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commit db7bee653859ef7179be933e7d1384644f795f26 upstream.
Currently the JIT completely removes things like `reg32 += 0`,
however, the BPF_ALU semantics requires the target register to be
zero-extended in such cases.
Fix by optimizing out only the arithmetic operation, but not the
subsequent zero-extension.
Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6e61dc9da0b7a0d91d57c2e20b5ea4fd2d4e7e53 upstream.
The JIT uses agfi for subtracting constants, but -(-0x80000000) cannot
be represented as a 32-bit signed binary integer. Fix by using algfi in
this particular case.
Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5492886c14744d239e87f1b0b774b5a341e755cc ]
In case of a jump label print the real address of the piece of code
where a mismatch was detected. This is right before the system panics,
so there is nothing revealed.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 26f4e759ef9b8a2bab1823d692ed6d56d40b66e3 upstream.
176.718956 Krnl Code: 00000000004d38b0: a54c0018 llihh %r4,24
176.718956 00000000004d38b4: b9080014 agr %r1,%r4
^
Using a tab to align disassembly lines which follow the first line with
"Krnl Code: " doesn't always work, e.g. if there is a prefix (timestamp
or syslog prefix) which is not 8 chars aligned. Go back to alignment
with spaces.
Fixes: b192571d1ae3 ("s390/disassembler: increase show_code buffer size")
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>
[ Upstream commit 91091656252f5d6d8c476e0c92776ce9fae7b445 ]
Currently array jit->seen_reg[r1] is being accessed before the range
checking of index r1. The range changing on r1 should be performed
first since it will avoid any potential out-of-range accesses on the
array seen_reg[] and also it is more optimal to perform checks on r1
before fetching data from the array. Fix this by swapping the order
of the checks before the array access.
Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/bpf/20210715125712.24690-1-colin.king@canonical.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b7d91d230a119fdcc334d10c9889ce9c5e15118b ]
Console name reported in /proc/consoles:
ttyS1 -W- (EC p ) 4:65
does not match the char device name:
crw--w---- 1 root root 4, 65 May 17 12:18 /dev/ttysclp0
so debian-installer inside a QEMU s390x instance gets confused and fails
to start with the following error:
steal-ctty: No such file or directory
Signed-off-by: Valentin Vidic <vvidic@valentin-vidic.from.hr>
Link: https://lore.kernel.org/r/20210427194010.9330-1-vvidic@valentin-vidic.from.hr
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5d3516b3647621d5a1180672ea9e0817fb718ada ]
APPLDATA_BASE should depend on PROC_SYSCTL instead of PROC_FS.
Building with PROC_FS but not PROC_SYSCTL causes a build error,
since appldata_base.c uses data and APIs from fs/proc/proc_sysctl.c.
arch/s390/appldata/appldata_base.o: in function `appldata_generic_handler':
appldata_base.c:(.text+0x192): undefined reference to `sysctl_vals'
Fixes: c185b783b099 ("[S390] Remove config options.")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20210528002420.17634-1-rdunlap@infradead.org
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a994eddb947ea9ebb7b14d9a1267001699f0a136 ]
Currently psw_idle does not allocate a stack frame and does not
save its r14 and r15 into the save area. Even though this is valid from
call ABI point of view, because psw_idle does not make any calls
explicitly, in reality psw_idle is an entry point for controlled
transition into serving interrupts. So, in practice, psw_idle stack
frame is analyzed during stack unwinding. Depending on build options
that r14 slot in the save area of psw_idle might either contain a value
saved by previous sibling call or complete garbage.
[task 0000038000003c28] do_ext_irq+0xd6/0x160
[task 0000038000003c78] ext_int_handler+0xba/0xe8
[task *0000038000003dd8] psw_idle_exit+0x0/0x8 <-- pt_regs
([task 0000038000003dd8] 0x0)
[task 0000038000003e10] default_idle_call+0x42/0x148
[task 0000038000003e30] do_idle+0xce/0x160
[task 0000038000003e70] cpu_startup_entry+0x36/0x40
[task 0000038000003ea0] arch_call_rest_init+0x76/0x80
So, to make a stacktrace nicer and actually point for the real caller of
psw_idle in this frequently occurring case, make psw_idle save its r14.
[task 0000038000003c28] do_ext_irq+0xd6/0x160
[task 0000038000003c78] ext_int_handler+0xba/0xe8
[task *0000038000003dd8] psw_idle_exit+0x0/0x6 <-- pt_regs
([task 0000038000003dd8] arch_cpu_idle+0x3c/0xd0)
[task 0000038000003e10] default_idle_call+0x42/0x148
[task 0000038000003e30] do_idle+0xce/0x160
[task 0000038000003e70] cpu_startup_entry+0x36/0x40
[task 0000038000003ea0] arch_call_rest_init+0x76/0x80
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 62c8dca9e194326802b43c60763f856d782b225c ]
Avoid a potentially large stack frame and overflow by making
"cpumask_t avail" a static variable. There is no concurrent
access due to the existing locking.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 78d732e1f326f74f240d416af9484928303d9951 upstream.
