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From: Borislav Petkov <bp@alien8.de>
To: Juergen Gross <jgross@suse.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
	x86@kernel.org, virtualization@lists.linux-foundation.org
Subject: [PATCH] x86/paravirt: Cleanup native_patch()
Date: Sat, 8 Sep 2018 17:28:00 +0200	[thread overview]
Message-ID: <20180908152800.GA8286@zn.tnic> (raw)
In-Reply-To: <65bb69fa-855f-9efc-19ba-c0fab69f468c@suse.com>

When CONFIG_PARAVIRT_SPINLOCKS=n, it fires

  arch/x86/kernel/paravirt_patch_64.c: In function ‘native_patch’:
  arch/x86/kernel/paravirt_patch_64.c:89:1: warning: label ‘patch_site’ defined but not used [-Wunused-label]
   patch_site:

but those labels can simply be removed by directly calling the
respective functions there.

Get rid of local variables too, while at it.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: x86@kernel.org
Cc: virtualization@lists.linux-foundation.org
---

It looks even more cleaner now. :)

 arch/x86/kernel/paravirt_patch_32.c | 48 +++++++++++-----------------
 arch/x86/kernel/paravirt_patch_64.c | 49 ++++++++++++-----------------
 2 files changed, 39 insertions(+), 58 deletions(-)

diff --git a/arch/x86/kernel/paravirt_patch_32.c b/arch/x86/kernel/paravirt_patch_32.c
index d460cbcabcfe..0865323c2716 100644
--- a/arch/x86/kernel/paravirt_patch_32.c
+++ b/arch/x86/kernel/paravirt_patch_32.c
@@ -34,14 +34,10 @@ extern bool pv_is_native_vcpu_is_preempted(void);
 
 unsigned native_patch(u8 type, void *ibuf, unsigned long addr, unsigned len)
 {
-	const unsigned char *start, *end;
-	unsigned ret;
-
 #define PATCH_SITE(ops, x)					\
-		case PARAVIRT_PATCH(ops.x):			\
-			start = start_##ops##_##x;		\
-			end = end_##ops##_##x;			\
-			goto patch_site
+	case PARAVIRT_PATCH(ops.x):				\
+		return paravirt_patch_insns(ibuf, len, start_##ops##_##x, end_##ops##_##x)
+
 	switch (type) {
 #ifdef CONFIG_PARAVIRT_XXL
 		PATCH_SITE(irq, irq_disable);
@@ -54,32 +50,26 @@ unsigned native_patch(u8 type, void *ibuf, unsigned long addr, unsigned len)
 		PATCH_SITE(mmu, write_cr3);
 #endif
 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
-		case PARAVIRT_PATCH(lock.queued_spin_unlock):
-			if (pv_is_native_spin_unlock()) {
-				start = start_lock_queued_spin_unlock;
-				end   = end_lock_queued_spin_unlock;
-				goto patch_site;
-			}
-			goto patch_default;
+	case PARAVIRT_PATCH(lock.queued_spin_unlock):
+		if (pv_is_native_spin_unlock())
+			return paravirt_patch_insns(ibuf, len,
+						    start_lock_queued_spin_unlock,
+						    end_lock_queued_spin_unlock);
+		else
+			return paravirt_patch_default(type, ibuf, addr, len);
 
-		case PARAVIRT_PATCH(lock.vcpu_is_preempted):
-			if (pv_is_native_vcpu_is_preempted()) {
-				start = start_lock_vcpu_is_preempted;
-				end   = end_lock_vcpu_is_preempted;
-				goto patch_site;
-			}
-			goto patch_default;
+	case PARAVIRT_PATCH(lock.vcpu_is_preempted):
+		if (pv_is_native_vcpu_is_preempted())
+			return paravirt_patch_insns(ibuf, len,
+						    start_lock_vcpu_is_preempted,
+						    end_lock_vcpu_is_preempted);
+		else
+			return paravirt_patch_default(type, ibuf, addr, len);
 #endif
 
