[gtk/ebassi/secure-buffer: 1/6] Import egg-secure-memory allocator from gcr
- From: Emmanuele Bassi <ebassi src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gtk/ebassi/secure-buffer: 1/6] Import egg-secure-memory allocator from gcr
- Date: Tue, 8 Sep 2020 22:50:44 +0000 (UTC)
commit 31a75745443a4e07aa55b743aa6ccf99cc473f2f
Author: Emmanuele Bassi <ebassi gnome org>
Date: Tue Sep 8 17:40:32 2020 +0100
Import egg-secure-memory allocator from gcr
We can re-use the code inside gcr, as we know that it's working, tested,
and license compatible.
gtk/gtksecurememory.c | 1434 ++++++++++++++++++++++++++++++++++++++++++
gtk/gtksecurememoryprivate.h | 95 +++
gtk/meson.build | 1 +
3 files changed, 1530 insertions(+)
---
diff --git a/gtk/gtksecurememory.c b/gtk/gtksecurememory.c
new file mode 100644
index 0000000000..55db84398b
--- /dev/null
+++ b/gtk/gtksecurememory.c
@@ -0,0 +1,1434 @@
+/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */
+/* gtksecurememory.c - API for allocating memory that is non-pageable
+
+ Copyright 2007 Stefan Walter
+ Copyright 2020 GNOME Foundation
+
+ SPDX-License-Identifier: LGPL-2.0-or-later
+
+ The Gnome Keyring Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The Gnome Keyring Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the Gnome Library; see the file COPYING.LIB. If not,
+ see <http://www.gnu.org/licenses/>.
+
+ Author: Stef Walter <stef memberwebs com>
+*/
+
+/*
+ * IMPORTANT: This is pure vanila standard C, no glib. We need this
+ * because certain consumers of this protocol need to be built
+ * without linking in any special libraries. ie: the PKCS#11 module.
+ */
+
+#include "config.h"
+
+#include "gtksecurememoryprivate.h"
+
+#include <sys/types.h>
+
+#if defined(HAVE_MLOCK)
+#include <sys/mman.h>
+#endif
+
+#include <stddef.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+#include <assert.h>
+
+#ifdef WITH_VALGRIND
+#include <valgrind/valgrind.h>
+#include <valgrind/memcheck.h>
+#endif
+
+#define DEBUG_SECURE_MEMORY 0
+
+#if DEBUG_SECURE_MEMORY
+#define DEBUG_ALLOC(msg, n) fprintf(stderr, "%s %lu bytes\n", msg, n);
+#else
+#define DEBUG_ALLOC(msg, n)
+#endif
+
+#define DEFAULT_BLOCK_SIZE 16384
+
+#define DO_LOCK() \
+ GTK_SECURE_GLOBALS.lock ();
+
+#define DO_UNLOCK() \
+ GTK_SECURE_GLOBALS.unlock ();
+
+typedef struct {
+ void (* lock) (void);
+ void (* unlock) (void);
+ void * (* fallback_alloc) (void *pointer,
+ size_t length);
+ void (* fallback_free) (void *pointer);
+ void * pool_data;
+ const char * pool_version;
+} GtkSecureGlob;
+
+#include <glib.h>
+
+#define GTK_SECURE_POOL_VER_STR "1.0"
+
+static int show_warning = 1;
+static int gtk_secure_warnings = 1;
+static GMutex memory_mutex;
+
+static void
+gtk_memory_lock (void)
+{
+ g_mutex_lock (&memory_mutex);
+}
+
+static void
+gtk_memory_unlock (void)
+{
+ g_mutex_unlock (&memory_mutex);
+}
+
+static GtkSecureGlob GTK_SECURE_GLOBALS = {
+ .lock = gtk_memory_lock,
+ .unlock = gtk_memory_unlock,
+ .fallback_alloc = g_realloc,
+ .fallback_free = g_free,
+ .pool_data = NULL,
+ .pool_version = GTK_SECURE_POOL_VER_STR,
+};
+
+/*
+ * We allocate all memory in units of sizeof(void*). This
+ * is our definition of 'word'.
+ */
+typedef void* word_t;
+
+/* The amount of extra words we can allocate */
+#define WASTE 4
+
+/*
+ * Track allocated memory or a free block. This structure is not stored
+ * in the secure memory area. It is allocated from a pool of other
+ * memory. See meta_pool_xxx ().
+ */
+typedef struct _Cell {
+ word_t *words; /* Pointer to secure memory */
+ size_t n_words; /* Amount of secure memory in words */
+ size_t requested; /* Amount actually requested by app, in bytes, 0 if unused */
+ const char *tag; /* Tag which describes the allocation */
+ struct _Cell *next; /* Next in memory ring */
+ struct _Cell *prev; /* Previous in memory ring */
+} Cell;
+
+/*
+ * A block of secure memory. This structure is the header in that block.
+ */
+typedef struct _Block {
+ word_t *words; /* Actual memory hangs off here */
+ size_t n_words; /* Number of words in block */
+ size_t n_used; /* Number of used allocations */
+ struct _Cell* used_cells; /* Ring of used allocations */
+ struct _Cell* unused_cells; /* Ring of unused allocations */
+ struct _Block *next; /* Next block in list */
+} Block;
+
+/* -----------------------------------------------------------------------------
+ * UNUSED STACK
+ */
+
+static inline void
+unused_push (void **stack, void *ptr)
+{
+ g_assert (ptr);
+ g_assert (stack);
+ *((void**)ptr) = *stack;
+ *stack = ptr;
+}
+
+static inline void*
+unused_pop (void **stack)
+{
+ void *ptr;
+ g_assert (stack);
+ ptr = *stack;
+ *stack = *(void**)ptr;
+ return ptr;
+
+}
+
+static inline void*
+unused_peek (void **stack)
+{
+ g_assert (stack);
+ return *stack;
+}
+
+/* -----------------------------------------------------------------------------
+ * POOL META DATA ALLOCATION
+ *
+ * A pool for memory meta data. We allocate fixed size blocks. There are actually
+ * two different structures stored in this pool: Cell and Block. Cell is allocated
+ * way more often, and is bigger so we just allocate that size for both.
