2193 Commits

Author SHA1 Message Date
Martin Schwidefsky
b3aef39ba1 s390/setup: fix boot crash for machine without EDAT-1
commit 86a86804e4f18fc3880541b3d5a07f4df0fe29cb upstream.

The fix to make WARN work in the early boot code created a problem
on older machines without EDAT-1. The setup_lowcore_dat_on function
uses the pointer from lowcore_ptr[0] to set the DAT bit in the new
PSWs. That does not work if the kernel page table is set up with
4K pages as the prefix address maps to absolute zero.

To make this work the PSWs need to be changed with via address 0 in
form of the S390_lowcore definition.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Cornelia Huck <cohuck@redhat.com>
Fixes: 94f85ed3e2f8 ("s390/setup: fix early warning messages")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23 14:35:32 +01:00
Martin Schwidefsky
6f87f87925 s390/setup: fix early warning messages
commit 8727638426b0aea59d7f904ad8ddf483f9234f88 upstream.

The setup_lowcore() function creates a new prefix page for the boot CPU.
The PSW mask for the system_call, external interrupt, i/o interrupt and
the program check handler have the DAT bit set in this new prefix page.

At the time setup_lowcore is called the system still runs without virtual
address translation, the paging_init() function creates the kernel page
table and loads the CR13 with the kernel ASCE.

Any code between setup_lowcore() and the end of paging_init() that has
a BUG or WARN statement will create a program check that can not be
handled correctly as there is no kernel page table yet.

To allow early WARN statements initially setup the lowcore with DAT off
and set the DAT bit only after paging_init() has completed.

Cc: stable@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23 14:35:20 +01:00
David Hildenbrand
531ebf894c s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU
commit 60f1bf29c0b2519989927cae640cd1f50f59dc7f upstream.

When calling smp_call_ipl_cpu() from the IPL CPU, we will try to read
from pcpu_devices->lowcore. However, due to prefixing, that will result
in reading from absolute address 0 on that CPU. We have to go via the
actual lowcore instead.

This means that right now, we will read lc->nodat_stack == 0 and
therfore work on a very wrong stack.

This BUG essentially broke rebooting under QEMU TCG (which will report
a low address protection exception). And checking under KVM, it is
also broken under KVM. With 1 VCPU it can be easily triggered.

:/# echo 1 > /proc/sys/kernel/sysrq
:/# echo b > /proc/sysrq-trigger
[   28.476745] sysrq: SysRq : Resetting
[   28.476793] Kernel stack overflow.
[   28.476817] CPU: 0 PID: 424 Comm: sh Not tainted 5.0.0-rc1+ #13
[   28.476820] Hardware name: IBM 2964 NE1 716 (KVM/Linux)
[   28.476826] Krnl PSW : 0400c00180000000 0000000000115c0c (pcpu_delegate+0x12c/0x140)
[   28.476861]            R:0 T:1 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
[   28.476863] Krnl GPRS: ffffffffffffffff 0000000000000000 000000000010dff8 0000000000000000
[   28.476864]            0000000000000000 0000000000000000 0000000000ab7090 000003e0006efbf0
[   28.476864]            000000000010dff8 0000000000000000 0000000000000000 0000000000000000
[   28.476865]            000000007fffc000 0000000000730408 000003e0006efc58 0000000000000000
[   28.476887] Krnl Code: 0000000000115bfe: 4170f000            la      %r7,0(%r15)
[   28.476887]            0000000000115c02: 41f0a000            la      %r15,0(%r10)
[   28.476887]           #0000000000115c06: e370f0980024        stg     %r7,152(%r15)
[   28.476887]           >0000000000115c0c: c0e5fffff86e        brasl   %r14,114ce8
[   28.476887]            0000000000115c12: 41f07000            la      %r15,0(%r7)
[   28.476887]            0000000000115c16: a7f4ffa8            brc     15,115b66
[   28.476887]            0000000000115c1a: 0707                bcr     0,%r7
[   28.476887]            0000000000115c1c: 0707                bcr     0,%r7
[   28.476901] Call Trace:
[   28.476902] Last Breaking-Event-Address:
[   28.476920]  [<0000000000a01c4a>] arch_call_rest_init+0x22/0x80
[   28.476927] Kernel panic - not syncing: Corrupt kernel stack, can't continue.
[   28.476930] CPU: 0 PID: 424 Comm: sh Not tainted 5.0.0-rc1+ #13
[   28.476932] Hardware name: IBM 2964 NE1 716 (KVM/Linux)
[   28.476932] Call Trace:

Fixes: 2f859d0dad81 ("s390/smp: reduce size of struct pcpu")
Cc: stable@vger.kernel.org # 4.0+
Reported-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-31 08:13:47 +01:00
Gerald Schaefer
826ea4c108 s390/smp: fix CPU hotplug deadlock with CPU rescan
commit b7cb707c373094ce4008d4a6ac9b6b366ec52da5 upstream.

smp_rescan_cpus() is called without the device_hotplug_lock, which can lead
to a dedlock when a new CPU is found and immediately set online by a udev
rule.

This was observed on an older kernel version, where the cpu_hotplug_begin()
loop was still present, and it resulted in hanging chcpu and systemd-udev
processes. This specific deadlock will not show on current kernels. However,
there may be other possible deadlocks, and since smp_rescan_cpus() can still
trigger a CPU hotplug operation, the device_hotplug_lock should be held.

For reference, this was the deadlock with the old cpu_hotplug_begin() loop:

        chcpu (rescan)                       systemd-udevd

 echo 1 > /sys/../rescan
 -> smp_rescan_cpus()
 -> (*) get_online_cpus()
    (increases refcount)
 -> smp_add_present_cpu()
    (new CPU found)
 -> register_cpu()
 -> device_add()
 -> udev "add" event triggered -----------> udev rule sets CPU online
                                         -> echo 1 > /sys/.../online
                                         -> lock_device_hotplug_sysfs()
                                            (this is missing in rescan path)
                                         -> device_online()
                                         -> (**) device_lock(new CPU dev)
                                         -> cpu_up()
                                         -> cpu_hotplug_begin()
                                            (loops until refcount == 0)
                                            -> deadlock with (*)
 -> bus_probe_device()
 -> device_attach()
 -> device_lock(new CPU dev)
    -> deadlock with (**)

Fix this by taking the device_hotplug_lock in the CPU rescan path.

