Let's get rid of another follow_page() user and perform the conversion
under PTL: Note that this is also what follow_page_pte() ends up doing.
Unfortunately we cannot currently optimize out the additional reference,
because arch_make_folio_accessible() must be called with a raised refcount
to protect against concurrent conversion to secure. We can just move the
arch_make_folio_accessible() under the PTL, like follow_page_pte() would.
We'll effectively drop the "writable" check implied by FOLL_WRITE:
follow_page_pte() would also not check that when calling
arch_make_folio_accessible(), so there is no good reason for doing that
here.
We'll lose the secretmem check from follow_page() as well, about which we
shouldn't really care.
Link: https://lkml.kernel.org/r/20240802155524.517137-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull s390 fixes from Vasily Gorbik:
- Fix KASLR base offset to account for symbol offsets in the vmlinux
ELF file, preventing tool breakages like the drgn debugger
- Fix potential memory corruption of physmem_info during kernel
physical address randomization
- Fix potential memory corruption due to overlap between the relocated
lowcore and identity mapping by correctly reserving lowcore memory
- Fix performance regression and avoid randomizing identity mapping
base by default
- Fix unnecessary delay of AP bus binding complete uevent to prevent
startup lag in KVM guests using AP
* tag 's390-6.11-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/boot: Fix KASLR base offset off by __START_KERNEL bytes
s390/boot: Avoid possible physmem_info segment corruption
s390/ap: Refine AP bus bindings complete processing
s390/mm: Pin identity mapping base to zero
s390/mm: Prevent lowcore vs identity mapping overlap
Symbol offsets to the KASLR base do not match symbol address in
the vmlinux image. That is the result of setting the KASLR base
to the beginning of .text section as result of an optimization.
Revert that optimization and allocate virtual memory for the
whole kernel image including __START_KERNEL bytes as per the
linker script. That allows keeping the semantics of the KASLR
base offset in sync with other architectures.
Rename __START_KERNEL to TEXT_OFFSET, since it represents the
offset of the .text section within the kernel image, rather than
a virtual address.
Still skip mapping TEXT_OFFSET bytes to save memory on pgtables
and provoke exceptions in case an attempt to access this area is
made, as no kernel symbol may reside there.
In case CONFIG_KASAN is enabled the location counter might exceed
the value of TEXT_OFFSET, while the decompressor linker script
forcefully resets it to TEXT_OFFSET, which leads to a sections
overlap link failure. Use MAX() expression to avoid that.
Reported-by: Omar Sandoval <osandov@osandov.com>
Closes: https://lore.kernel.org/linux-s390/ZnS8dycxhtXBZVky@telecaster.dhcp.thefacebook.com/
Fixes: 56b1069c40 ("s390/boot: Rework deployment of the kernel image")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
When physical memory for the kernel image is allocated it does not
consider extra memory required for offsetting the image start to
match it with the lower 20 bits of KASLR virtual base address. That
might lead to kernel access beyond its memory range.
Suggested-by: Vasily Gorbik <gor@linux.ibm.com>
Fixes: 693d41f7c9 ("s390/mm: Restore mapping of kernel image using large pages")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
SIE instruction performs faster when the virtual address of
SIE block matches the physical one. Pin the identity mapping
base to zero for the benefit of SIE and other instructions
that have similar performance impact. Still, randomize the
base when DEBUG_VM kernel configuration option is enabled.
Suggested-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The identity mapping position in virtual memory is randomized
together with the kernel mapping. That position can never
overlap with the lowcore even when the lowcore is relocated.
Prevent overlapping with the lowcore to allow independent
positioning of the identity mapping. With the current value
of the alternative lowcore address of 0x70000 the overlap
could happen in case the identity mapping is placed at zero.
This is a prerequisite for uncoupling of randomization base
of kernel image and identity mapping in virtual memory.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The return value uv_set_shared() and uv_remove_shared() (which are
wrappers around the share() function) is not always checked. The system
integrity of a protected guest depends on the Share and Unshare UVCs
being successful. This means that any caller that fails to check the
return value will compromise the security of the protected guest.
