+++ /dev/null
-/*
- * Copyright (C) 2002-2006 Novell, Inc.
- * Jan Beulich <jbeulich@novell.com>
- * This code is released under version 2 of the GNU GPL.
- *
- * 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/unwind.h>
-#include <linux/module.h>
-#include <linux/bootmem.h>
-#include <linux/sort.h>
-#include <linux/stop_machine.h>
-#include <linux/uaccess.h>
-#include <asm/sections.h>
-#include <asm/uaccess.h>
-#include <asm/unaligned.h>
-
-extern const char __start_unwind[], __end_unwind[];
-extern const u8 __start_unwind_hdr[], __end_unwind_hdr[];
-
-#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;
-#define sleb128abs __builtin_labs
-
-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 unsigned unwind_debug;
-static int __init unwind_debug_setup(char *s)
-{
- unwind_debug = simple_strtoul(s, NULL, 0);
- return 1;
-}
-__setup("unwind_debug=", unwind_debug_setup);
-#define dprintk(lvl, fmt, args...) \
- ((void)(lvl > unwind_debug \
- || printk(KERN_DEBUG "unwind: " fmt "\n", ##args)))
-
-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,
- unsigned long text_base,
- unsigned long data_base);
-
-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], 0, 0)
- != table_start
- || !read_pointer(&ptr, end, header_start[2], 0, 0)
- || !read_pointer(&ptr, end, header_start[3], 0,
- (unsigned long)header_start)
- || !read_pointer(&ptr, end, header_start[3], 0,
- (unsigned long)header_start))
- header_start = NULL;
- table->hdrsz = header_size;
- smp_wmb();
- table->header = header_start;
- table->link = NULL;
- table->name = name;
-}
-
-void __init unwind_init(void)
-{
- init_unwind_table(&root_table, "kernel",
- _text, _end - _text,
- NULL, 0,
- __start_unwind, __end_unwind - __start_unwind,
- __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)
- printk(KERN_WARNING ".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
- || (ptrType = fde_pointer_type(cie)) < 0)
- return;
- ptr = (const u8 *)(fde + 2);
- if (!read_pointer(&ptr,
- (const u8 *)(fde + 1) + *fde,
- ptrType, 0, 0))
- return;
- ++n;
- }
-
- if (tableSize || !n)
- return;
-
- hdrSize = 4 + sizeof(unsigned long) + sizeof(unsigned int)
- + 2 * n * sizeof(unsigned long);
- dprintk(2, "Binary lookup table size for %s: %lu bytes", table->name, hdrSize);
- 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);
-
- if (!fde[1])
- 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), 0, 0);
- 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 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);
-
- 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;
- stop_machine_run(unlink_table, &info, NR_CPUS);
-
- if (info.table)
- 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])
- 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);
- if (*cie <= sizeof(*cie) + 4
- || *cie >= fde[1] - sizeof(*fde)
- || (*cie & (sizeof(*cie) - 1))
- || cie[1])
- 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 text_base,
- unsigned long data_base)
-{
- 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) {
- dprintk(1, "Invalid pointer encoding %02X (%p,%p).", ptrType, *pLoc, end);
- return 0;
- }
- ptr.p8 = *pLoc;
- switch(ptrType & DW_EH_PE_FORM) {
- case DW_EH_PE_data2:
- if (end < (const void *)(ptr.p16u + 1)) {
- dprintk(1, "Data16 overrun (%p,%p).", ptr.p8, end);
- return 0;
- }
- if(ptrType & DW_EH_PE_signed)
- value = get_unaligned(ptr.p16s++);
- else
- value = get_unaligned(ptr.p16u++);
- break;
- case DW_EH_PE_data4:
-#ifdef CONFIG_64BIT
- if (end < (const void *)(ptr.p32u + 1)) {
- dprintk(1, "Data32 overrun (%p,%p).", ptr.p8, end);
- 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)) {
