420 строки
10 KiB
C
420 строки
10 KiB
C
/*
|
|
* Kernel unwinding support
|
|
*
|
|
* (c) 2002-2004 Randolph Chung <tausq@debian.org>
|
|
*
|
|
* Derived partially from the IA64 implementation. The PA-RISC
|
|
* Runtime Architecture Document is also a useful reference to
|
|
* understand what is happening here
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/kallsyms.h>
|
|
|
|
#include <asm/uaccess.h>
|
|
#include <asm/assembly.h>
|
|
#include <asm/asm-offsets.h>
|
|
#include <asm/ptrace.h>
|
|
|
|
#include <asm/unwind.h>
|
|
|
|
/* #define DEBUG 1 */
|
|
#ifdef DEBUG
|
|
#define dbg(x...) printk(x)
|
|
#else
|
|
#define dbg(x...)
|
|
#endif
|
|
|
|
#define KERNEL_START (KERNEL_BINARY_TEXT_START - 0x1000)
|
|
|
|
extern struct unwind_table_entry __start___unwind[];
|
|
extern struct unwind_table_entry __stop___unwind[];
|
|
|
|
static spinlock_t unwind_lock;
|
|
/*
|
|
* the kernel unwind block is not dynamically allocated so that
|
|
* we can call unwind_init as early in the bootup process as
|
|
* possible (before the slab allocator is initialized)
|
|
*/
|
|
static struct unwind_table kernel_unwind_table __read_mostly;
|
|
static LIST_HEAD(unwind_tables);
|
|
|
|
static inline const struct unwind_table_entry *
|
|
find_unwind_entry_in_table(const struct unwind_table *table, unsigned long addr)
|
|
{
|
|
const struct unwind_table_entry *e = NULL;
|
|
unsigned long lo, hi, mid;
|
|
|
|
lo = 0;
|
|
hi = table->length - 1;
|
|
|
|
while (lo <= hi) {
|
|
mid = (hi - lo) / 2 + lo;
|
|
e = &table->table[mid];
|
|
if (addr < e->region_start)
|
|
hi = mid - 1;
|
|
else if (addr > e->region_end)
|
|
lo = mid + 1;
|
|
else
|
|
return e;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static const struct unwind_table_entry *
|
|
find_unwind_entry(unsigned long addr)
|
|
{
|
|
struct unwind_table *table;
|
|
const struct unwind_table_entry *e = NULL;
|
|
|
|
if (addr >= kernel_unwind_table.start &&
|
|
addr <= kernel_unwind_table.end)
|
|
e = find_unwind_entry_in_table(&kernel_unwind_table, addr);
|
|
else
|
|
list_for_each_entry(table, &unwind_tables, list) {
|
|
if (addr >= table->start &&
|
|
addr <= table->end)
|
|
e = find_unwind_entry_in_table(table, addr);
|
|
if (e)
|
|
break;
|
|
}
|
|
|
|
return e;
|
|
}
|
|
|
|
static void
|
|
unwind_table_init(struct unwind_table *table, const char *name,
|
|
unsigned long base_addr, unsigned long gp,
|
|
void *table_start, void *table_end)
|
|
{
|
|
struct unwind_table_entry *start = table_start;
|
|
struct unwind_table_entry *end =
|
|
(struct unwind_table_entry *)table_end - 1;
|
|
|
|
table->name = name;
|
|
table->base_addr = base_addr;
|
|
table->gp = gp;
|
|
table->start = base_addr + start->region_start;
|
|
table->end = base_addr + end->region_end;
|
|
table->table = (struct unwind_table_entry *)table_start;
|
|
table->length = end - start + 1;
|
|
INIT_LIST_HEAD(&table->list);
|
|
|
|
