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The __kretprobe_trampoline_handler() callback, called from low level
arch kprobes methods, has the 'trampoline_address' parameter, which is
entirely superfluous as it basically just replicates:
dereference_kernel_function_descriptor(kretprobe_trampoline)
In fact we had bugs in arch code where it wasn't replicated correctly.
So remove this superfluous parameter and use kretprobe_trampoline_addr()
instead.
Link: https://lkml.kernel.org/r/163163044546.489837.13505751885476015002.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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This clean up the error/notification messages in kprobes related code.
Basically this defines 'pr_fmt()' macros for each files and update
the messages which describes
- what happened,
- what is the kernel going to do or not do,
- is the kernel fine,
- what can the user do about it.
Also, if the message is not needed (e.g. the function returns unique
error code, or other error message is already shown.) remove it,
and replace the message with WARN_*() macros if suitable.
Link: https://lkml.kernel.org/r/163163036568.489837.14085396178727185469.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull more s390 updates from Heiko Carstens:
"Except for the xpram device driver removal it is all about fixes and
cleanups.
- Fix topology update on cpu hotplug, so notifiers see expected
masks. This bug was uncovered with SCHED_CORE support.
- Fix stack unwinding so that the correct number of entries are
omitted like expected by common code. This fixes KCSAN selftests.
- Add kmemleak annotation to stack_alloc to avoid false positive
kmemleak warnings.
- Avoid layering violation in common I/O code and don't unregister
subchannel from child-drivers.
- Remove xpram device driver for which no real use case exists since
the kernel is 64 bit only. Also all hypervisors got required
support removed in the meantime, which means the xpram device
driver is dead code.
- Fix -ENODEV handling of clp_get_state in our PCI code.
- Enable KFENCE in debug defconfig.
- Cleanup hugetlbfs s390 specific Kconfig dependency.
- Quite a lot of trivial fixes to get rid of "W=1" warnings, and and
other simple cleanups"
* tag 's390-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
hugetlbfs: s390 is always 64bit
s390/ftrace: remove incorrect __va usage
s390/zcrypt: remove incorrect kernel doc indicators
scsi: zfcp: fix kernel doc comments
s390/sclp: add __nonstring annotation
s390/hmcdrv_ftp: fix kernel doc comment
s390: remove xpram device driver
s390/pci: read clp_list_pci_req only once
s390/pci: fix clp_get_state() handling of -ENODEV
s390/cio: fix kernel doc comment
s390/ctrlchar: fix kernel doc comment
s390/con3270: use proper type for tasklet function
s390/cpum_cf: move array from header to C file
s390/mm: fix kernel doc comments
s390/topology: fix topology information when calling cpu hotplug notifiers
s390/unwind: use current_frame_address() to unwind current task
s390/configs: enable CONFIG_KFENCE in debug_defconfig
s390/entry: make oklabel within CHKSTG macro local
s390: add kmemleak annotation in stack_alloc()
s390/cio: dont unregister subchannel from child-drivers
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These are all handled correctly when calling the native system call entry
point, so remove the special cases.
Link: https://lkml.kernel.org/r/20210727144859.4150043-6-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The address of ftrace_graph_caller is already virtual.
Using __va() to translate the address is wrong.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Move array from header to C file to avoid that it gets defined in
every C file where the header is included:
In file included from arch/s390/kernel/perf_cpum_cf_common.c:19:
./arch/s390/include/asm/cpu_mcf.h:27:18: warning: ‘cpumf_ctr_ctl’ defined but not used [-Wunused-const-variable=]
27 | static const u64 cpumf_ctr_ctl[CPUMF_CTR_SET_MAX] = {
| ^~~~~~~~~~~~~
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The cpu hotplug notifiers are called without updating the core/thread
masks when a new CPU is added. This causes problems with code setting
up data structures in a cpu hotplug notifier, and relying on that later
in normal code.
This caused a crash in the new core scheduling code (SCHED_CORE),
where rq->core was set up in a notifier depending on cpu masks.
