* arch/arm/src/common/arm_backtrace_sp.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/arch.h>
#include "sched/sched.h"
#include "arm_internal.h"
* Pre-processor Definitions
****************************************************************************/
* To check an instruction, it is ANDed with the IMASK_ and
* the result is compared with the IOP_. The macro INSTR_IS
* does this and returns !0 to indicate a match.
*/
#define INSTR_IS(i, o) (((i) & (IMASK_##o)) == (IOP_##o))
#define IMASK_T_BLX 0xff80
#define IOP_T_BLX 0x4780
#define IMASK_T_BL 0xf800
#define IOP_T_BL 0xf000
* Private Data
****************************************************************************/
static void **g_backtrace_code_regions;
* Private Functions
****************************************************************************/
* Name: in_code_region
*
* Description:
* in_code_region() check if the program counter is in the program
* section, program counter should always be within the view of executable
* sections.
*
* Input Parameters:
* pc - Program counter address
*
* Returned Value:
* A boolean value: true the counter is valid
*
****************************************************************************/
nosanitize_address
static bool in_code_region(unsigned long pc)
{
int i = 0;
if (g_backtrace_code_regions)
{
while (g_backtrace_code_regions[i] &&
(g_backtrace_code_regions[i] !=
g_backtrace_code_regions[i + 1]))
{
if (g_backtrace_code_regions[i] <= (void *)pc &&
g_backtrace_code_regions[i + 1] > (void *)pc)
{
return true;
}
i += 2;
}
}
else if (pc >= (unsigned long)_START_TEXT && pc < (unsigned long)_END_TEXT)
{
return true;
}
return false;
}
* Name: backtrace_branch
*
* Description:
* backtrace() parsing the return address through branch instruction
*
****************************************************************************/
nosanitize_address
static int backtrace_branch(unsigned long top, unsigned long sp,
void **buffer, int size, int *skip)
{
unsigned long addr;
uint16_t ins16;
int i;
irqstate_t flags;
flags = enter_critical_section();
for (i = 0; i < size && sp < top; sp += sizeof(unsigned long))
{
addr = *(unsigned long *)sp;
if (!in_code_region(addr))
{
continue;
}
addr = (addr & ~1) - 2;
if (!in_code_region(addr))
{
continue;
}
ins16 = *(uint16_t *)addr;
if (INSTR_IS(ins16, T_BLX))
{
if ((*skip)-- <= 0)
{
buffer[i++] = (void *)addr;
}
}
* OFFSET: 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
* VALUE : 1 1 1 1 0 - - - - - - - - - - -
* OFFSET: 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
* VALUE : 1 1 - 1 - - - - - - - - - - - -
*/
else if ((ins16 & 0xd000) == 0xd000)
{
addr -= 2;
if (!in_code_region(addr))
{
continue;
}
ins16 = *(uint16_t *)addr;
if (INSTR_IS(ins16, T_BL))
{
if ((*skip)-- <= 0)
{
buffer[i++] = (void *)addr;
}
}
}
}
leave_critical_section(flags);
return i;
}
* Public Functions
****************************************************************************/
* Name: up_backtrace_init_code_regions
*
* Description:
* The up call up_backtrace_init_code_regions() will set the start
* and end addresses of the customized program sections, this method
* will help the different boards to configure the current text
* sections for some complicate platforms
*
* Input Parameters:
* regions The start and end address of the text segment
* This interface supports the input of multiple
* groups of sections, Each set of the sections
* must be a pair, the end of the area must specify
* two NULL porint, e.g :
*
* static void *g_code_regions[] =
* {
* _START_TEXT, _END_TEXT,
* _START2_TEXT, _END2_TEXT,
* _START3_TEXT, _END3_TEXT,
* NULL, NULL,
* };
*
* up_backtrace_init_code_regions(g_code_regions);
*
****************************************************************************/
nosanitize_address
void up_backtrace_init_code_regions(void **regions)
{
g_backtrace_code_regions = regions;
}
* Name: up_backtrace
*
* Description:
* up_backtrace() returns a backtrace for the TCB, in the array
* pointed to by buffer. A backtrace is the series of currently active
* function calls for the program. Each item in the array pointed to by
* buffer is of type void *, and is the return address from the
* corresponding stack frame. The size argument specifies the maximum
* number of addresses that can be stored in buffer. If the backtrace is
* larger than size, then the addresses corresponding to the size most
* recent function calls are returned; to obtain the complete backtrace,
* make sure that buffer and size are large enough.
*
* Input Parameters:
* tcb - Address of the task's TCB
* buffer - Return address from the corresponding stack frame
* size - Maximum number of addresses that can be stored in buffer
*
* Returned Value:
* up_backtrace() returns the number of addresses returned in buffer
*
* Assumptions:
* Have to make sure tcb keep safe during function executing, it means
* 1. Tcb have to be self or not-running. In SMP case, the running task
* PC & SP cannot be backtrace, as whose get from tcb is not the newest.
* 2. Tcb have to keep not be freed. In task exiting case, have to
* make sure the tcb get from pid and up_backtrace in one critical
* section procedure.
*
****************************************************************************/
nosanitize_address
int up_backtrace(struct tcb_s *tcb,
void **buffer, int size, int skip)
{
struct tcb_s *rtcb = running_task();
unsigned long sp;
int ret;
if (size <= 0 || !buffer)
{
return 0;
}
if (tcb == NULL)
{
tcb = rtcb;
}
if (tcb == rtcb)
{
sp = up_getsp();
if (up_interrupt_context())
{
unsigned long top =
#if CONFIG_ARCH_INTERRUPTSTACK > 7
up_get_intstackbase(this_cpu()) + INTSTACK_SIZE;
#else
(unsigned long)rtcb->stack_base_ptr +
rtcb->adj_stack_size;
#endif
ret = backtrace_branch(top, sp, buffer, size, &skip);
if (ret < size)
{
ret += backtrace_branch((unsigned long)
rtcb->stack_base_ptr +
rtcb->adj_stack_size,
((uint32_t *)running_regs())[REG_SP],
&buffer[ret],
size - ret, &skip);
}
}
else
{
ret = backtrace_branch((unsigned long)
rtcb->stack_base_ptr +
rtcb->adj_stack_size, sp,
buffer, size, &skip);
}
}
else
{
ret = 0;
if (tcb->xcp.regs[REG_PC] && skip-- <= 0)
{
buffer[ret++] = (void *)tcb->xcp.regs[REG_PC];
}
sp = tcb->xcp.regs[REG_SP];
ret += backtrace_branch((unsigned long)
tcb->stack_base_ptr +
tcb->adj_stack_size, sp,
&buffer[ret], size - ret, &skip);
}
return ret;
}