Commit aa47a7c215 ("lib/cpumask: deprecate nr_cpumask_bits") resulted
in the cpumask operations potentially becoming hugely less efficient,
because suddenly the cpumask was always considered to be variable-sized.
The optimization was then later added back in a limited form by commit
6f9c07be9d ("lib/cpumask: add FORCE_NR_CPUS config option"), but that
FORCE_NR_CPUS option is not useful in a generic kernel and more of a
special case for embedded situations with fixed hardware.
Instead, just re-introduce the optimization, with some changes.
Instead of depending on CPUMASK_OFFSTACK being false, and then always
using the full constant cpumask width, this introduces three different
cpumask "sizes":
- the exact size (nr_cpumask_bits) remains identical to nr_cpu_ids.
This is used for situations where we should use the exact size.
- the "small" size (small_cpumask_bits) is the NR_CPUS constant if it
fits in a single word and the bitmap operations thus end up able
to trigger the "small_const_nbits()" optimizations.
This is used for the operations that have optimized single-word
cases that get inlined, notably the bit find and scanning functions.
- the "large" size (large_cpumask_bits) is the NR_CPUS constant if it
is an sufficiently small constant that makes simple "copy" and
"clear" operations more efficient.
This is arbitrarily set at four words or less.
As a an example of this situation, without this fixed size optimization,
cpumask_clear() will generate code like
movl nr_cpu_ids(%rip), %edx
addq $63, %rdx
shrq $3, %rdx
andl $-8, %edx
callq memset@PLT
on x86-64, because it would calculate the "exact" number of longwords
that need to be cleared.
In contrast, with this patch, using a MAX_CPU of 64 (which is quite a
reasonable value to use), the above becomes a single
movq $0,cpumask
instruction instead, because instead of caring to figure out exactly how
many CPU's the system has, it just knows that the cpumask will be a
single word and can just clear it all.
Note that this does end up tightening the rules a bit from the original
version in another way: operations that set bits in the cpumask are now
limited to the actual nr_cpu_ids limit, whereas we used to do the
nr_cpumask_bits thing almost everywhere in the cpumask code.
But if you just clear bits, or scan for bits, we can use the simpler
compile-time constants.
In the process, remove 'cpumask_complement()' and 'for_each_cpu_not()'
which were not useful, and which fundamentally have to be limited to
'nr_cpu_ids'. Better remove them now than have somebody introduce use
of them later.
Of course, on x86-64 with MAXSMP there is no sane small compile-time
constant for the cpumask sizes, and we end up using the actual CPU bits,
and will generate the above kind of horrors regardless. Please don't
use MAXSMP unless you really expect to have machines with thousands of
cores.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 updates from Thomas Gleixner:
"A small set of updates for x86:
- Return -EIO instead of success when the certificate buffer for SEV
guests is not large enough
- Allow STIPB to be enabled with legacy IBSR. Legacy IBRS is cleared
on return to userspace for performance reasons, but the leaves user
space vulnerable to cross-thread attacks which STIBP prevents.
Update the documentation accordingly"
* tag 'x86-urgent-2023-03-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
virt/sev-guest: Return -EIO if certificate buffer is not large enough
Documentation/hw-vuln: Document the interaction between IBRS and STIBP
x86/speculation: Allow enabling STIBP with legacy IBRS
Pull VM_FAULT_RETRY fixes from Al Viro:
"Some of the page fault handlers do not deal with the following case
correctly:
- handle_mm_fault() has returned VM_FAULT_RETRY
- there is a pending fatal signal
- fault had happened in kernel mode
Correct action in such case is not "return unconditionally" - fatal
signals are handled only upon return to userland and something like
copy_to_user() would end up retrying the faulting instruction and
triggering the same fault again and again.
What we need to do in such case is to make the caller to treat that as
failed uaccess attempt - handle exception if there is an exception
handler for faulting instruction or oops if there isn't one.
Over the years some architectures had been fixed and now are handling
that case properly; some still do not. This series should fix the
remaining ones.