Cc: <stable@vger.kernel.org>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-31 08:13:43 +01:00
Christian Borntraeger
bd9759a4a4 s390/early: improve machine detection
commit 03aa047ef2db4985e444af6ee1c1dd084ad9fb4c upstream.

Right now the early machine detection code check stsi 3.2.2 for "KVM"
and set MACHINE_IS_VM if this is different. As the console detection
uses diagnose 8 if MACHINE_IS_VM returns true this will crash Linux
early for any non z/VM system that sets a different value than KVM.
So instead of assuming z/VM, do not set any of MACHINE_IS_LPAR,
MACHINE_IS_VM, or MACHINE_IS_KVM.

CC: stable@vger.kernel.org
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-31 08:13:43 +01:00
Thomas Richter
250dea0dfb s390/cpum_cf: Reject request for sampling in event initialization
[ Upstream commit 613a41b0d16e617f46776a93b975a1eeea96417c ]

On s390 command perf top fails
[root@s35lp76 perf] # ./perf top -F100000  --stdio
   Error:
   cycles: PMU Hardware doesn't support sampling/overflow-interrupts.
   	Try 'perf stat'
[root@s35lp76 perf] #

Using event -e rb0000 works as designed.  Event rb0000 is the event
number of the sampling facility for basic sampling.

During system start up the following PMUs are installed in the kernel's
PMU list (from head to tail):
   cpum_cf --> s390 PMU counter facility device driver
   cpum_sf --> s390 PMU sampling facility device driver
   uprobe
   kprobe
   tracepoint
   task_clock
   cpu_clock

Perf top executes following functions and calls perf_event_open(2) system
call with different parameters many times:

cmd_top
--> __cmd_top
    --> perf_evlist__add_default
        --> __perf_evlist__add_default
            --> perf_evlist__new_cycles (creates event type:0 (HW)
			    		config 0 (CPU_CYCLES)
	        --> perf_event_attr__set_max_precise_ip
		    Uses perf_event_open(2) to detect correct
		    precise_ip level. Fails 3 times on s390 which is ok.

Then functions cmd_top
--> __cmd_top
    --> perf_top__start_counters
        -->perf_evlist__config
	   --> perf_can_comm_exec
               --> perf_probe_api
	           This functions test support for the following events:
		   "cycles:u", "instructions:u", "cpu-clock:u" using
		   --> perf_do_probe_api
		       --> perf_event_open_cloexec
		           Test the close on exec flag support with
			   perf_event_open(2).
	               perf_do_probe_api returns true if the event is
		       supported.
		       The function returns true because event cpu-clock is
		       supported by the PMU cpu_clock.
	               This is achieved by many calls to perf_event_open(2).

Function perf_top__start_counters now calls perf_evsel__open() for every
event, which is the default event cpu_cycles (config:0) and type HARDWARE
(type:0) which a predfined frequence of 4000.

Given the above order of the PMU list, the PMU cpum_cf gets called first
and returns 0, which indicates support for this sampling. The event is
fully allocated in the function perf_event_open (file kernel/event/core.c
near line 10521 and the following check fails:

        event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
		                 NULL, NULL, cgroup_fd);
	if (IS_ERR(event)) {
		err = PTR_ERR(event);
		goto err_cred;
	}

        if (is_sampling_event(event)) {
		if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
			err = -EOPNOTSUPP;
			goto err_alloc;
		}
	}

The check for the interrupt capabilities fails and the system call
perf_event_open() returns -EOPNOTSUPP (-95).

Add a check to return -ENODEV when sampling is requested in PMU cpum_cf.
This allows common kernel code in the perf_event_open() system call to
test the next PMU in above list.

Fixes: 97b1198fece0 (" "s390, perf: Use common PMU interrupt disabled code")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-17 09:28:48 +01:00
Thomas Richter
850e4ca786 s390/perf: Change CPUM_CF return code in event init function
[ Upstream commit 0bb2ae1b26e1fb7543ec7474cdd374ac4b88c4da ]

The function perf_init_event() creates a new event and
assignes it to a PMU. This a done in a loop over all existing
PMUs. For each listed PMU the event init function is called
and if this function does return any other error than -ENOENT,
the loop is terminated the creation of the event fails.

If the event is invalid, return -ENOENT to try other PMUs.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-27 16:10:49 +01:00
Vasily Gorbik
221609ce4c s390/vdso: add missing FORCE to build targets
[ Upstream commit b44b136a3773d8a9c7853f8df716bd1483613cbb ]

According to Documentation/kbuild/makefiles.txt all build targets using
if_changed should use FORCE as well. Add missing FORCE to make sure
vdso targets are rebuild properly when not just immediate prerequisites
have changed but also when build command differs.

Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-27 16:10:47 +01:00
Heiko Carstens
9374ffc6f3 s390/sysinfo: add missing #ifdef CONFIG_PROC_FS
[ Upstream commit 9f35b818a2f90fb6cb291aa0c9f835d4f0974a9a ]

Get rid of this compile warning for !PROC_FS:

  CC      arch/s390/kernel/sysinfo.o
arch/s390/kernel/sysinfo.c:275:12: warning: 'sysinfo_show' defined but not used [-Wunused-function]
 static int sysinfo_show(struct seq_file *m, void *v)

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-03 17:00:49 -07:00
Philipp Rudo
a2805f40c7 s390/kdump: Fix memleak in nt_vmcoreinfo
[ Upstream commit 2d2e7075b87181ed0c675e4936e20bdadba02e1f ]

The vmcoreinfo of a crashed system is potentially fragmented. Thus the
crash kernel has an intermediate step where the vmcoreinfo is copied into a
temporary, continuous buffer in the crash kernel memory. This temporary
buffer is never freed. Free it now to prevent the memleak.

