Merge pull request #60 from tomerd/fix/flush

flush stderr after printing backtraces

README.md

@@ -2,8 +2,14 @@
 
 This Swift package provides support for automatically printing crash backtraces of Swift programs.
 
+The library is designed to fill a gap in backtraces support for Swift on non-Darwin platforms. 
+When this gap is closed at the language runtime level, this library will become redundant and be deprecated.
+
 ## Usage
 
+When building web-services and daemons, direct usage of this library is discouraged. 
+Instead, use [swift-service-lifecycle](https://github.com/swift-server/swift-service-lifecycle) which helps manage the application lifecycle including setting up backtraces hooks when needed. 
+
 Add `https://github.com/swift-server/swift-backtrace.git` as a dependency in your `Package.swift`.
 
 ### Crash backtraces
@@ -25,6 +31,9 @@ $ swift build -c release -Xswiftc -g
 
 When your app crashes, a stacktrace will be printed to `stderr`.
 
+## Security
+
+Please see [SECURITY.md](SECURITY.md) for details on the security process.
 
 ## Acknowledgements
 

SECURITY.md

@@ -0,0 +1,43 @@
+# Security
+
+This document specifies the security process for the Backtrace project.
+
+## Disclosures
+
+### Private Disclosure Process
+
+The Backtrace maintainers ask that known and suspected vulnerabilities be
+privately and responsibly disclosed by emailing
+[sswg-security-reports@forums.swift.org](mailto:sswg-security-reports@forums.swift.org)
+with the all the required detail.
+**Do not file a public issue.**
+
+#### When to report a vulnerability
+
+* You think you have discovered a potential security vulnerability in Backtrace.
+* You are unsure how a vulnerability affects Backtrace.
+
+#### What happens next?
+
+* A member of the team will acknowledge receipt of the report within 3
+  working days (United States). This may include a request for additional
+  information about reproducing the vulnerability.
+* We will privately inform the Swift Server Work Group ([SSWG][sswg]) of the
+  vulnerability within 10 days of the report as per their [security
+  guidelines][sswg-security].
+* Once we have identified a fix we may ask you to validate it. We aim to do this
+  within 30 days. In some cases this may not be possible, for example when the
+  vulnerability exists at the protocol level and the industry must coordinate on
+  the disclosure process.
+* If a CVE number is required, one will be requested from [MITRE][mitre]
+  providing you with full credit for the discovery.
+* We will decide on a planned release date and let you know when it is.
+* Prior to release, we will inform major dependents that a security-related
+  patch is impending.
+* Once the fix has been released we will publish a security advisory on GitHub
+  and in the Server → Security Updates category on the [Swift forums][swift-forums-sec].
+
+[sswg]: https://github.com/swift-server/sswg
+[sswg-security]: https://github.com/swift-server/sswg/blob/main/security/README.md
+[swift-forums-sec]: https://forums.swift.org/c/server/security-updates/
+[mitre]: https://cveform.mitre.org/

Sources/Backtrace/Backtrace.swift

@@ -61,10 +61,25 @@ private let errorCallback: CBacktraceErrorCallback? = {
     }
 }
 
+private func printBacktrace(signal: CInt) {
+    _ = fputs("Received signal \(signal). Backtrace:\n", stderr)
+    backtrace_full(state, /* skip */ 0, fullCallback, errorCallback, nil)
+    fflush(stderr)
+}
+
 public enum Backtrace {
+    /// Install the backtrace handler on default signals: `SIGILL`, `SIGSEGV`, `SIGBUS`, `SIGFPE`.
     public static func install() {
-        self.setupHandler(signal: SIGILL) { _ in
-            backtrace_full(state, /* skip */ 0, fullCallback, errorCallback, nil)
+        Backtrace.install(signals: [SIGILL, SIGSEGV, SIGBUS, SIGFPE])
+    }
+
+    /// Install the backtrace handler when any of `signals` happen.
+    public static func install(signals: [CInt]) {
+        for signal in signals {
+            self.setupHandler(signal: signal) { signal in
+                printBacktrace(signal: signal)
+                raise(signal)
+            }
         }
     }
 
@@ -109,6 +124,11 @@ public enum Backtrace {
         #endif
     }
 
+    @available(*, deprecated, message: "signal selection unavailable on Windows")
+    public static func install(signals: [CInt]) {
+        Backtrace.install()
+    }
+
     public static func install() {
         // Install a last-chance vectored exception handler to capture the error
         // before the termination and report the stack trace.  It is unlikely
@@ -246,6 +266,8 @@ public enum Backtrace {
 public enum Backtrace {
     public static func install() {}
 
