Remove the not needed "vm/allocate_pgste" sysctl. It has no effect
anymore. However this is a user space visible change. It shouldn't cause
any problems, however if it does this needs to be partially reverted.
Note that some distributions set
vm/allocate_pgste=1
in one of the various sysctl configuration files. Besides a warning about
the (now) non-existent procfs file this doesn't cause any problems.
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>
Since commit d08d4e7cd6 ("s390/mm: use full 4KB page for 2KB PTE") always
4k page tables are allocated, however there is still some (now) obsolete
code left which deals with switching from 2k to 4k page tables for qemu/kvm
processes.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Remove the not needed code.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
An mm has pgstes only after s390_enable_sie() has been called, while
mm_alloc_pgste() may be always true (e.g. via sysctl setting).
Limit the calls to gmap_unlink() in pte_free_tlb() to those cases
where there might be something to unlink.
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 compiler inlines do_syscall() into __do_syscall(). Therefore do this in
C code as well, since this makes the code easier to understand.
Also adjust and add various unlikely() and likely() annotations.
Furthermore this allows to replace the separate exit_to_user_mode() and
syscall_exit_to_user_mode_work() calls with a combined
syscall_exit_to_user_mode() call which results in slightly better code.
Acked-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>
Implement SPINLOCK_LOCKVAL with an inline assembly, which makes use of the
ALTERNATIVE macro, to read spinlock_lockval from lowcore. Provide an
alternative instruction with a different offset in case lowcore is
relocated.
This replaces sequences of two instructions with one instruction.
Before:
10602a: a7 78 00 00 lhi %r7,0
10602e: a5 8e 00 00 llilh %r8,0
106032: 58 d0 83 ac l %r13,940(%r8)
106036: ba 7d b5 80 cs %r7,%r13,1408(%r11)
After:
10602a: a7 88 00 00 lhi %r8,0
10602e: e3 70 03 ac 00 58 ly %r7,940
106034: ba 87 b5 80 cs %r8,%r7,1408(%r11)
Kernel image size change:
add/remove: 756/750 grow/shrink: 646/3435 up/down: 30778/-46326 (-15548)
Acked-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>
Implement raw_smp_processor_id() with an inline assembly, which makes
use of the ALTERNATIVE macro, to read cpu_nr from lowcore. Provide an
alternative instruction with a different offset in case lowcore is
relocated.
This replaces sequences of two instructions with one instruction.
Before:
1000b6: a5 1e 00 00 llilh %r1,0
1000ba: 58 20 13 a0 l %r2,928(%r1)
After:
1000b6: e3 20 03 a0 00 58 ly %r2,928
Kernel image size change:
add/remove: 753/755 grow/shrink: 230/1510 up/down: 30538/-35832 (-5294)
Acked-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>
Implement current with an inline assembly, which makes use of the
ALTERNATIVE macro, to read current from lowcore. Provide an alternative
instruction with a different offset in case lowcore is relocated.
This replaces sequences of two instructions with one instruction.
Before:
100076: a5 1e 00 00 llilh %r1,0
10007a: e3 40 13 40 00 04 lg %r4,832(%r1)
After:
100076: e3 10 03 40 00 04 lg %r1,832
Kernel image size change:
add/remove: 3/17 grow/shrink: 166/2204 up/down: 7122/-24594 (-17472)
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 asm_inline to let the compiler know that the get_lowcore() inline
assembly has the smallest possible size. The ALTERNATIVE construct is used
to generate a single instruction, however the macro expands to multiple
lines. GCC uses the number of lines of an inline assembly to count the
number of instructions within an inline assembly, which then has an effect
on inlining decisions.
In order to avoid incorrect assumptions use asm_inline. The result is that
more functions are inlined, which results in a small growth of the kernel
image:
add/remove: 59/480 grow/shrink: 854/647 up/down: 168780/-162394 (6386)
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Move s390 sysctls (spin_retry and userprocess_debug) into their own
files under arch/s390. Create two new sysctl tables
(2390_{fault,spin}_sysctl_table) which will be initialized with
arch_initcall placing them after their original place in proc_root_init.
This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kernel/sysctl.c.
Signed-off-by: joel granados <joel.granados@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20250306-jag-mv_ctltables-v2-6-71b243c8d3f8@kernel.org
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
To save/restore LBR call stack data in system-wide mode, the task_struct
information is required.
Extend the parameters of sched_task() to supply task_struct information.
When schedule in, the LBR call stack data for new task will be restored.
