From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/arch/arm64/kernel/stacktrace.c | 208 +++++++++++++++++++++++++++++----------------------
1 files changed, 117 insertions(+), 91 deletions(-)
diff --git a/kernel/arch/arm64/kernel/stacktrace.c b/kernel/arch/arm64/kernel/stacktrace.c
index bb482ec..a336782 100644
--- a/kernel/arch/arm64/kernel/stacktrace.c
+++ b/kernel/arch/arm64/kernel/stacktrace.c
@@ -1,19 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Stack tracing support
*
* Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/kernel.h>
#include <linux/export.h>
@@ -25,6 +14,7 @@
#include <linux/stacktrace.h>
#include <asm/irq.h>
+#include <asm/pointer_auth.h>
#include <asm/stack_pointer.h>
#include <asm/stacktrace.h>
@@ -41,9 +31,18 @@
* ldp x29, x30, [sp]
* add sp, sp, #0x10
*/
+
+/*
+ * Unwind from one frame record (A) to the next frame record (B).
+ *
+ * We terminate early if the location of B indicates a malformed chain of frame
+ * records (e.g. a cycle), determined based on the location and fp value of A
+ * and the location (but not the fp value) of B.
+ */
int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
{
unsigned long fp = frame->fp;
+ struct stack_info info;
if (fp & 0xf)
return -EINVAL;
@@ -51,29 +50,59 @@
if (!tsk)
tsk = current;
- if (!on_accessible_stack(tsk, fp, NULL))
+ if (!on_accessible_stack(tsk, fp, &info))
return -EINVAL;
+ if (test_bit(info.type, frame->stacks_done))
+ return -EINVAL;
+
+ /*
+ * As stacks grow downward, any valid record on the same stack must be
+ * at a strictly higher address than the prior record.
+ *
+ * Stacks can nest in several valid orders, e.g.
+ *
+ * TASK -> IRQ -> OVERFLOW -> SDEI_NORMAL
+ * TASK -> SDEI_NORMAL -> SDEI_CRITICAL -> OVERFLOW
+ *
+ * ... but the nesting itself is strict. Once we transition from one
+ * stack to another, it's never valid to unwind back to that first
+ * stack.
+ */
+ if (info.type == frame->prev_type) {
+ if (fp <= frame->prev_fp)
+ return -EINVAL;
+ } else {
+ set_bit(frame->prev_type, frame->stacks_done);
+ }
+
+ /*
+ * Record this frame record's values and location. The prev_fp and
+ * prev_type are only meaningful to the next unwind_frame() invocation.
+ */
frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp));
frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8));
+ frame->prev_fp = fp;
+ frame->prev_type = info.type;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if (tsk->ret_stack &&
- (frame->pc == (unsigned long)return_to_handler)) {
- if (WARN_ON_ONCE(frame->graph == -1))
- return -EINVAL;
- if (frame->graph < -1)
- frame->graph += FTRACE_NOTRACE_DEPTH;
-
+ (ptrauth_strip_insn_pac(frame->pc) == (unsigned long)return_to_handler)) {
+ struct ftrace_ret_stack *ret_stack;
/*
* This is a case where function graph tracer has
* modified a return address (LR) in a stack frame
* to hook a function return.
* So replace it to an original value.