This file is installed by the s390 CPU Measurement sampling
facility device driver to export supported minimum and
maximum sample buffer sizes.
This file is read by lscpumf tool to display the details
of the device driver capabilities. The lscpumf tool might
be invoked by a non-root user. In this case it does not
print anything because the file contents can not be read.
Fix this by allowing read access for all users. Reading
the file contents is ok, changing the file contents is
left to the root user only.
For further reference and details see:
[1] https://github.com/ibm-s390-tools/s390-tools/issues/97
Fixes: 69f239ed335a ("s390/cpum_sf: Dynamically extend the sampling buffer if overflows occur")
Cc: <stable@vger.kernel.org> # 3.14
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit fcb2b70cdb194157678fb1a75f9ff499aeba3d2a ]
Add __init to reserve_memory_end, reserve_oldmem and remove_oldmem.
Sometimes these functions are not inlined, and then the build
complains about section mismatch.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 528a9539348a0234375dfaa1ca5dbbb2f8f8e8d2 upstream.
If the pmd is soft dirty we must mark the pte as soft dirty (and not dirty).
This fixes some cases for guest migration with huge page backings.
Cc: <stable@vger.kernel.org> # 4.8
Fixes: bc29b7ac1d9f ("s390/mm: clean up pte/pmd encoding")
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 998f5bbe3dbdab81c1cfb1aef7c3892f5d24f6c7 ]
Currently if early_pgm_check_handler is called it ends up in pgm check
loop. The problem is that early_pgm_check_handler is instrumented by
KASAN but executed without DAT flag enabled which leads to addressing
exception when KASAN checks try to access shadow memory.
Fix that by executing early handlers with DAT flag on under KASAN as
expected.
Reported-and-tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 774911290c589e98e3638e73b24b0a4d4530e97c ]
The current number of KVM_IRQCHIP_NUM_PINS results in an order 3
allocation (32kb) for each guest start/restart. This can result in OOM
killer activity even with free swap when the memory is fragmented
enough:
kernel: qemu-system-s39 invoked oom-killer: gfp_mask=0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_COMP|__GFP_ZERO), order=3, oom_score_adj=0
kernel: CPU: 1 PID: 357274 Comm: qemu-system-s39 Kdump: loaded Not tainted 5.4.0-29-generic #33-Ubuntu
kernel: Hardware name: IBM 8562 T02 Z06 (LPAR)
kernel: Call Trace:
kernel: ([<00000001f848fe2a>] show_stack+0x7a/0xc0)
kernel: [<00000001f8d3437a>] dump_stack+0x8a/0xc0
kernel: [<00000001f8687032>] dump_header+0x62/0x258
kernel: [<00000001f8686122>] oom_kill_process+0x172/0x180
kernel: [<00000001f8686abe>] out_of_memory+0xee/0x580
kernel: [<00000001f86e66b8>] __alloc_pages_slowpath+0xd18/0xe90
kernel: [<00000001f86e6ad4>] __alloc_pages_nodemask+0x2a4/0x320
kernel: [<00000001f86b1ab4>] kmalloc_order+0x34/0xb0
kernel: [<00000001f86b1b62>] kmalloc_order_trace+0x32/0xe0
kernel: [<00000001f84bb806>] kvm_set_irq_routing+0xa6/0x2e0
kernel: [<00000001f84c99a4>] kvm_arch_vm_ioctl+0x544/0x9e0
kernel: [<00000001f84b8936>] kvm_vm_ioctl+0x396/0x760
kernel: [<00000001f875df66>] do_vfs_ioctl+0x376/0x690
kernel: [<00000001f875e304>] ksys_ioctl+0x84/0xb0
kernel: [<00000001f875e39a>] __s390x_sys_ioctl+0x2a/0x40
kernel: [<00000001f8d55424>] system_call+0xd8/0x2c8
As far as I can tell s390x does not use the iopins as we bail our for
anything other than KVM_IRQ_ROUTING_S390_ADAPTER and the chip/pin is
only used for KVM_IRQ_ROUTING_IRQCHIP. So let us use a small number to
reduce the memory footprint.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200617083620.5409-1-borntraeger@de.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 873e5a763d604c32988c4a78913a8dab3862d2f9 ]
When strace wants to update the syscall number, it sets GPR2
to the desired number and updates the GPR via PTRACE_SETREGSET.
