From f71ddbb3fdf30bc8910ad734921d584d0459f7ac Mon Sep 17 00:00:00 2001
From: Andrea Mazzoleni <amadvance@gmail.com>
Date: Wed, 2 Dec 2015 23:21:33 +0100
Subject: [PATCH] Add backtrace support for internal errors

---
 cmdline/elem.c     | 24 +++++++++++------------
 cmdline/handle.c   |  2 +-
 cmdline/mingw.c    | 23 +++++++++++++++++++++++
 cmdline/portable.h | 14 ++++++++++++++
 cmdline/rehash.c   |  2 +-
 cmdline/scan.c     | 16 ++++++++--------
 cmdline/state.c    | 40 +++++++++++++++++++--------------------
 cmdline/unix.c     | 47 ++++++++++++++++++++++++++++++++++++++++++++++
 configure.ac       |  9 ++++++++-
 9 files changed, 134 insertions(+), 43 deletions(-)

diff --git a/cmdline/elem.c b/cmdline/elem.c
index 3e7d55cc..c1f8004b 100644
--- a/cmdline/elem.c
+++ b/cmdline/elem.c
@@ -425,21 +425,21 @@ void file_copy(struct snapraid_file* src_file, struct snapraid_file* dst_file)
 	if (src_file->size != dst_file->size) {
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency in copy file with different size\n");
-		exit(EXIT_FAILURE);
+		os_abort();
 		/* LCOV_EXCL_STOP */
 	}
 
 	if (src_file->mtime_sec != dst_file->mtime_sec) {
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency in copy file with different mtime_sec\n");
-		exit(EXIT_FAILURE);
+		os_abort();
 		/* LCOV_EXCL_STOP */
 	}
 
 	if (src_file->mtime_nsec != dst_file->mtime_nsec) {
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency in copy file with different mtime_nsec\n");
-		exit(EXIT_FAILURE);
+		os_abort();
 		/* LCOV_EXCL_STOP */
 	}
 
@@ -489,7 +489,7 @@ int file_block_is_last(struct snapraid_file* file, block_off_t file_pos)
 	if (file_pos >= file->blockmax) {
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency in file block position\n");
-		exit(EXIT_FAILURE);
+		os_abort();
 		/* LCOV_EXCL_STOP */
 	}
 
@@ -610,13 +610,13 @@ struct snapraid_chunk* chunk_alloc(block_off_t parity_pos, struct snapraid_file*
 	if (count == 0) {
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency when allocating empty chunk for file '%s' at position '%u/%u'\n", file->sub, file_pos, file->blockmax);
-		exit(EXIT_FAILURE);
+		os_abort();
 		/* LCOV_EXCL_STOP */
 	}
 	if (file_pos + count > file->blockmax) {
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency when allocating overflowing chunk for file '%s' at position '%u:%u/%u'\n", file->sub, file_pos, count, file->blockmax);
-		exit(EXIT_FAILURE);
+		os_abort();
 		/* LCOV_EXCL_STOP */
 	}
 
@@ -1162,7 +1162,7 @@ block_off_t fs_file2par_get_ts(struct snapraid_disk* disk, struct snapraid_chunk
 	if (!chunk) {
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency when resolving file '%s' at position '%u/%u' in disk '%s'\n", file->sub, file_pos, file->blockmax, disk->name);
-		exit(EXIT_FAILURE);
+		os_abort();
 		/* LCOV_EXCL_STOP */
 	}
 
@@ -1184,7 +1184,7 @@ void fs_allocate(struct snapraid_disk* disk, block_off_t parity_pos, struct snap
 			if (file_pos != chunk->file_pos + chunk->count) {
 				/* LCOV_EXCL_START */
 				log_fatal("Internal inconsistency when allocating file '%s' at position '%u/%u' in the middle of chunk '%u:%u' in disk '%s'\n", file->sub, file_pos, file->blockmax, chunk->file_pos, chunk->count, disk->name);
-				exit(EXIT_FAILURE);
+				os_abort();
 				/* LCOV_EXCL_STOP */
 			}
 
