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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 v2] x86/paravirt: Cleanup native_patch()
Date: Tue, 11 Sep 2018 11:15:10 +0200	[thread overview]
Message-ID: <20180911091510.GA12094@zn.tnic> (raw)
In-Reply-To: <dfe856d6-a4db-b406-ef18-dba3b6b8c342@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. Also, simplify function
flow for better readability.

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

Here it is, rebased ontop of rc3+tip/master.


 arch/x86/kernel/paravirt_patch_32.c | 44 ++++++++++-----------------
 arch/x86/kernel/paravirt_patch_64.c | 46 +++++++++++------------------
 2 files changed, 33 insertions(+), 57 deletions(-)

diff --git a/arch/x86/kernel/paravirt_patch_32.c b/arch/x86/kernel/paravirt_patch_32.c
index d460cbcabcfe..6368c22fa1fa 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 +50,24 @@ 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);
+		break;
 
-		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);
+		break;
 #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;
 	}
 #undef PATCH_SITE
-	return ret;
+	return paravirt_patch_default(type, ibuf, addr, len);
 }
diff --git a/arch/x86/kernel/paravirt_patch_64.c b/arch/x86/kernel/paravirt_patch_64.c
index 5ad5bcda9dc6..7ca9cb726f4d 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 +60,24 @@ 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);
+		break;
 
-		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);
+		break;
 #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;
 	}
 #undef PATCH_SITE
-	return ret;
+	return paravirt_patch_default(type, ibuf, addr, len);
 }
-- 
2.17.0.582.gccdcbd54c

-- 
Regards/Gruss,
    Boris.

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

  reply	other threads:[~2018-09-11  9:15 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       ` [PATCH] x86/paravirt: Cleanup native_patch() Borislav Petkov
2018-09-10  6:54         ` Juergen Gross
2018-09-10  7:01           ` Borislav Petkov
2018-09-10  8:33             ` Juergen Gross
2018-09-11  9:15               ` Borislav Petkov [this message]
2018-09-11  9:44                 ` [PATCH v2] " 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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