Commit Graph

2276 Commits

Author SHA1 Message Date
Vasily Gorbik 15deb080a6 s390/ipl: ensure loadparm valid flag is set
When loadparm is set in reipl parm block, the kernel should also set
DIAG308_FLAGS_LP_VALID flag.

This fixes loadparm ignoring during z/VM fcp -> ccw reipl and kvm direct
boot -> ccw reipl.

Cc: <stable@vger.kernel.org>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:38:58 +02:00
Heiko Carstens 8b09ca746a s390/compat: fix setup_frame32
Git commit c60a03fee0 ("s390: switch to {get,put}_compat_sigset()")
contains a typo and now copies the wrong pointer to user space.
Use the correct pointer instead.

Reported-and-tested-by: Stefan Liebler <stli@linux.vnet.ibm.com>
Fixes: c60a03fee0 ("s390: switch to {get,put}_compat_sigset()")
Cc: <stable@vger.kernel.org> # v4.15+
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:38:54 +02:00
Linus Torvalds becdce1c66 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:

 - Improvements for the spectre defense:
    * The spectre related code is consolidated to a single file
      nospec-branch.c
    * Automatic enable/disable for the spectre v2 defenses (expoline vs.
      nobp)
    * Syslog messages for specve v2 are added
    * Enable CONFIG_GENERIC_CPU_VULNERABILITIES and define the attribute
      functions for spectre v1 and v2

 - Add helper macros for assembler alternatives and use them to shorten
   the code in entry.S.

 - Add support for persistent configuration data via the SCLP Store Data
   interface. The H/W interface requires a page table that uses 4K pages
   only, the code to setup such an address space is added as well.

 - Enable virtio GPU emulation in QEMU. To do this the depends
   statements for a few common Kconfig options are modified.

 - Add support for format-3 channel path descriptors and add a binary
   sysfs interface to export the associated utility strings.

 - Add a sysfs attribute to control the IFCC handling in case of
   constant channel errors.

 - The vfio-ccw changes from Cornelia.

 - Bug fixes and cleanups.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (40 commits)
  s390/kvm: improve stack frame constants in entry.S
  s390/lpp: use assembler alternatives for the LPP instruction
  s390/entry.S: use assembler alternatives
  s390: add assembler macros for CPU alternatives
  s390: add sysfs attributes for spectre
  s390: report spectre mitigation via syslog
  s390: add automatic detection of the spectre defense
  s390: move nobp parameter functions to nospec-branch.c
  s390/cio: add util_string sysfs attribute
  s390/chsc: query utility strings via fmt3 channel path descriptor
  s390/cio: rename struct channel_path_desc
  s390/cio: fix unbind of io_subchannel_driver
  s390/qdio: split up CCQ handling for EQBS / SQBS
  s390/qdio: don't retry EQBS after CCQ 96
  s390/qdio: restrict buffer merging to eligible devices
  s390/qdio: don't merge ERROR output buffers
  s390/qdio: simplify math in get_*_buffer_frontier()
  s390/decompressor: trim uncompressed image head during the build
  s390/crypto: Fix kernel crash on aes_s390 module remove.
  s390/defkeymap: fix global init to zero
  ...
2018-04-09 09:04:10 -07:00
Randy Dunlap 514c603249 headers: untangle kmemleak.h from mm.h
Currently <linux/slab.h> #includes <linux/kmemleak.h> for no obvious
reason.  It looks like it's only a convenience, so remove kmemleak.h
from slab.h and add <linux/kmemleak.h> to any users of kmemleak_* that
don't already #include it.  Also remove <linux/kmemleak.h> from source
files that do not use it.

This is tested on i386 allmodconfig and x86_64 allmodconfig.  It would
be good to run it through the 0day bot for other $ARCHes.  I have
neither the horsepower nor the storage space for the other $ARCHes.

Update: This patch has been extensively build-tested by both the 0day
bot & kisskb/ozlabs build farms.  Both of them reported 2 build failures
for which patches are included here (in v2).

