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linux/arch/ia64/kernel/unwind.c
Kirill Korotaev 690def2141 [IA64] unwind did not work for processes born with CLONE_STOPPED 
Minor problem for mainstream. Big problem for checkpoint/restore,
because all the stopped/traced processes are born in this state,
hence they cannot be checkpointed again due to failing unwind.

The problem was identified as assumption in kernel unwind library
that top level frame is different of syscall frame. It is the case
unless process was born with CLONE_STOPPED.

Author: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-Off-By: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-Off-By: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2007-05-08 14:51:42 -07:00

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/*
* Copyright (C) 1999-2004 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
* Copyright (C) 2003 Fenghua Yu <fenghua.yu@intel.com>
* - Change pt_regs_off() to make it less dependant on pt_regs structure.
*/
/*
* This file implements call frame unwind support for the Linux
* kernel. Parsing and processing the unwind information is
* time-consuming, so this implementation translates the unwind
* descriptors into unwind scripts. These scripts are very simple
* (basically a sequence of assignments) and efficient to execute.
* They are cached for later re-use. Each script is specific for a
* given instruction pointer address and the set of predicate values
* that the script depends on (most unwind descriptors are
* unconditional and scripts often do not depend on predicates at
* all). This code is based on the unwind conventions described in
* the "IA-64 Software Conventions and Runtime Architecture" manual.
*
* SMP conventions:
* o updates to the global unwind data (in structure "unw") are serialized
* by the unw.lock spinlock
* o each unwind script has its own read-write lock; a thread must acquire
* a read lock before executing a script and must acquire a write lock
* before modifying a script
* o if both the unw.lock spinlock and a script's read-write lock must be
* acquired, then the read-write lock must be acquired first.
*/
#include <linux/module.h>
#include <linux/bootmem.h>
#include <linux/elf.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <asm/unwind.h>
#include <asm/delay.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/ptrace_offsets.h>
#include <asm/rse.h>
#include <asm/sections.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include "entry.h"
#include "unwind_i.h"
#define UNW_LOG_CACHE_SIZE 7 /* each unw_script is ~256 bytes in size */
#define UNW_CACHE_SIZE (1 << UNW_LOG_CACHE_SIZE)
#define UNW_LOG_HASH_SIZE (UNW_LOG_CACHE_SIZE + 1)
#define UNW_HASH_SIZE (1 << UNW_LOG_HASH_SIZE)
#define UNW_STATS 0 /* WARNING: this disabled interrupts for long time-spans!! */
#ifdef UNW_DEBUG
static unsigned int unw_debug_level = UNW_DEBUG;
# define UNW_DEBUG_ON(n) unw_debug_level >= n
/* Do not code a printk level, not all debug lines end in newline */
# define UNW_DPRINT(n, ...) if (UNW_DEBUG_ON(n)) printk(__VA_ARGS__)
# undef inline
# define inline
#else /* !UNW_DEBUG */
# define UNW_DEBUG_ON(n) 0
# define UNW_DPRINT(n, ...)
#endif /* UNW_DEBUG */
#if UNW_STATS
# define STAT(x...) x
#else
# define STAT(x...)
#endif
#define alloc_reg_state() kmalloc(sizeof(struct unw_reg_state), GFP_ATOMIC)
#define free_reg_state(usr) kfree(usr)
#define alloc_labeled_state() kmalloc(sizeof(struct unw_labeled_state), GFP_ATOMIC)
#define free_labeled_state(usr) kfree(usr)
typedef unsigned long unw_word;
typedef unsigned char unw_hash_index_t;
static struct {
spinlock_t lock; /* spinlock for unwind data */
/* list of unwind tables (one per load-module) */
struct unw_table *tables;
unsigned long r0; /* constant 0 for r0 */
/* table of registers that prologues can save (and order in which they're saved): */
const unsigned char save_order[8];
/* maps a preserved register index (preg_index) to corresponding switch_stack offset: */
unsigned short sw_off[sizeof(struct unw_frame_info) / 8];
unsigned short lru_head; /* index of lead-recently used script */
unsigned short lru_tail; /* index of most-recently used script */
/* index into unw_frame_info for preserved register i */
unsigned short preg_index[UNW_NUM_REGS];
short pt_regs_offsets[32];
/* unwind table for the kernel: */
struct unw_table kernel_table;
/* unwind table describing the gate page (kernel code that is mapped into user space): */
size_t gate_table_size;
unsigned long *gate_table;
/* hash table that maps instruction pointer to script index: */
unsigned short hash[UNW_HASH_SIZE];
/* script cache: */
struct unw_script cache[UNW_CACHE_SIZE];
# ifdef UNW_DEBUG
const char *preg_name[UNW_NUM_REGS];
# endif
# if UNW_STATS
struct {
struct {
int lookups;
int hinted_hits;
int normal_hits;
int collision_chain_traversals;
} cache;
struct {
unsigned long build_time;
unsigned long run_time;
unsigned long parse_time;
int builds;
int news;
int collisions;
int runs;
} script;
struct {
unsigned long init_time;
unsigned long unwind_time;
int inits;
int unwinds;
} api;
} stat;
# endif
} unw = {
.tables = &unw.kernel_table,
.lock = __SPIN_LOCK_UNLOCKED(unw.lock),
.save_order = {
UNW_REG_RP, UNW_REG_PFS, UNW_REG_PSP, UNW_REG_PR,
UNW_REG_UNAT, UNW_REG_LC, UNW_REG_FPSR, UNW_REG_PRI_UNAT_GR
},
.preg_index = {
offsetof(struct unw_frame_info, pri_unat_loc)/8, /* PRI_UNAT_GR */
offsetof(struct unw_frame_info, pri_unat_loc)/8, /* PRI_UNAT_MEM */
offsetof(struct unw_frame_info, bsp_loc)/8,
offsetof(struct unw_frame_info, bspstore_loc)/8,
offsetof(struct unw_frame_info, pfs_loc)/8,
offsetof(struct unw_frame_info, rnat_loc)/8,
offsetof(struct unw_frame_info, psp)/8,
offsetof(struct unw_frame_info, rp_loc)/8,
offsetof(struct unw_frame_info, r4)/8,
offsetof(struct unw_frame_info, r5)/8,
offsetof(struct unw_frame_info, r6)/8,
offsetof(struct unw_frame_info, r7)/8,
offsetof(struct unw_frame_info, unat_loc)/8,
offsetof(struct unw_frame_info, pr_loc)/8,
offsetof(struct unw_frame_info, lc_loc)/8,
offsetof(struct unw_frame_info, fpsr_loc)/8,
offsetof(struct unw_frame_info, b1_loc)/8,
offsetof(struct unw_frame_info, b2_loc)/8,
offsetof(struct unw_frame_info, b3_loc)/8,
offsetof(struct unw_frame_info, b4_loc)/8,
offsetof(struct unw_frame_info, b5_loc)/8,
offsetof(struct unw_frame_info, f2_loc)/8,
offsetof(struct unw_frame_info, f3_loc)/8,
offsetof(struct unw_frame_info, f4_loc)/8,
offsetof(struct unw_frame_info, f5_loc)/8,
offsetof(struct unw_frame_info, fr_loc[16 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[17 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[18 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[19 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[20 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[21 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[22 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[23 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[24 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[25 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[26 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[27 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[28 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[29 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[30 - 16])/8,
offsetof(struct unw_frame_info, fr_loc[31 - 16])/8,
},
.pt_regs_offsets = {
[0] = -1,
offsetof(struct pt_regs, r1),
offsetof(struct pt_regs, r2),
offsetof(struct pt_regs, r3),
[4] = -1, [5] = -1, [6] = -1, [7] = -1,
offsetof(struct pt_regs, r8),
offsetof(struct pt_regs, r9),
offsetof(struct pt_regs, r10),
offsetof(struct pt_regs, r11),
offsetof(struct pt_regs, r12),
offsetof(struct pt_regs, r13),
offsetof(struct pt_regs, r14),
offsetof(struct pt_regs, r15),
offsetof(struct pt_regs, r16),
offsetof(struct pt_regs, r17),
offsetof(struct pt_regs, r18),
offsetof(struct pt_regs, r19),
offsetof(struct pt_regs, r20),
offsetof(struct pt_regs, r21),
offsetof(struct pt_regs, r22),
offsetof(struct pt_regs, r23),
offsetof(struct pt_regs, r24),
offsetof(struct pt_regs, r25),
offsetof(struct pt_regs, r26),
offsetof(struct pt_regs, r27),
offsetof(struct pt_regs, r28),
offsetof(struct pt_regs, r29),
offsetof(struct pt_regs, r30),
offsetof(struct pt_regs, r31),
},
.hash = { [0 ... UNW_HASH_SIZE - 1] = -1 },
#ifdef UNW_DEBUG
.preg_name = {
"pri_unat_gr", "pri_unat_mem", "bsp", "bspstore", "ar.pfs", "ar.rnat", "psp", "rp",
"r4", "r5", "r6", "r7",
"ar.unat", "pr", "ar.lc", "ar.fpsr",
"b1", "b2", "b3", "b4", "b5",
"f2", "f3", "f4", "f5",
"f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",
"f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31"
}
#endif
};
static inline int
read_only (void *addr)
{
return (unsigned long) ((char *) addr - (char *) &unw.r0) < sizeof(unw.r0);
}
/*
* Returns offset of rREG in struct pt_regs.