+ */
+
+/* Pool allocates this data type */
+typedef union _Item {
+ Cell cell;
+ Block block;
+} Item;
+
+typedef struct _Pool {
+ struct _Pool *next; /* Next pool in list */
+ size_t length; /* Length in bytes of the pool */
+ size_t used; /* Number of cells used in pool */
+ void *unused; /* Unused stack of unused stuff */
+ size_t n_items; /* Total number of items in pool */
+ Item items[1]; /* Actual items hang off here */
+} Pool;
+
+static int
+check_pool_version (void)
+{
+ if (GTK_SECURE_GLOBALS.pool_version == NULL ||
+ strcmp (GTK_SECURE_GLOBALS.pool_version, GTK_SECURE_POOL_VER_STR) != 0) {
+ return 0;
+ }
+
+ return 1;
+}
+
+static void *
+pool_alloc (void)
+{
+ if (!check_pool_version ()) {
+ if (show_warning && gtk_secure_warnings)
+ fprintf (stderr, "the secure memory pool version does not match the code '%s' !=
'%s'\n",
+ GTK_SECURE_GLOBALS.pool_version ? GTK_SECURE_GLOBALS.pool_version : "(null)",
+ GTK_SECURE_POOL_VER_STR);
+ show_warning = 0;
+ return NULL;
+ }
+
+#ifdef HAVE_MMAP
+ /* A pool with an available item */
+ Pool *pool = NULL;
+
+ for (pool = GTK_SECURE_GLOBALS.pool_data; pool != NULL; pool = pool->next) {
+ if (unused_peek (&pool->unused))
+ break;
+ }
+
+ void *item = NULL;
+
+ /* Create a new pool */
+ if (pool == NULL) {
+ size_t len = getpagesize () * 2;
+ void *pages = mmap (0, len, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
+ if (pages == MAP_FAILED)
+ return NULL;
+
+ /* Fill in the block header, and inlude in block list */
+ pool = pages;
+ pool->next = GTK_SECURE_GLOBALS.pool_data;
+ GTK_SECURE_GLOBALS.pool_data = pool;
+ pool->length = len;
+ pool->used = 0;
+ pool->unused = NULL;
+
+ /* Fill block with unused items */
+ pool->n_items = (len - sizeof (Pool)) / sizeof (Item);
+ for (size_t i = 0; i < pool->n_items; ++i)
+ unused_push (&pool->unused, pool->items + i);
+
+#ifdef WITH_VALGRIND
+ VALGRIND_CREATE_MEMPOOL(pool, 0, 0);
+#endif
+ }
+
+ ++pool->used;
+ g_assert (unused_peek (&pool->unused));
+ item = unused_pop (&pool->unused);
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MEMPOOL_ALLOC (pool, item, sizeof (Item));
+#endif
+
+ return memset (item, 0, sizeof (Item));
+#else /* HAVE_MMAP */
+ return NULL;
+#endif
+}
+
+static void
+pool_free (void* item)
+{
+#ifdef HAVE_MMAP
+ Pool *pool, **at;
+ char *ptr, *beg, *end;
+
+ ptr = item;
+
+ /* Find which block this one belongs to */
+ for (at = (Pool **)>K_SECURE_GLOBALS.pool_data, pool = *at;
+ pool != NULL; at = &pool->next, pool = *at) {
+ beg = (char*)pool->items;
+ end = (char*)pool + pool->length - sizeof (Item);
+ if (ptr >= beg && ptr <= end) {
+ g_assert ((ptr - beg) % sizeof (Item) == 0);
+ break;
+ }
+ }
+
+ /* Otherwise invalid meta */
+ g_assert (at);
+ g_assert (pool);
+ g_assert (pool->used > 0);
+
+ /* No more meta cells used in this block, remove from list, destroy */
+ if (pool->used == 1) {
+ *at = pool->next;
+
+#ifdef WITH_VALGRIND
+ VALGRIND_DESTROY_MEMPOOL (pool);
+#endif
+
+ munmap (pool, pool->length);
+ return;
+ }
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MEMPOOL_FREE (pool, item);
+ VALGRIND_MAKE_MEM_UNDEFINED (item, sizeof (Item));
+#endif
+
+ --pool->used;
+ memset (item, 0xCD, sizeof (Item));
+ unused_push (&pool->unused, item);
+#endif /* HAVE_MMAP */
+}
+
+#ifndef G_DISABLE_ASSERT
+
+static int
+pool_valid (void* item)
+{
+ Pool *pool;
+ char *ptr, *beg, *end;
+
+ ptr = item;
+
+ /* Find which block this one belongs to */
+ for (pool = GTK_SECURE_GLOBALS.pool_data; pool; pool = pool->next) {
+ beg = (char*)pool->items;
+ end = (char*)pool + pool->length - sizeof (Item);
+ if (ptr >= beg && ptr <= end)
+ return (pool->used && (ptr - beg) % sizeof (Item) == 0);
+ }
+
+ return 0;
+}
+
+#endif /* G_DISABLE_g_assert */
+
+/* -----------------------------------------------------------------------------
+ * SEC ALLOCATION
+ *
+ * Each memory cell begins and ends with a pointer to its metadata. These are also
+ * used as guards or red zones. Since they're treated as redzones by valgrind we
+ * have to jump through a few hoops before reading and/or writing them.
