| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) |
| * Copyright (C) 2002-2006 Novell, Inc. |
| * Jan Beulich <jbeulich@novell.com> |
| * |
| * A simple API for unwinding kernel stacks. This is used for |
| * debugging and error reporting purposes. The kernel doesn't need |
| * full-blown stack unwinding with all the bells and whistles, so there |
| * is not much point in implementing the full Dwarf2 unwind API. |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/module.h> |
| #include <linux/memblock.h> |
| #include <linux/sort.h> |
| #include <linux/slab.h> |
| #include <linux/stop_machine.h> |
| #include <linux/uaccess.h> |
| #include <linux/ptrace.h> |
| #include <asm/sections.h> |
| #include <asm/unaligned.h> |
| #include <asm/unwind.h> |
| |
| extern char __start_unwind[], __end_unwind[]; |
| /* extern const u8 __start_unwind_hdr[], __end_unwind_hdr[];*/ |
| |
| /* #define UNWIND_DEBUG */ |
| |
| #ifdef UNWIND_DEBUG |
| int dbg_unw; |
| #define unw_debug(fmt, ...) \ |
| do { \ |
| if (dbg_unw) \ |
| pr_info(fmt, ##__VA_ARGS__); \ |
| } while (0); |
| #else |
| #define unw_debug(fmt, ...) |
| #endif |
| |
| #define MAX_STACK_DEPTH 8 |
| |
| #define EXTRA_INFO(f) { \ |
| BUILD_BUG_ON_ZERO(offsetof(struct unwind_frame_info, f) \ |
| % sizeof_field(struct unwind_frame_info, f)) \ |
| + offsetof(struct unwind_frame_info, f) \ |
| / sizeof_field(struct unwind_frame_info, f), \ |
| sizeof_field(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 |
| |
| #define CIE_ID 0 |
| |
| 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_hdr(struct unwind_table *table, |
| void *(*alloc) (unsigned long)); |
| |
| /* |
| * wrappers for header alloc (vs. calling one vs. other at call site) |
| * to elide section mismatches warnings |
| */ |
| static void *__init unw_hdr_alloc_early(unsigned long sz) |
| { |
| return memblock_alloc_from(sz, sizeof(unsigned int), MAX_DMA_ADDRESS); |
| } |
| |
| 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) |
| { |
| 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; |
| /* To avoid the pointer addition with NULL pointer.*/ |
| if (header_start != NULL) { |
| const u8 *ptr = header_start + 4; |
| const u8 *end = header_start + header_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);*/ |
| |
| init_unwind_hdr(&root_table, unw_hdr_alloc_early); |
| } |
| |
| static const u32 bad_cie, not_fde; |
| static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *); |
| static const u32 *__cie_for_fde(const u32 *fde); |
| 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_unwind_hdr(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) |
| goto ret_err; |
| ptrType = fde_pointer_type(cie); |
| if (ptrType < 0) |
| goto ret_err; |
| |
| 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) |
| goto ret_err; |
| |
| hdrSize = 4 + sizeof(unsigned long) + sizeof(unsigned int) |
| + 2 * n * sizeof(unsigned long); |
| |
| header = alloc(hdrSize); |
| if (!header) |
| goto ret_err; |
| |
| 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 = __cie_for_fde(fde); |
| |
| if (fde[1] == CIE_ID) |
| 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; |
| return; |
| |
| ret_err: |
| panic("Attention !!! Dwarf FDE parsing errors\n"); |
| } |
| |
| #ifdef CONFIG_MODULES |
| static void *unw_hdr_alloc(unsigned long sz) |
| { |
| return kmalloc(sz, GFP_KERNEL); |
| } |
| |
| 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->core_layout.base, module->core_layout.size, |
| module->init_layout.base, module->init_layout.size, |
| table_start, table_size, |
| NULL, 0); |
| |
| init_unwind_hdr(table, unw_hdr_alloc); |
| |
| #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->header); |
| kfree(table); |
| } |
| |
| #endif /* CONFIG_MODULES */ |
| |
| static uleb128_t get_uleb128(const u8 **pcur, const u8 *end) |
| { |
| const u8 *cur = *pcur; |
| uleb128_t value; |
| unsigned shift; |
| |
| for (shift = 0, value = 0; cur < end; shift += 7) { |
| if (shift + 7 > 8 * sizeof(value) |
| && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) { |
| cur = end + 1; |
| break; |
| } |
| value |= (uleb128_t) (*cur & 0x7f) << shift; |
| if (!(*cur++ & 0x80)) |
| break; |
| } |
| *pcur = cur; |
| |
| return value; |
| } |
| |
| static sleb128_t get_sleb128(const u8 **pcur, const u8 *end) |
| { |
| const u8 *cur = *pcur; |
| sleb128_t value; |
| unsigned shift; |
| |
| for (shift = 0, value = 0; cur < end; shift += 7) { |
| if (shift + 7 > 8 * sizeof(value) |
| && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) { |
| cur = end + 1; |
| break; |
| } |
| value |= (sleb128_t) (*cur & 0x7f) << shift; |
| if (!(*cur & 0x80)) { |
| value |= -(*cur++ & 0x40) << shift; |
| break; |
| } |
| } |
| *pcur = cur; |
| |
| return value; |
| } |
| |
| static const u32 *__cie_for_fde(const u32 *fde) |
| { |
| const u32 *cie; |
| |
| cie = fde + 1 - fde[1] / sizeof(*fde); |
| |
| return cie; |
| } |
| |
| static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *table) |
| { |
| const u32 *cie; |
| |
| if (!*fde || (*fde & (sizeof(*fde) - 1))) |
| return &bad_cie; |
| |
| if (fde[1] == CIE_ID) |
| return ¬_fde; /* this is a CIE */ |
| |
| if ((fde[1] & (sizeof(*fde) - 1))) |
| /* || fde[1] > (unsigned long)(fde + 1) - (unsigned long)table->address) */ |
| return NULL; /* this is not a valid FDE */ |
| |
| cie = __cie_for_fde(fde); |
| |
| if (*cie <= sizeof(*cie) + 4 || *cie >= fde[1] - sizeof(*fde) |
| || (*cie & (sizeof(*cie) - 1)) |
| || (cie[1] != CIE_ID)) |
| return NULL; /* this is not a (valid) CIE */ |
| return cie; |
| } |
| |
| static unsigned long read_pointer(const u8 **pLoc, const void *end, |
| signed ptrType) |
| { |
| unsigned long value = 0; |
| union { |
| const u8 *p8; |
| const u16 *p16u; |
| const s16 *p16s; |
| const u32 *p32u; |
| const s32 *p32s; |
| const unsigned long *pul; |
| } ptr; |
| |
| if (ptrType < 0 || ptrType == DW_EH_PE_omit) |
| return 0; |
| ptr.p8 = *pLoc; |
| switch (ptrType & DW_EH_PE_FORM) { |
| case DW_EH_PE_data2: |
| if (end < (const void *)(ptr.p16u + 1)) |
| return 0; |
| if (ptrType & DW_EH_PE_signed) |
| value = get_unaligned((u16 *) ptr.p16s++); |
| else |
| value = get_unaligned((u16 *) ptr.p16u++); |
| break; |
| case DW_EH_PE_data4: |
| #ifdef CONFIG_64BIT |
| if (end < (const void *)(ptr.p32u + 1)) |
| return 0; |
| if (ptrType & DW_EH_PE_signed) |
| value = get_unaligned(ptr.p32s++); |
| else |
