Commit Graph

8900 Commits

Author SHA1 Message Date
Vasily Gorbik
39da9a979c s390/boot: remove pgtable_populate_end
setup_vmem() already calls populate for all online memory regions.
pgtable_populate_end() could be removed.

Also rename pgtable_populate_begin() to pgtable_populate_init().

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-31 18:56:36 +01:00
Vasily Gorbik
e966ccf836 s390/boot: avoid mapping standby memory
Commit bb1520d581 ("s390/mm: start kernel with DAT enabled")
doesn't consider online memory holes due to potential memory offlining
and erroneously creates pgtables for stand-by memory, which bear RW+X
attribute and trigger a warning:

RANGE                                 SIZE   STATE REMOVABLE BLOCK
0x0000000000000000-0x0000000c3fffffff  49G  online       yes  0-48
0x0000000c40000000-0x0000000c7fffffff   1G offline              49
0x0000000c80000000-0x0000000fffffffff  14G  online       yes 50-63
0x0000001000000000-0x00000013ffffffff  16G offline           64-79

    s390/mm: Found insecure W+X mapping at address 0xc40000000
    WARNING: CPU: 14 PID: 1 at arch/s390/mm/dump_pagetables.c:142 note_page+0x2cc/0x2d8

Map only online memory ranges which fit within identity mapping limit.

Fixes: bb1520d581 ("s390/mm: start kernel with DAT enabled")
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-31 18:56:36 +01:00
Heiko Carstens
2213d44e14 s390/syscalls: get rid of system call alias functions
bpftrace and friends only consider functions present in
/sys/kernel/tracing/available_filter_functions.

For system calls there is the s390 specific problem that the system call
function itself is present via __se_sys##name() while the system call
itself is wired up via an __s390x_sys##name() alias. The required DWARF
debug information however is only available for the original function, not
the alias, but within available_filter_functions only the functions with
__s390x_ prefix are available. Which means the required DWARF debug
information cannot be found.
While this could be solved via tooling, it is easier to change the s390
specific system call wrapper handling.

Therefore get rid of this alias handling and implement system call wrappers
like most other architectures are doing. In result the implementation
generates the following functions:

long __s390x_sys##name(struct pt_regs *regs)
static inline long __se_sys##name(...)
static inline long __do_sys##name(...)

__s390x_sys##name() is the visible system call function which is also wired
up in the system call table. Its only parameter is a pt_regs variable.

This function calls the corresponding __se_sys##name() function, which has
as many parameters like the system call definition. This function in turn
performs all zero and sign extensions of all system call parameters, taken
from the pt_regs structure, and finally calls __do_sys##name().

__do_sys##name() is the actual inlined system call function implementation.

For all 64 bit system calls there is a 31/32 bit system call function
__s390_sys##name() generated, which handles all system call parameters
correctly as required by compat handling. This function may be wired
up within the compat system call table, unless there exists an
explicit compat system call function, which is then used instead.

Reported-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:11 +01:00
Heiko Carstens
0efc5d58bd s390/syscalls: remove trailing semicolon
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:11 +01:00
Heiko Carstens
2e4532d4ac s390/syscalls: move __S390_SYS_STUBx() macro
Move __S390_SYS_STUBx() the end of the CONFIG_COMPAT section, so both
variants (compat and non-compat) are close together and can be easily
compared.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:11 +01:00
Heiko Carstens
82c1b3e7e5 s390/syscalls: remove __SC_COMPAT_TYPE define
Remove __SC_COMPAT_TYPE define which is an unused leftover.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:11 +01:00
Heiko Carstens
7be215ba35 s390/syscalls: remove SYSCALL_METADATA() from compat syscalls
SYSCALL_METADATA() is only supposed to be used for non-compat system
calls. Otherwise there would be a name clash.

This also removes the inconsistency that s390 is the only architecture
which uses SYSCALL_METADATA() for compat system calls, and even that only
for compat system calls without parameters. Only two such compat system
calls exist.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:11 +01:00
Ilya Leoshkevich
e9c9cb90e7 s390: discard .interp section
When debugging vmlinux with QEMU + GDB, the following GDB error may
occur:

    (gdb) c
    Continuing.
    Warning:
    Cannot insert breakpoint -1.
    Cannot access memory at address 0xffffffffffff95c0

    Command aborted.
    (gdb)

The reason is that, when .interp section is present, GDB tries to
locate the file specified in it in memory and put a number of
breakpoints there (see enable_break() function in gdb/solib-svr4.c).
Sometimes GDB finds a bogus location that matches its heuristics,
fails to set a breakpoint and stops. This makes further debugging
impossible.

The .interp section contains misleading information anyway (vmlinux
does not need ld.so), so fix by discarding it.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:10 +01:00
Thomas Richter
0d5f0dc830 s390/cpum_cf: simplify PMC_INIT and PMC_RELEASE usage
Simplify the use of constants PMC_INIT and PMC_RELEASE.

Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:10 +01:00
Thomas Richter
1e99c242ac s390/cpum_cf: merge source files for CPU Measurement counter facility
With no in-kernel user, the source files can be merged.

Move all functions and the variable definitions to file perf_cpum_cf.c
This file now contains all the necessary functions and definitions
for the CPU Measurement counter facility device driver.

The files cpu_mcf.h and perf_cpum_cf_common.c are deleted.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:10 +01:00
Thomas Richter
ea53e6995f s390/cpum_cf: remove in-kernel counting facility interface
Commit 17bebcc68e ("s390/cpum_cf: Add minimal in-kernel interface for
counter measurements") introduced a small in-kernel interface for CPU
Measurement counter facility.
There are no users of this interface, therefore remove it.

The following functions are removed:
 kernel_cpumcf_alert(),
 kernel_cpumcf_begin(),
 kernel_cpumcf_end(),
 kernel_cpumcf_avail()
there is no need for them anymore.
With the removal of function kernel_cpumcf_alert(), also remove
member alert in struct cpu_cf_events. Its purpose was to counter
measurement alert interrupts for the in-kernel interface.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:10 +01:00
Thomas Richter
7a8f09ac18 s390/cpum_cf: move stccm_avail()
Function stccm_avail() is defined in a header file and the
only user is one single source file. Move this function to the source
file where it is also used and remove it from the header file.
No functional change.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:10 +01:00
Thomas Richter
345d2a4dcd s390/cpum_cf: move cpum_cf_ctrset_size()
Function cpum_cf_ctrset_size() is defined in one source file and the
only user is in another source file. Move this function to the source
file where it is used and remove its prototype from the header file.
No functional change.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:09 +01:00
Thomas Richter
1ce357cb82 s390/cpum_cf: simplify hw_perf_event_destroy()
To remove an event from the CPU Measurement counter facility
use the lock/unlock scheme as done in event creation. Remove
the atomic_add_unless function to make the code easier.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:09 +01:00
Heiko Carstens
7a725b7702 s390/cache: change type from unsigned long long to unsigned long
The unsigned long long type is a leftover of the 31 bit area.
Get rid of it.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:09 +01:00
Vasily Gorbik
1a280f48c0 s390/kprobes: replace kretprobe with rethook
That's an adaptation of commit f3a112c0c4 ("x86,rethook,kprobes:
Replace kretprobe with rethook on x86") to s390.

Replaces the kretprobe code with rethook on s390. With this patch,
kretprobe on s390 uses the rethook instead of kretprobe specific
trampoline code.

Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-22 18:42:35 +01:00
Thomas Richter
d924ecdb70 s390/cpum_sf: diagnostic sampling buffer setup to handle virtual addresses
The CPU Measurement Sampling Facility (CPUM_SF) installs large buffers
to save samples collected by hardware. These buffers are organized
as Sample Data Buffer Tables (SDBT) and Sample Data Buffers (SDB).
SDBs contain the samples which are extracted and saved in the perf
ring buffer.
The SDBTs are chained using real addresses and refer to SDBs using
real addresses.

The diagnostic sampling setup uses buffers provided by the process
which invokes perf_event_open system call. The buffers are memory
mapped. The buffers have been allocated by the kernel event
subsystem.