It doesn't update regs->int_code which would cause the old syscall
executed on syscall restart. As we cannot change the ptrace ABI and
don't have a field for the interruption code, check whether the tracee
is in a syscall and the last instruction was svc. In that case assume
that the tracer wants to update the syscall number and copy the GPR2
value to regs->int_code.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit b3583fca5fb654af2cfc1c08259abb9728272538 upstream.
If both the tracer and the tracee are compat processes, and gprs[2]
is assigned a value by __poke_user_compat, then the higher 32 bits
of gprs[2] are cleared, IS_ERR_VALUE() always returns false, and
syscall_get_error() always returns 0.
Fix the implementation by sign-extending the value for compat processes
the same way as x86 implementation does.
The bug was exposed to user space by commit 201766a20e30f ("ptrace: add
PTRACE_GET_SYSCALL_INFO request") and detected by strace test suite.
This change fixes strace syscall tampering on s390.
Link: https://lkml.kernel.org/r/20200602180051.GA2427@altlinux.org
Fixes: 753c4dd6a2fa2 ("[S390] ptrace changes")
Cc: Elvira Khabirova <lineprinter@altlinux.org>
Cc: stable@vger.kernel.org # v2.6.28+
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b4adfe55915d8363e244e42386d69567db1719b9 ]
A typical backtrace acquired from ftraced function currently looks like
the following (e.g. for "path_openat"):
arch_stack_walk+0x15c/0x2d8
stack_trace_save+0x50/0x68
stack_trace_call+0x15a/0x3b8
ftrace_graph_caller+0x0/0x1c
0x3e0007e3c98 <- ftraced function caller (should be do_filp_open+0x7c/0xe8)
do_open_execat+0x70/0x1b8
__do_execve_file.isra.0+0x7d8/0x860
__s390x_sys_execve+0x56/0x68
system_call+0xdc/0x2d8
Note random "0x3e0007e3c98" stack value as ftraced function caller. This
value causes either imprecise unwinder result or unwinding failure.
That "0x3e0007e3c98" comes from r14 of ftraced function stack frame, which
it haven't had a chance to initialize since the very first instruction
calls ftrace code ("ftrace_caller"). (ftraced function might never
save r14 as well). Nevertheless according to s390 ABI any function
is called with stack frame allocated for it and r14 contains return
address. "ftrace_caller" itself is called with "brasl %r0,ftrace_caller".
So, to fix this issue simply always save traced function caller onto
ftraced function stack frame.
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1493e0f944f3c319d11e067c185c904d01c17ae5 ]
We have to properly retry again by returning -EINVAL immediately in case
somebody else instantiated the table concurrently. We missed to add the
goto in this function only. The code now matches the other, similar
shadowing functions.
We are overwriting an existing region 2 table entry. All allocated pages
are added to the crst_list to be freed later, so they are not lost
forever. However, when unshadowing the region 2 table, we wouldn't trigger
unshadowing of the original shadowed region 3 table that we replaced. It
would get unshadowed when the original region 3 table is modified. As it's
not connected to the page table hierarchy anymore, it's not going to get
used anymore. However, for a limited time, this page table will stick
around, so it's in some sense a temporary memory leak.
Identified by manual code inspection. I don't think this classifies as
stable material.
Fixes: 998f637cc4b9 ("s390/mm: avoid races on region/segment/page table shadowing")
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200403153050.20569-4-david@redhat.com
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6c7c851f1b666a8a455678a0b480b9162de86052 upstream.
Show the full diag statistic table and not just parts of it.
The issue surfaced in a KVM guest with a number of vcpus
defined smaller than NR_DIAG_STAT.
Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Mueller <mimu@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4d4cee96fb7a3cc53702a9be8299bf525be4ee98 upstream.
Whenever we get an -EFAULT, we failed to read in guest 2 physical
address space. Such addressing exceptions are reported via a program
intercept to the nested hypervisor.
We faked the intercept, we have to return to guest 2. Instead, right
now we would be returning -EFAULT from the intercept handler, eventually
crashing the VM.
the correct thing to do is to return 1 as rc == 1 is the internal
representation of "we have to go back into g2".
Addressing exceptions can only happen if the g2->g3 page tables
reference invalid g2 addresses (say, either a table or the final page is
not accessible - so something that basically never happens in sane
environments.
Identified by manual code inspection.
Fixes: a3508fbe9dc6 ("KVM: s390: vsie: initial support for nested virtualization")
Cc: <stable@vger.kernel.org> # v4.8+
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200403153050.20569-3-david@redhat.com
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
[borntraeger@de.ibm.com: fix patch description]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a1d032a49522cb5368e5dfb945a85899b4c74f65 upstream.