While at it replace all occurrences of "VMCOREINFO" by its corresponding
macro to prevent potential renaming issues.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15 09:45:28 +02:00
Christian Borntraeger
2b6eff5923 s390: Correct register corruption in critical section cleanup
commit 891f6a726cacbb87e5b06076693ffab53bd378d7 upstream.

In the critical section cleanup we must not mess with r1.  For march=z9
or older, larl + ex (instead of exrl) are used with r1 as a temporary
register. This can clobber r1 in several interrupt handlers. Fix this by
using r11 as a temp register.  r11 is being saved by all callers of
cleanup_critical.

Fixes: 6dd85fbb87 ("s390: move expoline assembler macros to a header")
Cc: stable@vger.kernel.org #v4.16
Reported-by: Oliver Kurz <okurz@suse.com>
Reported-by: Petr Tesařík <ptesarik@suse.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-11 16:29:14 +02:00
Martin Schwidefsky
457b944b61 s390: extend expoline to BC instructions
[ Upstream commit 6deaa3bbca804b2a3627fd685f75de64da7be535 ]

The BPF JIT uses a 'b <disp>(%r<x>)' instruction in the definition
of the sk_load_word and sk_load_half functions.

Add support for branch-on-condition instructions contained in the
thunk code of an expoline.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-25 16:17:33 +02:00
Martin Schwidefsky
a206c82f9b s390: move spectre sysfs attribute code
[ Upstream commit 4253b0e0627ee3461e64c2495c616f1c8f6b127b ]

The nospec-branch.c file is compiled without the gcc options to
generate expoline thunks. The return branch of the sysfs show
functions cpu_show_spectre_v1 and cpu_show_spectre_v2 is an indirect
branch as well. These need to be compiled with expolines.

Move the sysfs functions for spectre reporting to a separate file
and loose an '.' for one of the messages.

Cc: stable@vger.kernel.org # 4.16
Fixes: d424986f1d ("s390: add sysfs attributes for spectre")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-25 16:17:33 +02:00
Martin Schwidefsky
2a146a9b32 s390/kernel: use expoline for indirect branches
[ Upstream commit c50c84c3ac4d5db683904bdb3257798b6ef980ae ]

The assember code in arch/s390/kernel uses a few more indirect branches
which need to be done with execute trampolines for CONFIG_EXPOLINE=y.

Cc: stable@vger.kernel.org # 4.16
Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-25 16:17:32 +02:00
Martin Schwidefsky
f1bd3b9960 s390/ftrace: use expoline for indirect branches
[ Upstream commit 23a4d7fd34856da8218c4cfc23dba7a6ec0a423a ]

The return from the ftrace_stub, _mcount, ftrace_caller and
return_to_handler functions is done with "br %r14" and "br %r1".
These are indirect branches as well and need to use execute
trampolines for CONFIG_EXPOLINE=y.

The ftrace_caller function is a special case as it returns to the
start of a function and may only use %r0 and %r1. For a pre z10
machine the standard execute trampoline uses a LARL + EX to do
this, but this requires *two* registers in the range %r1..%r15.
To get around this the 'br %r1' located in the lowcore is used,
then the EX instruction does not need an address register.
But the lowcore trick may only be used for pre z14 machines,
with noexec=on the mapping for the first page may not contain
instructions. The solution for that is an ALTERNATIVE in the
expoline THUNK generated by 'GEN_BR_THUNK %r1' to switch to
EXRL, this relies on the fact that a machine that supports
noexec=on has EXRL as well.

Cc: stable@vger.kernel.org # 4.16
Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-25 16:17:32 +02:00
Martin Schwidefsky
e3ad546e60 s390: move expoline assembler macros to a header
[ Upstream commit 6dd85fbb87d1d6b87a3b1f02ca28d7b2abd2e7ba ]

To be able to use the expoline branches in different assembler
files move the associated macros from entry.S to a new header
nospec-insn.h.

While we are at it make the macros a bit nicer to use.

Cc: stable@vger.kernel.org # 4.16
Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-25 16:17:31 +02:00
Martin Schwidefsky
a6565fdd90 s390: remove indirect branch from do_softirq_own_stack
commit 9f18fff63cfd6f559daa1eaae60640372c65f84b upstream.

The inline assembly to call __do_softirq on the irq stack uses
an indirect branch. This can be replaced with a normal relative
branch.

Cc: stable@vger.kernel.org # 4.16
Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-22 18:53:59 +02:00
Hendrik Brueckner
56130d9322 s390/cpum_sf: ensure sample frequency of perf event attributes is non-zero
commit 4bbaf2584b86b0772413edeac22ff448f36351b1 upstream.

Correct a trinity finding for the perf_event_open() system call with
a perf event attribute structure that uses a frequency but has the
sampling frequency set to zero.  This causes a FP divide exception during
the sample rate initialization for the hardware sampling facility.

Fixes: 8c069ff4bd606 ("s390/perf: add support for the CPU-Measurement Sampling Facility")
Cc: stable@vger.kernel.org # 3.14+
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-22 18:53:59 +02:00
Heiko Carstens
c371fe0190 s390/uprobes: implement arch_uretprobe_is_alive()
commit 783c3b53b9506db3e05daacfe34e0287eebb09d8 upstream.

Implement s390 specific arch_uretprobe_is_alive() to avoid SIGSEGVs
observed with uretprobes in combination with setjmp/longjmp.

See commit 2dea1d9c38e4 ("powerpc/uprobes: Implement
arch_uretprobe_is_alive()") for more details.

With this implemented all test cases referenced in the above commit
pass.

Reported-by: Ziqian SUN <zsun@redhat.com>
Cc: <stable@vger.kernel.org> # v4.3+
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:18 +02:00
Martin Schwidefsky
5787b55b50 s390: correct module section names for expoline code revert
[ Upstream commit 6cf09958f32b9667bb3ebadf74367c791112771b ]

The main linker script vmlinux.lds.S for the kernel image merges
the expoline code patch tables into two section ".nospec_call_table"
and ".nospec_return_table". This is *not* done for the modules,
there the sections retain their original names as generated by gcc:
".s390_indirect_call", ".s390_return_mem" and ".s390_return_reg".

