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linux/arch/ia64/kernel/unwind.c
Gustavo A. R. Silva df561f6688 treewide: Use fallthrough pseudo-keyword 
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00

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// SPDX-License-Identifier: GPL-2.0
/*
* 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 dependent 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/memblock.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 <linux/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", __func__, 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", __func__);
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", __func__, 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",
__func__, 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;
}
}
fallthrough;
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",
__func__, (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", __func__);
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",
__func__);
} 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",
__func__, regnum);
return -1;
}
if (write)
if (read_only(addr)) {
UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n",
__func__);
} 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",
__func__, 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",
__func__);
} 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",
__func__, regnum);
return -1;
}
if (write) {
if (read_only(addr)) {
UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n",
__func__);
} 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",
__func__);
} 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", __func__, 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", __func__);
}
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", __func__);
}
else
UNW_DPRINT(0, "unwind%s: ignoring unwabi(abi=0x%x,context=0x%x)\n",
__func__, 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)
{
/* magic number = ((sqrt(5)-1)/2)*2^64 */
static const unsigned long hashmagic = 0x9e3779b97f4a7c16UL;
return (ip >> 4) * hashmagic >> (64 - UNW_LOG_HASH_SIZE);
}
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",
__func__, 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",
__func__, 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",
__func__, 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",
__func__, 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, *prev;
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", __func__, ip);
script = script_new(ip);
if (!script) {
UNW_DPRINT(0, "unwind.%s: failed to create unwind script\n", __func__);
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());
prev = NULL;
for (table = unw.tables; table; table = table->next) {
if (ip >= table->start && ip < table->end) {
/*
* Leave the kernel unwind table at the very front,
* lest moving it breaks some assumption elsewhere.
* Otherwise, move the matching table to the second
* position in the list so that traversals can benefit
* from commonality in backtrace paths.
*/
if (prev && prev != unw.tables) {
/* unw is safe - we're already spinlocked */
prev->next = table->next;
table->next = unw.tables->next;
unw.tables->next = table;
}
e = lookup(table, ip - table->segment_base);
break;
}
prev = table;
}
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",
__func__, 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",
__func__, 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",
__func__, 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",
__func__, 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",
__func__, 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",
__func__, 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", __func__, 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",
__func__, 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;
}
static int
unw_valid(const struct unw_frame_info *info, unsigned long* p)
{
unsigned long loc = (unsigned long)p;
return (loc >= info->regstk.limit && loc < info->regstk.top) ||
(loc >= info->memstk.top && loc < info->memstk.limit);
}
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;
/* validate the return IP pointer */
if (!unw_valid(info, 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",
__func__, info->ip);
STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
return -1;
}
/* restore the ip */
ip = info->ip = *info->rp_loc;
if (ip < GATE_ADDR) {
UNW_DPRINT(2, "unwind.%s: reached user-space (ip=0x%lx)\n", __func__, ip);
STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
return -1;
}
/* validate the previous stack frame pointer */
if (!unw_valid(info, info->pfs_loc)) {
UNW_DPRINT(0, "unwind.%s: failed to locate ar.pfs!\n", __func__);
STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
return -1;
}
/* restore the cfm: */
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", __func__, 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",
__func__, 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",
__func__, 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",
__func__, 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",
__func__);
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",
__func__, 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",
__func__, 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;
stklimit = (unsigned long) t + IA64_STK_OFFSET;
rbstop = sw->ar_bspstore;
if (rbstop > stklimit || rbstop < rbslimit)
rbstop = rbslimit;
if (stktop <= rbstop)
stktop = rbstop;
if (stktop > stklimit)
stktop = stklimit;
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",
__func__, (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",
__func__, 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", __func__);
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",
__func__);
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",
__func__);
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", __func__);
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",
__func__, (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", __func__);
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", __func__);
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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