No code path that would lead to such violation of the security
guarantees is currently exercised, since all the areas that are shared
never get unshared during the lifetime of the system. This might
change and become an issue in the future.
The Share and Unshare UVCs can only fail in case of hypervisor
misbehaviour (either a bug or malicious behaviour). In such cases there
is no reasonable way forward, and the system needs to panic.
This patch replaces the return at the end of the share() function with
a panic, to guarantee system integrity.
Fixes: 5abb9351df ("s390/uv: introduce guest side ultravisor code")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20240801112548.85303-1-imbrenda@linux.ibm.com
Message-ID: <20240801112548.85303-1-imbrenda@linux.ibm.com>
[frankja@linux.ibm.com: Fixed up patch subject]
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
We might run into a SIE validity if gisa has been disabled either via using
kernel parameter "kvm.use_gisa=0" or by setting the related sysfs
attribute to N (echo N >/sys/module/kvm/parameters/use_gisa).
The validity is caused by an invalid value in the SIE control block's
gisa designation. That happens because we pass the uninitialized gisa
origin to virt_to_phys() before writing it to the gisa designation.
To fix this we return 0 in kvm_s390_get_gisa_desc() if the origin is 0.
kvm_s390_get_gisa_desc() is used to determine which gisa designation to
set in the SIE control block. A value of 0 in the gisa designation disables
gisa usage.
The issue surfaces in the host kernel with the following kernel message as
soon a new kvm guest start is attemted.
kvm: unhandled validity intercept 0x1011
WARNING: CPU: 0 PID: 781237 at arch/s390/kvm/intercept.c:101 kvm_handle_sie_intercept+0x42e/0x4d0 [kvm]
Modules linked in: vhost_net tap tun xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT xt_tcpudp nft_compat x_tables nf_nat_tftp nf_conntrack_tftp vfio_pci_core irqbypass vhost_vsock vmw_vsock_virtio_transport_common vsock vhost vhost_iotlb kvm nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables sunrpc mlx5_ib ib_uverbs ib_core mlx5_core uvdevice s390_trng eadm_sch vfio_ccw zcrypt_cex4 mdev vfio_iommu_type1 vfio sch_fq_codel drm i2c_core loop drm_panel_orientation_quirks configfs nfnetlink lcs ctcm fsm dm_service_time ghash_s390 prng chacha_s390 libchacha aes_s390 des_s390 libdes sha3_512_s390 sha3_256_s390 sha512_s390 sha256_s390 sha1_s390 sha_common dm_mirror dm_region_hash dm_log zfcp scsi_transport_fc scsi_dh_rdac scsi_dh_emc scsi_dh_alua pkey zcrypt dm_multipath rng_core autofs4 [last unloaded: vfio_pci]
CPU: 0 PID: 781237 Comm: CPU 0/KVM Not tainted 6.10.0-08682-gcad9f11498ea #6
Hardware name: IBM 3931 A01 701 (LPAR)
Krnl PSW : 0704c00180000000 000003d93deb0122 (kvm_handle_sie_intercept+0x432/0x4d0 [kvm])
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
Krnl GPRS: 000003d900000027 000003d900000023 0000000000000028 000002cd00000000
000002d063a00900 00000359c6daf708 00000000000bebb5 0000000000001eff
000002cfd82e9000 000002cfd80bc000 0000000000001011 000003d93deda412
000003ff8962df98 000003d93de77ce0 000003d93deb011e 00000359c6daf960
Krnl Code: 000003d93deb0112: c020fffe7259 larl %r2,000003d93de7e5c4
000003d93deb0118: c0e53fa8beac brasl %r14,000003d9bd3c7e70
#000003d93deb011e: af000000 mc 0,0
>000003d93deb0122: a728ffea lhi %r2,-22
000003d93deb0126: a7f4fe24 brc 15,000003d93deafd6e
000003d93deb012a: 9101f0b0 tm 176(%r15),1
000003d93deb012e: a774fe48 brc 7,000003d93deafdbe
000003d93deb0132: 40a0f0ae sth %r10,174(%r15)
Call Trace:
[<000003d93deb0122>] kvm_handle_sie_intercept+0x432/0x4d0 [kvm]
([<000003d93deb011e>] kvm_handle_sie_intercept+0x42e/0x4d0 [kvm])
[<000003d93deacc10>] vcpu_post_run+0x1d0/0x3b0 [kvm]
[<000003d93deaceda>] __vcpu_run+0xea/0x2d0 [kvm]
[<000003d93dead9da>] kvm_arch_vcpu_ioctl_run+0x16a/0x430 [kvm]
[<000003d93de93ee0>] kvm_vcpu_ioctl+0x190/0x7c0 [kvm]
[<000003d9bd728b4e>] vfs_ioctl+0x2e/0x70
[<000003d9bd72a092>] __s390x_sys_ioctl+0xc2/0xd0
[<000003d9be0e9222>] __do_syscall+0x1f2/0x2e0
[<000003d9be0f9a90>] system_call+0x70/0x98
Last Breaking-Event-Address:
[<000003d9bd3c7f58>] __warn_printk+0xe8/0xf0
Cc: stable@vger.kernel.org
Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Fixes: fe0ef00304 ("KVM: s390: sort out physical vs virtual pointers usage")
Signed-off-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20240801123109.2782155-1-mimu@linux.ibm.com
Message-ID: <20240801123109.2782155-1-mimu@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Since __va(0) does not translate to NULL anymore remove RELOC_HIDE()
which was only added to get rid of a compile warning with clang W=1:
arch/s390/mm/vmem.c:666:36: warning: performing pointer arithmetic on
a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
666 | __set_memory_4k(__va(0), __va(0) + ident_map_size);
| ~~~~~~~ ^
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Use the sort() from lib/sort.c to sort markers instead of the private
implementation. The current implementation does not sort markers
properly if they have to be moved downwards:
---[ Real Memory Copy Area Start ]---
0x0000035b903ff000-0x0000035b90400000 4K PTE I
---[ vmalloc Area Start ]---
---[ Real Memory Copy Area End ]---
Add a new member to each marker which indicates if a marker is start
of an area. If addresses of areas are equal consider an address which
defines the start of an area higher than the address which defines the
end of an area. In result the output is sorted as intended:
---[ Real Memory Copy Area Start ]---
0x0000019cedcff000-0x0000019cedd00000 4K PTE I
---[ Real Memory Copy Area End ]---
---[ vmalloc Area Start ]---
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The page table dumper contains a hard coded assumption that the first
mapped area starts at address zero. With a relocated lowcore this is
not true anymore. Subsequently the first entry (lowcore) is printed as
if it would contain everything from address zero until the end of the
location of the lowcore area.
Fix this by adding a single "Kernel Virtual Address Space" entry,
which always starts at address zero. It ends when the lowcore area
starts which is either address zero, or its relocated address.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Since virtual and real addresses are not the same anymore the
assumption that the kernel image is contained within the identity
mapping is also not true anymore.
Fix this by adding two explicit areas and at the correct locations: one
for the 8kb lowcore area, and one for the identity mapping.
Fixes: c98d2ecae0 ("s390/mm: Uncouple physical vs virtual address spaces")
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Remove the unused and empty arch/s390/kernel/alternative.h header
file which was added by mistake.
Fixes: 5ade5be4ed ("s390: Add infrastructure to patch lowcore accesses")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
With the recent rewrite of the fpu code exception handling for the
lfpc instruction within load_fpu_state() was erroneously removed.
Add it again to prevent that loading invalid floating point register
values cause an unhandled specification exception.