| value = get_unaligned(ptr.p32u++); |
| break; |
| case DW_EH_PE_data8: |
| BUILD_BUG_ON(sizeof(u64) != sizeof(value)); |
| #else |
| BUILD_BUG_ON(sizeof(u32) != sizeof(value)); |
| #endif |
| fallthrough; |
| case DW_EH_PE_native: |
| if (end < (const void *)(ptr.pul + 1)) |
| return 0; |
| value = get_unaligned((unsigned long *)ptr.pul++); |
| break; |
| case DW_EH_PE_leb128: |
| BUILD_BUG_ON(sizeof(uleb128_t) > sizeof(value)); |
| value = ptrType & DW_EH_PE_signed ? get_sleb128(&ptr.p8, end) |
| : get_uleb128(&ptr.p8, end); |
| if ((const void *)ptr.p8 > end) |
| return 0; |
| break; |
| default: |
| return 0; |
| } |
| switch (ptrType & DW_EH_PE_ADJUST) { |
| case DW_EH_PE_abs: |
| break; |
| case DW_EH_PE_pcrel: |
| value += (unsigned long)*pLoc; |
| break; |
| default: |
| return 0; |
| } |
| if ((ptrType & DW_EH_PE_indirect) |
| && __get_user(value, (unsigned long __user *)value)) |
| return 0; |
| *pLoc = ptr.p8; |
| |
| return value; |
| } |
| |
| static signed fde_pointer_type(const u32 *cie) |
| { |
| const u8 *ptr = (const u8 *)(cie + 2); |
| unsigned version = *ptr; |
| |
| if (*++ptr) { |
| const char *aug; |
| const u8 *end = (const u8 *)(cie + 1) + *cie; |
| uleb128_t len; |
| |
| /* check if augmentation size is first (and thus present) */ |
| if (*ptr != 'z') |
| return -1; |
| |
| /* check if augmentation string is nul-terminated */ |
| aug = (const void *)ptr; |
| ptr = memchr(aug, 0, end - ptr); |
| if (ptr == NULL) |
| return -1; |
| |
| ++ptr; /* skip terminator */ |
| get_uleb128(&ptr, end); /* skip code alignment */ |
| get_sleb128(&ptr, end); /* skip data alignment */ |
| /* skip return address column */ |
| version <= 1 ? (void) ++ptr : (void)get_uleb128(&ptr, end); |
| len = get_uleb128(&ptr, end); /* augmentation length */ |
| |
| if (ptr + len < ptr || ptr + len > end) |
| return -1; |
| |
| end = ptr + len; |
| while (*++aug) { |
| if (ptr >= end) |
| return -1; |
| switch (*aug) { |
| case 'L': |
| ++ptr; |
| break; |
| case 'P':{ |
| signed ptrType = *ptr++; |
| |
| if (!read_pointer(&ptr, end, ptrType) |
| || ptr > end) |
| return -1; |
| } |
| break; |
| case 'R': |
| return *ptr; |
| default: |
| return -1; |
| } |
| } |
| } |
| return DW_EH_PE_native | DW_EH_PE_abs; |
| } |
| |
| static int advance_loc(unsigned long delta, struct unwind_state *state) |
| { |
| state->loc += delta * state->codeAlign; |
| |
| /* FIXME_Rajesh: Probably we are defining for the initial range as well; |
| return delta > 0; |
| */ |
| unw_debug("delta %3lu => loc 0x%lx: ", delta, state->loc); |
| return 1; |
| } |
| |
| static void set_rule(uleb128_t reg, enum item_location where, uleb128_t value, |
| struct unwind_state *state) |
| { |
| if (reg < ARRAY_SIZE(state->regs)) { |
| state->regs[reg].where = where; |
| state->regs[reg].value = value; |
| |
| #ifdef UNWIND_DEBUG |
| unw_debug("r%lu: ", reg); |
| switch (where) { |
| case Nowhere: |
| unw_debug("s "); |
| break; |
| case Memory: |
| unw_debug("c(%lu) ", value); |
| break; |
| case Register: |
| unw_debug("r(%lu) ", value); |
| break; |
| case Value: |
| unw_debug("v(%lu) ", value); |
| break; |
| default: |
| break; |
| } |
| #endif |
| } |
| } |
| |
| static int processCFI(const u8 *start, const u8 *end, unsigned long targetLoc, |
| signed ptrType, struct unwind_state *state) |
| { |
| union { |
| const u8 *p8; |
| const u16 *p16; |
| const u32 *p32; |
| } ptr; |
| int result = 1; |
| u8 opcode; |
| |
| if (start != state->cieStart) { |
| state->loc = state->org; |
| result = |
| processCFI(state->cieStart, state->cieEnd, 0, ptrType, |
| state); |
| if (targetLoc == 0 && state->label == NULL) |
| return result; |
| } |
| for (ptr.p8 = start; result && ptr.p8 < end;) { |
| switch (*ptr.p8 >> 6) { |
| uleb128_t value; |
| |
| case 0: |
| opcode = *ptr.p8++; |
| |
| switch (opcode) { |
| case DW_CFA_nop: |
| unw_debug("cfa nop "); |
| break; |
| case DW_CFA_set_loc: |
| state->loc = read_pointer(&ptr.p8, end, |
| ptrType); |
| if (state->loc == 0) |
| result = 0; |
| unw_debug("cfa_set_loc: 0x%lx ", state->loc); |
| break; |
| case DW_CFA_advance_loc1: |
| unw_debug("\ncfa advance loc1:"); |
| result = ptr.p8 < end |
| && advance_loc(*ptr.p8++, state); |
| break; |
| case DW_CFA_advance_loc2: |
| value = *ptr.p8++; |
| value += *ptr.p8++ << 8; |
| unw_debug("\ncfa advance loc2:"); |
| result = ptr.p8 <= end + 2 |
| /* && advance_loc(*ptr.p16++, state); */ |
| && advance_loc(value, state); |
| break; |
| case DW_CFA_advance_loc4: |
| unw_debug("\ncfa advance loc4:"); |
| result = ptr.p8 <= end + 4 |
| && advance_loc(*ptr.p32++, state); |
| break; |
| case DW_CFA_offset_extended: |
| value = get_uleb128(&ptr.p8, end); |
| unw_debug("cfa_offset_extended: "); |
| set_rule(value, Memory, |
| get_uleb128(&ptr.p8, end), state); |
| break; |
| case DW_CFA_val_offset: |
| value = get_uleb128(&ptr.p8, end); |
| set_rule(value, Value, |
| get_uleb128(&ptr.p8, end), state); |
| break; |
| case DW_CFA_offset_extended_sf: |
| value = get_uleb128(&ptr.p8, end); |
| set_rule(value, Memory, |
| get_sleb128(&ptr.p8, end), state); |
| break; |
| case DW_CFA_val_offset_sf: |
| value = get_uleb128(&ptr.p8, end); |
| set_rule(value, Value, |
| get_sleb128(&ptr.p8, end), state); |
| break; |
| case DW_CFA_restore_extended: |
| unw_debug("cfa_restore_extended: "); |
| case DW_CFA_undefined: |
| unw_debug("cfa_undefined: "); |
| case DW_CFA_same_value: |
| unw_debug("cfa_same_value: "); |
| set_rule(get_uleb128(&ptr.p8, end), Nowhere, 0, |
| state); |
| break; |
| case DW_CFA_register: |
| unw_debug("cfa_register: "); |
| value = get_uleb128(&ptr.p8, end); |
| set_rule(value, |
| Register, |
| get_uleb128(&ptr.p8, end), state); |
| break; |
| case DW_CFA_remember_state: |
| unw_debug("cfa_remember_state: "); |
| if (ptr.p8 == state->label) { |
| state->label = NULL; |
| return 1; |
| } |
| if (state->stackDepth >= MAX_STACK_DEPTH) |
| return 0; |
| state->stack[state->stackDepth++] = ptr.p8; |
| break; |
| case DW_CFA_restore_state: |
| unw_debug("cfa_restore_state: "); |
| if (state->stackDepth) { |
| const uleb128_t loc = state->loc; |
| const u8 *label = state->label; |
| |
| state->label = |
| state->stack[state->stackDepth - 1]; |
| memcpy(&state->cfa, &badCFA, |
| sizeof(state->cfa)); |
| memset(state->regs, 0, |
| sizeof(state->regs)); |
| state->stackDepth = 0; |
| result = |
| processCFI(start, end, 0, ptrType, |
| state); |
| state->loc = loc; |