When schedule out, the LBR call stack data for old task will be saved.
Only need to pass the required task_struct information.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250314172700.438923-4-kan.liang@linux.intel.com
ioremap_prot() currently accepts pgprot_val parameter as an unsigned long,
thus implicitly assuming that pgprot_val and pgprot_t could never be
bigger than unsigned long. But this assumption soon will not be true on
arm64 when using D128 pgtables. In 128 bit page table configuration,
unsigned long is 64 bit, but pgprot_t is 128 bit.
Passing platform abstracted pgprot_t argument is better as compared to
size based data types. Let's change the parameter to directly pass
pgprot_t like another similar helper generic_ioremap_prot().
Without this change in place, D128 configuration does not work on arm64 as
the top 64 bits gets silently stripped when passing the protection value
to this function.
Link: https://lkml.kernel.org/r/20250218101954.415331-1-anshuman.khandual@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Co-developed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The imperative paradigm used to build vmlinux, extract some info from it
or perform some checks on it, and subsequently modify it again goes
against the declarative paradigm that is usually employed for defining
make rules.
In particular, the Makefile.postlink files that consume their input via
an output rule result in some dodgy logic in the decompressor makefiles
for RISC-V and x86, given that the vmlinux.relocs input file needed to
generate the arch-specific relocation tables may not exist or be out of
date, but cannot be constructed using the ordinary Make dependency based
rules, because the info needs to be extracted while vmlinux is in its
ephemeral, non-stripped form.
So instead, for architectures that require the static relocations that
are emitted into vmlinux when passing --emit-relocs to the linker, and
are subsequently stripped out again, introduce an intermediate vmlinux
target called vmlinux.unstripped, and organize the reset of the build
logic accordingly:
- vmlinux.unstripped is created only once, and not updated again
- build rules under arch/*/boot can depend on vmlinux.unstripped without
running the risk of the data disappearing or being out of date
- the final vmlinux generated by the build is not bloated with static
relocations that are never needed again after the build completes.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Some architectures build vmlinux with static relocations preserved, but
strip them again from the final vmlinux image. Arch specific tools
consume these static relocations in order to construct relocation tables
for KASLR.
The fact that vmlinux is created, consumed and subsequently updated goes
against the typical, declarative paradigm used by Make, which is based
on rules and dependencies. So as a first step towards cleaning this up,
introduce a Kconfig symbol to declare that the arch wants to consume the
static relocations emitted into vmlinux. This will be wired up further
in subsequent patches.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Introduce BPF instructions with load-acquire and store-release
semantics, as discussed in [1]. Define 2 new flags:
#define BPF_LOAD_ACQ 0x100
#define BPF_STORE_REL 0x110
A "load-acquire" is a BPF_STX | BPF_ATOMIC instruction with the 'imm'
field set to BPF_LOAD_ACQ (0x100).
Similarly, a "store-release" is a BPF_STX | BPF_ATOMIC instruction with
the 'imm' field set to BPF_STORE_REL (0x110).
Unlike existing atomic read-modify-write operations that only support
BPF_W (32-bit) and BPF_DW (64-bit) size modifiers, load-acquires and
store-releases also support BPF_B (8-bit) and BPF_H (16-bit). As an
exception, however, 64-bit load-acquires/store-releases are not
supported on 32-bit architectures (to fix a build error reported by the
kernel test robot).
An 8- or 16-bit load-acquire zero-extends the value before writing it to
a 32-bit register, just like ARM64 instruction LDARH and friends.
Similar to existing atomic read-modify-write operations, misaligned
load-acquires/store-releases are not allowed (even if
BPF_F_ANY_ALIGNMENT is set).
As an example, consider the following 64-bit load-acquire BPF
instruction (assuming little-endian):
db 10 00 00 00 01 00 00 r0 = load_acquire((u64 *)(r1 + 0x0))
opcode (0xdb): BPF_ATOMIC | BPF_DW | BPF_STX
imm (0x00000100): BPF_LOAD_ACQ
Similarly, a 16-bit BPF store-release:
cb 21 00 00 10 01 00 00 store_release((u16 *)(r1 + 0x0), w2)
opcode (0xcb): BPF_ATOMIC | BPF_H | BPF_STX
imm (0x00000110): BPF_STORE_REL
In arch/{arm64,s390,x86}/net/bpf_jit_comp.c, have
bpf_jit_supports_insn(..., /*in_arena=*/true) return false for the new
instructions, until the corresponding JIT compiler supports them in
arena.
