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[ Upstream commit d6df52e9996dcc2062c3d9c9123288468bb95b52 ]
To be able to patch kernel code before paging is initialized do plain
memcpy if DAT is off. This is required to enable early jump label
initialization.
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 cb2cceaefb4c4dc28fc27ff1f1b2d258bfc10353 ]
s390_kernel_write()'s function type is almost identical to memcpy().
Change its return type to "void *" so they can be used interchangeably.
Cc: linux-s390@vger.kernel.org
Cc: heiko.carstens@de.ibm.com
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> # s390
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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>
commit 95e61b1b5d6394b53d147c0fcbe2ae70fbe09446 upstream.
Command line parameters might set static keys. This is true for s390 at
least since commit 6471384af2a6 ("mm: security: introduce init_on_alloc=1
and init_on_free=1 boot options"). To avoid the following WARN:
static_key_enable_cpuslocked(): static key 'init_on_alloc+0x0/0x40' used
before call to jump_label_init()
call jump_label_init() just before parse_early_param().
jump_label_init() is safe to call multiple times (x86 does that), doesn't
do any memory allocations and hence should be safe to call that early.
Fixes: 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options")
Cc: <stable@vger.kernel.org> # 5.3: d6df52e9996d: s390/maccess: add no DAT mode to kernel_write
Cc: <stable@vger.kernel.org> # 5.3
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: 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 827c4913923e0b441ba07ba4cc41e01181102303 ]
When specifying insanely large debug buffers a kernel warning is
printed. The debug code does handle the error gracefully, though.
Instead of duplicating the check let us silence the warning to
avoid crashes when panic_on_warn is used.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 478237a595120a18e9b52fd2c57a6e8b7a01e411 ]
clock_getres in the vDSO library has to preserve the same behaviour
of posix_get_hrtimer_res().
In particular, posix_get_hrtimer_res() does:
sec = 0;
ns = hrtimer_resolution;
and hrtimer_resolution depends on the enablement of the high
resolution timers that can happen either at compile or at run time.
Fix the s390 vdso implementation of clock_getres keeping a copy of
hrtimer_resolution in vdso data and using that directly.
Link: https://lkml.kernel.org/r/20200324121027.21665-1-vincenzo.frascino@arm.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[heiko.carstens@de.ibm.com: use llgf for proper zero extension]
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 2b2a25845d534ac6d55086e35c033961fdd83a26 ]
Currently, the VDSO is being linked through $(CC). This does not match
how the rest of the kernel links objects, which is through the $(LD)
variable.
When clang is built in a default configuration, it first attempts to use
the target triple's default linker, which is just ld. However, the user
can override this through the CLANG_DEFAULT_LINKER cmake define so that
clang uses another linker by default, such as LLVM's own linker, ld.lld.
This can be useful to get more optimized links across various different
projects.
However, this is problematic for the s390 vDSO because ld.lld does not
have any s390 emulatiom support:
https://github.com/llvm/llvm-project/blob/llvmorg-10.0.1-rc1/lld/ELF/Driver.cpp#L132-L150
Thus, if a user is using a toolchain with ld.lld as the default, they
will see an error, even if they have specified ld.bfd through the LD
make variable:
$ make -j"$(nproc)" -s ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- LLVM=1 \
LD=s390x-linux-gnu-ld \
defconfig arch/s390/kernel/vdso64/
ld.lld: error: unknown emulation: elf64_s390
clang-11: error: linker command failed with exit code 1 (use -v to see invocation)
Normally, '-fuse-ld=bfd' could be used to get around this; however, this
can be fragile, depending on paths and variable naming. The cleaner
solution for the kernel is to take advantage of the fact that $(LD) can
be invoked directly, which bypasses the heuristics of $(CC) and respects
the user's choice. Similar changes have been done for ARM, ARM64, and
MIPS.
Link: https://lkml.kernel.org/r/20200602192523.32758-1-natechancellor@gmail.com
Link: https://github.com/ClangBuiltLinux/linux/issues/1041
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
[heiko.carstens@de.ibm.com: add --build-id flag]
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 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>
[ Upstream commit 00332c16b1604242a56289ff2b26e283dbad0812 ]
tracing expects to see invalid syscalls, so pass it through.
The syscall path in entry.S checks the syscall number before
looking up the handler, so it is still safe.