- dprintk(1, "DataUL overrun (%p,%p).", ptr.p8, end);
- return 0;
- }
- value = get_unaligned(ptr.pul++);
- break;
- case DW_EH_PE_leb128:
- BUILD_BUG_ON(sizeof(uleb128_t) > sizeof(value));
- value = ptrType & DW_EH_PE_signed
- ? get_sleb128(&ptr.p8, end)
- : get_uleb128(&ptr.p8, end);
- if ((const void *)ptr.p8 > end) {
- dprintk(1, "DataLEB overrun (%p,%p).", ptr.p8, end);
- return 0;
- }
- break;
- default:
- dprintk(2, "Cannot decode pointer type %02X (%p,%p).",
- ptrType, ptr.p8, end);
- return 0;
- }
- switch(ptrType & DW_EH_PE_ADJUST) {
- case DW_EH_PE_abs:
- break;
- case DW_EH_PE_pcrel:
- value += (unsigned long)*pLoc;
- break;
- case DW_EH_PE_textrel:
- if (likely(text_base)) {
- value += text_base;
- break;
- }
- dprintk(2, "Text-relative encoding %02X (%p,%p), but zero text base.",
- ptrType, *pLoc, end);
- return 0;
- case DW_EH_PE_datarel:
- if (likely(data_base)) {
- value += data_base;
- break;
- }
- dprintk(2, "Data-relative encoding %02X (%p,%p), but zero data base.",
- ptrType, *pLoc, end);
- return 0;
- default:
- dprintk(2, "Cannot adjust pointer type %02X (%p,%p).",
- ptrType, *pLoc, end);
- return 0;
- }
- if ((ptrType & DW_EH_PE_indirect)
- && probe_kernel_address((unsigned long *)value, value)) {
- dprintk(1, "Cannot read indirect value %lx (%p,%p).",
- value, *pLoc, end);
- return 0;
- }
- *pLoc = ptr.p8;
-
- return value;
-}
-
-static signed fde_pointer_type(const u32 *cie)
-{
- const u8 *ptr = (const u8 *)(cie + 2);
- unsigned version = *ptr;
-
- if (version != 1)
- return -1; /* unsupported */
- if (*++ptr) {
- const char *aug;
- const u8 *end = (const u8 *)(cie + 1) + *cie;
- uleb128_t len;
-
- /* check if augmentation size is first (and thus present) */
- if (*ptr != 'z')
- return -1;
- /* check if augmentation string is nul-terminated */
- if ((ptr = memchr(aug = (const void *)ptr, 0, end - ptr)) == NULL)
- return -1;
- ++ptr; /* skip terminator */
- get_uleb128(&ptr, end); /* skip code alignment */
- get_sleb128(&ptr, end); /* skip data alignment */
- /* skip return address column */
- version <= 1 ? (void)++ptr : (void)get_uleb128(&ptr, end);
- len = get_uleb128(&ptr, end); /* augmentation length */
- if (ptr + len < ptr || ptr + len > end)
- return -1;
- end = ptr + len;
- while (*++aug) {
- if (ptr >= end)
- return -1;
- switch(*aug) {
- case 'L':
- ++ptr;
- break;
- case 'P': {
- signed ptrType = *ptr++;
-
- if (!read_pointer(&ptr, end, ptrType, 0, 0)
- || ptr > end)
- return -1;
- }
- break;
- case 'R':
- return *ptr;
- default:
- return -1;
- }
- }
- }
- return DW_EH_PE_native|DW_EH_PE_abs;
-}
-
-static int advance_loc(unsigned long delta, struct unwind_state *state)
-{
- state->loc += delta * state->codeAlign;
-
- return delta > 0;
-}
-
-static void set_rule(uleb128_t reg,
- enum item_location where,
- uleb128_t value,
- struct unwind_state *state)
-{
- if (reg < ARRAY_SIZE(state->regs)) {
- state->regs[reg].where = where;
- state->regs[reg].value = value;
- }
-}
-
-static int processCFI(const u8 *start,
- const u8 *end,
- unsigned long targetLoc,
- signed ptrType,
- struct unwind_state *state)
-{
- union {
- const u8 *p8;
- const u16 *p16;
- const u32 *p32;
- } ptr;
- int result = 1;
-
- if (start != state->cieStart) {
- state->loc = state->org;
- result = processCFI(state->cieStart, state->cieEnd, 0, ptrType, state);
- if (targetLoc == 0 && state->label == NULL)
- return result;
- }
- for (ptr.p8 = start; result && ptr.p8 < end; ) {
- switch(*ptr.p8 >> 6) {
- uleb128_t value;
-
- case 0:
- switch(*ptr.p8++) {
- case DW_CFA_nop:
- break;
- case DW_CFA_set_loc:
- state->loc = read_pointer(&ptr.p8, end, ptrType, 0, 0);
- if (state->loc == 0)