[1] https://lore.kernel.org/all/20240729183246.4110549-1-yepeilin@google.com/
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Peilin Ye <yepeilin@google.com>
Link: https://lore.kernel.org/r/a217f46f0e445fbd573a1a024be5c6bf1d5fe716.1741049567.git.yepeilin@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Rather than returning the address and storing the length into an
argument pointer, add an address field to the walk struct and use
that to store the address. The length is returned directly.
Change the done functions to use this stored address instead of
getting them from the caller.
Split the address into two using a union. The user should only
access the const version so that it is never changed.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cross-merge networking fixes after downstream PR (net-6.14-rc6).
Conflicts:
tools/testing/selftests/drivers/net/ping.py
75cc19c8ff ("selftests: drv-net: add xdp cases for ping.py")
de94e86974 ("selftests: drv-net: store addresses in dict indexed by ipver")
https://lore.kernel.org/netdev/20250311115758.17a1d414@canb.auug.org.au/
net/core/devmem.c
a70f891e0f ("net: devmem: do not WARN conditionally after netdev_rx_queue_restart()")
1d22d3060b ("net: drop rtnl_lock for queue_mgmt operations")
https://lore.kernel.org/netdev/20250313114929.43744df1@canb.auug.org.au/
Adjacent changes:
tools/testing/selftests/net/Makefile
6f50175cca ("selftests: Add IPv6 link-local address generation tests for GRE devices.")
2e5584e0f9 ("selftests/net: expand cmsg_ipv6.sh with ipv4")
drivers/net/ethernet/broadcom/bnxt/bnxt.c
661958552e ("eth: bnxt: do not use BNXT_VNIC_NTUPLE unconditionally in queue restart logic")
fe96d717d3 ("bnxt_en: Extend queue stop/start for TX rings")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Heiko writes:
"The recent large kernel Rust thread where Linus commented about that
structures may be returned in registers [1] made me again aware that this
is not true for s390 where the ABI defines that structures are returned in
a return value buffer allocated by the caller. This was also mentioned by
Alexander Gordeev a couple of weeks ago.
In theory the -freg-struct-return compiler flag would allow to return small
structures in registers, however that has not been implemented for
s390. Juergen Christ did an experimental gcc implementation which shows the
benefit of such a change (bloat-o-meter):
add/remove: 3/2 grow/shrink: 12/441 up/down: 740/-7182 (-6442)
This result is not very impressive, and doesn't seem to justify a new ABI
for the kernel.
However there is still the existing STRICT_MM_TYPECHECKS which can be used
to change some mm types from structures to simple scalar types. Changing
the mm types results in:
add/remove: 2/8 grow/shrink: 25/116 up/down: 3902/-6204 (-2302)
Which is already a third of the possible savings which would be the result
of the described ABI change.
Therefore add support for a configurable STRICT_MM_TYPECHECKS which allows
to generate better code, but also allows to have type checking for debug
builds."
[1] https://lore.kernel.org/all/CAHk-=wgb1g9VVHRaAnJjrfRFWAOVT2ouNOMqt0js8h3D6zvHDw@mail.gmail.com/
* strict-mm-typechecks-support:
s390/mm: Add configurable STRICT_MM_TYPECHECKS
s390/mm: Convert pgste_val() into function
s390/mm: Convert pgprot_val() into function
s390/mm: Use pgprot_val() instead of open coding
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Replace the while loop and if statement with a simple for loop
to make the code easier to understand.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
It turns out that while s390 architecture calls its memory-I/O mapping
variants write-through and write-back the implementation of ioremap_wt()
and pgprot_writethrough() does not match Linux notion of ioremap_wt().
In particular Linux expects ioremap_wt() to be weaker still than
ioremap_wc(), allowing not just gathering and re-ordering but also reads
to be served from cache. Instead s390's implementation is equivalent to
normal ioremap() while its ioremap_wc() allows re-ordering.
Note that there are no known users of ioremap_wt() on s390 and the
resulting behavior is in line with asm-generic defining ioremap_wt() as
ioremap(), if undefined, so no breakage is expected.
As s390 does not have a mapping type matching the Linux notion of
ioremap_wt() and pgprot_writethrough(), simply drop them and rely on the
asm-generic fallbacks instead.