[ slab.h is the second most used header file after module.h; kernel.h is
  right there with slab.h. There could be some minor error in the
  counting due to some #includes having comments after them and I didn't
  combine all of those. ]

[akpm@linux-foundation.org: security/keys/big_key.c needs vmalloc.h, per sfr]
Link: http://lkml.kernel.org/r/e4309f98-3749-93e1-4bb7-d9501a39d015@infradead.org
Link: http://kisskb.ellerman.id.au/kisskb/head/13396/
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>	[2 build failures]
Reported-by: Fengguang Wu <fengguang.wu@intel.com>	[2 build failures]
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-05 21:36:27 -07:00
Dominik Brodowski c7b95d5156 mm: add ksys_readahead() helper; remove in-kernel calls to sys_readahead()
Using this helper allows us to avoid the in-kernel calls to the
sys_readahead() syscall. The ksys_ prefix denotes that this function is
meant as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_readahead().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:12 +02:00
Dominik Brodowski a90f590a1b mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff()
Using this helper allows us to avoid the in-kernel calls to the
sys_mmap_pgoff() syscall. The ksys_ prefix denotes that this function is
meant as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_mmap_pgoff().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:11 +02:00
Dominik Brodowski 9d5b7c956b mm: add ksys_fadvise64_64() helper; remove in-kernel call to sys_fadvise64_64()
Using the ksys_fadvise64_64() helper allows us to avoid the in-kernel
calls to the sys_fadvise64_64() syscall. The ksys_ prefix denotes that
this function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as ksys_fadvise64_64().

Some compat stubs called sys_fadvise64(), which then just passed through
the arguments to sys_fadvise64_64(). Get rid of this indirection, and call
ksys_fadvise64_64() directly.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:10 +02:00
Dominik Brodowski edf292c76b fs: add ksys_fallocate() wrapper; remove in-kernel calls to sys_fallocate()
Using the ksys_fallocate() wrapper allows us to get rid of in-kernel
calls to the sys_fallocate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_fallocate().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:09 +02:00
Dominik Brodowski 36028d5dd7 fs: add ksys_p{read,write}64() helpers; remove in-kernel calls to syscalls
Using the ksys_p{read,write}64() wrappers allows us to get rid of
in-kernel calls to the sys_pread64() and sys_pwrite64() syscalls.
The ksys_ prefix denotes that this function is meant as a drop-in
replacement for the syscall. In particular, it uses the same calling
convention as sys_p{read,write}64().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:09 +02:00
Dominik Brodowski df260e21e6 fs: add ksys_truncate() wrapper; remove in-kernel calls to sys_truncate()
Using the ksys_truncate() wrapper allows us to get rid of in-kernel
calls to the sys_truncate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_truncate().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:08 +02:00
Dominik Brodowski 806cbae122 fs: add ksys_sync_file_range helper(); remove in-kernel calls to syscall
Using this helper allows us to avoid the in-kernel calls to the
sys_sync_file_range() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it uses
the same calling convention as sys_sync_file_range().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:07 +02:00
Dominik Brodowski 3ce4a7bf66 fs: add ksys_read() helper; remove in-kernel calls to sys_read()
Using this helper allows us to avoid the in-kernel calls to the
sys_read() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it
uses the same calling convention as sys_read().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:04 +02:00
Dominik Brodowski 411d9475cf fs: add ksys_ftruncate() wrapper; remove in-kernel calls to sys_ftruncate()
Using the ksys_ftruncate() wrapper allows us to get rid of in-kernel
calls to the sys_ftruncate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_ftruncate().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:00 +02:00
Dominik Brodowski 55731b3cda fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappers
Using the fs-interal do_fchownat() wrapper allows us to get rid of
fs-internal calls to the sys_fchownat() syscall.

Introducing the ksys_fchown() helper and the ksys_{,}chown() wrappers
allows us to avoid the in-kernel calls to the sys_{,l,f}chown() syscalls.
The ksys_ prefix denotes that these functions are meant as a drop-in
replacement for the syscalls. In particular, they use the same calling
convention as sys_{,l,f}chown().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:59 +02:00
Dominik Brodowski e7a3e8b2ed fs: add ksys_write() helper; remove in-kernel calls to sys_write()
Using this helper allows us to avoid the in-kernel calls to the sys_write()
syscall. The ksys_ prefix denotes that this function is meant as a drop-in
replacement for the syscall. In particular, it uses the same calling
convention as sys_write().

In the near future, the do_mounts / initramfs callers of ksys_write()
should be converted to use filp_open() and vfs_write() instead.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:51 +02:00
Martin Schwidefsky 92fa7a13c8 s390/kvm: improve stack frame constants in entry.S
The code in sie64a uses the stack frame passed to the function to store
some temporary data in the empty1 array (see struct stack_frame in
asm/processor.h.

