linux-toradex.git/arch/s390/kernel/kprobes.c, branch v4.12

s390: use set_memory.h header

2017-05-09T00:15:13+00:00

set_memory_* functions have moved to set_memory.h.  Switch to this
explicitly

Link: http://lkml.kernel.org/r/1488920133-27229-5-git-send-email-labbott@redhat.com
Signed-off-by: Laura Abbott 
Acked-by: Heiko Carstens 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

s390: add no-execute support

2017-02-08T13:13:25+00:00

Bit 0x100 of a page table, segment table of region table entry
can be used to disallow code execution for the virtual addresses
associated with the entry.

There is one tricky bit, the system call to return from a signal
is part of the signal frame written to the user stack. With a
non-executable stack this would stop working. To avoid breaking
things the protection fault handler checks the opcode that caused
the fault for 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn)
and injects a system call. This is preferable to the alternative
solution with a stub function in the vdso because it works for
vdso=off and statically linked binaries as well.

Signed-off-by: Martin Schwidefsky

Replace with globally

2016-12-24T19:46:01+00:00

This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*'
  sed -i -e "s!$PATT!#include !" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro 
Signed-off-by: Linus Torvalds

s390: migrate exception table users off module.h and onto extable.h

2016-09-20T12:26:38+00:00

These files were only including module.h for exception table
related functions.  We've now separated that content out into its
own file "extable.h" so now move over to that and avoid all the
extra header content in module.h that we don't really need to compile
these files.

The additions of uaccess.h are to deal with implict includes like:

arch/s390/kernel/traps.c: In function 'do_report_trap':
arch/s390/kernel/traps.c:56:4: error: implicit declaration of function 'extable_fixup' [-Werror=implicit-function-declaration]
arch/s390/kernel/traps.c: In function 'illegal_op':
arch/s390/kernel/traps.c:173:3: error: implicit declaration of function 'get_user' [-Werror=implicit-function-declaration]

Cc: Heiko Carstens 
Cc: linux-s390@vger.kernel.org
Signed-off-by: Paul Gortmaker 
Signed-off-by: Martin Schwidefsky

s390/ftrace/jprobes: Fix conflict between jprobes and function graph tracing

2016-07-31T13:28:12+00:00

This fixes the same issue Steven already fixed for x86
in following commit:

  237d28db036e ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing

It fixes the crash, that happens when function graph tracing
and jprobes are used simultaneously. Please refer to above
commit for details.

Signed-off-by: Jiri Olsa 
Signed-off-by: Martin Schwidefsky 
Acked-by: Steven Rostedt

s390: remove all usages of PSW_ADDR_INSN

2016-01-19T11:14:03+00:00

Yet another leftover from the 31 bit era. The usual operation
"y = x & PSW_ADDR_INSN" with the PSW_ADDR_INSN mask is a nop for
CONFIG_64BIT.

Therefore remove all usages and hope the code is a bit less confusing.

Signed-off-by: Heiko Carstens 
Reviewed-by: David Hildenbrand

s390: remove all usages of PSW_ADDR_AMODE

2016-01-19T11:14:02+00:00

This is a leftover from the 31 bit area. For CONFIG_64BIT the usual
operation "y = x | PSW_ADDR_AMODE" is a nop. Therefore remove all
usages of PSW_ADDR_AMODE and make the code a bit less confusing.

Signed-off-by: Heiko Carstens 
Reviewed-by: David Hildenbrand

s390/maccess: remove potentially broken probe_kernel_write()

2015-03-25T10:49:43+00:00

Remove the s390 architecture implementation of probe_kernel_write() and
instead use a new function s390_kernel_write() to modify kernel text and
data everywhere.

The s390 implementation of probe_kernel_write() was potentially broken
since it modified memory in a read-modify-write fashion, which read four
bytes, modified the requested bytes within those four bytes and wrote
the result back.
If two cpus would modify the same four byte area at different locations
within that area, this could lead to corruption.
Right now the only places which called probe_kernel_write() did run within
stop_machine_run. Therefore the scenario can't happen right now, however
that might change at any time.

To fix this rename probe_kernel_write() to s390_kernel_write() which can
have special semantics, like only call it while running within stop_machine().

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/ftrace: hotpatch support for function tracing

2015-01-29T08:19:25+00:00

Make use of gcc's hotpatch support to generate better code for ftrace
function tracing.
The generated code now contains only a six byte nop in each function
prologue instead of a 24 byte code block which will be runtime patched to
support function tracing.
With the new code generation the runtime overhead for supporting function
tracing is close to zero, while the original code did show a significant
performance impact.

Acked-by: Steven Rostedt 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/kprobes: fix instruction copy for out of line execution

2014-12-01T10:07:44+00:00

When we generate the instruction for out of line execution the length
of the to be copied instruction was evaluated from a not initialized
memory location.
Therefore we ended up with a random (2, 4 or 6) number of bytes being
copied instead of taking the real instruction length into account.
This works surprisingly well most of the time, but still not always.

Reported-by: Ursula Braun 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky