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[ Upstream commit 75c10d5377d8821efafed32e4d72068d9c1f8ec0 ]
The .data.rel.ro and .got section were added between the rodata and
ro_after_init data section, which adds an RW mapping in between all RO
mapping of the kernel image:
---[ Kernel Image Start ]---
0x000003ffe0000000-0x000003ffe0e00000 14M PMD RO X
0x000003ffe0e00000-0x000003ffe0ec7000 796K PTE RO X
0x000003ffe0ec7000-0x000003ffe0f00000 228K PTE RO NX
0x000003ffe0f00000-0x000003ffe1300000 4M PMD RO NX
0x000003ffe1300000-0x000003ffe1331000 196K PTE RO NX
0x000003ffe1331000-0x000003ffe13b3000 520K PTE RW NX <---
0x000003ffe13b3000-0x000003ffe13d5000 136K PTE RO NX
0x000003ffe13d5000-0x000003ffe1400000 172K PTE RW NX
0x000003ffe1400000-0x000003ffe1500000 1M PMD RW NX
0x000003ffe1500000-0x000003ffe1700000 2M PTE RW NX
0x000003ffe1700000-0x000003ffe1800000 1M PMD RW NX
0x000003ffe1800000-0x000003ffe187e000 504K PTE RW NX
---[ Kernel Image End ]---
Move the ro_after_init data section again right behind the rodata
section to prevent interleaving RO and RW mappings:
---[ Kernel Image Start ]---
0x000003ffe0000000-0x000003ffe0e00000 14M PMD RO X
0x000003ffe0e00000-0x000003ffe0ec7000 796K PTE RO X
0x000003ffe0ec7000-0x000003ffe0f00000 228K PTE RO NX
0x000003ffe0f00000-0x000003ffe1300000 4M PMD RO NX
0x000003ffe1300000-0x000003ffe1353000 332K PTE RO NX
0x000003ffe1353000-0x000003ffe1400000 692K PTE RW NX
0x000003ffe1400000-0x000003ffe1500000 1M PMD RW NX
0x000003ffe1500000-0x000003ffe1700000 2M PTE RW NX
0x000003ffe1700000-0x000003ffe1800000 1M PMD RW NX
0x000003ffe1800000-0x000003ffe187e000 504K PTE RW NX
---[ Kernel Image End ]---
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 4a1725281fc5b0009944b1c0e1d2c1dc311a09ec ]
Both the external call as well as the emergency signal submask bits in
control register 0 are set before any interrupt handler is registered.
Change the order and first register the interrupt handler and only then
enable the interrupts by setting the corresponding bits in control
register 0.
This prevents that the second part of the machine check handler for
early machine check handling is not executed: the machine check handler
sends an IPI to the CPU it runs on. If the corresponding interrupts are
enabled, but no interrupt handler is present, the interrupt is ignored.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Acked-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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit e6ce1f12d777f6ee22b20e10ae6a771e7e6f44f5 ]
Event CF_DIAG reads out complete counter sets using stcctm
instruction. This is done at event start time when the process
starts execution and at event stop time when the process is
removed from the CPU. During removal the difference of each
counter in the counter sets is calculated and saved as raw data
in the ring buffer. This works fine unless the number of counters
in a counter set is zero. This may happen for the extended counter
set. This set is machine specific and the size of the counter
set can be zero even when extended counter set is authorized for
read access.
This case is not handled. cfdiag_diffctr() checks authorization
of the extended counter set. If true the functions assumes
the extended counter set has been saved in a data buffer. However
this is not the case, cfdiag_getctrset() does not save a counter
set with counter set size of zero. This mismatch causes an endless
loop in the counter set readout during event stop handling.
The calculation of the difference of the counters in each counter
now verifies the size of the counter set is non-zero. A counter set
with size zero is skipped.
Fixes: a029a4eab39e ("s390/cpumf: Allow concurrent access for CPU Measurement Counter Facility")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 3f29f6537f54d74e64bac0a390fb2e26da25800d ]
folio_wait_writeback() requires that no spinlocks are held and that
a folio reference is held, as documented. After we dropped the PTL, the
folio could get freed concurrently. So grab a temporary reference.
Fixes: 214d9bbcd3a6 ("s390/mm: provide memory management functions for protected KVM guests")
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240508182955.358628-2-david@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit d35c34bb32f2cc4ec0b52e91ad7a8fcab55d7856 ]
Remove uses of deprecated page APIs, and move the check for large
folios to here to avoid taking the folio lock if the folio is too large.
We could do better here by attempting to split the large folio, but I'll
leave that improvement for someone who can test it.