+    public static func install(signals: [CInt]) {}
+
     @available(*, deprecated, message: "This method will be removed in the next major version.")
     public static func print() {}
 }

Sources/Backtrace/Demangle.swift

@@ -23,6 +23,7 @@ import ucrt
 #endif
 #endif
 
+#if os(Linux) || os(Windows)
 @_silgen_name("swift_demangle")
 public
 func _stdlib_demangleImpl(
@@ -53,3 +54,4 @@ internal func _stdlib_demangleName(_ mangledName: String) -> String {
         return mangledName
     }
 }
+#endif

Sources/CBacktrace/atomic.c

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* atomic.c -- Support for atomic functions if not present.
-   Copyright (C) 2013-2018 Free Software Foundation, Inc.
+   Copyright (C) 2013-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without

Sources/CBacktrace/backtrace-supported.h

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* backtrace-supported.h.in -- Whether stack backtrace is supported.
-   Copyright (C) 2012-2016 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without

Sources/CBacktrace/backtrace.c

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* backtrace.c -- Entry point for stack backtrace library.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without
@@ -99,7 +99,7 @@ unwind (struct _Unwind_Context *context, void *vdata)
 
 /* Get a stack backtrace.  */
 
-int
+int __attribute__((noinline))
 backtrace_full (struct backtrace_state *state, int skip,
 		backtrace_full_callback callback,
 		backtrace_error_callback error_callback, void *data)

Sources/CBacktrace/config.h

@@ -14,6 +14,10 @@
 /* Define to 1 if you have the `clock_gettime' function. */
 #define HAVE_CLOCK_GETTIME 1
 
+/* Define to 1 if you have the declaration of `getpagesize', and to 0 if you
+   don't. */
+#define HAVE_DECL_GETPAGESIZE 1
+
 /* Define to 1 if you have the declaration of `strnlen', and to 0 if you
    don't. */
 #define HAVE_DECL_STRNLEN 1
@@ -36,8 +40,16 @@
 /* Define to 1 if you have the <inttypes.h> header file. */
 #define HAVE_INTTYPES_H 1
 
-/* Define to 1 if you have the `z' library (-lz). */
-/* #undef HAVE_LIBZ */
+/* Define to 1 if you have KERN_PROC and KERN_PROC_PATHNAME in <sys/sysctl.h>.
+   */
+/* #undef HAVE_KERN_PROC */
+
+/* Define to 1 if you have KERN_PROCARGS and KERN_PROC_PATHNAME in
+   <sys/sysctl.h>. */
+/* #undef HAVE_KERN_PROC_ARGS */
+
+/* Define if -llzma is available. */
+/* #undef HAVE_LIBLZMA */
 
 /* Define to 1 if you have the <link.h> header file. */
 #define HAVE_LINK_H 1
@@ -48,6 +60,9 @@
 /* Define to 1 if you have the `lstat' function. */
 #define HAVE_LSTAT 1
 
+/* Define to 1 if you have the <mach-o/dyld.h> header file. */
+/* #undef HAVE_MACH_O_DYLD_H */
+
 /* Define to 1 if you have the <memory.h> header file. */
 #define HAVE_MEMORY_H 1
 
@@ -85,7 +100,7 @@
 #define HAVE_UNISTD_H 1
 
 /* Define if -lz is available. */
-/* #undef HAVE_ZLIB */
+#define HAVE_ZLIB 1
 
 /* Define to the sub-directory in which libtool stores uninstalled libraries.
    */
@@ -134,6 +149,11 @@
 #endif
 
 
+/* Enable large inode numbers on Mac OS X 10.5.  */
+#ifndef _DARWIN_USE_64_BIT_INODE
+# define _DARWIN_USE_64_BIT_INODE 1
+#endif
+
 /* Number of bits in a file offset, on hosts where this is settable. */
 /* #undef _FILE_OFFSET_BITS */
 

Sources/CBacktrace/fileline.c

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* fileline.c -- Get file and line number information in a backtrace.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without
@@ -40,6 +40,14 @@ POSSIBILITY OF SUCH DAMAGE.  */
 #include <stdlib.h>
 #include <unistd.h>
 
+#if defined (HAVE_KERN_PROC_ARGS) || defined (HAVE_KERN_PROC)
+#include <sys/sysctl.h>
+#endif
+
+#ifdef HAVE_MACH_O_DYLD_H
+#include <mach-o/dyld.h>
+#endif
+
 #include "include/backtrace.h"
 #include "internal.h"
 
