diff options
author | Alan Wu <XrXr@users.noreply.github.com> | 2021-12-01 14:15:23 -0500 |
---|---|---|
committer | Alan Wu <XrXr@users.noreply.github.com> | 2021-12-03 20:02:25 -0500 |
commit | f41b4d44f95978dfa97af04af00055dc3fbf7978 (patch) | |
tree | 744a3d5e2d8f1ef0b3a4ab00a7cd99df0353f6b8 /yjit_iface.c | |
parent | 3be067234f156d75e6143cca5037df7eef1bd112 (diff) |
YJIT: Bounds check every byte in the assembler
Previously, YJIT assumed that basic blocks never consume more than
1 KiB of memory. This assumption does not hold for long Ruby methods
such as the one in the following:
```ruby
eval(<<RUBY)
def set_local_a_lot
#{'_=0;'*0x40000}
end
RUBY
set_local_a_lot
```
For low `--yjit-exec-mem-size` values, one basic block could exhaust the
entire buffer.
Introduce a new field `codeblock_t::dropped_bytes` that the assembler
sets whenever it runs out of space. Check this field in
gen_single_block() to respond to out of memory situations and other
error conditions. This design avoids making the control flow graph of
existing code generation functions more complex.
Use POSIX shell in misc/test_yjit_asm.sh since bash is expanding
`0%/*/*` differently.
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
Notes
Notes:
Merged: https://github.com/ruby/ruby/pull/5209
Diffstat (limited to 'yjit_iface.c')
-rw-r--r-- | yjit_iface.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/yjit_iface.c b/yjit_iface.c index 739d639ae6..5c9e024a5f 100644 --- a/yjit_iface.c +++ b/yjit_iface.c @@ -1150,7 +1150,7 @@ yjit_get_code_page(uint32_t cb_bytes_needed, uint32_t ocb_bytes_needed) code_page_t *new_code_page = rb_yjit_code_page_unwrap(yjit_cur_code_page); // Jump to the new code page - jmp_ptr(&code_page->cb, new_code_page->cb.mem_block); + jmp_ptr(&code_page->cb, cb_get_ptr(&new_code_page->cb, 0)); return yjit_cur_code_page; } |