| state->label = label; |
| } else |
| return 0; |
| break; |
| case DW_CFA_def_cfa: |
| state->cfa.reg = get_uleb128(&ptr.p8, end); |
| unw_debug("cfa_def_cfa: r%lu ", state->cfa.reg); |
| fallthrough; |
| case DW_CFA_def_cfa_offset: |
| state->cfa.offs = get_uleb128(&ptr.p8, end); |
| unw_debug("cfa_def_cfa_offset: 0x%lx ", |
| state->cfa.offs); |
| break; |
| case DW_CFA_def_cfa_sf: |
| state->cfa.reg = get_uleb128(&ptr.p8, end); |
| fallthrough; |
| case DW_CFA_def_cfa_offset_sf: |
| state->cfa.offs = get_sleb128(&ptr.p8, end) |
| * state->dataAlign; |
| break; |
| case DW_CFA_def_cfa_register: |
| unw_debug("cfa_def_cfa_register: "); |
| state->cfa.reg = get_uleb128(&ptr.p8, end); |
| break; |
| /*todo case DW_CFA_def_cfa_expression: */ |
| /*todo case DW_CFA_expression: */ |
| /*todo case DW_CFA_val_expression: */ |
| case DW_CFA_GNU_args_size: |
| get_uleb128(&ptr.p8, end); |
| break; |
| case DW_CFA_GNU_negative_offset_extended: |
| value = get_uleb128(&ptr.p8, end); |
| set_rule(value, |
| Memory, |
| (uleb128_t) 0 - get_uleb128(&ptr.p8, |
| end), |
| state); |
| break; |
| case DW_CFA_GNU_window_save: |
| default: |
| unw_debug("UNKNOWN OPCODE 0x%x\n", opcode); |
| result = 0; |
| break; |
| } |
| break; |
| case 1: |
| unw_debug("\ncfa_adv_loc: "); |
| result = advance_loc(*ptr.p8++ & 0x3f, state); |
| break; |
| case 2: |
| unw_debug("cfa_offset: "); |
| value = *ptr.p8++ & 0x3f; |
| set_rule(value, Memory, get_uleb128(&ptr.p8, end), |
| state); |
| break; |
| case 3: |
| unw_debug("cfa_restore: "); |
| set_rule(*ptr.p8++ & 0x3f, Nowhere, 0, state); |
| break; |
| } |
| |
| if (ptr.p8 > end) |
| result = 0; |
| if (result && targetLoc != 0 && targetLoc < state->loc) |
| return 1; |
| } |
| |
| return result && ptr.p8 == end && (targetLoc == 0 || ( |
| /*todo While in theory this should apply, gcc in practice omits |
| everything past the function prolog, and hence the location |
| never reaches the end of the function. |
| targetLoc < state->loc && */ state->label == NULL)); |
| } |
| |
| /* Unwind to previous to frame. Returns 0 if successful, negative |
| * number in case of an error. */ |
| int arc_unwind(struct unwind_frame_info *frame) |
| { |
| #define FRAME_REG(r, t) (((t *)frame)[reg_info[r].offs]) |
| const u32 *fde = NULL, *cie = NULL; |
| const u8 *ptr = NULL, *end = NULL; |
| unsigned long pc = UNW_PC(frame) - frame->call_frame; |
| unsigned long startLoc = 0, endLoc = 0, cfa; |
| unsigned i; |
| signed ptrType = -1; |
| uleb128_t retAddrReg = 0; |
| const struct unwind_table *table; |
| struct unwind_state state; |
| unsigned long *fptr; |
| unsigned long addr; |
| |
| unw_debug("\n\nUNWIND FRAME:\n"); |
| unw_debug("PC: 0x%lx BLINK: 0x%lx, SP: 0x%lx, FP: 0x%x\n", |
| UNW_PC(frame), UNW_BLINK(frame), UNW_SP(frame), |
| UNW_FP(frame)); |
| |
| if (UNW_PC(frame) == 0) |
| return -EINVAL; |
| |
| #ifdef UNWIND_DEBUG |
| { |
| unsigned long *sptr = (unsigned long *)UNW_SP(frame); |
| unw_debug("\nStack Dump:\n"); |
| for (i = 0; i < 20; i++, sptr++) |
| unw_debug("0x%p: 0x%lx\n", sptr, *sptr); |
| unw_debug("\n"); |
| } |
| #endif |
| |
| table = find_table(pc); |
| if (table != NULL |
| && !(table->size & (sizeof(*fde) - 1))) { |
