// SPDX-License-Identifier: GPL-2.0+
//
// Security related flags and so on.
//
// Copyright 2018, Michael Ellerman, IBM Corporation.
#include <linux/cpu.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/memblock.h>
#include <linux/nospec.h>
#include <linux/prctl.h>
#include <linux/seq_buf.h>
#include <linux/debugfs.h>
#include <asm/asm-prototypes.h>
#include <asm/code-patching.h>
#include <asm/security_features.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/inst.h>
#include "setup.h"
u64 powerpc_security_features __read_mostly = SEC_FTR_DEFAULT;
enum branch_cache_flush_type {
BRANCH_CACHE_FLUSH_NONE = 0x1,
BRANCH_CACHE_FLUSH_SW = 0x2,
BRANCH_CACHE_FLUSH_HW = 0x4,
};
static enum branch_cache_flush_type count_cache_flush_type = BRANCH_CACHE_FLUSH_NONE;
static enum branch_cache_flush_type link_stack_flush_type = BRANCH_CACHE_FLUSH_NONE;
bool barrier_nospec_enabled;
static bool no_nospec;
static bool btb_flush_enabled;
#if defined(CONFIG_PPC_E500) || defined(CONFIG_PPC_BOOK3S_64)
static bool no_spectrev2;
#endif
static void enable_barrier_nospec(bool enable)
{
barrier_nospec_enabled = enable;
do_barrier_nospec_fixups(enable);
}
void __init setup_barrier_nospec(void)
{
bool enable;
/*
* It would make sense to check SEC_FTR_SPEC_BAR_ORI31 below as well.
* But there's a good reason not to. The two flags we check below are
* both are enabled by default in the kernel, so if the hcall is not
* functional they will be enabled.
* On a system where the host firmware has been updated (so the ori
* functions as a barrier), but on which the hypervisor (KVM/Qemu) has
* not been updated, we would like to enable the barrier. Dropping the
* check for SEC_FTR_SPEC_BAR_ORI31 achieves that. The only downside is
* we potentially enable the barrier on systems where the host firmware
* is not updated, but that's harmless as it's a no-op.
*/
enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR);
if (!no_nospec && !cpu_mitigations_off())
enable_barrier_nospec(enable);
}
static int __init handle_nospectre_v1(char *p)
{
no_nospec = true;
return 0;
}
early_param("nospectre_v1", handle_nospectre_v1);
#ifdef CONFIG_DEBUG_FS
static int barrier_nospec_set(void *data, u64 val)
{
switch (val) {
case 0:
case 1:
break;
default:
return -EINVAL;
}
if (!!val == !!barrier_nospec_enabled)
return 0;
enable_barrier_nospec(!!val);
return 0;
}
static int barrier_nospec_get(void *data, u64 *val)
{
*val = barrier_nospec_enabled ? 1 : 0;
return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(fops_barrier_nospec, barrier_nospec_get,
barrier_nospec_set, "%llu\n");
static __init int barrier_nospec_debugfs_init(void)
{
debugfs_create_file_unsafe("barrier_nospec", 0600,
arch_debugfs_dir, NULL,
&fops_barrier_nospec);
return 0;
}
device_initcall(barrier_nospec_debugfs_init);
static __init int security_feature_debugfs_init(void)
{
debugfs_create_x64("security_features", 0400, arch_debugfs_dir,
&powerpc_security_features);
return 0;
}
device_initcall(security_feature_debugfs_init);
#endif /* CONFIG_DEBUG_FS */
#if defined(CONFIG_PPC_E500) || defined(CONFIG_PPC_BOOK3S_64)
static int __init handle_nospectre_v2(char *p)
{
no_spectrev2 = true;
return 0;
}
early_param("nospectre_v2", handle_nospectre_v2);
#endif /* CONFIG_PPC_E500 || CONFIG_PPC_BOOK3S_64 */
#ifdef CONFIG_PPC_E500
void __init setup_spectre_v2(void)
{
if (no_spectrev2 || cpu_mitigations_off())
do_btb_flush_fixups();
else
btb_flush_enabled = true;
}
#endif /* CONFIG_PPC_E500 */
#ifdef CONFIG_PPC_BOOK3S_64
ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
