commit a494398bde273143c2352dd373cad8211f7d94b2 upstream.
Nathan Chancellor reports that the s390 vmlinux fails to link with
GNU ld < 2.36 since commit 99cb0d917ffa ("arch: fix broken BuildID
for arm64 and riscv").
It happens for defconfig, or more specifically for CONFIG_EXPOLINE=y.
$ s390x-linux-gnu-ld --version | head -n1
GNU ld (GNU Binutils for Debian) 2.35.2
$ make -s ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- allnoconfig
$ ./scripts/config -e CONFIG_EXPOLINE
$ make -s ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- olddefconfig
$ make -s ARCH=s390 CROSS_COMPILE=s390x-linux-gnu-
`.exit.text' referenced in section `.s390_return_reg' of drivers/base/dd.o: defined in discarded section `.exit.text' of drivers/base/dd.o
make[1]: *** [scripts/Makefile.vmlinux:34: vmlinux] Error 1
make: *** [Makefile:1252: vmlinux] Error 2
arch/s390/kernel/vmlinux.lds.S wants to keep EXIT_TEXT:
.exit.text : {
EXIT_TEXT
}
But, at the same time, EXIT_TEXT is thrown away by DISCARD because
s390 does not define RUNTIME_DISCARD_EXIT.
I still do not understand why the latter wins after 99cb0d917ffa,
but defining RUNTIME_DISCARD_EXIT seems correct because the comment
line in arch/s390/kernel/vmlinux.lds.S says:
/*
* .exit.text is discarded at runtime, not link time,
* to deal with references from __bug_table
*/
Nathan also found that binutils commit 21401fc7bf67 ("Duplicate output
sections in scripts") cured this issue, so we cannot reproduce it with
binutils 2.36+, but it is better to not rely on it.
Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv")
Link: https://lore.kernel.org/all/Y7Jal56f6UBh1abE@dev-arch.thelio-3990X/
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20230105031306.1455409-1-masahiroy@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cd57953936f2213dfaccce10d20f396956222c7d upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 42e19e6f04984088b6f9f0507c4c89a8152d9730 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e9c9cb90e76ffaabcc7ca8f275d9e82195fd6367 upstream.
When debugging vmlinux with QEMU + GDB, the following GDB error may
occur:
(gdb) c
Continuing.
Warning:
Cannot insert breakpoint -1.
Cannot access memory at address 0xffffffffffff95c0
Command aborted.
(gdb)
The reason is that, when .interp section is present, GDB tries to
locate the file specified in it in memory and put a number of
breakpoints there (see enable_break() function in gdb/solib-svr4.c).
Sometimes GDB finds a bogus location that matches its heuristics,
fails to set a breakpoint and stops. This makes further debugging
impossible.
The .interp section contains misleading information anyway (vmlinux
does not need ld.so), so fix by discarding it.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No upstream commit exists: the problem addressed here is that 'commit
75309018a24d ("s390: add support for TIF_NOTIFY_SIGNAL")' was backported
to 5.10. This commit is broken, but nobody noticed upstream, since
shortly after s390 converted to generic entry with 'commit 56e62a737028
("s390: convert to generic entry")', which implicitly fixed the problem
outlined below.
Thread flag is set to TIF_NOTIFY_SIGNAL for io_uring work. The io work
user or syscall calls do_signal when either one of the TIF_SIGPENDING or
TIF_NOTIFY_SIGNAL flag is set. However, do_signal does consider only
TIF_SIGPENDING signal and ignores TIF_NOTIFY_SIGNAL condition. This
means get_signal is never invoked for TIF_NOTIFY_SIGNAL and hence the
flag is not cleared, which results in an endless do_signal loop.
Reference: 'commit 788d082426 ("io_uring: import 5.15-stable io_uring")'
Fixes: 75309018a24d ("s390: add support for TIF_NOTIFY_SIGNAL")
Cc: stable@vger.kernel.org # 5.10.162
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0e25498f8cd43c1b5aa327f373dd094e9a006da7 upstream.
There are two big uses of do_exit. The first is it's design use to be
the guts of the exit(2) system call. The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.
Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure. In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.
Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.
As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 82d3edb50a11bf3c5ef63294d5358ba230181413 upstream.
The current cmpxchg_double() loops within the perf hw sampling code do not
have READ_ONCE() semantics to read the old value from memory. This allows
the compiler to generate code which reads the "old" value several times
from memory, which again allows for inconsistencies.
For example:
/* Reset trailer (using compare-double-and-swap) */
do {
te_flags = te->flags & ~SDB_TE_BUFFER_FULL_MASK;
te_flags |= SDB_TE_ALERT_REQ_MASK;
} while (!cmpxchg_double(&te->flags, &te->overflow,
te->flags, te->overflow,
te_flags, 0ULL));
The compiler could generate code where te->flags used within the
cmpxchg_double() call may be refetched from memory and which is not
necessarily identical to the previous read version which was used to
generate te_flags. Which in turn means that an incorrect update could
happen.