To fix this, add a cpu_setup_mask which is used in update_cpu_masks()
instead of the cpu_online_mask to determine whether the cpu masks should
be set for a certain cpu. Also move update_cpu_masks() to update the
masks before calling notify_cpu_starting() so that the notifiers are
seeing the updated masks.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Cc: <stable@vger.kernel.org>
[hca@linux.ibm.com: get rid of cpu_online_mask handling]
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Merge misc updates from Andrew Morton:
"173 patches.
Subsystems affected by this series: ia64, ocfs2, block, and mm (debug,
pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure,
hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock,
oom-kill, migration, ksm, percpu, vmstat, and madvise)"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits)
mm/madvise: add MADV_WILLNEED to process_madvise()
mm/vmstat: remove unneeded return value
mm/vmstat: simplify the array size calculation
mm/vmstat: correct some wrong comments
mm/percpu,c: remove obsolete comments of pcpu_chunk_populated()
selftests: vm: add COW time test for KSM pages
selftests: vm: add KSM merging time test
mm: KSM: fix data type
selftests: vm: add KSM merging across nodes test
selftests: vm: add KSM zero page merging test
selftests: vm: add KSM unmerge test
selftests: vm: add KSM merge test
mm/migrate: correct kernel-doc notation
mm: wire up syscall process_mrelease
mm: introduce process_mrelease system call
memblock: make memblock_find_in_range method private
mm/mempolicy.c: use in_task() in mempolicy_slab_node()
mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies
mm/mempolicy: advertise new MPOL_PREFERRED_MANY
mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY
...
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Split off from prev patch in the series that implements the syscall.
Link: https://lkml.kernel.org/r/20210809185259.405936-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jan Engelhardt <jengelh@inai.de>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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There are a lot of uses of memblock_find_in_range() along with
memblock_reserve() from the times memblock allocation APIs did not exist.
memblock_find_in_range() is the very core of memblock allocations, so any
future changes to its internal behaviour would mandate updates of all the
users outside memblock.
Replace the calls to memblock_find_in_range() with an equivalent calls to
memblock_phys_alloc() and memblock_phys_alloc_range() and make
memblock_find_in_range() private method of memblock.
This simplifies the callers, ensures that (unlikely) errors in
memblock_reserve() are handled and improves maintainability of
memblock_find_in_range().
Link: https://lkml.kernel.org/r/20210816122622.30279-1-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Acked-by: Kirill A. Shutemov <kirill.shtuemov@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [ACPI]
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Nick Kossifidis <mick@ics.forth.gr> [riscv]
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull exit cleanups from Eric Biederman:
"In preparation of doing something about PTRACE_EVENT_EXIT I have
started cleaning up various pieces of code related to do_exit. Most of
that code I did not manage to get tested and reviewed before the merge
window opened but a handful of very useful cleanups are ready to be
merged.
The first change is simply the removal of the bdflush system call. The
code has now been disabled long enough that even the oldest userspace
working userspace setups anyone can find to test are fine with the
bdflush system call being removed.
Changing m68k fsp040_die to use force_sigsegv(SIGSEGV) instead of
calling do_exit directly is interesting only in that it is nearly the
most difficult of the incorrect uses of do_exit to remove.
The change to the seccomp code to simply send a signal instead of
calling do_coredump directly is a very nice little cleanup made
possible by realizing the existing signal sending helpers were missing
a little bit of functionality that is easy to provide"
* 'exit-cleanups-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
signal/seccomp: Dump core when there is only one live thread
signal/seccomp: Refactor seccomp signal and coredump generation
signal/m68k: Use force_sigsegv(SIGSEGV) in fpsp040_die
exit/bdflush: Remove the deprecated bdflush system call
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Make the oklabel within the CHKSTG macro local. This makes sure that
tools like objdump and the crash debugging tool still disassemble full
functions where the macro has been used instead of stopping half way
where such a global label is used and one has to guess how to
disassemble the rest of such a function:
E.g.:
0000000000cb0270 <mcck_int_handler>:
cb0270: b2 05 03 20 stck 800
...
cb0354: a7 74 00 97 jne cb0482 <oklabel270+0xe2>
0000000000cb0358 <oklabel243>:
cb0358: c0 e0 00 22 4e 8f larl %r14,10fa076 <opcode+0x2558>
...
Fixes: d35925b34996 ("s390/mcck: move storage error checks to assembler")
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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kmemleak with enabled auto scanning reports that our stack allocation is
lost. This is because we're saving the pointer + STACK_INIT_OFFSET to
lowcore. When kmemleak now scans the objects, it thinks that this one is
lost because it can't find a corresponding pointer.
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Heiko Carstens:
- Improve ftrace code patching so that stop_machine is not required
anymore. This requires a small common code patch acked by Steven
Rostedt:
https://lore.kernel.org/linux-s390/20210730220741.4da6fdf6@oasis.local.home/
- Enable KCSAN for s390. This comes with a small common code change to
fix a compile warning. Acked by Marco Elver:
https://lore.kernel.org/r/20210729142811.1309391-1-hca@linux.ibm.com
- Add KFENCE support for s390. This also comes with a minimal x86 patch
from Marco Elver who said also this can be carried via the s390 tree:
https://lore.kernel.org/linux-s390/YQJdarx6XSUQ1tFZ@elver.google.com/
- More changes to prepare the decompressor for relocation.
- Enable DAT also for CPU restart path.
- Final set of register asm removal patches; leaving only three
locations where needed and sane.
- Add NNPA, Vector-Packed-Decimal-Enhancement Facility 2, PCI MIO
support to hwcaps flags.
- Cleanup hwcaps implementation.
- Add new instructions to in-kernel disassembler.
- Various QDIO cleanups.
- Add SCLP debug feature.
- Various other cleanups and improvements all over the place.
* tag 's390-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (105 commits)
s390: remove SCHED_CORE from defconfigs
s390/smp: do not use nodat_stack for secondary CPU start
s390/smp: enable DAT before CPU restart callback is called
s390: update defconfigs
s390/ap: fix state machine hang after failure to enable irq
KVM: s390: generate kvm hypercall functions
s390/sclp: add tracing of SCLP interactions
s390/debug: add early tracing support
s390/debug: fix debug area life cycle
s390/debug: keep debug data on resize
s390/diag: make restart_part2 a local label
s390/mm,pageattr: fix walk_pte_level() early exit
s390: fix typo in linker script
s390: remove do_signal() prototype and do_notify_resume() function
s390/crypto: fix all kernel-doc warnings in vfio_ap_ops.c
s390/pci: improve DMA translation init and exit
s390/pci: simplify CLP List PCI handling
s390/pci: handle FH state mismatch only on disable
s390/pci: fix misleading rc in clp_set_pci_fn()
s390/boot: factor out offset_vmlinux_info() function
...
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The secondary CPU start C routine uses nodat_stack as a
interim stack before finally switching to kernel_stack.
Such scheme is superfluous, since the assembler restart
interrupt handler (that secondary CPU starter is called
from) does not need to use any stack for switching into
DAT mode. Once DAT is on, any stack including virtually-
mapped one could be used.
Avoid the use of nodat_stack and smp_start_secondary()
helper. Instead, initiate kernel_stack directly from
the restart interrupt handler.
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The restart interrupt is triggered whenever a secondary CPU is
brought online, a remote function call dispatched from another
CPU or a manual PSW restart is initiated and causes the system
to kdump. The handling routine is always called with DAT turned
off. It then initializes the stack frame and invokes a callback.
The existing callbacks handle DAT as follows:
* __do_restart() and __machine_kexec() turn in on upon entry;
* __ipl_run(), __reipl_run() and __dump_run() do not turn it
right away, but all of them call diag308() - which turns DAT
on, but only if kasan is enabled;
In addition to the described complexity all callbacks (and the
functions they call) should avoid kasan instrumentation while
DAT is off.
This update enables DAT in the assembler restart handler and
relieves any callbacks (which are mostly C functions) from
dealing with DAT altogether.
There are four types of CPU restart that initialize control
registers in different ways:
1. Start of secondary CPU on boot - control registers are
inherited from the IPL CPU;
2. Restart of online CPU - control registers of the CPU being
restarted are kept;
3. Hotplug of offline CPU - control registers are inherited
from the starting CPU;
4. Start of offline CPU triggered by manual PSW restart -
the control registers are read from the absolute lowcore
and contain the boot time IPL CPU values updated with all
follow-up calls of smp_ctl_set_bit() and smp_ctl_clear_bit()
routines;
In first three cases contents of the control registers is the
most recent. In the latter case control registers are good
enough to facilitate successful completion of kdump operation.
