/* This is called from KBacktraceIterator_init_current() */
void _KBacktraceIterator_init_current(struct KBacktraceIterator *kbt, ulong pc,
ulong lr, ulong sp, ulong r52)
{
struct pt_regs regs;
KBacktraceIterator_init(kbt, NULL,
regs_to_pt_regs(®s, pc, lr, sp, r52));
}
/* This is called only from kernel/sched.c, with esp == NULL */
void show_stack(struct task_struct *task, unsigned long *esp)
{
struct KBacktraceIterator kbt;
if (task == NULL || task == current)
KBacktraceIterator_init_current(&kbt);
else
KBacktraceIterator_init(&kbt, task, NULL);
tile_show_stack(&kbt, 0);
}
void tile_backtrace(struct pt_regs *const regs, unsigned int depth)
{
struct KBacktraceIterator kbt;
unsigned int i;
/*
* Get the address just after the "jalr" instruction that
* jumps to the handler for a syscall. When we find this
* address in a backtrace, we silently ignore it, which gives
* us a one-step backtrace connection from the sys_xxx()
* function in the kernel to the xxx() function in libc.
* Otherwise, we lose the ability to properly attribute time
* from the libc calls to the kernel implementations, since
* oprofile only considers PCs from backtraces a pair at a time.
*/
unsigned long handle_syscall_pc = handle_syscall_link_address();
KBacktraceIterator_init(&kbt, NULL, regs);
kbt.profile = 1;
/*
* The sample for the pc is already recorded. Now we are adding the
* address of the callsites on the stack. Our iterator starts
* with the frame of the (already sampled) call site. If our
* iterator contained a "return address" field, we could have just
* used it and wouldn't have needed to skip the first
* frame. That's in effect what the arm and x86 versions do.
* Instead we peel off the first iteration to get the equivalent
* behavior.
*/
if (KBacktraceIterator_end(&kbt))
return;
KBacktraceIterator_next(&kbt);
for (i = 0; i < depth; ++i) {
int is_kernel;
unsigned long pc;
if (KBacktraceIterator_end(&kbt))
break;
pc = kbt.it.pc;
is_kernel = (pc >= PAGE_OFFSET &&
!is_arch_mappable_range(pc, 1));
if (pc != handle_syscall_pc)
oprofile_add_pc(pc, is_kernel, 0);
KBacktraceIterator_next(&kbt);
}
}
void save_stack_trace_tsk(struct task_struct *task, struct stack_trace *trace)
{
struct KBacktraceIterator kbt;
int skip = trace->skip;
int i = 0;
if (task == NULL || task == current)
KBacktraceIterator_init_current(&kbt);
else
KBacktraceIterator_init(&kbt, task, NULL);
for (; !KBacktraceIterator_end(&kbt); KBacktraceIterator_next(&kbt)) {
if (skip) {
--skip;
continue;
}
if (i >= trace->max_entries || kbt.it.pc < PAGE_OFFSET)
break;
trace->entries[i++] = kbt.it.pc;
}
trace->nr_entries = i;
}
/* This is called from show_regs() and _dump_stack() */
void dump_stack_regs(struct pt_regs *regs)
{
struct KBacktraceIterator kbt;
KBacktraceIterator_init(&kbt, NULL, regs);
tile_show_stack(&kbt, 1);
}
