Commit d4ddefee authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux 

Pull arm64 fixes from Catalin Marinas:
 "Two more SME fixes related to ptrace(): ensure that the SME is
  properly set up for the target thread and that the thread sees
  the ZT registers set via ptrace"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64/ptrace: Ensure that the task sees ZT writes on first use
  arm64/ptrace: Ensure that SME is set up for target when writing SSVE state
parents 3e13eee1 2f43f549

arch/arm64/include/asm/fpsimd.h

+2 −2
Original line number Diff line number Diff line
@@ -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; }

arch/arm64/kernel/fpsimd.c

+3 −3
Original line number Diff line number Diff line
@@ -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;

arch/arm64/kernel/ptrace.c

+17 −3
Original line number Diff line number Diff line
@@ -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;
@@ -1170,8 +1177,13 @@ static int zt_set(struct task_struct *target, 
	if (!system_supports_sme2())

		return -EINVAL;



	/* Ensure SVE storage in case this is first use of SME */

	sve_alloc(target, false);

	if (!target->thread.sve_state)

		return -ENOMEM;



	if (!thread_za_enabled(&target->thread)) {

		sme_alloc(target);

		sme_alloc(target, true);

		if (!target->thread.sme_state)

			return -ENOMEM;

	}
@@ -1179,8 +1191,10 @@ static int zt_set(struct task_struct *target, 
	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,

				 thread_zt_state(&target->thread),

				 0, ZT_SIG_REG_BYTES);

	if (ret == 0)

	if (ret == 0) {

		target->thread.svcr |= SVCR_ZA_MASK;

		set_tsk_thread_flag(target, TIF_SME);

	}



	fpsimd_flush_task_state(target);

arch/arm64/kernel/signal.c

+1 −1
Original line number Diff line number Diff line
@@ -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);