In case we have a region 1 the following calculation
(31 + ((gmap->asce & _ASCE_TYPE_MASK) >> 2)*11)
results in 64. As shifts beyond the size are undefined the compiler is
free to use instructions like sllg. sllg will only use 6 bits of the
shift value (here 64) resulting in no shift at all. That means that ALL
addresses will be rejected.
The can result in endless loops, e.g. when prefix cannot get mapped.
Fixes: 4be130a08420 ("s390/mm: add shadow gmap support")
Tested-by: Janosch Frank <frankja@linux.ibm.com>
Reported-by: Janosch Frank <frankja@linux.ibm.com>
Cc: <stable@vger.kernel.org> # v4.8+
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200403153050.20569-2-david@redhat.com
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
[borntraeger@de.ibm.com: fix patch description, remove WARN_ON_ONCE]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 380324734956c64cd060e1db4304f3117ac15809 upstream.
Clang warns:
In file included from ../arch/s390/purgatory/purgatory.c:10:
In file included from ../include/linux/kexec.h:18:
In file included from ../include/linux/crash_core.h:6:
In file included from ../include/linux/elfcore.h:5:
In file included from ../include/linux/user.h:1:
In file included from ../arch/s390/include/asm/user.h:11:
../arch/s390/include/asm/page.h:45:6: warning: converting the result of
'<<' to a boolean always evaluates to false
[-Wtautological-constant-compare]
if (PAGE_DEFAULT_KEY)
^
../arch/s390/include/asm/page.h:23:44: note: expanded from macro
'PAGE_DEFAULT_KEY'
#define PAGE_DEFAULT_KEY (PAGE_DEFAULT_ACC << 4)
^
1 warning generated.
Explicitly compare this against zero to silence the warning as it is
intended to be used in a boolean context.
Fixes: de3fa841e429 ("s390/mm: fix compile for PAGE_DEFAULT_KEY != 0")
Link: https://github.com/ClangBuiltLinux/linux/issues/860
Link: https://lkml.kernel.org/r/20200214064207.10381-1-natechancellor@gmail.com
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 45f7a0da600d3c409b5ad8d5ddddacd98ddc8840 ]
Currently backtrace from ftraced function does not contain ftraced
function itself. e.g. for "path_openat":
arch_stack_walk+0x15c/0x2d8
stack_trace_save+0x50/0x68
stack_trace_call+0x15e/0x3d8
ftrace_graph_caller+0x0/0x1c <-- ftrace code
do_filp_open+0x7c/0xe8 <-- ftraced function caller
do_open_execat+0x76/0x1b8
open_exec+0x52/0x78
load_elf_binary+0x180/0x1160
search_binary_handler+0x8e/0x288
load_script+0x2a8/0x2b8
search_binary_handler+0x8e/0x288
__do_execve_file.isra.39+0x6fa/0xb40
__s390x_sys_execve+0x56/0x68
system_call+0xdc/0x2d8
Ftraced function is expected in the backtrace by ftrace kselftests, which
are now failing. It would also be nice to have it for clarity reasons.
"ftrace_caller" itself is called without stack frame allocated for it
and does not store its caller (ftraced function). Instead it simply
allocates a stack frame for "ftrace_trace_function" and sets backchain
to point to ftraced function stack frame (which contains ftraced function
caller in saved r14).
To fix this issue make "ftrace_caller" allocate a stack frame
for itself just to store ftraced function for the stack unwinder.
As a result backtrace looks like the following:
arch_stack_walk+0x15c/0x2d8
stack_trace_save+0x50/0x68
stack_trace_call+0x15e/0x3d8
ftrace_graph_caller+0x0/0x1c <-- ftrace code
path_openat+0x6/0xd60 <-- ftraced function
do_filp_open+0x7c/0xe8 <-- ftraced function caller
do_open_execat+0x76/0x1b8
open_exec+0x52/0x78
load_elf_binary+0x180/0x1160
search_binary_handler+0x8e/0x288
load_script+0x2a8/0x2b8
search_binary_handler+0x8e/0x288
__do_execve_file.isra.39+0x6fa/0xb40
__s390x_sys_execve+0x56/0x68
system_call+0xdc/0x2d8
Reported-by: Sven Schnelle <sven.schnelle@ibm.com>
Tested-by: Sven Schnelle <sven.schnelle@ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0f8a206df7c920150d2aa45574fba0ab7ff6be4f upstream.
Clang warns:
In file included from ../arch/s390/boot/startup.c:3:
In file included from ../include/linux/elf.h:5:
In file included from ../arch/s390/include/asm/elf.h:132:
In file included from ../include/linux/compat.h:10:
In file included from ../include/linux/time.h:74:
In file included from ../include/linux/time32.h:13:
In file included from ../include/linux/timex.h:65:
../arch/s390/include/asm/timex.h:160:20: warning: passing 'unsigned char
[16]' to parameter of type 'char *' converts between pointers to integer
types with different sign [-Wpointer-sign]
get_tod_clock_ext(clk);
^~~
../arch/s390/include/asm/timex.h:149:44: note: passing argument to
parameter 'clk' here
static inline void get_tod_clock_ext(char *clk)
^
Change clk's type to just be char so that it matches what happens in
get_tod_clock_ext.