{
bool thread_priv;
thread_priv = security_ftr_enabled(SEC_FTR_L1D_THREAD_PRIV);
if (rfi_flush) {
struct seq_buf s;
seq_buf_init(&s, buf, PAGE_SIZE - 1);
seq_buf_printf(&s, "Mitigation: RFI Flush");
if (thread_priv)
seq_buf_printf(&s, ", L1D private per thread");
seq_buf_printf(&s, "\n");
return s.len;
}
if (thread_priv)
return sprintf(buf, "Vulnerable: L1D private per thread\n");
if (!security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV) &&
!security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR))
return sprintf(buf, "Not affected\n");
return sprintf(buf, "Vulnerable\n");
}
ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *buf)
{
return cpu_show_meltdown(dev, attr, buf);
}
#endif
ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, char *buf)
{
struct seq_buf s;
seq_buf_init(&s, buf, PAGE_SIZE - 1);
if (security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR)) {
if (barrier_nospec_enabled)
seq_buf_printf(&s, "Mitigation: __user pointer sanitization");
else
seq_buf_printf(&s, "Vulnerable");
if (security_ftr_enabled(SEC_FTR_SPEC_BAR_ORI31))
seq_buf_printf(&s, ", ori31 speculation barrier enabled");
seq_buf_printf(&s, "\n");
} else
seq_buf_printf(&s, "Not affected\n");
return s.len;
}
ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, char *buf)
{
struct seq_buf s;
bool bcs, ccd;
seq_buf_init(&s, buf, PAGE_SIZE - 1);
bcs = security_ftr_enabled(SEC_FTR_BCCTRL_SERIALISED);
ccd = security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED);
if (bcs || ccd) {
seq_buf_printf(&s, "Mitigation: ");
if (bcs)
seq_buf_printf(&s, "Indirect branch serialisation (kernel only)");
if (bcs && ccd)
seq_buf_printf(&s, ", ");
if (ccd)
seq_buf_printf(&s, "Indirect branch cache disabled");
} else if (count_cache_flush_type != BRANCH_CACHE_FLUSH_NONE) {
seq_buf_printf(&s, "Mitigation: Software count cache flush");
if (count_cache_flush_type == BRANCH_CACHE_FLUSH_HW)
seq_buf_printf(&s, " (hardware accelerated)");
} else if (btb_flush_enabled) {
seq_buf_printf(&s, "Mitigation: Branch predictor state flush");
} else {
seq_buf_printf(&s, "Vulnerable");
}
if (bcs || ccd || count_cache_flush_type != BRANCH_CACHE_FLUSH_NONE) {
if (link_stack_flush_type != BRANCH_CACHE_FLUSH_NONE)
seq_buf_printf(&s, ", Software link stack flush");
if (link_stack_flush_type == BRANCH_CACHE_FLUSH_HW)
seq_buf_printf(&s, " (hardware accelerated)");
}
seq_buf_printf(&s, "\n");
return s.len;
}
#ifdef CONFIG_PPC_BOOK3S_64
/*
* Store-forwarding barrier support.
*/
static enum stf_barrier_type stf_enabled_flush_types;
static bool no_stf_barrier;
static bool stf_barrier;
static int __init handle_no_stf_barrier(char *p)
{
pr_info("stf-barrier: disabled on command line.");
no_stf_barrier = true;
return 0;
}
early_param("no_stf_barrier", handle_no_stf_barrier);
enum stf_barrier_type stf_barrier_type_get(void)
{
return stf_enabled_flush_types;
}
/* This is the generic flag used by other architectures */
static int __init handle_ssbd(char *p)
{
if (!p || strncmp(p, "auto", 5) == 0 || strncmp(p, "on", 2) == 0 ) {
/* Until firmware tells us, we have the barrier with auto */
return 0;
} else if (strncmp(p, "off", 3) == 0) {
handle_no_stf_barrier(NULL);
return 0;
} else
return 1;
return 0;
}
early_param("spec_store_bypass_disable", handle_ssbd);
/* This is the generic flag used by other architectures */
static int __init handle_no_ssbd(char *p)
{
handle_no_stf_barrier(NULL);
return 0;
}
early_param("nospec_store_bypass_disable", handle_no_ssbd);
static void stf_barrier_enable(bool enable)
{
if (enable)