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240322161149.2327518-3-willy@infradead.org
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Stable-dep-of: 3f29f6537f54 ("s390/uv: Don't call folio_wait_writeback() without a folio reference")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 259e660d91d0e7261ae0ee37bb37266d6006a546 ]
These page APIs are deprecated, so convert the incoming page to a folio
and use the folio APIs instead. The ultravisor API cannot handle large
folios, so return -EINVAL if one has slipped through.
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240322161149.2327518-2-willy@infradead.org
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Stable-dep-of: 3f29f6537f54 ("s390/uv: Don't call folio_wait_writeback() without a folio reference")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit d3882564a77c21eb746ba5364f3fa89b88de3d61 upstream.
Using sys_io_pgetevents() as the entry point for compat mode tasks
works almost correctly, but misses the sign extension for the min_nr
and nr arguments.
This was addressed on parisc by switching to
compat_sys_io_pgetevents_time64() in commit 6431e92fc827 ("parisc:
io_pgetevents_time64() needs compat syscall in 32-bit compat mode"),
as well as by using more sophisticated system call wrappers on x86 and
s390. However, arm64, mips, powerpc, sparc and riscv still have the
same bug.
Change all of them over to use compat_sys_io_pgetevents_time64()
like parisc already does. This was clearly the intention when the
function was originally added, but it got hooked up incorrectly in
the tables.
Cc: stable@vger.kernel.org
Fixes: 48166e6ea47d ("y2038: add 64-bit time_t syscalls to all 32-bit architectures")
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 1a7d0890dd4a502a202aaec792a6c04e6e049547 ]
If an error happens in ftrace, ftrace_kill() will prevent disarming
kprobes. Eventually, the ftrace_ops associated with the kprobes will be
freed, yet the kprobes will still be active, and when triggered, they
will use the freed memory, likely resulting in a page fault and panic.
This behavior can be reproduced quite easily, by creating a kprobe and
then triggering a ftrace_kill(). For simplicity, we can simulate an
ftrace error with a kernel module like [1]:
[1]: https://github.com/brenns10/kernel_stuff/tree/master/ftrace_killer
sudo perf probe --add commit_creds
sudo perf trace -e probe:commit_creds
# In another terminal
make
sudo insmod ftrace_killer.ko # calls ftrace_kill(), simulating bug
# Back to perf terminal
# ctrl-c
sudo perf probe --del commit_creds
After a short period, a page fault and panic would occur as the kprobe
continues to execute and uses the freed ftrace_ops. While ftrace_kill()
is supposed to be used only in extreme circumstances, it is invoked in
FTRACE_WARN_ON() and so there are many places where an unexpected bug
could be triggered, yet the system may continue operating, possibly
without the administrator noticing. If ftrace_kill() does not panic the
system, then we should do everything we can to continue operating,
rather than leave a ticking time bomb.
Link: https://lore.kernel.org/all/20240501162956.229427-1-stephen.s.brennan@oracle.com/
Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit e7dec0b7926f3cd493c697c4c389df77e8e8a34c ]
It is nowhere used in the decompressor, therefore remove it.
Fixes: 17e89e1340a3 ("s390/facilities: move stfl information from lowcore to global data")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 7faacaeaf6ce12fae78751de5ad869d8f1e1cd7a ]
Initialize the correct fields of the nvme dump block.
This bug had not been detected before because first, the fcp and nvme fields
of struct ipl_parameter_block are part of the same union and, therefore,
overlap in memory and second, they are identical in structure and size.
Fixes: d70e38cb1dee ("s390: nvme dump support")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 9c922b73acaf39f867668d9cbe5dc69c23511f84 ]
Use correct symbolic constants IPL_BP_NVME_LEN and IPL_BP0_NVME_LEN
to initialize nvme reipl block when 'scp_data' sysfs attribute is
being updated. This bug had not been detected before because
the corresponding fcp and nvme symbolic constants are equal.
Fixes: 23a457b8d57d ("s390: nvme reipl")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 185445c7c137822ad856aae91a41e199370cb534 ]
By default user space is compiled with standard stack frame layout and not
with the packed stack layout. The vdso code however inherited the
-mpacked-stack compiler option from the kernel. Remove this option to make
sure the vdso is compiled with standard stack frame layout.
This makes sure that the stack frame backchain location for vdso generated
stack frames is the same like for calling code (if compiled with default
options). This allows to manually walk stack frames without DWARF
information, like the kernel is doing it e.g. with arch_stack_walk_user().
Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO")
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 56769ba4b297a629148eb24d554aef72d1ddfd9e ]
Currently, there is no standard implementation for vdso_install,
leading to various issues:
1. Code duplication
Many architectures duplicate similar code just for copying files
to the install destination.
Some architectures (arm, sparc, x86) create build-id symlinks,
introducing more code duplication.