@@ -47,6 +55,107 @@ POSSIBILITY OF SUCH DAMAGE.  */
 #define getexecname() NULL
 #endif
 
+#if !defined (HAVE_KERN_PROC_ARGS) && !defined (HAVE_KERN_PROC)
+
+#define sysctl_exec_name1(state, error_callback, data) NULL
+#define sysctl_exec_name2(state, error_callback, data) NULL
+
+#else /* defined (HAVE_KERN_PROC_ARGS) || |defined (HAVE_KERN_PROC) */
+
+static char *
+sysctl_exec_name (struct backtrace_state *state,
+		  int mib0, int mib1, int mib2, int mib3,
+		  backtrace_error_callback error_callback, void *data)
+{
+  int mib[4];
+  size_t len;
+  char *name;
+  size_t rlen;
+
+  mib[0] = mib0;
+  mib[1] = mib1;
+  mib[2] = mib2;
+  mib[3] = mib3;
+
+  if (sysctl (mib, 4, NULL, &len, NULL, 0) < 0)
+    return NULL;
+  name = (char *) backtrace_alloc (state, len, error_callback, data);
+  if (name == NULL)
+    return NULL;
+  rlen = len;
+  if (sysctl (mib, 4, name, &rlen, NULL, 0) < 0)
+    {
+      backtrace_free (state, name, len, error_callback, data);
+      return NULL;
+    }
+  return name;
+}
+
+#ifdef HAVE_KERN_PROC_ARGS
+
+static char *
+sysctl_exec_name1 (struct backtrace_state *state,
+		   backtrace_error_callback error_callback, void *data)
+{
+  /* This variant is used on NetBSD.  */
+  return sysctl_exec_name (state, CTL_KERN, KERN_PROC_ARGS, -1,
+			   KERN_PROC_PATHNAME, error_callback, data);
+}
+
+#else
+
+#define sysctl_exec_name1(state, error_callback, data) NULL
+
+#endif
+
+#ifdef HAVE_KERN_PROC
+
+static char *
+sysctl_exec_name2 (struct backtrace_state *state,
+		   backtrace_error_callback error_callback, void *data)
+{
+  /* This variant is used on FreeBSD.  */
+  return sysctl_exec_name (state, CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1,
+			   error_callback, data);
+}
+
+#else
+
+#define sysctl_exec_name2(state, error_callback, data) NULL
+
+#endif
+
+#endif /* defined (HAVE_KERN_PROC_ARGS) || |defined (HAVE_KERN_PROC) */
+
+#ifdef HAVE_MACH_O_DYLD_H
+
+static char *
+macho_get_executable_path (struct backtrace_state *state,
+			   backtrace_error_callback error_callback, void *data)
+{
+  uint32_t len;
+  char *name;
+
+  len = 0;
+  if (_NSGetExecutablePath (NULL, &len) == 0)
+    return NULL;
+  name = (char *) backtrace_alloc (state, len, error_callback, data);
+  if (name == NULL)
+    return NULL;
+  if (_NSGetExecutablePath (name, &len) != 0)
+    {
+      backtrace_free (state, name, len, error_callback, data);
+      return NULL;
+    }
+  return name;
+}
+
+#else /* !defined (HAVE_MACH_O_DYLD_H) */
+
+#define macho_get_executable_path(state, error_callback, data) NULL
+
+#endif /* !defined (HAVE_MACH_O_DYLD_H) */
+
 /* Initialize the fileline information from the executable.  Returns 1
    on success, 0 on failure.  */
 
@@ -84,7 +193,7 @@ fileline_initialize (struct backtrace_state *state,
 
   descriptor = -1;
   called_error_callback = 0;
-  for (pass = 0; pass < 5; ++pass)
+  for (pass = 0; pass < 8; ++pass)
     {
       int does_not_exist;
 