Fixes: 57b28f66316d ("[S390] s390_hypfs: Add new attributes")
Link: https://github.com/ClangBuiltLinux/linux/issues/861
Link: http://lkml.kernel.org/r/20200208140858.47970-1-natechancellor@gmail.com
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 72a81ad9d6d62dcb79f7e8ad66ffd1c768b72026 ]
If an SMT capable system is not IPL'ed from the first CPU the setup of
the physical to logical CPU mapping is broken: the IPL core gets CPU
number 0, but then the next core gets CPU number 1. Correct would be
that all SMT threads of CPU 0 get the subsequent logical CPU numbers.
This is important since a lot of code (like e.g. the CPU topology
code) assumes that CPU maps are setup like this. If the mapping is
broken the system will not IPL due to broken topology masks:
[ 1.716341] BUG: arch topology broken
[ 1.716342] the SMT domain not a subset of the MC domain
[ 1.716343] BUG: arch topology broken
[ 1.716344] the MC domain not a subset of the BOOK domain
This scenario can usually not happen since LPARs are always IPL'ed
from CPU 0 and also re-IPL is intiated from CPU 0. However older
kernels did initiate re-IPL on an arbitrary CPU. If therefore a re-IPL
from an old kernel into a new kernel is initiated this may lead to
crash.
Fix this by setting up the physical to logical CPU mapping correctly.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0539ad0b22877225095d8adef0c376f52cc23834 ]
The s390 CPU Measurement sampling facility has an overflow condition
which fires when all entries in a SBD are used.
The measurement alert interrupt is triggered and reads out all samples
in this SDB. It then tests the successor SDB, if this SBD is not full,
the interrupt handler does not read any samples at all from this SDB
The design waits for the hardware to fill this SBD and then trigger
another meassurement alert interrupt.
This scheme works nicely until
an perf_event_overflow() function call discards the sample due to
a too high sampling rate.
The interrupt handler has logic to read out a partially filled SDB
when the perf event overflow condition in linux common code is met.
This causes the CPUM sampling measurement hardware and the PMU
device driver to operate on the same SBD's trailer entry.
This should not happen.
This can be seen here using this trace:
cpumsf_pmu_add: tear:0xb5286000
hw_perf_event_update: sdbt 0xb5286000 full 1 over 0 flush_all:0
hw_perf_event_update: sdbt 0xb5286008 full 0 over 0 flush_all:0
above shows 1. interrupt
hw_perf_event_update: sdbt 0xb5286008 full 1 over 0 flush_all:0
hw_perf_event_update: sdbt 0xb5286008 full 0 over 0 flush_all:0
above shows 2. interrupt
... this goes on fine until...
hw_perf_event_update: sdbt 0xb5286068 full 1 over 0 flush_all:0
perf_push_sample1: overflow
one or more samples read from the IRQ handler are rejected by
perf_event_overflow() and the IRQ handler advances to the next SDB
and modifies the trailer entry of a partially filled SDB.
hw_perf_event_update: sdbt 0xb5286070 full 0 over 0 flush_all:1
timestamp: 14:32:52.519953
Next time the IRQ handler is called for this SDB the trailer entry shows
an overflow count of 19 missed entries.
hw_perf_event_update: sdbt 0xb5286070 full 1 over 19 flush_all:1
timestamp: 14:32:52.970058
Remove access to a follow on SDB when event overflow happened.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 39d4a501a9ef55c57b51e3ef07fc2aeed7f30b3b ]
Function perf_event_ever_overflow() and perf_event_account_interrupt()
are called every time samples are processed by the interrupt handler.
However function perf_event_account_interrupt() has checks to avoid being
flooded with interrupts (more then 1000 samples are received per
task_tick). Samples are then dropped and a PERF_RECORD_THROTTLED is
added to the perf data. The perf subsystem limit calculation is:
maximum sample frequency := 100000 --> 1 samples per 10 us
task_tick = 10ms = 10000us --> 1000 samples per task_tick
The work flow is
measurement_alert() uses SDBT head and each SBDT points to 511
SDB pages, each with 126 sample entries. After processing 8 SBDs
and for each valid sample calling:
perf_event_overflow()
perf_event_account_interrupts()
there is a considerable amount of samples being dropped, especially when
the sample frequency is very high and near the 100000 limit.
