archive/ruby
1
0
Fork 0
mirror of https://github.com/ruby/ruby.git synced 2025-08-15 13:39:04 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 4

[wasm] Avoid malloc during longjmp

Browse source 
`longjmp` can be called to raise `NoMemoryError` or to trigger GC when
`malloc` fails to allocate memory in `ruby_xmalloc` family. In such
case, `malloc` call in `longjmp` will fail again, and Asyncify unwinding
operation corrupts the memory space by using the failed pointer as
Asyncify buffer. This commit uses statically allocated buffer to avoid
such situation.
This commit is contained in:
Yuta Saito 2023-11-22 16:08:53 +00:00
parent c1fc1a00ea
commit 0e59d91eed
1 changed files with 4 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

6
wasm/setjmp.c
View file

@ -101,7 +101,6 @@ _rb_wasm_setjmp_internal(rb_wasm_jmp_buf *env)
asyncify_stop_rewind();
RB_WASM_DEBUG_LOG(" JMP_BUF_STATE_RETURNING");
env->state = JMP_BUF_STATE_CAPTURED;
free(env->longjmp_buf_ptr);
_rb_wasm_active_jmpbuf = NULL;
return env->payload;
}
@ -119,7 +118,10 @@ _rb_wasm_longjmp(rb_wasm_jmp_buf* env, int value)
assert(value != 0);
env->state = JMP_BUF_STATE_RETURNING;
env->payload = value;
env->longjmp_buf_ptr = malloc(sizeof(struct __rb_wasm_asyncify_jmp_buf));
// Asyncify buffer built during unwinding for longjmp will not
// be used to rewind, so re-use static-variable.
static struct __rb_wasm_asyncify_jmp_buf tmp_longjmp_buf;
env->longjmp_buf_ptr = &tmp_longjmp_buf;
_rb_wasm_active_jmpbuf = env;
async_buf_init(env->longjmp_buf_ptr);
asyncify_start_unwind(env->longjmp_buf_ptr);