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c33bd9aac0
linux/kernel/unwind.c
Jan Beulich c33bd9aac0 [PATCH] i386/x86-64: fall back to old-style call trace if no unwinding 
If no unwinding is possible at all for a certain exception instance,
fall back to the old style call trace instead of not showing any trace
at all.

Also, allow setting the stack trace mode at the command line.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 10:48:18 -07:00

915 lines
24 KiB
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/*
* 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/delay.h>
#include <linux/stop_machine.h>
#include <asm/sections.h>
#include <asm/uaccess.h>
#include <asm/unaligned.h>
extern char __start_unwind[], __end_unwind[];
#define MAX_STACK_DEPTH 8
#define EXTRA_INFO(f) { \
BUILD_BUG_ON_ZERO(offsetof(struct unwind_frame_info, f) \
% FIELD_SIZEOF(struct unwind_frame_info, f)) \
+ offsetof(struct unwind_frame_info, f) \
/ FIELD_SIZEOF(struct unwind_frame_info, f), \
FIELD_SIZEOF(struct unwind_frame_info, f) \
}
#define PTREGS_INFO(f) EXTRA_INFO(regs.f)
static const struct {
unsigned offs:BITS_PER_LONG / 2;
unsigned width:BITS_PER_LONG / 2;
} reg_info[] = {
UNW_REGISTER_INFO
};
#undef PTREGS_INFO
#undef EXTRA_INFO
#ifndef REG_INVALID
#define REG_INVALID(r) (reg_info[r].width == 0)
#endif
#define DW_CFA_nop 0x00
#define DW_CFA_set_loc 0x01
#define DW_CFA_advance_loc1 0x02
#define DW_CFA_advance_loc2 0x03
#define DW_CFA_advance_loc4 0x04
#define DW_CFA_offset_extended 0x05
#define DW_CFA_restore_extended 0x06
#define DW_CFA_undefined 0x07
#define DW_CFA_same_value 0x08
#define DW_CFA_register 0x09
#define DW_CFA_remember_state 0x0a
#define DW_CFA_restore_state 0x0b
#define DW_CFA_def_cfa 0x0c
#define DW_CFA_def_cfa_register 0x0d
#define DW_CFA_def_cfa_offset 0x0e
#define DW_CFA_def_cfa_expression 0x0f
#define DW_CFA_expression 0x10
#define DW_CFA_offset_extended_sf 0x11
#define DW_CFA_def_cfa_sf 0x12
#define DW_CFA_def_cfa_offset_sf 0x13
#define DW_CFA_val_offset 0x14
#define DW_CFA_val_offset_sf 0x15
#define DW_CFA_val_expression 0x16
#define DW_CFA_lo_user 0x1c
#define DW_CFA_GNU_window_save 0x2d
#define DW_CFA_GNU_args_size 0x2e
#define DW_CFA_GNU_negative_offset_extended 0x2f
#define DW_CFA_hi_user 0x3f
#define DW_EH_PE_FORM 0x07
#define DW_EH_PE_native 0x00
#define DW_EH_PE_leb128 0x01
#define DW_EH_PE_data2 0x02
#define DW_EH_PE_data4 0x03
#define DW_EH_PE_data8 0x04
#define DW_EH_PE_signed 0x08
#define DW_EH_PE_ADJUST 0x70
#define DW_EH_PE_abs 0x00
#define DW_EH_PE_pcrel 0x10
#define DW_EH_PE_textrel 0x20
#define DW_EH_PE_datarel 0x30
#define DW_EH_PE_funcrel 0x40
#define DW_EH_PE_aligned 0x50
#define DW_EH_PE_indirect 0x80
#define DW_EH_PE_omit 0xff
typedef unsigned long uleb128_t;
typedef signed long sleb128_t;
static struct unwind_table {
struct {
unsigned long pc;
unsigned long range;
} core, init;
const void *address;
unsigned long size;
struct unwind_table *link;
const char *name;
} root_table, *last_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 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)
{
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;
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);
}
/* 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);
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);
}
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 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(ptr.p16s++);
else
value = get_unaligned(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(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 *)value))
return 0;
*pLoc = ptr.p8;
return value;
}
static signed fde_pointer_type(const u32 *cie)
{
const u8 *ptr = (const u8 *)(cie + 2);
unsigned version = *ptr;
if (version != 1)
return -1; /* unsupported */
if (*++ptr) {
const char *aug;
