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Diffstat (limited to 'arch/arm64/kernel/armv8_deprecated.c')
-rw-r--r--arch/arm64/kernel/armv8_deprecated.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index bcb14d11232f..12b545f7fb32 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -59,6 +59,7 @@ struct insn_emulation {
static LIST_HEAD(insn_emulation);
static int nr_insn_emulated __initdata;
static DEFINE_RAW_SPINLOCK(insn_emulation_lock);
+static DEFINE_MUTEX(insn_emulation_mutex);
static void register_emulation_hooks(struct insn_emulation_ops *ops)
{
@@ -207,10 +208,12 @@ static int emulation_proc_handler(struct ctl_table *table, int write,
loff_t *ppos)
{
int ret = 0;
- struct insn_emulation *insn = (struct insn_emulation *) table->data;
- enum insn_emulation_mode prev_mode = insn->current_mode;
+ struct insn_emulation *insn;
+ enum insn_emulation_mode prev_mode;
- table->data = &insn->current_mode;
+ mutex_lock(&insn_emulation_mutex);
+ insn = container_of(table->data, struct insn_emulation, current_mode);
+ prev_mode = insn->current_mode;
ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (ret || !write || prev_mode == insn->current_mode)
@@ -223,7 +226,7 @@ static int emulation_proc_handler(struct ctl_table *table, int write,
update_insn_emulation_mode(insn, INSN_UNDEF);
}
ret:
- table->data = insn;
+ mutex_unlock(&insn_emulation_mutex);
return ret;
}
@@ -247,7 +250,7 @@ static void __init register_insn_emulation_sysctl(void)
sysctl->maxlen = sizeof(int);
sysctl->procname = insn->ops->name;
- sysctl->data = insn;
+ sysctl->data = &insn->current_mode;
sysctl->extra1 = &insn->min;
sysctl->extra2 = &insn->max;
sysctl->proc_handler = emulation_proc_handler;