The module_finalize code has to check for the compiler generated
section names, otherwise no code patching is done. This slows down
the module code in case of "spectre_v2=off".

Cc: stable@vger.kernel.org # 4.16
Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:16 +02:00
Martin Schwidefsky
f836b34fb0 s390: correct nospec auto detection init order
[ Upstream commit 6a3d1e81a434fc311f224b8be77258bafc18ccc6 ]

With CONFIG_EXPOLINE_AUTO=y the call of spectre_v2_auto_early() via
early_initcall is done *after* the early_param functions. This
overwrites any settings done with the nobp/no_spectre_v2/spectre_v2
parameters. The code patching for the kernel is done after the
evaluation of the early parameters but before the early_initcall
is done. The end result is a kernel image that is patched correctly
but the kernel modules are not.

Make sure that the nospec auto detection function is called before the
early parameters are evaluated and before the code patching is done.

Fixes: 6e179d64126b ("s390: add automatic detection of the spectre defense")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:16 +02:00
Martin Schwidefsky
fce1bf054f s390: add sysfs attributes for spectre
[ Upstream commit d424986f1d6b16079b3231db0314923f4f8deed1 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:15 +02:00
Martin Schwidefsky
68cb884e12 s390: report spectre mitigation via syslog
[ Upstream commit bc035599718412cfba9249aa713f90ef13f13ee9 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:15 +02:00
Martin Schwidefsky
719b84c9ae s390: add automatic detection of the spectre defense
[ Upstream commit 6e179d64126b909f0b288fa63cdbf07c531e9b1d ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:15 +02:00
Martin Schwidefsky
ea1bbd53f0 s390: move nobp parameter functions to nospec-branch.c
[ Upstream commit b2e2f43a01bace1a25bdbae04c9f9846882b727a ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:15 +02:00
Christian Borntraeger
6cdc4b21d2 s390/entry.S: fix spurious zeroing of r0
[ Upstream commit d3f468963cd6fd6d2aa5e26aed8b24232096d0e1 ]

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: 7041d28115e91 ("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>

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:15 +02:00
Martin Schwidefsky
74a93ae5c3 s390: do not bypass BPENTER for interrupt system calls
[ Upstream commit d5feec04fe578c8dbd9e2e1439afc2f0af761ed4 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:15 +02:00
Eugeniu Rosca
6288e169a2 s390: Replace IS_ENABLED(EXPOLINE_*) with IS_ENABLED(CONFIG_EXPOLINE_*)
[ Upstream commit 2cb370d615e9fbed9e95ed222c2c8f337181aa90 ]

I've accidentally stumbled upon the IS_ENABLED(EXPOLINE_*) lines, which
obviously always evaluate to false. Fix this.

Fixes: f19fbd5ed642 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:15 +02:00
Martin Schwidefsky
b609eb65f3 s390: introduce execute-trampolines for branches
[ Upstream commit f19fbd5ed642dc31c809596412dab1ed56f2f156 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:15 +02:00
Martin Schwidefsky
0bd4c47c20 s390: run user space and KVM guests with modified branch prediction
[ Upstream commit 6b73044b2b0081ee3dd1cd6eaab7dee552601efb ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:14 +02:00
Martin Schwidefsky
43cccd87c1 s390: add options to change branch prediction behaviour for the kernel
[ Upstream commit d768bd892fc8f066cd3aa000eb1867bcf32db0ee ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:14 +02:00
Martin Schwidefsky
c257f81b6d s390/alternative: use a copy of the facility bit mask
[ Upstream commit cf1489984641369611556bf00c48f945c77bcf02 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:14 +02:00
Martin Schwidefsky
2ae8b68382 s390: scrub registers on kernel entry and KVM exit
[ Upstream commit 7041d28115e91f2144f811ffe8a195c696b1e1d0 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:14 +02:00
Heiko Carstens
37e7974712 s390: enable CPU alternatives unconditionally
[ Upstream commit 049a2c2d486e8cc82c5cd79fa479c5b105b109e9 ]

Remove the CPU_ALTERNATIVES config option and enable the code
unconditionally. The config option was only added to avoid a conflict
with the named saved segment support. Since that code is gone there is
no reason to keep the CPU_ALTERNATIVES config option.

Just enable it unconditionally to also reduce the number of config
options and make it less likely that something breaks.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:14 +02:00
Vasily Gorbik
b44533a06f s390: introduce CPU alternatives
[ Upstream commit 686140a1a9c41d85a4212a1c26d671139b76404b ]

Implement CPU alternatives, which allows to optionally patch newer
instructions at runtime, based on CPU facilities availability.

A new kernel boot parameter "noaltinstr" disables patching.

Current implementation is derived from x86 alternatives. Although
ideal instructions padding (when altinstr is longer then oldinstr)
is added at compile time, and no oldinstr nops optimization has to be
done at runtime. Also couple of compile time sanity checks are done:
1. oldinstr and altinstr must be <= 254 bytes long,
2. oldinstr and altinstr must not have an odd length.

alternative(oldinstr, altinstr, facility);
alternative_2(oldinstr, altinstr1, facility1, altinstr2, facility2);

Both compile time and runtime padding consists of either 6/4/2 bytes nop
or a jump (brcl) + 2 bytes nop filler if padding is longer then 6 bytes.

.altinstructions and .altinstr_replacement sections are part of
__init_begin : __init_end region and are freed after initialization.

Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:33:14 +02:00
Vasily Gorbik
3da5723b4f s390/ipl: ensure loadparm valid flag is set
commit 15deb080a6087b73089139569558965750e69d67 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-19 08:56:19 +02:00
Eugene Syromiatnikov
27f97375fc s390: fix handling of -1 in set{,fs}[gu]id16 syscalls
commit 6dd0d2d22aa363fec075cb2577ba273ac8462e94 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-22 15:42:17 +01:00
Thomas Richter
18c128456e s390/topology: fix compile error in file arch/s390/kernel/smp.c
[ Upstream commit 38389ec84e835fa31a59b7dabb18343106a6d0d5 ]

Commit 1887aa07b676
("s390/topology: add detection of dedicated vs shared CPUs")
introduced following compiler error when CONFIG_SCHED_TOPOLOGY is not set.