@@ -1205,7 +1205,7 @@ void fs_allocate(struct snapraid_disk* disk, block_off_t parity_pos, struct snap
 	if (parity_chunk != chunk || file_chunk != chunk) {
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency when allocating file '%s' at position '%u/%u' for existing chunk '%u:%u' in disk '%s'\n", file->sub, file_pos, file->blockmax, chunk->file_pos, chunk->count, disk->name);
-		exit(EXIT_FAILURE);
+		os_abort();
 		/* LCOV_EXCL_STOP */
 	}
 
@@ -1225,7 +1225,7 @@ void fs_deallocate(struct snapraid_disk* disk, block_off_t parity_pos)
 	if (!chunk) {
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency when deallocating parity position '%u' for not existing chunk in disk '%s'\n", parity_pos, disk->name);
-		exit(EXIT_FAILURE);
+		os_abort();
 		/* LCOV_EXCL_STOP */
 	}
 
@@ -1274,7 +1274,7 @@ void fs_deallocate(struct snapraid_disk* disk, block_off_t parity_pos)
 	if (parity_chunk != second_chunk || file_chunk != second_chunk) {
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency when deallocating parity position '%u' for splitting chunk '%u:%u' in disk '%s'\n", parity_pos, second_chunk->file_pos, second_chunk->count, disk->name);
-		exit(EXIT_FAILURE);
+		os_abort();
 		/* LCOV_EXCL_STOP */
 	}
 
@@ -1287,7 +1287,7 @@ struct snapraid_block* fs_file2block_get(struct snapraid_file* file, block_off_t
 	if (file_pos >= file->blockmax) {
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency when dereferencing file '%s' at position '%u/%u'\n", file->sub, file_pos, file->blockmax);
-		exit(EXIT_FAILURE);
+		os_abort();
 		/* LCOV_EXCL_STOP */
 	}
 
diff --git a/cmdline/handle.c b/cmdline/handle.c
index 0f211814..1bc2f86e 100644
--- a/cmdline/handle.c
+++ b/cmdline/handle.c
@@ -424,7 +424,7 @@ struct snapraid_handle* handle_map(struct snapraid_state* state, unsigned* handl
 		if (k == 0) {
 			/* LCOV_EXCL_START */
 			log_fatal("Internal error for inconsistent disk mapping.\n");
-			exit(EXIT_FAILURE);
+			os_abort();
 			/* LCOV_EXCL_STOP */
 		}
 
diff --git a/cmdline/mingw.c b/cmdline/mingw.c
index acf2e429..dde0b2f5 100644
--- a/cmdline/mingw.c
+++ b/cmdline/mingw.c
@@ -243,6 +243,29 @@ void os_done(void)
 	FreeLibrary(dll_advapi32);
 }
 
+void os_abort(void)
+{
+	void* stack[32];
+	size_t size;
+	unsigned i;
+
+	printf("Stacktrace of " PACKAGE " v" VERSION);
+	printf(", mingw");
+#ifdef __GNUC__
+	printf(", gcc " __VERSION__);
+#endif
+	printf(", %d-bit", (int)sizeof(void *) * 8);
+	printf("\n");
+
+	/* get stackstrace, but without symbols */
+	size = CaptureStackBackTrace(0, 32, stack, NULL);
+
+	for (i=0; i<size; ++i)
+		printf("[bt] %02u: %p\n", i, stack[i]);
+
+	abort();
+}
+
 /**
  * Size in chars of conversion buffers for u8to16() and u16to8().
  */
diff --git a/cmdline/portable.h b/cmdline/portable.h
index e295c1e9..81f2e789 100644
--- a/cmdline/portable.h
+++ b/cmdline/portable.h
@@ -69,6 +69,11 @@
 #define __always_inline inline __attribute__((always_inline))
 #endif
 