Add proper virtual to phyiscal address translation to the buffer
chaining. The current constraint which requires virtual equals
real address layout is removed.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-22 18:42:35 +01:00
Thomas Richter
78157b4791 s390/cpum_sf: rework macro AUX_SDB_NUM_xxx
Macro AUX_SDB_NUM() has three parameters. The first one is not used.
Remove the first parameter. Also convert the macros to inline functions.
No functional change.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-22 18:42:35 +01:00
Thomas Richter
1f8e50722f s390/cpum_sf: sampling buffer setup to handle virtual addresses
The CPU Measurement Sampling Facility (CPUM_SF) installs large buffers
to save samples collected by hardware. These buffers are organized
as Sample Data Buffer Tables (SDBT) and Sample Data Buffers (SDB).
SDBs contain the samples which are extracted and saved in the perf
ring buffer.
The SDBTs are chained using real addresses and refer to SDBs using
real addresses.

Adds proper virtual to phyiscal address translation to the buffer
chaining. The current constraint which requires virtual equals real
address layout is removed.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-22 18:42:35 +01:00
Thomas Richter
4012fc20e2 s390/cpum_sf: remove debug statements from function setup_pmc_cpu
Remove debug statements from function setup_pmc_cpu().
The debug statement displays a pointer value to a per cpu variable.
This pointer value is printed nowhere else, so it has no use for
cross reference.
No functional change.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-22 18:42:34 +01:00
Thomas Richter
a64e45c2ea s390/cpum_sf: move functions from header file to source file
Some inline helper functions are defined in a header file but used
in only one source file. Move these functions to the source file.
No functional change.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-22 18:42:34 +01:00
Jiapeng Chong
b4af09140a s390/vmem: use swap() instead of open coding it
Swap is a function interface that provides exchange function. To avoid
code duplication, we can use swap function.

./arch/s390/mm/vmem.c:680:10-11: WARNING opportunity for swap().

[hca@linux.ibm.com: get rid of all temp variables]
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3786
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230117060223.58583-1-jiapeng.chong@linux.alibaba.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-22 18:42:34 +01:00
Christophe JAILLET
c313094491 s390/ipl: use kstrtobool() instead of strtobool()
strtobool() is the same as kstrtobool().
However, the latter is more used within the kernel.

In order to remove strtobool() and slightly simplify kstrtox.h, switch to
the other function name.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/58a3ed2e21903a93dfd742943b1e6936863ca037.1673708887.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-22 18:42:34 +01:00
Heiko Carstens
706a91be38 Merge branch 'fixes' into features
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-17 19:12:39 +01:00
Heiko Carstens
41e1992665 s390: workaround invalid gcc-11 out of bounds read warning
GCC 11.1.0 and 11.2.0 generate a wrong warning when compiling the
kernel e.g. with allmodconfig:

arch/s390/kernel/setup.c: In function ‘setup_lowcore_dat_on’:
./include/linux/fortify-string.h:57:33: error: ‘__builtin_memcpy’ reading 128 bytes from a region of size 0 [-Werror=stringop-overread]
...
arch/s390/kernel/setup.c:526:9: note: in expansion of macro ‘memcpy’
  526 |         memcpy(abs_lc->cregs_save_area, S390_lowcore.cregs_save_area,
      |         ^~~~~~

This could be addressed by using absolute_pointer() with the
S390_lowcore macro, but this is not a good idea since this generates
worse code for performance critical paths.

Therefore simply use a for loop to copy the array in question and get
rid of the warning.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-17 19:00:59 +01:00
Heiko Carstens
760c6ce64b s390: move __amode31_base declaration to proper header file
Move __amode31_base declaration to proper header file to get rid of

arch/s390/boot/startup.c:24:15:
 warning: symbol '__amode31_base' was not declared. Should it be static?

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-13 14:15:07 +01:00
Alexander Gordeev
2154e0b328 s390/mm: allocate Absolute Lowcore Area in decompressor
Move Absolute Lowcore Area allocation to the decompressor.
As result, get_abs_lowcore() and put_abs_lowcore() access
brackets become really straight and do not require complex
execution context analysis and LAP and interrupts tackling.