 CC      arch/s390/kernel/smp.o
...
arch/s390/kernel/smp.c: In function ‘smp_start_secondary’:
arch/s390/kernel/smp.c:812:6: error: implicit declaration of function
	‘topology_cpu_dedicated’; did you mean ‘topology_cpu_init’?

This patch fixes the compiler error by adding function
topology_cpu_dedicated() to return false when this config option is
not defined.

Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-03 17:38:59 +01:00
Thiago Rafael Becker
c5d9b78d53 kernel: make groups_sort calling a responsibility group_info allocators
commit bdcf0a423ea1c40bbb40e7ee483b50fc8aa3d758 upstream.

In testing, we found that nfsd threads may call set_groups in parallel
for the same entry cached in auth.unix.gid, racing in the call of
groups_sort, corrupting the groups for that entry and leading to
permission denials for the client.

This patch:
 - Make groups_sort globally visible.
 - Move the call to groups_sort to the modifiers of group_info
 - Remove the call to groups_sort from set_groups

Link: http://lkml.kernel.org/r/20171211151420.18655-1-thiago.becker@gmail.com
Signed-off-by: Thiago Rafael Becker <thiago.becker@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Acked-by: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-20 10:10:18 +01:00
Heiko Carstens
0fad60d717 s390: fix compat system call table
commit e779498df587dd2189b30fe5b9245aefab870eb8 upstream.

When wiring up the socket system calls the compat entries were
incorrectly set. Not all of them point to the corresponding compat
wrapper functions, which clear the upper 33 bits of user space
pointers, like it is required.

Fixes: 977108f89c989 ("s390: wire up separate socketcalls system calls")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-14 09:52:56 +01:00
Heiko Carstens
a9f359f24c s390/ptrace: fix guarded storage regset handling
[ Upstream commit 5ef2d5231d547c672c67bdf84c13a4adaf477964 ]

If the guarded storage regset for current is supposed to be changed,
the regset from user space is copied directly into the guarded storage
control block.

If then the process gets scheduled away while the control block is
being copied and before the new control block has been loaded, the
result is random: the process can be scheduled away due to a page
fault or preemption. If that happens the already copied parts will be
overwritten by save_gs_cb(), called from switch_to().

Avoid this by copying the data to a temporary buffer on the stack and
do the actual update with preemption disabled.

Fixes: f5bbd7219891 ("s390/ptrace: guarded storage regset for the current task")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-10 13:40:43 +01:00
Heiko Carstens
b8e212c599 s390/runtime instrumentation: simplify task exit handling
commit 8d9047f8b967ce6181fd824ae922978e1b055cc0 upstream.

Free data structures required for runtime instrumentation from
arch_release_task_struct(). This allows to simplify the code a bit,
and also makes the semantics a bit easier: arch_release_task_struct()
is never called from the task that is being removed.

In addition this allows to get rid of exit_thread() in a later patch.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-10 13:40:37 +01:00
Vasily Gorbik
6047980008 s390/disassembler: increase show_code buffer size
commit b192571d1ae375e0bbe0aa3ccfa1a3c3704454b9 upstream.

Current buffer size of 64 is too small. objdump shows that there are
instructions which would require up to 75 bytes buffer (with current
formating). 128 bytes "ought to be enough for anybody".

Also replaces 8 spaces with a single tab to reduce the memory footprint.

Fixes the following KASAN finding:

BUG: KASAN: stack-out-of-bounds in number+0x3fe/0x538
Write of size 1 at addr 000000005a4a75a0 by task bash/1282

CPU: 1 PID: 1282 Comm: bash Not tainted 4.14.0+ #215
Hardware name: IBM 2964 N96 702 (z/VM 6.4.0)
Call Trace:
([<000000000011eeb6>] show_stack+0x56/0x88)
 [<0000000000e1ce1a>] dump_stack+0x15a/0x1b0
 [<00000000004e2994>] print_address_description+0xf4/0x288
 [<00000000004e2cf2>] kasan_report+0x13a/0x230
 [<0000000000e38ae6>] number+0x3fe/0x538
 [<0000000000e3dfe4>] vsnprintf+0x194/0x948
 [<0000000000e3ea42>] sprintf+0xa2/0xb8
 [<00000000001198dc>] print_insn+0x374/0x500
 [<0000000000119346>] show_code+0x4ee/0x538
 [<000000000011f234>] show_registers+0x34c/0x388
 [<000000000011f2ae>] show_regs+0x3e/0xa8
 [<000000000011f502>] die+0x1ea/0x2e8
 [<0000000000138f0e>] do_no_context+0x106/0x168
 [<0000000000139a1a>] do_protection_exception+0x4da/0x7d0
 [<0000000000e55914>] pgm_check_handler+0x16c/0x1c0
 [<000000000090639e>] sysrq_handle_crash+0x46/0x58
([<0000000000000007>] 0x7)
 [<00000000009073fa>] __handle_sysrq+0x102/0x218
 [<0000000000907c06>] write_sysrq_trigger+0xd6/0x100
 [<000000000061d67a>] proc_reg_write+0xb2/0x128
 [<0000000000520be6>] __vfs_write+0xee/0x368
 [<0000000000521222>] vfs_write+0x21a/0x278
 [<000000000052156a>] SyS_write+0xda/0x178
 [<0000000000e555cc>] system_call+0xc4/0x270

The buggy address belongs to the page:
page:000003d1016929c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x0()
raw: 0000000000000000 0000000000000000 0000000000000000 ffffffff00000000
raw: 0000000000000100 0000000000000200 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 000000005a4a7480: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
 000000005a4a7500: 00 00 00 00 00 00 00 00 f2 f2 f2 f2 00 00 00 00
>000000005a4a7580: 00 00 00 00 f3 f3 f3 f3 00 00 00 00 00 00 00 00
                               ^
 000000005a4a7600: 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 f8 f8
 000000005a4a7680: f2 f2 f2 f2 f2 f2 f8 f8 f2 f2 f3 f3 f3 f3 00 00
==================================================================

Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30 08:40:38 +00:00
Heiko Carstens
15e82cdb4d s390/disassembler: add missing end marker for e7 table
commit 5c50538752af7968f53924b22dede8ed4ce4cb3b upstream.

