wolfssl-w32/linuxkm/linuxkm_memory.c

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/* linuxkm_memory.c
*
* Copyright (C) 2006-2023 wolfSSL Inc.
*
* This file is part of wolfSSL.
*
* wolfSSL is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* wolfSSL 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
*/
/* included by wolfcrypt/src/memory.c */
#ifdef HAVE_KVMALLOC
/* adapted from kvrealloc() draft by Changli Gao, 2010-05-13 */
void *lkm_realloc(void *ptr, size_t newsize) {
void *nptr;
size_t oldsize;
if (unlikely(newsize == 0)) {
kvfree(ptr);
return ZERO_SIZE_PTR;
}
if (unlikely(ptr == NULL))
return kvmalloc_node(newsize, GFP_KERNEL, NUMA_NO_NODE);
if (is_vmalloc_addr(ptr)) {
/* no way to discern the size of the old allocation,
* because the kernel doesn't export find_vm_area(). if
* it did, we could then call get_vm_area_size() on the
* returned struct vm_struct.
*/
return NULL;
} else {
#ifndef __PIE__
struct page *page;
page = virt_to_head_page(ptr);
if (PageSlab(page) || PageCompound(page)) {
if (newsize < PAGE_SIZE)
#endif /* ! __PIE__ */
return krealloc(ptr, newsize, GFP_KERNEL);
#ifndef __PIE__
oldsize = ksize(ptr);
} else {
oldsize = page->private;
if (newsize <= oldsize)
return ptr;
}
#endif /* ! __PIE__ */
}
nptr = kvmalloc_node(newsize, GFP_KERNEL, NUMA_NO_NODE);
if (nptr != NULL) {
memcpy(nptr, ptr, oldsize);
kvfree(ptr);
}
return nptr;
}
#endif /* HAVE_KVMALLOC */
#if defined(WOLFSSL_LINUXKM_USE_SAVE_VECTOR_REGISTERS) && defined(CONFIG_X86)
static unsigned int wc_linuxkm_fpu_states_n_tracked = 0;
struct wc_thread_fpu_count_ent {
volatile pid_t pid;
unsigned int fpu_state;
};
struct wc_thread_fpu_count_ent *wc_linuxkm_fpu_states = NULL;
#define WC_FPU_COUNT_MASK 0x7fffffffU
#define WC_FPU_SAVED_MASK 0x80000000U
WARN_UNUSED_RESULT int allocate_wolfcrypt_linuxkm_fpu_states(void)
{
if (wc_linuxkm_fpu_states != NULL) {
static int warned_for_repeat_alloc = 0;
if (! warned_for_repeat_alloc) {
pr_err("attempt at repeat allocation"
" in allocate_wolfcrypt_linuxkm_fpu_states\n");
warned_for_repeat_alloc = 1;
}
return BAD_STATE_E;
}
if (nr_cpu_ids >= 16)
wc_linuxkm_fpu_states_n_tracked = nr_cpu_ids * 2;
else
wc_linuxkm_fpu_states_n_tracked = 32;
wc_linuxkm_fpu_states =
(struct wc_thread_fpu_count_ent *)malloc(
wc_linuxkm_fpu_states_n_tracked * sizeof(wc_linuxkm_fpu_states[0]));
if (! wc_linuxkm_fpu_states) {
pr_err("allocation of %lu bytes for "
"wc_linuxkm_fpu_states failed.\n",
nr_cpu_ids * sizeof(struct fpu_state *));
return MEMORY_E;
}
memset(wc_linuxkm_fpu_states, 0, wc_linuxkm_fpu_states_n_tracked * sizeof(wc_linuxkm_fpu_states[0]));
return 0;
}
void free_wolfcrypt_linuxkm_fpu_states(void) {
struct wc_thread_fpu_count_ent *i, *i_endptr;
pid_t i_pid;
if (wc_linuxkm_fpu_states == NULL) {
pr_err("free_wolfcrypt_linuxkm_fpu_states called"
" before allocate_wolfcrypt_linuxkm_fpu_states.\n");
return;
}
for (i = wc_linuxkm_fpu_states,
i_endptr = &wc_linuxkm_fpu_states[wc_linuxkm_fpu_states_n_tracked];
i < i_endptr;
++i)
{
i_pid = __atomic_load_n(&i->pid, __ATOMIC_CONSUME);
if (i_pid == 0)
continue;
if (i->fpu_state != 0) {
pr_err("free_wolfcrypt_linuxkm_fpu_states called"
" with nonzero state 0x%x for pid %d.\n", i->fpu_state, i_pid);
i->fpu_state = 0;
}
}
free(wc_linuxkm_fpu_states);
wc_linuxkm_fpu_states = NULL;
}
/* lock-(mostly)-free thread-local storage facility for tracking recursive fpu pushing/popping */
static struct wc_thread_fpu_count_ent *wc_linuxkm_fpu_state_assoc(int create_p) {
struct wc_thread_fpu_count_ent *i, *i_endptr, *i_empty;
pid_t my_pid = task_pid_nr(current), i_pid;