do_stf_barrier_fixups(stf_enabled_flush_types);
else
do_stf_barrier_fixups(STF_BARRIER_NONE);
stf_barrier = enable;
}
void setup_stf_barrier(void)
{
enum stf_barrier_type type;
bool enable;
/* Default to fallback in case fw-features are not available */
if (cpu_has_feature(CPU_FTR_ARCH_300))
type = STF_BARRIER_EIEIO;
else if (cpu_has_feature(CPU_FTR_ARCH_207S))
type = STF_BARRIER_SYNC_ORI;
else if (cpu_has_feature(CPU_FTR_ARCH_206))
type = STF_BARRIER_FALLBACK;
else
type = STF_BARRIER_NONE;
enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
security_ftr_enabled(SEC_FTR_STF_BARRIER);
if (type == STF_BARRIER_FALLBACK) {
pr_info("stf-barrier: fallback barrier available\n");
} else if (type == STF_BARRIER_SYNC_ORI) {
pr_info("stf-barrier: hwsync barrier available\n");
} else if (type == STF_BARRIER_EIEIO) {
pr_info("stf-barrier: eieio barrier available\n");
}
stf_enabled_flush_types = type;
if (!no_stf_barrier && !cpu_mitigations_off())
stf_barrier_enable(enable);
}
ssize_t cpu_show_spec_store_bypass(struct device *dev, struct device_attribute *attr, char *buf)
{
if (stf_barrier && stf_enabled_flush_types != STF_BARRIER_NONE) {
const char *type;
switch (stf_enabled_flush_types) {
case STF_BARRIER_EIEIO:
type = "eieio";
break;
case STF_BARRIER_SYNC_ORI:
type = "hwsync";
break;
case STF_BARRIER_FALLBACK:
type = "fallback";
break;
default:
type = "unknown";
}
return sprintf(buf, "Mitigation: Kernel entry/exit barrier (%s)\n", type);
}
if (!security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV) &&
!security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR))
return sprintf(buf, "Not affected\n");
return sprintf(buf, "Vulnerable\n");
}
static int ssb_prctl_get(struct task_struct *task)
{
/*
* The STF_BARRIER feature is on by default, so if it's off that means
* firmware has explicitly said the CPU is not vulnerable via either
* the hypercall or device tree.
*/
if (!security_ftr_enabled(SEC_FTR_STF_BARRIER))
return PR_SPEC_NOT_AFFECTED;
/*
* If the system's CPU has no known barrier (see setup_stf_barrier())
* then assume that the CPU is not vulnerable.
*/
if (stf_enabled_flush_types == STF_BARRIER_NONE)
return PR_SPEC_NOT_AFFECTED;
/*
* Otherwise the CPU is vulnerable. The barrier is not a global or
* per-process mitigation, so the only value that can be reported here
* is PR_SPEC_ENABLE, which appears as "vulnerable" in /proc.
*/
return PR_SPEC_ENABLE;
}
int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which)
{
switch (which) {
case PR_SPEC_STORE_BYPASS:
return ssb_prctl_get(task);
default:
return -ENODEV;
}
}
#ifdef CONFIG_DEBUG_FS
static int stf_barrier_set(void *data, u64 val)
{
bool enable;
if (val == 1)
enable = true;
else if (val == 0)
enable = false;
else
return -EINVAL;
/* Only do anything if we're changing state */
if (enable != stf_barrier)
stf_barrier_enable(enable);
return 0;
}
static int stf_barrier_get(void *data, u64 *val)
{
*val = stf_barrier ? 1 : 0;
return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(fops_stf_barrier, stf_barrier_get, stf_barrier_set,
"%llu\n");
static __init int stf_barrier_debugfs_init(void)
{
debugfs_create_file_unsafe("stf_barrier", 0600, arch_debugfs_dir,
NULL, &fops_stf_barrier);
return 0;
}
device_initcall(stf_barrier_debugfs_init);
#endif /* CONFIG_DEBUG_FS */
static void update_branch_cache_flush(void)
{
u32 *site, __maybe_unused *site2;
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
site = &patch__call_kvm_flush_link_stack;
site2 = &patch__call_kvm_flush_link_stack_p9;
// This controls the branch from guest_exit_cont to kvm_flush_link_stack
