x86/mm/cpa: Fix cpa_flush_array() TLB invalidation

In commit:

  a7295fd53c39 ("x86/mm/cpa: Use flush_tlb_kernel_range()")

I misread the CAP array code and incorrectly used
tlb_flush_kernel_range(), resulting in missing TLB flushes and
consequent failures.

Instead do a full invalidate in this case -- for now.

Reported-by: StDenis, Tom <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Fixes: a7295fd53c39 ("x86/mm/cpa: Use flush_tlb_kernel_range()")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 16 insertions, 8 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index db7a10082238..a1bcde35db4c 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -285,20 +285,16 @@ static void cpa_flush_all(unsigned long cache)
 	on_each_cpu(__cpa_flush_all, (void *) cache, 1);
 }
 
-static bool __cpa_flush_range(unsigned long start, int numpages, int cache)
+static bool __inv_flush_all(int cache)
 {
 	BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
 
-	WARN_ON(PAGE_ALIGN(start) != start);
-
 	if (cache && !static_cpu_has(X86_FEATURE_CLFLUSH)) {
 		cpa_flush_all(cache);
 		return true;
 	}
 
-	flush_tlb_kernel_range(start, start + PAGE_SIZE * numpages);
-
-	return !cache;
+	return false;
 }
 
 static void cpa_flush_range(unsigned long start, int numpages, int cache)
@@ -306,7 +302,14 @@ static void cpa_flush_range(unsigned long start, int numpages, int cache)
 	unsigned int i, level;
 	unsigned long addr;
 
-	if (__cpa_flush_range(start, numpages, cache))
+	WARN_ON(PAGE_ALIGN(start) != start);
+
+	if (__inv_flush_all(cache))
+		return;
+
+	flush_tlb_kernel_range(start, start + PAGE_SIZE * numpages);
+
+	if (!cache)
 		return;
 
 	/*
@@ -332,7 +335,12 @@ static void cpa_flush_array(unsigned long baddr, unsigned long *start,
 {
 	unsigned int i, level;
 
-	if (__cpa_flush_range(baddr, numpages, cache))
+	if (__inv_flush_all(cache))
+		return;
+
+	flush_tlb_all();
+
+	if (!cache)
 		return;
 
 	/*