@@ -94,19 +203,28 @@ fileline_initialize (struct backtrace_state *state,
 	  filename = state->filename;
 	  break;
 	case 1:
-	  filename = "/proc/self/exe";
+	  filename = getexecname ();
 	  break;
 	case 2:
-	  filename = "/proc/curproc/file";
+	  filename = "/proc/self/exe";
 	  break;
 	case 3:
-	  filename = getexecname ();
+	  filename = "/proc/curproc/file";
 	  break;
 	case 4:
 	  snprintf (buf, sizeof (buf), "/proc/%ld/object/a.out",
 		    (long) getpid ());
 	  filename = buf;
 	  break;
+	case 5:
+	  filename = sysctl_exec_name1 (state, error_callback, data);
+	  break;
+	case 6:
+	  filename = sysctl_exec_name2 (state, error_callback, data);
+	  break;
+	case 7:
+	  filename = macho_get_executable_path (state, error_callback, data);
+	  break;
 	default:
 	  abort ();
 	}
@@ -200,4 +318,31 @@ backtrace_syminfo (struct backtrace_state *state, uintptr_t pc,
   state->syminfo_fn (state, pc, callback, error_callback, data);
   return 1;
 }
+
+/* A backtrace_syminfo_callback that can call into a
+   backtrace_full_callback, used when we have a symbol table but no
+   debug info.  */
+
+void
+backtrace_syminfo_to_full_callback (void *data, uintptr_t pc,
+				    const char *symname,
+				    uintptr_t symval ATTRIBUTE_UNUSED,
+				    uintptr_t symsize ATTRIBUTE_UNUSED)
+{
+  struct backtrace_call_full *bdata = (struct backtrace_call_full *) data;
+
+  bdata->ret = bdata->full_callback (bdata->full_data, pc, NULL, 0, symname);
+}
+
+/* An error callback that corresponds to
+   backtrace_syminfo_to_full_callback.  */
+
+void
+backtrace_syminfo_to_full_error_callback (void *data, const char *msg,
+					  int errnum)
+{
+  struct backtrace_call_full *bdata = (struct backtrace_call_full *) data;
+
+  bdata->full_error_callback (bdata->full_data, msg, errnum);
+}
 #endif

Sources/CBacktrace/filenames.h

@@ -45,7 +45,10 @@ POSSIBILITY OF SUCH DAMAGE.  */
 
 #if defined(__MSDOS__) || defined(_WIN32) || defined(__OS2__) || defined (__CYGWIN__)
 # define IS_DIR_SEPARATOR(c) ((c) == '/' || (c) == '\\')
+# define HAS_DRIVE_SPEC(f) ((f)[0] != '\0' && (f)[1] == ':')
+# define IS_ABSOLUTE_PATH(f) (IS_DIR_SEPARATOR((f)[0]) || HAS_DRIVE_SPEC(f))
 #else
 # define IS_DIR_SEPARATOR(c) ((c) == '/')
+# define IS_ABSOLUTE_PATH(f) (IS_DIR_SEPARATOR((f)[0]))
 #endif
 #endif

Sources/CBacktrace/include/backtrace.h

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* backtrace.h -- Public header file for stack backtrace library.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without
@@ -55,13 +55,14 @@ struct backtrace_state;
    invalid after this function returns.
 
    As a special case, the ERRNUM argument will be passed as -1 if no
-   debug info can be found for the executable, but the function
-   requires debug info (e.g., backtrace_full, backtrace_pcinfo).  The
-   MSG in this case will be something along the lines of "no debug
-   info".  Similarly, ERRNUM will be passed as -1 if there is no
-   symbol table, but the function requires a symbol table (e.g.,
-   backtrace_syminfo).  This may be used as a signal that some other
-   approach should be tried.  */
+   debug info can be found for the executable, or if the debug info
+   exists but has an unsupported version, but the function requires
+   debug info (e.g., backtrace_full, backtrace_pcinfo).  The MSG in
+   this case will be something along the lines of "no debug info".
+   Similarly, ERRNUM will be passed as -1 if there is no symbol table,
+   but the function requires a symbol table (e.g., backtrace_syminfo).
+   This may be used as a signal that some other approach should be
+   tried.  */
 
 typedef void (*backtrace_error_callback) (void *data, const char *msg,
 					  int errnum);
@@ -76,7 +77,13 @@ typedef void (*backtrace_error_callback) (void *data, const char *msg,
    use appropriate atomic operations.  If THREADED is zero the state
    may only be accessed by one thread at a time.  This returns a state
    pointer on success, NULL on error.  If an error occurs, this will
-   call the ERROR_CALLBACK routine.  */
+   call the ERROR_CALLBACK routine.
+
+   Calling this function allocates resources that cannot be freed.
+   There is no backtrace_free_state function.  The state is used to
+   cache information that is expensive to recompute.  Programs are
+   expected to call this function at most once and to save the return
+   value for all later calls to backtrace functions.  */
 
 extern struct backtrace_state *backtrace_create_state (
     const char *filename, int threaded,

Sources/CBacktrace/internal.h

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* internal.h -- Internal header file for stack backtrace library.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without
@@ -57,6 +57,14 @@ POSSIBILITY OF SUCH DAMAGE.  */
 # endif
 #endif
 
