mirror of
https://github.com/torvalds/linux.git
synced 2024-12-22 10:56:40 +00:00
eecac38b04
For lockdep support a reliable stack trace mechanism is needed. This patch adds support in OpenRISC for the stacktrace framework, implemented by a simple unwinder api. The unwinder api supports both framepointer and basic stack tracing. The unwinder is now used to replace the stack_dump() implementation as well. The new traces are inline with other architectures trace format: Call trace: [<c0004448>] show_stack+0x3c/0x58 [<c031c940>] dump_stack+0xa8/0xe4 [<c0008104>] __cpu_up+0x64/0x130 [<c000d268>] bringup_cpu+0x3c/0x178 [<c000d038>] cpuhp_invoke_callback+0xa8/0x1fc [<c000d680>] cpuhp_up_callbacks+0x44/0x14c [<c000e400>] cpu_up+0x14c/0x1bc [<c041da60>] smp_init+0x104/0x15c [<c033843c>] ? kernel_init+0x0/0x140 [<c0415e04>] kernel_init_freeable+0xbc/0x25c [<c033843c>] ? kernel_init+0x0/0x140 [<c0338458>] kernel_init+0x1c/0x140 [<c003a174>] ? schedule_tail+0x18/0xa0 [<c0006b80>] ret_from_fork+0x1c/0x9c Signed-off-by: Stafford Horne <shorne@gmail.com>
106 lines
2.8 KiB
C
106 lines
2.8 KiB
C
/*
|
|
* OpenRISC unwinder.c
|
|
*
|
|
* Reusable arch specific api for unwinding stacks.
|
|
*
|
|
* Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
|
|
*
|
|
* This file is licensed under the terms of the GNU General Public License
|
|
* version 2. This program is licensed "as is" without any warranty of any
|
|
* kind, whether express or implied.
|
|
*/
|
|
|
|
#include <linux/sched/task_stack.h>
|
|
#include <linux/kernel.h>
|
|
|
|
#include <asm/unwinder.h>
|
|
|
|
#ifdef CONFIG_FRAME_POINTER
|
|
struct or1k_frameinfo {
|
|
unsigned long *fp;
|
|
unsigned long ra;
|
|
unsigned long top;
|
|
};
|
|
|
|
/*
|
|
* Verify a frameinfo structure. The return address should be a valid text
|
|
* address. The frame pointer may be null if its the last frame, otherwise
|
|
* the frame pointer should point to a location in the stack after the the
|
|
* top of the next frame up.
|
|
*/
|
|
static inline int or1k_frameinfo_valid(struct or1k_frameinfo *frameinfo)
|
|
{
|
|
return (frameinfo->fp == NULL ||
|
|
(!kstack_end(frameinfo->fp) &&
|
|
frameinfo->fp > &frameinfo->top)) &&
|
|
__kernel_text_address(frameinfo->ra);
|
|
}
|
|
|
|
/*
|
|
* Create a stack trace doing scanning which is frame pointer aware. We can
|
|
* get reliable stack traces by matching the previously found frame
|
|
* pointer with the top of the stack address every time we find a valid
|
|
* or1k_frameinfo.
|
|
*
|
|
* Ideally the stack parameter will be passed as FP, but it can not be
|
|
* guaranteed. Therefore we scan each address looking for the first sign
|
|
* of a return address.
|
|
*
|
|
* The OpenRISC stack frame looks something like the following. The
|
|
* location SP is held in r1 and location FP is held in r2 when frame pointers
|
|
* enabled.
|
|
*
|
|
* SP -> (top of stack)
|
|
* - (callee saved registers)
|
|
* - (local variables)
|
|
* FP-8 -> previous FP \
|
|
* FP-4 -> return address |- or1k_frameinfo
|
|
* FP -> (previous top of stack) /
|
|
*/
|
|
void unwind_stack(void *data, unsigned long *stack,
|
|
void (*trace)(void *data, unsigned long addr, int reliable))
|
|
{
|
|
unsigned long *next_fp = NULL;
|
|
struct or1k_frameinfo *frameinfo = NULL;
|
|
int reliable = 0;
|
|
|
|
while (!kstack_end(stack)) {
|
|
frameinfo = container_of(stack,
|
|
struct or1k_frameinfo,
|
|
top);
|
|
|
|
if (__kernel_text_address(frameinfo->ra)) {
|
|
if (or1k_frameinfo_valid(frameinfo) &&
|
|
(next_fp == NULL ||
|
|
next_fp == &frameinfo->top)) {
|
|
reliable = 1;
|
|
next_fp = frameinfo->fp;
|
|
} else
|
|
reliable = 0;
|
|
|
|
trace(data, frameinfo->ra, reliable);
|
|
}
|
|
stack++;
|
|
}
|
|
}
|
|
|
|
#else /* CONFIG_FRAME_POINTER */
|
|
|
|
/*
|
|
* Create a stack trace by doing a simple scan treating all text addresses
|
|
* as return addresses.
|
|
*/
|
|
void unwind_stack(void *data, unsigned long *stack,
|
|
void (*trace)(void *data, unsigned long addr, int reliable))
|
|
{
|
|
unsigned long addr;
|
|
|
|
while (!kstack_end(stack)) {
|
|
addr = *stack++;
|
|
if (__kernel_text_address(addr))
|
|
trace(data, addr, 0);
|
|
}
|
|
}
|
|
#endif /* CONFIG_FRAME_POINTER */
|
|
|