- result = 0;
- break;
- case DW_CFA_advance_loc1:
- result = ptr.p8 < end && advance_loc(*ptr.p8++, state);
- break;
- case DW_CFA_advance_loc2:
- result = ptr.p8 <= end + 2
- && advance_loc(*ptr.p16++, state);
- break;
- case DW_CFA_advance_loc4:
- result = ptr.p8 <= end + 4
- && advance_loc(*ptr.p32++, state);
- break;
- case DW_CFA_offset_extended:
- value = get_uleb128(&ptr.p8, end);
- set_rule(value, Memory, get_uleb128(&ptr.p8, end), state);
- break;
- case DW_CFA_val_offset:
- value = get_uleb128(&ptr.p8, end);
- set_rule(value, Value, get_uleb128(&ptr.p8, end), state);
- break;
- case DW_CFA_offset_extended_sf:
- value = get_uleb128(&ptr.p8, end);
- set_rule(value, Memory, get_sleb128(&ptr.p8, end), state);
- break;
- case DW_CFA_val_offset_sf:
- value = get_uleb128(&ptr.p8, end);
- set_rule(value, Value, get_sleb128(&ptr.p8, end), state);
- break;
- case DW_CFA_restore_extended:
- case DW_CFA_undefined:
- case DW_CFA_same_value:
- set_rule(get_uleb128(&ptr.p8, end), Nowhere, 0, state);
- break;
- case DW_CFA_register:
- value = get_uleb128(&ptr.p8, end);
- set_rule(value,
- Register,
- get_uleb128(&ptr.p8, end), state);
- break;
- case DW_CFA_remember_state:
- if (ptr.p8 == state->label) {
- state->label = NULL;
- return 1;
- }
- if (state->stackDepth >= MAX_STACK_DEPTH) {
- dprintk(1, "State stack overflow (%p,%p).", ptr.p8, end);
- return 0;
- }
- state->stack[state->stackDepth++] = ptr.p8;
- break;
- case DW_CFA_restore_state:
- if (state->stackDepth) {
- const uleb128_t loc = state->loc;
- const u8 *label = state->label;
-
- state->label = state->stack[state->stackDepth - 1];
- memcpy(&state->cfa, &badCFA, sizeof(state->cfa));
- memset(state->regs, 0, sizeof(state->regs));
- state->stackDepth = 0;
- result = processCFI(start, end, 0, ptrType, state);
- state->loc = loc;
- state->label = label;
- } else {
- dprintk(1, "State stack underflow (%p,%p).", ptr.p8, end);
- return 0;
- }
- break;
- case DW_CFA_def_cfa:
- state->cfa.reg = get_uleb128(&ptr.p8, end);
- /*nobreak*/
- case DW_CFA_def_cfa_offset:
- state->cfa.offs = get_uleb128(&ptr.p8, end);
- break;
- case DW_CFA_def_cfa_sf:
- state->cfa.reg = get_uleb128(&ptr.p8, end);
- /*nobreak*/
- case DW_CFA_def_cfa_offset_sf:
- state->cfa.offs = get_sleb128(&ptr.p8, end)
- * state->dataAlign;
- break;
- case DW_CFA_def_cfa_register:
- state->cfa.reg = get_uleb128(&ptr.p8, end);
- break;
- /*todo case DW_CFA_def_cfa_expression: */
- /*todo case DW_CFA_expression: */
- /*todo case DW_CFA_val_expression: */
- case DW_CFA_GNU_args_size:
- get_uleb128(&ptr.p8, end);
- break;
- case DW_CFA_GNU_negative_offset_extended:
- value = get_uleb128(&ptr.p8, end);
- set_rule(value,
- Memory,
- (uleb128_t)0 - get_uleb128(&ptr.p8, end), state);
- break;
- case DW_CFA_GNU_window_save:
- default:
- dprintk(1, "Unrecognized CFI op %02X (%p,%p).", ptr.p8[-1], ptr.p8 - 1, end);
- result = 0;
- break;
- }
- break;
- case 1:
- result = advance_loc(*ptr.p8++ & 0x3f, state);
- break;
- case 2:
- value = *ptr.p8++ & 0x3f;
- set_rule(value, Memory, get_uleb128(&ptr.p8, end), state);
- break;
- case 3:
- set_rule(*ptr.p8++ & 0x3f, Nowhere, 0, state);
- break;
- }
- if (ptr.p8 > end) {
- dprintk(1, "Data overrun (%p,%p).", ptr.p8, end);
- result = 0;
- }
- if (result && targetLoc != 0 && targetLoc < state->loc)
- return 1;
- }
-
- if (result && ptr.p8 < end)
- dprintk(1, "Data underrun (%p,%p).", ptr.p8, end);
-
- return result
- && ptr.p8 == end
- && (targetLoc == 0
- || (/*todo While in theory this should apply, gcc in practice omits
- everything past the function prolog, and hence the location
- never reaches the end of the function.