+ */
+
+static inline size_t
+sec_size_to_words (size_t length)
+{
+ return (length % sizeof (void*) ? 1 : 0) + (length / sizeof (void*));
+}
+
+static inline void
+sec_write_guards (Cell *cell)
+{
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_UNDEFINED (cell->words, sizeof (word_t));
+ VALGRIND_MAKE_MEM_UNDEFINED (cell->words + cell->n_words - 1, sizeof (word_t));
+#endif
+
+ ((void**)cell->words)[0] = (void*)cell;
+ ((void**)cell->words)[cell->n_words - 1] = (void*)cell;
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_NOACCESS (cell->words, sizeof (word_t));
+ VALGRIND_MAKE_MEM_NOACCESS (cell->words + cell->n_words - 1, sizeof (word_t));
+#endif
+}
+
+static inline void
+sec_check_guards (Cell *cell)
+{
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_DEFINED (cell->words, sizeof (word_t));
+ VALGRIND_MAKE_MEM_DEFINED (cell->words + cell->n_words - 1, sizeof (word_t));
+#endif
+
+ g_assert(((void**)cell->words)[0] == (void*)cell);
+ g_assert(((void**)cell->words)[cell->n_words - 1] == (void*)cell);
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_NOACCESS (cell->words, sizeof (word_t));
+ VALGRIND_MAKE_MEM_NOACCESS (cell->words + cell->n_words - 1, sizeof (word_t));
+#endif
+}
+
+static void
+sec_insert_cell_ring (Cell **ring, Cell *cell)
+{
+ g_assert (ring);
+ g_assert (cell);
+ g_assert (cell != *ring);
+ g_assert (cell->next == NULL);
+ g_assert (cell->prev == NULL);
+
+ /* Insert back into the mix of available memory */
+ if (*ring) {
+ cell->next = (*ring)->next;
+ cell->prev = *ring;
+ cell->next->prev = cell;
+ cell->prev->next = cell;
+ } else {
+ cell->next = cell;
+ cell->prev = cell;
+ }
+
+ *ring = cell;
+ g_assert (cell->next->prev == cell);
+ g_assert (cell->prev->next == cell);
+}
+
+static void
+sec_remove_cell_ring (Cell **ring, Cell *cell)
+{
+ g_assert (ring);
+ g_assert (*ring);
+ g_assert (cell->next);
+ g_assert (cell->prev);
+
+ g_assert (cell->next->prev == cell);
+ g_assert (cell->prev->next == cell);
+
+ if (cell == *ring) {
+ /* The last meta? */
+ if (cell->next == cell) {
+ g_assert (cell->prev == cell);
+ *ring = NULL;
+
+ /* Just pointing to this meta */
+ } else {
+ g_assert (cell->prev != cell);
+ *ring = cell->next;
+ }
+ }
+
+ cell->next->prev = cell->prev;
+ cell->prev->next = cell->next;
+ cell->next = cell->prev = NULL;
+
+ g_assert (*ring != cell);
+}
+
+static inline void*
+sec_cell_to_memory (Cell *cell)
+{
+ return cell->words + 1;
+}
+
+static inline int
+sec_is_valid_word (Block *block, word_t *word)
+{
+ return (word >= block->words && word < block->words + block->n_words);
+}
+
+static inline void
+sec_clear_undefined (void *memory,
+ size_t from,
+ size_t to)
+{
+ char *ptr = memory;
+ g_assert (from <= to);
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_UNDEFINED (ptr + from, to - from);
+#endif
+ memset (ptr + from, 0, to - from);
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_UNDEFINED (ptr + from, to - from);
+#endif
+}
+static inline void
+sec_clear_noaccess (void *memory, size_t from, size_t to)
+{
+ char *ptr = memory;
+ g_assert (from <= to);
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_UNDEFINED (ptr + from, to - from);
+#endif
+ memset (ptr + from, 0, to - from);
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_NOACCESS (ptr + from, to - from);
+#endif
+}
+
+static Cell*
+sec_neighbor_before (Block *block, Cell *cell)
+{
+ word_t *word;
+
+ g_assert (cell);
+ g_assert (block);
+
+ word = cell->words - 1;
+ if (!sec_is_valid_word (block, word))
+ return NULL;
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_DEFINED (word, sizeof (word_t));
+#endif
+
+ cell = *word;
+ sec_check_guards (cell);
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_NOACCESS (word, sizeof (word_t));
+#endif
+
+ return cell;
+}
+
+static Cell*
+sec_neighbor_after (Block *block, Cell *cell)
+{
+ word_t *word;
+
+ g_assert (cell);
+ g_assert (block);
+
+ word = cell->words + cell->n_words;
+ if (!sec_is_valid_word (block, word))
+ return NULL;
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_DEFINED (word, sizeof (word_t));
+#endif
+
+ cell = *word;
+ sec_check_guards (cell);
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_NOACCESS (word, sizeof (word_t));
+#endif
+
+ return cell;
+}
+
+static void*
+sec_alloc (Block *block,
+ const char *tag,
+ size_t length)
+{
+ Cell *cell, *other;
+ size_t n_words;
+ void *memory;
+
+ g_assert (block);
+ g_assert (length);
+ g_assert (tag);
+
+ if (!block->unused_cells)
+ return NULL;
+
+ /*
+ * Each memory allocation is aligned to a pointer size, and
+ * then, sandwidched between two pointers to its meta data.