*/
static inline unsigned long
pt_regs_off (unsigned long reg)
{
short off = -1;
if (reg < ARRAY_SIZE(unw.pt_regs_offsets))
off = unw.pt_regs_offsets[reg];
if (off < 0) {
UNW_DPRINT(0, "unwind.%s: bad scratch reg r%lu\n", __FUNCTION__, reg);
off = 0;
}
return (unsigned long) off;
}
static inline struct pt_regs *
get_scratch_regs (struct unw_frame_info *info)
{
if (!info->pt) {
/* This should not happen with valid unwind info. */
UNW_DPRINT(0, "unwind.%s: bad unwind info: resetting info->pt\n", __FUNCTION__);
if (info->flags & UNW_FLAG_INTERRUPT_FRAME)
info->pt = (unsigned long) ((struct pt_regs *) info->psp - 1);
else
info->pt = info->sp - 16;
}
UNW_DPRINT(3, "unwind.%s: sp 0x%lx pt 0x%lx\n", __FUNCTION__, info->sp, info->pt);
return (struct pt_regs *) info->pt;
}
/* Unwind accessors. */
int
unw_access_gr (struct unw_frame_info *info, int regnum, unsigned long *val, char *nat, int write)
{
unsigned long *addr, *nat_addr, nat_mask = 0, dummy_nat;
struct unw_ireg *ireg;
struct pt_regs *pt;
if ((unsigned) regnum - 1 >= 127) {
if (regnum == 0 && !write) {
*val = 0; /* read r0 always returns 0 */
*nat = 0;
return 0;
}
UNW_DPRINT(0, "unwind.%s: trying to access non-existent r%u\n",
__FUNCTION__, regnum);
return -1;
}
if (regnum < 32) {
if (regnum >= 4 && regnum <= 7) {
/* access a preserved register */
ireg = &info->r4 + (regnum - 4);
addr = ireg->loc;
if (addr) {
nat_addr = addr + ireg->nat.off;
switch (ireg->nat.type) {
case UNW_NAT_VAL:
/* simulate getf.sig/setf.sig */
if (write) {
if (*nat) {
/* write NaTVal and be done with it */
addr[0] = 0;
addr[1] = 0x1fffe;
return 0;
}
addr[1] = 0x1003e;
} else {
if (addr[0] == 0 && addr[1] == 0x1ffe) {
/* return NaT and be done with it */
*val = 0;
*nat = 1;
return 0;
}
}
/* fall through */
case UNW_NAT_NONE:
dummy_nat = 0;
nat_addr = &dummy_nat;
break;
case UNW_NAT_MEMSTK:
nat_mask = (1UL << ((long) addr & 0x1f8)/8);
break;
case UNW_NAT_REGSTK:
nat_addr = ia64_rse_rnat_addr(addr);
if ((unsigned long) addr < info->regstk.limit
|| (unsigned long) addr >= info->regstk.top)
{
UNW_DPRINT(0, "unwind.%s: %p outside of regstk "
"[0x%lx-0x%lx)\n",
__FUNCTION__, (void *) addr,
info->regstk.limit,
info->regstk.top);
return -1;
}
if ((unsigned long) nat_addr >= info->regstk.top)
nat_addr = &info->sw->ar_rnat;
nat_mask = (1UL << ia64_rse_slot_num(addr));
break;
}
} else {
addr = &info->sw->r4 + (regnum - 4);
nat_addr = &info->sw->ar_unat;
nat_mask = (1UL << ((long) addr & 0x1f8)/8);
}
} else {
/* access a scratch register */
pt = get_scratch_regs(info);
addr = (unsigned long *) ((unsigned long)pt + pt_regs_off(regnum));
if (info->pri_unat_loc)
nat_addr = info->pri_unat_loc;
else
nat_addr = &info->sw->caller_unat;
nat_mask = (1UL << ((long) addr & 0x1f8)/8);
}
} else {
/* access a stacked register */
addr = ia64_rse_skip_regs((unsigned long *) info->bsp, regnum - 32);
nat_addr = ia64_rse_rnat_addr(addr);
if ((unsigned long) addr < info->regstk.limit
|| (unsigned long) addr >= info->regstk.top)
{
UNW_DPRINT(0, "unwind.%s: ignoring attempt to access register outside "
"of rbs\n", __FUNCTION__);
return -1;
}
if ((unsigned long) nat_addr >= info->regstk.top)
nat_addr = &info->sw->ar_rnat;
nat_mask = (1UL << ia64_rse_slot_num(addr));
}
if (write) {
if (read_only(addr)) {
UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n",
__FUNCTION__);
} else {
*addr = *val;
if (*nat)
*nat_addr |= nat_mask;
else
*nat_addr &= ~nat_mask;
}
} else {
if ((*nat_addr & nat_mask) == 0) {
*val = *addr;
*nat = 0;
} else {
*val = 0; /* if register is a NaT, *addr may contain kernel data! */
*nat = 1;
}
}
return 0;
}
EXPORT_SYMBOL(unw_access_gr);
int
unw_access_br (struct unw_frame_info *info, int regnum, unsigned long *val, int write)
{
unsigned long *addr;
struct pt_regs *pt;
switch (regnum) {
/* scratch: */
case 0: pt = get_scratch_regs(info); addr = &pt->b0; break;
case 6: pt = get_scratch_regs(info); addr = &pt->b6; break;
case 7: pt = get_scratch_regs(info); addr = &pt->b7; break;
/* preserved: */
case 1: case 2: case 3: case 4: case 5:
addr = *(&info->b1_loc + (regnum - 1));
if (!addr)
addr = &info->sw->b1 + (regnum - 1);
break;
default:
UNW_DPRINT(0, "unwind.%s: trying to access non-existent b%u\n",
__FUNCTION__, regnum);
return -1;
}
if (write)
if (read_only(addr)) {
UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n",
__FUNCTION__);
} else
*addr = *val;
else
*val = *addr;
return 0;
}
EXPORT_SYMBOL(unw_access_br);
int
unw_access_fr (struct unw_frame_info *info, int regnum, struct ia64_fpreg *val, int write)
{
struct ia64_fpreg *addr = NULL;
struct pt_regs *pt;
if ((unsigned) (regnum - 2) >= 126) {
UNW_DPRINT(0, "unwind.%s: trying to access non-existent f%u\n",
__FUNCTION__, regnum);
return -1;
}
if (regnum <= 5) {
addr = *(&info->f2_loc + (regnum - 2));
if (!addr)
addr = &info->sw->f2 + (regnum - 2);
} else if (regnum <= 15) {
if (regnum <= 11) {
pt = get_scratch_regs(info);
addr = &pt->f6 + (regnum - 6);
}
else
addr = &info->sw->f12 + (regnum - 12);
} else if (regnum <= 31) {
addr = info->fr_loc[regnum - 16];
if (!addr)
addr = &info->sw->f16 + (regnum - 16);
} else {
struct task_struct *t = info->task;
if (write)
ia64_sync_fph(t);
else
ia64_flush_fph(t);
addr = t->thread.fph + (regnum - 32);
}
if (write)
if (read_only(addr)) {
UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n",
__FUNCTION__);
} else
*addr = *val;
else
*val = *addr;
return 0;
}
EXPORT_SYMBOL(unw_access_fr);
int
unw_access_ar (struct unw_frame_info *info, int regnum, unsigned long *val, int write)
{
unsigned long *addr;
struct pt_regs *pt;
switch (regnum) {
case UNW_AR_BSP:
addr = info->bsp_loc;
if (!addr)
addr = &info->sw->ar_bspstore;
break;
case UNW_AR_BSPSTORE:
addr = info->bspstore_loc;
if (!addr)
addr = &info->sw->ar_bspstore;
break;
case UNW_AR_PFS:
addr = info->pfs_loc;
if (!addr)
addr = &info->sw->ar_pfs;
break;
case UNW_AR_RNAT:
addr = info->rnat_loc;
if (!addr)
addr = &info->sw->ar_rnat;
break;
case UNW_AR_UNAT:
addr = info->unat_loc;
if (!addr)
addr = &info->sw->caller_unat;
break;
case UNW_AR_LC:
addr = info->lc_loc;
if (!addr)
addr = &info->sw->ar_lc;
break;
case UNW_AR_EC:
if (!info->cfm_loc)
return -1;
if (write)
*info->cfm_loc =
(*info->cfm_loc & ~(0x3fUL << 52)) | ((*val & 0x3f) << 52);
else
*val = (*info->cfm_loc >> 52) & 0x3f;
return 0;
case UNW_AR_FPSR:
addr = info->fpsr_loc;