| const u8 *hdr = table->header; |
| unsigned long tableSize; |
| |
| smp_rmb(); |
| if (hdr && hdr[0] == 1) { |
| switch (hdr[3] & DW_EH_PE_FORM) { |
| case DW_EH_PE_native: |
| tableSize = sizeof(unsigned long); |
| break; |
| case DW_EH_PE_data2: |
| tableSize = 2; |
| break; |
| case DW_EH_PE_data4: |
| tableSize = 4; |
| break; |
| case DW_EH_PE_data8: |
| tableSize = 8; |
| break; |
| default: |
| tableSize = 0; |
| break; |
| } |
| ptr = hdr + 4; |
| end = hdr + table->hdrsz; |
| if (tableSize && read_pointer(&ptr, end, hdr[1]) |
| == (unsigned long)table->address |
| && (i = read_pointer(&ptr, end, hdr[2])) > 0 |
| && i == (end - ptr) / (2 * tableSize) |
| && !((end - ptr) % (2 * tableSize))) { |
| do { |
| const u8 *cur = |
| ptr + (i / 2) * (2 * tableSize); |
| |
| startLoc = read_pointer(&cur, |
| cur + tableSize, |
| hdr[3]); |
| if (pc < startLoc) |
| i /= 2; |
| else { |
| ptr = cur - tableSize; |
| i = (i + 1) / 2; |
| } |
| } while (startLoc && i > 1); |
| if (i == 1 |
| && (startLoc = read_pointer(&ptr, |
| ptr + tableSize, |
| hdr[3])) != 0 |
| && pc >= startLoc) |
| fde = (void *)read_pointer(&ptr, |
| ptr + |
| tableSize, |
| hdr[3]); |
| } |
| } |
| |
| if (fde != NULL) { |
| cie = cie_for_fde(fde, table); |
| ptr = (const u8 *)(fde + 2); |
| if (cie != NULL |
| && cie != &bad_cie |
| && cie != ¬_fde |
| && (ptrType = fde_pointer_type(cie)) >= 0 |
| && read_pointer(&ptr, |
| (const u8 *)(fde + 1) + *fde, |
| ptrType) == startLoc) { |
| if (!(ptrType & DW_EH_PE_indirect)) |
| ptrType &= |
| DW_EH_PE_FORM | DW_EH_PE_signed; |
| endLoc = |
| startLoc + read_pointer(&ptr, |
| (const u8 *)(fde + |
| 1) + |
| *fde, ptrType); |
| if (pc >= endLoc) { |
| fde = NULL; |
| cie = NULL; |
| } |
| } else { |
| fde = NULL; |
| cie = NULL; |
| } |
| } |
| } |
| if (cie != NULL) { |
| memset(&state, 0, sizeof(state)); |
| state.cieEnd = ptr; /* keep here temporarily */ |
| ptr = (const u8 *)(cie + 2); |
| end = (const u8 *)(cie + 1) + *cie; |
| frame->call_frame = 1; |
| if (*++ptr) { |
| /* check if augmentation size is first (thus present) */ |
| if (*ptr == 'z') { |
| while (++ptr < end && *ptr) { |
| switch (*ptr) { |
| /* chk for ignorable or already handled |
| * nul-terminated augmentation string */ |
| case 'L': |
| case 'P': |
| case 'R': |
| continue; |
| case 'S': |
| frame->call_frame = 0; |
| continue; |
| default: |
| break; |
| } |
| break; |
| } |
| } |
| if (ptr >= end || *ptr) |
| cie = NULL; |
| } |
| ++ptr; |
| } |
| if (cie != NULL) { |
| /* get code alignment factor */ |
| state.codeAlign = get_uleb128(&ptr, end); |
| /* get data alignment factor */ |
| state.dataAlign = get_sleb128(&ptr, end); |
| if (state.codeAlign == 0 || state.dataAlign == 0 || ptr >= end) |
| cie = NULL; |
| else { |
| retAddrReg = |
| state.version <= 1 ? *ptr++ : get_uleb128(&ptr, |
| end); |
| unw_debug("CIE Frame Info:\n"); |
| unw_debug("return Address register 0x%lx\n", |
| retAddrReg); |
| unw_debug("data Align: %ld\n", state.dataAlign); |
| unw_debug("code Align: %lu\n", state.codeAlign); |
| /* skip augmentation */ |
| if (((const char *)(cie + 2))[1] == 'z') { |
| uleb128_t augSize = get_uleb128(&ptr, end); |
| |
| ptr += augSize; |