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 e1750a3d9abbea2ece29cac8dc5a6f5bc19c1492 ]
After disabling a function, the original handle is logged instead of
the disabled handle.
Link: https://lkml.kernel.org/r/20200522183922.5253-1-ptesarik@suse.com
Fixes: 17cdec960cf7 ("s390/pci: Recover handle in clp_set_pci_fn()")
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Petr Tesarik <ptesarik@suse.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ac8372f3b4e41015549b331a4f350224661e7fc6 ]
On s390, the layout of normal and large ptes (i.e. pmds/puds) differs.
Therefore, set_huge_pte_at() does a conversion from a normal pte to
the corresponding large pmd/pud. So, when converting an empty pte, this
should result in an empty pmd/pud, which would return true for
pmd/pud_none().
However, after conversion we also mark the pmd/pud as large, and
therefore present. For empty ptes, this will result in an empty pmd/pud
that is also marked as large, and pmd/pud_none() would not return true.
There is currently no issue with this behaviour, as set_huge_pte_at()
does not seem to be called for empty ptes. It would be valid though, so
let's fix this by not marking empty ptes as large in set_huge_pte_at().
This was found by testing a patch from from Anshuman Khandual, which is
currently discussed on LKML ("mm/debug: Add more arch page table helper
tests").
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.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>
commit 70b690547d5ea1a3d135a4cc39cd1e08246d0c3a upstream.
initrd_start must not point at the location the initrd is loaded into
the crashkernel memory but at the location it will be after the
crashkernel memory is swapped with the memory at 0.
Fixes: ee337f5469fd ("s390/kexec_file: Add crash support to image loader")
Reported-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Tested-by: Lianbo Jiang <lijiang@redhat.com>
Link: https://lore.kernel.org/r/20200512193956.15ae3f23@laptop2-ibm.local
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4c1cbcbd6c56c79de2c07159be4f55386bb0bef2 upstream.
With certain kernel configurations, the R_390_JMP_SLOT relocation type
might be generated, which is not expected by the KASLR relocation code,
and the kernel stops with the message "Unknown relocation type".
This was found with a zfcpdump kernel config, where CONFIG_MODULES=n
and CONFIG_VFIO=n. In that case, symbol_get() is used on undefined
__weak symbols in virt/kvm/vfio.c, which results in the generation
of R_390_JMP_SLOT relocation types.
Fix this by handling R_390_JMP_SLOT similar to R_390_GLOB_DAT.
Fixes: 805bc0bc238f ("s390/kernel: build a relocatable kernel")
Cc: <stable@vger.kernel.org> # v5.2+
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f058599e22d59e594e5aae1dc10560568d8f4a8b upstream.
The s390_mmio_read/write syscalls are currently broken when running with
MIO.
The new pcistb_mio/pcstg_mio/pcilg_mio instructions are executed
similiarly to normal load/store instructions and do address translation
in the current address space. That means inside the kernel they are
aware of mappings into kernel address space while outside the kernel
they use user space mappings (usually created through mmap'ing a PCI
device file).
Now when existing user space applications use the s390_pci_mmio_write
and s390_pci_mmio_read syscalls, they pass I/O addresses that are mapped
into user space so as to be usable with the new instructions without
needing a syscall. Accessing these addresses with the old instructions
as done currently leads to a kernel panic.
Also, for such a user space mapping there may not exist an equivalent
kernel space mapping which means we can't just use the new instructions
in kernel space.
Instead of replicating user mappings in the kernel which then might
collide with other mappings, we can conceptually execute the new
instructions as if executed by the user space application using the
secondary address space. This even allows us to directly store to the
user pointer without the need for copy_to/from_user().
Cc: stable@vger.kernel.org
Fixes: 71ba41c9b1d9 ("s390/pci: provide support for MIO instructions")
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5615e74f48dcc982655543e979b6c3f3f877e6f6 upstream.
In LPAR we will only get an intercept for FC==3 for the PQAP
instruction. Running nested under z/VM can result in other intercepts as
well as ECA_APIE is an effective bit: If one hypervisor layer has
turned this bit off, the end result will be that we will get intercepts for
all function codes. Usually the first one will be a query like PQAP(QCI).
So the WARN_ON_ONCE is not right. Let us simply remove it.
