Merge branch 'feature/backtrace_dumps' into 'master'

Feature/backtrace dumps

Github pull request https://github.com/espressif/esp-idf/pull/149

(Plus reformatting of panic.c, as it hadn't been formatted to our code style yet.)

See merge request !290

components/esp32/panic.c

@@ -45,48 +45,59 @@ 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);
 }
 
-inline static void panicPutStr(const char *c) {
+inline static void panicPutStr(const char *c)
+{
     int x = 0;
     while (c[x] != 0) {
-		panicPutchar(c[x]);
+        panicPutChar(c[x]);
         x++;
     }
 }
 
-inline static void panicPutHex(int a) {
+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;
     }
 }
 
-inline static void panicPutDec(int a) {
+inline static void panicPutDec(int a)
+{
     int n1, n2;
     n1 = a % 10;
     n2 = a / 10;
-	panicPutchar(' ');
+    if (n2 == 0) {
-	if (n2==0) panicPutchar(' '); else panicPutchar(n2+'0');
+        panicPutChar(' ');
-	panicPutchar(n1+'0');
+    } 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) { }
 #endif
 
 
-void  __attribute__((weak)) vApplicationStackOverflowHook( TaskHandle_t xTask, signed char *pcTaskName ) {
+void  __attribute__((weak)) vApplicationStackOverflowHook( TaskHandle_t xTask, signed char *pcTaskName )
+{
     panicPutStr("***ERROR*** A stack overflow in task ");
     panicPutStr((char *)pcTaskName);
     panicPutStr(" has been detected.\r\n");
@@ -117,7 +128,8 @@ static void haltOtherCore()
 }
 
 //Returns true when a debugger is attached using JTAG.
-static int inOCDMode() {
+static int inOCDMode()
+{
 #if CONFIG_ESP32_DEBUG_OCDAWARE
     int dcr;
     int reg = 0x10200C; //DSRSET register
@@ -128,7 +140,8 @@ static int inOCDMode() {
 #endif
 }
 
-void panicHandler(XtExcFrame *frame) {
+void panicHandler(XtExcFrame *frame)
+{
     int *regs = (int *)frame;
     //Please keep in sync with PANIC_RSN_* defines
     const char *reasons[] = {
@@ -142,7 +155,9 @@ void panicHandler(XtExcFrame *frame) {
     };
     const char *reason = reasons[0];
     //The panic reason is stored in the EXCCAUSE register.
-	if (regs[20]<=PANIC_RSN_MAX) reason=reasons[regs[20]];
+    if (regs[20] <= PANIC_RSN_MAX) {
+        reason = reasons[regs[20]];
+    }
     haltOtherCore();
     panicPutStr("Guru Meditation Error: Core ");
     panicPutDec(xPortGetCoreID());
@@ -156,7 +171,8 @@ void panicHandler(XtExcFrame *frame) {
     commonErrorHandler(frame);
 }
 
-static void setFirstBreakpoint(uint32_t pc) {
+static void setFirstBreakpoint(uint32_t pc)
+{
     asm(
         "wsr.ibreaka0 %0\n" \
         "rsr.ibreakenable a3\n" \
@@ -166,14 +182,19 @@ static void setFirstBreakpoint(uint32_t pc) {
         ::"r"(pc):"a3", "a4");
 }
 
-void xt_unhandled_exception(XtExcFrame *frame) {
+void xt_unhandled_exception(XtExcFrame *frame)
+{
     int *regs = (int *)frame;
     int x;
 
     haltOtherCore();
     panicPutStr("Guru Meditation Error of type ");
     x = regs[20];
-	if (x<40) panicPutStr(edesc[x]); else panicPutStr("Unknown");
+    if (x < 40) {
+        panicPutStr(edesc[x]);
+    } else {
+        panicPutStr("Unknown");
+    }
     panicPutStr(" occurred on core ");
     panicPutDec(xPortGetCoreID());
     if (inOCDMode()) {
@@ -197,7 +218,8 @@ the risk of somehow halting in the panic handler and not resetting. That is why
   all watchdogs except the timer group 0 watchdog, and it reconfigures that to reset the chip after
   one second.
 */
-static void reconfigureAllWdts() {
+static void reconfigureAllWdts()
+{
     TIMERG0.wdt_wprotect = TIMG_WDT_WKEY_VALUE;
     TIMERG0.wdt_feed = 1;
     TIMERG0.wdt_config0.sys_reset_length = 7;           //3.2uS
@@ -217,7 +239,8 @@ static void reconfigureAllWdts() {
 /*
   This disables all the watchdogs for when we call the gdbstub.
 */
-static void disableAllWdts() {
+static void disableAllWdts()
+{
     TIMERG0.wdt_wprotect = TIMG_WDT_WKEY_VALUE;
     TIMERG0.wdt_config0.en = 0;
     TIMERG0.wdt_wprotect = 0;
@@ -228,17 +251,55 @@ 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.
 */
-void commonErrorHandler(XtExcFrame *frame) {
+void commonErrorHandler(XtExcFrame *frame)
+{
     int *regs = (int *)frame;
     int x, y;
     const char *sdesc[] = {
         "PC      ", "PS      ", "A0      ", "A1      ", "A2      ", "A3      ", "A4      ", "A5      ",
         "A6      ", "A7      ", "A8      ", "A9      ", "A10     ", "A11     ", "A12     ", "A13     ",
-		"A14     ","A15     ","SAR     ","EXCCAUSE","EXCVADDR","LBEG    ","LEND    ","LCOUNT  "};
+        "A14     ", "A15     ", "SAR     ", "EXCCAUSE", "EXCVADDR", "LBEG    ", "LEND    ", "LCOUNT  "
+    };
 
     //Feed the watchdogs, so they will give us time to print out debug info
     reconfigureAllWdts();
@@ -249,20 +310,24 @@ 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");
     esp_gdbstub_panic_handler(frame);
 #elif CONFIG_ESP32_PANIC_PRINT_REBOOT || CONFIG_ESP32_PANIC_SILENT_REBOOT
     panicPutStr("Rebooting...\r\n");
-	for (x=0; x<100; x++) ets_delay_us(1000);
+    for (x = 0; x < 100; x++) {
+        ets_delay_us(1000);
+    }
     software_reset();
 #else
     disableAllWdts();
@@ -272,7 +337,10 @@ void commonErrorHandler(XtExcFrame *frame) {
 }
 
 
-void esp_set_breakpoint_if_jtag(void *fn) {
+void esp_set_breakpoint_if_jtag(void *fn)
-	if (!inOCDMode()) return;
+{
+    if (!inOCDMode()) {
+        return;
+    }
     setFirstBreakpoint((uint32_t)fn);
 }