Status:
- m68k, riscv, hexagon, parisc: tested/acked by maintainers.
- alpha, sparc32, sparc64: tested locally - bug has been reproduced
on the unpatched kernel and verified to be fixed by this series.
- ia64, microblaze, nios2, openrisc: build, but otherwise completely
untested"
* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
openrisc: fix livelock in uaccess
nios2: fix livelock in uaccess
microblaze: fix livelock in uaccess
ia64: fix livelock in uaccess
sparc: fix livelock in uaccess
alpha: fix livelock in uaccess
parisc: fix livelock in uaccess
hexagon: fix livelock in uaccess
riscv: fix livelock in uaccess
m68k: fix livelock in uaccess
include/linux/compiler-intel.h had no update in the past 3 years.
We often forget about the third C compiler to build the kernel.
For example, commit a0a12c3ed0 ("asm goto: eradicate CC_HAS_ASM_GOTO")
only mentioned GCC and Clang.
init/Kconfig defines CC_IS_GCC and CC_IS_CLANG but not CC_IS_ICC,
and nobody has reported any issue.
I guess the Intel Compiler support is broken, and nobody is caring
about it.
Harald Arnesen pointed out ICC (classic Intel C/C++ compiler) is
deprecated:
$ icc -v
icc: remark #10441: The Intel(R) C++ Compiler Classic (ICC) is
deprecated and will be removed from product release in the second half
of 2023. The Intel(R) oneAPI DPC++/C++ Compiler (ICX) is the recommended
compiler moving forward. Please transition to use this compiler. Use
'-diag-disable=10441' to disable this message.
icc version 2021.7.0 (gcc version 12.1.0 compatibility)
Arnd Bergmann provided a link to the article, "Intel C/C++ compilers
complete adoption of LLVM".
lib/zstd/common/compiler.h and lib/zstd/compress/zstd_fast.c were kept
untouched for better sync with https://github.com/facebook/zstd
Link: https://www.intel.com/content/www/us/en/developer/articles/technical/adoption-of-llvm-complete-icx.html
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull misc fixes from Andrew Morton:
"17 hotfixes.
Eight are for MM and seven are for other parts of the kernel. Seven
are cc:stable and eight address post-6.3 issues or were judged
unsuitable for -stable backporting"
* tag 'mm-hotfixes-stable-2023-03-04-13-12' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mailmap: map Dikshita Agarwal's old address to his current one
mailmap: map Vikash Garodia's old address to his current one
fs/cramfs/inode.c: initialize file_ra_state
fs: hfsplus: fix UAF issue in hfsplus_put_super
panic: fix the panic_print NMI backtrace setting
lib: parser: update documentation for match_NUMBER functions
kasan, x86: don't rename memintrinsics in uninstrumented files
kasan: test: fix test for new meminstrinsic instrumentation
kasan: treat meminstrinsic as builtins in uninstrumented files
kasan: emit different calls for instrumentable memintrinsics
ocfs2: fix non-auto defrag path not working issue
ocfs2: fix defrag path triggering jbd2 ASSERT
mailmap: map Georgi Djakov's old Linaro address to his current one
mm/hwpoison: convert TTU_IGNORE_HWPOISON to TTU_HWPOISON
lib/zlib: DFLTCC deflate does not write all available bits for Z_NO_FLUSH
mm/damon/paddr: fix missing folio_put()
mm/mremap: fix dup_anon_vma() in vma_merge() case 4
Pull powerpc fixes from Michael Ellerman:
- Drop orphaned VAS MAINTAINERS entry
- Fix build errors with clang and KCSAN
- Avoid build errors seen with LD_DEAD_CODE_DATA_ELIMINATION together
with recordmcount
Thanks to Nathan Chancellor.