+#ifndef __noreturn
+#define __noreturn __attribute__((noreturn))
+#endif
+
+
 /**
  * Architecture.
  */
@@ -211,6 +216,10 @@
 #include <math.h>
 #endif
 
+#if HAVE_EXECINFO_H
+#include <execinfo.h>
+#endif
+
 /**
  * Disable case check in Windows.
  */
@@ -322,6 +331,11 @@ void os_init(int opt);
  */
 void os_done(void);
 
+/**
+ * Abort the process with a stacktrace.
+ */
+void os_abort(void) __noreturn;
+
 /**
  * Log file.
  *
diff --git a/cmdline/rehash.c b/cmdline/rehash.c
index f62c659d..ec903e16 100644
--- a/cmdline/rehash.c
+++ b/cmdline/rehash.c
@@ -77,7 +77,7 @@ void state_rehash(struct snapraid_state* state)
 		if (info_get_rehash(info)) {
 			/* LCOV_EXCL_START */
 			log_fatal("Internal inconsistency for a rehash already in progress\n");
-			exit(EXIT_FAILURE);
+			os_abort();
 			/* LCOV_EXCL_STOP */
 		}
 
diff --git a/cmdline/scan.c b/cmdline/scan.c
index 59ff0a78..f525da60 100644
--- a/cmdline/scan.c
+++ b/cmdline/scan.c
@@ -96,7 +96,7 @@ static void scan_link(struct snapraid_scan* scan, int is_diff, const char* sub,
 		if (link_flag_has(slink, FILE_IS_PRESENT)) {
 			/* LCOV_EXCL_START */
 			log_fatal("Internal inconsistency for link '%s%s'\n", disk->dir, sub);
-			exit(EXIT_FAILURE);
+			os_abort();
 			/* LCOV_EXCL_STOP */
 		}
 
@@ -275,7 +275,7 @@ static void scan_file_deallocate(struct snapraid_scan* scan, struct snapraid_fil
 	if (disk->first_free_block != 0) {
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency for first free position at '%u' deallocating file '%s'\n", disk->first_free_block, file->sub);
-		exit(EXIT_FAILURE);
+		os_abort();
 		/* LCOV_EXCL_STOP */
 	}
 
@@ -315,7 +315,7 @@ static void scan_file_deallocate(struct snapraid_scan* scan, struct snapraid_fil
 		default :
 			/* LCOV_EXCL_START */
 			log_fatal("Internal inconsistency in file '%s' deallocating block '%u:%u' state %u\n", file->sub, i, file->blockmax, block_state);
-			exit(EXIT_FAILURE);
+			os_abort();
 			/* LCOV_EXCL_STOP */
 		}
 
@@ -654,7 +654,7 @@ static void scan_file(struct snapraid_scan* scan, int is_diff, const char* sub,
 				if (st->st_nlink <= 1) {
 					/* LCOV_EXCL_START */
 					log_fatal("Internal inode '%" PRIu64 "' inconsistency for file '%s%s' already present\n", (uint64_t)st->st_ino, disk->dir, sub);
-					exit(EXIT_FAILURE);
+					os_abort();
 					/* LCOV_EXCL_STOP */
 				}
 #endif
@@ -722,7 +722,7 @@ static void scan_file(struct snapraid_scan* scan, int is_diff, const char* sub,
 		if (file_flag_has(file, FILE_IS_PRESENT)) {
 			/* LCOV_EXCL_START */
 			log_fatal("Internal inode '%" PRIu64 "' inconsistency for files '%s%s' and '%s%s' matching and already present but different\n", file->inode, disk->dir, sub, disk->dir, file->sub);
-			exit(EXIT_FAILURE);
+			os_abort();
 			/* LCOV_EXCL_STOP */
 		}
 
