Along with removing mrb_state first argument from the function. From
mruby 3.2, this function is *not* the default function, but the entry
point that can be redefined for the application. The function in
`src/allocf.c` is the default *implementation* (using malloc / realloc /
free) of the function.
Calling `mrb_gc_unregistor()` from `mrb_data_type::dfree` caused a use-after-free deep inside `mrb_close()`.
The impetus to investigate was <https://github.com/mruby/mruby/pull/6342#pullrequestreview-2292747530>.
Currently, when `mrb_close()` is called, all objects are destroyed first.
The process is done heap page by heap page, and when all objects belonging to a heap page are destroyed, the heap page is released.
If the next heap page contains `RData` objects, the `mrb_gc_unregistor()` function may be called from the `mrb_data_type::dfree` function.
At this time, the `mrb_gc_unregistor()` function gets an array object from a Ruby global variable.
If the array object belongs to a freed heap page, use-after-free is established by referencing this array object.
About the fixes.
First of all, there is the fact that the `mrb_gv_get()` function returns `nil` if `mrb->globals` is `NULL`.
Therefore, before destroying all objects, free `mrb->globals` and set `mrb->globals` to `NULL` at the same time.
Now the `mrb_gv_get()` function will return `nil` to the calling `mrb_gc_unregistor()` function and `mrb_gc_unregistor()` will do nothing more.
ref. https://github.com/mruby/mruby/issues/4618
Internal functions can only be called from within the library.
Functions listed in `mruby/internal.h` can be called from:
* core (src/*.c)
* gems (mrbgems/**/*.c)
But not from the application linked with `libmruby`.
`state.c` makes a prototype declaration for the private
`mrb_protect_atexit` which is defined in `error.c`. `error.c` defines
this function with a void return type, but `state.c` defines the
prototype with an `int` return type.
This mismatch prevents mruby from compiling on stricter compilers like
emscripten.
Add new pool value type `IREP_TT_BIGINT` and generate integer overflow
error in the VM. In the future, `mruby` will support `Bignum` for
integers bigger than `mrb_int` (probably using `mpz`).
When a global jump occurs, look at the catch handler table to determine where to jump.
In that case, `pc` already shows the following instruction, but since the table shows `begin_offset ... end_offset`, the comparison is done with `begin_offset < pc && pc <= end_offset`.
If there is a corresponding handler, move `pc` to `handler.target_offset` and continue running the VM.
When a global jump across `ensure` is made by `return`, `break`, `next`, `redo` and `retry`, the extended `RBreak` object saves and restores the C-level execution position.
This extended `RBreak` can have tag information, which makes it a pseudo coroutine (the "tag" mimics CRuby).
The implementation of pseudo coroutines by `RBreak` is summarized by `CHECKPOINT_RESTORE ... CHECKPOINT_MAIN ... CHECKPOINT_END` and `throw_tagged_break` / `unwind_ensure` macros.
The restart of processing is branched by `RBREAK_TAG_FOREACH(DISPATCH_CHECKPOINTS)`.
- Not only `rescue` blocks but also `ensure` blocks are now sandwiched between `OP_EXCEPT` and `OP_RAISEIF`.
- Remove the function `ecall()`.
It is no longer necessary to re-enter the VM to perform an "ensure block".
This will resolves#1888.
- Added instruction `OP_JUW` (Jump while UnWind).
It jumps unconditionally like `OP_JMP`, but searches the catch handler table and executes the ensure block.
Since it searches the catch handler table, it is much heavier than `OP_JMP`.
Changes:
- `pool format is completely replaced
- supported types: `STR`, `INT32`, `INT64`, `FLOAT`
- `FLOAT` may be replaced by binary representation in the future
- insert `NUL` after string literals in `mrb` files
- `irep->pool` no longer store values in `mrb_value`
- instead it stores in `mrb_pool_value`
- less allocation
- `mrb_irep` can be stored in ROM
commit 2d7d545c4c4bfce7fdcbcbe9baaeb437915742f0
Merge: 625a1249 b178914b
Author: Yukihiro "Matz" Matsumoto <matz@ruby.or.jp>
Date: Fri Jun 5 14:35:13 2020 +0900
Merge branch 'fix-mrb_open-with-nomem' of https://github.com/dearblue/mruby into dearblue-fix-mrb_open-with-nomem
commit b178914b11
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sat Jan 19 22:22:44 2019 +0900
Fix invalid pointer free inside other heap's block
1. `e = mrb_obj_alloc(...)`
2. `e->stack = mrb->c->stack` (`mrb->c->stack` is anywhere in the range `stbase...stend`)