* tag 'powerpc-6.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc: Avoid dead code/data elimination when using recordmcount
powerpc/vmlinux.lds: Add .text.asan/tsan sections
powerpc: Drop orphaned VAS MAINTAINERS entry
Pull more s390 updates from Heiko Carstens:
- Add empty command line parameter handling stubs to kernel for all
command line parameters which are handled in the decompressor. This
avoids invalid "Unknown kernel command line parameters" messages from
the kernel, and also avoids that these will be incorrectly passed to
user space. This caused already confusion, therefore add the empty
stubs
- Add missing phys_to_virt() handling to machine check handler
- Introduce and use a union to be used for zcrypt inline assemblies.
This makes sure that only a register wide member of the union is
passed as input and output parameter to inline assemblies, while
usual C code uses other members of the union to access bit fields of
it
- Add and use a READ_ONCE_ALIGNED_128() macro, which can be used to
atomically read a 128-bit value from memory. This replaces the
(mis-)use of the 128-bit cmpxchg operation to do the same in cpum_sf
code. Currently gcc does not generate the used lpq instruction if
__READ_ONCE() is used for aligned 128-bit accesses, therefore use
this s390 specific helper
- Simplify machine check handler code if a task needs to be killed
because of e.g. register corruption due to a machine malfunction
- Perform CPU reset to clear pending interrupts and TLB entries on an
already stopped target CPU before delegating work to it
- Generate arch/s390/boot/vmlinux.map link map for the decompressor,
when CONFIG_VMLINUX_MAP is enabled for debugging purposes
- Fix segment type handling for dcssblk devices. It incorrectly always
returned type "READ/WRITE" even for read-only segements, which can
result in a kernel panic if somebody tries to write to a read-only
device
- Sort config S390 select list again
- Fix two kprobe reenter bugs revealed by a recently added kprobe kunit
test
* tag 's390-6.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/kprobes: fix current_kprobe never cleared after kprobes reenter
s390/kprobes: fix irq mask clobbering on kprobe reenter from post_handler
s390/Kconfig: sort config S390 select list again
s390/extmem: return correct segment type in __segment_load()
s390/decompressor: add link map saving
s390/smp: perform cpu reset before delegating work to target cpu
s390/mcck: cleanup user process termination path
s390/cpum_sf: use READ_ONCE_ALIGNED_128() instead of 128-bit cmpxchg
s390/rwonce: add READ_ONCE_ALIGNED_128() macro
s390/ap,zcrypt,vfio: introduce and use ap_queue_status_reg union
s390/nmi: fix virtual-physical address confusion
s390/setup: do not complain about parameters handled in decompressor
Pull more RISC-V updates from Palmer Dabbelt:
- Some cleanups and fixes for the Zbb-optimized string routines
- Support for custom (vendor or implementation defined) perf events
- COMMAND_LINE_SIZE has been increased to 1024
* tag 'riscv-for-linus-6.3-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: Bump COMMAND_LINE_SIZE value to 1024
drivers/perf: RISC-V: Allow programming custom firmware events
riscv, lib: Fix Zbb strncmp
RISC-V: improve string-function assembly
Pull arm64 fixes from Catalin Marinas:
- In copy_highpage(), only reset the tag of the destination pointer if
KASAN_HW_TAGS is enabled so that user-space MTE does not interfere
with KASAN_SW_TAGS (which relies on top-byte-ignore).
- Remove warning if SME is detected without SVE, the kernel can cope
with such configuration (though none in the field currently).
- In cfi_handler(), pass the ESR_EL1 value to die() for consistency
with other die() callers.
- Disable HUGETLB_PAGE_OPTIMIZE_VMEMMAP on arm64 since the pte
manipulation from the generic vmemmap_remap_pte() does not follow the
required ARM break-before-make sequence (clear the pte, flush the
TLBs, set the new pte). It may be re-enabled once this sequence is
sorted.
- Fix possible memory leak in the arm64 ACPI code if the SMCCC version
and conduit checks fail.
- Forbid CALL_OPS with CC_OPTIMIZE_FOR_SIZE since gcc ignores
-falign-functions=N with -Os.
- Don't pretend KASLR is enabled if offset < MIN_KIMG_ALIGN as no
randomisation would actually take place.