Fixes: b02002cc4c ("s390/pci: Implement ioremap_wc/prot() with MIO")
Fixes: b43b3fff04 ("s390: mm: convert to GENERIC_IOREMAP")
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Add support for configurable STRICT_MM_TYPECHECKS. The s390 ABI defines
that return values with complex types like structures and unions are
returned in a return value buffer allocated by the caller. This is also
true for small structures and unions which would fit into a register. On
the other hand when such types are passed as arguments to functions they
are passed in registers, if they are small enough.
This leads to inefficient code when such a return value of a function call
is then passed as argument to a subsequent function call.
This is especially true for all mm types, like pte_t and others, which are
only for type checking reasons defined as a structure. This however can be
bypassed with the STRICT_MM_TYPECHECKS feature, which is used by a few
other architectures, which seem to have the same problem.
Add CONFIG_STRICT_MM_TYPECHECKS which can be used to change the type of
pte_t and other structures. If the config option is not enabled the types
are defined to unsigned long, allowing for better code generation, however
there is no type checking anymore. If it is enabled the types are
structures like before so that type checking is performed, but less
efficient code is generated.
The option is always enabled in debug_defconfig, and for convenience an
mmtypes.config topic target is added, which allows to easily enable it, in
case memory management code is changed.
CONFIG_STRICT_MM_TYPECHECKS and STRICT_MM_TYPECHECKS are kept separate,
since STRICT_MM_TYPECHECKS is common across architectures and common
code. Therefore use the same define also for s390 code.
Add CONFIG_STRICT_MM_TYPECHECKS to make it build time configurable.
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>
Similar to all other *_val() functions convert the last remaining
architecture specific mm primitive pgste_val() into a function.
Add set_pgste_bit() and clear_pgste_bit() helper functions which allow to
clear and set pgste bits. This is also similar to e.g. set_pte_bit() and
other helper functions.
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>
Convert pgprot_val() into a function similar to other mm primitives like
e.g. pte_val(). This disallows usage as an lvalue; however there aren't any
such users left, except for some architecture specific ones.
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 pgprot_val() to get the page protection value, instead of accessing the
structure member directly. The type of pgprot_t is supposed to be hidden
from all users so that it can be changed; e.g. for STRICT_MM_TYPECHECKS.
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>
To support multiple PTP clocks, the VDSO data structure needs to be
reworked. All clock specific data will end up in struct vdso_clock and in
struct vdso_time_data there will be an array of VDSO clocks.
Now that all preparatory changes are in place:
Split the clock related struct members into a separate struct
vdso_clock. Make sure all users are aware, that vdso_time_data is no longer
initialized as an array and vdso_clock is now the array inside
vdso_data. Remove the vdso_clock define, which mapped it to vdso_time_data
for the transition.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250303-vdso-clock-v1-19-c1b5c69a166f@linutronix.de
Pull s390 fixes from Vasily Gorbik:
- Fix return address recovery of traced function in ftrace to ensure
reliable stack unwinding
- Fix compiler warnings and runtime crashes of vDSO selftests on s390
by introducing a dedicated GNU hash bucket pointer with correct
32-bit entry size
- Fix test_monitor_call() inline asm, which misses CC clobber, by
switching to an instruction that doesn't modify CC
* tag 's390-6.14-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/ftrace: Fix return address recovery of traced function
selftests/vDSO: Fix GNU hash table entry size for s390x
s390/traps: Fix test_monitor_call() inline assembly
Cross-merge networking fixes after downstream PR (net-6.14-rc6).
Conflicts:
net/ethtool/cabletest.c
2bcf4772e4 ("net: ethtool: try to protect all callback with netdev instance lock")
637399bf7e ("net: ethtool: netlink: Allow NULL nlattrs when getting a phy_device")
No Adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Depending on MARCH_HAS_Z196_FEATURES __atomic_add_const() returns void or
the previous value before the atomic variant. Make sure that for both cases
void is returned so potential incorrect usage results in both cases in a
compile error.
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
When the kernel stack pointer is pointing to invalid memory,
a 'Kernel stack overflow' message is printed, which is misleading.
Change the message to actually say that the stack pointer is invalid
instead.
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>
If the vector facility is installed cpu_has_vx() is always true, if it is
not installed the result is always false, and no vector exception can
happen. Therefore remove the superfluous check.
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>
Use pr_emerg() instead of printk() in case of a stack overflow,
providing the emergency printk level. Also slightly adjust the
printed text for pr_emerg() and panic().
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>
The usage of get_user() in illegal_op() is quite unusual. Make the code
more readable and get rid of unnecessary casts. The generated code is
identical before/after this change.
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>