The e7 opcode table does not have an end marker. Hence when trying to
find an unknown e7 instruction the code will access memory behind the
table until it finds something that matches the opcode, or the kernel
crashes, whatever comes first.

This affects not only the in-kernel disassembler but also uprobes and
kprobes which refuse to set a probe on unknown instructions, and
therefore search the opcode tables to figure out if instructions are
known or not.

Fixes: 3585cb0280654 ("s390/disassembler: add vector instructions")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30 08:40:38 +00:00
Heiko Carstens
7ee3f026ae s390/guarded storage: fix possible memory corruption
commit fa1edf3f63c05ca8eacafcd7048ed91e5360f1a8 upstream.

For PREEMPT enabled kernels the guarded storage (GS) code contains a
possible use-after-free bug. If a task that makes use of GS exits, it
will execute do_exit() while still enabled for preemption.

That function will call exit_thread_runtime_instr() via exit_thread().
If exit_thread_gs() gets preempted after the GS control block of the
task has been freed but before the pointer to it is set to NULL, then
save_gs_cb(), called from switch_to(), will write to already freed
memory.

Avoid this and simply disable preemption while freeing the control
block and setting the pointer to NULL.

Fixes: 916cda1aa1b4 ("s390: add a system call for guarded storage")
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30 08:40:38 +00:00
Heiko Carstens
27576413d9 s390/runtime instrumention: fix possible memory corruption
commit d6e646ad7cfa7034d280459b2b2546288f247144 upstream.

For PREEMPT enabled kernels the runtime instrumentation (RI) code
contains a possible use-after-free bug. If a task that makes use of RI
exits, it will execute do_exit() while still enabled for preemption.

That function will call exit_thread_runtime_instr() via
exit_thread(). If exit_thread_runtime_instr() gets preempted after the
RI control block of the task has been freed but before the pointer to
it is set to NULL, then save_ri_cb(), called from switch_to(), will
write to already freed memory.

Avoid this and simply disable preemption while freeing the control
block and setting the pointer to NULL.

Fixes: e4b8b3f33fca ("s390: add support for runtime instrumentation")
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30 08:40:38 +00:00
Heiko Carstens
21caac65d2 s390/noexec: execute kexec datamover without DAT
commit d0e810eeb3d326978f248b8f0233a2f30f58c72d upstream.

Rebooting into a new kernel with kexec fails (system dies) if tried on
a machine that has no-execute support. Reason for this is that the so
called datamover code gets executed with DAT on (MMU is active) and
the page that contains the datamover is marked as non-executable.
Therefore when branching into the datamover an unexpected program
check happens and afterwards the machine is dead.

This can be simply avoided by disabling DAT, which also disables any
no-execute checks, just before the datamover gets executed.

In fact the first thing done by the datamover is to disable DAT. The
code in the datamover that disables DAT can be removed as well.

Thanks to Michael Holzheu and Gerald Schaefer for tracking this down.

Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fixes: 57d7f939e7bd ("s390: add no-execute support")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30 08:40:38 +00:00
Heiko Carstens
236f6e7283 s390: fix transactional execution control register handling
commit a1c5befc1c24eb9c1ee83f711e0f21ee79cbb556 upstream.

Dan Horák reported the following crash related to transactional execution:

User process fault: interruption code 0013 ilc:3 in libpthread-2.26.so[3ff93c00000+1b000]
CPU: 2 PID: 1 Comm: /init Not tainted 4.13.4-300.fc27.s390x #1
Hardware name: IBM 2827 H43 400 (z/VM 6.4.0)
task: 00000000fafc8000 task.stack: 00000000fafc4000
User PSW : 0705200180000000 000003ff93c14e70
           R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:1 AS:0 CC:2 PM:0 RI:0 EA:3
User GPRS: 0000000000000077 000003ff00000000 000003ff93144d48 000003ff93144d5e
           0000000000000000 0000000000000002 0000000000000000 000003ff00000000
           0000000000000000 0000000000000418 0000000000000000 000003ffcc9fe770
           000003ff93d28f50 000003ff9310acf0 000003ff92b0319a 000003ffcc9fe6d0
User Code: 000003ff93c14e62: 60e0b030            std     %f14,48(%r11)
           000003ff93c14e66: 60f0b038            std     %f15,56(%r11)
          #000003ff93c14e6a: e5600000ff0e        tbegin  0,65294
          >000003ff93c14e70: a7740006            brc     7,3ff93c14e7c
           000003ff93c14e74: a7080000            lhi     %r0,0
           000003ff93c14e78: a7f40023            brc     15,3ff93c14ebe
           000003ff93c14e7c: b2220000            ipm     %r0
           000003ff93c14e80: 8800001c            srl     %r0,28

There are several bugs with control register handling with respect to
transactional execution:

- on task switch update_per_regs() is only called if the next task has
  an mm (is not a kernel thread). This however is incorrect. This
  breaks e.g. for user mode helper handling, where the kernel creates
  a kernel thread and then execve's a user space program. Control
  register contents related to transactional execution won't be
  updated on execve. If the previous task ran with transactional
  execution disabled then the new task will also run with
  transactional execution disabled, which is incorrect. Therefore call
  update_per_regs() unconditionally within switch_to().

- on startup the transactional execution facility is not enabled for
  the idle thread. This is not really a bug, but an inconsistency to
  other facilities. Therefore enable the facility if it is available.