To avoid the high amount of samples being dropped near the end of a
task_tick time frame, increment the sampling interval in case of
dropped events. The CPU Measurement sampling facility on the s390
supports only intervals, specifiing how many CPU cycles have to be
executed before a sample is generated. Increase the interval when the
samples being generated hit the task_tick limit.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 247f265fa502e7b17a0cb0cc330e055a36aafce4 ]
Each SBDT is located at a 4KB page and contains 512 entries.
Each entry of a SDBT points to a SDB, a 4KB page containing
sampled data. The last entry is a link to another SDBT page.
When an event is created the function sequence executed is:
__hw_perf_event_init()
+--> allocate_buffers()
+--> realloc_sampling_buffers()
+---> alloc_sample_data_block()
Both functions realloc_sampling_buffers() and
alloc_sample_data_block() allocate pages and the allocation
can fail. This is handled correctly and all allocated
pages are freed and error -ENOMEM is returned to the
top calling function. Finally the event is not created.
Once the event has been created, the amount of initially
allocated SDBT and SDB can be too low. This is detected
during measurement interrupt handling, where the amount
of lost samples is calculated. If the number of lost samples
is too high considering sampling frequency and already allocated
SBDs, the number of SDBs is enlarged during the next execution
of cpumsf_pmu_enable().
If more SBDs need to be allocated, functions
realloc_sampling_buffers()
+---> alloc-sample_data_block()
are called to allocate more pages. Page allocation may fail
and the returned error is ignored. A SDBT and SDB setup
already exists.
However the modified SDBTs and SDBs might end up in a situation
where the first entry of an SDBT does not point to an SDB,
but another SDBT, basicly an SBDT without payload.
This can not be handled by the interrupt handler, where an SDBT
must have at least one entry pointing to an SBD.
Add a check to avoid SDBTs with out payload (SDBs) when enlarging
the buffer setup.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 544f1d62e3e6c6e6d17a5e56f6139208acb5ff46 ]
Due to kptr_restrict, JITted BPF code is now displayed like this:
000000000b6ed1b2: ebdff0800024 stmg %r13,%r15,128(%r15)
000000004cde2ba0: 41d0f040 la %r13,64(%r15)
00000000fbad41b0: a7fbffa0 aghi %r15,-96
Leaking kernel addresses to dmesg is not a concern in this case, because
this happens only when JIT debugging is explicitly activated, which only
root can do.
Use %px in this particular instance, and also to print an instruction
address in show_code and PCREL (e.g. brasl) arguments in print_insn.
While at present functionally equivalent to %016lx, %px is recommended
by Documentation/core-api/printk-formats.rst for such cases.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
The mainline commit 8fde12ca79af ("mm: prevent get_user_pages() from
overflowing page refcount") was backported to 4.9.y stable as commit
2ed768cfd895. The backport however missed that in 4.9, there are several
arch-specific gup.c versions with fast gup implementations, so these do not
prevent refcount overflow.
This is partially fixed for x86 in stable-only commit d73af79742e7 ("x86, mm,
gup: prevent get_page() race with munmap in paravirt guest"). This stable-only
commit adds missing parts to x86 version, as well as s390 version, both taken
from the SUSE SLES/openSUSE 4.12-based kernels.
The remaining architectures with own gup.c are sparc, mips, sh. It's unlikely
the known overflow scenario based on FUSE, which needs 140GB of RAM, is a
problem for those architectures, and I don't feel confident enough to patch
them.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 308c3e6673b012beecb96ef04cc65f4a0e7cdd99 ]
Make sure the debug feature and its allocated resources get
released upon unsuccessful architecture initialization.
A related indication of the issue will be reported as kernel
message.
Signed-off-by: Michael Mueller <mimu@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181130143215.69496-2-mimu@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ec0c0bb489727de0d4dca6a00be6970ab8a3b30a ]
Return an error when the function debug_register() fails allocating
the debug handle.
Also remove the registered debug handle when the initialization fails
later on.
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>
[ Upstream commit 348498458505e202df41b6b9a78da448d39298b7 ]
vdso is mapped into user space processes, which won't have kasan
shodow mapped.
Reviewed-by: Martin Schwidefsky <schwidefsky@de.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>
commit 0d9ce162cf46c99628cc5da9510b959c7976735b upstream.
It doesn't seem as if there is any particular need for kvm_lock to be a
spinlock, so convert the lock to a mutex so that sleepable functions (in
particular cond_resched()) can be called while holding it.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 4.9:
- Drop changes in kvm_hyperv_tsc_notifier(), vm_stat_clear(),
vcpu_stat_clear(), kvm_uevent_notify_change()
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b8e51a6a9db94bc1fb18ae831b3dab106b5a4b5f upstream.