2. Unintended updates of in-tree build artifacts
The vdso_install rule depends on the vdso files to install.
It may update in-tree build artifacts. This can be problematic,
as explained in commit 19514fc665ff ("arm, kbuild: make
"make install" not depend on vmlinux").
3. Broken code in some architectures
Makefile code is often copied from one architecture to another
without proper adaptation.
'make vdso_install' for parisc does not work.
'make vdso_install' for s390 installs vdso64, but not vdso32.
To address these problems, this commit introduces a generic vdso_install
rule.
Architectures that support vdso_install need to define vdso-install-y
in arch/*/Makefile. vdso-install-y lists the files to install.
For example, arch/x86/Makefile looks like this:
vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg
vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg
vdso-install-$(CONFIG_X86_32) += arch/x86/entry/vdso/vdso32.so.dbg
vdso-install-$(CONFIG_IA32_EMULATION) += arch/x86/entry/vdso/vdso32.so.dbg
These files will be installed to $(MODLIB)/vdso/ with the .dbg suffix,
if exists, stripped away.
vdso-install-y can optionally take the second field after the colon
separator. This is needed because some architectures install a vdso
file as a different base name.
The following is a snippet from arch/arm64/Makefile.
vdso-install-$(CONFIG_COMPAT_VDSO) += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so
This will rename vdso.so.dbg to vdso32.so during installation. If such
architectures change their implementation so that the base names match,
this workaround will go away.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Sven Schnelle <svens@linux.ibm.com> # s390
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Guo Ren <guoren@kernel.org>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Stable-dep-of: fc2f5f10f9bc ("s390/vdso: Create .build-id links for unstripped vdso files")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 10f70525365146046dddcc3d36bfaea2aee0376a ]
GDB fails to unwind vDSO functions with error message "PC not saved",
for instance when stepping through gettimeofday().
Add -fasynchronous-unwind-tables to CFLAGS to generate .eh_frame
DWARF unwind information for the vDSO C modules.
Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO")
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 8192a1b3807510d0ed5be1f8988c08f8d41cced9 ]
Gcc recently implemented an optimization [1] for loading symbols without
explicit alignment, aligning with the IBM Z ELF ABI. This ABI mandates
symbols to reside on a 2-byte boundary, enabling the use of the larl
instruction. However, kernel linker scripts may still generate unaligned
symbols. To address this, a new -munaligned-symbols option has been
introduced [2] in recent gcc versions.
[1] https://gcc.gnu.org/pipermail/gcc-patches/2023-June/622872.html
[2] https://gcc.gnu.org/pipermail/gcc-patches/2023-August/625986.html
However, when -munaligned-symbols is used in vdso code, it leads to the
following compilation error:
`.data.rel.ro.local' referenced in section `.text' of
arch/s390/kernel/vdso64/vdso64_generic.o: defined in discarded section
`.data.rel.ro.local' of arch/s390/kernel/vdso64/vdso64_generic.o
vdso linker script discards .data section to make it lightweight.
However, -munaligned-symbols in vdso object files references literal
pool and accesses _vdso_data. Hence, compile vdso code without
-munaligned-symbols. This means in the future, vdso code should deal
with alignment of newly introduced unaligned linker symbols.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Link: https://lore.kernel.org/r/20240219132734.22881-2-sumanthk@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Stable-dep-of: 10f705253651 ("s390/vdso: Generate unwind information for C modules")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b961ec10b9f9719987470236feb50c967db5a652 ]
The return-address (RA) register r14 is specified as volatile in the
s390x ELF ABI [1]. Nevertheless proper CFI directives must be provided
for an unwinder to restore the return address, if the RA register
value is changed from its value at function entry, as it is the case.
[1]: s390x ELF ABI, https://github.com/IBM/s390x-abi/releases
Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO")
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 378ca2d2ad410a1cd5690d06b46c5e2297f4c8c0 upstream.
Align system call table on 8 bytes. With sys_call_table entry size
of 8 bytes that eliminates the possibility of a system call pointer
crossing cache line boundary.
Cc: stable@kernel.org
Suggested-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 367c50f78451d3bd7ad70bc5c89f9ba6dec46ca9 ]
Current average steal timer calculation produces volatile and inflated
values. The only user of this value is KVM so far and it uses that to
decide whether or not to yield the vCPU which is seeing steal time.
KVM compares average steal timer to a threshold and if the threshold
is past then it does not allow CPU polling and yields it to host, else
it keeps the CPU by polling.
Since KVM's steal time threshold is very low by default (%10) it most
likely is not effected much by the bloated average steal timer values
because the operating region is pretty small. However there might be
new users in the future who might rely on this number. Fix average
steal timer calculation by changing the formula from:
avg_steal_timer = avg_steal_timer / 2 + steal_timer;
to the following:
avg_steal_timer = (avg_steal_timer + steal_timer) / 2;
This ensures that avg_steal_timer is actually a naive average of steal
timer values. It now closely follows steal timer values but of course
in a smoother manner.
