[PATCH 4.9 119/148] x86/mpx/selftests: Fix up weird arrays

Greg Kroah-Hartman
2017-12-12T13:01:36Z

From: Dave Hansen <dave.hansen@linux.intel.com>

[ Upstream commit a6400120d042397675fcf694060779d21e9e762d ]

The MPX hardware data structurse are defined in a weird way: they define
their size in bytes and then union that with the type with which we want
to access them.

Yes, this is weird, but it does work. But, new GCC's complain that we
are accessing the array out of bounds. Just make it a zero-sized array
so gcc will stop complaining. There was not really a bug here.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20171111001229.58A7933D@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/testing/selftests/x86/mpx-hw.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/tools/testing/selftests/x86/mpx-hw.h
+++ b/tools/testing/selftests/x86/mpx-hw.h
@@ -51,14 +51,14 @@
struct mpx_bd_entry {
union {
char x[MPX_BOUNDS_DIR_ENTRY_SIZE_BYTES];
- void *contents[1];
+ void *contents[0];
};
} __attribute__((packed));

struct mpx_bt_entry {
union {
char x[MPX_BOUNDS_TABLE_ENTRY_SIZE_BYTES];
- unsigned long contents[1];
+ unsigned long contents[0];
};
} __attribute__((packed));