Crash_Override/OVMS3-idf
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Add backtrace to exception output.

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On Xtensa windowed ABI backtrace is easy to do, and it's immensely
useful for debugging, so - do it by default.
We try to be careful and not deref bogus pointers while walking the
frames.

Example output (from debugging espressif/esp-idf#133):

Backtrace: 0x1:0x3ffc51e0 0x400e9dfa:0x3ffc5210 0x400e9ebc:0x3ffc5230 0x400ec487:0x3ffc5260

With just addr2line utility from binutils, this already pinpoints the
location of the crash.
This commit is contained in:
Deomid Ryabkov 2016-12-07 18:58:55 +00:00
parent 6dc77bc55c
commit 20fd57f147
1 changed files with 36 additions and 9 deletions
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45
components/esp32/panic.c
View file

@ -45,7 +45,7 @@ Note: The linker script will put everything in this file in IRAM/DRAM, so it als
#if !CONFIG_ESP32_PANIC_SILENT_REBOOT
//printf may be broken, so we fix our own printing fns...
inline static void panicPutchar(char c) {
inline static void panicPutChar(char c) {
while (((READ_PERI_REG(UART_STATUS_REG(0))>>UART_TXFIFO_CNT_S)&UART_TXFIFO_CNT)>=126) ;
WRITE_PERI_REG(UART_FIFO_REG(0), c);
}
@ -53,7 +53,7 @@ inline static void panicPutchar(char c) {
inline static void panicPutStr(const char *c) {
int x=0;
while (c[x]!=0) {
panicPutchar(c[x]);
panicPutChar(c[x]);
x++;
}
}
@ -61,10 +61,9 @@ inline static void panicPutStr(const char *c) {
inline static void panicPutHex(int a) {
int x;
int c;
panicPutchar(' ');
for (x=0; x<8; x++) {
c=(a>>28)&0xf;
if (c<10) panicPutchar('0'+c); else panicPutchar('a'+c-10);
if (c<10) panicPutChar('0'+c); else panicPutChar('a'+c-10);
a<<=4;
}
}
@ -73,13 +72,12 @@ inline static void panicPutDec(int a) {
int n1, n2;
n1=a%10;
n2=a/10;
panicPutchar(' ');
if (n2==0) panicPutchar(' '); else panicPutchar(n2+'0');
panicPutchar(n1+'0');
if (n2==0) panicPutChar(' '); else panicPutChar(n2+'0');
panicPutChar(n1+'0');
}
#else
//No printing wanted. Stub out these functions.
inline static void panicPutchar(char c) { }
inline static void panicPutChar(char c) { }
inline static void panicPutStr(const char *c) { }
inline static void panicPutHex(int a) { }
inline static void panicPutDec(int a) { }
@ -228,6 +226,33 @@ static void disableAllWdts() {
#endif
static inline bool stackPointerIsSane(uint32_t sp) {
return !(sp < 0x3ffae010 || sp > 0x3ffffff0 || ((sp & 0xf) != 0));
}
static void putEntry(uint32_t pc, uint32_t sp) {
if (pc & 0x80000000) pc = (pc & 0x3fffffff) | 0x40000000;
panicPutStr(" 0x");
panicPutHex(pc);
panicPutStr(":0x");
panicPutHex(sp);
}
void doBacktrace(XtExcFrame *frame) {
uint32_t i = 0, pc = frame->pc, sp = frame->a1;
panicPutStr("\nBacktrace:");
/* Do not check sanity on first entry, PC could be smashed. */
putEntry(pc, sp);
pc = frame->a0;
while (i++ < 100) {
uint32_t psp = sp;
if (!stackPointerIsSane(sp) || i++ > 100) break;
sp = *((uint32_t *) (sp - 0x10 + 4));
putEntry(pc, sp);
pc = *((uint32_t *) (psp - 0x10));
if (pc < 0x40000000) break;
}
panicPutStr("\n\n");
}
/*
We arrive here after a panic or unhandled exception, when no OCD is detected. Dump the registers to the
serial port and either jump to the gdb stub, halt the CPU or reboot.
@ -249,13 +274,15 @@ void commonErrorHandler(XtExcFrame *frame) {
for (y=0; y<4; y++) {
if (sdesc[x+y][0]!=0) {
panicPutStr(sdesc[x+y]);
panicPutStr(": ");
panicPutStr(": 0x");
panicPutHex(regs[x+y+1]);
panicPutStr(" ");
}
}
panicPutStr("\r\n");
}
/* With windowed ABI backtracing is easy, let's do it. */
doBacktrace(frame);
#if CONFIG_ESP32_PANIC_GDBSTUB
disableAllWdts();
panicPutStr("Entering gdb stub now.\r\n");