+ * These pointers also act as guards.
+ *
+ * We allocate memory in units of sizeof (void*)
+ */
+
+ n_words = sec_size_to_words (length) + 2;
+
+ /* Look for a cell of at least our required size */
+ cell = block->unused_cells;
+ while (cell->n_words < n_words) {
+ cell = cell->next;
+ if (cell == block->unused_cells) {
+ cell = NULL;
+ break;
+ }
+ }
+
+ if (!cell)
+ return NULL;
+
+ g_assert (cell->tag == NULL);
+ g_assert (cell->requested == 0);
+ g_assert (cell->prev);
+ g_assert (cell->words);
+ sec_check_guards (cell);
+
+ /* Steal from the cell if it's too long */
+ if (cell->n_words > n_words + WASTE) {
+ other = pool_alloc ();
+ if (!other)
+ return NULL;
+ other->n_words = n_words;
+ other->words = cell->words;
+ cell->n_words -= n_words;
+ cell->words += n_words;
+
+ sec_write_guards (other);
+ sec_write_guards (cell);
+
+ cell = other;
+ }
+
+ if (cell->next)
+ sec_remove_cell_ring (&block->unused_cells, cell);
+
+ ++block->n_used;
+ cell->tag = tag;
+ cell->requested = length;
+ sec_insert_cell_ring (&block->used_cells, cell);
+ memory = sec_cell_to_memory (cell);
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_UNDEFINED (memory, length);
+#endif
+
+ return memset (memory, 0, length);
+}
+
+static void*
+sec_free (Block *block, void *memory)
+{
+ Cell *cell, *other;
+ word_t *word;
+
+ g_assert (block);
+ g_assert (memory);
+
+ word = memory;
+ --word;
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_DEFINED (word, sizeof (word_t));
+#endif
+
+ /* Lookup the meta for this memory block (using guard pointer) */
+ g_assert (sec_is_valid_word (block, word));
+ g_assert (pool_valid (*word));
+ cell = *word;
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_DEFINED (cell->words, cell->n_words * sizeof (word_t));
+#endif
+
+ sec_check_guards (cell);
+ sec_clear_noaccess (memory, 0, cell->requested);
+
+ sec_check_guards (cell);
+ g_assert (cell->requested > 0);
+ g_assert (cell->tag != NULL);
+
+ /* Remove from the used cell ring */
+ sec_remove_cell_ring (&block->used_cells, cell);
+
+ /* Find previous unallocated neighbor, and merge if possible */
+ other = sec_neighbor_before (block, cell);
+ if (other && other->requested == 0) {
+ g_assert (other->tag == NULL);
+ g_assert (other->next && other->prev);
+ other->n_words += cell->n_words;
+ sec_write_guards (other);
+ pool_free (cell);
+ cell = other;
+ }
+
+ /* Find next unallocated neighbor, and merge if possible */
+ other = sec_neighbor_after (block, cell);
+ if (other && other->requested == 0) {
+ g_assert (other->tag == NULL);
+ g_assert (other->next && other->prev);
+ other->n_words += cell->n_words;
+ other->words = cell->words;
+ if (cell->next)
+ sec_remove_cell_ring (&block->unused_cells, cell);
+ sec_write_guards (other);
+ pool_free (cell);
+ cell = other;
+ }
+
+ /* Add to the unused list if not already there */
+ if (!cell->next)
+ sec_insert_cell_ring (&block->unused_cells, cell);
+
+ cell->tag = NULL;
+ cell->requested = 0;
+ --block->n_used;
+ return NULL;
+}
+
+static void
+memcpy_with_vbits (void *dest,
+ void *src,
+ size_t length)
+{
+#ifdef WITH_VALGRIND
+ int vbits_setup = 0;
+ void *vbits = NULL;
+
+ if (RUNNING_ON_VALGRIND) {
+ vbits = malloc (length);
+ if (vbits != NULL)
+ vbits_setup = VALGRIND_GET_VBITS (src, vbits, length);
+ VALGRIND_MAKE_MEM_DEFINED (src, length);
+ }
+#endif
+
+ memcpy (dest, src, length);
+
+#ifdef WITH_VALGRIND
+ if (vbits_setup == 1) {
+ VALGRIND_SET_VBITS (dest, vbits, length);
+ VALGRIND_SET_VBITS (src, vbits, length);
+ }
+ free (vbits);
+#endif
+}
+
+static void*
+sec_realloc (Block *block,
+ const char *tag,
+ void *memory,
+ size_t length)
+{
+ Cell *cell, *other;
+ word_t *word;
+ size_t n_words;
+ size_t valid;
+ void *alloc;
+
+ /* Standard realloc behavior, should have been handled elsewhere */
+ g_assert (memory != NULL);
+ g_assert (length > 0);
+ g_assert (tag != NULL);
+
+ /* Dig out where the meta should be */
+ word = memory;
+ --word;
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_DEFINED (word, sizeof (word_t));
+#endif
+
+ g_assert (sec_is_valid_word (block, word));
+ g_assert (pool_valid (*word));
+ cell = *word;
+
+ /* Validate that it's actually for real */
+ sec_check_guards (cell);
+ g_assert (cell->requested > 0);
+ g_assert (cell->tag != NULL);
+
+ /* The amount of valid data */
+ valid = cell->requested;
+
+ /* How many words we actually want */
+ n_words = sec_size_to_words (length) + 2;
+
+ /* Less memory is required than is in the cell */
+ if (n_words <= cell->n_words) {
+
+ /* TODO: No shrinking behavior yet */
+ cell->requested = length;
+ alloc = sec_cell_to_memory (cell);
+
+ /*
+ * Even though we may be reusing the same cell, that doesn't
+ * mean that the allocation is shrinking. It could have shrunk
+ * and is now expanding back some.