| } |
| if (ptr > end || retAddrReg >= ARRAY_SIZE(reg_info) |
| || REG_INVALID(retAddrReg) |
| || reg_info[retAddrReg].width != |
| sizeof(unsigned long)) |
| cie = NULL; |
| } |
| } |
| if (cie != NULL) { |
| state.cieStart = ptr; |
| ptr = state.cieEnd; |
| state.cieEnd = end; |
| end = (const u8 *)(fde + 1) + *fde; |
| /* skip augmentation */ |
| if (((const char *)(cie + 2))[1] == 'z') { |
| uleb128_t augSize = get_uleb128(&ptr, end); |
| |
| if ((ptr += augSize) > end) |
| fde = NULL; |
| } |
| } |
| if (cie == NULL || fde == NULL) { |
| #ifdef CONFIG_FRAME_POINTER |
| unsigned long top, bottom; |
| |
| top = STACK_TOP_UNW(frame->task); |
| bottom = STACK_BOTTOM_UNW(frame->task); |
| #if FRAME_RETADDR_OFFSET < 0 |
| if (UNW_SP(frame) < top && UNW_FP(frame) <= UNW_SP(frame) |
| && bottom < UNW_FP(frame) |
| #else |
| if (UNW_SP(frame) > top && UNW_FP(frame) >= UNW_SP(frame) |
| && bottom > UNW_FP(frame) |
| #endif |
| && !((UNW_SP(frame) | UNW_FP(frame)) |
| & (sizeof(unsigned long) - 1))) { |
| unsigned long link; |
| |
| if (!__get_user(link, (unsigned long *) |
| (UNW_FP(frame) + FRAME_LINK_OFFSET)) |
| #if FRAME_RETADDR_OFFSET < 0 |
| && link > bottom && link < UNW_FP(frame) |
| #else |
| && link > UNW_FP(frame) && link < bottom |
| #endif |
| && !(link & (sizeof(link) - 1)) |
| && !__get_user(UNW_PC(frame), |
| (unsigned long *)(UNW_FP(frame) |
| + FRAME_RETADDR_OFFSET))) |
| { |
| UNW_SP(frame) = |
| UNW_FP(frame) + FRAME_RETADDR_OFFSET |
| #if FRAME_RETADDR_OFFSET < 0 |
| - |
| #else |
| + |
| #endif |
| sizeof(UNW_PC(frame)); |
| UNW_FP(frame) = link; |
| return 0; |
| } |
| } |
| #endif |
| return -ENXIO; |
| } |
| state.org = startLoc; |
| memcpy(&state.cfa, &badCFA, sizeof(state.cfa)); |
| |
| unw_debug("\nProcess instructions\n"); |
| |
| /* process instructions |
| * For ARC, we optimize by having blink(retAddrReg) with |
| * the sameValue in the leaf function, so we should not check |
| * state.regs[retAddrReg].where == Nowhere |
| */ |
| if (!processCFI(ptr, end, pc, ptrType, &state) |
| || state.loc > endLoc |
| /* || state.regs[retAddrReg].where == Nowhere */ |
| || state.cfa.reg >= ARRAY_SIZE(reg_info) |
| || reg_info[state.cfa.reg].width != sizeof(unsigned long) |
| || state.cfa.offs % sizeof(unsigned long)) |
| return -EIO; |
| |
| #ifdef UNWIND_DEBUG |
| unw_debug("\n"); |
| |
| unw_debug("\nRegister State Based on the rules parsed from FDE:\n"); |
| for (i = 0; i < ARRAY_SIZE(state.regs); ++i) { |
| |
| if (REG_INVALID(i)) |
| continue; |
| |
| switch (state.regs[i].where) { |
| case Nowhere: |
| break; |
| case Memory: |
| unw_debug(" r%d: c(%lu),", i, state.regs[i].value); |
| break; |
| case Register: |
| unw_debug(" r%d: r(%lu),", i, state.regs[i].value); |
| break; |
| case Value: |
| unw_debug(" r%d: v(%lu),", i, state.regs[i].value); |
| break; |
| } |
| } |
| |
| unw_debug("\n"); |
| #endif |
| |
| /* update frame */ |
| if (frame->call_frame |
| && !UNW_DEFAULT_RA(state.regs[retAddrReg], state.dataAlign)) |
| frame->call_frame = 0; |
| cfa = FRAME_REG(state.cfa.reg, unsigned long) + state.cfa.offs; |
| startLoc = min_t(unsigned long, UNW_SP(frame), cfa); |
| endLoc = max_t(unsigned long, UNW_SP(frame), cfa); |