Fixes: 8c09871a95 ("s390/fpu: limit save and restore to used registers")
Cc: stable@vger.kernel.org
Reported-by: Aristeu Rozanski <aris@redhat.com>
Tested-by: Aristeu Rozanski <aris@redhat.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Pull more s390 updates from Vasily Gorbik:
- Fix KMSAN build breakage caused by the conflict between s390 and
mm-stable trees
- Add KMSAN page markers for ptdump
- Add runtime constant support
- Fix __pa/__va for modules under non-GPL licenses by exporting
necessary vm_layout struct with EXPORT_SYMBOL to prevent linkage
problems
- Fix an endless loop in the CF_DIAG event stop in the CPU Measurement
Counter Facility code when the counter set size is zero
- Remove the PROTECTED_VIRTUALIZATION_GUEST config option and enable
its functionality by default
- Support allocation of multiple MSI interrupts per device and improve
logging of architecture-specific limitations
- Add support for lowcore relocation as a debugging feature to catch
all null ptr dereferences in the kernel address space, improving
detection beyond the current implementation's limited write access
protection
- Clean up and rework CPU alternatives to allow for callbacks and early
patching for the lowcore relocation
* tag 's390-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits)
s390: Remove protvirt and kvm config guards for uv code
s390/boot: Add cmdline option to relocate lowcore
s390/kdump: Make kdump ready for lowcore relocation
s390/entry: Make system_call() ready for lowcore relocation
s390/entry: Make ret_from_fork() ready for lowcore relocation
s390/entry: Make __switch_to() ready for lowcore relocation
s390/entry: Make restart_int_handler() ready for lowcore relocation
s390/entry: Make mchk_int_handler() ready for lowcore relocation
s390/entry: Make int handlers ready for lowcore relocation
s390/entry: Make pgm_check_handler() ready for lowcore relocation
s390/entry: Add base register to CHECK_VMAP_STACK/CHECK_STACK macro
s390/entry: Add base register to SIEEXIT macro
s390/entry: Add base register to MBEAR macro
s390/entry: Make __sie64a() ready for lowcore relocation
s390/head64: Make startup code ready for lowcore relocation
s390: Add infrastructure to patch lowcore accesses
s390/atomic_ops: Disable flag outputs constraint for GCC versions below 14.2.0
s390/entry: Move SIE indicator flag to thread info
s390/nmi: Simplify ptregs setup
s390/alternatives: Remove alternative facility list
...
Pull sysctl constification from Joel Granados:
"Treewide constification of the ctl_table argument of proc_handlers
using a coccinelle script and some manual code formatting fixups.
This is a prerequisite to moving the static ctl_table structs into
read-only data section which will ensure that proc_handler function
pointers cannot be modified"
* tag 'constfy-sysctl-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
sysctl: treewide: constify the ctl_table argument of proc_handlers
Pull driver core updates from Greg KH:
"Here is the big set of driver core changes for 6.11-rc1.
Lots of stuff in here, with not a huge diffstat, but apis are evolving
which required lots of files to be touched. Highlights of the changes
in here are:
- platform remove callback api final fixups (Uwe took many releases
to get here, finally!)
- Rust bindings for basic firmware apis and initial driver-core
interactions.
It's not all that useful for a "write a whole driver in rust" type
of thing, but the firmware bindings do help out the phy rust
drivers, and the driver core bindings give a solid base on which
others can start their work.
There is still a long way to go here before we have a multitude of
rust drivers being added, but it's a great first step.
- driver core const api changes.
This reached across all bus types, and there are some fix-ups for
some not-common bus types that linux-next and 0-day testing shook
out.
This work is being done to help make the rust bindings more safe,
as well as the C code, moving toward the end-goal of allowing us to
put driver structures into read-only memory. We aren't there yet,
but are getting closer.
- minor devres cleanups and fixes found by code inspection
- arch_topology minor changes
- other minor driver core cleanups
All of these have been in linux-next for a very long time with no
reported problems"
* tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
ARM: sa1100: make match function take a const pointer
sysfs/cpu: Make crash_hotplug attribute world-readable
dio: Have dio_bus_match() callback take a const *
zorro: make match function take a const pointer
driver core: module: make module_[add|remove]_driver take a const *
driver core: make driver_find_device() take a const *
driver core: make driver_[create|remove]_file take a const *
firmware_loader: fix soundness issue in `request_internal`
firmware_loader: annotate doctests as `no_run`
devres: Correct code style for functions that return a pointer type
devres: Initialize an uninitialized struct member
devres: Fix memory leakage caused by driver API devm_free_percpu()
devres: Fix devm_krealloc() wasting memory
driver core: platform: Switch to use kmemdup_array()
driver core: have match() callback in struct bus_type take a const *
MAINTAINERS: add Rust device abstractions to DRIVER CORE
device: rust: improve safety comments
MAINTAINERS: add Danilo as FIRMWARE LOADER maintainer
MAINTAINERS: add Rust FW abstractions to FIRMWARE LOADER
firmware: rust: improve safety comments
...
const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.
