You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
326 lines
8.4 KiB
326 lines
8.4 KiB
/*
|
|
* arch/sh64/kernel/unwind.c
|
|
*
|
|
* Copyright (C) 2004 Paul Mundt
|
|
* Copyright (C) 2004 Richard Curnow
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive
|
|
* for more details.
|
|
*/
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/types.h>
|
|
#include <linux/errno.h>
|
|
#include <asm/page.h>
|
|
#include <asm/ptrace.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/io.h>
|
|
|
|
static u8 regcache[63];
|
|
|
|
/*
|
|
* Finding the previous stack frame isn't horribly straightforward as it is
|
|
* on some other platforms. In the sh64 case, we don't have "linked" stack
|
|
* frames, so we need to do a bit of work to determine the previous frame,
|
|
* and in turn, the previous r14/r18 pair.
|
|
*
|
|
* There are generally a few cases which determine where we can find out
|
|
* the r14/r18 values. In the general case, this can be determined by poking
|
|
* around the prologue of the symbol PC is in (note that we absolutely must
|
|
* have frame pointer support as well as the kernel symbol table mapped,
|
|
* otherwise we can't even get this far).
|
|
*
|
|
* In other cases, such as the interrupt/exception path, we can poke around
|
|
* the sp/fp.
|
|
*
|
|
* Notably, this entire approach is somewhat error prone, and in the event
|
|
* that the previous frame cannot be determined, that's all we can do.
|
|
* Either way, this still leaves us with a more correct backtrace then what
|
|
* we would be able to come up with by walking the stack (which is garbage
|
|
* for anything beyond the first frame).
|
|
* -- PFM.
|
|
*/
|
|
static int lookup_prev_stack_frame(unsigned long fp, unsigned long pc,
|
|
unsigned long *pprev_fp, unsigned long *pprev_pc,
|
|
struct pt_regs *regs)
|
|
{
|
|
const char *sym;
|
|
char *modname, namebuf[128];
|
|
unsigned long offset, size;
|
|
unsigned long prologue = 0;
|
|
unsigned long fp_displacement = 0;
|
|
unsigned long fp_prev = 0;
|
|
unsigned long offset_r14 = 0, offset_r18 = 0;
|
|
int i, found_prologue_end = 0;
|
|
|
|
sym = kallsyms_lookup(pc, &size, &offset, &modname, namebuf);
|
|
if (!sym)
|
|
return -EINVAL;
|
|
|
|
prologue = pc - offset;
|
|
if (!prologue)
|
|
return -EINVAL;
|
|
|
|
/* Validate fp, to avoid risk of dereferencing a bad pointer later.
|
|
Assume 128Mb since that's the amount of RAM on a Cayman. Modify
|
|
when there is an SH-5 board with more. */
|
|
if ((fp < (unsigned long) phys_to_virt(__MEMORY_START)) ||
|
|
(fp >= (unsigned long)(phys_to_virt(__MEMORY_START)) + 128*1024*1024) ||
|
|
((fp & 7) != 0)) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Depth to walk, depth is completely arbitrary.
