Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

fix(ruby): Fix crash when calculating Message hash values on 64-bit Windows #8565

Merged
merged 5 commits into from May 6, 2021
Merged

fix(ruby): Fix crash when calculating Message hash values on 64-bit Windows #8565

Changes from 2 commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
3e92117
fix(ruby): Fix crash when calculating Message hash values on 64-bit W…
dazuma May 5, 2021
9f72824
Better mapping for values outside the fixnum range
dazuma May 5, 2021
4257f55
Simpler downcasting of hash values
dazuma May 5, 2021
ee53fe8
Fix precedence
dazuma May 6, 2021
c9fb5e0
Fix bundle on Ruby 2.4
dazuma May 6, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
11 changes: 10 additions & 1 deletion ruby/ext/google/protobuf_c/message.c
View file
Open in desktop
Expand Up @@ -734,7 +734,16 @@ uint64_t Message_Hash(const upb_msg* msg, const upb_msgdef* m, uint64_t seed) {
*/
static VALUE Message_hash(VALUE _self) {
Message* self = ruby_to_Message(_self);
return INT2FIX(Message_Hash(self->msg, self->msgdef, 0));
uint64_t hash_value = Message_Hash(self->msg, self->msgdef, 0);
// Fixnum is restricted to signed long, so downcast if necessary.
long long_value = (long)hash_value;
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

What about:

  // RUBY_FIXNUM_MAX should be one less than a power of 2.
  assert(RUBY_FIXNUM_MAX & (RUBY_FIXNUM_MAX + 1) == 0);  
  return INT2FIX(hash_value & RUBY_FIXNUM_MAX);

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yeah, that works. It restricts hash values to positive, but I think 32-bit hashes are always positive for most Ruby objects anyway.

// Ensure we stay within the range allowed by Fixnum.
if (long_value < RUBY_FIXNUM_MIN) {
long_value = long_value + RUBY_FIXNUM_MAX + 1;
} else if (long_value > RUBY_FIXNUM_MAX) {
long_value = long_value - RUBY_FIXNUM_MAX - 1;
}
return INT2FIX(long_value);
}

/*
Expand Down