Fixes: 152e9b8676c6 ("s390/vtime: steal time exponential moving average")
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit cb0cd4ee11142339f2d47eef6db274290b7a482d ]
With commit 36bbc5b4ffab ("cacheinfo: Allow early detection and population
of cache attributes") the shared cpu list for each cache level higher than
L1 is rebuilt even if the list already has been set up.
This is caused by the removal of the cpumask_empty() check within
cache_shared_cpu_map_setup().
However architectures can enforce that the shared cpu list is not rebuilt
by simply setting cpu_map_populated of the per cpu cache info structure to
true, which is also the fix for this problem.
Before:
$ cat /sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_list
0-7
After:
$ cat /sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_list
1
Fixes: 36bbc5b4ffab ("cacheinfo: Allow early detection and population of cache attributes")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 0628c03934187be33942580e10bb9afcc61adeed ]
'-fPIC' as an option to the linker does not do what it seems like it
should. With ld.bfd, it is treated as '-f PIC', which does not make
sense based on the meaning of '-f':
-f SHLIB, --auxiliary SHLIB Auxiliary filter for shared object symbol table
When building with ld.lld (currently under review in a GitHub pull
request), it just errors out because '-f' means nothing and neither does
'-fPIC':
ld.lld: error: unknown argument '-fPIC'
'-fPIC' was blindly copied from CFLAGS when the vDSO stopped being
linked with '$(CC)', it should not be needed. Remove it to clear up the
build failure with ld.lld.
Fixes: 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO")
Link: https://github.com/llvm/llvm-project/pull/75643
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Link: https://lore.kernel.org/r/20240130-s390-vdso-drop-fpic-from-ldflags-v1-1-094ad104fc55@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 225d09d6e5f3870560665a1829d2db79330b4c58 ]
When the device drivers are initialized, a sysfs directory
is created. This contains many attributes which are allocated with
kzalloc(). Should it fail, the memory for the attributes already
created is freed in attr_event_free(). Its second parameter is number
of attribute elements to delete. This parameter is off by one.
When i. e. the 10th attribute fails to get created, attributes
numbered 0 to 9 should be deleted. Currently only attributes
numbered 0 to 8 are deleted.
Fixes: 39d62336f5c1 ("s390/pai: add support for cryptography counters")
Reported-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 8b13601d19c541158a6e18b278c00ba69ae37829 ]
If the content of the floating point control (fpc) register of a traced
process is modified with the ptrace interface the new value is tested for
validity by temporarily loading it into the fpc register.
This may lead to corruption of the fpc register of the tracing process:
if an interrupt happens while the value is temporarily loaded into the
fpc register, and within interrupt context floating point or vector
registers are used, the current fp/vx registers are saved with
save_fpu_regs() assuming they belong to user space and will be loaded into
fp/vx registers when returning to user space.
test_fp_ctl() restores the original user space fpc register value, however
it will be discarded, when returning to user space.
In result the tracer will incorrectly continue to run with the value that
was supposed to be used for the traced process.
Fix this by saving fpu register contents with save_fpu_regs() before using
test_fp_ctl().
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 673752a839694133a328610fcbc54f3d59ae87f3 ]
Add missing IPL_TYPE_ECKD_DUMP case to ipl_init() creating
ECKD ipl device attribute group similar to IPL_TYPE_ECKD case.
Commit e2d2a2968f2a ("s390/ipl: add eckd dump support") should
have had it from the beginning.
Fixes: e2d2a2968f2a ("s390/ipl: add eckd dump support")
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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Building cert_store.o with W=1 reveals this bug:
CC arch/s390/kernel/cert_store.o
arch/s390/kernel/cert_store.c:443:45: warning: ‘sprintf’ may write a terminating nul past the end of the destination [-Wformat-overflow=]
443 | sprintf(desc + name_len, ":%04u:%08u", vce->vce_hdr.vc_index, cs_token);
| ^
arch/s390/kernel/cert_store.c:443:9: note: ‘sprintf’ output between 15 and 18 bytes into a destination of size 15
443 | sprintf(desc + name_len, ":%04u:%08u", vce->vce_hdr.vc_index, cs_token);
Fix this by using the correct maximum width for each integer component
in both buffer length calculation and format string. Also switch to
using snprintf() to guard against potential future changes to the
integer range of each component.