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Add tracing of interactions between the SCLP base driver, firmware and
other drivers to support problem determination in case of SCLP-related
issues.
For that purpose this patch introduces two new s390dbf debug areas:
- sclp: An abbreviated log of all common interactions
- sclp_err: A full log of failed or abnormal interactions
Tracing of full SCCB contents can be enabled for the sclp area by
setting its debug level to maximum (6).
Overview of added trace events:
* Firmware interaction:
- SRV1: Service call about to be issued
- SRV2: Service call was issued
- INT: Interrupt received
* Driver interaction:
- RQAD: Request was added
- RQOK: Request success
- RQAB: Request aborted
- RQTM: Request timed out
- REG: Event listener registered
- UREG: Event listener unregistered
- EVNT: Event callback
- STCG: State-change callback
* Abnormal events:
- TMO: A timeout occurred
- UNEX: Unexpected SCCB completion
* Other (not traced at default level):
- SYN1: Synchronous wait start
- SYN2: Synchronous wait end
Since the SCLP interface is used by console drivers this patch also
moves s390dbf printks outside the critical section protected by debug
area locks to prevent a potential deadlock that would otherwise be
introduced between console_owner --> sclp_lock --> sclp_debug.lock.
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Debug areas can currently only be used after s390dbf initialization
which occurs as a postcore_initcall. This is too late for tracing
earlier code such as that related to console_init().
This patch introduces a macro for defining a statically initialized
debug area that can be used to trace very early code. The macro is made
available for built-in code only because modules are never running
during early boot.
Example usage:
1. Define static debug area:
DEFINE_STATIC_DEBUG_INFO(my_debug, "my_debug", 4, 1, 16,
&debug_hex_ascii_view);
2. Add trace entry:
debug_event(&my_debug, 0, "DATA", 4);
Note: The debug area is automatically registered in debugfs during boot.
A driver must not call any of the debug_register()/_unregister()
functions on a static debug_info_t!
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Currently allocation and registration of s390dbf debug areas are tied
together. As a result, a debug area cannot be unregistered and
re-registered while any process has an associated debugfs file open.
Fix this by splitting alloc/release from register/unregister.
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Any previously recorded s390dbf debug data is reset when a debug area
is resized using the 'pages' sysfs attribute. This can make
live-debugging unnecessarily complex.
Fix this by copying existing debug data to the newly allocated debug
area when resizing.
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Avoid that the "restart_part2" label, which is in the middle of a
function, appears in /proc/kallsyms.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Rename amod31 to amode31 like it was supposed to be.
Fixes: c78d0c7484f0 ("s390: rename dma section to amode31")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Both are no longer used since the conversion to generic
entry, therefore remove them.
Fixes: 56e62a737028 ("s390: convert to generic entry")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The memory block occupied by the SCLP early buffer that is allocated
by the decompressor and then handed over to the decompressed kernel,
must be reserved to prevent it from being reused for other purposes.
This is necessary because the SCLP early buffer is still in use
during kernel initialization.
Fixes: f1d3c5323772 ("s390/boot: move sclp early buffer from fixed address in asm to C")
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reported-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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The dma section name is confusing, since the code which resides within
that section has nothing to do with direct memory access. Instead the
limitation is that the code has to run in 31 bit addressing mode, and
therefore has to reside below 2GB. So the name was chosen since
ZONE_DMA is the same region.
To reduce confusion rename the section to amode31, which hopefully
describes better what this is about.
Note: this will also change vmcoreinfo strings
- SDMA=... gets renamed to SAMODE31=...
- EDMA=... gets renamed to EAMODE31=...
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().
Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20210803141621.780504-5-bigeasy@linutronix.de
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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s390 allows hotpatching the mask of a conditional jump instruction.
Make use of this feature in order to avoid the expensive stop_machine()
call.
The new trampolines are split in 3 stages:
- A first stage is a 6-byte relative conditional long branch located at
each function's entry point. Its offset always points to the second
stage for the corresponding function, and its mask is either all 0s
(ftrace off) or all 1s (ftrace on). The code for flipping the mask is
borrowed from ftrace_{enable,disable}_ftrace_graph_caller. After
flipping, ftrace_arch_code_modify_post_process() syncs with all the
other CPUs by sending SIGPs.