Cc: Pierre Morel <pmorel@linux.ibm.com>
Cc: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: stable@vger.kernel.org # v5.3+
Fixes: e5282de93105 ("s390: ap: kvm: add PQAP interception for AQIC")
Link: https://lore.kernel.org/kvm/20200505083515.2720-1-borntraeger@de.ibm.com
Reported-by: Qian Cai <cailca@icloud.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 86dbf32da150339ca81509fa2eb84c814b55258b upstream.
with the introduction of CPU directed interrupts the kernel
parameter pci=force_floating was introduced to fall back
to the previous behavior using floating irqs.
However we were still setting the affinity in that case,
both in __irq_alloc_descs() and via the irq_set_affinity
callback in struct irq_chip.
For the former only set the affinity in the directed case.
The latter is explicitly set in zpci_directed_irq_init()
so we can just leave it unset for the floating case.
Fixes: e979ce7bced2 ("s390/pci: provide support for CPU directed interrupts")
Co-developed-by: Alexander Schmidt <alexs@linux.ibm.com>
Signed-off-by: Alexander Schmidt <alexs@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8ebf6da9db1b2a20bb86cc1bee2552e894d03308 upstream.
Switching tracers include instruction patching. To prevent that a
instruction is patched while it's read the instruction patching is done
in stop_machine 'context'. This also means that any function called
during stop_machine must not be traced. Thus add 'notrace' to all
functions called within stop_machine.
Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls")
Fixes: 38f2c691a4b3 ("s390: improve wait logic of stop_machine")
Fixes: 4ecf0a43e729 ("processor: get rid of cpu_relax_yield")
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 316ec154810960052d4586b634156c54d0778f74 upstream.
A page table upgrade in a kernel section that uses secondary address
mode will mess up the kernel instructions as follows:
Consider the following scenario: two threads are sharing memory.
On CPU1 thread 1 does e.g. strnlen_user(). That gets to
old_fs = enable_sacf_uaccess();
len = strnlen_user_srst(src, size);
and
" la %2,0(%1)\n"
" la %3,0(%0,%1)\n"
" slgr %0,%0\n"
" sacf 256\n"
"0: srst %3,%2\n"
in strnlen_user_srst(). At that point we are in secondary space mode,
control register 1 points to kernel page table and instruction fetching
happens via c1, rather than usual c13. Interrupts are not disabled, for
obvious reasons.
On CPU2 thread 2 does MAP_FIXED mmap(), forcing the upgrade of page table
from 3-level to e.g. 4-level one. We'd allocated new top-level table,
set it up and now we hit this:
notify = 1;
spin_unlock_bh(&mm->page_table_lock);
}
if (notify)
on_each_cpu(__crst_table_upgrade, mm, 0);
OK, we need to actually change over to use of new page table and we
need that to happen in all threads that are currently running. Which
happens to include the thread 1. IPI is delivered and we have
static void __crst_table_upgrade(void *arg)
{
struct mm_struct *mm = arg;
if (current->active_mm == mm)
set_user_asce(mm);
__tlb_flush_local();
}
run on CPU1. That does
static inline void set_user_asce(struct mm_struct *mm)
{
S390_lowcore.user_asce = mm->context.asce;
OK, user page table address updated...
__ctl_load(S390_lowcore.user_asce, 1, 1);
... and control register 1 set to it.
clear_cpu_flag(CIF_ASCE_PRIMARY);
}
IPI is run in home space mode, so it's fine - insns are fetched
using c13, which always points to kernel page table. But as soon
as we return from the interrupt, previous PSW is restored, putting
CPU1 back into secondary space mode, at which point we no longer
get the kernel instructions from the kernel mapping.
The fix is to only fixup the control registers that are currently in use
for user processes during the page table update. We must also disable
interrupts in enable_sacf_uaccess to synchronize the cr and
thread.mm_segment updates against the on_each-cpu.
Fixes: 0aaba41b58bc ("s390: remove all code using the access register mode")
Cc: stable@vger.kernel.org # 4.15+
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
References: CVE-2020-11884
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 97daa028f3f621adff2c4f7b15fe0874e5b5bd6c upstream.
Return the index of the last valid slot from gfn_to_memslot_approx() if
its binary search loop yielded an out-of-bounds index. The index can
be out-of-bounds if the specified gfn is less than the base of the
lowest memslot (which is also the last valid memslot).
