Skip to content

gc.c: Ensure a gap of one byte before the finaliser table. #5245

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Aug 27, 2021
Merged

gc.c: Ensure a gap of one byte before the finaliser table. #5245

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
15133cb
gc.c: Avoid valgrind false positives.
jepler Aug 27, 2021
5a162eb
gc.c: Ensure a gap of one byte before the finaliser table.
jepler Aug 27, 2021
955c027
Merge remote-tracking branch 'origin/main' into pool-fix-circuitpython
jepler Aug 27, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 11 additions & 2 deletions py/gc.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,10 @@
#include "py/gc.h"
#include "py/runtime.h"

#if MICROPY_DEBUG_VALGRIND
#include <valgrind/memcheck.h>
#endif

#include "supervisor/shared/safe_mode.h"

#if CIRCUITPY_MEMORYMONITOR
Expand Down Expand Up @@ -126,7 +130,7 @@ void gc_init(void *start, void *end) {
// => T = A * (1 + BLOCKS_PER_ATB / BLOCKS_PER_FTB + BLOCKS_PER_ATB * BYTES_PER_BLOCK)
size_t total_byte_len = (byte *)end - (byte *)start;
#if MICROPY_ENABLE_FINALISER
MP_STATE_MEM(gc_alloc_table_byte_len) = total_byte_len * MP_BITS_PER_BYTE / (MP_BITS_PER_BYTE + MP_BITS_PER_BYTE * BLOCKS_PER_ATB / BLOCKS_PER_FTB + MP_BITS_PER_BYTE * BLOCKS_PER_ATB * BYTES_PER_BLOCK);
MP_STATE_MEM(gc_alloc_table_byte_len) = (total_byte_len - 1) * MP_BITS_PER_BYTE / (MP_BITS_PER_BYTE + MP_BITS_PER_BYTE * BLOCKS_PER_ATB / BLOCKS_PER_FTB + MP_BITS_PER_BYTE * BLOCKS_PER_ATB * BYTES_PER_BLOCK);
#else
MP_STATE_MEM(gc_alloc_table_byte_len) = total_byte_len / (1 + MP_BITS_PER_BYTE / 2 * BYTES_PER_BLOCK);
#endif
Expand All @@ -135,7 +139,7 @@ void gc_init(void *start, void *end) {

#if MICROPY_ENABLE_FINALISER
size_t gc_finaliser_table_byte_len = (MP_STATE_MEM(gc_alloc_table_byte_len) * BLOCKS_PER_ATB + BLOCKS_PER_FTB - 1) / BLOCKS_PER_FTB;
MP_STATE_MEM(gc_finaliser_table_start) = MP_STATE_MEM(gc_alloc_table_start) + MP_STATE_MEM(gc_alloc_table_byte_len);
MP_STATE_MEM(gc_finaliser_table_start) = MP_STATE_MEM(gc_alloc_table_start) + MP_STATE_MEM(gc_alloc_table_byte_len) + 1;
#endif

size_t gc_pool_block_len = MP_STATE_MEM(gc_alloc_table_byte_len) * BLOCKS_PER_ATB;
Expand Down Expand Up @@ -391,6 +395,11 @@ void gc_collect_ptr(void *ptr) {
__attribute__((no_sanitize_address))
#endif
static void *gc_get_ptr(void **ptrs, int i) {
#if MICROPY_DEBUG_VALGRIND
if (!VALGRIND_CHECK_MEM_IS_ADDRESSABLE(&ptrs[i], sizeof(*ptrs))) {
return NULL;
}
#endif
return ptrs[i];
}

Expand Down
5 changes: 5 additions & 0 deletions py/mpconfig.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -486,6 +486,11 @@
#define MICROPY_DEBUG_VM_STACK_OVERFLOW (0)
#endif

// Whether to enable extra instrumentation for valgrind
#ifndef MICROPY_DEBUG_VALGRIND
#define MICROPY_DEBUG_VALGRIND (0)
#endif

/*****************************************************************************/
/* Optimisations */

Expand Down