diff options
author | Emilie Feral <emilie.feral@numworks.com> | 2021-12-27 15:39:34 +0100 |
---|---|---|
committer | Damien George <damien@micropython.org> | 2022-01-06 13:00:43 +1100 |
commit | 58b56b91c454f4e1c04ca1cf58e35809caf979de (patch) | |
tree | d834196df3c8559f475a63581da97ff96b31e369 /py/qstr.c | |
parent | 01953f2964e4e26b9bbf70d19d1e199ed2cf1a89 (diff) |
py/qstr: Reset mpstate.qstr_last_chunk before raising an error.
The qstr_last_chunk is not collected by the garbage collector. This relies
on the assertion that qstr_pool_t also references the qstr_last_chunk. If
an exception is raised while allocating the qstr_pool_t, qstr_last_chunk
has to be invalidated not to become a dangling reference at the next
garbage collection.
Signed-off-by: Emilie Feral <emilie.feral@numworks.com>
Diffstat (limited to 'py/qstr.c')
-rw-r--r-- | py/qstr.c | 6 |
1 files changed, 6 insertions, 0 deletions
@@ -153,6 +153,12 @@ STATIC qstr qstr_add(const byte *q_ptr) { #endif qstr_pool_t *pool = m_new_obj_var_maybe(qstr_pool_t, const char *, new_alloc); if (pool == NULL) { + // Keep qstr_last_chunk consistent with qstr_pool_t: qstr_last_chunk is not scanned + // at garbage collection since it's reachable from a qstr_pool_t. And the caller of + // this function expects q_ptr to be stored in a qstr_pool_t so it can be reached + // by the collector. If qstr_pool_t allocation failed, qstr_last_chunk needs to be + // NULL'd. Otherwise it may become a dangling pointer at the next garbage collection. + MP_STATE_VM(qstr_last_chunk) = NULL; QSTR_EXIT(); m_malloc_fail(new_alloc); } |