Note, the sole caller, kvm_s390_get_cmma(), ensures used_slots is
non-zero.
Fixes: afdad61615cc3 ("KVM: s390: Fix storage attributes migration with memory slots")
Cc: stable@vger.kernel.org # 4.19.x: 0774a964ef56: KVM: Fix out of range accesses to memslots
Cc: stable@vger.kernel.org # 4.19.x
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200408064059.8957-3-sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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>
[ Upstream commit 4141b6a5e9f171325effc36a22eb92bf961e7a5c ]
When perf record -e SF_CYCLES_BASIC_DIAG runs with very high
frequency, the samples arrive faster than the perf process can
save them to file. Eventually, for longer running processes, this
leads to the siutation where the trace buffers allocated by perf
slowly fills up. At one point the auxiliary trace buffer is full
and the CPU Measurement sampling facility is turned off. Furthermore
a warning is printed to the kernel log buffer:
cpum_sf: The AUX buffer with 0 pages for the diagnostic-sampling
mode is full
The number of allocated pages for the auxiliary trace buffer is shown
as zero pages. That is wrong.
Fix this by saving the number of allocated pages before entering the
work loop in the interrupt handler. When the interrupt handler processes
the samples, it may detect the buffer full condition and stop sampling,
reducing the buffer size to zero.
Print the correct value in the error message:
cpum_sf: The AUX buffer with 256 pages for the diagnostic-sampling
mode is full
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>
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 0b38b5e1d0e2f361e418e05c179db05bb688bbd6 upstream.
When userspace executes a syscall or gets interrupted,
BEAR contains a kernel address when returning to userspace.
This make it pretty easy to figure out where the kernel is
mapped even with KASLR enabled. To fix this, add lpswe to
lowcore and always execute it there, so userspace sees only
the lowcore address of lpswe. For this we have to extend
both critical_cleanup and the SWITCH_ASYNC macro to also check
for lpswe addresses in lowcore.
Fixes: b2d24b97b2a9 ("s390/kernel: add support for kernel address space layout randomization (KASLR)")
Cc: <stable@vger.kernel.org> # v5.2+
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 582b4e55403e053d8a48ff687a05174da9cc3fb0 upstream.
On s390 there currently is no implementation of pud_write(). That was ok
as long as we had our own implementation of get_user_pages_fast() which
checked for pud protection by testing the bit directly w/o using
pud_write(). The other callers of pud_write() are not reachable on s390.
After commit 1a42010cdc26 ("s390/mm: convert to the generic
get_user_pages_fast code") we use the generic get_user_pages_fast(), which
does call pud_write() in pud_access_permitted() for FOLL_WRITE access on
a large pud. Without an s390 specific pud_write(), the generic version is
called, which contains a BUG() statement to remind us that we don't have a
proper implementation. This results in a kernel panic.
Fix this by providing an implementation of pud_write().
Cc: <stable@vger.kernel.org> # 5.2+
Fixes: 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast code")
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.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 df057c914a9c219ac8b8ed22caf7da2f80c1fe26 upstream.
In the initial MIO support introduced in
commit 71ba41c9b1d9 ("s390/pci: provide support for MIO instructions")
zpci_map_resource() and zpci_setup_resources() default to using the
mio_wb address as the resource's start address. This means users of the
mapping, which includes most drivers, will get write combining on PCI
Stores. This may lead to problems when drivers expect write through
behavior when not using an explicit ioremap_wc().
Cc: stable@vger.kernel.org
Fixes: 71ba41c9b1d9 ("s390/pci: provide support for MIO instructions")
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e9091ffd6a0aaced111b5d6ead5eaab5cd7101bc ]
As the comment says, sl->sbal holds an absolute address. qeth currently
solves this through wild casting, while zfcp doesn't care.
Handle this properly in the code that actually builds the SL.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com> [for qdio]
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 94e90f727f7424d827256023cace829cad6896f4 ]
For the same reason as commit 19514fc665ff ("arm, kbuild: make "make
install" not depend on vmlinux"), the install targets should never
trigger the rebuild of the kernel.
The variable, CONFIGURE, is not set by anyone. Remove it as well.
Link: https://lkml.kernel.org/r/20200216144829.27023-1-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.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>
commit 788d671517b5c81efbed9310ccbadb8cca86a08e upstream.