- targetLoc < state->loc &&*/ state->label == NULL));
-}
-
-/* Unwind to previous to frame. Returns 0 if successful, negative
- * number in case of an error. */
-int unwind(struct unwind_frame_info *frame)
-{
-#define FRAME_REG(r, t) (((t *)frame)[reg_info[r].offs])
- const u32 *fde = NULL, *cie = NULL;
- const u8 *ptr = NULL, *end = NULL;
- unsigned long pc = UNW_PC(frame) - frame->call_frame, sp;
- unsigned long startLoc = 0, endLoc = 0, cfa;
- unsigned i;
- signed ptrType = -1;
- uleb128_t retAddrReg = 0;
- const struct unwind_table *table;
- struct unwind_state state;
-
- if (UNW_PC(frame) == 0)
- return -EINVAL;
- if ((table = find_table(pc)) != NULL
- && !(table->size & (sizeof(*fde) - 1))) {
- const u8 *hdr = table->header;
- unsigned long tableSize;
-
- smp_rmb();
- if (hdr && hdr[0] == 1) {
- switch(hdr[3] & DW_EH_PE_FORM) {
- case DW_EH_PE_native: tableSize = sizeof(unsigned long); break;
- case DW_EH_PE_data2: tableSize = 2; break;
- case DW_EH_PE_data4: tableSize = 4; break;
- case DW_EH_PE_data8: tableSize = 8; break;
- default: tableSize = 0; break;
- }
- ptr = hdr + 4;
- end = hdr + table->hdrsz;
- if (tableSize
- && read_pointer(&ptr, end, hdr[1], 0, 0)
- == (unsigned long)table->address
- && (i = read_pointer(&ptr, end, hdr[2], 0, 0)) > 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], 0,
- (unsigned long)hdr);
- 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,
- (unsigned long)hdr)) != 0
- && pc >= startLoc)
- fde = (void *)read_pointer(&ptr,
- ptr + tableSize,
- hdr[3], 0,
- (unsigned long)hdr);
- }
- }
- if(hdr && !fde)
- dprintk(3, "Binary lookup for %lx failed.", pc);
-
- 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, 0, 0) == 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, 0, 0);
- if(pc >= endLoc)
- fde = NULL;
- } else
- fde = NULL;
- if(!fde)
- dprintk(1, "Binary lookup result for %lx discarded.", pc);
- }
- 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, 0, 0);
- 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, 0, 0);
- if (pc >= startLoc && pc < endLoc)
- break;
- }
- if(!fde)
- dprintk(3, "Linear lookup for %lx failed.", pc);
- }
- }
- if (cie != NULL) {
- memset(&state, 0, sizeof(state));
- state.cieEnd = ptr; /* keep here temporarily */
- ptr = (const u8 *)(cie + 2);
- end = (const u8 *)(cie + 1) + *cie;
- frame->call_frame = 1;
- if ((state.version = *ptr) != 1)
- cie = NULL; /* unsupported version */
- else if (*++ptr) {
- /* check if augmentation size is first (and thus present) */
- if (*ptr == 'z') {
- while (++ptr < end && *ptr) {
- switch(*ptr) {
- /* check for ignorable (or already handled)
- * nul-terminated augmentation string */
- case 'L':
- case 'P':
- case 'R':
- continue;
- case 'S':
- frame->call_frame = 0;
- continue;
- default:
- break;
- }
- break;
- }
- }
- if (ptr >= end || *ptr)
- cie = NULL;
- }
- if(!cie)
- dprintk(1, "CIE unusable (%p,%p).", ptr, end);
- ++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 if (UNW_PC(frame) % state.codeAlign
- || UNW_SP(frame) % sleb128abs(state.dataAlign)) {
- dprintk(1, "Input pointer(s) misaligned (%lx,%lx).",
- UNW_PC(frame), UNW_SP(frame));
- return -EPERM;
- } else {
- retAddrReg = state.version <= 1 ? *ptr++ : get_uleb128(&ptr, end);