if (!addr)
addr = &info->sw->ar_fpsr;
break;
case UNW_AR_RSC:
pt = get_scratch_regs(info);
addr = &pt->ar_rsc;
break;
case UNW_AR_CCV:
pt = get_scratch_regs(info);
addr = &pt->ar_ccv;
break;
case UNW_AR_CSD:
pt = get_scratch_regs(info);
addr = &pt->ar_csd;
break;
case UNW_AR_SSD:
pt = get_scratch_regs(info);
addr = &pt->ar_ssd;
break;
default:
UNW_DPRINT(0, "unwind.%s: trying to access non-existent ar%u\n",
__FUNCTION__, regnum);
return -1;
}
if (write) {
if (read_only(addr)) {
UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n",
__FUNCTION__);
} else
*addr = *val;
} else
*val = *addr;
return 0;
}
EXPORT_SYMBOL(unw_access_ar);
int
unw_access_pr (struct unw_frame_info *info, unsigned long *val, int write)
{
unsigned long *addr;
addr = info->pr_loc;
if (!addr)
addr = &info->sw->pr;
if (write) {
if (read_only(addr)) {
UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n",
__FUNCTION__);
} else
*addr = *val;
} else
*val = *addr;
return 0;
}
EXPORT_SYMBOL(unw_access_pr);
/* Routines to manipulate the state stack. */
static inline void
push (struct unw_state_record *sr)
{
struct unw_reg_state *rs;
rs = alloc_reg_state();
if (!rs) {
printk(KERN_ERR "unwind: cannot stack reg state!\n");
return;
}
memcpy(rs, &sr->curr, sizeof(*rs));
sr->curr.next = rs;
}
static void
pop (struct unw_state_record *sr)
{
struct unw_reg_state *rs = sr->curr.next;
if (!rs) {
printk(KERN_ERR "unwind: stack underflow!\n");
return;
}
memcpy(&sr->curr, rs, sizeof(*rs));
free_reg_state(rs);
}
/* Make a copy of the state stack. Non-recursive to avoid stack overflows. */
static struct unw_reg_state *
dup_state_stack (struct unw_reg_state *rs)
{
struct unw_reg_state *copy, *prev = NULL, *first = NULL;
while (rs) {
copy = alloc_reg_state();
if (!copy) {
printk(KERN_ERR "unwind.dup_state_stack: out of memory\n");
return NULL;
}
memcpy(copy, rs, sizeof(*copy));
if (first)
prev->next = copy;
else
first = copy;
rs = rs->next;
prev = copy;
}
return first;
}
/* Free all stacked register states (but not RS itself). */
static void
free_state_stack (struct unw_reg_state *rs)
{
struct unw_reg_state *p, *next;
for (p = rs->next; p != NULL; p = next) {
next = p->next;
free_reg_state(p);
}
rs->next = NULL;
}
/* Unwind decoder routines */
static enum unw_register_index __attribute_const__
decode_abreg (unsigned char abreg, int memory)
{
switch (abreg) {
case 0x04 ... 0x07: return UNW_REG_R4 + (abreg - 0x04);
case 0x22 ... 0x25: return UNW_REG_F2 + (abreg - 0x22);
case 0x30 ... 0x3f: return UNW_REG_F16 + (abreg - 0x30);
case 0x41 ... 0x45: return UNW_REG_B1 + (abreg - 0x41);
case 0x60: return UNW_REG_PR;
case 0x61: return UNW_REG_PSP;
case 0x62: return memory ? UNW_REG_PRI_UNAT_MEM : UNW_REG_PRI_UNAT_GR;
case 0x63: return UNW_REG_RP;
case 0x64: return UNW_REG_BSP;
case 0x65: return UNW_REG_BSPSTORE;
case 0x66: return UNW_REG_RNAT;
case 0x67: return UNW_REG_UNAT;
case 0x68: return UNW_REG_FPSR;
case 0x69: return UNW_REG_PFS;
case 0x6a: return UNW_REG_LC;
default:
break;
}
UNW_DPRINT(0, "unwind.%s: bad abreg=0x%x\n", __FUNCTION__, abreg);
return UNW_REG_LC;
}
static void
set_reg (struct unw_reg_info *reg, enum unw_where where, int when, unsigned long val)
{
reg->val = val;
reg->where = where;
if (reg->when == UNW_WHEN_NEVER)
reg->when = when;
}
static void
alloc_spill_area (unsigned long *offp, unsigned long regsize,
struct unw_reg_info *lo, struct unw_reg_info *hi)
{
struct unw_reg_info *reg;
for (reg = hi; reg >= lo; --reg) {
if (reg->where == UNW_WHERE_SPILL_HOME) {
reg->where = UNW_WHERE_PSPREL;
*offp -= regsize;
reg->val = *offp;
}
}
}
static inline void
spill_next_when (struct unw_reg_info **regp, struct unw_reg_info *lim, unw_word t)
{
struct unw_reg_info *reg;
for (reg = *regp; reg <= lim; ++reg) {
if (reg->where == UNW_WHERE_SPILL_HOME) {
reg->when = t;
*regp = reg + 1;
return;
}
}
UNW_DPRINT(0, "unwind.%s: excess spill!\n", __FUNCTION__);
}
static inline void
finish_prologue (struct unw_state_record *sr)
{
struct unw_reg_info *reg;
unsigned long off;
int i;
/*
* First, resolve implicit register save locations (see Section "11.4.2.3 Rules
* for Using Unwind Descriptors", rule 3):
*/
for (i = 0; i < (int) ARRAY_SIZE(unw.save_order); ++i) {
reg = sr->curr.reg + unw.save_order[i];
if (reg->where == UNW_WHERE_GR_SAVE) {
reg->where = UNW_WHERE_GR;
reg->val = sr->gr_save_loc++;
}
}
/*
* Next, compute when the fp, general, and branch registers get
* saved. This must come before alloc_spill_area() because
* we need to know which registers are spilled to their home
* locations.
*/
if (sr->imask) {
unsigned char kind, mask = 0, *cp = sr->imask;
int t;
static const unsigned char limit[3] = {
UNW_REG_F31, UNW_REG_R7, UNW_REG_B5
};
struct unw_reg_info *(regs[3]);
regs[0] = sr->curr.reg + UNW_REG_F2;
regs[1] = sr->curr.reg + UNW_REG_R4;
regs[2] = sr->curr.reg + UNW_REG_B1;
for (t = 0; t < sr->region_len; ++t) {
if ((t & 3) == 0)
mask = *cp++;
kind = (mask >> 2*(3-(t & 3))) & 3;
if (kind > 0)
spill_next_when(&regs[kind - 1], sr->curr.reg + limit[kind - 1],
sr->region_start + t);
}
}
/*
* Next, lay out the memory stack spill area:
*/
if (sr->any_spills) {
off = sr->spill_offset;
alloc_spill_area(&off, 16, sr->curr.reg + UNW_REG_F2, sr->curr.reg + UNW_REG_F31);
alloc_spill_area(&off, 8, sr->curr.reg + UNW_REG_B1, sr->curr.reg + UNW_REG_B5);
alloc_spill_area(&off, 8, sr->curr.reg + UNW_REG_R4, sr->curr.reg + UNW_REG_R7);
}
}
/*
* Region header descriptors.
*/
static void
desc_prologue (int body, unw_word rlen, unsigned char mask, unsigned char grsave,
struct unw_state_record *sr)
{
int i, region_start;
if (!(sr->in_body || sr->first_region))
finish_prologue(sr);
sr->first_region = 0;
/* check if we're done: */
if (sr->when_target < sr->region_start + sr->region_len) {
sr->done = 1;
return;
}
region_start = sr->region_start + sr->region_len;
for (i = 0; i < sr->epilogue_count; ++i)
pop(sr);
sr->epilogue_count = 0;
sr->epilogue_start = UNW_WHEN_NEVER;
sr->region_start = region_start;
sr->region_len = rlen;
sr->in_body = body;
if (!body) {
push(sr);
for (i = 0; i < 4; ++i) {
if (mask & 0x8)
set_reg(sr->curr.reg + unw.save_order[i], UNW_WHERE_GR,
sr->region_start + sr->region_len - 1, grsave++);
mask <<= 1;
}
sr->gr_save_loc = grsave;
sr->any_spills = 0;
sr->imask = NULL;
sr->spill_offset = 0x10; /* default to psp+16 */
}
}
/*
* Prologue descriptors.