if (link_stack_flush_type == BRANCH_CACHE_FLUSH_NONE) {
patch_instruction_site(site, ppc_inst(PPC_RAW_NOP()));
patch_instruction_site(site2, ppc_inst(PPC_RAW_NOP()));
} else {
// Could use HW flush, but that could also flush count cache
patch_branch_site(site, (u64)&kvm_flush_link_stack, BRANCH_SET_LINK);
patch_branch_site(site2, (u64)&kvm_flush_link_stack, BRANCH_SET_LINK);
}
#endif
// Patch out the bcctr first, then nop the rest
site = &patch__call_flush_branch_caches3;
patch_instruction_site(site, ppc_inst(PPC_RAW_NOP()));
site = &patch__call_flush_branch_caches2;
patch_instruction_site(site, ppc_inst(PPC_RAW_NOP()));
site = &patch__call_flush_branch_caches1;
patch_instruction_site(site, ppc_inst(PPC_RAW_NOP()));
// This controls the branch from _switch to flush_branch_caches
if (count_cache_flush_type == BRANCH_CACHE_FLUSH_NONE &&
link_stack_flush_type == BRANCH_CACHE_FLUSH_NONE) {
// Nothing to be done
} else if (count_cache_flush_type == BRANCH_CACHE_FLUSH_HW &&
link_stack_flush_type == BRANCH_CACHE_FLUSH_HW) {
// Patch in the bcctr last
site = &patch__call_flush_branch_caches1;
patch_instruction_site(site, ppc_inst(0x39207fff)); // li r9,0x7fff
site = &patch__call_flush_branch_caches2;
patch_instruction_site(site, ppc_inst(0x7d2903a6)); // mtctr r9
site = &patch__call_flush_branch_caches3;
patch_instruction_site(site, ppc_inst(PPC_INST_BCCTR_FLUSH));
} else {
patch_branch_site(site, (u64)&flush_branch_caches, BRANCH_SET_LINK);
// If we just need to flush the link stack, early return
if (count_cache_flush_type == BRANCH_CACHE_FLUSH_NONE) {
patch_instruction_site(&patch__flush_link_stack_return,
ppc_inst(PPC_RAW_BLR()));
// If we have flush instruction, early return
} else if (count_cache_flush_type == BRANCH_CACHE_FLUSH_HW) {
patch_instruction_site(&patch__flush_count_cache_return,
ppc_inst(PPC_RAW_BLR()));
}
}
}
static void toggle_branch_cache_flush(bool enable)
{
if (!enable || !security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE)) {
if (count_cache_flush_type != BRANCH_CACHE_FLUSH_NONE)
count_cache_flush_type = BRANCH_CACHE_FLUSH_NONE;
pr_info("count-cache-flush: flush disabled.\n");
} else {
if (security_ftr_enabled(SEC_FTR_BCCTR_FLUSH_ASSIST)) {
count_cache_flush_type = BRANCH_CACHE_FLUSH_HW;
pr_info("count-cache-flush: hardware flush enabled.\n");
} else {
count_cache_flush_type = BRANCH_CACHE_FLUSH_SW;
pr_info("count-cache-flush: software flush enabled.\n");
}
}
if (!enable || !security_ftr_enabled(SEC_FTR_FLUSH_LINK_STACK)) {
if (link_stack_flush_type != BRANCH_CACHE_FLUSH_NONE)
link_stack_flush_type = BRANCH_CACHE_FLUSH_NONE;
pr_info("link-stack-flush: flush disabled.\n");
} else {
if (security_ftr_enabled(SEC_FTR_BCCTR_LINK_FLUSH_ASSIST)) {
link_stack_flush_type = BRANCH_CACHE_FLUSH_HW;
pr_info("link-stack-flush: hardware flush enabled.\n");
} else {
link_stack_flush_type = BRANCH_CACHE_FLUSH_SW;
pr_info("link-stack-flush: software flush enabled.\n");
}
}
update_branch_cache_flush();
}
void setup_count_cache_flush(void)
{
bool enable = true;
if (no_spectrev2 || cpu_mitigations_off()) {
if (security_ftr_enabled(SEC_FTR_BCCTRL_SERIALISED) ||
security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED))
pr_warn("Spectre v2 mitigations not fully under software control, can't disable\n");
enable = false;
}
/*
* There's no firmware feature flag/hypervisor bit to tell us we need to
* flush the link stack on context switch. So we set it here if we see
* either of the Spectre v2 mitigations that aim to protect userspace.