for (; start <= end; start++) {
|
|
if (start < end &&
|
|
start->region_end > (start+1)->region_start) {
|
|
printk("WARNING: Out of order unwind entry! %p and %p\n", start, start+1);
|
|
}
|
|
|
|
start->region_start += base_addr;
|
|
start->region_end += base_addr;
|
|
}
|
|
}
|
|
|
|
static void
|
|
unwind_table_sort(struct unwind_table_entry *start,
|
|
struct unwind_table_entry *finish)
|
|
{
|
|
struct unwind_table_entry el, *p, *q;
|
|
|
|
for (p = start + 1; p < finish; ++p) {
|
|
if (p[0].region_start < p[-1].region_start) {
|
|
el = *p;
|
|
q = p;
|
|
do {
|
|
q[0] = q[-1];
|
|
--q;
|
|
} while (q > start &&
|
|
el.region_start < q[-1].region_start);
|
|
*q = el;
|
|
}
|
|
}
|
|
}
|
|
|
|
struct unwind_table *
|
|
unwind_table_add(const char *name, unsigned long base_addr,
|
|
unsigned long gp,
|
|
void *start, void *end)
|
|
{
|
|
struct unwind_table *table;
|
|
unsigned long flags;
|
|
struct unwind_table_entry *s = (struct unwind_table_entry *)start;
|
|
struct unwind_table_entry *e = (struct unwind_table_entry *)end;
|
|
|
|
unwind_table_sort(s, e);
|
|
|
|
table = kmalloc(sizeof(struct unwind_table), GFP_USER);
|
|
if (table == NULL)
|
|
return NULL;
|
|
unwind_table_init(table, name, base_addr, gp, start, end);
|
|
spin_lock_irqsave(&unwind_lock, flags);
|
|
list_add_tail(&table->list, &unwind_tables);
|
|
spin_unlock_irqrestore(&unwind_lock, flags);
|
|
|
|
return table;
|
|
}
|
|
|
|
void unwind_table_remove(struct unwind_table *table)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&unwind_lock, flags);
|
|
list_del(&table->list);
|
|
spin_unlock_irqrestore(&unwind_lock, flags);
|
|
|
|
kfree(table);
|
|
}
|
|
|
|
/* Called from setup_arch to import the kernel unwind info */
|
|
int unwind_init(void)
|
|
{
|
|
long start, stop;
|
|
register unsigned long gp __asm__ ("r27");
|
|
|
|
start = (long)&__start___unwind[0];
|
|
stop = (long)&__stop___unwind[0];
|
|
|
|
spin_lock_init(&unwind_lock);
|
|
|
|
printk("unwind_init: start = 0x%lx, end = 0x%lx, entries = %lu\n",
|
|
start, stop,
|
|
(stop - start) / sizeof(struct unwind_table_entry));
|
|
|
|
unwind_table_init(&kernel_unwind_table, "kernel", KERNEL_START,
|
|
gp,
|
|
&__start___unwind[0], &__stop___unwind[0]);
|
|
#if 0
|
|
{
|
|
int i;
|
|
for (i = 0; i < 10; i++)
|
|
{
|
|
printk("region 0x%x-0x%x\n",
|
|
__start___unwind[i].region_start,
|
|
__start___unwind[i].region_end);
|
|
}
|
|
}
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_64BIT
|
|
#define get_func_addr(fptr) fptr[2]
|
|
#else
|
|
#define get_func_addr(fptr) fptr[0]
|
|
#endif
|
|
|
|
static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int frame_size)
|
|
{
|
|
extern void handle_interruption(int, struct pt_regs *);
|
|
static unsigned long *hi = (unsigned long *)&handle_interruption;
|
|
|
|
if (pc == get_func_addr(hi)) {
|
|
struct pt_regs *regs = (struct pt_regs *)(info->sp - frame_size - PT_SZ_ALGN);