The problem is that we were putting the NUL terminator too far:
buf[sizeof(buf) - 1] = '\0';
If the user input isn't NUL terminated and they haven't initialized the
whole buffer then it leads to an info leak. The NUL terminator should
be:
buf[len - 1] = '\0';
Signed-off-by: Yihui Zeng <yzeng56@asu.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[heiko.carstens@de.ibm.com: keep semantics of how *lenp and *ppos are handled]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 062795fcdcb2d22822fb42644b1d76a8ad8439b3 ]
Depending on inlining decisions by the compiler, __get/put_user_fn
might become out of line. Then the compiler is no longer able to tell
that size can only be 1,2,4 or 8 due to the check in __get/put_user
resulting in false positives like
./arch/s390/include/asm/uaccess.h: In function ‘__put_user_fn’:
./arch/s390/include/asm/uaccess.h:113:9: warning: ‘rc’ may be used uninitialized in this function [-Wmaybe-uninitialized]
113 | return rc;
| ^~
./arch/s390/include/asm/uaccess.h: In function ‘__get_user_fn’:
./arch/s390/include/asm/uaccess.h:143:9: warning: ‘rc’ may be used uninitialized in this function [-Wmaybe-uninitialized]
143 | return rc;
| ^~
These functions are supposed to be always inlined. Mark it as such.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f3122a79a1b0a113d3aea748e0ec26f2cb2889de upstream.
arch_update_cpu_topology is first called from:
kernel_init_freeable->sched_init_smp->sched_init_domains
even before cpus has been registered in:
kernel_init_freeable->do_one_initcall->s390_smp_init
Do not trigger kobject_uevent change events until cpu devices are
actually created. Fixes the following kasan findings:
BUG: KASAN: global-out-of-bounds in kobject_uevent_env+0xb40/0xee0
Read of size 8 at addr 0000000000000020 by task swapper/0/1
BUG: KASAN: global-out-of-bounds in kobject_uevent_env+0xb36/0xee0
Read of size 8 at addr 0000000000000018 by task swapper/0/1
CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B
Hardware name: IBM 3906 M04 704 (LPAR)
Call Trace:
([<0000000143c6db7e>] show_stack+0x14e/0x1a8)
[<0000000145956498>] dump_stack+0x1d0/0x218
[<000000014429fb4c>] print_address_description+0x64/0x380
[<000000014429f630>] __kasan_report+0x138/0x168
[<0000000145960b96>] kobject_uevent_env+0xb36/0xee0
[<0000000143c7c47c>] arch_update_cpu_topology+0x104/0x108
[<0000000143df9e22>] sched_init_domains+0x62/0xe8
[<000000014644c94a>] sched_init_smp+0x3a/0xc0
[<0000000146433a20>] kernel_init_freeable+0x558/0x958
[<000000014599002a>] kernel_init+0x22/0x160
[<00000001459a71d4>] ret_from_fork+0x28/0x30
[<00000001459a71dc>] kernel_thread_starter+0x0/0x10
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a13b03bbb4575b350b46090af4dfd30e735aaed1 upstream.
If the KVM_S390_MEM_OP ioctl is called with an access register >= 16,
then there is certainly a bug in the calling userspace application.
We check for wrong access registers, but only if the vCPU was already
in the access register mode before (i.e. the SIE block has recorded
it). The check is also buried somewhere deep in the calling chain (in
the function ar_translation()), so this is somewhat hard to find.
It's better to always report an error to the userspace in case this
field is set wrong, and it's safer in the KVM code if we block wrong
values here early instead of relying on a check somewhere deep down
the calling chain, so let's add another check to kvm_s390_guest_mem_op()
directly.
We also should check that the "size" is non-zero here (thanks to Janosch
Frank for the hint!). If we do not check the size, we could call vmalloc()
with this 0 value, and this will cause a kernel warning.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Link: https://lkml.kernel.org/r/20190829122517.31042-1-thuth@redhat.com
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b54c64f7adeb241423cd46598f458b5486b0375e ]
In hypfs_fill_super(), if hypfs_create_update_file() fails,
sbi->update_file is left holding an error number. This is passed to
hypfs_kill_super() which doesn't check for this.
Fix this by not setting sbi->update_value until after we've checked for
error.
Fixes: 24bbb1faf3f0 ("[PATCH] s390_hypfs filesystem")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
cc: Heiko Carstens <heiko.carstens@de.ibm.com>
cc: linux-s390@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9e323d45ba94262620a073a3f9945ca927c07c71 ]
With 'extra run-time crypto self tests' enabled, the selftest
for s390-xts fails with
alg: skcipher: xts-aes-s390 encryption unexpectedly succeeded on
test vector "random: len=0 klen=64"; expected_error=-22,
cfg="random: inplace use_digest nosimd src_divs=[2.61%@+4006,
84.44%@+21, 1.55%@+13, 4.50%@+344, 4.26%@+21, 2.64%@+27]"
This special case with nbytes=0 is not handled correctly and this
fix now makes sure that -EINVAL is returned when there is en/decrypt
called with 0 bytes to en/decrypt.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 91b4db5313a2c793aabc2143efb8ed0cf0fdd097 ]
"p runtime/jit: pass > 32bit index to tail_call" fails when
bpf_jit_enable=1, because the tail call is not executed.
