = get_uleb128(&ptr, end); /* get data aligment factor */ state.dataAlign = get_sleb128(&ptr, end); if (state.codeAlign == 0 || state.dataAlign == 0 || ptr >= end) cie = NULL; else { retAddrReg = state.version <= 1 ? *ptr++ : get_uleb128(&ptr, end); unw_debug("CIE Frame Info:\n"); unw_debug("return Address register 0x%lx\n", retAddrReg); unw_debug("data Align: %ld\n", state.dataAlign); unw_debug("code Align: %lu\n", state.codeAlign); /* skip augmentation */ if (((const char *)(cie + 2))[1] == 'z') { uleb128_t augSize = get_uleb128(&ptr, end); ptr += augSize; } if (ptr > end || retAddrReg >= ARRAY_SIZE(reg_info) || REG_INVALID(retAddrReg) || reg_info[retAddrReg].width != sizeof(unsigned long)) cie = NULL; } } if (cie != NULL) { state.cieStart = ptr; ptr = state.cieEnd; state.cieEnd = end; end = (const u8 *)(fde + 1) + *fde; /* skip augmentation */ if (((const char *)(cie + 2))[1] == 'z') { uleb128_t augSize = get_uleb128(&ptr, end); if ((ptr += augSize) > end) fde = NULL; } } if (cie == NULL || fde == NULL) { #ifdef CONFIG_FRAME_POINTER unsigned long top, bottom; top = STACK_TOP_UNW(frame->task); bottom = STACK_BOTTOM_UNW(frame->task); #if FRAME_RETADDR_OFFSET < 0 if (UNW_SP(frame) < top && UNW_FP(frame) <= UNW_SP(frame) && bottom < UNW_FP(frame) #else if (UNW_SP(frame) > top && UNW_FP(frame) >= UNW_SP(frame) && bottom > UNW_FP(frame) #endif && !((UNW_SP(frame) | UNW_FP(frame)) & (sizeof(unsigned long) - 1))) { unsigned long link; if (!__get_user(link, (unsigned long *) (UNW_FP(frame) + FRAME_LINK_OFFSET)) #if FRAME_RETADDR_OFFSET < 0 && link > bottom && link < UNW_FP(frame) #else && link > UNW_FP(frame) && link < bottom #endif && !(link & (sizeof(link) - 1)) && !__get_user(UNW_PC(frame), (unsigned long *)(UNW_FP(frame) + FRAME_RETADDR_OFFSET))) { UNW_SP(frame) = UNW_FP(frame) + FRAME_RETADDR_OFFSET #if FRAME_RETADDR_OFFSET < 0 - #else + #endif sizeof(UNW_PC(frame)); UNW_FP(frame) = link; return 0; } } #endif return -ENXIO; } state.org = startLoc; memcpy(&state.cfa, &badCFA, sizeof(state.cfa)); unw_debug("\nProcess instructions\n"); /* process instructions * For ARC, we optimize by having blink(retAddrReg) with * the sameValue in the leaf function, so we should not check * state.regs[retAddrReg].where == Nowhere */ if (!processCFI(ptr, end, pc, ptrType, &state) || state.loc > endLoc /* || state.regs[retAddrReg].where == Nowhere */ || state.cfa.reg >= ARRAY_SIZE(reg_info) || reg_info[state.cfa.reg].width != sizeof(unsigned long) || state.cfa.offs % sizeof(unsigned long)) return -EIO; #ifdef UNWIND_DEBUG unw_debug("\n"); unw_debug("\nRegister State Based on the rules parsed from FDE:\n"); for (i = 0; i < ARRAY_SIZE(state.regs); ++i) { if (REG_INVALID(i)) continue; switch (state.regs[i].where) { case Nowhere: break; case Memory: unw_debug(" r%d: c(%lu),", i, state.regs[i].value); break; case Register: unw_debug(" r%d: r(%lu),", i, state.regs[i].value); break; case Value: unw_debug(" r%d: v(%lu),", i, state.regs[i].value); break; } } unw_debug("\n"); #endif /* update frame */ #ifndef CONFIG_AS_CFI_SIGNAL_FRAME if (frame->call_frame && !UNW_DEFAULT_RA(state.regs[retAddrReg], state.dataAlign)) frame->call_frame = 0; #endif cfa = FRAME_REG(state.cfa.reg, unsigned long) + state.cfa.offs; startLoc = min_t(unsigned long, UNW_SP(frame), cfa); endLoc = max_t(unsigned long, UNW_SP(frame), cfa); if (STACK_LIMIT(startLoc) != STACK_LIMIT(endLoc)) { startLoc = min(STACK_LIMIT(cfa), cfa); endLoc = max(STACK_LIMIT(cfa), cfa); } unw_debug("\nCFA reg: 0x%lx, offset: 0x%lx => 0x%lx\n", state.cfa.reg, state.cfa.offs, cfa); for (i = 0; i < ARRAY_SIZE(state.regs); ++i) { if (REG_INVALID(i)) { if (state.regs[i].where == Nowhere) continue; return -EIO; } switch (state.regs[i].where) { default: break; case Register: if (state.regs[i].value >= ARRAY_SIZE(reg_info) || REG_INVALID(state.regs[i].value) || reg_info[i].width > reg_info[state.regs[i].value].width) return -EIO; switch (reg_info[state.regs[i].value].width) { case sizeof(u8): state.regs[i].value = FRAME_REG(state.regs[i].value, const u8); break; case sizeof(u16): state.regs[i].value = FRAME_REG(state.regs[i].value, const u16); break; case sizeof(u32): state.regs[i].value = FRAME_REG(state.regs[i].value, const u32); break; #ifdef CONFIG_64BIT case sizeof(u64): state.regs[i].value = FRAME_REG(state.regs[i].value, const u64); break; #endif default: return -EIO; } break; } } unw_debug("\nRegister state after evaluation with realtime Stack:\n"); fptr = (unsigned long *)(&frame->regs); for (i = 0; i < ARRAY_SIZE(state.regs); ++i, fptr++) { if (REG_INVALID(i)) continue; switch (state.regs[i].where) { case Nowhere: if (reg_info[i].width != sizeof(UNW_SP(frame)) || &FRAME_REG(i, __typeof__(UNW_SP(frame))) != &UNW_SP(frame)) continue; UNW_SP(frame) = cfa; break; case Register: switch (reg_info[i].width) { case sizeof(u8): FRAME_REG(i, u8) = state.regs[i].value; break; case sizeof(u16): FRAME_REG(i, u16) = state.regs[i].value; break; case sizeof(u32): FRAME_REG(i, u32) = state.regs[i].value; break; #ifdef CONFIG_64BIT case sizeof(u64): FRAME_REG(i, u64) = state.regs[i].value; break; #endif default: return -EIO; } break; case Value: if (reg_info[i].width != sizeof(unsigned long)) return -EIO; FRAME_REG(i, unsigned long) = cfa + state.regs[i].value * state.dataAlign; break; case Memory: addr = cfa + state.regs[i].value * state.dataAlign; if ((state.regs[i].value * state.dataAlign) % sizeof(unsigned long) || addr < startLoc || addr + sizeof(unsigned long) < addr || addr + sizeof(unsigned long) > endLoc) return -EIO; switch (reg_info[i].width) { case sizeof(u8): __get_user(FRAME_REG(i, u8), (u8 __user *)addr); break; case sizeof(u16): __get_user(FRAME_REG(i, u16), (u16 __user *)addr); break; case sizeof(u32): __get_user(FRAME_REG(i, u32), (u32 __user *)addr); break; #ifdef CONFIG_64BIT case sizeof(u64): __get_user(FRAME_REG(i, u64), (u64 __user *)addr); break; #endif default: return -EIO; } break; } unw_debug("r%d: 0x%lx ", i, *fptr); } return 0; #undef FRAME_REG } EXPORT_SYMBOL(arc_unwind);