From: nagachika00@... Date: 2017-07-23T08:49:39+00:00 Subject: [ruby-core:82138] [Ruby trunk Bug#13595] rb_alloc_tmp_buffer2 broken when: elsize % sizeof(VALUE) == 0 Issue #13595 has been updated by nagachika (Tomoyuki Chikanaga). Backport changed from 2.2: DONTNEED, 2.3: DONTNEED, 2.4: REQUIRED to 2.2: DONTNEED, 2.3: DONTNEED, 2.4: DONE ruby_2_4 r59408 merged revision(s) 58902. ---------------------------------------- Bug #13595: rb_alloc_tmp_buffer2 broken when: elsize % sizeof(VALUE) == 0 https://bugs.ruby-lang.org/issues/13595#change-65896 * Author: normalperson (Eric Wong) * Status: Closed * Priority: Normal * Assignee: naruse (Yui NARUSE) * Target version: * ruby -v: * Backport: 2.2: DONTNEED, 2.3: DONTNEED, 2.4: DONE ---------------------------------------- Here is the function in full as of current trunk (r58863): ~~~c static inline void * rb_alloc_tmp_buffer2(volatile VALUE *store, long count, size_t elsize) { size_t cnt = (size_t)count; if (elsize % sizeof(VALUE) == 0) { if (RB_UNLIKELY(cnt > LONG_MAX / sizeof(VALUE))) { ruby_malloc_size_overflow(cnt, elsize); } } else { size_t size, max = LONG_MAX - sizeof(VALUE) + 1; if (RB_UNLIKELY(rb_mul_size_overflow(cnt, elsize, max, &size))) { ruby_malloc_size_overflow(cnt, elsize); } cnt = (size + sizeof(VALUE) - 1) / sizeof(VALUE); } return rb_alloc_tmp_buffer_with_count(store, cnt * sizeof(VALUE), cnt); } ~~~ Notice that elsize is completely ignored in the top branch when "`(elsize % sizeof(VALUE) == 0)`" is true; this gives me problems when attempting to use `ALLOCV_N`. I am terrible at arithmetic and this function is too complicated for me, so I'll let naruse or someone else fix this. But please do. Thanks -- https://bugs.ruby-lang.org/ Unsubscribe: