subtree bump: libethash

libethash/internal.c

@@ -364,6 +364,7 @@ static bool ethash_mmap(struct ethash_full* ret, FILE* f)
 {
 	int fd;
 	char* mmapped_data;
+	errno = 0;
 	ret->file = f;
 	if ((fd = ethash_fileno(ret->file)) == -1) {
 		return false;
@@ -400,38 +401,48 @@ ethash_full_t ethash_full_new_internal(
 	ret->file_size = (size_t)full_size;
 	switch (ethash_io_prepare(dirname, seed_hash, &f, (size_t)full_size, false)) {
 	case ETHASH_IO_FAIL:
+		// ethash_io_prepare will do all ETHASH_CRITICAL() logging in fail case
 		goto fail_free_full;
 	case ETHASH_IO_MEMO_MATCH:
 		if (!ethash_mmap(ret, f)) {
+			ETHASH_CRITICAL("mmap failure()");
 			goto fail_close_file;
 		}
 		return ret;
 	case ETHASH_IO_MEMO_SIZE_MISMATCH:
 		// if a DAG of same filename but unexpected size is found, silently force new file creation
 		if (ethash_io_prepare(dirname, seed_hash, &f, (size_t)full_size, true) != ETHASH_IO_MEMO_MISMATCH) {
+			ETHASH_CRITICAL("Could not recreate DAG file after finding existing DAG with unexpected size.");
 			goto fail_free_full;
 		}
 		// fallthrough to the mismatch case here, DO NOT go through match
 	case ETHASH_IO_MEMO_MISMATCH:
 		if (!ethash_mmap(ret, f)) {
+			ETHASH_CRITICAL("mmap failure()");
 			goto fail_close_file;
 		}
 		break;
 	}
 
 	if (!ethash_compute_full_data(ret->data, full_size, light, callback)) {
+		ETHASH_CRITICAL("Failure at computing DAG data.");
 		goto fail_free_full_data;
 	}
 
 	// after the DAG has been filled then we finalize it by writting the magic number at the beginning
 	if (fseek(f, 0, SEEK_SET) != 0) {
+		ETHASH_CRITICAL("Could not seek to DAG file start to write magic number.");
 		goto fail_free_full_data;
 	}
 	uint64_t const magic_num = ETHASH_DAG_MAGIC_NUM;
 	if (fwrite(&magic_num, ETHASH_DAG_MAGIC_NUM_SIZE, 1, f) != 1) {
+		ETHASH_CRITICAL("Could not write magic number to DAG's beginning.");
+		goto fail_free_full_data;
+	}
+	if (fflush(f) != 0) {// make sure the magic number IS there
+		ETHASH_CRITICAL("Could not flush memory mapped data to DAG file. Insufficient space?");
 		goto fail_free_full_data;
 	}
-	fflush(f); // make sure the magic number IS there
 	return ret;
 
 fail_free_full_data:

libethash/io.c

@@ -21,6 +21,7 @@
 #include "io.h"
 #include <string.h>
 #include <stdio.h>
+#include <errno.h>
 
 enum ethash_io_rc ethash_io_prepare(
 	char const* dirname,
@@ -32,15 +33,19 @@ enum ethash_io_rc ethash_io_prepare(
 {
 	char mutable_name[DAG_MUTABLE_NAME_MAX_SIZE];
 	enum ethash_io_rc ret = ETHASH_IO_FAIL;
+	// reset errno before io calls
+	errno = 0;
 
 	// assert directory exists
 	if (!ethash_mkdir(dirname)) {
+		ETHASH_CRITICAL("Could not create the ethash directory");
 		goto end;
 	}
 
 	ethash_io_mutable_name(ETHASH_REVISION, &seedhash, mutable_name);
 	char* tmpfile = ethash_io_create_filename(dirname, mutable_name, strlen(mutable_name));
 	if (!tmpfile) {
+		ETHASH_CRITICAL("Could not create the full DAG pathname");
 		goto end;
 	}
 
@@ -52,6 +57,7 @@ enum ethash_io_rc ethash_io_prepare(
 			size_t found_size;
 			if (!ethash_file_size(f, &found_size)) {
 				fclose(f);
+				ETHASH_CRITICAL("Could not query size of DAG file: \"%s\"", tmpfile);
 				goto free_memo;
 			}
 			if (file_size != found_size - ETHASH_DAG_MAGIC_NUM_SIZE) {
@@ -64,6 +70,7 @@ enum ethash_io_rc ethash_io_prepare(
 			if (fread(&magic_num, ETHASH_DAG_MAGIC_NUM_SIZE, 1, f) != 1) {
 				// I/O error
 				fclose(f);
+				ETHASH_CRITICAL("Could not read from DAG file: \"%s\"", tmpfile);
 				ret = ETHASH_IO_MEMO_SIZE_MISMATCH;
 				goto free_memo;
 			}
@@ -80,15 +87,25 @@ enum ethash_io_rc ethash_io_prepare(
 	// file does not exist, will need to be created
 	f = ethash_fopen(tmpfile, "wb+");
 	if (!f) {
+		ETHASH_CRITICAL("Could not create DAG file: \"%s\"", tmpfile);
 		goto free_memo;
 	}
 	// make sure it's of the proper size
 	if (fseek(f, (long int)(file_size + ETHASH_DAG_MAGIC_NUM_SIZE - 1), SEEK_SET) != 0) {
 		fclose(f);
+		ETHASH_CRITICAL("Could not seek to the end of DAG file: \"%s\". Insufficient space?", tmpfile);
+		goto free_memo;
+	}
+	if (fputc('\n', f) == EOF) {
+		fclose(f);
+		ETHASH_CRITICAL("Could not write in the end of DAG file: \"%s\". Insufficient space?", tmpfile);
+		goto free_memo;
+	}
+	if (fflush(f) != 0) {
+		fclose(f);
+		ETHASH_CRITICAL("Could not flush at end of DAG file: \"%s\". Insufficient space?", tmpfile);
 		goto free_memo;
 	}
-	fputc('\n', f);
-	fflush(f);
 	ret = ETHASH_IO_MEMO_MISMATCH;
 	goto set_file;
 

libethash/io.h

@@ -54,6 +54,23 @@ enum ethash_io_rc {
 #define snprintf(...) sprintf_s(__VA_ARGS__)
 #endif
 
+/**
+ * Logs a critical error in important parts of ethash. Should mostly help
+ * figure out what kind of problem (I/O, memory e.t.c.) causes a NULL
+ * ethash_full_t
+ */
+#ifdef ETHASH_PRINT_CRITICAL_OUTPUT
+#define ETHASH_CRITICAL(...)							\
+	do													\
+	{													\
+		printf("ETHASH CRITICAL ERROR: "__VA_ARGS__);	\
+		printf("\n");									\
+		fflush(stdout);									\
+	} while (0)
+#else
+#define ETHASH_CRITICAL(...)          
+#endif
+
 /**
  * Prepares io for ethash
  *