Reviewed-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>
2023-01-13 14:15:06 +01:00
Alexander Gordeev
8e9205d2a5 s390/mm: allocate Real Memory Copy Area in decompressor
Move Real Memory Copy Area allocation to the decompressor.
As result, memcpy_real() and memcpy_real_iter() movers
become usable since the very moment the kernel starts.

Reviewed-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>
2023-01-13 14:15:06 +01:00
Alexander Gordeev
e0e0a87b4b s390/boot: allow setup of different virtual address types
Currently the decompressor sets up only identity mapping.
Allow adding more address range types as a prerequisite
for allocation of kernel fixed mappings.

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-13 14:15:06 +01:00
Alexander Gordeev
07493a9ca7 s390/kasan: remove identity mapping support
The identity mapping is created in the decompressor,
there is no need to have the same functionality in
the kasan setup code. Thus, remove it.

Remove the 4KB pages check for first 1MB since there
is no need to take care of the lowcore pages.

Acked-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>
2023-01-13 14:15:06 +01:00
Alexander Gordeev
12cf6473d2 s390/maccess: remove dead DAT-off code
As the kernel is executed in DAT-on mode only, remove
unnecessary DAT bit check together with the dead code.

Reviewed-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>
2023-01-13 14:15:05 +01:00
Alexander Gordeev
bb1520d581 s390/mm: start kernel with DAT enabled
The setup of the kernel virtual address space is spread
throughout the sources, boot stages and config options
like this:

1. The available physical memory regions are queried
   and stored as mem_detect information for later use
   in the decompressor.

2. Based on the physical memory availability the virtual
   memory layout is established in the decompressor;

3. If CONFIG_KASAN is disabled the kernel paging setup
   code populates kernel pgtables and turns DAT mode on.
   It uses the information stored at step [1].

4. If CONFIG_KASAN is enabled the kernel early boot
   kasan setup populates kernel pgtables and turns DAT
   mode on. It uses the information stored at step [1].

   The kasan setup creates early_pg_dir directory and
   directly overwrites swapper_pg_dir entries to make
   shadow memory pages available.

Move the kernel virtual memory setup to the decompressor
and start the kernel with DAT turned on right from the
very first istruction. That completely eliminates the
boot phase when the kernel runs in DAT-off mode, simplies
the overall design and consolidates pgtables setup.

The identity mapping is created in the decompressor, while
kasan shadow mappings are still created by the early boot
kernel code.

Share with decompressor the existing kasan memory allocator.
It decreases the size of a newly requested memory block from
pgalloc_pos and ensures that kernel image is not overwritten.
pgalloc_low and pgalloc_pos pointers are made preserved boot
variables for that.

Use the bootdata infrastructure to setup swapper_pg_dir
and invalid_pg_dir directories used by the kernel later.
The interim early_pg_dir directory established by the
kasan initialization code gets eliminated as result.

As the kernel runs in DAT-on mode only the PSW_KERNEL_BITS
define gets PSW_MASK_DAT bit by default. Additionally, the
setup_lowcore_dat_off() and setup_lowcore_dat_on() routines
get merged, since there is no DAT-off mode stage anymore.

The memory mappings are created with RW+X protection that
allows the early boot code setting up all necessary data
and services for the kernel being booted. Just before the
paging is enabled the memory protection is changed to
RO+X for text, RO+NX for read-only data and RW+NX for
kernel data and the identity mapping.

Reviewed-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>
2023-01-13 14:15:05 +01:00
Alexander Gordeev
bd50b74362 s390/boot: detect and enable memory facilities
Detect and enable memory facilities which is a
prerequisite for pgtables setup in the decompressor.

Reviewed-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>
2023-01-13 14:15:05 +01:00
Alexander Gordeev
b265854060 s390/pgtable: add REGION3_KERNEL_EXEC protection
Similar to existing PAGE_KERNEL_EXEC and SEGMENT_KERNEL_EXEC
memory protection add REGION3_KERNEL_EXEC attribute that
could be set on PUD pgtable entries.

