Commit 968c4fcc authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/signal32: Isolate non-copy actions in save_user_regs() and save_tm_user_regs() 



Reorder actions in save_user_regs() and save_tm_user_regs() to
regroup copies together in order to switch to user_access_begin()
logic in a later patch.

Move non-copy actions into new functions called
prepare_save_user_regs() and prepare_save_tm_user_regs().

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f6eac65781b4a57220477c8864bca2b57f29a5d5.1597770847.git.christophe.leroy@csgroup.eu
parent b3484a1d

arch/powerpc/kernel/signal_32.c

+41 −13
Original line number Diff line number Diff line
@@ -229,14 +229,31 @@ struct rt_sigframe { 
 * We only save the altivec/spe registers if the process has used

 * altivec/spe instructions at some point.

 */

static void prepare_save_user_regs(int ctx_has_vsx_region)

{

	/* Make sure floating point registers are stored in regs */

	flush_fp_to_thread(current);

#ifdef CONFIG_ALTIVEC

	if (current->thread.used_vr)

		flush_altivec_to_thread(current);

	if (cpu_has_feature(CPU_FTR_ALTIVEC))

		current->thread.vrsave = mfspr(SPRN_VRSAVE);

#endif

#ifdef CONFIG_VSX

	if (current->thread.used_vsr && ctx_has_vsx_region)

		flush_vsx_to_thread(current);

#endif

#ifdef CONFIG_SPE

	if (current->thread.used_spe)

		flush_spe_to_thread(current);

#endif

}



static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,

			  struct mcontext __user *tm_frame, int ctx_has_vsx_region)

{

	unsigned long msr = regs->msr;



	/* Make sure floating point registers are stored in regs */

	flush_fp_to_thread(current);



	/* save general registers */

	if (save_general_regs(regs, frame))

		return 1;
@@ -244,7 +261,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, 
#ifdef CONFIG_ALTIVEC

	/* save altivec registers */

	if (current->thread.used_vr) {

		flush_altivec_to_thread(current);

		if (__copy_to_user(&frame->mc_vregs, &current->thread.vr_state,

				   ELF_NVRREG * sizeof(vector128)))

			return 1;
@@ -260,8 +276,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, 
	 * most significant bits of that same vector. --BenH

	 * Note that the current VRSAVE value is in the SPR at this point.

	 */

	if (cpu_has_feature(CPU_FTR_ALTIVEC))

		current->thread.vrsave = mfspr(SPRN_VRSAVE);

	if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))

		return 1;

#endif /* CONFIG_ALTIVEC */
@@ -281,7 +295,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, 
	 * contains valid data

	 */

	if (current->thread.used_vsr && ctx_has_vsx_region) {

		flush_vsx_to_thread(current);

		if (copy_vsx_to_user(&frame->mc_vsregs, current))

			return 1;

		msr |= MSR_VSX;
@@ -290,7 +303,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, 
#ifdef CONFIG_SPE

	/* save spe registers */

	if (current->thread.used_spe) {

		flush_spe_to_thread(current);

		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,

				   ELF_NEVRREG * sizeof(u32)))

			return 1;
@@ -326,11 +338,23 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, 
 *

 * See save_user_regs() and signal_64.c:setup_tm_sigcontexts().

 */

static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,

			     struct mcontext __user *tm_frame, unsigned long msr)

static void prepare_save_tm_user_regs(void)

{

	WARN_ON(tm_suspend_disabled);



#ifdef CONFIG_ALTIVEC

	if (cpu_has_feature(CPU_FTR_ALTIVEC))

		current->thread.ckvrsave = mfspr(SPRN_VRSAVE);

#endif

#ifdef CONFIG_SPE

	if (current->thread.used_spe)

		flush_spe_to_thread(current);

#endif

}



static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,

			     struct mcontext __user *tm_frame, unsigned long msr)

{

	/* Save both sets of general registers */

	if (save_general_regs(&current->thread.ckpt_regs, frame)

	    || save_general_regs(regs, tm_frame))
@@ -374,8 +398,6 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame 
	 * significant bits of a vector, we "cheat" and stuff VRSAVE in the

	 * most significant bits of that same vector. --BenH

	 */

	if (cpu_has_feature(CPU_FTR_ALTIVEC))

		current->thread.ckvrsave = mfspr(SPRN_VRSAVE);

	if (__put_user(current->thread.ckvrsave,

		       (u32 __user *)&frame->mc_vregs[32]))

		return 1;
@@ -427,7 +449,6 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame 
	 * simply the same as in save_user_regs().

	 */

	if (current->thread.used_spe) {

		flush_spe_to_thread(current);

		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,

				   ELF_NEVRREG * sizeof(u32)))

			return 1;
@@ -447,6 +468,8 @@ static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame 
	return 0;

}

#else

static void prepare_save_tm_user_regs(void) { }



static int save_tm_user_regs(struct pt_regs *regs, struct mcontext __user *frame,

			     struct mcontext __user *tm_frame, unsigned long msr)

{
@@ -790,9 +813,11 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, 
		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));



	if (MSR_TM_ACTIVE(msr)) {

		prepare_save_tm_user_regs();

		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))

			goto badframe;

	} else {

		prepare_save_user_regs(1);

		if (save_user_regs(regs, mctx, tm_mctx, 1))

			goto badframe;

	}
@@ -881,9 +906,11 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, 
		flush_icache_range(tramp, tramp + 2 * sizeof(unsigned long));



	if (MSR_TM_ACTIVE(msr)) {

		prepare_save_tm_user_regs();

		if (save_tm_user_regs(regs, mctx, tm_mctx, msr))

			goto badframe;

	} else {

		prepare_save_user_regs(1);

		if (save_user_regs(regs, mctx, tm_mctx, 1))

			goto badframe;

	}
@@ -1038,6 +1065,7 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, 
		 */

		mctx = (struct mcontext __user *)

			((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);

		prepare_save_user_regs(ctx_has_vsx_region);

		if (save_user_regs(regs, mctx, NULL, ctx_has_vsx_region))

			return -EFAULT;

		if (!user_write_access_begin(old_ctx, ctx_size))