+#ifndef ATTRIBUTE_FALLTHROUGH
+# if (GCC_VERSION >= 7000)
+#  define ATTRIBUTE_FALLTHROUGH __attribute__ ((__fallthrough__))
+# else
+#  define ATTRIBUTE_FALLTHROUGH
+# endif
+#endif
+
 #ifndef HAVE_SYNC_FUNCTIONS
 
 /* Define out the sync functions.  These should never be called if
@@ -180,7 +188,7 @@ struct backtrace_view
 /* Create a view of SIZE bytes from DESCRIPTOR at OFFSET.  Store the
    result in *VIEW.  Returns 1 on success, 0 on error.  */
 extern int backtrace_get_view (struct backtrace_state *state, int descriptor,
-			       off_t offset, size_t size,
+			       off_t offset, uint64_t size,
 			       backtrace_error_callback error_callback,
 			       void *data, struct backtrace_view *view);
 
@@ -258,6 +266,18 @@ extern int backtrace_vector_release (struct backtrace_state *state,
 				     backtrace_error_callback error_callback,
 				     void *data);
 
+/* Free the space managed by VEC.  This will reset VEC.  */
+
+static inline void
+backtrace_vector_free (struct backtrace_state *state,
+		       struct backtrace_vector *vec,
+		       backtrace_error_callback error_callback, void *data)
+{
+  vec->alc += vec->size;
+  vec->size = 0;
+  backtrace_vector_release (state, vec, error_callback, data);
+}
+
 /* Read initial debug data from a descriptor, and set the
    fileline_data, syminfo_fn, and syminfo_data fields of STATE.
    Return the fileln_fn field in *FILELN_FN--this is done this way so
@@ -275,23 +295,70 @@ extern int backtrace_initialize (struct backtrace_state *state,
 				 void *data,
 				 fileline *fileline_fn);
 
+/* An enum for the DWARF sections we care about.  */
+
+enum dwarf_section
+{
+  DEBUG_INFO,
+  DEBUG_LINE,
+  DEBUG_ABBREV,
+  DEBUG_RANGES,
+  DEBUG_STR,
+  DEBUG_ADDR,
+  DEBUG_STR_OFFSETS,
+  DEBUG_LINE_STR,
+  DEBUG_RNGLISTS,
+
+  DEBUG_MAX
+};
+
+/* Data for the DWARF sections we care about.  */
+
+struct dwarf_sections
+{
+  const unsigned char *data[DEBUG_MAX];
+  size_t size[DEBUG_MAX];
+};
+
+/* DWARF data read from a file, used for .gnu_debugaltlink.  */
+
+struct dwarf_data;
+
 /* Add file/line information for a DWARF module.  */
 
 extern int backtrace_dwarf_add (struct backtrace_state *state,
 				uintptr_t base_address,
-				const unsigned char* dwarf_info,
-				size_t dwarf_info_size,
-				const unsigned char *dwarf_line,
-				size_t dwarf_line_size,
-				const unsigned char *dwarf_abbrev,
-				size_t dwarf_abbrev_size,
-				const unsigned char *dwarf_ranges,
-				size_t dwarf_range_size,
-				const unsigned char *dwarf_str,
-				size_t dwarf_str_size,
+				const struct dwarf_sections *dwarf_sections,
 				int is_bigendian,
+				struct dwarf_data *fileline_altlink,
 				backtrace_error_callback error_callback,
-				void *data, fileline *fileline_fn);
+				void *data, fileline *fileline_fn,
+				struct dwarf_data **fileline_entry);
+
+/* A data structure to pass to backtrace_syminfo_to_full.  */
+
+struct backtrace_call_full
+{
+  backtrace_full_callback full_callback;
+  backtrace_error_callback full_error_callback;
+  void *full_data;
+  int ret;
+};
+
+/* A backtrace_syminfo_callback that can call into a
+   backtrace_full_callback, used when we have a symbol table but no
+   debug info.  */
+
+extern void backtrace_syminfo_to_full_callback (void *data, uintptr_t pc,
+						const char *symname,
+						uintptr_t symval,
+						uintptr_t symsize);
+
+/* An error callback that corresponds to
+   backtrace_syminfo_to_full_callback.  */
+
+extern void backtrace_syminfo_to_full_error_callback (void *, const char *,
+						      int);
 
 /* A test-only hook for elf_uncompress_zdebug.  */
 
@@ -302,5 +369,14 @@ extern int backtrace_uncompress_zdebug (struct backtrace_state *,
 					unsigned char **uncompressed,
 					size_t *uncompressed_size);
 