@@ -772,7 +772,7 @@ static void scan_file(struct snapraid_scan* scan, int is_diff, const char* sub,
 			if (file->inode == st->st_ino) {
 				/* LCOV_EXCL_START */
 				log_fatal("Internal inconsistency in inode '%" PRIu64 "' for files '%s%s' as unexpected matching\n", file->inode, disk->dir, sub);
-				exit(EXIT_FAILURE);
+				os_abort();
 				/* LCOV_EXCL_STOP */
 			}
 		}
@@ -781,7 +781,7 @@ static void scan_file(struct snapraid_scan* scan, int is_diff, const char* sub,
 		if (file_flag_has(file, FILE_IS_PRESENT)) {
 			/* LCOV_EXCL_START */
 			log_fatal("Internal inconsistency in path for file '%s%s' matching and already present\n", disk->dir, sub);
-			exit(EXIT_FAILURE);
+			os_abort();
 			/* LCOV_EXCL_STOP */
 		}
 
@@ -1011,7 +1011,7 @@ static void scan_emptydir(struct snapraid_scan* scan, const char* sub)
 		if (dir_flag_has(dir, FILE_IS_PRESENT)) {
 			/* LCOV_EXCL_START */
 			log_fatal("Internal inconsistency for dir '%s%s'\n", disk->dir, sub);
-			exit(EXIT_FAILURE);
+			os_abort();
 			/* LCOV_EXCL_STOP */
 		}
 
diff --git a/cmdline/state.c b/cmdline/state.c
index 1353998a..cfb6a888 100644
--- a/cmdline/state.c
+++ b/cmdline/state.c
@@ -1260,7 +1260,7 @@ static void state_map(struct snapraid_state* state)
 			if (disk == 0) {
 				/* LCOV_EXCL_START */
 				log_fatal("Internal inconsistency for mapping '%s'\n", map->name);
-				exit(EXIT_FAILURE);
+				os_abort();
 				/* LCOV_EXCL_STOP */
 			}
 
@@ -1390,7 +1390,7 @@ void state_refresh(struct snapraid_state* state)
 		if (disk == 0) {
 			/* LCOV_EXCL_START */
 			log_fatal("Internal inconsistency for mapping '%s'\n", map->name);
-			exit(EXIT_FAILURE);
+			os_abort();
 			/* LCOV_EXCL_STOP */
 		}
 
@@ -1670,7 +1670,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 				/* LCOV_EXCL_START */
 				decoding_error(path, f);
 				log_fatal("Internal inconsistency in mapping index!\n");
-				exit(EXIT_FAILURE);
+				os_abort();
 				/* LCOV_EXCL_STOP */
 			}
 			disk = tommy_array_get(&disk_mapping, mapping);
@@ -1688,7 +1688,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 				/* LCOV_EXCL_START */
 				decoding_error(path, f);
 				log_fatal("Internal inconsistency in file size too big!\n");
-				exit(EXIT_FAILURE);
+				os_abort();
 				/* LCOV_EXCL_STOP */
 			}
 
@@ -1774,7 +1774,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 					/* LCOV_EXCL_START */
 					decoding_error(path, f);
 					log_fatal("Internal inconsistency in block number!\n");
-					exit(EXIT_FAILURE);
+					os_abort();
 					/* LCOV_EXCL_STOP */
 				}
 
@@ -1782,7 +1782,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 					/* LCOV_EXCL_START */
 					log_fatal("Internal inconsistency in block size %u/%u!\n", blockmax, v_pos + v_count);
 					decoding_error(path, f);
-					exit(EXIT_FAILURE);
+					os_abort();
 					/* LCOV_EXCL_START */
 				}
 
@@ -1904,9 +1904,9 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 
 				if (v_pos + v_count > blockmax) {
 					/* LCOV_EXCL_START */
-					log_fatal("Internal inconsistency in info size %u/%u!\n", blockmax, v_pos + v_count);
 					decoding_error(path, f);
-					exit(EXIT_FAILURE);
+					log_fatal("Internal inconsistency in info size %u/%u!\n", blockmax, v_pos + v_count);
+					os_abort();
 					/* LCOV_EXCL_STOP */
 				}
 