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: kaslr: don't pretend KASLR is enabled if offset < MIN_KIMG_ALIGN
arm64: ftrace: forbid CALL_OPS with CC_OPTIMIZE_FOR_SIZE
arm64: acpi: Fix possible memory leak of ffh_ctxt
arm64: mm: hugetlb: Disable HUGETLB_PAGE_OPTIMIZE_VMEMMAP
arm64: pass ESR_ELx to die() of cfi_handler
arm64/fpsimd: Remove warning for SME without SVE
arm64: Reset KASAN tag in copy_highpage with HW tags only
Pull more MIPS updates from Thomas Bogendoerfer:
"A few more cleanups and fixes"
* tag 'mips_6.3_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MIPS: Workaround clang inline compat branch issue
mips: dts: ralink: mt7621: add phandle to system controller node for watchdog
mips: dts: ralink: mt7621: rename watchdog node from 'wdt' into 'watchdog'
mips: ralink: make SOC_MT7621 select PINCTRL
mips: remove SYS_HAS_CPU_MIPS32_R1 from RALINK
MIPS: cevt-r4k: Offset the value used to clear compare interrupt
MIPS: smp-cps: Don't rely on CP0_CMGCRBASE
MIPS: Remove DMA_PERDEV_COHERENT
Pull objtool updates from Ingo Molnar:
- Shrink 'struct instruction', to improve objtool performance & memory
footprint
- Other maximum memory usage reductions - this makes the build both
faster, and fixes kernel build OOM failures on allyesconfig and
similar configs when they try to build the final (large) vmlinux.o
- Fix ORC unwinding when a kprobe (INT3) is set on a stack-modifying
single-byte instruction (PUSH/POP or LEAVE). This requires the
extension of the ORC metadata structure with a 'signal' field
- Misc fixes & cleanups
* tag 'objtool-core-2023-03-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
objtool: Fix ORC 'signal' propagation
objtool: Remove instruction::list
x86: Fix FILL_RETURN_BUFFER
objtool: Fix overlapping alternatives
objtool: Union instruction::{call_dest,jump_table}
objtool: Remove instruction::reloc
objtool: Shrink instruction::{type,visited}
objtool: Make instruction::alts a single-linked list
objtool: Make instruction::stack_ops a single-linked list
objtool: Change arch_decode_instruction() signature
x86/entry: Fix unwinding from kprobe on PUSH/POP instruction
x86/unwind/orc: Add 'signal' field to ORC metadata
objtool: Optimize layout of struct special_alt
objtool: Optimize layout of struct symbol
objtool: Allocate multiple structures with calloc()
objtool: Make struct check_options static
objtool: Make struct entries[] static and const
objtool: Fix HOSTCC flag usage
objtool: Properly support make V=1
objtool: Install libsubcmd in build
...
openrisc equivalent of 26178ec11e "x86: mm: consolidate VM_FAULT_RETRY handling"
If e.g. get_user() triggers a page fault and a fatal signal is caught, we might
end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing anything
to page tables. In such case we must *not* return to the faulting insn -
that would repeat the entire thing without making any progress; what we need
instead is to treat that as failed (user) memory access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
nios2 equivalent of 26178ec11e "x86: mm: consolidate VM_FAULT_RETRY handling"
If e.g. get_user() triggers a page fault and a fatal signal is caught, we might
end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing anything
to page tables. In such case we must *not* return to the faulting insn -
that would repeat the entire thing without making any progress; what we need
instead is to treat that as failed (user) memory access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
microblaze equivalent of 26178ec11e "x86: mm: consolidate VM_FAULT_RETRY handling"
If e.g. get_user() triggers a page fault and a fatal signal is caught, we might
end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing anything
to page tables. In such case we must *not* return to the faulting insn -
that would repeat the entire thing without making any progress; what we need
instead is to treat that as failed (user) memory access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
ia64 equivalent of 26178ec11e "x86: mm: consolidate VM_FAULT_RETRY handling"
If e.g. get_user() triggers a page fault and a fatal signal is caught, we might
end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing anything
to page tables. In such case we must *not* return to the faulting insn -
that would repeat the entire thing without making any progress; what we need
instead is to treat that as failed (user) memory access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
sparc equivalent of 26178ec11e "x86: mm: consolidate VM_FAULT_RETRY handling"
If e.g. get_user() triggers a page fault and a fatal signal is caught, we might
end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing anything
to page tables. In such case we must *not* return to the faulting insn -
that would repeat the entire thing without making any progress; what we need
instead is to treat that as failed (user) memory access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
alpha equivalent of 26178ec11e "x86: mm: consolidate VM_FAULT_RETRY handling"
If e.g. get_user() triggers a page fault and a fatal signal is caught, we might
end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing anything
to page tables. In such case we must *not* return to the faulting insn -
that would repeat the entire thing without making any progress; what we need
instead is to treat that as failed (user) memory access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
parisc equivalent of 26178ec11e "x86: mm: consolidate VM_FAULT_RETRY handling"
If e.g. get_user() triggers a page fault and a fatal signal is caught, we might
end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing anything
to page tables. In such case we must *not* return to the faulting insn -
that would repeat the entire thing without making any progress; what we need
instead is to treat that as failed (user) memory access.