{
static int _warned_on_null = 0;
if (wc_linuxkm_fpu_states == NULL)
{
if (_warned_on_null == 0) {
pr_err("wc_linuxkm_fpu_state_assoc called by pid %d"
" before allocate_wolfcrypt_linuxkm_fpu_states.\n", my_pid);
_warned_on_null = 1;
}
return NULL;
}
}
i_endptr = &wc_linuxkm_fpu_states[wc_linuxkm_fpu_states_n_tracked];
for (;;) {
for (i = wc_linuxkm_fpu_states,
i_empty = NULL;
i < i_endptr;
++i)
{
i_pid = __atomic_load_n(&i->pid, __ATOMIC_CONSUME);
if (i_pid == my_pid)
return i;
if ((i_empty == NULL) && (i_pid == 0))
i_empty = i;
}
if ((i_empty == NULL) || (! create_p))
return NULL;
i_pid = 0;
if (__atomic_compare_exchange_n(
&(i_empty->pid),
&i_pid,
my_pid,
0 /* weak */,
__ATOMIC_SEQ_CST /* success_memmodel */,
__ATOMIC_SEQ_CST /* failure_memmodel */))
{
return i_empty;
}
}
}
static void wc_linuxkm_fpu_state_free(struct wc_thread_fpu_count_ent *ent) {
if (ent->fpu_state != 0) {
static int warned_nonzero_fpu_state = 0;
if (! warned_nonzero_fpu_state) {
pr_err("wc_linuxkm_fpu_state_free for pid %d"
" with nonzero fpu_state 0x%x.\n", ent->pid, ent->fpu_state);
warned_nonzero_fpu_state = 1;
}
ent->fpu_state = 0;
}
__atomic_store_n(&ent->pid, 0, __ATOMIC_RELEASE);
}
WARN_UNUSED_RESULT int save_vector_registers_x86(void)
{
struct wc_thread_fpu_count_ent *pstate = wc_linuxkm_fpu_state_assoc(1);
if (pstate == NULL)
return ENOMEM;
/* allow for nested calls */
if (pstate->fpu_state != 0U) {
if ((pstate->fpu_state & WC_FPU_COUNT_MASK)
== WC_FPU_COUNT_MASK)
{
pr_err("save_vector_registers_x86 recursion register overflow for "
"pid %d.\n", pstate->pid);
return BAD_STATE_E;
} else {
++pstate->fpu_state;
return 0;
}
}
if (irq_fpu_usable()) {
#if defined(CONFIG_SMP) && !defined(CONFIG_PREEMPT_COUNT) && (LINUX_VERSION_CODE >= KERNEL_VERSION(5, 7, 0))
/* inhibit migration, which gums up the algorithm in kernel_fpu_{begin,end}(). */
migrate_disable();
#endif
kernel_fpu_begin();
pstate->fpu_state = 1U; /* set msb 0 to trigger kernel_fpu_end() at cleanup. */
} else if (in_nmi() || (hardirq_count() > 0) || (softirq_count() > 0)) {
static int warned_fpu_forbidden = 0;
if (! warned_fpu_forbidden)
pr_err("save_vector_registers_x86 called from IRQ handler.\n");
wc_linuxkm_fpu_state_free(pstate);
return EPERM;
} else {
#if defined(CONFIG_SMP) && !defined(CONFIG_PREEMPT_COUNT) && (LINUX_VERSION_CODE >= KERNEL_VERSION(5, 7, 0))
migrate_disable();
#endif
/* assume already safely in_kernel_fpu. */
pstate->fpu_state =
WC_FPU_SAVED_MASK + 1U; /* set msb 1 to inhibit kernel_fpu_end() at cleanup. */
}
return 0;
}
void restore_vector_registers_x86(void)
{
struct wc_thread_fpu_count_ent *pstate = wc_linuxkm_fpu_state_assoc(0);
if (pstate == NULL) {
pr_err("restore_vector_registers_x86 called by pid %d "
"with no saved state.\n", task_pid_nr(current));
return;
}
if ((--pstate->fpu_state & WC_FPU_COUNT_MASK) > 0U) {
return;
}
if (pstate->fpu_state == 0U)
kernel_fpu_end();
else
pstate->fpu_state = 0U;
#if defined(CONFIG_SMP) && !defined(CONFIG_PREEMPT_COUNT) && (LINUX_VERSION_CODE >= KERNEL_VERSION(5, 7, 0))
migrate_enable();
#endif
wc_linuxkm_fpu_state_free(pstate);
return;
}
#endif /* WOLFSSL_LINUXKM_USE_SAVE_VECTOR_REGISTERS && CONFIG_X86 */
#if defined(__PIE__) && (LINUX_VERSION_CODE >= KERNEL_VERSION(6, 1, 0))
/* needed in 6.1+ because show_free_areas() static definition in mm.h calls
* __show_free_areas(), which isn't exported (neither was show_free_areas()).
*/
void my__show_free_areas(
unsigned int flags,
nodemask_t *nodemask,
int max_zone_idx)
{
(void)flags;
(void)nodemask;
(void)max_zone_idx;
return;
}
#endif