Commit e2c7698c authored by Borislav Petkov's avatar Borislav Petkov Committed by Ingo Molnar

x86/mm: Fix INVPCID asm constraint

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: default avatarBorislav 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: default avatarIngo Molnar <mingo@kernel.org>
parent ce1143aa
...@@ -10,7 +10,7 @@ ...@@ -10,7 +10,7 @@
static inline void __invpcid(unsigned long pcid, unsigned long addr, static inline void __invpcid(unsigned long pcid, unsigned long addr,
unsigned long type) 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 * 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, ...@@ -22,7 +22,7 @@ static inline void __invpcid(unsigned long pcid, unsigned long addr,
* invpcid (%rcx), %rax in long mode. * invpcid (%rcx), %rax in long mode.
*/ */
asm volatile (".byte 0x66, 0x0f, 0x38, 0x82, 0x01" 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 #define INVPCID_TYPE_INDIV_ADDR 0
......
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