[PATCH] x86/paravirt: Cleanup native_patch()

From: Borislav Petkov
Date: Sat Sep 08 2018 - 11:28:13 EST


When CONFIG_PARAVIRT_SPINLOCKS=n, it fires

arch/x86/kernel/paravirt_patch_64.c: In function ânative_patchâ:
arch/x86/kernel/paravirt_patch_64.c:89:1: warning: label âpatch_siteâ 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@xxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
---

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.

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