This is a note to let you know that I've just added the patch titled
selftests/x86/mpx: Fix incorrect bounds with old _sigfault
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
selftests-x86-mpx-fix-incorrect-bounds-with-old-_sigfault.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 961888b1d76d84efc66a8f5604b06ac12ac2f978 Mon Sep 17 00:00:00 2001
From: Rui Wang <rui.y.wang@xxxxxxxxx>
Date: Mon, 18 Dec 2017 16:34:10 +0800
Subject: selftests/x86/mpx: Fix incorrect bounds with old _sigfault
From: Rui Wang <rui.y.wang@xxxxxxxxx>
commit 961888b1d76d84efc66a8f5604b06ac12ac2f978 upstream.
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@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: dave.hansen@xxxxxxxxxxxxxxx
Fixes: e754aedc26ef ("x86/mpx, selftests: Add MPX self test")
Link: http://lkml.kernel.org/r/1513586050-1641-1-git-send-email-rui.y.wang@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/x86/mpx-mini-test.c | 32 ++++++++++++++++++++++++++--
1 file changed, 30 insertions(+), 2 deletions(-)
--- a/tools/testing/selftests/x86/mpx-mini-test.c
+++ b/tools/testing/selftests/x86/mpx-mini-test.c
@@ -315,11 +315,39 @@ static inline void *__si_bounds_upper(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(si
static inline void *__si_bounds_upper(siginfo_t *si)
{
- return (*__si_bounds_hack(si)) + sizeof(void *);
+ return *(__si_bounds_hack(si) + 1);
}
#endif
Patches currently in stable-queue which might be from rui.y.wang@xxxxxxxxx are
queue-4.9/selftests-x86-mpx-fix-incorrect-bounds-with-old-_sigfault.patch