linux.git/arch/s390/kernel/module.c, branch v4.13

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

module: s390: keep mod_arch_specific for livepatch modules

2016-04-01T13:00:11+00:00

Livepatch needs to utilize the symbol information contained in the
mod_arch_specific struct in order to be able to call the s390
apply_relocate_add() function to apply relocations. Keep a reference to
syminfo if the module is a livepatch module. Remove the redundant vfree()
in module_finalize() since module_arch_freeing_init() (which also frees
those structures) is called in do_init_module(). If the module isn't a
livepatch module, we free the structures in module_arch_freeing_init() as
usual.

Signed-off-by: Jessica Yu 
Reviewed-by: Miroslav Benes 
Acked-by: Josh Poimboeuf 
Acked-by: Heiko Carstens 
Signed-off-by: Jiri Kosina

module: use a structure to encapsulate layout.

2015-12-04T21:46:25+00:00

Makes it easier to handle init vs core cleanly, though the change is
fairly invasive across random architectures.

It simplifies the rbtree code immediately, however, while keeping the
core data together in the same cachline (now iff the rbtree code is
enabled).

Acked-by: Peter Zijlstra 
Reviewed-by: Josh Poimboeuf 
Signed-off-by: Rusty Russell 
Signed-off-by: Jiri Kosina

s390: remove 31 bit support

2015-03-25T10:49:33+00:00

Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.

The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.

Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.

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

s390/jump label: add missing jump_label_apply_nops() call

2015-02-26T08:24:45+00:00

When modules are loaded we want to transform the compile time generated
nops into runtime generated nops. Otherwise the jump label sanity check
will detect invalid code when trying to patch code.

Fixes this crash:

Jump label code mismatch at __rds_conn_create+0x3c/0x720
Found:    c0 04 00 00 00 01
Expected: c0 04 00 00 00 00
Kernel panic - not syncing: Corrupted kernel text
CPU: 0 PID: 10 Comm: migration/0 Not tainted 3.19.0-01935-g006610f #14
Call Trace:
<0000000000113260> show_trace+0xf8/0x158)
<000000000011332a> show_stack+0x6a/0xe8
<000000000069fd64> dump_stack+0x7c/0xd8
<0000000000698d54> panic+0xe4/0x288
<00000000006984c6> jump_label_bug.isra.2+0xbe/0xc001
<000000000011200c> __jump_label_transform+0x94/0xc8

Reported-by: Sebastian Ott 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

mm: vmalloc: pass additional vm_flags to __vmalloc_node_range()

2015-02-14T05:21:42+00:00

For instrumenting global variables KASan will shadow memory backing memory
for modules.  So on module loading we will need to allocate memory for
shadow and map it at address in shadow that corresponds to the address
allocated in module_alloc().

__vmalloc_node_range() could be used for this purpose, except it puts a
guard hole after allocated area.  Guard hole in shadow memory should be a
problem because at some future point we might need to have a shadow memory
at address occupied by guard hole.  So we could fail to allocate shadow
for module_alloc().

Now we have VM_NO_GUARD flag disabling guard page, so we need to pass into
__vmalloc_node_range().  Add new parameter 'vm_flags' to
__vmalloc_node_range() function.

Signed-off-by: Andrey Ryabinin 
Cc: Dmitry Vyukov 
Cc: Konstantin Serebryany 
Cc: Dmitry Chernenkov 
Signed-off-by: Andrey Konovalov 
Cc: Yuri Gribov 
Cc: Konstantin Khlebnikov 
Cc: Sasha Levin 
Cc: Christoph Lameter 
Cc: Joonsoo Kim 
Cc: Dave Hansen 
Cc: Andi Kleen 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Christoph Lameter 
Cc: Pekka Enberg 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

module_arch_freeing_init(): new hook for archs before module->module_init freed.

2015-01-20T01:08:32+00:00

Archs have been abusing module_free() to clean up their arch-specific
allocations.  Since module_free() is also (ab)used by BPF and trace code,
let's keep it to simple allocations, and provide a hook called before
that.

This means that avr32, ia64, parisc and s390 no longer need to implement
their own module_free() at all.  avr32 doesn't need module_finalize()
either.

Signed-off-by: Rusty Russell 
Cc: Chris Metcalf 
Cc: Haavard Skinnemoen 
Cc: Hans-Christian Egtvedt 
Cc: Tony Luck 
Cc: Fenghua Yu 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: linux-kernel@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-s390@vger.kernel.org

mm/arch: use NUMA_NO_NODE

2013-11-13T03:09:05+00:00

Use more appropriate NUMA_NO_NODE instead of -1 in all archs' module_alloc()

Signed-off-by: Jianguo Wu 
Acked-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

s390/module: fix compile warning

2013-02-28T08:37:13+00:00

Get rid of this one (false positive):
arch/s390/kernel/module.c: In function ‘apply_relocate_add’:
arch/s390/kernel/module.c:404:5: warning: ‘rc’ may be used uninitialized
                                 in this function [-Wmaybe-uninitialized]
arch/s390/kernel/module.c:225:6: note: ‘rc’ was declared here

Play safe and preinitialize rc with an error value, so we see an error
if new users indeed don't initialize it.

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

s390/module: Add missing R_390_NONE relocation type

2013-02-14T14:55:26+00:00

Allow loading of kernel modules that have relocations
of type R_390_NONE.

Signed-off-by: Hendrik Brueckner 
Signed-off-by: Martin Schwidefsky