Clang warns:
../arch/s390/boot/kaslr.c:78:25: warning: passing 'char *' to parameter
of type 'const u8 *' (aka 'const unsigned char *') converts between
pointers to integer
types with different sign [-Wpointer-sign]
(char *) entropy, (char *) entropy,
^~~~~~~~~~~~~~~~
../arch/s390/include/asm/cpacf.h:280:28: note: passing argument to
parameter 'src' here
u8 *dest, const u8 *src, long src_len)
^
2 warnings generated.
Fix the cast to match what else is done in this function.
Fixes: b2d24b97b2a9 ("s390/kernel: add support for kernel address space layout randomization (KASLR)")
Link: https://github.com/ClangBuiltLinux/linux/issues/862
Link: https://lkml.kernel.org/r/20200208141052.48476-1-natechancellor@gmail.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 17cdec960cf776b20b1fb08c622221babe591d51 ]
When we try to recover a PCI function using
echo 1 > /sys/bus/pci/devices/<id>/recover
or manually with
echo 1 > /sys/bus/pci/devices/<id>/remove
echo 0 > /sys/bus/pci/slots/<slot>/power
echo 1 > /sys/bus/pci/slots/<slot>/power
clp_disable_fn() / clp_enable_fn() call clp_set_pci_fn() to first
disable and then reenable the function.
When the function is already in the requested state we may be left with
an invalid function handle.
To get a new valid handle we do a clp_list_pci() call. For this we need
both the function ID and function handle in clp_set_pci_fn() so pass the
zdev and get both.
To simplify things also pull setting the refreshed function handle into
clp_set_pci_fn()
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.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>
[ Upstream commit 253b3c4b2920e07ce9e2b18800b9b65245e2fafa ]
clang 10 introduces -mpacked-stack compiler option implementation. At the
same time currently it does not support a combination of -mpacked-stack
and -mbackchain. This leads to the following build error:
clang: error: unsupported option '-mpacked-stack with -mbackchain' for
target 's390x-ibm-linux'
If/when clang adds support for a combination of -mpacked-stack and
-mbackchain it would also require -msoft-float (like gcc does). According
to Ulrich Weigand "stack slot assigned to the kernel backchain overlaps
the stack slot assigned to the FPR varargs (both are required to be
placed immediately after the saved r15 slot if present)."
Extend -mpacked-stack compiler option support check to include all 3
options -mpacked-stack -mbackchain -msoft-float which must present to
support -mpacked-stack with -mbackchain.
Acked-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>
commit 27dc0700c3be7c681cea03c5230b93d02f623492 upstream.
The query parameter block might contain additional information and can
be extended in the future. If the size of the block does not suffice we
get an error code of rc=0x100. The buffer will contain all information
up to the specified size and the hypervisor/guest simply do not need the
additional information as they do not know about the new data. That
means that we can (and must) accept rc=0x100 as success.
Cc: stable@vger.kernel.org
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Fixes: 5abb9351dfd9 ("s390/uv: introduce guest side ultravisor code")
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 55680890ea78be0df5e1384989f1be835043c084 upstream.
The initial CPU reset clobbers the userspace fpc and the store status
ioctl clobbers the guest acrs + fpr. As these calls are only done via
ioctl (and not via vcpu_run), no CPU context is loaded, so we can (and
must) act directly on the sync regs, not on the thread context.
Cc: stable@kernel.org
Fixes: e1788bb995be ("KVM: s390: handle floating point registers in the run ioctl not in vcpu_put/load")
Fixes: 31d8b8d41a7e ("KVM: s390: handle access registers in the run ioctl not in vcpu_put/load")
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20200131100205.74720-2-frankja@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5f490a520bcb393389a4d44bec90afcb332eb112 upstream.
Commit ee71d16d22bb ("s390/mm: make TASK_SIZE independent from the number
of page table levels") changed the logic of TASK_SIZE and also removed the
arch_mmap_check() implementation for s390. This combination has a subtle
effect on how get_unmapped_area() for hugetlbfs pages works. It is now
possible that a user process establishes a hugetlbfs mapping at an address
above 4 TB, without triggering a dynamic pagetable upgrade from 3 to 4
levels.
This is because hugetlbfs mappings will not use mm->get_unmapped_area, but
rather file->f_op->get_unmapped_area, which currently is the generic
implementation of hugetlb_get_unmapped_area() that does not know about s390
dynamic pagetable upgrades, but with the new definition of TASK_SIZE, it
will now allow mappings above 4 TB.