- on fork the new thread's per_flags field is not cleared. This means
  that a child process inherits the PER_FLAG_NO_TE flag. This flag can
  be set with a ptrace request to disable transactional execution for
  the current process. It should not be inherited by new child
  processes in order to be consistent with the handling of all other
  PER related debugging options. Therefore clear the per_flags field in
  copy_thread_tls().

Reported-and-tested-by: Dan Horák <dan@danny.cz>
Fixes: d35339a42dd1 ("s390: add support for transactional memory")
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30 08:40:38 +00:00
Linus Torvalds
ead751507d License cleanup: add SPDX license identifiers to some files
Many source files in the tree are missing licensing information, which
 makes it harder for compliance tools to determine the correct license.
 
 By default all files without license information are under the default
 license of the kernel, which is GPL version 2.
 
 Update the files which contain no license information with the 'GPL-2.0'
 SPDX license identifier.  The SPDX identifier is a legally binding
 shorthand, which can be used instead of the full boiler plate text.
 
 This patch is based on work done by Thomas Gleixner and Kate Stewart and
 Philippe Ombredanne.
 
 How this work was done:
 
 Patches were generated and checked against linux-4.14-rc6 for a subset of
 the use cases:
  - file had no licensing information it it.
  - file was a */uapi/* one with no licensing information in it,
  - file was a */uapi/* one with existing licensing information,
 
 Further patches will be generated in subsequent months to fix up cases
 where non-standard license headers were used, and references to license
 had to be inferred by heuristics based on keywords.
 
 The analysis to determine which SPDX License Identifier to be applied to
 a file was done in a spreadsheet of side by side results from of the
 output of two independent scanners (ScanCode & Windriver) producing SPDX
 tag:value files created by Philippe Ombredanne.  Philippe prepared the
 base worksheet, and did an initial spot review of a few 1000 files.
 
 The 4.13 kernel was the starting point of the analysis with 60,537 files
 assessed.  Kate Stewart did a file by file comparison of the scanner
 results in the spreadsheet to determine which SPDX license identifier(s)
 to be applied to the file. She confirmed any determination that was not
 immediately clear with lawyers working with the Linux Foundation.
 
 Criteria used to select files for SPDX license identifier tagging was:
  - Files considered eligible had to be source code files.
  - Make and config files were included as candidates if they contained >5
    lines of source
  - File already had some variant of a license header in it (even if <5
    lines).
 
 All documentation files were explicitly excluded.
 
 The following heuristics were used to determine which SPDX license
 identifiers to apply.
 
  - when both scanners couldn't find any license traces, file was
    considered to have no license information in it, and the top level
    COPYING file license applied.
 
    For non */uapi/* files that summary was:
 
    SPDX license identifier                            # files
    ---------------------------------------------------|-------
    GPL-2.0                                              11139
 
    and resulted in the first patch in this series.
 
    If that file was a */uapi/* path one, it was "GPL-2.0 WITH
    Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
 
    SPDX license identifier                            # files
    ---------------------------------------------------|-------
    GPL-2.0 WITH Linux-syscall-note                        930
 
    and resulted in the second patch in this series.
 
  - if a file had some form of licensing information in it, and was one
    of the */uapi/* ones, it was denoted with the Linux-syscall-note if
    any GPL family license was found in the file or had no licensing in
    it (per prior point).  Results summary:
 
    SPDX license identifier                            # files
    ---------------------------------------------------|------
    GPL-2.0 WITH Linux-syscall-note                       270
    GPL-2.0+ WITH Linux-syscall-note                      169
    ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
    ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
    LGPL-2.1+ WITH Linux-syscall-note                      15
    GPL-1.0+ WITH Linux-syscall-note                       14
    ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
    LGPL-2.0+ WITH Linux-syscall-note                       4
    LGPL-2.1 WITH Linux-syscall-note                        3
    ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
    ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
 
    and that resulted in the third patch in this series.
 
  - when the two scanners agreed on the detected license(s), that became
    the concluded license(s).
 
  - when there was disagreement between the two scanners (one detected a
    license but the other didn't, or they both detected different
    licenses) a manual inspection of the file occurred.
 
  - In most cases a manual inspection of the information in the file
    resulted in a clear resolution of the license that should apply (and
    which scanner probably needed to revisit its heuristics).
 
  - When it was not immediately clear, the license identifier was
    confirmed with lawyers working with the Linux Foundation.
 
  - If there was any question as to the appropriate license identifier,
    the file was flagged for further research and to be revisited later
    in time.
 
 In total, over 70 hours of logged manual review was done on the
 spreadsheet to determine the SPDX license identifiers to apply to the
 source files by Kate, Philippe, Thomas and, in some cases, confirmation
 by lawyers working with the Linux Foundation.
 
 Kate also obtained a third independent scan of the 4.13 code base from
 FOSSology, and compared selected files where the other two scanners
 disagreed against that SPDX file, to see if there was new insights.  The
 Windriver scanner is based on an older version of FOSSology in part, so
 they are related.
 
 Thomas did random spot checks in about 500 files from the spreadsheets
 for the uapi headers and agreed with SPDX license identifier in the
 files he inspected. For the non-uapi files Thomas did random spot checks
 in about 15000 files.
 
 In initial set of patches against 4.14-rc6, 3 files were found to have
 copy/paste license identifier errors, and have been fixed to reflect the
 correct identifier.
 
 Additionally Philippe spent 10 hours this week doing a detailed manual
 inspection and review of the 12,461 patched files from the initial patch
 version early this week with:
  - a full scancode scan run, collecting the matched texts, detected
    license ids and scores
  - reviewing anything where there was a license detected (about 500+
    files) to ensure that the applied SPDX license was correct
  - reviewing anything where there was no detection but the patch license
    was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
    SPDX license was correct
 
 This produced a worksheet with 20 files needing minor correction.  This
 worksheet was then exported into 3 different .csv files for the
 different types of files to be modified.
 
 These .csv files were then reviewed by Greg.  Thomas wrote a script to
 parse the csv files and add the proper SPDX tag to the file, in the
 format that the file expected.  This script was further refined by Greg
 based on the output to detect more types of files automatically and to
 distinguish between header and source .c files (which need different
 comment types.)  Finally Greg ran the script using the .csv files to
 generate the patches.
 
 Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
 Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
 Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx_identifiers-4.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull initial SPDX identifiers from Greg KH:
 "License cleanup: add SPDX license identifiers to some files

  Many source files in the tree are missing licensing information, which
  makes it harder for compliance tools to determine the correct license.

  By default all files without license information are under the default
  license of the kernel, which is GPL version 2.

  Update the files which contain no license information with the
  'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally
  binding shorthand, which can be used instead of the full boiler plate
  text.

  This patch is based on work done by Thomas Gleixner and Kate Stewart
  and Philippe Ombredanne.

  How this work was done:

  Patches were generated and checked against linux-4.14-rc6 for a subset
  of the use cases:

   - file had no licensing information it it.

   - file was a */uapi/* one with no licensing information in it,

   - file was a */uapi/* one with existing licensing information,

  Further patches will be generated in subsequent months to fix up cases
  where non-standard license headers were used, and references to
  license had to be inferred by heuristics based on keywords.

  The analysis to determine which SPDX License Identifier to be applied
  to a file was done in a spreadsheet of side by side results from of
  the output of two independent scanners (ScanCode & Windriver)
  producing SPDX tag:value files created by Philippe Ombredanne.
  Philippe prepared the base worksheet, and did an initial spot review
  of a few 1000 files.

  The 4.13 kernel was the starting point of the analysis with 60,537
  files assessed. Kate Stewart did a file by file comparison of the
  scanner results in the spreadsheet to determine which SPDX license
  identifier(s) to be applied to the file. She confirmed any
  determination that was not immediately clear with lawyers working with
  the Linux Foundation.

  Criteria used to select files for SPDX license identifier tagging was:

   - Files considered eligible had to be source code files.

   - Make and config files were included as candidates if they contained
     >5 lines of source

   - File already had some variant of a license header in it (even if <5
     lines).

  All documentation files were explicitly excluded.

  The following heuristics were used to determine which SPDX license
  identifiers to apply.

   - when both scanners couldn't find any license traces, file was
     considered to have no license information in it, and the top level
     COPYING file license applied.

     For non */uapi/* files that summary was:

       SPDX license identifier                            # files
       ---------------------------------------------------|-------
       GPL-2.0                                              11139

     and resulted in the first patch in this series.

     If that file was a */uapi/* path one, it was "GPL-2.0 WITH
     Linux-syscall-note" otherwise it was "GPL-2.0". Results of that
     was:

       SPDX license identifier                            # files
       ---------------------------------------------------|-------
       GPL-2.0 WITH Linux-syscall-note                        930

     and resulted in the second patch in this series.

   - if a file had some form of licensing information in it, and was one
     of the */uapi/* ones, it was denoted with the Linux-syscall-note if
     any GPL family license was found in the file or had no licensing in
     it (per prior point). Results summary:

       SPDX license identifier                            # files
       ---------------------------------------------------|------
       GPL-2.0 WITH Linux-syscall-note                       270
       GPL-2.0+ WITH Linux-syscall-note                      169
       ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
       ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
       LGPL-2.1+ WITH Linux-syscall-note                      15
       GPL-1.0+ WITH Linux-syscall-note                       14
       ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
       LGPL-2.0+ WITH Linux-syscall-note                       4
       LGPL-2.1 WITH Linux-syscall-note                        3
       ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
       ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

     and that resulted in the third patch in this series.

   - when the two scanners agreed on the detected license(s), that
     became the concluded license(s).

   - when there was disagreement between the two scanners (one detected
     a license but the other didn't, or they both detected different
     licenses) a manual inspection of the file occurred.

   - In most cases a manual inspection of the information in the file
     resulted in a clear resolution of the license that should apply
     (and which scanner probably needed to revisit its heuristics).

   - When it was not immediately clear, the license identifier was
     confirmed with lawyers working with the Linux Foundation.

   - If there was any question as to the appropriate license identifier,
     the file was flagged for further research and to be revisited later
     in time.

  In total, over 70 hours of logged manual review was done on the
  spreadsheet to determine the SPDX license identifiers to apply to the
  source files by Kate, Philippe, Thomas and, in some cases,
  confirmation by lawyers working with the Linux Foundation.

  Kate also obtained a third independent scan of the 4.13 code base from
  FOSSology, and compared selected files where the other two scanners
  disagreed against that SPDX file, to see if there was new insights.
  The Windriver scanner is based on an older version of FOSSology in
  part, so they are related.

  Thomas did random spot checks in about 500 files from the spreadsheets
  for the uapi headers and agreed with SPDX license identifier in the
  files he inspected. For the non-uapi files Thomas did random spot
  checks in about 15000 files.

  In initial set of patches against 4.14-rc6, 3 files were found to have
  copy/paste license identifier errors, and have been fixed to reflect
  the correct identifier.

  Additionally Philippe spent 10 hours this week doing a detailed manual
  inspection and review of the 12,461 patched files from the initial
  patch version early this week with:

   - a full scancode scan run, collecting the matched texts, detected
     license ids and scores

   - reviewing anything where there was a license detected (about 500+
     files) to ensure that the applied SPDX license was correct

   - reviewing anything where there was no detection but the patch
     license was not GPL-2.0 WITH Linux-syscall-note to ensure that the
     applied SPDX license was correct

  This produced a worksheet with 20 files needing minor correction. This
  worksheet was then exported into 3 different .csv files for the
  different types of files to be modified.

  These .csv files were then reviewed by Greg. Thomas wrote a script to
  parse the csv files and add the proper SPDX tag to the file, in the
  format that the file expected. This script was further refined by Greg
  based on the output to detect more types of files automatically and to
  distinguish between header and source .c files (which need different
  comment types.) Finally Greg ran the script using the .csv files to
  generate the patches.

  Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
  Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
  Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'spdx_identifiers-4.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  License cleanup: add SPDX license identifier to uapi header files with a license
  License cleanup: add SPDX license identifier to uapi header files with no license
  License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 10:04:46 -07:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00