Fixes: 8cf57d7217c3 ("s390: add support for user-defined certificates")
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Pull kvm updates from Paolo Bonzini:
"ARM:
- Clean up vCPU targets, always returning generic v8 as the preferred
target
- Trap forwarding infrastructure for nested virtualization (used for
traps that are taken from an L2 guest and are needed by the L1
hypervisor)
- FEAT_TLBIRANGE support to only invalidate specific ranges of
addresses when collapsing a table PTE to a block PTE. This avoids
that the guest refills the TLBs again for addresses that aren't
covered by the table PTE.
- Fix vPMU issues related to handling of PMUver.
- Don't unnecessary align non-stack allocations in the EL2 VA space
- Drop HCR_VIRT_EXCP_MASK, which was never used...
- Don't use smp_processor_id() in kvm_arch_vcpu_load(), but the cpu
parameter instead
- Drop redundant call to kvm_set_pfn_accessed() in user_mem_abort()
- Remove prototypes without implementations
RISC-V:
- Zba, Zbs, Zicntr, Zicsr, Zifencei, and Zihpm support for guest
- Added ONE_REG interface for SATP mode
- Added ONE_REG interface to enable/disable multiple ISA extensions
- Improved error codes returned by ONE_REG interfaces
- Added KVM_GET_REG_LIST ioctl() implementation for KVM RISC-V
- Added get-reg-list selftest for KVM RISC-V
s390:
- PV crypto passthrough enablement (Tony, Steffen, Viktor, Janosch)
Allows a PV guest to use crypto cards. Card access is governed by
the firmware and once a crypto queue is "bound" to a PV VM every
other entity (PV or not) looses access until it is not bound
anymore. Enablement is done via flags when creating the PV VM.
- Guest debug fixes (Ilya)
x86:
- Clean up KVM's handling of Intel architectural events
- Intel bugfixes
- Add support for SEV-ES DebugSwap, allowing SEV-ES guests to use
debug registers and generate/handle #DBs
- Clean up LBR virtualization code
- Fix a bug where KVM fails to set the target pCPU during an IRTE
update
- Fix fatal bugs in SEV-ES intrahost migration
- Fix a bug where the recent (architecturally correct) change to
reinject #BP and skip INT3 broke SEV guests (can't decode INT3 to
skip it)
- Retry APIC map recalculation if a vCPU is added/enabled
- Overhaul emergency reboot code to bring SVM up to par with VMX, tie
the "emergency disabling" behavior to KVM actually being loaded,
and move all of the logic within KVM
- Fix user triggerable WARNs in SVM where KVM incorrectly assumes the
TSC ratio MSR cannot diverge from the default when TSC scaling is
disabled up related code
- Add a framework to allow "caching" feature flags so that KVM can
check if the guest can use a feature without needing to search
guest CPUID
- Rip out the ancient MMU_DEBUG crud and replace the useful bits with
CONFIG_KVM_PROVE_MMU
- Fix KVM's handling of !visible guest roots to avoid premature
triple fault injection
- Overhaul KVM's page-track APIs, and KVMGT's usage, to reduce the
API surface that is needed by external users (currently only
KVMGT), and fix a variety of issues in the process
Generic:
- Wrap kvm_{gfn,hva}_range.pte in a union to allow mmu_notifier
events to pass action specific data without needing to constantly
update the main handlers.
- Drop unused function declarations
Selftests:
- Add testcases to x86's sync_regs_test for detecting KVM TOCTOU bugs
- Add support for printf() in guest code and covert all guest asserts
to use printf-based reporting
- Clean up the PMU event filter test and add new testcases
- Include x86 selftests in the KVM x86 MAINTAINERS entry"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (279 commits)
KVM: x86/mmu: Include mmu.h in spte.h
KVM: x86/mmu: Use dummy root, backed by zero page, for !visible guest roots
KVM: x86/mmu: Disallow guest from using !visible slots for page tables
KVM: x86/mmu: Harden TDP MMU iteration against root w/o shadow page
KVM: x86/mmu: Harden new PGD against roots without shadow pages
KVM: x86/mmu: Add helper to convert root hpa to shadow page
drm/i915/gvt: Drop final dependencies on KVM internal details
KVM: x86/mmu: Handle KVM bookkeeping in page-track APIs, not callers
KVM: x86/mmu: Drop @slot param from exported/external page-track APIs
KVM: x86/mmu: Bug the VM if write-tracking is used but not enabled
KVM: x86/mmu: Assert that correct locks are held for page write-tracking
KVM: x86/mmu: Rename page-track APIs to reflect the new reality
KVM: x86/mmu: Drop infrastructure for multiple page-track modes
KVM: x86/mmu: Use page-track notifiers iff there are external users
KVM: x86/mmu: Move KVM-only page-track declarations to internal header
KVM: x86: Remove the unused page-track hook track_flush_slot()
drm/i915/gvt: switch from ->track_flush_slot() to ->track_remove_region()
KVM: x86: Add a new page-track hook to handle memslot deletion
drm/i915/gvt: Don't bother removing write-protection on to-be-deleted slot
KVM: x86: Reject memslot MOVE operations if KVMGT is attached
...
