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Message-Id: <f6eac65781b4a57220477c8864bca2b57f29a5d5.1597770847.git.christophe.leroy@csgroup.eu>
Date: Tue, 18 Aug 2020 17:19:36 +0000 (UTC)
From: Christophe Leroy <christophe.leroy@...roup.eu>
To: Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
Michael Ellerman <mpe@...erman.id.au>
Cc: linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH v2 24/25] 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: Christophe Leroy <christophe.leroy@...roup.eu>
---
arch/powerpc/kernel/signal_32.c | 54 +++++++++++++++++++++++++--------
1 file changed, 41 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 5b8a4ede142c..86539a4e0514 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -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, ¤t->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(¤t->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))
--
2.25.0
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