This patch has been generated by the following coccinelle script:
```
virtual patch
@r1@
identifier ctl, write, buffer, lenp, ppos;
identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
@@
int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int write, void *buffer, size_t *lenp, loff_t *ppos);
@r2@
identifier func, ctl, write, buffer, lenp, ppos;
@@
int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int write, void *buffer, size_t *lenp, loff_t *ppos)
{ ... }
@r3@
identifier func;
@@
int func(
- struct ctl_table *
+ const struct ctl_table *
,int , void *, size_t *, loff_t *);
@r4@
identifier func, ctl;
@@
int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int , void *, size_t *, loff_t *);
@r5@
identifier func, write, buffer, lenp, ppos;
@@
int func(
- struct ctl_table *
+ const struct ctl_table *
,int write, void *buffer, size_t *lenp, loff_t *ppos);
```
* Code formatting was adjusted in xfs_sysctl.c to comply with code
conventions. The xfs_stats_clear_proc_handler,
xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
adjusted.
* The ctl_table argument in proc_watchdog_common was const qualified.
This is called from a proc_handler itself and is calling back into
another proc_handler, making it necessary to change it as part of the
proc_handler migration.
Co-developed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Co-developed-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Joel Granados <j.granados@samsung.com>
Pull Kbuild updates from Masahiro Yamada:
- Remove tristate choice support from Kconfig
- Stop using the PROVIDE() directive in the linker script
- Reduce the number of links for the combination of CONFIG_KALLSYMS and
CONFIG_DEBUG_INFO_BTF
- Enable the warning for symbol reference to .exit.* sections by
default
- Fix warnings in RPM package builds
- Improve scripts/make_fit.py to generate a FIT image with separate
base DTB and overlays
- Improve choice value calculation in Kconfig
- Fix conditional prompt behavior in choice in Kconfig
- Remove support for the uncommon EMAIL environment variable in Debian
package builds
- Remove support for the uncommon "name <email>" form for the DEBEMAIL
environment variable
- Raise the minimum supported GNU Make version to 4.0
- Remove stale code for the absolute kallsyms
- Move header files commonly used for host programs to scripts/include/
- Introduce the pacman-pkg target to generate a pacman package used in
Arch Linux
- Clean up Kconfig
* tag 'kbuild-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (65 commits)
kbuild: doc: gcc to CC change
kallsyms: change sym_entry::percpu_absolute to bool type
kallsyms: unify seq and start_pos fields of struct sym_entry
kallsyms: add more original symbol type/name in comment lines
kallsyms: use \t instead of a tab in printf()
kallsyms: avoid repeated calculation of array size for markers
kbuild: add script and target to generate pacman package
modpost: use generic macros for hash table implementation
kbuild: move some helper headers from scripts/kconfig/ to scripts/include/
Makefile: add comment to discourage tools/* addition for kernel builds
kbuild: clean up scripts/remove-stale-files
kconfig: recursive checks drop file/lineno
kbuild: rpm-pkg: introduce a simple changelog section for kernel.spec
kallsyms: get rid of code for absolute kallsyms
kbuild: Create INSTALL_PATH directory if it does not exist
kbuild: Abort make on install failures
kconfig: remove 'e1' and 'e2' macros from expression deduplication
kconfig: remove SYMBOL_CHOICEVAL flag
kconfig: add const qualifiers to several function arguments
kconfig: call expr_eliminate_yn() at least once in expr_eliminate_dups()
...
Removing the CONFIG_PROTECTED_VIRTUALIZATION_GUEST ifdefs and config
option as well as CONFIG_KVM ifdefs in uv files.
Having this configurable has been more of a pain than a help.
It's time to remove the ifdefs and the config option.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Now that everything has been converted, add the option
'relocate_lowcore' to enable relocating the lowcore.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in store_status()
and __do_machine_kdump().
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in system_call().
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in ret_from_fork().
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in __switch_to().
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in restart_int_handler().
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in mcck_int_handler().