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https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
- PV crypto passthrough enablement (Tony, Steffen, Viktor, Janosch)
Allows a PV guest to use crypto cards. Card access is governed by
the firmware and once a crypto queue is "bound" to a PV VM every
other entity (PV or not) looses access until it is not bound
anymore. Enablement is done via flags when creating the PV VM.
- Guest debug fixes (Ilya)
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For consistencs reasons change the type of __samode31, __eamode31,
__stext_amode31, and __etext_amode31 to a char pointer so they
(nearly) match the type of all other sections.
This allows for code simplifications with follow-on patches.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The kernel mapping is setup in two stages: in the decompressor map all
pages with RWX permissions, and within the kernel change all mappings to
their final permissions, where most of the mappings are changed from RWX to
RWNX.
Change this and map all pages RWNX from the beginning, however without
enabling noexec via control register modification. This means that
effectively all pages are used with RWX permissions like before. When the
final permissions have been applied to the kernel mapping enable noexec via
control register modification.
This allows to remove quite a bit of non-obvious code.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Do the same like x86 with commit 76ea0025a214 ("x86/cpu: Remove "noexec"")
and remove the "noexec" kernel command line option.
Reviewed-by: Alexander Gordeev <agordeev@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:
- Add vfio-ap support to pass-through crypto devices to secure
execution guests
- Add API ordinal 6 support to zcrypt_ep11misc device drive, which is
required to handle key generate and key derive (e.g. secure key to
protected key) correctly
- Add missing secure/has_secure sysfs files for the case where it is
not possible to figure where a system has been booted from. Existing
user space relies on that these files are always present
- Fix DCSS block device driver list corruption, caused by incorrect
error handling
- Convert virt_to_pfn() and pfn_to_virt() from defines to static inline
functions to enforce type checking
- Cleanups, improvements, and minor fixes to the kernel mapping setup
- Fix various virtual vs physical address confusions
- Move pfault code to separate file, since it has nothing to do with
regular fault handling
- Move s390 documentation to Documentation/arch/ like it has been done
for other architectures already
- Add HAVE_FUNCTION_GRAPH_RETVAL support
- Factor out the s390_hypfs filesystem and add a new config option for
it. The filesystem is deprecated and as soon as all users are gone it
can be removed some time in the not so near future
- Remove support for old CEX2 and CEX3 crypto cards from zcrypt device
driver
- Add support for user-defined certificates: receive user-defined
certificates with a diagnose call and provide them via 'cert_store'
keyring to user space
- Couple of other small fixes and improvements all over the place
* tag 's390-6.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (66 commits)
s390/pci: use builtin_misc_device macro to simplify the code
s390/vfio-ap: make sure nib is shared
KVM: s390: export kvm_s390_pv*_is_protected functions
s390/uv: export uv_pin_shared for direct usage
s390/vfio-ap: check for TAPQ response codes 0x35 and 0x36
s390/vfio-ap: handle queue state change in progress on reset
s390/vfio-ap: use work struct to verify queue reset
s390/vfio-ap: store entire AP queue status word with the queue object
s390/vfio-ap: remove upper limit on wait for queue reset to complete
s390/vfio-ap: allow deconfigured queue to be passed through to a guest
s390/vfio-ap: wait for response code 05 to clear on queue reset
s390/vfio-ap: clean up irq resources if possible
s390/vfio-ap: no need to check the 'E' and 'I' bits in APQSW after TAPQ
s390/ipl: refactor deprecated strncpy
s390/ipl: fix virtual vs physical address confusion
s390/zcrypt_ep11misc: support API ordinal 6 with empty pin-blob
s390/paes: fix PKEY_TYPE_EP11_AES handling for secure keyblobs
s390/pkey: fix PKEY_TYPE_EP11_AES handling for sysfs attributes
s390/pkey: fix PKEY_TYPE_EP11_AES handling in PKEY_VERIFYKEY2 IOCTL
s390/pkey: fix PKEY_TYPE_EP11_AES handling in PKEY_KBLOB2PROTK[23]
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull fchmodat2 system call from Christian Brauner:
"This adds the fchmodat2() system call. It is a revised version of the
fchmodat() system call, adding a missing flag argument. Support for
both AT_SYMLINK_NOFOLLOW and AT_EMPTY_PATH are included.
Adding this system call revision has been a longstanding request but
so far has always fallen through the cracks. While the kernel
implementation of fchmodat() does not have a flag argument the libc
provided POSIX-compliant fchmodat(3) version does. Both glibc and musl
have to implement a workaround in order to support AT_SYMLINK_NOFOLLOW
(see [1] and [2]).