|
|
*/
|
|
for (i = 0; i < 100; i++, prologue += sizeof(unsigned long)) {
|
|
unsigned long op;
|
|
u8 major, minor;
|
|
u8 src, dest, disp;
|
|
|
|
op = *(unsigned long *)prologue;
|
|
|
|
major = (op >> 26) & 0x3f;
|
|
src = (op >> 20) & 0x3f;
|
|
minor = (op >> 16) & 0xf;
|
|
disp = (op >> 10) & 0x3f;
|
|
dest = (op >> 4) & 0x3f;
|
|
|
|
/*
|
|
* Stack frame creation happens in a number of ways.. in the
|
|
* general case when the stack frame is less than 511 bytes,
|
|
* it's generally created by an addi or addi.l:
|
|
*
|
|
* addi/addi.l r15, -FRAME_SIZE, r15
|
|
*
|
|
* in the event that the frame size is bigger than this, it's
|
|
* typically created using a movi/sub pair as follows:
|
|
*
|
|
* movi FRAME_SIZE, rX
|
|
* sub r15, rX, r15
|
|
*/
|
|
|
|
switch (major) {
|
|
case (0x00 >> 2):
|
|
switch (minor) {
|
|
case 0x8: /* add.l */
|
|
case 0x9: /* add */
|
|
/* Look for r15, r63, r14 */
|
|
if (src == 15 && disp == 63 && dest == 14)
|
|
found_prologue_end = 1;
|
|
|
|
break;
|
|
case 0xa: /* sub.l */
|
|
case 0xb: /* sub */
|
|
if (src != 15 || dest != 15)
|
|
continue;
|
|
|
|
fp_displacement -= regcache[disp];
|
|
fp_prev = fp - fp_displacement;
|
|
break;
|
|
}
|
|
break;
|
|
case (0xa8 >> 2): /* st.l */
|
|
if (src != 15)
|
|
continue;
|
|
|
|
switch (dest) {
|
|
case 14:
|
|
if (offset_r14 || fp_displacement == 0)
|
|
continue;
|
|
|
|
offset_r14 = (u64)(((((s64)op >> 10) & 0x3ff) << 54) >> 54);
|
|
offset_r14 *= sizeof(unsigned long);
|
|
offset_r14 += fp_displacement;
|
|
break;
|
|
case 18:
|
|
if (offset_r18 || fp_displacement == 0)
|
|
continue;
|
|
|
|
offset_r18 = (u64)(((((s64)op >> 10) & 0x3ff) << 54) >> 54);
|
|
offset_r18 *= sizeof(unsigned long);
|
|
offset_r18 += fp_displacement;
|
|
break;
|
|
}
|
|
|
|
break;
|
|
case (0xcc >> 2): /* movi */
|
|
if (dest >= 63) {
|
|
printk(KERN_NOTICE "%s: Invalid dest reg %d "
|
|
"specified in movi handler. Failed "
|
|
"opcode was 0x%lx: ", __FUNCTION__,
|
|
dest, op);
|
|
|
|
continue;
|
|
}
|
|
|
|
/* Sign extend */
|
|
regcache[dest] =
|
|
((((s64)(u64)op >> 10) & 0xffff) << 54) >> 54;
|
|
break;
|
|
case (0xd0 >> 2): /* addi */
|
|
case (0xd4 >> 2): /* addi.l */
|
|
/* Look for r15, -FRAME_SIZE, r15 */
|
|
if (src != 15 || dest != 15)
|
|
continue;
|
|
|
|
/* Sign extended frame size.. */
|
|
fp_displacement +=
|
|
(u64)(((((s64)op >> 10) & 0x3ff) << 54) >> 54);
|
|
fp_prev = fp - fp_displacement;
|
|
break;
|
|
}
|
|
|
|
if (found_prologue_end && offset_r14 && (offset_r18 || *pprev_pc) && fp_prev)
|
|
break;
|
|
}
|
|
|
|
if (offset_r14 == 0 || fp_prev == 0) {
|
|
if (!offset_r14)
|
|
pr_debug("Unable to find r14 offset\n");
|
|
if (!fp_prev)
|
|
pr_debug("Unable to find previous fp\n");
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* For innermost leaf function, there might not be a offset_r18 */
|
|
if (!*pprev_pc && (offset_r18 == 0))
|
|
return -EINVAL;
|
|
|
|
*pprev_fp = *(unsigned long *)(fp_prev + offset_r14);
|
|
|
|
if (offset_r18)
|
|
*pprev_pc = *(unsigned long *)(fp_prev + offset_r18);
|
|
|
|
*pprev_pc &= ~1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Don't put this on the stack since we'll want to call sh64_unwind
|
|
* when we're close to underflowing the stack anyway. */
