From ee86de1f1a22c45548bc39916fcd2b72dd26ebca Mon Sep 17 00:00:00 2001 From: Damien George Date: Mon, 10 Apr 2017 16:02:56 +1000 Subject: py: Make sure that static emg-exc-buffer is aligned to size of mp_obj_t. This buffer is used to allocate objects temporarily, and such objects require that their underlying memory be correctly aligned for their data type. Aligning for mp_obj_t should be sufficient for emergency exceptions, but in general the memory buffer should aligned to the maximum alignment of the machine (eg on a 32-bit machine with mp_obj_t being 4 bytes, a double may not be correctly aligned). This patch fixes a bug for certain nan-boxing builds, where mp_obj_t is 8 bytes and must be aligned to 8 bytes (even though the machine is 32 bit). --- py/mpstate.h | 4 ++-- py/objexcept.c | 6 +++--- 2 files changed, 5 insertions(+), 5 deletions(-) (limited to 'py') diff --git a/py/mpstate.h b/py/mpstate.h index 0134dd8e88..2b8f29a6ae 100644 --- a/py/mpstate.h +++ b/py/mpstate.h @@ -120,8 +120,8 @@ typedef struct _mp_state_vm_t { // memory for exception arguments if we can't allocate RAM #if MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF #if MICROPY_EMERGENCY_EXCEPTION_BUF_SIZE > 0 - // statically allocated buf - byte mp_emergency_exception_buf[MICROPY_EMERGENCY_EXCEPTION_BUF_SIZE]; + // statically allocated buf (needs to be aligned to mp_obj_t) + mp_obj_t mp_emergency_exception_buf[MICROPY_EMERGENCY_EXCEPTION_BUF_SIZE / sizeof(mp_obj_t)]; #else // dynamically allocated buf byte *mp_emergency_exception_buf; diff --git a/py/objexcept.c b/py/objexcept.c index 1f1009ff78..dcc7800dca 100644 --- a/py/objexcept.c +++ b/py/objexcept.c @@ -348,7 +348,7 @@ mp_obj_t mp_obj_new_exception_msg_varg(const mp_obj_type_t *exc_type, const char tuple->items[0] = MP_OBJ_FROM_PTR(str); byte *str_data = (byte *)&str[1]; - uint max_len = MP_STATE_VM(mp_emergency_exception_buf) + mp_emergency_exception_buf_size + size_t max_len = (byte*)MP_STATE_VM(mp_emergency_exception_buf) + mp_emergency_exception_buf_size - str_data; vstr_t vstr; @@ -366,14 +366,14 @@ mp_obj_t mp_obj_new_exception_msg_varg(const mp_obj_type_t *exc_type, const char o->args = tuple; - uint offset = &str_data[str->len] - MP_STATE_VM(mp_emergency_exception_buf); + size_t offset = &str_data[str->len] - (byte*)MP_STATE_VM(mp_emergency_exception_buf); offset += sizeof(void *) - 1; offset &= ~(sizeof(void *) - 1); if ((mp_emergency_exception_buf_size - offset) > (sizeof(o->traceback_data[0]) * 3)) { // We have room to store some traceback. o->traceback_data = (size_t*)((byte *)MP_STATE_VM(mp_emergency_exception_buf) + offset); - o->traceback_alloc = (MP_STATE_VM(mp_emergency_exception_buf) + mp_emergency_exception_buf_size - (byte *)o->traceback_data) / sizeof(o->traceback_data[0]); + o->traceback_alloc = ((byte*)MP_STATE_VM(mp_emergency_exception_buf) + mp_emergency_exception_buf_size - (byte *)o->traceback_data) / sizeof(o->traceback_data[0]); o->traceback_len = 0; } } -- cgit v1.2.3