*/
static inline void
desc_abi (unsigned char abi, unsigned char context, struct unw_state_record *sr)
{
if (abi == 3 && context == 'i') {
sr->flags |= UNW_FLAG_INTERRUPT_FRAME;
UNW_DPRINT(3, "unwind.%s: interrupt frame\n", __FUNCTION__);
}
else
UNW_DPRINT(0, "unwind%s: ignoring unwabi(abi=0x%x,context=0x%x)\n",
__FUNCTION__, abi, context);
}
static inline void
desc_br_gr (unsigned char brmask, unsigned char gr, struct unw_state_record *sr)
{
int i;
for (i = 0; i < 5; ++i) {
if (brmask & 1)
set_reg(sr->curr.reg + UNW_REG_B1 + i, UNW_WHERE_GR,
sr->region_start + sr->region_len - 1, gr++);
brmask >>= 1;
}
}
static inline void
desc_br_mem (unsigned char brmask, struct unw_state_record *sr)
{
int i;
for (i = 0; i < 5; ++i) {
if (brmask & 1) {
set_reg(sr->curr.reg + UNW_REG_B1 + i, UNW_WHERE_SPILL_HOME,
sr->region_start + sr->region_len - 1, 0);
sr->any_spills = 1;
}
brmask >>= 1;
}
}
static inline void
desc_frgr_mem (unsigned char grmask, unw_word frmask, struct unw_state_record *sr)
{
int i;
for (i = 0; i < 4; ++i) {
if ((grmask & 1) != 0) {
set_reg(sr->curr.reg + UNW_REG_R4 + i, UNW_WHERE_SPILL_HOME,
sr->region_start + sr->region_len - 1, 0);
sr->any_spills = 1;
}
grmask >>= 1;
}
for (i = 0; i < 20; ++i) {
if ((frmask & 1) != 0) {
int base = (i < 4) ? UNW_REG_F2 : UNW_REG_F16 - 4;
set_reg(sr->curr.reg + base + i, UNW_WHERE_SPILL_HOME,
sr->region_start + sr->region_len - 1, 0);
sr->any_spills = 1;
}
frmask >>= 1;
}
}
static inline void
desc_fr_mem (unsigned char frmask, struct unw_state_record *sr)
{
int i;
for (i = 0; i < 4; ++i) {
if ((frmask & 1) != 0) {
set_reg(sr->curr.reg + UNW_REG_F2 + i, UNW_WHERE_SPILL_HOME,
sr->region_start + sr->region_len - 1, 0);
sr->any_spills = 1;
}
frmask >>= 1;
}
}
static inline void
desc_gr_gr (unsigned char grmask, unsigned char gr, struct unw_state_record *sr)
{
int i;
for (i = 0; i < 4; ++i) {
if ((grmask & 1) != 0)
set_reg(sr->curr.reg + UNW_REG_R4 + i, UNW_WHERE_GR,
sr->region_start + sr->region_len - 1, gr++);
grmask >>= 1;
}
}
static inline void
desc_gr_mem (unsigned char grmask, struct unw_state_record *sr)
{
int i;
for (i = 0; i < 4; ++i) {
if ((grmask & 1) != 0) {
set_reg(sr->curr.reg + UNW_REG_R4 + i, UNW_WHERE_SPILL_HOME,
sr->region_start + sr->region_len - 1, 0);
sr->any_spills = 1;
}
grmask >>= 1;
}
}
static inline void
desc_mem_stack_f (unw_word t, unw_word size, struct unw_state_record *sr)
{
set_reg(sr->curr.reg + UNW_REG_PSP, UNW_WHERE_NONE,
sr->region_start + min_t(int, t, sr->region_len - 1), 16*size);
}
static inline void
desc_mem_stack_v (unw_word t, struct unw_state_record *sr)
{
sr->curr.reg[UNW_REG_PSP].when = sr->region_start + min_t(int, t, sr->region_len - 1);
}
static inline void
desc_reg_gr (unsigned char reg, unsigned char dst, struct unw_state_record *sr)
{
set_reg(sr->curr.reg + reg, UNW_WHERE_GR, sr->region_start + sr->region_len - 1, dst);
}
static inline void
desc_reg_psprel (unsigned char reg, unw_word pspoff, struct unw_state_record *sr)
{
set_reg(sr->curr.reg + reg, UNW_WHERE_PSPREL, sr->region_start + sr->region_len - 1,
0x10 - 4*pspoff);
}
static inline void
desc_reg_sprel (unsigned char reg, unw_word spoff, struct unw_state_record *sr)
{
set_reg(sr->curr.reg + reg, UNW_WHERE_SPREL, sr->region_start + sr->region_len - 1,
4*spoff);
}
static inline void
desc_rp_br (unsigned char dst, struct unw_state_record *sr)
{
sr->return_link_reg = dst;
}
static inline void
desc_reg_when (unsigned char regnum, unw_word t, struct unw_state_record *sr)
{
struct unw_reg_info *reg = sr->curr.reg + regnum;
if (reg->where == UNW_WHERE_NONE)
reg->where = UNW_WHERE_GR_SAVE;
reg->when = sr->region_start + min_t(int, t, sr->region_len - 1);
}
static inline void
desc_spill_base (unw_word pspoff, struct unw_state_record *sr)
{
sr->spill_offset = 0x10 - 4*pspoff;
}
static inline unsigned char *
desc_spill_mask (unsigned char *imaskp, struct unw_state_record *sr)
{
sr->imask = imaskp;
return imaskp + (2*sr->region_len + 7)/8;
}
/*
* Body descriptors.
*/
static inline void
desc_epilogue (unw_word t, unw_word ecount, struct unw_state_record *sr)
{
sr->epilogue_start = sr->region_start + sr->region_len - 1 - t;
sr->epilogue_count = ecount + 1;
}
static inline void
desc_copy_state (unw_word label, struct unw_state_record *sr)
{
struct unw_labeled_state *ls;
for (ls = sr->labeled_states; ls; ls = ls->next) {
if (ls->label == label) {
free_state_stack(&sr->curr);
memcpy(&sr->curr, &ls->saved_state, sizeof(sr->curr));
sr->curr.next = dup_state_stack(ls->saved_state.next);
return;
}
}
printk(KERN_ERR "unwind: failed to find state labeled 0x%lx\n", label);
}
static inline void
desc_label_state (unw_word label, struct unw_state_record *sr)
{
struct unw_labeled_state *ls;
ls = alloc_labeled_state();
if (!ls) {
printk(KERN_ERR "unwind.desc_label_state(): out of memory\n");
return;
}
ls->label = label;
memcpy(&ls->saved_state, &sr->curr, sizeof(ls->saved_state));
ls->saved_state.next = dup_state_stack(sr->curr.next);
/* insert into list of labeled states: */
ls->next = sr->labeled_states;
sr->labeled_states = ls;
}
/*
* General descriptors.
*/
static inline int
desc_is_active (unsigned char qp, unw_word t, struct unw_state_record *sr)
{
if (sr->when_target <= sr->region_start + min_t(int, t, sr->region_len - 1))
return 0;
if (qp > 0) {
if ((sr->pr_val & (1UL << qp)) == 0)
return 0;
sr->pr_mask |= (1UL << qp);
}
return 1;
}
static inline void
desc_restore_p (unsigned char qp, unw_word t, unsigned char abreg, struct unw_state_record *sr)
{
struct unw_reg_info *r;
if (!desc_is_active(qp, t, sr))
return;
r = sr->curr.reg + decode_abreg(abreg, 0);
r->where = UNW_WHERE_NONE;
r->when = UNW_WHEN_NEVER;
r->val = 0;
}
static inline void
desc_spill_reg_p (unsigned char qp, unw_word t, unsigned char abreg, unsigned char x,
unsigned char ytreg, struct unw_state_record *sr)
{
enum unw_where where = UNW_WHERE_GR;
struct unw_reg_info *r;
if (!desc_is_active(qp, t, sr))
return;
if (x)
where = UNW_WHERE_BR;
else if (ytreg & 0x80)
where = UNW_WHERE_FR;
r = sr->curr.reg + decode_abreg(abreg, 0);
r->where = where;
r->when = sr->region_start + min_t(int, t, sr->region_len - 1);
r->val = (ytreg & 0x7f);
}
static inline void
desc_spill_psprel_p (unsigned char qp, unw_word t, unsigned char abreg, unw_word pspoff,
struct unw_state_record *sr)
{
struct unw_reg_info *r;
if (!desc_is_active(qp, t, sr))
return;
r = sr->curr.reg + decode_abreg(abreg, 1);
r->where = UNW_WHERE_PSPREL;
r->when = sr->region_start + min_t(int, t, sr->region_len - 1);
r->val = 0x10 - 4*pspoff;
}
static inline void
desc_spill_sprel_p (unsigned char qp, unw_word t, unsigned char abreg, unw_word spoff,
struct unw_state_record *sr)
{
struct unw_reg_info *r;
if (!desc_is_active(qp, t, sr))
return;
r = sr->curr.reg + decode_abreg(abreg, 1);
r->where = UNW_WHERE_SPREL;
r->when = sr->region_start + min_t(int, t, sr->region_len - 1);
r->val = 4*spoff;
}
#define UNW_DEC_BAD_CODE(code) printk(KERN_ERR "unwind: unknown code 0x%02x\n", \
code);
/*
* region headers:
*/
#define UNW_DEC_PROLOGUE_GR(fmt,r,m,gr,arg) desc_prologue(0,r,m,gr,arg)
#define UNW_DEC_PROLOGUE(fmt,b,r,arg) desc_prologue(b,r,0,32,arg)
/*
* prologue descriptors:
*/
#define UNW_DEC_ABI(fmt,a,c,arg) desc_abi(a,c,arg)
#define UNW_DEC_BR_GR(fmt,b,g,arg) desc_br_gr(b,g,arg)
#define UNW_DEC_BR_MEM(fmt,b,arg) desc_br_mem(b,arg)
#define UNW_DEC_FRGR_MEM(fmt,g,f,arg) desc_frgr_mem(g,f,arg)
#define UNW_DEC_FR_MEM(fmt,f,arg) desc_fr_mem(f,arg)
#define UNW_DEC_GR_GR(fmt,m,g,arg) desc_gr_gr(m,g,arg)
#define UNW_DEC_GR_MEM(fmt,m,arg) desc_gr_mem(m,arg)
#define UNW_DEC_MEM_STACK_F(fmt,t,s,arg) desc_mem_stack_f(t,s,arg)
#define UNW_DEC_MEM_STACK_V(fmt,t,arg) desc_mem_stack_v(t,arg)
#define UNW_DEC_REG_GR(fmt,r,d,arg) desc_reg_gr(r,d,arg)
#define UNW_DEC_REG_PSPREL(fmt,r,o,arg) desc_reg_psprel(r,o,arg)
#define UNW_DEC_REG_SPREL(fmt,r,o,arg) desc_reg_sprel(r,o,arg)
#define UNW_DEC_REG_WHEN(fmt,r,t,arg) desc_reg_when(r,t,arg)
#define UNW_DEC_PRIUNAT_WHEN_GR(fmt,t,arg) desc_reg_when(UNW_REG_PRI_UNAT_GR,t,arg)
#define UNW_DEC_PRIUNAT_WHEN_MEM(fmt,t,arg) desc_reg_when(UNW_REG_PRI_UNAT_MEM,t,arg)
#define UNW_DEC_PRIUNAT_GR(fmt,r,arg) desc_reg_gr(UNW_REG_PRI_UNAT_GR,r,arg)
#define UNW_DEC_PRIUNAT_PSPREL(fmt,o,arg) desc_reg_psprel(UNW_REG_PRI_UNAT_MEM,o,arg)
#define UNW_DEC_PRIUNAT_SPREL(fmt,o,arg) desc_reg_sprel(UNW_REG_PRI_UNAT_MEM,o,arg)
