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Commit 961888b1 authored by Rui Wang's avatar Rui Wang Committed by Ingo Molnar
Browse files

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: default avatarRui 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: e754aedc ("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: default avatarIngo Molnar <mingo@kernel.org>
parent 1299ef1d

tools/testing/selftests/x86/mpx-mini-test.c

+30 −2
Original line number Diff line number Diff line
@@ -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