 	default:
-patch_default: __maybe_unused
-		ret = paravirt_patch_default(type, ibuf, addr, len);
-		break;
-
-patch_site:
-		ret = paravirt_patch_insns(ibuf, len, start, end);
-		break;
+		return paravirt_patch_default(type, ibuf, addr, len);
 	}
 #undef PATCH_SITE
-	return ret;
+	return 0;
 }
diff --git a/arch/x86/kernel/paravirt_patch_64.c b/arch/x86/kernel/paravirt_patch_64.c
index 5ad5bcda9dc6..3549f5f9d685 100644
--- a/arch/x86/kernel/paravirt_patch_64.c
+++ b/arch/x86/kernel/paravirt_patch_64.c
@@ -42,15 +42,11 @@ extern bool pv_is_native_vcpu_is_preempted(void);
 
 unsigned native_patch(u8 type, void *ibuf, unsigned long addr, unsigned len)
 {
-	const unsigned char *start, *end;
-	unsigned ret;
-
 #define PATCH_SITE(ops, x)					\
-		case PARAVIRT_PATCH(ops.x):			\
-			start = start_##ops##_##x;		\
-			end = end_##ops##_##x;			\
-			goto patch_site
-	switch(type) {
+	case PARAVIRT_PATCH(ops.x):				\
+		return paravirt_patch_insns(ibuf, len, start_##ops##_##x, end_##ops##_##x)
+
+	switch (type) {
 #ifdef CONFIG_PARAVIRT_XXL
 		PATCH_SITE(irq, restore_fl);
 		PATCH_SITE(irq, save_fl);
@@ -64,32 +60,27 @@ unsigned native_patch(u8 type, void *ibuf, unsigned long addr, unsigned len)
 		PATCH_SITE(mmu, write_cr3);
 #endif
 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
-		case PARAVIRT_PATCH(lock.queued_spin_unlock):
-			if (pv_is_native_spin_unlock()) {
-				start = start_lock_queued_spin_unlock;
-				end   = end_lock_queued_spin_unlock;
-				goto patch_site;
-			}
-			goto patch_default;
+	case PARAVIRT_PATCH(lock.queued_spin_unlock):
+		if (pv_is_native_spin_unlock())
+			return paravirt_patch_insns(ibuf, len,
+						    start_lock_queued_spin_unlock,
+						    end_lock_queued_spin_unlock);
+		else
+			return paravirt_patch_default(type, ibuf, addr, len);
 
-		case PARAVIRT_PATCH(lock.vcpu_is_preempted):
-			if (pv_is_native_vcpu_is_preempted()) {
-				start = start_lock_vcpu_is_preempted;
-				end   = end_lock_vcpu_is_preempted;
-				goto patch_site;
-			}
-			goto patch_default;
+	case PARAVIRT_PATCH(lock.vcpu_is_preempted):
+		if (pv_is_native_vcpu_is_preempted())
+			return paravirt_patch_insns(ibuf, len,
+						    start_lock_vcpu_is_preempted,
+						    end_lock_vcpu_is_preempted);
+		else
+			return paravirt_patch_default(type, ibuf, addr, len);
 #endif
 
 	default:
-patch_default: __maybe_unused
-		ret = paravirt_patch_default(type, ibuf, addr, len);
-		break;
-
-patch_site:
-		ret = paravirt_patch_insns(ibuf, len, start, end);
+		return paravirt_patch_default(type, ibuf, addr, len);
 		break;
 	}
 #undef PATCH_SITE
-	return ret;
+	return 0;
 }
-- 
2.17.0.582.gccdcbd54c


-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

  reply	other threads:[~2018-09-08 15:28 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-07 10:49 [PATCH] x86/paravirt: Get rid of patch_site label Borislav Petkov
2018-09-07 10:51 ` Borislav Petkov
2018-09-07 20:10   ` [PATCH v2] x86/paravirt: Get rid of patch_site and patch_default labels Borislav Petkov
2018-09-08  5:45     ` Juergen Gross
2018-09-08 15:28       ` Borislav Petkov [this message]
2018-09-10  6:54         ` [PATCH] x86/paravirt: Cleanup native_patch() Juergen Gross
2018-09-10  7:01           ` Borislav Petkov
2018-09-10  8:33             ` Juergen Gross
2018-09-11  9:15               ` [PATCH v2] " Borislav Petkov
2018-09-11  9:44                 ` Juergen Gross
2018-09-11 15:34                 ` [tip:x86/paravirt] x86/paravirt: Clean up native_patch() tip-bot for Borislav Petkov

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