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-rw-r--r--arch/arm64/include/asm/fpsimd.h4
-rw-r--r--arch/arm64/kernel/fpsimd.c6
-rw-r--r--arch/arm64/kernel/ptrace.c11
-rw-r--r--arch/arm64/kernel/signal.c2
4 files changed, 15 insertions, 8 deletions
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
index 67f2fb781f59..8df46f186c64 100644
--- a/arch/arm64/include/asm/fpsimd.h
+++ b/arch/arm64/include/asm/fpsimd.h
@@ -356,7 +356,7 @@ static inline int sme_max_virtualisable_vl(void)
return vec_max_virtualisable_vl(ARM64_VEC_SME);
}
-extern void sme_alloc(struct task_struct *task);
+extern void sme_alloc(struct task_struct *task, bool flush);
extern unsigned int sme_get_vl(void);
extern int sme_set_current_vl(unsigned long arg);
extern int sme_get_current_vl(void);
@@ -388,7 +388,7 @@ static inline void sme_smstart_sm(void) { }
static inline void sme_smstop_sm(void) { }
static inline void sme_smstop(void) { }
-static inline void sme_alloc(struct task_struct *task) { }
+static inline void sme_alloc(struct task_struct *task, bool flush) { }
static inline void sme_setup(void) { }
static inline unsigned int sme_get_vl(void) { return 0; }
static inline int sme_max_vl(void) { return 0; }
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 75c37b1c55aa..087c05aa960e 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -1285,9 +1285,9 @@ void fpsimd_release_task(struct task_struct *dead_task)
* the interest of testability and predictability, the architecture
* guarantees that when ZA is enabled it will be zeroed.
*/
-void sme_alloc(struct task_struct *task)
+void sme_alloc(struct task_struct *task, bool flush)
{
- if (task->thread.sme_state) {
+ if (task->thread.sme_state && flush) {
memset(task->thread.sme_state, 0, sme_state_size(task));
return;
}
@@ -1515,7 +1515,7 @@ void do_sme_acc(unsigned long esr, struct pt_regs *regs)
}
sve_alloc(current, false);
- sme_alloc(current);
+ sme_alloc(current, true);
if (!current->thread.sve_state || !current->thread.sme_state) {
force_sig(SIGKILL);
return;
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 5b9b4305248b..a31af7a1abe3 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -881,6 +881,13 @@ static int sve_set_common(struct task_struct *target,
break;
case ARM64_VEC_SME:
target->thread.svcr |= SVCR_SM_MASK;
+
+ /*
+ * Disable traps and ensure there is SME storage but
+ * preserve any currently set values in ZA/ZT.
+ */
+ sme_alloc(target, false);
+ set_tsk_thread_flag(target, TIF_SME);
break;
default:
WARN_ON_ONCE(1);
@@ -1100,7 +1107,7 @@ static int za_set(struct task_struct *target,
}
/* Allocate/reinit ZA storage */
- sme_alloc(target);
+ sme_alloc(target, true);
if (!target->thread.sme_state) {
ret = -ENOMEM;
goto out;
@@ -1171,7 +1178,7 @@ static int zt_set(struct task_struct *target,
return -EINVAL;
if (!thread_za_enabled(&target->thread)) {
- sme_alloc(target);
+ sme_alloc(target, true);
if (!target->thread.sme_state)
return -ENOMEM;
}
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index e304f7ebec2a..c7ebe744c64e 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -475,7 +475,7 @@ static int restore_za_context(struct user_ctxs *user)
fpsimd_flush_task_state(current);
/* From now, fpsimd_thread_switch() won't touch thread.sve_state */
- sme_alloc(current);
+ sme_alloc(current, true);
if (!current->thread.sme_state) {
current->thread.svcr &= ~SVCR_ZA_MASK;
clear_thread_flag(TIF_SME);