Reviewed-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>
2023-01-13 14:15:05 +01:00
Alexander Gordeev
bf2b4af2ed s390/kasan: use set_pXe_bit() for pgtable entries setup
Convert setup of pgtable entries to use set_pXe_bit()
helpers as the preferred way in MM code.

Locally introduce pgprot_clear_bit() helper, which is
strictly speaking a generic function. However, it is
only x86 pgprot_clear_protnone_bits() helper, which
does a similar thing, so do not make it public.

Reviewed-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>
2023-01-13 14:15:05 +01:00
Alexander Gordeev
e148071b9f s390/kasan: cleanup setup of untracked memory pgtables
Avoid duplicate IS_ENABLED(CONFIG_KASAN_VMALLOC) condition check.

Reviewed-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>
2023-01-13 14:15:04 +01:00
Alexander Gordeev
8772555ad0 s390/kasan: cleanup setup of zero pgtable
Fix variables initialization coding style and setup zero
pgtable same way region and segment pgtables are set up.

Reviewed-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>
2023-01-13 14:15:04 +01:00
Alexander Gordeev
aae2f753d2 s390/kasan: sort out physical vs virtual memory confusion
The kasan early boot memory allocators operate on pgalloc_pos
and segment_pos physical address pointers, but fail to convert
it to the corresponding virtual pointers.

Currently it is not a problem, since virtual and physical
addresses on s390 are the same. Nevertheless, should they
ever differ, this would cause an invalid pointer access.

Reviewed-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>
2023-01-13 14:15:04 +01:00
Alexander Gordeev
639886b71d s390/early: fix sclp_early_sccb variable lifetime
Commit ada1da31ce ("s390/sclp: sort out physical vs
virtual pointers usage") fixed the notion of virtual
address for sclp_early_sccb pointer. However, it did
not take into account that kasan_early_init() can also
output messages and sclp_early_sccb should be adjusted
by the time kasan_early_init() is called.

Currently it is not a problem, since virtual and physical
addresses on s390 are the same. Nevertheless, should they
ever differ, this would cause an invalid pointer access.

Fixes: ada1da31ce ("s390/sclp: sort out physical vs virtual pointers usage")
Reviewed-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>
2023-01-13 14:15:04 +01:00
Alexander Gordeev
9c3205b2b0 s390/boot: cleanup decompressor header files
Move declarations to appropriate header files. Instead of cryptic
casting directly assign struct vmlinux_info type to _vmlinux_info
linker script variable - wich it actually is.

Reviewed-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>
2023-01-13 14:15:04 +01:00
Heiko Carstens
1ecf7bd9c2 s390: update defconfigs
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-11 21:26:40 +01:00
Heiko Carstens
42400d99e9 KVM: s390: interrupt: use READ_ONCE() before cmpxchg()
Use READ_ONCE() before cmpxchg() to prevent that the compiler generates
code that fetches the to be compared old value several times from memory.

Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20230109145456.2895385-1-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-11 15:28:47 +01:00
Heiko Carstens
e3f360db08 s390/percpu: add READ_ONCE() to arch_this_cpu_to_op_simple()
Make sure that *ptr__ within arch_this_cpu_to_op_simple() is only
dereferenced once by using READ_ONCE(). Otherwise the compiler could
generate incorrect code.

Cc: <stable@vger.kernel.org>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-11 15:28:47 +01:00
Heiko Carstens
82d3edb50a s390/cpum_sf: add READ_ONCE() semantics to compare and swap loops
The current cmpxchg_double() loops within the perf hw sampling code do not
have READ_ONCE() semantics to read the old value from memory. This allows
the compiler to generate code which reads the "old" value several times
from memory, which again allows for inconsistencies.

For example:

        /* Reset trailer (using compare-double-and-swap) */
        do {
                te_flags = te->flags & ~SDB_TE_BUFFER_FULL_MASK;
                te_flags |= SDB_TE_ALERT_REQ_MASK;
        } while (!cmpxchg_double(&te->flags, &te->overflow,
                 te->flags, te->overflow,
                 te_flags, 0ULL));

The compiler could generate code where te->flags used within the
cmpxchg_double() call may be refetched from memory and which is not
necessarily identical to the previous read version which was used to
generate te_flags. Which in turn means that an incorrect update could
happen.