|
|
static struct pt_regs here_regs;
|
|
|
|
extern const char syscall_ret;
|
|
extern const char ret_from_syscall;
|
|
extern const char ret_from_exception;
|
|
extern const char ret_from_irq;
|
|
|
|
static void sh64_unwind_inner(struct pt_regs *regs);
|
|
|
|
static void unwind_nested (unsigned long pc, unsigned long fp)
|
|
{
|
|
if ((fp >= __MEMORY_START) &&
|
|
((fp & 7) == 0)) {
|
|
sh64_unwind_inner((struct pt_regs *) fp);
|
|
}
|
|
}
|
|
|
|
static void sh64_unwind_inner(struct pt_regs *regs)
|
|
{
|
|
unsigned long pc, fp;
|
|
int ofs = 0;
|
|
int first_pass;
|
|
|
|
pc = regs->pc & ~1;
|
|
fp = regs->regs[14];
|
|
|
|
first_pass = 1;
|
|
for (;;) {
|
|
int cond;
|
|
unsigned long next_fp, next_pc;
|
|
|
|
if (pc == ((unsigned long) &syscall_ret & ~1)) {
|
|
printk("SYSCALL\n");
|
|
unwind_nested(pc,fp);
|
|
return;
|
|
}
|
|
|
|
if (pc == ((unsigned long) &ret_from_syscall & ~1)) {
|
|
printk("SYSCALL (PREEMPTED)\n");
|
|
unwind_nested(pc,fp);
|
|
return;
|
|
}
|
|
|
|
/* In this case, the PC is discovered by lookup_prev_stack_frame but
|
|
it has 4 taken off it to look like the 'caller' */
|
|
if (pc == ((unsigned long) &ret_from_exception & ~1)) {
|
|
printk("EXCEPTION\n");
|
|
unwind_nested(pc,fp);
|
|
return;
|
|
}
|
|
|
|
if (pc == ((unsigned long) &ret_from_irq & ~1)) {
|
|
printk("IRQ\n");
|
|
unwind_nested(pc,fp);
|
|
return;
|
|
}
|
|
|
|
cond = ((pc >= __MEMORY_START) && (fp >= __MEMORY_START) &&
|
|
((pc & 3) == 0) && ((fp & 7) == 0));
|
|
|
|
pc -= ofs;
|
|
|
|
printk("[<%08lx>] ", pc);
|
|
print_symbol("%s\n", pc);
|
|
|
|
if (first_pass) {
|
|
/* If the innermost frame is a leaf function, it's
|
|
* possible that r18 is never saved out to the stack.
|
|
*/
|
|
next_pc = regs->regs[18];
|
|
} else {
|
|
next_pc = 0;
|
|
}
|
|
|
|
if (lookup_prev_stack_frame(fp, pc, &next_fp, &next_pc, regs) == 0) {
|
|
ofs = sizeof(unsigned long);
|
|
pc = next_pc & ~1;
|
|
fp = next_fp;
|
|
} else {
|
|
printk("Unable to lookup previous stack frame\n");
|
|
break;
|
|
}
|
|
first_pass = 0;
|
|
}
|
|
|
|
printk("\n");
|
|
|
|
}
|
|
|
|
void sh64_unwind(struct pt_regs *regs)
|
|
{
|
|
if (!regs) {
|
|
/*
|
|
* Fetch current regs if we have no other saved state to back
|
|
* trace from.
|
|
*/
|
|
regs = &here_regs;
|
|
|
|
__asm__ __volatile__ ("ori r14, 0, %0" : "=r" (regs->regs[14]));
|
|
__asm__ __volatile__ ("ori r15, 0, %0" : "=r" (regs->regs[15]));
|
|
__asm__ __volatile__ ("ori r18, 0, %0" : "=r" (regs->regs[18]));
|
|
|
|
__asm__ __volatile__ ("gettr tr0, %0" : "=r" (regs->tregs[0]));
|
|
__asm__ __volatile__ ("gettr tr1, %0" : "=r" (regs->tregs[1]));
|
|
__asm__ __volatile__ ("gettr tr2, %0" : "=r" (regs->tregs[2]));
|
|
__asm__ __volatile__ ("gettr tr3, %0" : "=r" (regs->tregs[3]));
|
|
__asm__ __volatile__ ("gettr tr4, %0" : "=r" (regs->tregs[4]));
|
|
__asm__ __volatile__ ("gettr tr5, %0" : "=r" (regs->tregs[5]));
|
|
__asm__ __volatile__ ("gettr tr6, %0" : "=r" (regs->tregs[6]));
|
|
__asm__ __volatile__ ("gettr tr7, %0" : "=r" (regs->tregs[7]));
|
|
|
|
__asm__ __volatile__ (
|
|
"pta 0f, tr0\n\t"
|
|
"blink tr0, %0\n\t"
|
|
"0: nop"
|
|
: "=r" (regs->pc)
|
|
);
|
|
}
|
|
|
|
printk("\nCall Trace:\n");
|
|
sh64_unwind_inner(regs);
|
|
}
|
|
|
|
|