@@ -1914,7 +1914,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 				if (ret < 0) {
 					/* LCOV_EXCL_START */
 					decoding_error(path, f);
-					exit(EXIT_FAILURE);
+					os_abort();
 					/* LCOV_EXCL_STOP */
 				}
 
@@ -1938,7 +1938,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 						/* LCOV_EXCL_START */
 						decoding_error(path, f);
 						log_fatal("Internal inconsistency for missing previous checksum!\n");
-						exit(EXIT_FAILURE);
+						os_abort();
 						/* LCOV_EXCL_STOP */
 					}
 
@@ -1957,7 +1957,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 							/* LCOV_EXCL_START */
 							decoding_error(path, f);
 							log_fatal("Internal inconsistency for missing info!\n");
-							exit(EXIT_FAILURE);
+							os_abort();
 							/* LCOV_EXCL_STOP */
 						}
 					} else {
@@ -1981,7 +1981,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 				/* LCOV_EXCL_START */
 				decoding_error(path, f);
 				log_fatal("Internal inconsistency in mapping index!\n");
-				exit(EXIT_FAILURE);
+				os_abort();
 				/* LCOV_EXCL_STOP */
 			}
 			disk = tommy_array_get(&disk_mapping, mapping);
@@ -1996,15 +1996,15 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 				if (ret < 0) {
 					/* LCOV_EXCL_START */
 					decoding_error(path, f);
-					exit(EXIT_FAILURE);
+					os_abort();
 					/* LCOV_EXCL_STOP */
 				}
 
 				if (v_pos + v_count > blockmax) {
 					/* LCOV_EXCL_START */
-					log_fatal("Internal inconsistency in hole size %u/%u!\n", blockmax, v_pos + v_count);
 					decoding_error(path, f);
-					exit(EXIT_FAILURE);
+					log_fatal("Internal inconsistency in hole size %u/%u!\n", blockmax, v_pos + v_count);
+					os_abort();
 					/* LCOV_EXCL_STOP */
 				}
 
@@ -2081,7 +2081,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 				/* LCOV_EXCL_START */
 				decoding_error(path, f);
 				log_fatal("Internal inconsistency in mapping index!\n");
-				exit(EXIT_FAILURE);
+				os_abort();
 				/* LCOV_EXCL_STOP */
 			}
 			disk = tommy_array_get(&disk_mapping, mapping);
@@ -2131,7 +2131,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 				/* LCOV_EXCL_START */
 				decoding_error(path, f);
 				log_fatal("Internal inconsistency in mapping index!\n");
-				exit(EXIT_FAILURE);
+				os_abort();
 				/* LCOV_EXCL_STOP */
 			}
 			disk = tommy_array_get(&disk_mapping, mapping);
@@ -2180,7 +2180,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 				/* LCOV_EXCL_START */
 				decoding_error(path, f);
 				log_fatal("Internal inconsistency in mapping index!\n");
-				exit(EXIT_FAILURE);
+				os_abort();
 				/* LCOV_EXCL_STOP */
 			}
 			disk = tommy_array_get(&disk_mapping, mapping);
@@ -3051,7 +3051,7 @@ static void state_write_content(struct snapraid_state* state, uint32_t* out_crc)
 		if (!disk) {
 			/* LCOV_EXCL_START */
 			log_fatal("Internal inconsistency for unmapped disk '%s'\n", map->name);
-			exit(EXIT_FAILURE);
+			os_abort();
 			/* LCOV_EXCL_STOP */
 		}
 
@@ -3908,7 +3908,7 @@ void state_fscheck(struct snapraid_state* state, const char* ope)
 		if (fs_check(disk) != 0) {
 			/* LCOV_EXCL_START */
 			log_fatal("Internal inconsistency in filesystem for disk '%s' %s\n", disk->name, ope);
-			exit(EXIT_FAILURE);
+			os_abort();
 			/* LCOV_EXCL_STOP */
 		}
 	}
diff --git a/cmdline/unix.c b/cmdline/unix.c
index 9d7ff0d6..7ea37c9e 100644
--- a/cmdline/unix.c
+++ b/cmdline/unix.c
@@ -1012,5 +1012,52 @@ void os_done(void)
 {
 }
 
