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authorBorislav Petkov <bp@suse.de>2016-02-10 15:51:16 +0100
committerBen Hutchings <ben@decadent.org.uk>2018-01-07 01:46:46 +0000
commit6f498371e64cd1d0bc04ed66867ef04c80950e1a (patch)
tree487b4a5d2e7fff98bf70a07d8f62b5d4bec57003
parent5a2615f13d1f643f53d66bf166bcaad42d3a28a3 (diff)
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x86/mm: Fix INVPCID asm constraint
commit e2c7698cd61f11d4077fdb28148b2d31b82ac848 upstream. So we want to specify the dependency on both @pcid and @addr so that the compiler doesn't reorder accesses to them *before* the TLB flush. But for that to work, we need to express this properly in the inline asm and deref the whole desc array, not the pointer to it. See clwb() for an example. This fixes the build error on 32-bit: arch/x86/include/asm/tlbflush.h: In function ‘__invpcid’: arch/x86/include/asm/tlbflush.h:26:18: error: memory input 0 is not directly addressable which gcc4.7 caught but 5.x didn't. Which is strange. :-\ Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Michael Matz <matz@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--arch/x86/include/asm/tlbflush.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 22089098e4fd..24bf6a3b2948 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -10,7 +10,7 @@
static inline void __invpcid(unsigned long pcid, unsigned long addr,
unsigned long type)
{
- u64 desc[2] = { pcid, addr };
+ struct { u64 d[2]; } desc = { { pcid, addr } };
/*
* The memory clobber is because the whole point is to invalidate
@@ -22,7 +22,7 @@ static inline void __invpcid(unsigned long pcid, unsigned long addr,
* invpcid (%rcx), %rax in long mode.
*/
asm volatile (".byte 0x66, 0x0f, 0x38, 0x82, 0x01"
- : : "m" (desc), "a" (type), "c" (desc) : "memory");
+ : : "m" (desc), "a" (type), "c" (&desc) : "memory");
}
#define INVPCID_TYPE_INDIV_ADDR 0