Replace the __SF_EMPTY+x constants with a properly defined offset:
s/__SF_EMPTY/__SF_SIE_CONTROL/, s/__SF_EMPTY+8/__SF_SIE_SAVEAREA/,
s/__SF_EMPTY+16/__SF_SIE_REASON/, s/__SF_EMPTY+24/__SF_SIE_FLAGS/.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-28 08:38:29 +02:00
Martin Schwidefsky e5b98199de s390/lpp: use assembler alternatives for the LPP instruction
With the new macros for CPU alternatives the MACHINE_FLAG_LPP check
around the LPP instruction can be optimized. After this is done the
flag can be removed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-28 08:38:28 +02:00
Martin Schwidefsky b058661a99 s390/entry.S: use assembler alternatives
Replace the open coded alternatives for the BPOFF, BPON, BPENTER,
and BPEXIT macros with the new magic from asm/alternatives-asm.h
to make the code easier to read.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-28 08:38:28 +02:00
Martin Schwidefsky d424986f1d s390: add sysfs attributes for spectre
Set CONFIG_GENERIC_CPU_VULNERABILITIES and provide the two functions
cpu_show_spectre_v1 and cpu_show_spectre_v2 to report the spectre
mitigations.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-28 08:38:26 +02:00
Martin Schwidefsky bc03559971 s390: report spectre mitigation via syslog
Add a boot message if either of the spectre defenses is active.
The message is
    "Spectre V2 mitigation: execute trampolines."
or  "Spectre V2 mitigation: limited branch prediction."

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-28 08:38:25 +02:00
Martin Schwidefsky 6e179d6412 s390: add automatic detection of the spectre defense
Automatically decide between nobp vs. expolines if the spectre_v2=auto
kernel parameter is specified or CONFIG_EXPOLINE_AUTO=y is set.

The decision made at boot time due to CONFIG_EXPOLINE_AUTO=y being set
can be overruled with the nobp, nospec and spectre_v2 kernel parameters.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-28 08:38:24 +02:00
Martin Schwidefsky b2e2f43a01 s390: move nobp parameter functions to nospec-branch.c
Keep the code for the nobp parameter handling with the code for
expolines. Both are related to the spectre v2 mitigation.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-28 08:38:23 +02:00
Farhan Ali 579f1a2883 s390/setup : enable display support for KVM guest
The S390 architecture does not support any graphics hardware,
but with the latest support for Virtio GPU in Linux and Virtio
GPU emulation in QEMU, it's possible to enable graphics for
S390 using the Virtio GPU device.

To enable display we need to enable the Linux Virtual Terminal (VT)
layer for S390. But the VT subsystem initializes quite early
at boot so we need a dummy console driver till the Virtio GPU
driver is initialized and we can run the framebuffer console.

The framebuffer console over a Virtio GPU device can be run
in combination with the serial SCLP console (default on S390).
The SCLP console can still be accessed by management applications
(eg: via Libvirt's virsh console).

Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <e23b61f4f599ba23881727a1e8880e9d60cc6a48.1519315352.git.alifm@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-18 23:01:58 -07:00
Christian Borntraeger d3f468963c s390/entry.S: fix spurious zeroing of r0
when a system call is interrupted we might call the critical section
cleanup handler that re-does some of the operations. When we are between
.Lsysc_vtime and .Lsysc_do_svc we might also redo the saving of the
problem state registers r0-r7:

.Lcleanup_system_call:
[...]
0:      # update accounting time stamp
        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
        # set up saved register r11
        lg      %r15,__LC_KERNEL_STACK
        la      %r9,STACK_FRAME_OVERHEAD(%r15)
        stg     %r9,24(%r11)            # r11 pt_regs pointer
        # fill pt_regs
        mvc     __PT_R8(64,%r9),__LC_SAVE_AREA_SYNC
--->    stmg    %r0,%r7,__PT_R0(%r9)

The problem is now, that we might have already zeroed out r0.
The fix is to move the zeroing of r0 after sysc_do_svc.

Reported-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Fixes: 7041d28115 ("s390: scrub registers on kernel entry and KVM exit")
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-06 09:19:35 +01:00
Vasily Gorbik 320d9555cb s390: unify linker symbols usage
Common code defines linker symbols which denote sections start/end in
a form of char []. Referencing those symbols as _symbol or &_symbol
yields the same result, but "_symbol" form is more widespread across
newly written code. Convert s390 specific code to this style.

Also removes unused _text symbol definition in boot/compressed/misc.c.

Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-27 08:05:23 +01:00
Martin Schwidefsky d5feec04fe s390: do not bypass BPENTER for interrupt system calls
The system call path can be interrupted before the switch back to the
standard branch prediction with BPENTER has been done. The critical
section cleanup code skips forward to .Lsysc_do_svc and bypasses the
BPENTER. In this case the kernel and all subsequent code will run with
the limited branch prediction.

Fixes: eacf67eb9b32 ("s390: run user space and KVM guests with modified branch prediction")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-22 14:08:51 +01:00
Hendrik Brueckner dc24b7b49a s390/clean-up: use CFI_* macros in entry.S
Commit f19fbd5ed6 ("s390: introduce execute-trampolines for
branches") introduces .cfi_* assembler directives.  Instead of
using the directives directly, use the macros from asm/dwarf.h.
This also ensures that the dwarf debug information are created
in the .debug_frame section.

Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-22 10:09:20 +01:00
Eugeniu Rosca 2cb370d615 s390: Replace IS_ENABLED(EXPOLINE_*) with IS_ENABLED(CONFIG_EXPOLINE_*)
I've accidentally stumbled upon the IS_ENABLED(EXPOLINE_*) lines, which
obviously always evaluate to false. Fix this.

Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-19 08:00:06 +01:00
Martin Schwidefsky f19fbd5ed6 s390: introduce execute-trampolines for branches
Add CONFIG_EXPOLINE to enable the use of the new -mindirect-branch= and
-mfunction_return= compiler options to create a kernel fortified against
the specte v2 attack.

With CONFIG_EXPOLINE=y all indirect branches will be issued with an
execute type instruction. For z10 or newer the EXRL instruction will
be used, for older machines the EX instruction. The typical indirect
call

	basr	%r14,%r1

is replaced with a PC relative call to a new thunk

	brasl	%r14,__s390x_indirect_jump_r1

The thunk contains the EXRL/EX instruction to the indirect branch

__s390x_indirect_jump_r1:
	exrl	0,0f
	j	.
0:	br	%r1

The detour via the execute type instruction has a performance impact.
To get rid of the detour the new kernel parameter "nospectre_v2" and
"spectre_v2=[on,off,auto]" can be used. If the parameter is specified
the kernel and module code will be patched at runtime.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-07 15:57:02 +01:00
Martin Schwidefsky 6b73044b2b s390: run user space and KVM guests with modified branch prediction
Define TIF_ISOLATE_BP and TIF_ISOLATE_BP_GUEST and add the necessary
plumbing in entry.S to be able to run user space and KVM guests with
limited branch prediction.

To switch a user space process to limited branch prediction the
s390_isolate_bp() function has to be call, and to run a vCPU of a KVM
guest associated with the current task with limited branch prediction
call s390_isolate_bp_guest().

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-05 14:48:50 +01:00
Martin Schwidefsky d768bd892f s390: add options to change branch prediction behaviour for the kernel
Add the PPA instruction to the system entry and exit path to switch
the kernel to a different branch prediction behaviour. The instructions
are added via CPU alternatives and can be disabled with the "nospec"
or the "nobp=0" kernel parameter. If the default behaviour selected
with CONFIG_KERNEL_NOBP is set to "n" then the "nobp=1" parameter can be
used to enable the changed kernel branch prediction.

Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-05 13:49:17 +01:00
Martin Schwidefsky cf14899846 s390/alternative: use a copy of the facility bit mask
To be able to switch off specific CPU alternatives with kernel parameters
make a copy of the facility bit mask provided by STFLE and use the copy
for the decision to apply an alternative.

Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-05 13:49:16 +01:00
Martin Schwidefsky 7041d28115 s390: scrub registers on kernel entry and KVM exit
Clear all user space registers on entry to the kernel and all KVM guest
registers on KVM guest exit if the register does not contain either a
parameter or a result value.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-05 07:34:54 +01:00
Heiko Carstens 6587553031 s390/runtime_instrumentation: re-add signum system call parameter
Add the signum system call parameter for documentation purposes only,
and without checking if the passed value is a valid real-time signal.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-05 07:34:50 +01:00
Hendrik Brueckner 81507f38d4 s390/cpum_cf: correct counter number of LAST_HOST_TRANSLATIONS
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-02 10:47:16 +01:00
Masami Hiramatsu 0e1647b390 s390/kprobes: Fix %p uses in error messages
Remove %p because the kprobe will be dumped in dump_kprobe().

