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author | Yuta Saito <kateinoigakukun@gmail.com> | 2022-09-24 03:36:04 +0900 |
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committer | usa <usa@garbagecollect.jp> | 2022-10-01 15:58:54 +0900 |
commit | 022aefb4500bfb8f6812a5e729d06f3f2fe21cea (patch) | |
tree | b65aa08813aeff1425ce6c6c15b35bd01dc4c1ab | |
parent | 99735a8b296cfda272f8dce6bd07af50cd97034e (diff) | |
download | ruby-022aefb4500bfb8f6812a5e729d06f3f2fe21cea.tar.gz |
Initialize Objective-C classes before fork() for macOS 13
Since macOS 13, CFString family API used in
`rb_str_append_normalized_ospath` may internally use Objective-C classes
(`NSTaggedPointerString` and `NSPlaceholderMutableString`) for small strings.
On the other hand, Objective-C classes should not be used for the first
time in a `fork()`'ed but not `exec()`'ed process. Violations for this rule
can result deadlock during class initialization, so Objective-C runtime
conservatively crashes on such cases by default.
Therefore, we need to use CFString API to initialize Objective-C classes
used internally *before* `fork()`.
For more details, see https://bugs.ruby-lang.org/issues/18912
-rw-r--r-- | file.c | 44 |
1 files changed, 44 insertions, 0 deletions
@@ -253,6 +253,46 @@ rb_str_encode_ospath(VALUE path) #ifdef __APPLE__ # define NORMALIZE_UTF8PATH 1 + +# ifdef HAVE_WORKING_FORK +static void +rb_CFString_class_initialize_before_fork(void) +{ + /* + * Since macOS 13, CFString family API used in + * rb_str_append_normalized_ospath may internally use Objective-C classes + * (NSTaggedPointerString and NSPlaceholderMutableString) for small strings. + * + * On the other hand, Objective-C classes should not be used for the first + * time in a fork()'ed but not exec()'ed process. Violations for this rule + * can result deadlock during class initialization, so Objective-C runtime + * conservatively crashes on such cases by default. + * + * Therefore, we need to use CFString API to initialize Objective-C classes + * used internally *before* fork(). + * + * For future changes, please note that this initialization process cannot + * be done in ctor because NSTaggedPointerString in CoreFoundation is enabled + * after CFStringInitializeTaggedStrings(), which is called during loading + * Objective-C runtime after ctor. + * For more details, see https://bugs.ruby-lang.org/issues/18912 + */ + + /* Enough small but non-empty ASCII string to fit in NSTaggedPointerString. */ + const char small_str[] = "/"; + long len = sizeof(small_str) - 1; + + const CFAllocatorRef alloc = kCFAllocatorDefault; + CFStringRef s = CFStringCreateWithBytesNoCopy(alloc, + (const UInt8 *)small_str, + len, kCFStringEncodingUTF8, + FALSE, kCFAllocatorNull); + CFMutableStringRef m = CFStringCreateMutableCopy(alloc, len, s); + CFRelease(m); + CFRelease(s); +} +# endif + static VALUE rb_str_append_normalized_ospath(VALUE str, const char *ptr, long len) { @@ -6455,6 +6495,10 @@ const char ruby_null_device[] = void Init_File(void) { +#if defined(__APPLE__) && defined(HAVE_WORKING_FORK) + rb_CFString_class_initialize_before_fork(); +#endif + VALUE separator; rb_mFileTest = rb_define_module("FileTest"); |