Tested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
hexagon equivalent of 26178ec11e "x86: mm: consolidate VM_FAULT_RETRY handling"
If e.g. get_user() triggers a page fault and a fatal signal is caught, we might
end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing anything
to page tables. In such case we must *not* return to the faulting insn -
that would repeat the entire thing without making any progress; what we need
instead is to treat that as failed (user) memory access.
Acked-by: Brian Cain <bcain@quicinc.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
riscv equivalent of 26178ec11e "x86: mm: consolidate VM_FAULT_RETRY handling"
If e.g. get_user() triggers a page fault and a fatal signal is caught, we might
end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing anything
to page tables. In such case we must *not* return to the faulting insn -
that would repeat the entire thing without making any progress; what we need
instead is to treat that as failed (user) memory access.
Tested-by: Björn Töpel <bjorn@kernel.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
m68k equivalent of 26178ec11e "x86: mm: consolidate VM_FAULT_RETRY handling"
If e.g. get_user() triggers a page fault and a fatal signal is caught, we might
end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing anything
to page tables. In such case we must *not* return to the faulting insn -
that would repeat the entire thing without making any progress; what we need
instead is to treat that as failed (user) memory access.
Tested-by: Finn Thain <fthain@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Recent test_kprobe_missed kprobes kunit test uncovers the following
problem. Once kprobe is triggered from another kprobe (kprobe reenter),
all future kprobes on this cpu are considered as kprobe reenter, thus
pre_handler and post_handler are not being called and kprobes are counted
as "missed".
Commit b9599798f9 ("[S390] kprobes: activation and deactivation")
introduced a simpler scheme for kprobes (de)activation and status
tracking by using push_kprobe/pop_kprobe, which supposed to work for
both initial kprobe entry as well as kprobe reentry and helps to avoid
handling those two cases differently. The problem is that a sequence of
calls in case of kprobes reenter:
push_kprobe() <- NULL (current_kprobe)
push_kprobe() <- kprobe1 (current_kprobe)
pop_kprobe() -> kprobe1 (current_kprobe)
pop_kprobe() -> kprobe1 (current_kprobe)
leaves "kprobe1" as "current_kprobe" on this cpu, instead of setting it
to NULL. In fact push_kprobe/pop_kprobe can only store a single state
(there is just one prev_kprobe in kprobe_ctlblk). Which is a hack but
sufficient, there is no need to have another prev_kprobe just to store
NULL. To make a simple and backportable fix simply reset "prev_kprobe"
when kprobe is poped from this "stack". No need to worry about
"kprobe_status" in this case, because its value is only checked when
current_kprobe != NULL.