The workaround is brittle because it relies not just on O_PATH and
O_NOFOLLOW semantics and procfs magic links but also on our rather
inconsistent symlink semantics.
This gives userspace a proper fchmodat2() system call that libcs can
use to properly implement fchmodat(3) and allows them to get rid of
their hacks. In this case it will immediately benefit them as the
current workaround is already defunct because of aformentioned
inconsistencies.
In addition to AT_SYMLINK_NOFOLLOW, give userspace the ability to use
AT_EMPTY_PATH with fchmodat2(). This is already possible with
fchownat() so there's no reason to not also support it for
fchmodat2().
The implementation is simple and comes with selftests. Implementation
of the system call and wiring up the system call are done as separate
patches even though they could arguably be one patch. But in case
there are merge conflicts from other system call additions it can be
beneficial to have separate patches"
Link: https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/fchmodat.c;h=17eca54051ee28ba1ec3f9aed170a62630959143;hb=a492b1e5ef7ab50c6fdd4e4e9879ea5569ab0a6c#l35 [1]
Link: https://git.musl-libc.org/cgit/musl/tree/src/stat/fchmodat.c?id=718f363bc2067b6487900eddc9180c84e7739f80#n28 [2]
* tag 'v6.6-vfs.fchmodat2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
selftests: fchmodat2: remove duplicate unneeded defines
fchmodat2: add support for AT_EMPTY_PATH
selftests: Add fchmodat2 selftest
arch: Register fchmodat2, usually as syscall 452
fs: Add fchmodat2()
Non-functional cleanup of a "__user * filename"
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Introduces a function to check the existence of an UV feature.
Refactor feature bit checks to use the new function.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Michael Mueller <mimu@linux.ibm.com>
Link: https://lore.kernel.org/r/20230815151415.379760-3-seiden@linux.ibm.com
Message-Id: <20230815151415.379760-3-seiden@linux.ibm.com>
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Tony Krowiak says:
===================
This patch series is for the changes required in the vfio_ap device
driver to facilitate pass-through of crypto devices to a secure
execution guest. In particular, it is critical that no data from the
queues passed through to the SE guest is leaked when the guest is
destroyed. There are also some new response codes returned from the
PQAP(ZAPQ) and PQAP(TAPQ) commands that have been added to the
architecture in support of pass-through of crypto devices to SE guests;
these need to be accounted for when handling the reset of queues.
===================
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Export the uv_pin_shared function so that it can be called from other
modules that carry a GPL-compatible license.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Tested-by: Viktor Mihajlovski <mihajlov@linux.ibm.com>
Link: https://lore.kernel.org/r/20230815184333.6554-11-akrowiak@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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`strncpy` is deprecated for use on NUL-terminated destination strings [1].
Use `strscpy` which has the same behavior as `strncpy` here with the
extra safeguard of guaranteeing NUL-termination of destination
strings. In it's current form, this may result in silent truncation
if the src string has the same size as the destination string.
[hca@linux.ibm.com: use strscpy() instead of strscpy_pad()]
Link: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings[1]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20230811-arch-s390-kernel-v1-1-7edbeeab3809@google.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The value of ipl_cert_list_addr boot variable contains
a physical address, which is used directly. That works
because virtual and physical address spaces are currently
the same, but otherwise it is wrong.
While at it, fix also a comment for the platform keyring.
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lore.kernel.org/r/20230816132942.2540411-1-agordeev@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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All ipl types have 'secure','has_secure' and type parameters. Move
these to a common ipl parameter group so that they don't need to be
present in each ipl parameter group.
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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OS installers are relying on /sys/firmware/ipl/has_secure to be
present on machines supporting secure boot. This file is present
for all IPL types, but not the unknown type, which prevents a secure
installation when an LPAR is booted in HMC via FTP(s), because
this is an unknown IPL type in linux. While at it, also add the secure
file.
Fixes: c9896acc7851 ("s390/ipl: Provide has_secure sysfs attribute")
Cc: stable@vger.kernel.org
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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Commit ddb5cdbafaaa ("kbuild: generate KSYMTAB entries by modpost")
deprecated <asm/export.h>, which is now a wrapper of <linux/export.h>.
Replace #include <asm/export.h> with #include <linux/export.h>.
After all the <asm/export.h> lines are converted, <asm/export.h> and
<asm-generic/export.h> will be removed.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20230806151641.394720-2-masahiroy@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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There is no EXPORT_SYMBOL line there, hence #include <asm/export.h>
is unneeded.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20230806151641.394720-1-masahiroy@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Globally setting a bit in control registers is done with
smp_ctl_set_clear_bit(). This is using on_each_cpu() to execute a function
which actually sets the control register bit on each online CPU. This can
be problematic since on_each_cpu() does not prevent that new CPUs come
online while it is executed, which in turn means that control register
updates could be missing on new CPUs.
