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selftests/x86/mpx: Fix incorrect bounds with old _sigfault 

For distributions with old userspace header files, the _sigfault
structure is different. mpx-mini-test fails with the following
error:

  [root@Purley]# mpx-mini-test_64 tabletest
  XSAVE is supported by HW & OS
  XSAVE processor supported state mask: 0x2ff
  XSAVE OS supported state mask: 0x2ff
   BNDREGS: size: 64 user: 1 supervisor: 0 aligned: 0
    BNDCSR: size: 64 user: 1 supervisor: 0 aligned: 0
  starting mpx bounds table test
  ERROR: siginfo bounds do not match shadow bounds for register 0

Fix it by using the correct offset of _lower/_upper in _sigfault.
RHEL needs this patch to work.

Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave.hansen@linux.intel.com
Fixes: e754aedc26 ("x86/mpx, selftests: Add MPX self test")
Link: http://lkml.kernel.org/r/1513586050-1641-1-git-send-email-rui.y.wang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
zero-colors
Rui Wang 2017-12-18 16:34:10 +08:00 committed by Ingo Molnar
parent 1299ef1d88
commit 961888b1d7
1 changed files with 30 additions and 2 deletions
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32
tools/testing/selftests/x86/mpx-mini-test.c
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@ -315,11 +315,39 @@ static inline void *__si_bounds_upper(siginfo_t *si)
return si->si_upper;
}
#else
/*
* This deals with old version of _sigfault in some distros:
*
old _sigfault:
struct {
void *si_addr;
} _sigfault;
new _sigfault:
struct {
void __user *_addr;
int _trapno;
short _addr_lsb;
union {
struct {
void __user *_lower;
void __user *_upper;
} _addr_bnd;
__u32 _pkey;
};
} _sigfault;
*
*/
static inline void **__si_bounds_hack(siginfo_t *si)
{
void *sigfault = &si->_sifields._sigfault;
void *end_sigfault = sigfault + sizeof(si->_sifields._sigfault);
void **__si_lower = end_sigfault;
int *trapno = (int*)end_sigfault;
/* skip _trapno and _addr_lsb */
void **__si_lower = (void**)(trapno + 2);
return __si_lower;
}
@ -331,7 +359,7 @@ static inline void *__si_bounds_lower(siginfo_t *si)
static inline void *__si_bounds_upper(siginfo_t *si)
{
return (*__si_bounds_hack(si)) + sizeof(void *);
return *(__si_bounds_hack(si) + 1);
}
#endif