*/
if (security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED) ||
security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE))
security_ftr_set(SEC_FTR_FLUSH_LINK_STACK);
toggle_branch_cache_flush(enable);
}
static enum l1d_flush_type enabled_flush_types;
static void *l1d_flush_fallback_area;
static bool no_rfi_flush;
static bool no_entry_flush;
static bool no_uaccess_flush;
bool rfi_flush;
static bool entry_flush;
static bool uaccess_flush;
DEFINE_STATIC_KEY_FALSE(uaccess_flush_key);
EXPORT_SYMBOL(uaccess_flush_key);
static int __init handle_no_rfi_flush(char *p)
{
pr_info("rfi-flush: disabled on command line.");
no_rfi_flush = true;
return 0;
}
early_param("no_rfi_flush", handle_no_rfi_flush);
static int __init handle_no_entry_flush(char *p)
{
pr_info("entry-flush: disabled on command line.");
no_entry_flush = true;
return 0;
}
early_param("no_entry_flush", handle_no_entry_flush);
static int __init handle_no_uaccess_flush(char *p)
{
pr_info("uaccess-flush: disabled on command line.");
no_uaccess_flush = true;
return 0;
}
early_param("no_uaccess_flush", handle_no_uaccess_flush);
/*
* The RFI flush is not KPTI, but because users will see doco that says to use
* nopti we hijack that option here to also disable the RFI flush.
*/
static int __init handle_no_pti(char *p)
{
pr_info("rfi-flush: disabling due to 'nopti' on command line.\n");
handle_no_rfi_flush(NULL);
return 0;
}
early_param("nopti", handle_no_pti);
static void do_nothing(void *unused)
{
/*
* We don't need to do the flush explicitly, just enter+exit kernel is
* sufficient, the RFI exit handlers will do the right thing.
*/
}
void rfi_flush_enable(bool enable)
{
if (enable) {
do_rfi_flush_fixups(enabled_flush_types);
on_each_cpu(do_nothing, NULL, 1);
} else
do_rfi_flush_fixups(L1D_FLUSH_NONE);
rfi_flush = enable;
}
static void entry_flush_enable(bool enable)
{
if (enable) {
do_entry_flush_fixups(enabled_flush_types);
on_each_cpu(do_nothing, NULL, 1);
} else {
do_entry_flush_fixups(L1D_FLUSH_NONE);
}
entry_flush = enable;
}
static void uaccess_flush_enable(bool enable)
{
if (enable) {
do_uaccess_flush_fixups(enabled_flush_types);
static_branch_enable(&uaccess_flush_key);
on_each_cpu(do_nothing, NULL, 1);
} else {
static_branch_disable(&uaccess_flush_key);
do_uaccess_flush_fixups(L1D_FLUSH_NONE);
}
uaccess_flush = enable;
}
static void __ref init_fallback_flush(void)
{
u64 l1d_size, limit;
int cpu;
/* Only allocate the fallback flush area once (at boot time). */
if (l1d_flush_fallback_area)
return;
l1d_size = ppc64_caches.l1d.size;
/*
* If there is no d-cache-size property in the device tree, l1d_size
* could be zero. That leads to the loop in the asm wrapping around to
* 2^64-1, and then walking off the end of the fallback area and
* eventually causing a page fault which is fatal. Just default to
* something vaguely sane.
*/
if (!l1d_size)
l1d_size = (64 * 1024);
limit = min(ppc64_bolted_size(), ppc64_rma_size);
/*
* Align to L1d size, and size it at 2x L1d size, to catch possible
* hardware prefetch runoff. We don't have a recipe for load patterns to
* reliably avoid the prefetcher.