Cc: stable@vger.kernel.org
Fixes: b9599798f9 ("[S390] kprobes: activation and deactivation")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Recent test_kprobe_missed kprobes kunit test uncovers the following error
(reported when CONFIG_DEBUG_ATOMIC_SLEEP is enabled):
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 662, name: kunit_try_catch
preempt_count: 0, expected: 0
RCU nest depth: 0, expected: 0
no locks held by kunit_try_catch/662.
irq event stamp: 280
hardirqs last enabled at (279): [<00000003e60a3d42>] __do_pgm_check+0x17a/0x1c0
hardirqs last disabled at (280): [<00000003e3bd774a>] kprobe_exceptions_notify+0x27a/0x318
softirqs last enabled at (0): [<00000003e3c5c890>] copy_process+0x14a8/0x4c80
softirqs last disabled at (0): [<0000000000000000>] 0x0
CPU: 46 PID: 662 Comm: kunit_try_catch Tainted: G N 6.2.0-173644-g44c18d77f0c0 #2
Hardware name: IBM 3931 A01 704 (LPAR)
Call Trace:
[<00000003e60a3a00>] dump_stack_lvl+0x120/0x198
[<00000003e3d02e82>] __might_resched+0x60a/0x668
[<00000003e60b9908>] __mutex_lock+0xc0/0x14e0
[<00000003e60bad5a>] mutex_lock_nested+0x32/0x40
[<00000003e3f7b460>] unregister_kprobe+0x30/0xd8
[<00000003e51b2602>] test_kprobe_missed+0xf2/0x268
[<00000003e51b5406>] kunit_try_run_case+0x10e/0x290
[<00000003e51b7dfa>] kunit_generic_run_threadfn_adapter+0x62/0xb8
[<00000003e3ce30f8>] kthread+0x2d0/0x398
[<00000003e3b96afa>] __ret_from_fork+0x8a/0xe8
[<00000003e60ccada>] ret_from_fork+0xa/0x40
The reason for this error report is that kprobes handling code failed
to restore irqs.
The problem is that when kprobe is triggered from another kprobe
post_handler current sequence of enable_singlestep / disable_singlestep
is the following:
enable_singlestep <- original kprobe (saves kprobe_saved_imask)
enable_singlestep <- kprobe triggered from post_handler (clobbers kprobe_saved_imask)
disable_singlestep <- kprobe triggered from post_handler (restores kprobe_saved_imask)
disable_singlestep <- original kprobe (restores wrong clobbered kprobe_saved_imask)
There is just one kprobe_ctlblk per cpu and both calls saves and
loads irq mask to kprobe_saved_imask. To fix the problem simply move
resume_execution (which calls disable_singlestep) before calling
post_handler. This also fixes the problem that post_handler is called
with pt_regs which were not yet adjusted after single-stepping.
Cc: stable@vger.kernel.org
Fixes: 4ba069b802 ("[S390] add kprobes support.")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Commit f05f62d042 ("s390/vmem: get rid of memory segment list")
reshuffled the call to vmem_add_mapping() in __segment_load(), which now
overwrites rc after it was set to contain the segment type code.
As result, __segment_load() will now always return 0 on success, which
corresponds to the segment type code SEG_TYPE_SW, i.e. a writeable
segment. This results in a kernel crash when loading a read-only segment
as dcssblk block device, and trying to write to it.
Instead of reshuffling code again, make sure to return the segment type
on success, and also describe this rather delicate and unexpected logic
in the function comment. Also initialize new segtype variable with
invalid value, to prevent possible future confusion.
Fixes: f05f62d042 ("s390/vmem: get rid of memory segment list")
Cc: <stable@vger.kernel.org> # 5.9+
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Pull LoongArch updates from Huacai Chen:
- Make -mstrict-align configurable
- Add kernel relocation and KASLR support
- Add single kernel image implementation for kdump
- Add hardware breakpoints/watchpoints support
- Add kprobes/kretprobes/kprobes_on_ftrace support
- Add LoongArch support for some selftests.