| if (STACK_LIMIT(startLoc) != STACK_LIMIT(endLoc)) { |
| startLoc = min(STACK_LIMIT(cfa), cfa); |
| endLoc = max(STACK_LIMIT(cfa), cfa); |
| } |
| |
| unw_debug("\nCFA reg: 0x%lx, offset: 0x%lx => 0x%lx\n", |
| state.cfa.reg, state.cfa.offs, cfa); |
| |
| for (i = 0; i < ARRAY_SIZE(state.regs); ++i) { |
| if (REG_INVALID(i)) { |
| if (state.regs[i].where == Nowhere) |
| continue; |
| return -EIO; |
| } |
| switch (state.regs[i].where) { |
| default: |
| break; |
| case Register: |
| if (state.regs[i].value >= ARRAY_SIZE(reg_info) |
| || REG_INVALID(state.regs[i].value) |
| || reg_info[i].width > |
| reg_info[state.regs[i].value].width) |
| return -EIO; |
| switch (reg_info[state.regs[i].value].width) { |
| case sizeof(u8): |
| state.regs[i].value = |
| FRAME_REG(state.regs[i].value, const u8); |
| break; |
| case sizeof(u16): |
| state.regs[i].value = |
| FRAME_REG(state.regs[i].value, const u16); |
| break; |
| case sizeof(u32): |
| state.regs[i].value = |
| FRAME_REG(state.regs[i].value, const u32); |
| break; |
| #ifdef CONFIG_64BIT |
| case sizeof(u64): |
| state.regs[i].value = |
| FRAME_REG(state.regs[i].value, const u64); |
| break; |
| #endif |
| default: |
| return -EIO; |
| } |
| break; |
| } |
| } |
| |
| unw_debug("\nRegister state after evaluation with realtime Stack:\n"); |
| fptr = (unsigned long *)(&frame->regs); |
| for (i = 0; i < ARRAY_SIZE(state.regs); ++i, fptr++) { |
| |
| if (REG_INVALID(i)) |
| continue; |
| switch (state.regs[i].where) { |
| case Nowhere: |
| if (reg_info[i].width != sizeof(UNW_SP(frame)) |
| || &FRAME_REG(i, __typeof__(UNW_SP(frame))) |
| != &UNW_SP(frame)) |
| continue; |
| UNW_SP(frame) = cfa; |
| break; |
| case Register: |
| switch (reg_info[i].width) { |
| case sizeof(u8): |
| FRAME_REG(i, u8) = state.regs[i].value; |
| break; |
| case sizeof(u16): |
| FRAME_REG(i, u16) = state.regs[i].value; |
| break; |
| case sizeof(u32): |
| FRAME_REG(i, u32) = state.regs[i].value; |
| break; |
| #ifdef CONFIG_64BIT |
| case sizeof(u64): |
| FRAME_REG(i, u64) = state.regs[i].value; |
| break; |
| #endif |
| default: |
| return -EIO; |
| } |
| break; |
| case Value: |
| if (reg_info[i].width != sizeof(unsigned long)) |
| return -EIO; |
| FRAME_REG(i, unsigned long) = cfa + state.regs[i].value |
| * state.dataAlign; |
| break; |
| case Memory: |
| addr = cfa + state.regs[i].value * state.dataAlign; |
| |
| if ((state.regs[i].value * state.dataAlign) |
| % sizeof(unsigned long) |
| || addr < startLoc |
| || addr + sizeof(unsigned long) < addr |
| || addr + sizeof(unsigned long) > endLoc) |
| return -EIO; |
| |
| switch (reg_info[i].width) { |
| case sizeof(u8): |
| __get_user(FRAME_REG(i, u8), |
| (u8 __user *)addr); |
| break; |
| case sizeof(u16): |
| __get_user(FRAME_REG(i, u16), |
| (u16 __user *)addr); |
| break; |
| case sizeof(u32): |
| __get_user(FRAME_REG(i, u32), |
| (u32 __user *)addr); |
| break; |
| #ifdef CONFIG_64BIT |
| case sizeof(u64): |
| __get_user(FRAME_REG(i, u64), |
| (u64 __user *)addr); |
| break; |
| #endif |
| default: |
| return -EIO; |
| } |
| |
| break; |
| } |
| unw_debug("r%d: 0x%lx ", i, *fptr); |
| } |
| |
| return 0; |
| #undef FRAME_REG |
| } |
| EXPORT_SYMBOL(arc_unwind); |