- /* 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)
- dprintk(1, "CIE validation failed (%p,%p).", ptr, end);
- }
- 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(!fde)
- dprintk(1, "FDE validation failed (%p,%p).", ptr, end);
- }
- if (cie == NULL || fde == NULL) {
-#ifdef CONFIG_FRAME_POINTER
- unsigned long top, bottom;
-
- if ((UNW_SP(frame) | UNW_FP(frame)) % sizeof(unsigned long))
- return -EPERM;
- top = STACK_TOP(frame->task);
- bottom = STACK_BOTTOM(frame->task);
-# if FRAME_RETADDR_OFFSET < 0
- if (UNW_SP(frame) < top
- && UNW_FP(frame) <= UNW_SP(frame)
- && bottom < UNW_FP(frame)
-# else
- if (UNW_SP(frame) > top
- && UNW_FP(frame) >= UNW_SP(frame)
- && bottom > UNW_FP(frame)
-# endif
- && !((UNW_SP(frame) | UNW_FP(frame))
- & (sizeof(unsigned long) - 1))) {
- unsigned long link;
-
- if (!probe_kernel_address(
- (unsigned long *)(UNW_FP(frame)
- + FRAME_LINK_OFFSET),
- link)
-# if FRAME_RETADDR_OFFSET < 0
- && link > bottom && link < UNW_FP(frame)
-# else
- && link > UNW_FP(frame) && link < bottom
-# endif
- && !(link & (sizeof(link) - 1))
- && !probe_kernel_address(
- (unsigned long *)(UNW_FP(frame)
- + FRAME_RETADDR_OFFSET), UNW_PC(frame))) {
- UNW_SP(frame) = UNW_FP(frame) + FRAME_RETADDR_OFFSET
-# if FRAME_RETADDR_OFFSET < 0
- -
-# else
- +
-# endif
- sizeof(UNW_PC(frame));
- UNW_FP(frame) = link;
- return 0;
- }
- }
-#endif
- return -ENXIO;
- }
- state.org = startLoc;
- memcpy(&state.cfa, &badCFA, sizeof(state.cfa));
- /* process instructions */
- if (!processCFI(ptr, end, pc, ptrType, &state)
- || state.loc > endLoc
- || state.regs[retAddrReg].where == Nowhere
- || state.cfa.reg >= ARRAY_SIZE(reg_info)
- || reg_info[state.cfa.reg].width != sizeof(unsigned long)
- || FRAME_REG(state.cfa.reg, unsigned long) % sizeof(unsigned long)
- || state.cfa.offs % sizeof(unsigned long)) {
- dprintk(1, "Unusable unwind info (%p,%p).", ptr, end);
- return -EIO;
- }
- /* update frame */
-#ifndef CONFIG_AS_CFI_SIGNAL_FRAME
- if(frame->call_frame
- && !UNW_DEFAULT_RA(state.regs[retAddrReg], state.dataAlign))
- frame->call_frame = 0;
-#endif
- cfa = FRAME_REG(state.cfa.reg, unsigned long) + state.cfa.offs;
- startLoc = min((unsigned long)UNW_SP(frame), cfa);
- endLoc = max((unsigned long)UNW_SP(frame), cfa);
- if (STACK_LIMIT(startLoc) != STACK_LIMIT(endLoc)) {
- startLoc = min(STACK_LIMIT(cfa), cfa);
- endLoc = max(STACK_LIMIT(cfa), cfa);
- }
-#ifndef CONFIG_64BIT
-# define CASES CASE(8); CASE(16); CASE(32)
-#else
-# define CASES CASE(8); CASE(16); CASE(32); CASE(64)
-#endif
- pc = UNW_PC(frame);
- sp = UNW_SP(frame);
- for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
- if (REG_INVALID(i)) {
- if (state.regs[i].where == Nowhere)
- continue;
- dprintk(1, "Cannot restore register %u (%d).",
- i, state.regs[i].where);
- 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) {
- dprintk(1, "Cannot restore register %u from register %lu.",
- i, state.regs[i].value);
- return -EIO;
- }
- switch(reg_info[state.regs[i].value].width) {
-#define CASE(n) \
- case sizeof(u##n): \
- state.regs[i].value = FRAME_REG(state.regs[i].value, \
- const u##n); \
- break
- CASES;
-#undef CASE
- default:
- dprintk(1, "Unsupported register size %u (%lu).",
- reg_info[state.regs[i].value].width,