Fix this by adding READ_ONCE() semantics to all cmpxchg_double()
loops. Given that READ_ONCE() cannot generate code on s390 which atomically
reads 16 bytes, use a private compare-and-swap-double implementation to
achieve that.
Also replace cmpxchg_double() with the private implementation to be able to
re-use the old value within the loops.
As a side effect this converts the whole code to only use bit fields
to read and modify bits within the hws trailer header.
Reported-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Reviewed-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/linux-s390/Y71QJBhNTIatvxUT@osiris/T/#ma14e2a5f7aa8ed4b94b6f9576799b3ad9c60f333
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c2337a40e04dde1692b5b0a46ecc59f89aaba8a1 upstream.
This commit addresses the following erroneous situation with file-based
kdump executed on a system with a valid IPL report.
On s390, a kdump kernel, its initrd and IPL report if present are loaded
into a special and reserved on boot memory region - crashkernel. When
a system crashes and kdump was activated before, the purgatory code
is entered first which swaps the crashkernel and [0 - crashkernel size]
memory regions. Only after that the kdump kernel is entered. For this
reason, the pointer to an IPL report in lowcore must point to the IPL report
after the swap and not to the address of the IPL report that was located in
crashkernel memory region before the swap. Failing to do so, makes the
kdump's decompressor try to read memory from the crashkernel memory region
which already contains the production's kernel memory.
The situation described above caused spontaneous kdump failures/hangs
on systems where the Secure IPL is activated because on such systems
an IPL report is always present. In that case kdump's decompressor tried
to parse an IPL report which frequently lead to illegal memory accesses
because an IPL report contains addresses to various data.
Cc: <stable@vger.kernel.org>
Fixes: 99feaa717e ("s390/kexec_file: Create ipl report and pass to next kernel")
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4727dc20e0422211a0e0c72b1ace4ed6096df8a6 ]
PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the
sense that we don't assign ->set_child_tid with our own structure. Just
ensure that every arch sets up the PF_IO_WORKER threads like kthreads
in the arch implementation of copy_thread().
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f44e07a8afdd713ddc1a8832c39372fe5dd86895 ]
The size of the TOD programmable field was incorrectly increased from
four to eight bytes with commit 1a2c5840ac ("s390/dump: cleanup CPU
save area handling").
This leads to an elf notes section NT_S390_TODPREG which has a size of
eight instead of four bytes in case of kdump, however even worse is
that the contents is incorrect: it is supposed to contain only the
contents of the TOD programmable field, but in fact contains a mix of
the TOD programmable field (32 bit upper bits) and parts of the CPU
timer register (lower 32 bits).
Fix this by simply changing the size of the todpreg field within the
save area structure. This will implicitly also fix the size of the
corresponding elf notes sections.
This also gets rid of this compile time warning:
in function ‘fortify_memcpy_chk’,
inlined from ‘save_area_add_regs’ at arch/s390/kernel/crash_dump.c:99:2:
./include/linux/fortify-string.h:413:25: error: call to ‘__read_overflow2_field’
declared with attribute warning: detected read beyond size of field
(2nd parameter); maybe use struct_group()? [-Werror=attribute-warning]
413 | __read_overflow2_field(q_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fixes: 1a2c5840ac ("s390/dump: cleanup CPU save area handling")
Reviewed-by: Christian Borntraeger <borntraeger@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>
commit c9305b6c1f52060377c72aebe3a701389e9f3172 upstream.
Add proper alignment for .nospec_call_table and .nospec_return_table in
vmlinux.
[hca@linux.ibm.com]: The problem with the missing alignment of the nospec
tables exist since a long time, however only since commit e6ed91fd0768
("s390/alternatives: remove padding generation code") and with
CONFIG_RELOCATABLE=n the kernel may also crash at boot time.
The above named commit reduced the size of struct alt_instr by one byte,
so its new size is 11 bytes. Therefore depending on the number of cpu
alternatives the size of the __alt_instructions array maybe odd, which
again also causes that the addresses of the nospec tables will be odd.
If the address of __nospec_call_start is odd and the kernel is compiled
With CONFIG_RELOCATABLE=n the compiler may generate code that loads the
address of __nospec_call_start with a 'larl' instruction.
This will generate incorrect code since the 'larl' instruction only works
with even addresses. In result the members of the nospec tables will be
accessed with an off-by-one offset, which subsequently may lead to
addressing exceptions within __nospec_revert().
Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/8719bf1ce4a72ebdeb575200290094e9ce047bcc.1661557333.git.jpoimboe@kernel.org
Cc: <stable@vger.kernel.org> # 4.16
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 13cccafe0edcd03bf1c841de8ab8a1c8e34f77d9 upstream.