In order to prevent this problem make sure that global control register
contents cannot change until new CPUs have initialized their control
registers, and marked themselves online, so they are included in subsequent
on_each_cpu() calls.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The 'rc' will be re-assigned to 0 after calling get_vcssb(), it
needs be set to error code if create_cs_keyring() fails.
[hca@linux.ibm.com: slightly changed coding style]
Fixes: 8cf57d7217c3 ("s390: add support for user-defined certificates")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20230728084228.3186083-1-yangyingliang@huawei.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The pfault code has nothing to do with regular fault handling.
Therefore move it to an own C file. Also add an own pfault header
file. This way changes to setup.h don't cause a recompile of the
pfault code and vice versa.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Commit 9fb6c9b3fea1 ("s390/sthyi: add cache to store hypervisor info")
added cache handling for store hypervisor info. This also changed the
possible return code for sthyi_fill().
Instead of only returning a condition code like the sthyi instruction would
do, it can now also return a negative error value (-ENOMEM). handle_styhi()
was not changed accordingly. In case of an error, the negative error value
would incorrectly injected into the guest PSW.
Add proper error handling to prevent this, and update the comment which
describes the possible return values of sthyi_fill().
Fixes: 9fb6c9b3fea1 ("s390/sthyi: add cache to store hypervisor info")
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Link: https://lore.kernel.org/r/20230727182939.2050744-1-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Nathan Chancellor reported the following build error when compiling the
kernel with CONFIG_MARCH_Z10=y:
arch/s390/kernel/mcount.S: Assembler messages:
arch/s390/kernel/mcount.S:140: Error: Unrecognized opcode: `aghik'
The aghik instruction is only available since z196. Use the la instruction
instead which is available for all machines.
Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/all/20230725211105.GA224840@dev-arch.thelio-3990X
Fixes: 1256e70a082a ("s390/ftrace: enable HAVE_FUNCTION_GRAPH_RETVAL")
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Tested-by: Nathan Chancellor <nathan@kernel.org> # build
Link: https://lore.kernel.org/r/20230726061834.1300984-1-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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s/ECBDIC/EBCDIC/ (C and B are swapped)
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/08ed63331699177b3354458da66a2f63c0217e49.1686407113.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The comment above diag8c() describes diagnose 210, not diagnose 8c.
Add a proper short description.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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This registers the new fchmodat2 syscall in most places as nuber 452,
with alpha being the exception where it's 562. I found all these sites
by grepping for fspick, which I assume has found me everything.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Message-Id: <a677d521f048e4ca439e7080a5328f21eb8e960e.1689092120.git.legion@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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ftrace_trace_function expects a struct ftrace_regs, but the s390
architecure code passes struct pt_regs. This isn't a problem with the
current code because struct ftrace_regs contains only one member:
struct pt_regs. To avoid issues in the future this should be fixed.
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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As per description in mm/memory_hotplug.c platforms should define
arch_get_mappable_range() that provides maximum possible addressable
physical memory range for which the linear mapping could be created.
The current implementation uses VMEM_MAX_PHYS macro as the maximum
mappable physical address and it is simply a cast to vmemmap. Since
the address is in physical address space the natural upper limit of
MAX_PHYSMEM_BITS is honoured:
vmemmap_start = min(vmemmap_start, 1UL << MAX_PHYSMEM_BITS);
Further, to make sure the identity mapping would not overlay with
vmemmap, the size of identity mapping could be stripped like this:
ident_map_size = min(ident_map_size, vmemmap_start);
Similarily, any other memory that could be added (e.g DCSS segment)
should not overlay with vmemmap as well and that is prevented by
using vmemmap (VMEM_MAX_PHYS macro) as the upper limit.
However, while the use of VMEM_MAX_PHYS brings the desired result
it actually poses two issues:
1. As described, vmemmap is handled as a physical address, although
it is actually a pointer to struct page in virtual address space.
2. As vmemmap is a virtual address it could have been located
anywhere in the virtual address space. However, the desired
necessity to honour MAX_PHYSMEM_BITS limit prevents that.
Rework arch_get_mappable_range() callback in a way it does not
use VMEM_MAX_PHYS macro and does not confuse the notion of virtual
vs physical address spacees as result. That paves the way for moving
vmemmap elsewhere and optimizing the virtual address space layout.
Introduce max_mappable preserved boot variable and let function
setup_kernel_memory_layout() set it up. As result, the rest of the
code is does not need to know the virtual memory layout specifics.
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>
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