+ */
+ if (length < valid)
+ sec_clear_undefined (alloc, length, valid);
+
+ return alloc;
+ }
+
+ /* Need braaaaaiiiiiinsss... */
+ while (cell->n_words < n_words) {
+
+ /* See if we have a neighbor who can give us some memory */
+ other = sec_neighbor_after (block, cell);
+ if (!other || other->requested != 0)
+ break;
+
+ /* Eat the whole neighbor if not too big */
+ if (n_words - cell->n_words + WASTE >= other->n_words) {
+ cell->n_words += other->n_words;
+ sec_write_guards (cell);
+ sec_remove_cell_ring (&block->unused_cells, other);
+ pool_free (other);
+
+ /* Steal from the neighbor */
+ } else {
+ other->words += n_words - cell->n_words;
+ other->n_words -= n_words - cell->n_words;
+ sec_write_guards (other);
+ cell->n_words = n_words;
+ sec_write_guards (cell);
+ }
+ }
+
+ if (cell->n_words >= n_words) {
+ cell->requested = length;
+ cell->tag = tag;
+ alloc = sec_cell_to_memory (cell);
+ sec_clear_undefined (alloc, valid, length);
+ return alloc;
+ }
+
+ /* That didn't work, try alloc/free */
+ alloc = sec_alloc (block, tag, length);
+ if (alloc) {
+ memcpy_with_vbits (alloc, memory, valid);
+ sec_free (block, memory);
+ }
+
+ return alloc;
+}
+
+
+static size_t
+sec_allocated (Block *block, void *memory)
+{
+ Cell *cell;
+ word_t *word;
+
+ g_assert (block);
+ g_assert (memory);
+
+ word = memory;
+ --word;
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_DEFINED (word, sizeof (word_t));
+#endif
+
+ /* Lookup the meta for this memory block (using guard pointer) */
+ g_assert (sec_is_valid_word (block, word));
+ g_assert (pool_valid (*word));
+ cell = *word;
+
+ sec_check_guards (cell);
+ g_assert (cell->requested > 0);
+ g_assert (cell->tag != NULL);
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_NOACCESS (word, sizeof (word_t));
+#endif
+
+ return cell->requested;
+}
+
+static void
+sec_validate (Block *block)
+{
+ Cell *cell;
+ word_t *word, *last;
+
+#ifdef WITH_VALGRIND
+ if (RUNNING_ON_VALGRIND)
+ return;
+#endif
+
+ word = block->words;
+ last = word + block->n_words;
+
+ for (;;) {
+ g_assert (word < last);
+
+ g_assert (sec_is_valid_word (block, word));
+ g_assert (pool_valid (*word));
+ cell = *word;
+
+ /* Validate that it's actually for real */
+ sec_check_guards (cell);
+
+ /* Is it an allocated block? */
+ if (cell->requested > 0) {
+ g_assert (cell->tag != NULL);
+ g_assert (cell->next != NULL);
+ g_assert (cell->prev != NULL);
+ g_assert (cell->next->prev == cell);
+ g_assert (cell->prev->next == cell);
+ g_assert (cell->requested <= (cell->n_words - 2) * sizeof (word_t));
+
+ /* An unused block */
+ } else {
+ g_assert (cell->tag == NULL);
+ g_assert (cell->next != NULL);
+ g_assert (cell->prev != NULL);
+ g_assert (cell->next->prev == cell);
+ g_assert (cell->prev->next == cell);
+ }
+
+ word += cell->n_words;
+ if (word == last)
+ break;
+ }
+}
+
+/* -----------------------------------------------------------------------------
+ * LOCKED MEMORY
+ */
+
+static void*
+sec_acquire_pages (size_t *sz,
+ const char *during_tag)
+{
+ g_assert (sz);
+ g_assert (*sz);
+ g_assert (during_tag);
+
+#if defined(HAVE_MLOCK) && defined(HAVE_MMAP)
+ /* Make sure sz is a multiple of the page size */
+ unsigned long pgsize = getpagesize ();
+
+ *sz = (*sz + pgsize -1) & ~(pgsize - 1);
+
+ void *pages = mmap (0, *sz, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
+ if (pages == MAP_FAILED) {
+ if (show_warning && gtk_secure_warnings)
+ fprintf (stderr, "couldn't map %lu bytes of memory (%s): %s\n",
+ (unsigned long)*sz, during_tag, strerror (errno));
+ show_warning = 0;
+ return NULL;
+ }
+
+ if (mlock (pages, *sz) < 0) {
+ if (show_warning && gtk_secure_warnings && errno != EPERM) {
+ fprintf (stderr, "couldn't lock %lu bytes of memory (%s): %s\n",
+ (unsigned long)*sz, during_tag, strerror (errno));
+ show_warning = 0;
+ }
+ munmap (pages, *sz);
+ return NULL;
+ }
+
+ DEBUG_ALLOC ("gtk-secure-memory: new block ", *sz);
+
+ show_warning = 1;
+ return pages;
+
+#else
+ if (show_warning && gtk_secure_warnings)
+ fprintf (stderr, "your system does not support private memory");
+ show_warning = 0;
+ return NULL;
+#endif
+
+}
+
+static void
+sec_release_pages (void *pages, size_t sz)
+{
+ g_assert (pages);
+
+#if defined(HAVE_MLOCK)
+ g_assert (sz % getpagesize () == 0);
+
+ if (munlock (pages, sz) < 0 && gtk_secure_warnings)
+ fprintf (stderr, "couldn't unlock private memory: %s\n", strerror (errno));
+
+ if (munmap (pages, sz) < 0 && gtk_secure_warnings)
+ fprintf (stderr, "couldn't unmap private anonymous memory: %s\n", strerror (errno));
+
+ DEBUG_ALLOC ("gtk-secure-memory: freed block ", sz);
+
+#else
+ g_assert (FALSE);
+#endif
+}
+
+/* -----------------------------------------------------------------------------
