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powerpc/security: re-name count cache flush to branch cache flush

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The count cache flush mostly refers to both count cache and link stack
flushing. As a first step to untangling these a bit, re-name the bits
that apply to both.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200609070610.846703-2-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2020-06-09 17:06:04 +10:00 committed by Michael Ellerman
parent b2b46304e9
commit 1026798c64
3 changed files with 23 additions and 24 deletions
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4
arch/powerpc/include/asm/asm-prototypes.h
View File

@ -144,13 +144,13 @@ void _kvmppc_restore_tm_pr(struct kvm_vcpu *vcpu, u64 guest_msr);
void _kvmppc_save_tm_pr(struct kvm_vcpu *vcpu, u64 guest_msr);
/* Patch sites */
extern s32 patch__call_flush_count_cache;
extern s32 patch__call_flush_branch_caches;
extern s32 patch__flush_count_cache_return;
extern s32 patch__flush_link_stack_return;
extern s32 patch__call_kvm_flush_link_stack;
extern s32 patch__memset_nocache, patch__memcpy_nocache;
extern long flush_count_cache;
extern long flush_branch_caches;
extern long kvm_flush_link_stack;
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

7
arch/powerpc/kernel/entry_64.S
View File

@ -259,8 +259,7 @@ _ASM_NOKPROBE_SYMBOL(save_nvgprs);
#define FLUSH_COUNT_CACHE \
1: nop; \
patch_site 1b, patch__call_flush_count_cache
patch_site 1b, patch__call_flush_branch_caches
#define BCCTR_FLUSH .long 0x4c400420
@ -271,8 +270,8 @@ _ASM_NOKPROBE_SYMBOL(save_nvgprs);
.endm
.balign 32
.global flush_count_cache
flush_count_cache:
.global flush_branch_caches
flush_branch_caches:
/* Save LR into r9 */
mflr r9

36
arch/powerpc/kernel/security.c
View File

@ -21,12 +21,12 @@
u64 powerpc_security_features __read_mostly = SEC_FTR_DEFAULT;
enum count_cache_flush_type {
COUNT_CACHE_FLUSH_NONE = 0x1,
COUNT_CACHE_FLUSH_SW = 0x2,
COUNT_CACHE_FLUSH_HW = 0x4,
enum branch_cache_flush_type {
BRANCH_CACHE_FLUSH_NONE = 0x1,
BRANCH_CACHE_FLUSH_SW = 0x2,
BRANCH_CACHE_FLUSH_HW = 0x4,
};
static enum count_cache_flush_type count_cache_flush_type = COUNT_CACHE_FLUSH_NONE;
static enum branch_cache_flush_type count_cache_flush_type = BRANCH_CACHE_FLUSH_NONE;
static bool link_stack_flush_enabled;
bool barrier_nospec_enabled;
@ -222,10 +222,10 @@ ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, c
if (link_stack_flush_enabled)
seq_buf_printf(&s, ", Software link stack flush");
} else if (count_cache_flush_type != COUNT_CACHE_FLUSH_NONE) {
} else if (count_cache_flush_type != BRANCH_CACHE_FLUSH_NONE) {
seq_buf_printf(&s, "Mitigation: Software count cache flush");
if (count_cache_flush_type == COUNT_CACHE_FLUSH_HW)
if (count_cache_flush_type == BRANCH_CACHE_FLUSH_HW)
seq_buf_printf(&s, " (hardware accelerated)");
if (link_stack_flush_enabled)
@ -429,18 +429,18 @@ device_initcall(stf_barrier_debugfs_init);
static void no_count_cache_flush(void)
{
count_cache_flush_type = COUNT_CACHE_FLUSH_NONE;
count_cache_flush_type = BRANCH_CACHE_FLUSH_NONE;
pr_info("count-cache-flush: software flush disabled.\n");
}
static void toggle_count_cache_flush(bool enable)
static void toggle_branch_cache_flush(bool enable)
{
if (!security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE) &&
!security_ftr_enabled(SEC_FTR_FLUSH_LINK_STACK))
enable = false;
if (!enable) {
patch_instruction_site(&patch__call_flush_count_cache,
patch_instruction_site(&patch__call_flush_branch_caches,
ppc_inst(PPC_INST_NOP));
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
patch_instruction_site(&patch__call_kvm_flush_link_stack,
@ -452,9 +452,9 @@ static void toggle_count_cache_flush(bool enable)
return;
}
// This enables the branch from _switch to flush_count_cache
patch_branch_site(&patch__call_flush_count_cache,
(u64)&flush_count_cache, BRANCH_SET_LINK);
// This enables the branch from _switch to flush_branch_caches
patch_branch_site(&patch__call_flush_branch_caches,
(u64)&flush_branch_caches, BRANCH_SET_LINK);
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
// This enables the branch from guest_exit_cont to kvm_flush_link_stack
@ -474,13 +474,13 @@ static void toggle_count_cache_flush(bool enable)
}
if (!security_ftr_enabled(SEC_FTR_BCCTR_FLUSH_ASSIST)) {
count_cache_flush_type = COUNT_CACHE_FLUSH_SW;
count_cache_flush_type = BRANCH_CACHE_FLUSH_SW;
pr_info("count-cache-flush: full software flush sequence enabled.\n");
return;
}
patch_instruction_site(&patch__flush_count_cache_return, ppc_inst(PPC_INST_BLR));
count_cache_flush_type = COUNT_CACHE_FLUSH_HW;
count_cache_flush_type = BRANCH_CACHE_FLUSH_HW;
pr_info("count-cache-flush: hardware assisted flush sequence enabled\n");
}
@ -505,7 +505,7 @@ void setup_count_cache_flush(void)
security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE))
security_ftr_set(SEC_FTR_FLUSH_LINK_STACK);
toggle_count_cache_flush(enable);
toggle_branch_cache_flush(enable);
}
#ifdef CONFIG_DEBUG_FS
@ -520,14 +520,14 @@ static int count_cache_flush_set(void *data, u64 val)
else
return -EINVAL;
toggle_count_cache_flush(enable);
toggle_branch_cache_flush(enable);
return 0;
}
static int count_cache_flush_get(void *data, u64 *val)
{
if (count_cache_flush_type == COUNT_CACHE_FLUSH_NONE)
if (count_cache_flush_type == BRANCH_CACHE_FLUSH_NONE)
*val = 0;
else
*val = 1;