cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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stacktrace.c (2112B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2#include <linux/sched.h>
      3#include <linux/sched/debug.h>
      4#include <linux/stacktrace.h>
      5#include <linux/thread_info.h>
      6#include <linux/ftrace.h>
      7#include <linux/export.h>
      8#include <asm/ptrace.h>
      9#include <asm/stacktrace.h>
     10
     11#include "kstack.h"
     12
     13static void __save_stack_trace(struct thread_info *tp,
     14			       struct stack_trace *trace,
     15			       bool skip_sched)
     16{
     17	unsigned long ksp, fp;
     18#ifdef CONFIG_FUNCTION_GRAPH_TRACER
     19	struct task_struct *t;
     20	int graph = 0;
     21#endif
     22
     23	if (tp == current_thread_info()) {
     24		stack_trace_flush();
     25		__asm__ __volatile__("mov %%fp, %0" : "=r" (ksp));
     26	} else {
     27		ksp = tp->ksp;
     28	}
     29
     30	fp = ksp + STACK_BIAS;
     31#ifdef CONFIG_FUNCTION_GRAPH_TRACER
     32	t = tp->task;
     33#endif
     34	do {
     35		struct sparc_stackf *sf;
     36		struct pt_regs *regs;
     37		unsigned long pc;
     38
     39		if (!kstack_valid(tp, fp))
     40			break;
     41
     42		sf = (struct sparc_stackf *) fp;
     43		regs = (struct pt_regs *) (sf + 1);
     44
     45		if (kstack_is_trap_frame(tp, regs)) {
     46			if (!(regs->tstate & TSTATE_PRIV))
     47				break;
     48			pc = regs->tpc;
     49			fp = regs->u_regs[UREG_I6] + STACK_BIAS;
     50		} else {
     51			pc = sf->callers_pc;
     52			fp = (unsigned long)sf->fp + STACK_BIAS;
     53		}
     54
     55		if (trace->skip > 0)
     56			trace->skip--;
     57		else if (!skip_sched || !in_sched_functions(pc)) {
     58			trace->entries[trace->nr_entries++] = pc;
     59#ifdef CONFIG_FUNCTION_GRAPH_TRACER
     60			if ((pc + 8UL) == (unsigned long) &return_to_handler) {
     61				struct ftrace_ret_stack *ret_stack;
     62				ret_stack = ftrace_graph_get_ret_stack(t,
     63								       graph);
     64				if (ret_stack) {
     65					pc = ret_stack->ret;
     66					if (trace->nr_entries <
     67					    trace->max_entries)
     68						trace->entries[trace->nr_entries++] = pc;
     69					graph++;
     70				}
     71			}
     72#endif
     73		}
     74	} while (trace->nr_entries < trace->max_entries);
     75}
     76
     77void save_stack_trace(struct stack_trace *trace)
     78{
     79	__save_stack_trace(current_thread_info(), trace, false);
     80}
     81EXPORT_SYMBOL_GPL(save_stack_trace);
     82
     83void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
     84{
     85	struct thread_info *tp = task_thread_info(tsk);
     86
     87	__save_stack_trace(tp, trace, true);
     88}
     89EXPORT_SYMBOL_GPL(save_stack_trace_tsk);