+ * MANAGE DIFFERENT BLOCKS
+ */
+
+static Block *all_blocks = NULL;
+
+static Block*
+sec_block_create (size_t size,
+ const char *during_tag)
+{
+ Block *block;
+ Cell *cell;
+
+ g_assert (during_tag);
+
+ /* We can force all all memory to be malloced */
+ if (getenv ("SECMEM_FORCE_FALLBACK"))
+ return NULL;
+
+ block = pool_alloc ();
+ if (!block)
+ return NULL;
+
+ cell = pool_alloc ();
+ if (!cell) {
+ pool_free (block);
+ return NULL;
+ }
+
+ /* The size above is a minimum, we're free to go bigger */
+ if (size < DEFAULT_BLOCK_SIZE)
+ size = DEFAULT_BLOCK_SIZE;
+
+ block->words = sec_acquire_pages (&size, during_tag);
+ block->n_words = size / sizeof (word_t);
+ if (!block->words) {
+ pool_free (block);
+ pool_free (cell);
+ return NULL;
+ }
+
+#ifdef WITH_VALGRIND
+ VALGRIND_MAKE_MEM_DEFINED (block->words, size);
+#endif
+
+ /* The first cell to allocate from */
+ cell->words = block->words;
+ cell->n_words = block->n_words;
+ cell->requested = 0;
+ sec_write_guards (cell);
+ sec_insert_cell_ring (&block->unused_cells, cell);
+
+ block->next = all_blocks;
+ all_blocks = block;
+
+ return block;
+}
+
+static void
+sec_block_destroy (Block *block)
+{
+ Block *bl, **at;
+ Cell *cell;
+
+ g_assert (block);
+ g_assert (block->words);
+ g_assert (block->n_used == 0);
+
+ /* Remove from the list */
+ for (at = &all_blocks, bl = *at; bl; at = &bl->next, bl = *at) {
+ if (bl == block) {
+ *at = block->next;
+ break;
+ }
+ }
+
+ /* Must have been found */
+ g_assert (bl == block);
+ g_assert (block->used_cells == NULL);
+
+ /* Release all the meta data cells */
+ while (block->unused_cells) {
+ cell = block->unused_cells;
+ sec_remove_cell_ring (&block->unused_cells, cell);
+ pool_free (cell);
+ }
+
+ /* Release all pages of secure memory */
+ sec_release_pages (block->words, block->n_words * sizeof (word_t));
+
+ pool_free (block);
+}
+
+/* ------------------------------------------------------------------------
+ * PUBLIC FUNCTIONALITY
+ */
+
+void*
+gtk_secure_alloc_full (const char *tag,
+ size_t length,
+ int flags)
+{
+ Block *block;
+ void *memory = NULL;
+
+ if (tag == NULL)
+ tag = "?";
+
+ if (length > 0xFFFFFFFF / 2) {
+ if (gtk_secure_warnings)
+ fprintf (stderr, "tried to allocate an insane amount of memory: %lu\n",
+ (unsigned long)length);
+ return NULL;
+ }
+
+ /* Can't allocate zero bytes */
+ if (length == 0)
+ return NULL;
+
+ DO_LOCK ();
+
+ for (block = all_blocks; block; block = block->next) {
+ memory = sec_alloc (block, tag, length);
+ if (memory)
+ break;
+ }
+
+ /* None of the current blocks have space, allocate new */
+ if (!memory) {
+ block = sec_block_create (length, tag);
+ if (block)
+ memory = sec_alloc (block, tag, length);
+ }
+
+#ifdef WITH_VALGRIND
+ if (memory != NULL)
+ VALGRIND_MALLOCLIKE_BLOCK (memory, length, sizeof (void*), 1);
+#endif
+
+ DO_UNLOCK ();
+
+ if (!memory && (flags & GTK_SECURE_USE_FALLBACK) && GTK_SECURE_GLOBALS.fallback_alloc != NULL) {
+ memory = GTK_SECURE_GLOBALS.fallback_alloc (NULL, length);
+ if (memory) /* Our returned memory is always zeroed */
+ memset (memory, 0, length);
+ }
+
+ if (!memory)
+ errno = ENOMEM;
+
+ return memory;
+}
+
+void*
+gtk_secure_realloc_full (const char *tag,
+ void *memory,
+ size_t length,
+ int flags)
+{
+ Block *block = NULL;
+ size_t previous = 0;
+ int donew = 0;
+ void *alloc = NULL;
+
+ if (tag == NULL)
+ tag = "?";
+
+ if (length > 0xFFFFFFFF / 2) {
+ if (gtk_secure_warnings)
+ fprintf (stderr, "tried to allocate an excessive amount of memory: %lu\n",
+ (unsigned long)length);
+ return NULL;
+ }
+
+ if (memory == NULL)
+ return gtk_secure_alloc_full (tag, length, flags);
+ if (!length) {
+ gtk_secure_free_full (memory, flags);
+ return NULL;
+ }
+
+ DO_LOCK ();
+
+ /* Find out where it belongs to */
+ for (block = all_blocks; block; block = block->next) {
+ if (sec_is_valid_word (block, memory)) {
+ previous = sec_allocated (block, memory);
+
+#ifdef WITH_VALGRIND
+ /* Let valgrind think we are unallocating so that it'll validate */
+ VALGRIND_FREELIKE_BLOCK (memory, sizeof (word_t));
+#endif
+
+ alloc = sec_realloc (block, tag, memory, length);
+
+#ifdef WITH_VALGRIND
+ /* Now tell valgrind about either the new block or old one */
+ VALGRIND_MALLOCLIKE_BLOCK (alloc ? alloc : memory,
+ alloc ? length : previous,
+ sizeof (word_t), 1);
+#endif
+ break;
+ }
+ }
+
+ /* If it didn't work we may need to allocate a new block */
+ if (block && !alloc)
+ donew = 1;
+
+ if (block && block->n_used == 0)
+ sec_block_destroy (block);
+
+ DO_UNLOCK ();
+
+ if (!block) {
+ if ((flags & GTK_SECURE_USE_FALLBACK) && GTK_SECURE_GLOBALS.fallback_alloc) {
+ /*
+ * In this case we can't zero the returned memory,
+ * because we don't know what the block size was.