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-02 10:47:15 +01:00
Hendrik Brueckner 5260b0f50c s390/sysinfo: add and display licensed internal code identifier
With z14, the store system information instruction provides an
licensed internal code identifier.  Display it in /proc/sysinfo.

For more information, see the z/Architecture Principles of Operation.
(SA22-7832-11).

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-02 10:47:15 +01:00
Linus Torvalds 47fcc0360c Driver Core updates for 4.16-rc1
Here is the set of "big" driver core patches for 4.16-rc1.
 
 The majority of the work here is in the firmware subsystem, with reworks
 to try to attempt to make the code easier to handle in the long run, but
 no functional change.  There's also some tree-wide sysfs attribute
 fixups with lots of acks from the various subsystem maintainers, as well
 as a handful of other normal fixes and changes.
 
 And finally, some license cleanups for the driver core and sysfs code.
 
 All have been in linux-next for a while with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the set of "big" driver core patches for 4.16-rc1.

  The majority of the work here is in the firmware subsystem, with
  reworks to try to attempt to make the code easier to handle in the
  long run, but no functional change. There's also some tree-wide sysfs
  attribute fixups with lots of acks from the various subsystem
  maintainers, as well as a handful of other normal fixes and changes.

  And finally, some license cleanups for the driver core and sysfs code.

  All have been in linux-next for a while with no reported issues"

* tag 'driver-core-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (48 commits)
  device property: Define type of PROPERTY_ENRTY_*() macros
  device property: Reuse property_entry_free_data()
  device property: Move property_entry_free_data() upper
  firmware: Fix up docs referring to FIRMWARE_IN_KERNEL
  firmware: Drop FIRMWARE_IN_KERNEL Kconfig option
  USB: serial: keyspan: Drop firmware Kconfig options
  sysfs: remove DEBUG defines
  sysfs: use SPDX identifiers
  drivers: base: add coredump driver ops
  sysfs: add attribute specification for /sysfs/devices/.../coredump
  test_firmware: fix missing unlock on error in config_num_requests_store()
  test_firmware: make local symbol test_fw_config static
  sysfs: turn WARN() into pr_warn()
  firmware: Fix a typo in fallback-mechanisms.rst
  treewide: Use DEVICE_ATTR_WO
  treewide: Use DEVICE_ATTR_RO
  treewide: Use DEVICE_ATTR_RW
  sysfs.h: Use octal permissions
  component: add debugfs support
  bus: simple-pm-bus: convert bool SIMPLE_PM_BUS to tristate
  ...
2018-02-01 10:00:28 -08:00
Linus Torvalds ca0c836d88 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:
 "Bug fixes, small improvements and one notable change: the system call
  table and the unistd.h header are now generated automatically with a
  shell script from a text file"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/decompressor: discard __ksymtab and .eh_frame sections
  s390: fix handling of -1 in set{,fs}[gu]id16 syscalls
  s390/tools: generate header files in arch/s390/include/generated/
  s390/syscalls: use generated syscall_table.h and unistd.h header files
  s390/syscalls: add Makefile to generate system call header files
  s390/syscalls: add syscalltbl script
  s390/syscalls: add system call table
  s390/decompressor: swap .text and .rodata.compressed sections
  s390/sclp: fix .data section specification
  s390/ipl: avoid usage of __section(.data)
  s390/head: replace hard coded values with constants
  s390/disassembler: add generated gen_opcode_table tool to .gitignore
  s390: remove bogus system call table entries
  s390/kprobes: remove duplicate includes
  s390/dasd: Remove dead return code checks
  s390/dasd: Simplify code
  s390/vdso: revise CFI annotations of vDSO functions
  s390/kernel: emit CFI data in .debug_frame and discard .eh_frame sections
2018-02-01 09:31:04 -08:00
Eugene Syromiatnikov 6dd0d2d22a s390: fix handling of -1 in set{,fs}[gu]id16 syscalls
For some reason, the implementation of some 16-bit ID system calls
(namely, setuid16/setgid16 and setfsuid16/setfsgid16) used type cast
instead of low2highgid/low2highuid macros for converting [GU]IDs, which
led to incorrect handling of value of -1 (which ought to be considered
invalid).

Discovered by strace test suite.

