9 May
2019
9 May
'19
9:27 a.m.
On Thu, May 09, 2019 at 10:14:31AM +0200, Peter Zijlstra wrote:
struct ftrace_regs_stack { ftrace_func_t func; unsigned long parent_ip; };
void ftrace_regs_handler(struct pr_regs *regs) { struct ftrace_regs_stack *st = (void *)regs->sp; ftrace_func_t func = st->func;
regs->sp += sizeof(long); /* pop func */
func(regs->ip, st->parent_ip, function_trace_op, regs); }
Alternatively we can add things like:
static inline unsigned long int3_emulate_pop(struct pt_regs *regs) { unsigned long val = *(unsigned long *)regs->sp; regs->sp += sizeof(unsigned long); return val; }
And do:
ftrace_func_t func = (void *)int3_emulate_pop(regs);