+/* A test-only hook for elf_uncompress_lzma.  */
+
+extern int backtrace_uncompress_lzma (struct backtrace_state *,
+				      const unsigned char *compressed,
+				      size_t compressed_size,
+				      backtrace_error_callback, void *data,
+				      unsigned char **uncompressed,
+				      size_t *uncompressed_size);
+
 #endif
 #endif

Sources/CBacktrace/mmap.c

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* mmap.c -- Memory allocation with mmap.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without
@@ -43,6 +43,10 @@ POSSIBILITY OF SUCH DAMAGE.  */
 #include "include/backtrace.h"
 #include "internal.h"
 
+#ifndef HAVE_DECL_GETPAGESIZE
+extern int getpagesize (void);
+#endif
+
 /* Memory allocation on systems that provide anonymous mmap.  This
    permits the backtrace functions to be invoked from a signal
    handler, assuming that mmap is async-signal safe.  */
@@ -170,7 +174,7 @@ backtrace_alloc (struct backtrace_state *state,
       if (page == MAP_FAILED)
 	{
 	  if (error_callback)
-	    error_callback (data, "mmap for alloc", errno);
+	    error_callback (data, "mmap", errno);
 	}
       else
 	{
@@ -322,6 +326,8 @@ backtrace_vector_release (struct backtrace_state *state,
   backtrace_free (state, (char *) vec->base + aligned, alc,
 		  error_callback, data);
   vec->alc = 0;
+  if (vec->size == 0)
+    vec->base = NULL;
   return 1;
 }
 #endif

Sources/CBacktrace/mmapio.c

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* mmapio.c -- File views using mmap.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without
@@ -41,6 +41,10 @@ POSSIBILITY OF SUCH DAMAGE.  */
 #include "include/backtrace.h"
 #include "internal.h"
 
+#ifndef HAVE_DECL_GETPAGESIZE
+extern int getpagesize (void);
+#endif
+
 #ifndef MAP_FAILED
 #define MAP_FAILED ((void *)-1)
 #endif
@@ -52,7 +56,7 @@ POSSIBILITY OF SUCH DAMAGE.  */
 
 int
 backtrace_get_view (struct backtrace_state *state ATTRIBUTE_UNUSED,
-		    int descriptor, off_t offset, size_t size,
+		    int descriptor, off_t offset, uint64_t size,
 		    backtrace_error_callback error_callback,
 		    void *data, struct backtrace_view *view)
 {
@@ -61,6 +65,12 @@ backtrace_get_view (struct backtrace_state *state ATTRIBUTE_UNUSED,
   off_t pageoff;
   void *map;
 
+  if ((uint64_t) (size_t) size != size)
+    {
+      error_callback (data, "file size too large", 0);
+      return 0;
+    }
+
   pagesize = getpagesize ();
   inpage = offset % pagesize;
   pageoff = offset - inpage;
@@ -71,7 +81,7 @@ backtrace_get_view (struct backtrace_state *state ATTRIBUTE_UNUSED,
   map = mmap (NULL, size, PROT_READ, MAP_PRIVATE, descriptor, pageoff);
   if (map == MAP_FAILED)
     {
-      error_callback (data, "mmap file i/o", errno);
+      error_callback (data, "mmap", errno);
       return 0;
     }
 

Sources/CBacktrace/posix.c

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* posix.c -- POSIX file I/O routines for the backtrace library.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without
@@ -68,7 +68,11 @@ backtrace_open (const char *filename, backtrace_error_callback error_callback,
   descriptor = open (filename, (int) (O_RDONLY | O_BINARY | O_CLOEXEC));
   if (descriptor < 0)
     {
-      if (does_not_exist != NULL && errno == ENOENT)
+      /* If DOES_NOT_EXIST is not NULL, then don't call ERROR_CALLBACK
+	 if the file does not exist.  We treat lacking permission to
+	 open the file as the file not existing; this case arises when
+	 running the libgo syscall package tests as root.  */
+      if (does_not_exist != NULL && (errno == ENOENT || errno == EACCES))
 	*does_not_exist = 1;
       else
 	error_callback (data, filename, errno);

Sources/CBacktrace/print.c

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* print.c -- Print the current backtrace.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without
@@ -81,7 +81,7 @@ error_callback (void *data, const char *msg, int errnum)
 
 /* Print a backtrace.  */
 
-void
+void __attribute__((noinline))
 backtrace_print (struct backtrace_state *state, int skip, FILE *f)
 {
   struct print_data data;

Sources/CBacktrace/simple.c

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* simple.c -- The backtrace_simple function.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without
@@ -56,7 +56,7 @@ struct backtrace_simple_data
   int ret;
 };
 