const u8 *end = (const u8 *)(cie + 1) + *cie;
uleb128_t len;
/* check if augmentation size is first (and thus present) */
if (*ptr != 'z')
return -1;
/* check if augmentation string is nul-terminated */
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) || 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:
if ((state->loc = read_pointer(&ptr.p8, end, ptrType)) == 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)
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
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:
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)
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 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 startLoc = 0, endLoc = 0, cfa;
unsigned i;
signed ptrType = -1;
uleb128_t retAddrReg = 0;
struct unwind_table *table;
struct unwind_state state;
if (UNW_PC(frame) == 0)
return -EINVAL;
if ((table = find_table(UNW_PC(frame))) != NULL
&& !(table->size & (sizeof(*fde) - 1))) {
unsigned long tableSize = table->size;
for (fde = table->address;
tableSize > sizeof(*fde) && tableSize - sizeof(*fde) >= *fde;
tableSize -= sizeof(*fde) + *fde,
fde += 1 + *fde / sizeof(*fde)) {
if (!*fde || (*fde & (sizeof(*fde) - 1)))
break;
if (!fde[1])
continue; /* this is a CIE */
if ((fde[1] & (sizeof(*fde) - 1))
|| fde[1] > (unsigned long)(fde + 1)
- (unsigned long)table->address)
continue; /* 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]
|| (ptrType = fde_pointer_type(cie)) < 0) {
cie = NULL; /* this is not a (valid) CIE */
continue;
}
ptr = (const u8 *)(fde + 2);
startLoc = read_pointer(&ptr,
(const u8 *)(fde + 1) + *fde,
ptrType);
endLoc = startLoc
+ read_pointer(&ptr,
(const u8 *)(fde + 1) + *fde,
ptrType & DW_EH_PE_indirect
? ptrType
: ptrType & (DW_EH_PE_FORM|DW_EH_PE_signed));
if (UNW_PC(frame) >= startLoc && UNW_PC(frame) < endLoc)
break;
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;
if ((state.version = *ptr) != 1)
cie = NULL; /* unsupported version */
else if (*++ptr) {
/* check if augmentation size is first (and thus present) */
if (*ptr == 'z') {
/* check for ignorable (or already handled)
* nul-terminated augmentation string */
while (++ptr < end && *ptr)
if (strchr("LPR", *ptr) == NULL)
break;
}
if (ptr >= end || *ptr)
cie = NULL;
}
++ptr;
}
if (cie != NULL) {
/* get code aligment factor */
state.codeAlign = get_uleb128(&ptr, end);
/* get data aligment factor */
state.dataAlign = get_sleb128(&ptr, end);
if (state.codeAlign == 0 || state.dataAlign == 0 || ptr >= end)
cie = NULL;
else {
retAddrReg = state.version <= 1 ? *ptr++ : get_uleb128(&ptr, end);
/* skip augmentation */
if (((const char *)(cie + 2))[1] == 'z')
ptr += get_uleb128(&ptr, end);
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;
#endif
#ifdef CONFIG_FRAME_POINTER
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 (!__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));
/* process instructions */
if (!processCFI(ptr, end, UNW_PC(frame), 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;
/* update frame */
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
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) {
#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:
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:
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: {
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)
return -EIO;
switch(reg_info[i].width) {
#define CASE(n) case sizeof(u##n): \
__get_user(FRAME_REG(i, u##n), (u##n *)addr); \
break
CASES;
#undef CASE
default:
return -EIO;
}
}
break;
}
}
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;
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;
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;
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);
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