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in the ext/io interrupt
handlers.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in pgm_check_handler().
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to CHECK_VMAP_STACK and CHECK_STACK. No
functional change, because %r0 is passed to the macro.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to SIEEXIT. No functional change, because
%r0 is passed to the macro.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to MBEAR. No functional change, because
%r0 is passed to the macro.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in __sie64a().
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in startup_continue().
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The s390 architecture defines two special per-CPU data pages
called the "prefix area". In s390-linux terminology this is usually
called "lowcore". This memory area contains system configuration
data like old/new PSW's for system call/interrupt/machine check
handlers and lots of other data. It is normally mapped to logical
address 0. This area can only be accessed when in supervisor mode.
This means that kernel code can dereference NULL pointers, because
accesses to address 0 are allowed. Parts of lowcore can be write
protected, but read accesses and write accesses outside of the write
protected areas are not caught.
To remove this limitation for debugging and testing, remap lowcore to
another address and define a function get_lowcore() which simply
returns the address where lowcore is mapped at. This would normally
introduce a pointer dereference (=memory read). As lowcore is used
for several very often used variables, add code to patch this function
during runtime, so we avoid the memory reads.
For C code get_lowcore() has to be used, for assembly code it is
the GET_LC macro. When using this macro/function a reference is added
to alternative patching. All these locations will be patched to the
actual lowcore location when the kernel is booted or a module is loaded.
To make debugging/bisecting problems easier, this patch adds all the
infrastructure but the lowcore address is still hardwired to 0. This
way the code can be converted on a per function basis, and the
functionality is enabled in a patch after all the functions have
been converted.
Note that this requires at least z16 because the old lpsw instruction
only allowed a 12 bit displacement. z16 introduced lpswey which allows
20 bits (signed), so the lowcore can effectively be mapped from
address 0 - 0x7e000. To use 0x7e000 as address, a 6 byte lgfi
instruction would have to be used in the alternative. To save two
bytes, llilh can be used, but this only allows to set bits 16-31 of
the address. In order to use the llilh instruction, use 0x70000 as
alternative lowcore address. This is still large enough to catch
NULL pointer dereferences into large arrays.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
CIF_SIE indicates if a thread is running in SIE context. This is the
state of a thread and not the CPU. Therefore move this indicator to
thread info.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The low level machine check handler code fills the ptregs structure
partially with the register contents present at machine check handler
entry and partially with contents from the machine check save area.
In case of a machine check the contents of all general purpose
registers are saved by the CPU to the machine check save area.
Therefore simplify the code and fill the ptregs structure by only
using the machine check save area as source.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The alternative and the normal facility list are always identical. Remove
the alternative facility list, which allows to simplify the alternatives
code.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The nospec implementation is deeply integrated into the alternatives
code: only for nospec an alternative facility list is implemented and
used by the alternative code, while it is modified by nospec specific
needs.
Push down the nospec alternative handling into the nospec by
introducing a new alternative type and a specific nospec callback to
decide if alternatives should be applied.
Also introduce a new global nobp variable which together with facility
82 can be used to decide if nobp is enabled or not.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Add the required code to patch alternatives early in the decompressor.
This is required for the upcoming lowcore relocation changes, where
alternatives for facility 193 need to get patched before lowcore
alternatives.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Co-developed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Rework alternatives to allow for callbacks. With this every
alternative entry has additional data encoded:
- When (aka context) an alternative is supposed to be applied
- The type of an alternative, which allows for type specific handling
and callbacks
- Extra type specific payload (patch information), which can be passed
to callbacks in order to decide if an alternative should be applied
or not
With this only the "late" context is implemented, which means there is
no change to the previous behaviour. All code is just converted to the
more generic new infrastructure.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
To avoid lots of ifdefs in C code make s390_kernel_write() usable for
the decompressor: simply use memcpy() for this case since there is no
write protection enabled that early.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Move all text sync functions from alternative.c to processor.c. This
way there is only minimal code left in alternative.c left, which is a
prerequisite to use the C file within boot code as well.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The two alternative header files must stay in sync. This is easier to
achieve within one header file. Therefore merge both of them and have
only one file, like most other architectures.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