3. And raised exception by `mrb_malloc()`!
4. `mrb_free(e->stack)` by GC part (wrong free)
commit 52e3d5d858
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sat Jan 19 21:55:36 2019 +0900
Fix memory leak for temporary symbols when out of memory
commit 4c5499b88e
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sun Jan 20 11:42:07 2019 +0900
Fix uninitialized pointer dereference for debug section
commit 8e993167de
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sun Jan 20 11:41:09 2019 +0900
Fix memory leak for temporary filenames when out of memory
commit 8b422577e6
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sun Jan 20 10:57:51 2019 +0900
Fix memory leak for irep when out of memory
commit 6b35ebf49a
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sun Jan 20 10:55:50 2019 +0900
Fix uninitialized pointer dereference when do not finished initializing irep
commit 2531f2631e
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sun Jan 20 10:48:15 2019 +0900
Fix NULL pointer dereference when do not finished initializing irep
commit e2d6896eba
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sat Jan 19 12:54:19 2019 +0900
Fix memory leak for irep when out of memory by `mrb_proc_new()`
commit b6214ff8a0
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sat Jan 19 12:53:07 2019 +0900
Fix memory leak for `khash_t` in `kh_init_size()` when out of memory by `kh_alloc()`
commit 19162dd6c1
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sun Jan 20 02:15:07 2019 +0900
Fix memory leak for symbol string when out of memory in `kh_put()`
commit 15e67297ff
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sun Jan 20 02:12:24 2019 +0900
Fix keep wrong symbol index when out of memory
commit 3f8e2b3752
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sun Jan 20 02:08:13 2019 +0900
Fix keep wrong symbol capacity when out of memory
commit a3cfe755ab
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sat Jan 19 10:11:37 2019 +0900
Fix NULL pointer dereference `mrb->c` by `mark_context()`
commit d9c7b6be6e
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sun Jan 20 15:25:09 2019 +0900
Fix protect exception for print error message
commit 100642750e
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sun Jan 20 11:59:02 2019 +0900
Protect exception for mruby core initialization
commit 7a0418304e
Author: dearblue <dearblue@users.noreply.github.com>
Date: Fri Jan 18 20:38:27 2019 +0900
Fix memory leak for string object when out of memory
The `mrb_str_pool()` function has a path to call `malloc()` twice.
If occurs `NoMemoryError` exception in second `malloc()`,
first `malloc()` pointer is not freed.
commit fef1c152ce
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sat Jan 19 13:05:09 2019 +0900
Fix stack overflow when out of memory
As a result of this change, no backtrace information is set
for NoMemoryError (`mrb->nomem_err`).
Detailes:
When generating a backtrace, called `mrb_intern_lit()`,
`mrb_str_new_cstr()` and `mrb_obj_iv_set()` function with
`exc_debug_info()` function in `src/error.c`.
If a `NoMemoryError` exception occurs at this time,
the `exc_debug_info()` function will be called again,
and in the same way `NoMemoryError` exception raised will result
in an infinite loop to occurs stack overflow (and SIGSEGV).
commit da7d7f881b
Author: dearblue <dearblue@users.noreply.github.com>
Date: Sun Jan 20 12:00:38 2019 +0900
Fix NULL pointer dereference `mrb->nomem_err` when not initialized
Add internal functions (not `static`):
* `mrb_raise_nomemory()`
* `mrb_core_init_abort()`
When I found this function, I expected it to behave the same as the
`alloca(3)` function, but it is accually the `mrb_alloca()` function
does not free the heap until the `mrb_close()` function is called.
Also, even if it is deleted, it can be replaced with the combination
of the `MRB_TT_DATA` object and the `mrb_gv_set()` function if it is
sure necessary.
Instead of `irep` links, we added a `upper` link to `struct RProc`.
To make a space for the `upper` link, we moved `target_class` reference.
If a `Proc` does not have `env`, `target_class` is saved in an `union`
shared with `env` (if a `Proc` has env, you can tell it by `MRB_PROC_ENV_P()).
Otherwise `target_class` is referenced from `env->c`. We removed links
in `env` as well.
This change removes 2 members from `mrb_irep` struct, thus saving 2
words per method/proc/block. This also fixes potential memory leaks
due to the circular references caused by a link from `mrb_irep`.
Instead of `irep -> proc` chain, we use `irep -> irep` chain to
avoid GC bugs like #3804. We added `target_class` reference to
`mrb_irep` struct. That means one more word consumption per `irep`.
Instead of preserving a backtrace in `mrb_state`, `mrb_exc_set`
keeps packed backtrace in an exception object. `#backtrace` unpacks
it to an array of strings.
Yukihiro "Matz" Matsumoto