|
|
dbg("Unwinding through handle_interruption()\n");
|
|
info->prev_sp = regs->gr[30];
|
|
info->prev_ip = regs->iaoq[0];
|
|
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void unwind_frame_regs(struct unwind_frame_info *info)
|
|
{
|
|
const struct unwind_table_entry *e;
|
|
unsigned long npc;
|
|
unsigned int insn;
|
|
long frame_size = 0;
|
|
int looking_for_rp, rpoffset = 0;
|
|
|
|
e = find_unwind_entry(info->ip);
|
|
if (e == NULL) {
|
|
unsigned long sp;
|
|
extern char _stext[], _etext[];
|
|
|
|
dbg("Cannot find unwind entry for 0x%lx; forced unwinding\n", info->ip);
|
|
|
|
#ifdef CONFIG_KALLSYMS
|
|
/* Handle some frequent special cases.... */
|
|
{
|
|
char symname[KSYM_NAME_LEN];
|
|
char *modname;
|
|
|
|
kallsyms_lookup(info->ip, NULL, NULL, &modname,
|
|
symname);
|
|
|
|
dbg("info->ip = 0x%lx, name = %s\n", info->ip, symname);
|
|
|
|
if (strcmp(symname, "_switch_to_ret") == 0) {
|
|
info->prev_sp = info->sp - CALLEE_SAVE_FRAME_SIZE;
|
|
info->prev_ip = *(unsigned long *)(info->prev_sp - RP_OFFSET);
|
|
dbg("_switch_to_ret @ %lx - setting "
|
|
"prev_sp=%lx prev_ip=%lx\n",
|
|
info->ip, info->prev_sp,
|
|
info->prev_ip);
|
|
return;
|
|
} else if (strcmp(symname, "ret_from_kernel_thread") == 0 ||
|
|
strcmp(symname, "syscall_exit") == 0) {
|
|
info->prev_ip = info->prev_sp = 0;
|
|
return;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* Since we are doing the unwinding blind, we don't know if
|
|
we are adjusting the stack correctly or extracting the rp
|
|
correctly. The rp is checked to see if it belongs to the
|
|
kernel text section, if not we assume we don't have a
|
|
correct stack frame and we continue to unwind the stack.
|
|
This is not quite correct, and will fail for loadable
|
|
modules. */
|
|
sp = info->sp & ~63;
|
|
do {
|
|
unsigned long tmp;
|
|
|
|
info->prev_sp = sp - 64;
|
|
info->prev_ip = 0;
|
|
if (get_user(tmp, (unsigned long *)(info->prev_sp - RP_OFFSET)))
|
|
break;
|
|
info->prev_ip = tmp;
|
|
sp = info->prev_sp;
|
|
} while (info->prev_ip < (unsigned long)_stext ||
|
|
info->prev_ip > (unsigned long)_etext);
|
|
|
|
info->rp = 0;
|
|
|
|
dbg("analyzing func @ %lx with no unwind info, setting "
|
|
"prev_sp=%lx prev_ip=%lx\n", info->ip,
|
|
info->prev_sp, info->prev_ip);
|
|
} else {
|
|
dbg("e->start = 0x%x, e->end = 0x%x, Save_SP = %d, "
|
|
"Save_RP = %d, Millicode = %d size = %u\n",
|
|
e->region_start, e->region_end, e->Save_SP, e->Save_RP,
|
|
e->Millicode, e->Total_frame_size);
|
|
|
|
looking_for_rp = e->Save_RP;
|
|
|
|
for (npc = e->region_start;
|
|
(frame_size < (e->Total_frame_size << 3) ||
|
|
looking_for_rp) &&
|
|
npc < info->ip;
|
|
npc += 4) {
|
|
|
|
insn = *(unsigned int *)npc;
|
|
|
|
if ((insn & 0xffffc000) == 0x37de0000 ||
|
|
(insn & 0xffe00000) == 0x6fc00000) {
|
|
/* ldo X(sp), sp, or stwm X,D(sp) */
|
|
frame_size += (insn & 0x1 ? -1 << 13 : 0) |
|
|