+ */
+ return GTK_SECURE_GLOBALS.fallback_alloc (memory, length);
+ } else {
+ if (gtk_secure_warnings)
+ fprintf (stderr, "memory does not belong to secure memory pool: 0x%08"
G_GUINTPTR_FORMAT "x\n",
+ (guintptr) memory);
+ g_assert (0 && "memory does does not belong to secure memory pool");
+ return NULL;
+ }
+ }
+
+ if (donew) {
+ alloc = gtk_secure_alloc_full (tag, length, flags);
+ if (alloc) {
+ memcpy_with_vbits (alloc, memory, previous);
+ gtk_secure_free_full (memory, flags);
+ }
+ }
+
+ if (!alloc)
+ errno = ENOMEM;
+
+ return alloc;
+}
+
+void
+gtk_secure_free (void *memory)
+{
+ gtk_secure_free_full (memory, GTK_SECURE_USE_FALLBACK);
+}
+
+void
+gtk_secure_free_full (void *memory, int flags)
+{
+ Block *block = NULL;
+
+ if (memory == NULL)
+ return;
+
+ DO_LOCK ();
+
+ /* Find out where it belongs to */
+ for (block = all_blocks; block; block = block->next) {
+ if (sec_is_valid_word (block, memory))
+ break;
+ }
+
+#ifdef WITH_VALGRIND
+ /* We like valgrind's warnings, so give it a first whack at checking for errors */
+ if (block != NULL || !(flags & GTK_SECURE_USE_FALLBACK))
+ VALGRIND_FREELIKE_BLOCK (memory, sizeof (word_t));
+#endif
+
+ if (block != NULL) {
+ sec_free (block, memory);
+ if (block->n_used == 0)
+ sec_block_destroy (block);
+ }
+
+ DO_UNLOCK ();
+
+ if (!block) {
+ if ((flags & GTK_SECURE_USE_FALLBACK) && GTK_SECURE_GLOBALS.fallback_free) {
+ GTK_SECURE_GLOBALS.fallback_free (memory);
+ } else {
+ if (gtk_secure_warnings)
+ fprintf (stderr, "memory does not belong to secure memory pool: 0x%08"
G_GUINTPTR_FORMAT "x\n",
+ (guintptr) memory);
+ g_assert (0 && "memory does does not belong to secure memory pool");
+ }
+ }
+}
+
+int
+gtk_secure_check (const void *memory)
+{
+ Block *block = NULL;
+
+ DO_LOCK ();
+
+ /* Find out where it belongs to */
+ for (block = all_blocks; block; block = block->next) {
+ if (sec_is_valid_word (block, (word_t*)memory))
+ break;
+ }
+
+ DO_UNLOCK ();
+
+ return block == NULL ? 0 : 1;
+}
+
+void
+gtk_secure_validate (void)
+{
+ Block *block = NULL;
+
+ DO_LOCK ();
+
+ for (block = all_blocks; block; block = block->next)
+ sec_validate (block);
+
+ DO_UNLOCK ();
+}
+
+
+static gtk_secure_rec *
+records_for_ring (Cell *cell_ring,
+ gtk_secure_rec *records,
+ unsigned int *count,
+ unsigned int *total)
+{
+ gtk_secure_rec *new_rec;
+ unsigned int allocated = *count;
+ Cell *cell;
+
+ cell = cell_ring;
+ do {
+ if (*count >= allocated) {
+ new_rec = realloc (records, sizeof (gtk_secure_rec) * (allocated + 32));
+ if (new_rec == NULL) {
+ *count = 0;
+ free (records);
+ return NULL;
+ } else {
+ records = new_rec;
+ allocated += 32;
+ }
+ }
+
+ if (cell != NULL) {
+ records[*count].request_length = cell->requested;
+ records[*count].block_length = cell->n_words * sizeof (word_t);
+ records[*count].tag = cell->tag;
+ (*count)++;
+ (*total) += cell->n_words;
+ cell = cell->next;
+ }
+ } while (cell != NULL && cell != cell_ring);
+
+ return records;
+}
+
+gtk_secure_rec *
+gtk_secure_records (unsigned int *count)
+{
+ gtk_secure_rec *records = NULL;
+ Block *block = NULL;
+ unsigned int total;
+
+ *count = 0;
+
+ DO_LOCK ();
+
+ for (block = all_blocks; block != NULL; block = block->next) {
+ total = 0;
+
+ records = records_for_ring (block->unused_cells, records, count, &total);
+ if (records == NULL)
+ break;
+ records = records_for_ring (block->used_cells, records, count, &total);
+ if (records == NULL)
+ break;
+
+ /* Make sure this actualy accounts for all memory */
+ g_assert (total == block->n_words);
+ }
+
+ DO_UNLOCK ();
+
+ return records;
+}
+
+char*
+gtk_secure_strdup_full (const char *tag,
+ const char *str,
+ int options)
+{
+ size_t len;
+ char *res;
+
+ if (!str)
+ return NULL;
+
+ len = strlen (str) + 1;
