diff options
Diffstat (limited to 'arch/arc/kernel/unwind.c')
| -rw-r--r-- | arch/arc/kernel/unwind.c | 1322 |
1 files changed, 1322 insertions, 0 deletions
diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c new file mode 100644 index 000000000..9cf2ee8b4 --- /dev/null +++ b/arch/arc/kernel/unwind.c @@ -0,0 +1,1322 @@ +/* + * Copyright (C) 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + * Copyright (C) 2002-2006 Novell, Inc. + * Jan Beulich <jbeulich@novell.com> + * + * 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 <linux/sched.h> +#include <linux/module.h> +#include <linux/bootmem.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) \ + % 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 + +#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 __alloc_bootmem_nopanic(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) +{ + 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);*/ + + 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 + 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); + /*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_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 */ +#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); |