- Second stages for vmlinux are stored in a separate part of the .text
section reserved by the linker script, and in dynamically allocated
memory for modules. This prevents the icache pollution. The total
size of second stages is about 1.5% of that of the kernel image.
Putting second stages in the .bss section is possible and decreases
the size of the non-compressed vmlinux, but splits the kernel 1:1
mapping, which is a bad tradeoff.
Each second stage contains a call to the third stage, a pointer to
the part of the intercepted function right after the first stage, and
a pointer to an interceptor function (e.g. ftrace_caller).
Second stages are 8-byte aligned for the future direct calls
implementation.
- There are only two copies of the third stage: in the .text section
for vmlinux and in dynamically allocated memory for modules. It can be
an expoline, which is relatively large, so inlining it into each
second stage is prohibitively expensive.
As a result of this organization, phoronix-test-suite with ftrace off
does not show any performance degradation.
Suggested-by: Sven Schnelle <svens@linux.ibm.com>
Suggested-by: Vasily Gorbik <gor@linux.ibm.com>
Co-developed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20210728212546.128248-3-iii@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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s390x GCC and SystemZ Clang have ThreadSanitizer support now [1] [2],
so enable KCSAN for s390.
[1] https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ea22954e7c58
[2] https://reviews.llvm.org/D105629
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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KCFLAGS="-mno-pic-data-is-text-relative" make leads to bfd assertion
error in s390_got_pointer():
LD arch/s390/kernel/vdso64/vdso64.so.dbg
ld: BFD version 2.35-18.fc33 assertion fail elf-s390-common.c:74
readelf -Wr vdso64_generic.o | grep GOT
0000000000000032 000000110000001a R_390_GOTENT 0000000000000000 _vdso_data + 2
(...)
Add .got.plt in linker script to avoid this.
Suggested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Commit 7f16d7e787b7 ("s390: show virtualization support in /proc/cpuinfo")
introduced special handling for sie capability, saying this should not be
exposed via hwcaps, without giving a reason.
However this leads to an inconsistent /proc/cpuinfo features line
where all features except the sie capability are also present in
hwcaps. I really don't see a reason to not add that to hwcaps - it
might be quite pointless, but at least this way it is possible to get
rid of some special handling.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Remove the not so obvious "(elf_hwcap & (1UL << 2)" which only checks
if stfle is available. This used to be required for old code before
test_facility() was introduced. test_facility() will do the right
thing, regardless if stfle is available or not.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Remove a leftover from the common 31/64 bit code. z/Architecture mode
is now always active, there is no need to check.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Use a consistent coding style within setup_hwcaps() and remove obvious
and outdated comments.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The first six hwcap bits are initialized in a rather odd way: an array
contains the stfl(e) bits which need to be set, so that the
corresponding bit position (= array index) within hwcaps are set.
Better open code it like it is done for all other bits, making it
obvious which bit is set when.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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setup_hwcaps() is a quite large function. Make it smaller by moving
the elf platform setup code into an independent setup function.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Move setup_hwcaps() to processor.c for two reasons:
- make setup.c a bit smaller
- have allmost all of the hwcap code in one file
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Add BUILD_BUG_ON() sanity checks to make sure the hwcap string array
contains a string for each hwcap.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Use named initializers to make it obvious which hwcap string array
element belongs to which hwcap.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Remove s390 part of all HWCAP defines, just to make them shorter and
easier to handle. The namespace is anyway per architecture.
This is similar to what arm64 has.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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In order to support the use of enhanced PCI instructions in both kernel-
and userspace we need both hardware support and proper setup in the
kernel. The latter can be toggled off with the pci=nomio command line
option.
Thus availability of this feature in userspace depends on all of kernel
configuration (CONFIG_PCI), hardware support and the current kernel
command line and can thus not rely solely on a facility bit. Instead
let's introduce a new ELF hardware capability bit HWCAP_S390_PCI_MIO to
tell userspace whether these PCI instructions can be used.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Kernel support for the newer PCI mio instructions can be toggled off
with the pci=nomio command line option which needs to integrate with
common code PCI option parsing. However this option then toggles static
branches which can't be toggled yet in an early_param() call.
