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| author | Andy Lutomirski <luto@kernel.org> | 2017-08-15 08:36:19 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-08-15 11:10:58 +0300 |
| commit | fa2016a8e7d846b306e431646d250500e1da0c33 (patch) | |
| tree | c3fb53e1173b7e2dacfd7b9f4b04d29fd5845b33 /tools | |
| parent | bf4d1a83758368c842c94cab9661a75ca98bc848 (diff) | |
| download | linux-fa2016a8e7d846b306e431646d250500e1da0c33.tar.xz | |
x86/xen/64: Fix the reported SS and CS in SYSCALL
When I cleaned up the Xen SYSCALL entries, I inadvertently changed
the reported segment registers. Before my patch, regs->ss was
__USER(32)_DS and regs->cs was __USER(32)_CS. After the patch, they
are FLAT_USER_CS/DS(32).
This had a couple unfortunate effects. It confused the
opportunistic fast return logic. It also significantly increased
the risk of triggering a nasty glibc bug:
https://sourceware.org/bugzilla/show_bug.cgi?id=21269
Update the Xen entry code to change it back.
Reported-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Fixes: 8a9949bc71a7 ("x86/xen/64: Rearrange the SYSCALL entries")
Link: http://lkml.kernel.org/r/daba8351ea2764bb30272296ab9ce08a81bd8264.1502775273.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools')
0 files changed, 0 insertions, 0 deletions