-/* Unwind library callback routine.  This is passd to
+/* Unwind library callback routine.  This is passed to
    _Unwind_Backtrace.  */
 
 static _Unwind_Reason_Code
@@ -91,7 +91,7 @@ simple_unwind (struct _Unwind_Context *context, void *vdata)
 
 /* Get a simple stack backtrace.  */
 
-int
+int __attribute__((noinline))
 backtrace_simple (struct backtrace_state *state, int skip,
 		  backtrace_simple_callback callback,
 		  backtrace_error_callback error_callback, void *data)

Sources/CBacktrace/sort.c

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* sort.c -- Sort without allocating memory
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without

Sources/CBacktrace/state.c

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* state.c -- Create the backtrace state.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without

Sources/Sample/main.swift

@@ -13,7 +13,28 @@
 //===----------------------------------------------------------------------===//
 
 import Backtrace
+#if canImport(Darwin)
+import Darwin
+#elseif os(Linux)
+import Glibc
+#endif
+
+Backtrace.install()
+
+func raiseSignal(_ signal: Int32) {
+    raise(signal)
+}
 
 let reason = CommandLine.arguments.count == 2 ? CommandLine.arguments[1] : "unknown"
-Backtrace.install()
-fatalError(reason)
+switch reason.uppercased() {
+case "SIGILL":
+    raiseSignal(SIGILL)
+case "SIGSEGV":
+    raiseSignal(SIGSEGV)
+case "SIGBUS":
+    raiseSignal(SIGBUS)
+case "SIGFPE":
+    raiseSignal(SIGFPE)
+default:
+    fatalError(reason)
+}

Tests/BacktraceTests/BacktraceTests+XCTest.swift

@@ -25,7 +25,11 @@ import XCTest
 extension BacktraceTests {
     public static var allTests: [(String, (BacktraceTests) -> () throws -> Void)] {
         return [
-            ("testBacktrace", testBacktrace),
+            ("testFatalError", testFatalError),
+            ("testSIGILL", testSIGILL),
+            ("testSIGSEGV", testSIGSEGV),
+            ("testSIGBUS", testSIGBUS),
+            ("testSIGFPE", testSIGFPE),
         ]
     }
 }

Tests/BacktraceTests/BacktraceTests.swift

@@ -15,22 +15,76 @@
 import XCTest
 
 public final class BacktraceTests: XCTestCase {
-    func testBacktrace() {
-        #if os(Linux)
+    func testFatalError() throws {
+        #if !os(Linux)
+        try XCTSkipIf(true, "test is only supported on Linux")
+        #endif
+
         let expectedError = UUID().uuidString
+        let stderr = try runSample(reason: expectedError)
+        print(stderr)
+
+        XCTAssert(stderr.contains("Received signal 4. Backtrace:"))
+        XCTAssert(stderr.contains("Current stack trace:"), "expected stanard error to include backtrace")
+        XCTAssert(stderr.contains("Fatal error: \(expectedError)"), "expected stanard error to include error information")
+    }
+
+    func testSIGILL() throws {
+        #if !os(Linux)
+        try XCTSkipIf(true, "test is only supported on Linux")
+        #endif
+
+        let stderr = try runSample(reason: "SIGILL")
+        print(stderr)
+
+        XCTAssert(stderr.contains("Received signal \(SIGILL). Backtrace:"))
+        XCTAssert(stderr.contains("Sample.raiseSignal"))
+    }
+
+    func testSIGSEGV() throws {
+        #if !os(Linux)
+        try XCTSkipIf(true, "test is only supported on Linux")
+        #endif
+
+        let stderr = try runSample(reason: "SIGSEGV")
+        print(stderr)
+
+        XCTAssert(stderr.contains("Received signal \(SIGSEGV). Backtrace:"))
+        XCTAssert(stderr.contains("Sample.raiseSignal"))
+    }
+
+    func testSIGBUS() throws {
+        #if !os(Linux)
+        try XCTSkipIf(true, "test is only supported on Linux")
+        #endif
+
+        let stderr = try runSample(reason: "SIGBUS")
+        print(stderr)
+
+        XCTAssert(stderr.contains("Received signal \(SIGBUS). Backtrace:"))
+        XCTAssert(stderr.contains("Sample.raiseSignal"))
+    }
+
+    func testSIGFPE() throws {
+        #if !os(Linux)
+        try XCTSkipIf(true, "test is only supported on Linux")
+        #endif
+
+        let stderr = try runSample(reason: "SIGFPE")
+        print(stderr)
+
+        XCTAssert(stderr.contains("Received signal \(SIGFPE). Backtrace:"))
+        XCTAssert(stderr.contains("Sample.raiseSignal"))
+    }
+
+    func runSample(reason: String) throws -> String {
         let pipe = Pipe()
         let process = Process()
         process.executableURL = URL(fileURLWithPath: "/usr/bin/swift")
-        process.arguments = ["run", "Sample", expectedError]
+        process.arguments = ["run", "Sample", reason]
         process.standardError = pipe
-        XCTAssertNoThrow(try process.run())
-        if process.isRunning {
-            process.waitUntilExit()
-        }
-        let stderr = String(data: pipe.fileHandleForReading.readDataToEndOfFile(), encoding: .utf8) ?? ""
-        print(stderr)
-        XCTAssert(stderr.contains("Current stack trace:"), "expected stanard error to include backtrace")
-        XCTAssert(stderr.contains("Fatal error: \(expectedError)"), "expected stanard error to include error information")
-        #endif
+        try process.run()
+        process.waitUntilExit()
+        return String(data: pipe.fileHandleForReading.readDataToEndOfFile(), encoding: .utf8) ?? ""
     }
 }