* tag 'loongarch-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: (23 commits)
selftests/ftrace: Add LoongArch kprobe args string tests support
selftests/seccomp: Add LoongArch selftesting support
tools: Add LoongArch build infrastructure
samples/kprobes: Add LoongArch support
LoongArch: Mark some assembler symbols as non-kprobe-able
LoongArch: Add kprobes on ftrace support
LoongArch: Add kretprobes support
LoongArch: Add kprobes support
LoongArch: Simulate branch and PC* instructions
LoongArch: ptrace: Add hardware single step support
LoongArch: ptrace: Add function argument access API
LoongArch: ptrace: Expose hardware breakpoints to debuggers
LoongArch: Add hardware breakpoints/watchpoints support
LoongArch: kdump: Add crashkernel=YM handling
LoongArch: kdump: Add single kernel image implementation
LoongArch: Add support for kernel address space layout randomization (KASLR)
LoongArch: Add support for kernel relocation
LoongArch: Add la_abs macro implementation
LoongArch: Add JUMP_VIRT_ADDR macro implementation to avoid using la.abs
LoongArch: Use la.pcrel instead of la.abs when it's trivially possible
...
Pull UML updates from Richard Weinberger:
- Add support for rust (yay!)
- Add support for LTO
- Add platform bus support to virtio-pci
- Various virtio fixes
- Coding style, spelling cleanups
* tag 'uml-for-linus-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (27 commits)
Documentation: rust: Fix arch support table
uml: vector: Remove unused definitions VECTOR_{WRITE,HEADERS}
um: virt-pci: properly remove PCI device from bus
um: virtio_uml: move device breaking into workqueue
um: virtio_uml: mark device as unregistered when breaking it
um: virtio_uml: free command if adding to virtqueue failed
UML: define RUNTIME_DISCARD_EXIT
virt-pci: add platform bus support
um-virt-pci: Make max delay configurable
um: virt-pci: implement pcibios_get_phb_of_node()
um: Support LTO
um: put power options in a menu
um: Use CFLAGS_vmlinux
um: Prevent building modules incompatible with MODVERSIONS
um: Avoid pcap multiple definition errors
um: Make the definition of cpu_data more compatible
x86: um: vdso: Add '%rcx' and '%r11' to the syscall clobber list
rust: arch/um: Add support for CONFIG_RUST under x86_64 UML
rust: arch/um: Disable FP/SIMD instruction to match x86
rust: arch/um: Use 'pie' relocation mode under UML
...
The Zbb optimized strncmp has two parts; a fast path that does XLEN/8B
per iteration, and a slow that does one byte per iteration.
The idea is to compare aligned XLEN chunks for most of strings, and do
the remainder tail in the slow path.
The Zbb strncmp has two issues in the fast path:
Incorrect remainder handling (wrong compare): Assume that the string
length is 9. On 64b systems, the fast path should do one iteration,
and one iteration in the slow path. Instead, both were done in the
fast path, which lead to incorrect results. An example:
strncmp("/dev/vda", "/dev/", 5);
Correct by changing "bgt" to "bge".
Missing NULL checks in the second string: This could lead to incorrect
results for:
strncmp("/dev/vda", "/dev/vda\0", 8);
Correct by adding an additional check.
Fixes: b6fcdb191e ("RISC-V: add zbb support to string functions")
Suggested-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230228184211.1585641-1-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Clang is unable to handle the situation that a chunk of inline
assembly ends with a compat branch instruction and then compiler
generates another control transfer instruction immediately after
this compat branch. The later instruction will end up in forbidden
slot and cause exception.
Workaround by add a option to control the use of compact branch.
Currently it's selected by CC_IS_CLANG and hopefully we can change
it to a version check in future if clang manages to fix it.
Fix boot on boston board.
Link: https://github.com/llvm/llvm-project/issues/61045
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Acked-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
To allow to access system controller registers from watchdog driver code
add a phandle in the watchdog 'wdt' node. This avoid using arch dependent
operations in driver code.
Reviewed-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Watchdog nodes must use 'watchdog' for node name. When a 'make dtbs_check'
is performed the following warning appears:
wdt@100: $nodename:0: 'wdt@100' does not match '^watchdog(@.*|-[0-9a-f])?$'
Fix this warning up properly renaming the node into 'watchdog'.
Reviewed-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