#define UNW_DEC_RP_BR(fmt,d,arg) desc_rp_br(d,arg)
#define UNW_DEC_SPILL_BASE(fmt,o,arg) desc_spill_base(o,arg)
#define UNW_DEC_SPILL_MASK(fmt,m,arg) (m = desc_spill_mask(m,arg))
/*
* body descriptors:
*/
#define UNW_DEC_EPILOGUE(fmt,t,c,arg) desc_epilogue(t,c,arg)
#define UNW_DEC_COPY_STATE(fmt,l,arg) desc_copy_state(l,arg)
#define UNW_DEC_LABEL_STATE(fmt,l,arg) desc_label_state(l,arg)
/*
* general unwind descriptors:
*/
#define UNW_DEC_SPILL_REG_P(f,p,t,a,x,y,arg) desc_spill_reg_p(p,t,a,x,y,arg)
#define UNW_DEC_SPILL_REG(f,t,a,x,y,arg) desc_spill_reg_p(0,t,a,x,y,arg)
#define UNW_DEC_SPILL_PSPREL_P(f,p,t,a,o,arg) desc_spill_psprel_p(p,t,a,o,arg)
#define UNW_DEC_SPILL_PSPREL(f,t,a,o,arg) desc_spill_psprel_p(0,t,a,o,arg)
#define UNW_DEC_SPILL_SPREL_P(f,p,t,a,o,arg) desc_spill_sprel_p(p,t,a,o,arg)
#define UNW_DEC_SPILL_SPREL(f,t,a,o,arg) desc_spill_sprel_p(0,t,a,o,arg)
#define UNW_DEC_RESTORE_P(f,p,t,a,arg) desc_restore_p(p,t,a,arg)
#define UNW_DEC_RESTORE(f,t,a,arg) desc_restore_p(0,t,a,arg)
#include "unwind_decoder.c"
/* Unwind scripts. */
static inline unw_hash_index_t
hash (unsigned long ip)
{
# define hashmagic 0x9e3779b97f4a7c16UL /* based on (sqrt(5)/2-1)*2^64 */
return (ip >> 4)*hashmagic >> (64 - UNW_LOG_HASH_SIZE);
#undef hashmagic
}
static inline long
cache_match (struct unw_script *script, unsigned long ip, unsigned long pr)
{
read_lock(&script->lock);
if (ip == script->ip && ((pr ^ script->pr_val) & script->pr_mask) == 0)
/* keep the read lock... */
return 1;
read_unlock(&script->lock);
return 0;
}
static inline struct unw_script *
script_lookup (struct unw_frame_info *info)
{
struct unw_script *script = unw.cache + info->hint;
unsigned short index;
unsigned long ip, pr;
if (UNW_DEBUG_ON(0))
return NULL; /* Always regenerate scripts in debug mode */
STAT(++unw.stat.cache.lookups);
ip = info->ip;
pr = info->pr;
if (cache_match(script, ip, pr)) {
STAT(++unw.stat.cache.hinted_hits);
return script;
}
index = unw.hash[hash(ip)];
if (index >= UNW_CACHE_SIZE)
return NULL;
script = unw.cache + index;
while (1) {
if (cache_match(script, ip, pr)) {
/* update hint; no locking required as single-word writes are atomic */
STAT(++unw.stat.cache.normal_hits);
unw.cache[info->prev_script].hint = script - unw.cache;
return script;
}
if (script->coll_chain >= UNW_HASH_SIZE)
return NULL;
script = unw.cache + script->coll_chain;
STAT(++unw.stat.cache.collision_chain_traversals);
}
}
/*
* On returning, a write lock for the SCRIPT is still being held.
*/
static inline struct unw_script *
script_new (unsigned long ip)
{
struct unw_script *script, *prev, *tmp;
unw_hash_index_t index;
unsigned short head;
STAT(++unw.stat.script.news);
/*
* Can't (easily) use cmpxchg() here because of ABA problem
* that is intrinsic in cmpxchg()...
*/
head = unw.lru_head;
script = unw.cache + head;
unw.lru_head = script->lru_chain;
/*
* We'd deadlock here if we interrupted a thread that is holding a read lock on
* script->lock. Thus, if the write_trylock() fails, we simply bail out. The
* alternative would be to disable interrupts whenever we hold a read-lock, but
* that seems silly.
*/
if (!write_trylock(&script->lock))
return NULL;
/* re-insert script at the tail of the LRU chain: */
unw.cache[unw.lru_tail].lru_chain = head;
unw.lru_tail = head;
/* remove the old script from the hash table (if it's there): */
if (script->ip) {
index = hash(script->ip);
tmp = unw.cache + unw.hash[index];
prev = NULL;
while (1) {
if (tmp == script) {
if (prev)
prev->coll_chain = tmp->coll_chain;
else
unw.hash[index] = tmp->coll_chain;
break;
} else
prev = tmp;
if (tmp->coll_chain >= UNW_CACHE_SIZE)
/* old script wasn't in the hash-table */
break;
tmp = unw.cache + tmp->coll_chain;
}
}
/* enter new script in the hash table */
index = hash(ip);
script->coll_chain = unw.hash[index];
unw.hash[index] = script - unw.cache;
script->ip = ip; /* set new IP while we're holding the locks */
STAT(if (script->coll_chain < UNW_CACHE_SIZE) ++unw.stat.script.collisions);
script->flags = 0;
script->hint = 0;
script->count = 0;
return script;
}
static void
script_finalize (struct unw_script *script, struct unw_state_record *sr)
{
script->pr_mask = sr->pr_mask;
script->pr_val = sr->pr_val;
/*
* We could down-grade our write-lock on script->lock here but
* the rwlock API doesn't offer atomic lock downgrading, so
* we'll just keep the write-lock and release it later when
* we're done using the script.
*/
}
static inline void
script_emit (struct unw_script *script, struct unw_insn insn)
{
if (script->count >= UNW_MAX_SCRIPT_LEN) {
UNW_DPRINT(0, "unwind.%s: script exceeds maximum size of %u instructions!\n",
__FUNCTION__, UNW_MAX_SCRIPT_LEN);
return;
}
script->insn[script->count++] = insn;
}
static inline void
emit_nat_info (struct unw_state_record *sr, int i, struct unw_script *script)
{
struct unw_reg_info *r = sr->curr.reg + i;
enum unw_insn_opcode opc;
struct unw_insn insn;
unsigned long val = 0;
switch (r->where) {
case UNW_WHERE_GR:
if (r->val >= 32) {
/* register got spilled to a stacked register */
opc = UNW_INSN_SETNAT_TYPE;
val = UNW_NAT_REGSTK;
} else
/* register got spilled to a scratch register */
opc = UNW_INSN_SETNAT_MEMSTK;
break;
case UNW_WHERE_FR:
opc = UNW_INSN_SETNAT_TYPE;
val = UNW_NAT_VAL;
break;
case UNW_WHERE_BR:
opc = UNW_INSN_SETNAT_TYPE;
val = UNW_NAT_NONE;
break;
case UNW_WHERE_PSPREL:
case UNW_WHERE_SPREL:
opc = UNW_INSN_SETNAT_MEMSTK;
break;
default:
UNW_DPRINT(0, "unwind.%s: don't know how to emit nat info for where = %u\n",
__FUNCTION__, r->where);
return;
}
insn.opc = opc;
insn.dst = unw.preg_index[i];
insn.val = val;
script_emit(script, insn);
}
static void
compile_reg (struct unw_state_record *sr, int i, struct unw_script *script)
{
struct unw_reg_info *r = sr->curr.reg + i;
enum unw_insn_opcode opc;
unsigned long val, rval;
struct unw_insn insn;
long need_nat_info;
if (r->where == UNW_WHERE_NONE || r->when >= sr->when_target)
return;
opc = UNW_INSN_MOVE;
val = rval = r->val;
need_nat_info = (i >= UNW_REG_R4 && i <= UNW_REG_R7);
switch (r->where) {
case UNW_WHERE_GR:
if (rval >= 32) {
opc = UNW_INSN_MOVE_STACKED;
val = rval - 32;
} else if (rval >= 4 && rval <= 7) {
if (need_nat_info) {
opc = UNW_INSN_MOVE2;
need_nat_info = 0;
}
val = unw.preg_index[UNW_REG_R4 + (rval - 4)];
} else if (rval == 0) {
opc = UNW_INSN_MOVE_CONST;
val = 0;
} else {
/* register got spilled to a scratch register */
opc = UNW_INSN_MOVE_SCRATCH;
val = pt_regs_off(rval);
}
break;
case UNW_WHERE_FR:
if (rval <= 5)
val = unw.preg_index[UNW_REG_F2 + (rval - 2)];
else if (rval >= 16 && rval <= 31)
val = unw.preg_index[UNW_REG_F16 + (rval - 16)];
else {
opc = UNW_INSN_MOVE_SCRATCH;
if (rval <= 11)
val = offsetof(struct pt_regs, f6) + 16*(rval - 6);
else
UNW_DPRINT(0, "unwind.%s: kernel may not touch f%lu\n",
__FUNCTION__, rval);
}
break;
case UNW_WHERE_BR:
if (rval >= 1 && rval <= 5)
val = unw.preg_index[UNW_REG_B1 + (rval - 1)];
else {
opc = UNW_INSN_MOVE_SCRATCH;
if (rval == 0)
val = offsetof(struct pt_regs, b0);
else if (rval == 6)
val = offsetof(struct pt_regs, b6);
else
val = offsetof(struct pt_regs, b7);
}
break;
case UNW_WHERE_SPREL:
opc = UNW_INSN_ADD_SP;
break;
case UNW_WHERE_PSPREL:
opc = UNW_INSN_ADD_PSP;
break;
default:
UNW_DPRINT(0, "unwind%s: register %u has unexpected `where' value of %u\n",
__FUNCTION__, i, r->where);
break;
}
insn.opc = opc;
insn.dst = unw.preg_index[i];
insn.val = val;
script_emit(script, insn);
if (need_nat_info)
emit_nat_info(sr, i, script);
if (i == UNW_REG_PSP) {
/*
* info->psp must contain the _value_ of the previous
* sp, not it's save location. We get this by
* dereferencing the value we just stored in
* info->psp:
*/
insn.opc = UNW_INSN_LOAD;
insn.dst = insn.val = unw.preg_index[UNW_REG_PSP];
script_emit(script, insn);
}
}
static inline const struct unw_table_entry *
lookup (struct unw_table *table, unsigned long rel_ip)
{
const struct unw_table_entry *e = NULL;
unsigned long lo, hi, mid;
/* do a binary search for right entry: */
for (lo = 0, hi = table->length; lo < hi; ) {
mid = (lo + hi) / 2;
e = &table->array[mid];
if (rel_ip < e->start_offset)
hi = mid;
else if (rel_ip >= e->end_offset)
lo = mid + 1;
else
break;
}
if (rel_ip < e->start_offset || rel_ip >= e->end_offset)
return NULL;
return e;
}
/*
* Build an unwind script that unwinds from state OLD_STATE to the
* entrypoint of the function that called OLD_STATE.