docker/Dockerfile

@@ -17,8 +17,10 @@ RUN apt-get update && apt-get install -y wget
 RUN apt-get update && apt-get install -y lsof dnsutils netcat-openbsd net-tools curl jq # used by integration tests
 
 # ruby and jazzy for docs generation
-RUN apt-get update && apt-get install -y ruby ruby-dev libsqlite3-dev
-RUN if [ "${ubuntu_version}" != "xenial" ] ; then gem install jazzy --no-ri --no-rdoc ; fi
+RUN apt-get update && apt-get install -y ruby ruby-dev libsqlite3-dev build-essential
+# jazzy no longer works on older version of ubuntu as ruby is too old.
+RUN if [ "${ubuntu_version}" = "focal" ] ; then echo "gem: --no-document" > ~/.gemrc ; fi
+RUN if [ "${ubuntu_version}" = "focal" ] ; then gem install jazzy ; fi
 
 # tools
 RUN mkdir -p $HOME/.tools

docker/docker-compose.2004.54.yaml

@@ -0,0 +1,16 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:20.04-5.4
+    build:
+      args:
+        ubuntu_version: "focal"
+        swift_version: "5.4"
+
+  test:
+    image: swift-linux-backtrace:20.04-5.4
+
+  shell:
+    image: swift-linux-backtrace:20.04-5.4

docker/docker-compose.2004.55.yaml

@@ -0,0 +1,16 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:20.04-5.5
+    build:
+      args:
+        ubuntu_version: "focal"
+        swift_version: "5.5"
+
+  test:
+    image: swift-linux-backtrace:20.04-5.5
+
+  shell:
+    image: swift-linux-backtrace:20.04-5.5

docker/docker-compose.2004.56.yaml

@@ -0,0 +1,16 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:20.04-5.6
+    build:
+      args:
+        ubuntu_version: "focal"
+        swift_version: "5.6"
+
+  test:
+    image: swift-linux-backtrace:20.04-5.6
+
+  shell:
+    image: swift-linux-backtrace:20.04-5.6

docker/docker-compose.2004.57.yaml

@@ -0,0 +1,15 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:20.04-5.7
+    build:
+      args:
+        base_image: "swiftlang/swift:nightly-main-focal"
+
+  test:
+    image: swift-linux-backtrace:20.04-5.7
+
+  shell:
+    image: swift-linux-backtrace:20.04-5.7

docker/docker-compose.2004.main.yaml

@@ -0,0 +1,15 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:20.04-main
+    build:
+      args:
+        base_image: "swiftlang/swift:nightly-main-focal"
+
+  test:
+    image: swift-linux-backtrace:20.04-main
+
+  shell:
+    image: swift-linux-backtrace:20.04-main

docker/docker-compose.yaml

@@ -34,4 +34,4 @@ services:
 
   shell:
     <<: *common
-    entrypoint: /bin/bash
+    entrypoint: /bin/bash -l

scripts/vendor-libbacktrace.sh

@@ -63,12 +63,15 @@ done
 
 EXCLUDES=(
 '*test*'
-'alloc.c'
 'nounwind.c'
 'pecoff.c'
 'read.c'
 'unknown.c'
 'xcoff.c'
+'macho.c'
+'alloc.c'
+'allocfail.c'
+'instrumented_alloc.c'
 )
 
 for exclude in "${EXCLUDES[@]}"