Cc: stable@vger.kernel.org
Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-01-23 07:36:54 +01:00
Hendrik Brueckner 4381f9f12e s390/syscalls: use generated syscall_table.h and unistd.h header files
Update the uapi/asm/unistd.h to include the generated compat and
64-bit version of the unistd.h and, as well as, the unistd_nr.h
header file.  Also remove the arch/s390/kernel/syscalls.S file
and use the generated system call table, syscall_table.h, instead.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-01-23 07:36:52 +01:00
Hendrik Brueckner 5c75824d91 s390/syscalls: add Makefile to generate system call header files
Generate the system call specific files from the archheaders
and archprepare make targets.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-01-23 07:36:51 +01:00
Hendrik Brueckner fd834e0970 s390/syscalls: add syscalltbl script
Introduce the syscalltbl script to read the system call table and
generate respective uapi unistd.h header files.  Also it generates
the contents syscalls.S - the real system call table - which is
included by arch/s390/kernel/entry.S.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-01-23 07:36:51 +01:00
Hendrik Brueckner 857f46bfb0 s390/syscalls: add system call table
Add a table that lists available system calls and their entry
functions.  With this change, adding new system calls become
fairly easy:

  1. Add a new table entry consisting of the system call number,
     abi (common or 64/31 bit only), and the entry functions.
  2. If necessary, create a compat syscall wrapper.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-01-23 07:36:50 +01:00
Vasily Gorbik c50ce358bd s390/ipl: avoid usage of __section(.data)
bss section is cleared before ipl.c code is called or global variables
are used nowadays. Remove stale comment and __section(.data) from
few global variables.

Also removes static/global variables initialization to 0.

Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-01-23 07:36:47 +01:00
Vasily Gorbik 34ba2450ab s390/head: replace hard coded values with constants
A couple of the low core offsets are repeatedly used throughout head.S
and are hard coded. Replace them with corresponding constants from
asm-offsets.h to improve readability.

Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-01-23 07:36:46 +01:00
Heiko Carstens 9797f14404 s390: remove bogus system call table entries
The 64 bit system call table contains three entries that come without
a matching NR_<name> entry in unistd.h.  In fact all three of them do
not make sense on 64 bit, but only for compat processes.

llseek and mmap2 were specifically introduced for 32 bit / compat
processes. getrlimit is wired up twice, so that only the entry that
comes with a corresponding NR_getrlimit needs to be kept.

The other entries can be removed, since it seems very unlikely that
this will break user space.

Reported-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-01-23 07:36:45 +01:00
Pravin Shedge 0a12ed2c21 s390/kprobes: remove duplicate includes
These duplicate includes have been found with scripts/checkincludes.pl but
they have been removed manually to avoid removing false positives.

Signed-off-by: Pravin Shedge <pravin.shedge4linux@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-01-23 07:36:44 +01:00
Eric W. Biederman ea64d5acc8 signal: Unify and correct copy_siginfo_to_user32
Among the existing architecture specific versions of
copy_siginfo_to_user32 there are several different implementation
problems.  Some architectures fail to handle all of the cases in in
the siginfo union.  Some architectures perform a blind copy of the
siginfo union when the si_code is negative.  A blind copy suggests the
data is expected to be in 32bit siginfo format, which means that
receiving such a signal via signalfd won't work, or that the data is
in 64bit siginfo and the code is copying nonsense to userspace.

Create a single instance of copy_siginfo_to_user32 that all of the
architectures can share, and teach it to handle all of the cases in
the siginfo union correctly, with the assumption that siginfo is
stored internally to the kernel is 64bit siginfo format.

A special case is made for x86 x32 format.  This is needed as presence
of both x32 and ia32 on x86_64 results in two different 32bit signal
formats.  By allowing this small special case there winds up being
exactly one code base that needs to be maintained between all of the
architectures.  Vastly increasing the testing base and the chances of
finding bugs.

As the x86 copy of copy_siginfo_to_user32 the call of the x86
signal_compat_build_tests were moved into sigaction_compat_abi, so
that they will keep running.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-01-15 19:56:20 -06:00
Eric W. Biederman 212a36a17e signal: Unify and correct copy_siginfo_from_user32
The function copy_siginfo_from_user32 is used for two things, in ptrace
since the dawn of siginfo for arbirarily modifying a signal that
user space sees, and in sigqueueinfo to send a signal with arbirary
siginfo data.

Create a single copy of copy_siginfo_from_user32 that all architectures
share, and teach it to handle all of the cases in the siginfo union.

In the generic version of copy_siginfo_from_user32 ensure that all
of the fields in siginfo are initialized so that the siginfo structure
can be safely copied to userspace if necessary.

When copying the embedded sigval union copy the si_int member.  That
ensures the 32bit values passes through the kernel unchanged.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-01-15 17:55:59 -06:00