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Adjust error paths locking and returning 

Various fixes in preparation for making sure error calls do not return.

* Clear out handle_error's use of error_in_progress as a sort of spin
  lock; this is most likely to deadlock if ever activated, and conflicts
  with error's use of error_in_progress. Use a normal critical section lock.

* Make error use same mbed_halt_system helper as mbed_error.

* Make error's recursion check avoid print and proceed to halt, rather
  than returning.

* Make mbed_error use error_in_progress to avoid recursion in same way
  as error() does.

* Give mbed_halt_system its own recursion check in case of error in
  mbed_die - give it a simple fallback.

* Make the in_progress things properly atomic, just in case.
pull/8328/head
Kevin Bracey 2018-10-05 16:43:41 +03:00
parent c32984c3a8
commit 57748bd46e
1 changed files with 41 additions and 40 deletions
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81
platform/mbed_error.c
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@ -36,7 +36,8 @@ static void print_error_report(const mbed_error_ctx *ctx, const char *, const ch
#define ERROR_REPORT(ctx, error_msg, error_filename, error_line) ((void) 0)
#endif
static uint8_t error_in_progress = 0;
static core_util_atomic_flag error_in_progress = CORE_UTIL_ATOMIC_FLAG_INIT;
static core_util_atomic_flag halt_in_progress = CORE_UTIL_ATOMIC_FLAG_INIT;
static int error_count = 0;
static mbed_error_ctx first_error_ctx = {0};
static mbed_error_ctx last_error_ctx = {0};
@ -46,37 +47,41 @@ static mbed_error_status_t handle_error(mbed_error_status_t error_status, unsign
//Helper function to halt the system
static void mbed_halt_system(void)
{
//If not in ISR context exit, otherwise spin on WFI
if (core_util_is_isr_active() || !core_util_are_interrupts_enabled()) {
// Prevent recursion if halt is called again during halt attempt - try
// something simple instead.
if (core_util_atomic_flag_test_and_set(&halt_in_progress)) {
core_util_critical_section_enter();
__DSB();
for (;;) {
__WFI();
__WFE(); // Not WFI, as don't want to wake for pending interrupts
}
} else {
//exit eventually calls mbed_die
exit(1);
}
//If in ISR context, call mbed_die directly
if (core_util_is_isr_active() || !core_util_are_interrupts_enabled()) {
mbed_die();
}
// In normal context, try orderly exit(1), which eventually calls mbed_die
exit(1);
}
WEAK void error(const char *format, ...)
{
// Prevent recursion if error is called again
if (error_in_progress) {
return;
}
//Call handle_error/print_error_report permanently setting error_in_progress flag
handle_error(MBED_ERROR_UNKNOWN, 0, NULL, 0, MBED_CALLER_ADDR());
ERROR_REPORT(&last_error_ctx, "Fatal Run-time error", NULL, 0);
error_in_progress = 1;
// Prevent recursion if error is called again during store+print attempt
if (!core_util_atomic_flag_test_and_set(&error_in_progress)) {
handle_error(MBED_ERROR_UNKNOWN, 0, NULL, 0, MBED_CALLER_ADDR());
ERROR_REPORT(&last_error_ctx, "Fatal Run-time error", NULL, 0);
#ifndef NDEBUG
va_list arg;
va_start(arg, format);
mbed_error_vprintf(format, arg);
va_end(arg);
va_list arg;
va_start(arg, format);
mbed_error_vprintf(format, arg);
va_end(arg);
#endif
exit(1);
}
mbed_halt_system();
}
//Set an error status with the error handling system
@ -91,18 +96,6 @@ static mbed_error_status_t handle_error(mbed_error_status_t error_status, unsign
error_status = MBED_ERROR_INVALID_ARGUMENT;
}
//Prevent corruption by holding out other callers
//and we also need this until we remove the "error" call completely
while (error_in_progress == 1);
//Use critsect here, as we don't want inadvertant modification of this global variable
core_util_critical_section_enter();
error_in_progress = 1;
core_util_critical_section_exit();
//Increment error count
error_count++;
//Clear the context capturing buffer
memset(&current_error_ctx, 0, sizeof(mbed_error_ctx));
//Capture error information
@ -126,6 +119,12 @@ static mbed_error_status_t handle_error(mbed_error_status_t error_status, unsign
current_error_ctx.error_line_number = line_number;
#endif
//Prevent corruption by holding out other callers
core_util_critical_section_enter();
//Increment error count
error_count++;
//Capture the fist system error and store it
if (error_count == 1) { //first error
memcpy(&first_error_ctx, &current_error_ctx, sizeof(mbed_error_ctx));
@ -144,7 +143,7 @@ static mbed_error_status_t handle_error(mbed_error_status_t error_status, unsign
error_hook(&last_error_ctx);
}
error_in_progress = 0;
core_util_critical_section_exit();
return MBED_SUCCESS;
}
@ -179,13 +178,15 @@ mbed_error_status_t mbed_warning(mbed_error_status_t error_status, const char *e
//Sets a fatal error, this function is marked WEAK to be able to override this for some tests
WEAK mbed_error_status_t mbed_error(mbed_error_status_t error_status, const char *error_msg, unsigned int error_value, const char *filename, int line_number)
{
//set the error reported and then halt the system
if (MBED_SUCCESS != handle_error(error_status, error_value, filename, line_number, MBED_CALLER_ADDR())) {
return MBED_ERROR_FAILED_OPERATION;
// Prevent recursion if error is called again during store+print attempt
if (!core_util_atomic_flag_test_and_set(&error_in_progress)) {
//set the error reported
(void) handle_error(error_status, error_value, filename, line_number, MBED_CALLER_ADDR());
//On fatal errors print the error context/report
ERROR_REPORT(&last_error_ctx, error_msg, filename, line_number);
}
//On fatal errors print the error context/report
ERROR_REPORT(&last_error_ctx, error_msg, filename, line_number);
mbed_halt_system();
return MBED_ERROR_FAILED_OPERATION;