Fix this by adding READ_ONCE() semantics to all cmpxchg_double()
loops. Given that READ_ONCE() cannot generate code on s390 which atomically
reads 16 bytes, use a private compare-and-swap-double implementation to
achieve that.

Also replace cmpxchg_double() with the private implementation to be able to
re-use the old value within the loops.

As a side effect this converts the whole code to only use bit fields
to read and modify bits within the hws trailer header.

Reported-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Reviewed-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/linux-s390/Y71QJBhNTIatvxUT@osiris/T/#ma14e2a5f7aa8ed4b94b6f9576799b3ad9c60f333
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-11 15:28:34 +01:00
Heiko Carstens
e7b4816971 s390/archrandom: add missing header include
Add missing header include to get rid of

arch/s390/crypto/arch_random.c:15:1:
 warning: symbol 's390_arch_random_available' was not declared. Should it be static?
arch/s390/crypto/arch_random.c:17:12:
 warning: symbol 's390_arch_random_counter' was not declared. Should it be static?

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-10 14:39:08 +01:00
Alexander Egorenkov
c2337a40e0 s390/kexec: fix ipl report address for kdump
This commit addresses the following erroneous situation with file-based
kdump executed on a system with a valid IPL report.

On s390, a kdump kernel, its initrd and IPL report if present are loaded
into a special and reserved on boot memory region - crashkernel. When
a system crashes and kdump was activated before, the purgatory code
is entered first which swaps the crashkernel and [0 - crashkernel size]
memory regions. Only after that the kdump kernel is entered. For this
reason, the pointer to an IPL report in lowcore must point to the IPL report
after the swap and not to the address of the IPL report that was located in
crashkernel memory region before the swap. Failing to do so, makes the
kdump's decompressor try to read memory from the crashkernel memory region
which already contains the production's kernel memory.

The situation described above caused spontaneous kdump failures/hangs
on systems where the Secure IPL is activated because on such systems
an IPL report is always present. In that case kdump's decompressor tried
to parse an IPL report which frequently lead to illegal memory accesses
because an IPL report contains addresses to various data.

Cc: <stable@vger.kernel.org>
Fixes: 99feaa717e ("s390/kexec_file: Create ipl report and pass to next kernel")
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-10 14:37:02 +01:00
Eric Farman
6a6dc14ac8 vfio/ccw: calculate number of IDAWs regardless of format
The idal_nr_words() routine works well for 4K IDAWs, but lost its
ability to handle the old 2K formats with the removal of 31-bit
builds in commit 5a79859ae0 ("s390: remove 31 bit support").

Since there's nothing preventing a guest from generating this IDAW
format, let's re-introduce the math for them and use both when
calculating the number of IDAWs based on the bits specified in
the ORB.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-09 14:34:08 +01:00
Sven Schnelle
fe5e23dd98 s390/diag: use __packed __aligned
Use __packed __aligned instead of __attribute__((packed, aligned(X)));
to match the rest of the file.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-09 14:34:05 +01:00
Sven Schnelle
61f37f63f9 s390/fs3270: split header files
In order to use the fs3270 one would need at least the ioctl definitions
in uapi. Add two new include files in uapi, which contain:

fs3270: ioctl number declarations + returned struct for TUBGETMOD.
raw3270: all the orders, attributes and similar stuff used with 3270
terminals.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-09 14:34:05 +01:00
Sven Schnelle
fbaee7464f s390/tty3270: add support for diag 8c
The current code uses diag210 to infer the 3270 geometry from the
model number when running on z/VM. This doesn't work well as almost
all 3270 software clients report as 3279-2 with a custom resolution.
tty3270 assumes it has a 80x24 terminal connected because of the -2
suffix. Use diag 8c to fetch the realy geometry from z/VM.

Note that this doesn't allow dynamic resizing, i.e. reconnecting to
a z/VM session with a different geometry.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-09 14:33:56 +01:00