*/
- frame->pc = tsk->ret_stack[frame->graph--].ret;
+ ret_stack = ftrace_graph_get_ret_stack(tsk, frame->graph++);
+ if (WARN_ON_ONCE(!ret_stack))
+ return -EINVAL;
+ frame->pc = ret_stack->ret;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+ frame->pc = ptrauth_strip_insn_pac(frame->pc);
/*
* Frames created upon entry from EL0 have NULL FP and PC values, so
@@ -89,12 +118,12 @@
NOKPROBE_SYMBOL(unwind_frame);
void notrace walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
- int (*fn)(struct stackframe *, void *), void *data)
+ bool (*fn)(void *, unsigned long), void *data)
{
while (1) {
int ret;
- if (fn(frame, data))
+ if (!fn(data, frame->pc))
break;
ret = unwind_frame(tsk, frame);
if (ret < 0)
@@ -103,94 +132,91 @@
}
NOKPROBE_SYMBOL(walk_stackframe);
-#ifdef CONFIG_STACKTRACE
-struct stack_trace_data {
- struct stack_trace *trace;
- unsigned int no_sched_functions;
- unsigned int skip;
-};
-
-static int save_trace(struct stackframe *frame, void *d)
+static void dump_backtrace_entry(unsigned long where, const char *loglvl)
{
- struct stack_trace_data *data = d;
- struct stack_trace *trace = data->trace;
- unsigned long addr = frame->pc;
+ printk("%s %pS\n", loglvl, (void *)where);
+}
- if (data->no_sched_functions && in_sched_functions(addr))
- return 0;
- if (data->skip) {
- data->skip--;
- return 0;
+void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
+ const char *loglvl)
+{
+ struct stackframe frame;
+ int skip = 0;
+
+ pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
+
+ if (regs) {
+ if (user_mode(regs))
+ return;
+ skip = 1;
}
- trace->entries[trace->nr_entries++] = addr;
-
- return trace->nr_entries >= trace->max_entries;
-}
-
-void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
-{
- struct stack_trace_data data;
- struct stackframe frame;
-
- data.trace = trace;
- data.skip = trace->skip;
- data.no_sched_functions = 0;
-
- frame.fp = regs->regs[29];
- frame.pc = regs->pc;
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- frame.graph = current->curr_ret_stack;
-#endif
-
- walk_stackframe(current, &frame, save_trace, &data);
- if (trace->nr_entries < trace->max_entries)
- trace->entries[trace->nr_entries++] = ULONG_MAX;
-}
-
-static noinline void __save_stack_trace(struct task_struct *tsk,
- struct stack_trace *trace, unsigned int nosched)
-{
- struct stack_trace_data data;
- struct stackframe frame;
+ if (!tsk)
+ tsk = current;
if (!try_get_task_stack(tsk))
return;
- data.trace = trace;
- data.skip = trace->skip;
- data.no_sched_functions = nosched;
-
- if (tsk != current) {
- frame.fp = thread_saved_fp(tsk);
- frame.pc = thread_saved_pc(tsk);
+ if (tsk == current) {
+ start_backtrace(&frame,
+ (unsigned long)__builtin_frame_address(0),
+ (unsigned long)dump_backtrace);
} else {
- /* We don't want this function nor the caller */
- data.skip += 2;
- frame.fp = (unsigned long)__builtin_frame_address(0);
- frame.pc = (unsigned long)__save_stack_trace;
+ /*
+ * task blocked in __switch_to
+ */
+ start_backtrace(&frame,
+ thread_saved_fp(tsk),
+ thread_saved_pc(tsk));
}
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- frame.graph = tsk->curr_ret_stack;
-#endif
- walk_stackframe(tsk, &frame, save_trace, &data);
- if (trace->nr_entries < trace->max_entries)
- trace->entries[trace->nr_entries++] = ULONG_MAX;
+ printk("%sCall trace:\n", loglvl);
+ do {
+ /* skip until specified stack frame */
+ if (!skip) {
+ dump_backtrace_entry(frame.pc, loglvl);
+ } else if (frame.fp == regs->regs[29]) {
+ skip = 0;
+ /*
+ * Mostly, this is the case where this function is
+ * called in panic/abort. As exception handler's
+ * stack frame does not contain the corresponding pc
+ * at which an exception has taken place, use regs->pc
+ * instead.
+ */
+ dump_backtrace_entry(regs->pc, loglvl);
+ }
+ } while (!unwind_frame(tsk, &frame));
put_task_stack(tsk);
}
-EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+EXPORT_SYMBOL_GPL(dump_backtrace);
-void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+void show_stack(struct task_struct *tsk, unsigned long *sp, const char *loglvl)
{
- __save_stack_trace(tsk, trace, 1);
+ dump_backtrace(NULL, tsk, loglvl);
+ barrier();
}
-void save_stack_trace(struct stack_trace *trace)
+#ifdef CONFIG_STACKTRACE
+
+noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry,
+ void *cookie, struct task_struct *task,
+ struct pt_regs *regs)
{
- __save_stack_trace(current, trace, 0);
+ struct stackframe frame;
+
+ if (regs)
+ start_backtrace(&frame, regs->regs[29], regs->pc);
+ else if (task == current)
+ start_backtrace(&frame,
+ (unsigned long)__builtin_frame_address(1),
+ (unsigned long)__builtin_return_address(0));
+ else
+ start_backtrace(&frame, thread_saved_fp(task),
+ thread_saved_pc(task));
+
+ walk_stackframe(task, &frame, consume_entry, cookie);
}
-EXPORT_SYMBOL_GPL(save_stack_trace);
#endif
--
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