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  1. Feb 04, 2015
  3. Jan 27, 2015
  5. Jan 23, 2015
  7. Jan 20, 2015
  9. Jan 17, 2015
  11. Jan 16, 2015
  13. Jan 15, 2015
    • Steven Rostedt (Red Hat)'s avatar
      ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing · 237d28db
      Steven Rostedt (Red Hat) authored 
      If the function graph tracer traces a jprobe callback, the system will
crash. This can easily be demonstrated by compiling the jprobe
sample module that is in the kernel tree, loading it and running the
function graph tracer.

 # modprobe jprobe_example.ko
 # echo function_graph > /sys/kernel/debug/tracing/current_tracer
 # ls

The first two commands end up in a nice crash after the first fork.
(do_fork has a jprobe attached to it, so "ls" just triggers that fork)

The problem is caused by the jprobe_return() that all jprobe callbacks
must end with. The way jprobes works is that the function a jprobe
is attached to has a breakpoint placed at the start of it (or it uses
ftrace if fentry is supported). The breakpoint handler (or ftrace callback)
will copy the stack frame and change the ip address to return to the
jprobe handler instead of the function. The jprobe handler must end
with jprobe_return() which swaps the stack and does an int3 (breakpoint).
This breakpoint handler will then put back the saved stack frame,
simulate the instruction at the beginning of the function it added
a breakpoint to, and then continue on.

For function tracing to work, it hijakes the return address from the
stack frame, and replaces it with a hook function that will trace
the end of the call. This hook function will restore the return
address of the function call.

If the function tracer traces the jprobe handler, the hook function
for that handler will not be called, and its saved return address
will be used for the next function. This will result in a kernel crash.

To solve this, pause function tracing before the jprobe handler is called
and unpause it before it returns back to the function it probed.

Some other updates:

Used a variable "saved_sp" to hold kcb->jprobe_saved_sp. This makes the
code look a bit cleaner and easier to understand (various tries to fix
this bug required this change).

Note, if fentry is being used, jprobes will change the ip address before
the function graph tracer runs and it will not be able to trace the
function that the jprobe is probing.

Link: http://lkml.kernel.org/r/20150114154329.552437962@goodmis.org



Cc: stable@vger.kernel.org # 2.6.30+
Acked-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      237d28db
  15. Jan 13, 2015
    • Mathias Krause's avatar
      crypto: add missing crypto module aliases · 3e14dcf7
      Mathias Krause authored 
      Commit 5d26a105 ("crypto: prefix module autoloading with "crypto-"")
changed the automatic module loading when requesting crypto algorithms
to prefix all module requests with "crypto-". This requires all crypto
modules to have a crypto specific module alias even if their file name
would otherwise match the requested crypto algorithm.

Even though commit 5d26a105 added those aliases for a vast amount of
modules, it was missing a few. Add the required MODULE_ALIAS_CRYPTO
annotations to those files to make them get loaded automatically, again.
This fixes, e.g., requesting 'ecb(blowfish-generic)', which used to work
with kernels v3.18 and below.

Also change MODULE_ALIAS() lines to MODULE_ALIAS_CRYPTO(). The former
won't work for crypto modules any more.

Fixes: 5d26a105

 ("crypto: prefix module autoloading with "crypto-"")
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: default avatarMathias Krause <minipli@googlemail.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      3e14dcf7
    • Jan Beulich's avatar
      x86/xen: properly retrieve NMI reason · f221b04f
      Jan Beulich authored 
      

Using the native code here can't work properly, as the hypervisor would
normally have cleared the two reason bits by the time Dom0 gets to see
the NMI (if passed to it at all). There's a shared info field for this,
and there's an existing hook to use - just fit the two together. This
is particularly relevant so that NMIs intended to be handled by APEI /
GHES actually make it to the respective handler.

Note that the hook can (and should) be used irrespective of whether
being in Dom0, as accessing port 0x61 in a DomU would be even worse,
while the shared info field would just hold zero all the time. Note
further that hardware NMI handling for PVH doesn't currently work
anyway due to missing code in the hypervisor (but it is expected to
work the native rather than the PV way).

Signed-off-by: default avatarJan Beulich <jbeulich@suse.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      f221b04f
  17. Jan 12, 2015
  19. Jan 09, 2015
  21. Jan 08, 2015
  23. Jan 06, 2015
  25. Jan 05, 2015
    • Vinson Lee's avatar
      crypto: sha-mb - Add avx2_supported check. · 0b8c960c
      Vinson Lee authored 
      

This patch fixes this allyesconfig target build error with older
binutils.

  LD      arch/x86/crypto/built-in.o
ld: arch/x86/crypto/sha-mb/built-in.o: No such file: No such file or directory

Cc: stable@vger.kernel.org # 3.18+
Signed-off-by: default avatarVinson Lee <vlee@twitter.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      0b8c960c
    • Mathias Krause's avatar
      crypto: aesni - fix "by8" variant for 128 bit keys · 0b1e95b2
      Mathias Krause authored 
      

The "by8" counter mode optimization is broken for 128 bit keys with
input data longer than 128 bytes. It uses the wrong key material for
en- and decryption.

The key registers xkey0, xkey4, xkey8 and xkey12 need to be preserved
in case we're handling more than 128 bytes of input data -- they won't
get reloaded after the initial load. They must therefore be (a) loaded
on the first iteration and (b) be preserved for the latter ones. The
implementation for 128 bit keys does not comply with (a) nor (b).

Fix this by bringing the implementation back to its original source
and correctly load the key registers and preserve their values by
*not* re-using the registers for other purposes.

Kudos to James for reporting the issue and providing a test case
showing the discrepancies.

Reported-by: default avatarJames Yonan <james@openvpn.net>
Cc: Chandramouli Narayanan <mouli@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.18
Signed-off-by: default avatarMathias Krause <minipli@googlemail.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      0b1e95b2
  27. Jan 04, 2015
    • Daniel Borkmann's avatar
      x86, um: actually mark system call tables readonly · b485342b
      Daniel Borkmann authored 
      Commit a074335a ("x86, um: Mark system call tables readonly") was
supposed to mark the sys_call_table in UML as RO by adding the const,
but it doesn't have the desired effect as it's nevertheless being placed
into the data section since __cacheline_aligned enforces sys_call_table
being placed into .data..cacheline_aligned instead. We need to use
the ____cacheline_aligned version instead to fix this issue.

Before:

$ nm -v arch/x86/um/sys_call_table_64.o | grep -1 "sys_call_table"
                 U sys_writev
0000000000000000 D sys_call_table
0000000000000000 D syscall_table_size

After:

$ nm -v arch/x86/um/sys_call_table_64.o | grep -1 "sys_call_table"
                 U sys_writev
0000000000000000 R sys_call_table
0000000000000000 D syscall_table_size

Fixes: a074335a

 ("x86, um: Mark system call tables readonly")
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
      b485342b