*/
l1d_flush_fallback_area = memblock_alloc_try_nid(l1d_size * 2,
l1d_size, MEMBLOCK_LOW_LIMIT,
limit, NUMA_NO_NODE);
if (!l1d_flush_fallback_area)
panic("%s: Failed to allocate %llu bytes align=0x%llx max_addr=%pa\n",
__func__, l1d_size * 2, l1d_size, &limit);
for_each_possible_cpu(cpu) {
struct paca_struct *paca = paca_ptrs[cpu];
paca->rfi_flush_fallback_area = l1d_flush_fallback_area;
paca->l1d_flush_size = l1d_size;
}
}
void setup_rfi_flush(enum l1d_flush_type types, bool enable)
{
if (types & L1D_FLUSH_FALLBACK) {
pr_info("rfi-flush: fallback displacement flush available\n");
init_fallback_flush();
}
if (types & L1D_FLUSH_ORI)
pr_info("rfi-flush: ori type flush available\n");
if (types & L1D_FLUSH_MTTRIG)
pr_info("rfi-flush: mttrig type flush available\n");
enabled_flush_types = types;
if (!cpu_mitigations_off() && !no_rfi_flush)
rfi_flush_enable(enable);
}
void setup_entry_flush(bool enable)
{
if (cpu_mitigations_off())
return;
if (!no_entry_flush)
entry_flush_enable(enable);
}
void setup_uaccess_flush(bool enable)
{
if (cpu_mitigations_off())
return;
if (!no_uaccess_flush)
uaccess_flush_enable(enable);
}
#ifdef CONFIG_DEBUG_FS
static int count_cache_flush_set(void *data, u64 val)
{
bool enable;
if (val == 1)
enable = true;
else if (val == 0)
enable = false;
else
return -EINVAL;
toggle_branch_cache_flush(enable);
return 0;
}
static int count_cache_flush_get(void *data, u64 *val)
{
if (count_cache_flush_type == BRANCH_CACHE_FLUSH_NONE)
*val = 0;
else
*val = 1;
return 0;
}
static int link_stack_flush_get(void *data, u64 *val)
{
if (link_stack_flush_type == BRANCH_CACHE_FLUSH_NONE)
*val = 0;
else
*val = 1;
return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(fops_count_cache_flush, count_cache_flush_get,
count_cache_flush_set, "%llu\n");
DEFINE_DEBUGFS_ATTRIBUTE(fops_link_stack_flush, link_stack_flush_get,
count_cache_flush_set, "%llu\n");
static __init int count_cache_flush_debugfs_init(void)
{
debugfs_create_file_unsafe("count_cache_flush", 0600,
arch_debugfs_dir, NULL,
&fops_count_cache_flush);
debugfs_create_file_unsafe("link_stack_flush", 0600,
arch_debugfs_dir, NULL,
&fops_link_stack_flush);
return 0;
}
device_initcall(count_cache_flush_debugfs_init);
static int rfi_flush_set(void *data, u64 val)
{
bool enable;
if (val == 1)
enable = true;
else if (val == 0)
enable = false;
else
return -EINVAL;
/* Only do anything if we're changing state */
if (enable != rfi_flush)
rfi_flush_enable(enable);
return 0;
}
static int rfi_flush_get(void *data, u64 *val)
{
*val = rfi_flush ? 1 : 0;
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(fops_rfi_flush, rfi_flush_get, rfi_flush_set, "%llu\n");
static int entry_flush_set(void *data, u64 val)
{
bool enable;
if (val == 1)
enable = true;
else if (val == 0)
enable = false;
else
return -EINVAL;
/* Only do anything if we're changing state */
if (enable != entry_flush)
entry_flush_enable(enable);
return 0;
}
static int entry_flush_get(void *data, u64 *val)
{
*val = entry_flush ? 1 : 0;
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(fops_entry_flush, entry_flush_get, entry_flush_set, "%llu\n");
static int uaccess_flush_set(void *data, u64 val)
{
bool enable;
if (val == 1)
enable = true;
else if (val == 0)
enable = false;
else
return -EINVAL;
/* Only do anything if we're changing state */
if (enable != uaccess_flush)
uaccess_flush_enable(enable);
return 0;
}
static int uaccess_flush_get(void *data, u64 *val)
{
*val = uaccess_flush ? 1 : 0;
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(fops_uaccess_flush, uaccess_flush_get, uaccess_flush_set, "%llu\n");
static __init int rfi_flush_debugfs_init(void)
{
debugfs_create_file("rfi_flush", 0600, arch_debugfs_dir, NULL, &fops_rfi_flush);
debugfs_create_file("entry_flush", 0600, arch_debugfs_dir, NULL, &fops_entry_flush);
debugfs_create_file("uaccess_flush", 0600, arch_debugfs_dir, NULL, &fops_uaccess_flush);
return 0;
}
device_initcall(rfi_flush_debugfs_init);
#endif /* CONFIG_DEBUG_FS */
#endif /* CONFIG_PPC_BOOK3S_64 */
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