This in turn is because the generated code assumes index is 64-bit,
while it must be 32-bit, and as a result prog array bounds check fails,
while it should pass. Even if bounds check would have passed, the code
that follows uses 64-bit index to compute prog array offset.
Fix by using clrj instead of clgrj for comparing index with array size,
and also by using llgfr for truncating index to 32 bits before using it
to compute prog array offset.
Fixes: 6651ee070b31 ("s390/bpf: implement bpf_tail_call() helper")
Reported-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bb2d267c448f4bc3a3389d97c56391cb779178ae ]
"masking, test in bounds 3" fails on s390, because
BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0) ignores the top 32 bits of
BPF_REG_2. The reason is that JIT emits lcgfr instead of lcgr.
The associated comment indicates that the code was intended to
emit lcgr in the first place, it's just that the wrong opcode
was used.
Fix by using the correct opcode.
Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 53936b5bf35e140ae27e4bbf0447a61063f400da upstream.
When the userspace program runs the KVM_S390_INTERRUPT ioctl to inject
an interrupt, we convert them from the legacy struct kvm_s390_interrupt
to the new struct kvm_s390_irq via the s390int_to_s390irq() function.
However, this function does not take care of all types of interrupts
that we can inject into the guest later (see do_inject_vcpu()). Since we
do not clear out the s390irq values before calling s390int_to_s390irq(),
there is a chance that we copy random data from the kernel stack which
could be leaked to the userspace later.
Specifically, the problem exists with the KVM_S390_INT_PFAULT_INIT
interrupt: s390int_to_s390irq() does not handle it, and the function
__inject_pfault_init() later copies irq->u.ext which contains the
random kernel stack data. This data can then be leaked either to
the guest memory in __deliver_pfault_init(), or the userspace might
retrieve it directly with the KVM_S390_GET_IRQ_STATE ioctl.
Fix it by handling that interrupt type in s390int_to_s390irq(), too,
and by making sure that the s390irq struct is properly pre-initialized.
And while we're at it, make sure that s390int_to_s390irq() now
directly returns -EINVAL for unknown interrupt types, so that we
immediately get a proper error code in case we add more interrupt
types to do_inject_vcpu() without updating s390int_to_s390irq()
sometime in the future.
Cc: stable@vger.kernel.org
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/kvm/20190912115438.25761-1-thuth@redhat.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fa9dd599b4dae841924b022768354cfde9affecb upstream.
Having a pure_initcall() callback just to permanently enable BPF
JITs under CONFIG_BPF_JIT_ALWAYS_ON is unnecessary and could leave
a small race window in future where JIT is still disabled on boot.
Since we know about the setting at compilation time anyway, just
initialize it properly there. Also consolidate all the individual
bpf_jit_enable variables into a single one and move them under one
location. Moreover, don't allow for setting unspecified garbage
values on them.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
[bwh: Backported to 4.9 as dependency of commit 2e4a30983b0f
"bpf: restrict access to core bpf sysctls":
- Drop change in arch/mips/net/ebpf_jit.c
- Drop change to bpf_jit_kallsyms
- Adjust filenames, context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4f18d869ffd056c7858f3d617c71345cf19be008 upstream.
The stfle inline assembly returns the number of double words written
(condition code 0) or the double words it would have written
(condition code 3), if the memory array it got as parameter would have
been large enough.
The current stfle implementation assumes that the array is always
large enough and clears those parts of the array that have not been
written to with a subsequent memset call.
If however the array is not large enough memset will get a negative
length parameter, which means that memset clears memory until it gets
an exception and the kernel crashes.
To fix this simply limit the maximum length. Move also the inline
assembly to an extra function to avoid clobbering of register 0, which
might happen because of the added min_t invocation together with code
instrumentation.
The bug was introduced with commit 14375bc4eb8d ("[S390] cleanup
facility list handling") but was rather harmless, since it would only
write to a rather large array. It became a potential problem with
commit 3ab121ab1866 ("[S390] kernel: Add z/VM LGR detection"). Since
then it writes to an array with only four double words, while some
machines already deliver three double words. As soon as machines have
a facility bit within the fifth double a crash on IPL would happen.
Fixes: 14375bc4eb8d ("[S390] cleanup facility list handling")
Cc: <stable@vger.kernel.org> # v2.6.37+
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