*/
static inline struct unw_script *
build_script (struct unw_frame_info *info)
{
const struct unw_table_entry *e = NULL;
struct unw_script *script = NULL;
struct unw_labeled_state *ls, *next;
unsigned long ip = info->ip;
struct unw_state_record sr;
struct unw_table *table;
struct unw_reg_info *r;
struct unw_insn insn;
u8 *dp, *desc_end;
u64 hdr;
int i;
STAT(unsigned long start, parse_start;)
STAT(++unw.stat.script.builds; start = ia64_get_itc());
/* build state record */
memset(&sr, 0, sizeof(sr));
for (r = sr.curr.reg; r < sr.curr.reg + UNW_NUM_REGS; ++r)
r->when = UNW_WHEN_NEVER;
sr.pr_val = info->pr;
UNW_DPRINT(3, "unwind.%s: ip 0x%lx\n", __FUNCTION__, ip);
script = script_new(ip);
if (!script) {
UNW_DPRINT(0, "unwind.%s: failed to create unwind script\n", __FUNCTION__);
STAT(unw.stat.script.build_time += ia64_get_itc() - start);
return NULL;
}
unw.cache[info->prev_script].hint = script - unw.cache;
/* search the kernels and the modules' unwind tables for IP: */
STAT(parse_start = ia64_get_itc());
for (table = unw.tables; table; table = table->next) {
if (ip >= table->start && ip < table->end) {
e = lookup(table, ip - table->segment_base);
break;
}
}
if (!e) {
/* no info, return default unwinder (leaf proc, no mem stack, no saved regs) */
UNW_DPRINT(1, "unwind.%s: no unwind info for ip=0x%lx (prev ip=0x%lx)\n",
__FUNCTION__, ip, unw.cache[info->prev_script].ip);
sr.curr.reg[UNW_REG_RP].where = UNW_WHERE_BR;
sr.curr.reg[UNW_REG_RP].when = -1;
sr.curr.reg[UNW_REG_RP].val = 0;
compile_reg(&sr, UNW_REG_RP, script);
script_finalize(script, &sr);
STAT(unw.stat.script.parse_time += ia64_get_itc() - parse_start);
STAT(unw.stat.script.build_time += ia64_get_itc() - start);
return script;
}
sr.when_target = (3*((ip & ~0xfUL) - (table->segment_base + e->start_offset))/16
+ (ip & 0xfUL));
hdr = *(u64 *) (table->segment_base + e->info_offset);
dp = (u8 *) (table->segment_base + e->info_offset + 8);
desc_end = dp + 8*UNW_LENGTH(hdr);
while (!sr.done && dp < desc_end)
dp = unw_decode(dp, sr.in_body, &sr);
if (sr.when_target > sr.epilogue_start) {
/*
* sp has been restored and all values on the memory stack below
* psp also have been restored.
*/
sr.curr.reg[UNW_REG_PSP].val = 0;
sr.curr.reg[UNW_REG_PSP].where = UNW_WHERE_NONE;
sr.curr.reg[UNW_REG_PSP].when = UNW_WHEN_NEVER;
for (r = sr.curr.reg; r < sr.curr.reg + UNW_NUM_REGS; ++r)
if ((r->where == UNW_WHERE_PSPREL && r->val <= 0x10)
|| r->where == UNW_WHERE_SPREL)
{
r->val = 0;
r->where = UNW_WHERE_NONE;
r->when = UNW_WHEN_NEVER;
}
}
script->flags = sr.flags;
/*
* If RP did't get saved, generate entry for the return link
* register.
*/
if (sr.curr.reg[UNW_REG_RP].when >= sr.when_target) {
sr.curr.reg[UNW_REG_RP].where = UNW_WHERE_BR;
sr.curr.reg[UNW_REG_RP].when = -1;
sr.curr.reg[UNW_REG_RP].val = sr.return_link_reg;
UNW_DPRINT(1, "unwind.%s: using default for rp at ip=0x%lx where=%d val=0x%lx\n",
__FUNCTION__, ip, sr.curr.reg[UNW_REG_RP].where,
sr.curr.reg[UNW_REG_RP].val);
}
#ifdef UNW_DEBUG
UNW_DPRINT(1, "unwind.%s: state record for func 0x%lx, t=%u:\n",
__FUNCTION__, table->segment_base + e->start_offset, sr.when_target);
for (r = sr.curr.reg; r < sr.curr.reg + UNW_NUM_REGS; ++r) {
if (r->where != UNW_WHERE_NONE || r->when != UNW_WHEN_NEVER) {
UNW_DPRINT(1, " %s <- ", unw.preg_name[r - sr.curr.reg]);
switch (r->where) {
case UNW_WHERE_GR: UNW_DPRINT(1, "r%lu", r->val); break;
case UNW_WHERE_FR: UNW_DPRINT(1, "f%lu", r->val); break;
case UNW_WHERE_BR: UNW_DPRINT(1, "b%lu", r->val); break;
case UNW_WHERE_SPREL: UNW_DPRINT(1, "[sp+0x%lx]", r->val); break;
case UNW_WHERE_PSPREL: UNW_DPRINT(1, "[psp+0x%lx]", r->val); break;
case UNW_WHERE_NONE:
UNW_DPRINT(1, "%s+0x%lx", unw.preg_name[r - sr.curr.reg], r->val);
break;
default:
UNW_DPRINT(1, "BADWHERE(%d)", r->where);
break;
}
UNW_DPRINT(1, "\t\t%d\n", r->when);
}
}
#endif
STAT(unw.stat.script.parse_time += ia64_get_itc() - parse_start);
/* translate state record into unwinder instructions: */
/*
* First, set psp if we're dealing with a fixed-size frame;
* subsequent instructions may depend on this value.
*/
if (sr.when_target > sr.curr.reg[UNW_REG_PSP].when
&& (sr.curr.reg[UNW_REG_PSP].where == UNW_WHERE_NONE)
&& sr.curr.reg[UNW_REG_PSP].val != 0) {
/* new psp is sp plus frame size */
insn.opc = UNW_INSN_ADD;
insn.dst = offsetof(struct unw_frame_info, psp)/8;
insn.val = sr.curr.reg[UNW_REG_PSP].val; /* frame size */
script_emit(script, insn);
}
/* determine where the primary UNaT is: */
if (sr.when_target < sr.curr.reg[UNW_REG_PRI_UNAT_GR].when)
i = UNW_REG_PRI_UNAT_MEM;
else if (sr.when_target < sr.curr.reg[UNW_REG_PRI_UNAT_MEM].when)
i = UNW_REG_PRI_UNAT_GR;
else if (sr.curr.reg[UNW_REG_PRI_UNAT_MEM].when > sr.curr.reg[UNW_REG_PRI_UNAT_GR].when)
i = UNW_REG_PRI_UNAT_MEM;
else
i = UNW_REG_PRI_UNAT_GR;
compile_reg(&sr, i, script);
for (i = UNW_REG_BSP; i < UNW_NUM_REGS; ++i)
compile_reg(&sr, i, script);
/* free labeled register states & stack: */
STAT(parse_start = ia64_get_itc());
for (ls = sr.labeled_states; ls; ls = next) {
next = ls->next;
free_state_stack(&ls->saved_state);
free_labeled_state(ls);
}
free_state_stack(&sr.curr);
STAT(unw.stat.script.parse_time += ia64_get_itc() - parse_start);
script_finalize(script, &sr);
STAT(unw.stat.script.build_time += ia64_get_itc() - start);
return script;
}
/*
* Apply the unwinding actions represented by OPS and update SR to
* reflect the state that existed upon entry to the function that this
* unwinder represents.
*/
static inline void
run_script (struct unw_script *script, struct unw_frame_info *state)
{
struct unw_insn *ip, *limit, next_insn;
unsigned long opc, dst, val, off;
unsigned long *s = (unsigned long *) state;
STAT(unsigned long start;)
STAT(++unw.stat.script.runs; start = ia64_get_itc());
state->flags = script->flags;
ip = script->insn;
limit = script->insn + script->count;
next_insn = *ip;
while (ip++ < limit) {
opc = next_insn.opc;
dst = next_insn.dst;
val = next_insn.val;
next_insn = *ip;
redo:
switch (opc) {
case UNW_INSN_ADD:
s[dst] += val;
break;
case UNW_INSN_MOVE2:
if (!s[val])
goto lazy_init;
s[dst+1] = s[val+1];
s[dst] = s[val];
break;
case UNW_INSN_MOVE:
if (!s[val])
goto lazy_init;
s[dst] = s[val];
break;
case UNW_INSN_MOVE_SCRATCH:
if (state->pt) {
s[dst] = (unsigned long) get_scratch_regs(state) + val;
} else {
s[dst] = 0;
UNW_DPRINT(0, "unwind.%s: no state->pt, dst=%ld, val=%ld\n",
__FUNCTION__, dst, val);
}
break;
case UNW_INSN_MOVE_CONST:
if (val == 0)
s[dst] = (unsigned long) &unw.r0;
else {
s[dst] = 0;
UNW_DPRINT(0, "unwind.%s: UNW_INSN_MOVE_CONST bad val=%ld\n",
__FUNCTION__, val);
}
break;
case UNW_INSN_MOVE_STACKED:
s[dst] = (unsigned long) ia64_rse_skip_regs((unsigned long *)state->bsp,
val);
break;
case UNW_INSN_ADD_PSP:
s[dst] = state->psp + val;
break;
case UNW_INSN_ADD_SP:
s[dst] = state->sp + val;
break;
case UNW_INSN_SETNAT_MEMSTK:
if (!state->pri_unat_loc)
state->pri_unat_loc = &state->sw->caller_unat;
/* register off. is a multiple of 8, so the least 3 bits (type) are 0 */
s[dst+1] = ((unsigned long) state->pri_unat_loc - s[dst]) | UNW_NAT_MEMSTK;
break;
case UNW_INSN_SETNAT_TYPE:
s[dst+1] = val;
break;
case UNW_INSN_LOAD:
#ifdef UNW_DEBUG
if ((s[val] & (local_cpu_data->unimpl_va_mask | 0x7)) != 0
|| s[val] < TASK_SIZE)
{
UNW_DPRINT(0, "unwind.%s: rejecting bad psp=0x%lx\n",
__FUNCTION__, s[val]);
break;
}
#endif
s[dst] = *(unsigned long *) s[val];
break;
}
}
STAT(unw.stat.script.run_time += ia64_get_itc() - start);
return;
lazy_init:
off = unw.sw_off[val];
s[val] = (unsigned long) state->sw + off;
if (off >= offsetof(struct switch_stack, r4) && off <= offsetof(struct switch_stack, r7))
/*
* We're initializing a general register: init NaT info, too. Note that
* the offset is a multiple of 8 which gives us the 3 bits needed for
* the type field.
*/
s[val+1] = (offsetof(struct switch_stack, ar_unat) - off) | UNW_NAT_MEMSTK;
goto redo;
}
static int
find_save_locs (struct unw_frame_info *info)
{
int have_write_lock = 0;
struct unw_script *scr;
unsigned long flags = 0;
if ((info->ip & (local_cpu_data->unimpl_va_mask | 0xf)) || info->ip < TASK_SIZE) {
/* don't let obviously bad addresses pollute the cache */
/* FIXME: should really be level 0 but it occurs too often. KAO */
UNW_DPRINT(1, "unwind.%s: rejecting bad ip=0x%lx\n", __FUNCTION__, info->ip);
info->rp_loc = NULL;
return -1;
}
scr = script_lookup(info);
if (!scr) {
spin_lock_irqsave(&unw.lock, flags);
scr = build_script(info);
if (!scr) {
spin_unlock_irqrestore(&unw.lock, flags);
UNW_DPRINT(0,
"unwind.%s: failed to locate/build unwind script for ip %lx\n",
__FUNCTION__, info->ip);
return -1;
}
have_write_lock = 1;
}
info->hint = scr->hint;
info->prev_script = scr - unw.cache;
run_script(scr, info);
if (have_write_lock) {
write_unlock(&scr->lock);
spin_unlock_irqrestore(&unw.lock, flags);
} else
read_unlock(&scr->lock);
return 0;
}
int
unw_unwind (struct unw_frame_info *info)
{
unsigned long prev_ip, prev_sp, prev_bsp;
unsigned long ip, pr, num_regs;
STAT(unsigned long start, flags;)
int retval;
STAT(local_irq_save(flags); ++unw.stat.api.unwinds; start = ia64_get_itc());
prev_ip = info->ip;
prev_sp = info->sp;
prev_bsp = info->bsp;
/* restore the ip */
if (!info->rp_loc) {
/* FIXME: should really be level 0 but it occurs too often. KAO */
UNW_DPRINT(1, "unwind.%s: failed to locate return link (ip=0x%lx)!\n",
__FUNCTION__, info->ip);
STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
return -1;
}
ip = info->ip = *info->rp_loc;
if (ip < GATE_ADDR) {
UNW_DPRINT(2, "unwind.%s: reached user-space (ip=0x%lx)\n", __FUNCTION__, ip);
STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
return -1;
}
/* restore the cfm: */
if (!info->pfs_loc) {
UNW_DPRINT(0, "unwind.%s: failed to locate ar.pfs!\n", __FUNCTION__);
STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
return -1;
}
info->cfm_loc = info->pfs_loc;
/* restore the bsp: */
pr = info->pr;
num_regs = 0;
if ((info->flags & UNW_FLAG_INTERRUPT_FRAME)) {
info->pt = info->sp + 16;
if ((pr & (1UL << PRED_NON_SYSCALL)) != 0)
num_regs = *info->cfm_loc & 0x7f; /* size of frame */
info->pfs_loc =
(unsigned long *) (info->pt + offsetof(struct pt_regs, ar_pfs));
UNW_DPRINT(3, "unwind.%s: interrupt_frame pt 0x%lx\n", __FUNCTION__, info->pt);
} else
num_regs = (*info->cfm_loc >> 7) & 0x7f; /* size of locals */
info->bsp = (unsigned long) ia64_rse_skip_regs((unsigned long *) info->bsp, -num_regs);
if (info->bsp < info->regstk.limit || info->bsp > info->regstk.top) {
UNW_DPRINT(0, "unwind.%s: bsp (0x%lx) out of range [0x%lx-0x%lx]\n",
__FUNCTION__, info->bsp, info->regstk.limit, info->regstk.top);
STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
return -1;
}
/* restore the sp: */
info->sp = info->psp;
if (info->sp < info->memstk.top || info->sp > info->memstk.limit) {
UNW_DPRINT(0, "unwind.%s: sp (0x%lx) out of range [0x%lx-0x%lx]\n",
__FUNCTION__, info->sp, info->memstk.top, info->memstk.limit);
STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
return -1;
}
if (info->ip == prev_ip && info->sp == prev_sp && info->bsp == prev_bsp) {
UNW_DPRINT(0, "unwind.%s: ip, sp, bsp unchanged; stopping here (ip=0x%lx)\n",
__FUNCTION__, ip);
STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
return -1;
}
/* as we unwind, the saved ar.unat becomes the primary unat: */
info->pri_unat_loc = info->unat_loc;
/* finally, restore the predicates: */
unw_get_pr(info, &info->pr);
retval = find_save_locs(info);
STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
return retval;
}
EXPORT_SYMBOL(unw_unwind);
int
unw_unwind_to_user (struct unw_frame_info *info)
{
unsigned long ip, sp, pr = info->pr;
do {
unw_get_sp(info, &sp);
if ((long)((unsigned long)info->task + IA64_STK_OFFSET - sp)
< IA64_PT_REGS_SIZE) {
UNW_DPRINT(0, "unwind.%s: ran off the top of the kernel stack\n",
__FUNCTION__);
break;
}
if (unw_is_intr_frame(info) &&
(pr & (1UL << PRED_USER_STACK)))
return 0;
if (unw_get_pr (info, &pr) < 0) {
unw_get_rp(info, &ip);
UNW_DPRINT(0, "unwind.%s: failed to read "
"predicate register (ip=0x%lx)\n",
__FUNCTION__, ip);
return -1;
}
} while (unw_unwind(info) >= 0);
unw_get_ip(info, &ip);
UNW_DPRINT(0, "unwind.%s: failed to unwind to user-level (ip=0x%lx)\n",
__FUNCTION__, ip);
return -1;
}
EXPORT_SYMBOL(unw_unwind_to_user);
static void
init_frame_info (struct unw_frame_info *info, struct task_struct *t,
struct switch_stack *sw, unsigned long stktop)
{
unsigned long rbslimit, rbstop, stklimit;
STAT(unsigned long start, flags;)
STAT(local_irq_save(flags); ++unw.stat.api.inits; start = ia64_get_itc());
/*
* Subtle stuff here: we _could_ unwind through the switch_stack frame but we
* don't want to do that because it would be slow as each preserved register would
* have to be processed. Instead, what we do here is zero out the frame info and
* start the unwind process at the function that created the switch_stack frame.
* When a preserved value in switch_stack needs to be accessed, run_script() will
* initialize the appropriate pointer on demand.