+void os_abort(void)
+{
+#if HAVE_BACKTRACE && HAVE_BACKTRACE_SYMBOLS
+	void* stack[32];
+	char** messages;
+	size_t size;
+	unsigned i;
+
+	printf("Stacktrace of " PACKAGE " v" VERSION);
+#ifdef _linux
+	printf(", linux");
+#endif
+#ifdef __GNUC__
+	printf(", gcc " __VERSION__);
+#endif
+	printf(", %d-bit", (int)sizeof(void *) * 8);
+	printf("\n");
+
+	size = backtrace(stack, 32);
+
+	messages = backtrace_symbols(stack, size);
+
+	for (i=1; i<size; ++i) {
+		const char* msg;
+
+		if (messages)
+			msg = messages[i];
+		else
+			msg = "<unknown>";
+
+		printf("[bt] %02u: %s\n", i, msg);
+
+		if (messages) {
+			char addr2line[1024];
+			size_t j = 0;
+			while (msg[j] != '(' && msg[j] != ' ' && msg[j] != 0)
+				++j;
+
+			snprintf(addr2line, sizeof(addr2line), "addr2line %p -e %.*s", stack[i], j, msg);
+			system(addr2line);
+		}
+	}
+#endif
+
+	abort();
+}
+
 #endif
 
diff --git a/configure.ac b/configure.ac
index 0b472fa7..20f263fc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,6 +17,12 @@ AC_CHECK_PROG([SDE],[sde],[sde],[])
 AC_CHECK_PROG([ADVD2],[advd2],[advd2],[])
 AM_CONDITIONAL(HAVE_ADVD2, [test x"$ADVD2" != x])
 
+dnl Compiler option to improve stacktrace
+AC_CHECK_CC_OPT([-fno-omit-frame-pointer], CFLAGS="$CFLAGS -fno-omit-frame-pointer", [])
+AC_CHECK_CC_OPT([-fno-inline-functions-called-once], CFLAGS="$CFLAGS -fno-inline-functions-called-once", [])
+AC_CHECK_CC_OPT([-fno-inline-small-functions], CFLAGS="$CFLAGS -fno-inline-small-functions", [])
+AC_CHECK_CC_OPT([-rdynamic], CFLAGS="$CFLAGS -rdynamic", [])
+
 dnl Checks for system.
 AC_SYS_LARGEFILE
 
@@ -29,7 +35,7 @@ AC_CHECK_HEADERS([fcntl.h stddef.h stdint.h stdlib.h string.h limits.h])
 AC_CHECK_HEADERS([unistd.h getopt.h fnmatch.h io.h inttypes.h byteswap.h])
 AC_CHECK_HEADERS([pthread.h math.h])
 AC_CHECK_HEADERS([sys/file.h sys/ioctl.h sys/vfs.h sys/statfs.h sys/param.h sys/mount.h])
-AC_CHECK_HEADERS([linux/fiemap.h linux/fs.h mach/mach_time.h])
+AC_CHECK_HEADERS([linux/fiemap.h linux/fs.h mach/mach_time.h execinfo.h])
 
 dnl Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
@@ -80,6 +86,7 @@ AC_CHECK_FUNCS([pread pwrite getc_unlocked ferror_unlocked fnmatch])
 AC_CHECK_FUNCS([futimes futimens futimesat localtime_r])
 AC_CHECK_FUNCS([fstatat flock statfs])
 AC_CHECK_FUNCS([mach_absolute_time])
+AC_CHECK_FUNCS([backtrace backtrace_symbols])
 AC_SEARCH_LIBS([clock_gettime], [rt])
 AC_CHECK_FUNCS([clock_gettime])
 AC_CHECK_CC_OPT([-pthread], CFLAGS="$CFLAGS -pthread", [])