Subsequent access to such a mapped address above 4 TB will result in a page
fault loop, because the CPU cannot translate such a large address with 3
pagetable levels. The fault handler will try to map in a hugepage at the
address, but due to the folded pagetable logic it will end up with creating
entries in the 3 level pagetable, possibly overwriting existing mappings,
and then it all repeats when the access is retried.
Apart from the page fault loop, this can have various nasty effects, e.g.
kernel panic from one of the BUG_ON() checks in memory management code,
or even data loss if an existing mapping gets overwritten.
Fix this by implementing HAVE_ARCH_HUGETLB_UNMAPPED_AREA support for s390,
providing an s390 version for hugetlb_get_unmapped_area() with pagetable
upgrade support similar to arch_get_unmapped_area(), which will then be
used instead of the generic version.
Fixes: ee71d16d22bb ("s390/mm: make TASK_SIZE independent from the number of page table levels")
Cc: <stable@vger.kernel.org> # 4.12+
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 40260b01d029ba374637838213af500e03305326 upstream.
The new machine loader on z15 always creates an IPL Report block and
thus sets the IPL_PL_FLAG_IPLSR even when secure boot is disabled. This
causes the wrong message being printed at boot. Fix this by checking for
IPL_PL_FLAG_SIPL instead.
Fixes: 9641b8cc733f ("s390/ipl: read IPL report at early boot")
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c23587c92f6e3260fe3b82bb75b38aa2553b9468 ]
the purgatory must not rely on functions from the "old" kernel,
so we must disable kasan and friends. We also need to have a
separate copy of string.c as the default does not build memcmp
with KASAN.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.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>
[ 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>
commit feee6b2989165631b17ac6d4ccdbf6759254e85a upstream.
We currently try to shrink a single zone when removing memory. We use
the zone of the first page of the memory we are removing. If that
memmap was never initialized (e.g., memory was never onlined), we will
read garbage and can trigger kernel BUGs (due to a stale pointer):
BUG: unable to handle page fault for address: 000000000000353d
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: 0002 [#1] SMP PTI
CPU: 1 PID: 7 Comm: kworker/u8:0 Not tainted 5.3.0-rc5-next-20190820+ #317
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.4
Workqueue: kacpi_hotplug acpi_hotplug_work_fn
RIP: 0010:clear_zone_contiguous+0x5/0x10
Code: 48 89 c6 48 89 c3 e8 2a fe ff ff 48 85 c0 75 cf 5b 5d c3 c6 85 fd 05 00 00 01 5b 5d c3 0f 1f 840
RSP: 0018:ffffad2400043c98 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000200000000 RCX: 0000000000000000
RDX: 0000000000200000 RSI: 0000000000140000 RDI: 0000000000002f40
RBP: 0000000140000000 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000140000
R13: 0000000000140000 R14: 0000000000002f40 R15: ffff9e3e7aff3680
FS: 0000000000000000(0000) GS:ffff9e3e7bb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000353d CR3: 0000000058610000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__remove_pages+0x4b/0x640
arch_remove_memory+0x63/0x8d
try_remove_memory+0xdb/0x130
__remove_memory+0xa/0x11
acpi_memory_device_remove+0x70/0x100
acpi_bus_trim+0x55/0x90
acpi_device_hotplug+0x227/0x3a0
acpi_hotplug_work_fn+0x1a/0x30
process_one_work+0x221/0x550
worker_thread+0x50/0x3b0
kthread+0x105/0x140
ret_from_fork+0x3a/0x50
Modules linked in:
CR2: 000000000000353d
Instead, shrink the zones when offlining memory or when onlining failed.
Introduce and use remove_pfn_range_from_zone(() for that. We now
properly shrink the zones, even if we have DIMMs whereby
- Some memory blocks fall into no zone (never onlined)
- Some memory blocks fall into multiple zones (offlined+re-onlined)
- Multiple memory blocks that fall into different zones
Drop the zone parameter (with a potential dubious value) from
__remove_pages() and __remove_section().
Link: http://lkml.kernel.org/r/20191006085646.5768-6-david@redhat.com
Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e86b319]
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: <stable@vger.kernel.org> [5.0+]
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>
[ 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>