- state.regs[i].value);
- return -EIO;
- }
- break;
- }
- }
- for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
- if (REG_INVALID(i))
- continue;
- switch(state.regs[i].where) {
- case Nowhere:
- if (reg_info[i].width != sizeof(UNW_SP(frame))
- || &FRAME_REG(i, __typeof__(UNW_SP(frame)))
- != &UNW_SP(frame))
- continue;
- UNW_SP(frame) = cfa;
- break;
- case Register:
- switch(reg_info[i].width) {
-#define CASE(n) case sizeof(u##n): \
- FRAME_REG(i, u##n) = state.regs[i].value; \
- break
- CASES;
-#undef CASE
- default:
- dprintk(1, "Unsupported register size %u (%u).",
- reg_info[i].width, i);
- return -EIO;
- }
- break;
- case Value:
- if (reg_info[i].width != sizeof(unsigned long)) {
- dprintk(1, "Unsupported value size %u (%u).",
- reg_info[i].width, i);
- return -EIO;
- }
- FRAME_REG(i, unsigned long) = cfa + state.regs[i].value
- * state.dataAlign;
- break;
- case Memory: {
- unsigned long addr = cfa + state.regs[i].value
- * state.dataAlign;
-
- if ((state.regs[i].value * state.dataAlign)
- % sizeof(unsigned long)
- || addr < startLoc
- || addr + sizeof(unsigned long) < addr
- || addr + sizeof(unsigned long) > endLoc) {
- dprintk(1, "Bad memory location %lx (%lx).",
- addr, state.regs[i].value);
- return -EIO;
- }
- switch(reg_info[i].width) {
-#define CASE(n) case sizeof(u##n): \
- probe_kernel_address((u##n *)addr, FRAME_REG(i, u##n)); \
- break
- CASES;
-#undef CASE
- default:
- dprintk(1, "Unsupported memory size %u (%u).",
- reg_info[i].width, i);
- return -EIO;
- }
- }
- break;
- }
- }
-
- if (UNW_PC(frame) % state.codeAlign
- || UNW_SP(frame) % sleb128abs(state.dataAlign)) {
- dprintk(1, "Output pointer(s) misaligned (%lx,%lx).",
- UNW_PC(frame), UNW_SP(frame));
- return -EIO;
- }
- if (pc == UNW_PC(frame) && sp == UNW_SP(frame)) {
- dprintk(1, "No progress (%lx,%lx).", pc, sp);
- return -EIO;
- }
-
- return 0;
-#undef CASES
-#undef FRAME_REG
-}
-EXPORT_SYMBOL(unwind);
-
-int unwind_init_frame_info(struct unwind_frame_info *info,
- struct task_struct *tsk,
- /*const*/ struct pt_regs *regs)
-{
- info->task = tsk;
- info->call_frame = 0;
- arch_unw_init_frame_info(info, regs);
-
- return 0;
-}
-EXPORT_SYMBOL(unwind_init_frame_info);
-
-/*
- * Prepare to unwind a blocked task.
- */
-int unwind_init_blocked(struct unwind_frame_info *info,
- struct task_struct *tsk)
-{
- info->task = tsk;
- info->call_frame = 0;
- arch_unw_init_blocked(info);
-
- return 0;
-}
-EXPORT_SYMBOL(unwind_init_blocked);
-
-/*
- * Prepare to unwind the currently running thread.
- */
-int unwind_init_running(struct unwind_frame_info *info,
- asmlinkage int (*callback)(struct unwind_frame_info *,
- void *arg),
- void *arg)
-{
- info->task = current;
- info->call_frame = 0;
-
- return arch_unwind_init_running(info, callback, arg);
-}
-EXPORT_SYMBOL(unwind_init_running);
-
-/*
- * Unwind until the return pointer is in user-land (or until an error
- * occurs). Returns 0 if successful, negative number in case of
- * error.
- */
-int unwind_to_user(struct unwind_frame_info *info)
-{
- while (!arch_unw_user_mode(info)) {
- int err = unwind(info);
-
- if (err < 0)
- return err;
- }
-
- return 0;
-}
-EXPORT_SYMBOL(unwind_to_user);
projects / kernel / kernel-generic.git / commitdiff