+ res = (char *)gtk_secure_alloc_full (tag, len, options);
+ strcpy (res, str);
+ return res;
+}
+
+char *
+gtk_secure_strndup_full (const char *tag,
+ const char *str,
+ size_t length,
+ int options)
+{
+ size_t len;
+ char *res;
+ const char *end;
+
+ if (!str)
+ return NULL;
+
+ end = memchr (str, '\0', length);
+ if (end != NULL)
+ length = (end - str);
+ len = length + 1;
+ res = (char *)gtk_secure_alloc_full (tag, len, options);
+ memcpy (res, str, len);
+ return res;
+}
+
+void
+gtk_secure_clear (void *p, size_t length)
+{
+ volatile char *vp;
+
+ if (p == NULL)
+ return;
+
+ vp = (volatile char*)p;
+ while (length) {
+ *vp = 0xAA;
+ vp++;
+ length--;
+ }
+}
+
+void
+gtk_secure_strclear (char *str)
+{
+ if (!str)
+ return;
+ gtk_secure_clear ((unsigned char*)str, strlen (str));
+}
+
+void
+gtk_secure_strfree (char *str)
+{
+ /*
+ * If we're using unpageable 'secure' memory, then the free call
+ * should zero out the memory, but because on certain platforms
+ * we may be using normal memory, zero it out here just in case.
+ */
+
+ gtk_secure_strclear (str);
+ gtk_secure_free_full (str, GTK_SECURE_USE_FALLBACK);
+}
diff --git a/gtk/gtksecurememoryprivate.h b/gtk/gtksecurememoryprivate.h
new file mode 100644
index 0000000000..0209d4fc11
--- /dev/null
+++ b/gtk/gtksecurememoryprivate.h
@@ -0,0 +1,95 @@
+/* gtksecurememoryprivate.h - Allocator for non-pageable memory
+
+ Copyright 2007 Stefan Walter
+ Copyright 2020 GNOME Foundation
+
+ SPDX-License-Identifier: LGPL-2.0-or-later
+
+ The Gnome Keyring Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The Gnome Keyring Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the Gnome Library; see the file COPYING.LIB. If not,
+ see <http://www.gnu.org/licenses/>.
+
+ Author: Stef Walter <stef memberwebs com>
+*/
+
+#pragma once
+
+#include <stdlib.h>
+
+/*
+ * Main functionality
+ *
+ * Allocations return NULL on failure.
+ */
+
+#define GTK_SECURE_USE_FALLBACK 0x0001
+
+void * gtk_secure_alloc_full (const char *tag,
+ size_t length,
+ int options);
+
+void * gtk_secure_realloc_full (const char *tag,
+ void *p,
+ size_t length,
+ int options);
+
+void gtk_secure_free (void *p);
+
+void gtk_secure_free_full (void *p,
+ int fallback);
+
+void gtk_secure_clear (void *p,
+ size_t length);
+
+int gtk_secure_check (const void *p);
+
+void gtk_secure_validate (void);
+
+char * gtk_secure_strdup_full (const char *tag,
+ const char *str,
+ int options);
+
+char * gtk_secure_strndup_full (const char *tag,
+ const char *str,
+ size_t length,
+ int options);
+
+void gtk_secure_strclear (char *str);
+
+void gtk_secure_strfree (char *str);
+
+/* Simple wrappers */
+
+static inline void *gtk_secure_alloc (size_t length) {
+ return gtk_secure_alloc_full ("gtk", length, GTK_SECURE_USE_FALLBACK);
+}
+
+static inline void *gtk_secure_realloc (void *p, size_t length) {
+ return gtk_secure_realloc_full ("gtk", p, length, GTK_SECURE_USE_FALLBACK);
+}
+
+static inline void *gtk_secure_strdup (const char *str) {
+ return gtk_secure_strdup_full ("gtk", str, GTK_SECURE_USE_FALLBACK);
+}
+
+static inline void *gtk_secure_strndup (const char *str, size_t length) {
+ return gtk_secure_strndup_full ("gtk", str, length, GTK_SECURE_USE_FALLBACK);
+}
+
+typedef struct {
+ const char *tag;
+ size_t request_length;
+ size_t block_length;
+} gtk_secure_rec;
+
+gtk_secure_rec * gtk_secure_records (unsigned int *count);
diff --git a/gtk/meson.build b/gtk/meson.build
index 13bdd71d61..c644ac9696 100644
--- a/gtk/meson.build
+++ b/gtk/meson.build
@@ -134,6 +134,7 @@ gtk_private_sources = files([
'gtkscaler.c',
'gtksearchengine.c',
'gtksearchenginemodel.c',
+ 'gtksecurememory.c',
'gtksizerequestcache.c',
'gtksortkeys.c',
'gtkstyleanimation.c',
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