Thus commit 9964f396f1d0 ("s390: fix setting of mio addressing control")
moved toggling the static branches to the PCI init routine.
With this setup however we can't check for mio support outside the PCI
code during early boot, i.e. before switching the static branches, which
we need to be able to export this as an ELF HWCAP.
Improve on this by turning mio availability into a machine flag that
gets initially set based on CONFIG_PCI and the facility bit and gets
toggled off if pci=nomio is found during PCI option parsing allowing
simple access to this machine flag after early init.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Add more instructions to the kernel disassembler.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Add hardware capability bits and feature tags to /proc/cpuinfo
for NNPA and Vector-Packed-Decimal-Enhancement Facility 2.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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There is no useful information within [STARTUP_NORMAL_OFFSET, HEAD_END] now.
But the memory region [0, STARTUP_NORMAL_OFFSET] is used by:
* lowcore
* kdump for swapping memory
* stand-alone zipl dumpers for code, data, stack and heap
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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This change simplifies the task of making the decompressor relocatable.
The decompressor's image contains special DMA sections between _sdma and
_edma. This DMA segment is loaded at boot as part of the decompressor and
then simply handed over to the decompressed kernel. The decompressor itself
never uses it in any way. The primary reason for this is the need to keep
the aforementioned DMA segment below 2GB which is required by architecture,
and because the decompressor is always loaded at a fixed low physical
address, it is guaranteed that the DMA region will not cross the 2GB
memory limit. If the DMA region had been placed in the decompressed kernel,
then KASLR would make this guarantee impossible to fulfill or it would
be restricted to the first 2GB of memory address space.
This commit moves all DMA sections between _sdma and _edma from
the decompressor's image to the decompressed kernel's image. The complete
DMA region is placed in the init section of the decompressed kernel and
immediately relocated below 2GB at start-up before it is needed by other
parts of the decompressed kernel. The relocation of the DMA region happens
even if the decompressed kernel is already located below 2GB in order
to keep the first implementation simple. The relocation should not have
any noticeable impact on boot time because the DMA segment is only a couple
of pages.
After relocating the DMA sections, the kernel has to fix all references
which point into it. In order to automate this, place all variables
pointing into the DMA sections in a special .dma.refs section. All such
variables must be defined using the new __dma_ref macro. Only variables
containing addresses within the DMA sections must be placed in the new
.dma.refs section.
Furthermore, move the initialization of control registers from
the decompressor to the decompressed kernel because some control registers
reference tables that must be placed in the DMA data section to
guarantee that their addresses are below 2G. Because the decompressed
kernel relocates the DMA sections at startup, the content of control
registers CR2, CR5 and CR15 must be updated with new addresses after
the relocation. The decompressed kernel initializes all control registers
early at boot and then updates the content of CR2, CR5 and CR15
as soon as the DMA relocation has occurred. This practically reverts
the commit a80313ff91ab ("s390/kernel: introduce .dma sections").
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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To reduce duplication, replace error-prone and hard-coded parameter area
offsets with auto-generated ones.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The new boot data struct shall replace global variables OLDMEM_BASE and
OLDMEM_SIZE. It is initialized in the decompressor and passed
to the decompressed kernel. In comparison to the old solution, this one
doesn't access data at fixed physical addresses which will become important
when the decompressor becomes relocatable.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The new boot data struct shall replace global variables INITRD_START and
INITRD_SIZE. It is initialized in the decompressor and passed
to the decompressed kernel. In comparison to the old solution, this one
doesn't access data at fixed physical addresses which will become important
when the decompressor becomes relocatable.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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De-duplicate checks for Protected Host Virtualization in decompressor and
kernel.
Set prot_virt_host=0 in the decompressor in *any* of the following cases
and hand it over to the decompressed kernel:
* No explicit prot_virt=1 is given on the kernel command-line
* Protected Guest Virtualization is enabled
* Hardware support not present
* kdump or stand-alone dump
The decompressed kernel needs to use only is_prot_virt_host() instead of
performing again all checks done by the decompressor.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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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>
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