*/
memset(info, 0, sizeof(*info));
rbslimit = (unsigned long) t + IA64_RBS_OFFSET;
rbstop = sw->ar_bspstore;
if (rbstop - (unsigned long) t >= IA64_STK_OFFSET)
rbstop = rbslimit;
stklimit = (unsigned long) t + IA64_STK_OFFSET;
if (stktop <= rbstop)
stktop = rbstop;
info->regstk.limit = rbslimit;
info->regstk.top = rbstop;
info->memstk.limit = stklimit;
info->memstk.top = stktop;
info->task = t;
info->sw = sw;
info->sp = info->psp = stktop;
info->pr = sw->pr;
UNW_DPRINT(3, "unwind.%s:\n"
" task 0x%lx\n"
" rbs = [0x%lx-0x%lx)\n"
" stk = [0x%lx-0x%lx)\n"
" pr 0x%lx\n"
" sw 0x%lx\n"
" sp 0x%lx\n",
__FUNCTION__, (unsigned long) t, rbslimit, rbstop, stktop, stklimit,
info->pr, (unsigned long) info->sw, info->sp);
STAT(unw.stat.api.init_time += ia64_get_itc() - start; local_irq_restore(flags));
}
void
unw_init_frame_info (struct unw_frame_info *info, struct task_struct *t, struct switch_stack *sw)
{
unsigned long sol;
init_frame_info(info, t, sw, (unsigned long) (sw + 1) - 16);
info->cfm_loc = &sw->ar_pfs;
sol = (*info->cfm_loc >> 7) & 0x7f;
info->bsp = (unsigned long) ia64_rse_skip_regs((unsigned long *) info->regstk.top, -sol);
info->ip = sw->b0;
UNW_DPRINT(3, "unwind.%s:\n"
" bsp 0x%lx\n"
" sol 0x%lx\n"
" ip 0x%lx\n",
__FUNCTION__, info->bsp, sol, info->ip);
find_save_locs(info);
}
EXPORT_SYMBOL(unw_init_frame_info);
void
unw_init_from_blocked_task (struct unw_frame_info *info, struct task_struct *t)
{
struct switch_stack *sw = (struct switch_stack *) (t->thread.ksp + 16);
UNW_DPRINT(1, "unwind.%s\n", __FUNCTION__);
unw_init_frame_info(info, t, sw);
}
EXPORT_SYMBOL(unw_init_from_blocked_task);
static void
init_unwind_table (struct unw_table *table, const char *name, unsigned long segment_base,
unsigned long gp, const void *table_start, const void *table_end)
{
const struct unw_table_entry *start = table_start, *end = table_end;
table->name = name;
table->segment_base = segment_base;
table->gp = gp;
table->start = segment_base + start[0].start_offset;
table->end = segment_base + end[-1].end_offset;
table->array = start;
table->length = end - start;
}
void *
unw_add_unwind_table (const char *name, unsigned long segment_base, unsigned long gp,
const void *table_start, const void *table_end)
{
const struct unw_table_entry *start = table_start, *end = table_end;
struct unw_table *table;
unsigned long flags;
if (end - start <= 0) {
UNW_DPRINT(0, "unwind.%s: ignoring attempt to insert empty unwind table\n",
__FUNCTION__);
return NULL;
}
table = kmalloc(sizeof(*table), GFP_USER);
if (!table)
return NULL;
init_unwind_table(table, name, segment_base, gp, table_start, table_end);
spin_lock_irqsave(&unw.lock, flags);
{
/* keep kernel unwind table at the front (it's searched most commonly): */
table->next = unw.tables->next;
unw.tables->next = table;
}
spin_unlock_irqrestore(&unw.lock, flags);
return table;
}
void
unw_remove_unwind_table (void *handle)
{
struct unw_table *table, *prev;
struct unw_script *tmp;
unsigned long flags;
long index;
if (!handle) {
UNW_DPRINT(0, "unwind.%s: ignoring attempt to remove non-existent unwind table\n",
__FUNCTION__);
return;
}
table = handle;
if (table == &unw.kernel_table) {
UNW_DPRINT(0, "unwind.%s: sorry, freeing the kernel's unwind table is a "
"no-can-do!\n", __FUNCTION__);
return;
}
spin_lock_irqsave(&unw.lock, flags);
{
/* first, delete the table: */
for (prev = (struct unw_table *) &unw.tables; prev; prev = prev->next)
if (prev->next == table)
break;
if (!prev) {
UNW_DPRINT(0, "unwind.%s: failed to find unwind table %p\n",
__FUNCTION__, (void *) table);
spin_unlock_irqrestore(&unw.lock, flags);
return;
}
prev->next = table->next;
}
spin_unlock_irqrestore(&unw.lock, flags);
/* next, remove hash table entries for this table */
for (index = 0; index <= UNW_HASH_SIZE; ++index) {
tmp = unw.cache + unw.hash[index];
if (unw.hash[index] >= UNW_CACHE_SIZE
|| tmp->ip < table->start || tmp->ip >= table->end)
continue;
write_lock(&tmp->lock);
{
if (tmp->ip >= table->start && tmp->ip < table->end) {
unw.hash[index] = tmp->coll_chain;
tmp->ip = 0;
}
}
write_unlock(&tmp->lock);
}
kfree(table);
}
static int __init
create_gate_table (void)
{
const struct unw_table_entry *entry, *start, *end;
unsigned long *lp, segbase = GATE_ADDR;
size_t info_size, size;
char *info;
Elf64_Phdr *punw = NULL, *phdr = (Elf64_Phdr *) (GATE_ADDR + GATE_EHDR->e_phoff);
int i;
for (i = 0; i < GATE_EHDR->e_phnum; ++i, ++phdr)
if (phdr->p_type == PT_IA_64_UNWIND) {
punw = phdr;
break;
}
if (!punw) {
printk("%s: failed to find gate DSO's unwind table!\n", __FUNCTION__);
return 0;
}
start = (const struct unw_table_entry *) punw->p_vaddr;
end = (struct unw_table_entry *) ((char *) start + punw->p_memsz);
size = 0;
unw_add_unwind_table("linux-gate.so", segbase, 0, start, end);
for (entry = start; entry < end; ++entry)
size += 3*8 + 8 + 8*UNW_LENGTH(*(u64 *) (segbase + entry->info_offset));
size += 8; /* reserve space for "end of table" marker */
unw.gate_table = kmalloc(size, GFP_KERNEL);
if (!unw.gate_table) {
unw.gate_table_size = 0;
printk(KERN_ERR "%s: unable to create unwind data for gate page!\n", __FUNCTION__);
return 0;
}
unw.gate_table_size = size;
lp = unw.gate_table;
info = (char *) unw.gate_table + size;
for (entry = start; entry < end; ++entry, lp += 3) {
info_size = 8 + 8*UNW_LENGTH(*(u64 *) (segbase + entry->info_offset));
info -= info_size;
memcpy(info, (char *) segbase + entry->info_offset, info_size);
lp[0] = segbase + entry->start_offset; /* start */
lp[1] = segbase + entry->end_offset; /* end */
lp[2] = info - (char *) unw.gate_table; /* info */
}
*lp = 0; /* end-of-table marker */
return 0;
}
__initcall(create_gate_table);
void __init
unw_init (void)
{
extern char __gp[];
extern void unw_hash_index_t_is_too_narrow (void);
long i, off;
if (8*sizeof(unw_hash_index_t) < UNW_LOG_HASH_SIZE)
unw_hash_index_t_is_too_narrow();
unw.sw_off[unw.preg_index[UNW_REG_PRI_UNAT_GR]] = SW(CALLER_UNAT);
unw.sw_off[unw.preg_index[UNW_REG_BSPSTORE]] = SW(AR_BSPSTORE);
unw.sw_off[unw.preg_index[UNW_REG_PFS]] = SW(AR_PFS);
unw.sw_off[unw.preg_index[UNW_REG_RP]] = SW(B0);
unw.sw_off[unw.preg_index[UNW_REG_UNAT]] = SW(CALLER_UNAT);
unw.sw_off[unw.preg_index[UNW_REG_PR]] = SW(PR);
unw.sw_off[unw.preg_index[UNW_REG_LC]] = SW(AR_LC);
unw.sw_off[unw.preg_index[UNW_REG_FPSR]] = SW(AR_FPSR);
for (i = UNW_REG_R4, off = SW(R4); i <= UNW_REG_R7; ++i, off += 8)
unw.sw_off[unw.preg_index[i]] = off;
for (i = UNW_REG_B1, off = SW(B1); i <= UNW_REG_B5; ++i, off += 8)
unw.sw_off[unw.preg_index[i]] = off;
for (i = UNW_REG_F2, off = SW(F2); i <= UNW_REG_F5; ++i, off += 16)
unw.sw_off[unw.preg_index[i]] = off;
for (i = UNW_REG_F16, off = SW(F16); i <= UNW_REG_F31; ++i, off += 16)
unw.sw_off[unw.preg_index[i]] = off;
for (i = 0; i < UNW_CACHE_SIZE; ++i) {
if (i > 0)
unw.cache[i].lru_chain = (i - 1);
unw.cache[i].coll_chain = -1;
rwlock_init(&unw.cache[i].lock);
}
unw.lru_head = UNW_CACHE_SIZE - 1;
unw.lru_tail = 0;
init_unwind_table(&unw.kernel_table, "kernel", KERNEL_START, (unsigned long) __gp,
__start_unwind, __end_unwind);
}
/*
* DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED
*
* This system call has been deprecated. The new and improved way to get
* at the kernel's unwind info is via the gate DSO. The address of the
* ELF header for this DSO is passed to user-level via AT_SYSINFO_EHDR.
*
* DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED
*
* This system call copies the unwind data into the buffer pointed to by BUF and returns
* the size of the unwind data. If BUF_SIZE is smaller than the size of the unwind data
* or if BUF is NULL, nothing is copied, but the system call still returns the size of the
* unwind data.
*
* The first portion of the unwind data contains an unwind table and rest contains the
* associated unwind info (in no particular order). The unwind table consists of a table
* of entries of the form:
*
* u64 start; (64-bit address of start of function)
* u64 end; (64-bit address of start of function)
* u64 info; (BUF-relative offset to unwind info)
*
* The end of the unwind table is indicated by an entry with a START address of zero.
*
* Please see the IA-64 Software Conventions and Runtime Architecture manual for details
* on the format of the unwind info.
*
* ERRORS
* EFAULT BUF points outside your accessible address space.
*/
asmlinkage long
sys_getunwind (void __user *buf, size_t buf_size)
{
if (buf && buf_size >= unw.gate_table_size)
if (copy_to_user(buf, unw.gate_table, unw.gate_table_size) != 0)
return -EFAULT;
return unw.gate_table_size;
}
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