1. 25 6月, 2015 2 次提交
    • V
      ARC: add smp barriers around atomics per Documentation/atomic_ops.txt · 2576c28e
      Vineet Gupta 提交于
       - arch_spin_lock/unlock were lacking the ACQUIRE/RELEASE barriers
         Since ARCv2 only provides load/load, store/store and all/all, we need
         the full barrier
      
       - LLOCK/SCOND based atomics, bitops, cmpxchg, which return modified
         values were lacking the explicit smp barriers.
      
       - Non LLOCK/SCOND varaints don't need the explicit barriers since that
         is implicity provided by the spin locks used to implement the
         critical section (the spin lock barriers in turn are also fixed in
         this commit as explained above
      
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: stable@vger.kernel.org
      Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
      2576c28e
    • V
      ARC: add compiler barrier to LLSC based cmpxchg · d57f7272
      Vineet Gupta 提交于
      When auditing cmpxchg call sites, Chuck noted that gcc was optimizing
      away some of the desired LDs.
      
      |	do {
      |		new = old = *ipi_data_ptr;
      |		new |= 1U << msg;
      |	} while (cmpxchg(ipi_data_ptr, old, new) != old);
      
      was generating to below
      
      | 8015cef8:	ld         r2,[r4,0]  <-- First LD
      | 8015cefc:	bset       r1,r2,r1
      |
      | 8015cf00:	llock      r3,[r4]  <-- atomic op
      | 8015cf04:	brne       r3,r2,8015cf10
      | 8015cf08:	scond      r1,[r4]
      | 8015cf0c:	bnz        8015cf00
      |
      | 8015cf10:	brne       r3,r2,8015cf00  <-- Branch doesn't go to orig LD
      
      Although this was fixed by adding a ACCESS_ONCE in this call site, it
      seems safer (for now at least) to add compiler barrier to LLSC based
      cmpxchg
      Reported-by: NChuck Jordan <cjordan@synopsys,com>
      Cc: <stable@vger.kernel.org>
      Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
      d57f7272
  2. 22 6月, 2015 11 次提交
  3. 19 6月, 2015 11 次提交
  4. 19 5月, 2015 2 次提交
  5. 10 5月, 2015 1 次提交
  6. 20 4月, 2015 2 次提交
  7. 13 4月, 2015 5 次提交
  8. 27 2月, 2015 3 次提交
  9. 13 2月, 2015 2 次提交
    • A
      ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASE · 06f34e1c
      Alexey Brodkin 提交于
      We used to calculate page address differently in 2 cases:
      
      1. In virt_to_page(x) we do
       --->8---
       mem_map + (x - CONFIG_LINUX_LINK_BASE) >> PAGE_SHIFT
       --->8---
      
      2. In in pte_page(x) we do
       --->8---
       mem_map + (pte_val(x) - PAGE_OFFSET) >> PAGE_SHIFT
       --->8---
      
      That leads to problems in case PAGE_OFFSET != CONFIG_LINUX_LINK_BASE -
      different pages will be selected depending on where and how we calculate
      page address.
      
      In particular in the STAR 9000853582 when gdb attempted to read memory
      of another process it got improper page in get_user_pages() because this
      is exactly one of the places where we search for a page by pte_page().
      
      The fix is trivial - we need to calculate page address similarly in both
      cases.
      
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NAlexey Brodkin <abrodkin@synopsys.com>
      Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
      06f34e1c
    • A
      all arches, signal: move restart_block to struct task_struct · f56141e3
      Andy Lutomirski 提交于
      If an attacker can cause a controlled kernel stack overflow, overwriting
      the restart block is a very juicy exploit target.  This is because the
      restart_block is held in the same memory allocation as the kernel stack.
      
      Moving the restart block to struct task_struct prevents this exploit by
      making the restart_block harder to locate.
      
      Note that there are other fields in thread_info that are also easy
      targets, at least on some architectures.
      
      It's also a decent simplification, since the restart code is more or less
      identical on all architectures.
      
      [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
      Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: David Miller <davem@davemloft.net>
      Acked-by: NRichard Weinberger <richard@nod.at>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Guenter Roeck <linux@roeck-us.net>
      Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f56141e3
  10. 12 2月, 2015 1 次提交