((insn & 0x3fff) >> 1);
|
|
dbg("analyzing func @ %lx, insn=%08x @ "
|
|
"%lx, frame_size = %ld\n", info->ip,
|
|
insn, npc, frame_size);
|
|
} else if ((insn & 0xffe00008) == 0x73c00008) {
|
|
/* std,ma X,D(sp) */
|
|
frame_size += (insn & 0x1 ? -1 << 13 : 0) |
|
|
(((insn >> 4) & 0x3ff) << 3);
|
|
dbg("analyzing func @ %lx, insn=%08x @ "
|
|
"%lx, frame_size = %ld\n", info->ip,
|
|
insn, npc, frame_size);
|
|
} else if (insn == 0x6bc23fd9) {
|
|
/* stw rp,-20(sp) */
|
|
rpoffset = 20;
|
|
looking_for_rp = 0;
|
|
dbg("analyzing func @ %lx, insn=stw rp,"
|
|
"-20(sp) @ %lx\n", info->ip, npc);
|
|
} else if (insn == 0x0fc212c1) {
|
|
/* std rp,-16(sr0,sp) */
|
|
rpoffset = 16;
|
|
looking_for_rp = 0;
|
|
dbg("analyzing func @ %lx, insn=std rp,"
|
|
"-16(sp) @ %lx\n", info->ip, npc);
|
|
}
|
|
}
|
|
|
|
if (!unwind_special(info, e->region_start, frame_size)) {
|
|
info->prev_sp = info->sp - frame_size;
|
|
if (e->Millicode)
|
|
info->rp = info->r31;
|
|
else if (rpoffset)
|
|
info->rp = *(unsigned long *)(info->prev_sp - rpoffset);
|
|
info->prev_ip = info->rp;
|
|
info->rp = 0;
|
|
}
|
|
|
|
dbg("analyzing func @ %lx, setting prev_sp=%lx "
|
|
"prev_ip=%lx npc=%lx\n", info->ip, info->prev_sp,
|
|
info->prev_ip, npc);
|
|
}
|
|
}
|
|
|
|
void unwind_frame_init(struct unwind_frame_info *info, struct task_struct *t,
|
|
struct pt_regs *regs)
|
|
{
|
|
memset(info, 0, sizeof(struct unwind_frame_info));
|
|
info->t = t;
|
|
info->sp = regs->gr[30];
|
|
info->ip = regs->iaoq[0];
|
|
info->rp = regs->gr[2];
|
|
info->r31 = regs->gr[31];
|
|
|
|
dbg("(%d) Start unwind from sp=%08lx ip=%08lx\n",
|
|
t ? (int)t->pid : -1, info->sp, info->ip);
|
|
}
|
|
|
|
void unwind_frame_init_from_blocked_task(struct unwind_frame_info *info, struct task_struct *t)
|
|
{
|
|
struct pt_regs *r = &t->thread.regs;
|
|
struct pt_regs *r2;
|
|
|
|
r2 = kmalloc(sizeof(struct pt_regs), GFP_ATOMIC);
|
|
if (!r2)
|
|
return;
|
|
*r2 = *r;
|
|
r2->gr[30] = r->ksp;
|
|
r2->iaoq[0] = r->kpc;
|
|
unwind_frame_init(info, t, r2);
|
|
kfree(r2);
|
|
}
|
|
|
|
void unwind_frame_init_running(struct unwind_frame_info *info, struct pt_regs *regs)
|
|
{
|
|
unwind_frame_init(info, current, regs);
|
|
}
|
|
|
|
int unwind_once(struct unwind_frame_info *next_frame)
|
|
{
|
|
unwind_frame_regs(next_frame);
|
|
|
|
if (next_frame->prev_sp == 0 ||
|
|
next_frame->prev_ip == 0)
|
|
return -1;
|
|
|
|
next_frame->sp = next_frame->prev_sp;
|
|
next_frame->ip = next_frame->prev_ip;
|
|
next_frame->prev_sp = 0;
|
|
next_frame->prev_ip = 0;
|
|
|
|
dbg("(%d) Continue unwind to sp=%08lx ip=%08lx\n",
|
|
next_frame->t ? (int)next_frame->t->pid : -1,
|
|
next_frame->sp, next_frame->ip);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int unwind_to_user(struct unwind_frame_info *info)
|
|
{
|
|
int ret;
|
|
|
|
do {
|
|
ret = unwind_once(info);
|
|
} while (!ret && !(info->ip & 3));
|
|
|
|
return ret;
|
|
}
|