The pointers for guarded storage and runtime instrumentation control
blocks are stored in the thread_struct of the associated task. These
pointers are initially copied on fork() via arch_dup_task_struct()
and then cleared via copy_thread() before fork() returns. If fork()
happens to fail after the initial task dup and before copy_thread(),
the newly allocated task and associated thread_struct memory are
freed via free_task() -> arch_release_task_struct(). This results in
a double free of the guarded storage and runtime info structs
because the fields in the failed task still refer to memory
associated with the source task.
This problem can manifest as a BUG_ON() in set_freepointer() (with
CONFIG_SLAB_FREELIST_HARDENED enabled) or KASAN splat (if enabled)
when running trinity syscall fuzz tests on s390x. To avoid this
problem, clear the associated pointer fields in
arch_dup_task_struct() immediately after the new task is copied.
Note that the RI flag is still cleared in copy_thread() because it
resides in thread stack memory and that is where stack info is
copied.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Fixes: 8d9047f8b9 ("s390/runtime instrumentation: simplify task exit handling")
Fixes: 7b83c6297d ("s390/guarded storage: simplify task exit handling")
Cc: <stable@vger.kernel.org> # 4.15
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20220816155407.537372-1-bfoster@redhat.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0828c4a39be57768b8788e8cbd0d84683ea757e5 ]
commit e23a8020ce ("s390/kexec_file: Signature verification prototype")
adds support for KEXEC_SIG verification with keys from platform keyring
but the built-in keys and secondary keyring are not used.
Add support for the built-in keys and secondary keyring as x86 does.
Fixes: e23a8020ce ("s390/kexec_file: Signature verification prototype")
Cc: stable@vger.kernel.org
Cc: Philipp Rudo <prudo@linux.ibm.com>
Cc: kexec@lists.infradead.org
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: "Lee, Chun-Yi" <jlee@suse.com>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dc306186a130c6d9feb0aabc1c71b8ed1674a3bf ]
Virtual addresses of vmcore_info and os_info members are
wrongly passed to copy_oldmem_kernel(), while the function
expects physical address of the source. Instead, __pa()
macro should have been applied.
Yet, use of __pa() macro could be somehow confusing, since
copy_oldmem_kernel() may treat the source as an offset, not
as a direct physical address (that depens from the oldmem
availability and location).
Fix the virtual vs physical address confusion and make the
way the old lowcore is read consistent across all sources.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e4f74400308cb8abde5fdc9cad609c2aba32110c upstream.
s390x appears to present two RNG interfaces:
- a "TRNG" that gathers entropy using some hardware function; and
- a "DRBG" that takes in a seed and expands it.
Previously, the TRNG was wired up to arch_get_random_{long,int}(), but
it was observed that this was being called really frequently, resulting
in high overhead. So it was changed to be wired up to arch_get_random_
seed_{long,int}(), which was a reasonable decision. Later on, the DRBG
was then wired up to arch_get_random_{long,int}(), with a complicated
buffer filling thread, to control overhead and rate.
Fortunately, none of the performance issues matter much now. The RNG
always attempts to use arch_get_random_seed_{long,int}() first, which
means a complicated implementation of arch_get_random_{long,int}() isn't
really valuable or useful to have around. And it's only used when
reseeding, which means it won't hit the high throughput complications
that were faced before.
So this commit returns to an earlier design of just calling the TRNG in
arch_get_random_seed_{long,int}(), and returning false in arch_get_
random_{long,int}().
Part of what makes the simplification possible is that the RNG now seeds
itself using the TRNG at bootup. But this only works if the TRNG is
detected early in boot, before random_init() is called. So this commit
also causes that check to happen in setup_arch().
Cc: stable@vger.kernel.org
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Ingo Franzki <ifranzki@linux.ibm.com>
Cc: Juergen Christ <jchrist@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20220610222023.378448-1-Jason@zx2c4.com
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit be857b7f77d130dbbd47c91fc35198b040f35865 ]
Events CPU_CYCLES and INSTRUCTIONS can be submitted with two different
perf_event attribute::type values:
- PERF_TYPE_HARDWARE: when invoked via perf tool predefined events name
cycles or cpu-cycles or instructions.
- pmu->type: when invoked via perf tool event name cpu_cf/CPU_CYLCES/ or
cpu_cf/INSTRUCTIONS/. This invocation also selects the PMU to which
the event belongs.
Handle both type of invocations identical for events CPU_CYLCES and
INSTRUCTIONS. They address the same hardware.
The result is different when event modifier exclude_kernel is also set.
Invocation with event modifier for user space event counting fails.
Output before:
# perf stat -e cpum_cf/cpu_cycles/u -- true
Performance counter stats for 'true':
<not supported> cpum_cf/cpu_cycles/u
0.000761033 seconds time elapsed
0.000076000 seconds user
0.000725000 seconds sys
#
Output after:
# perf stat -e cpum_cf/cpu_cycles/u -- true
Performance counter stats for 'true':
349,613 cpum_cf/cpu_cycles/u
0.000844143 seconds time elapsed
0.000079000 seconds user
0.000800000 seconds sys
#
Fixes: 6a82e23f45 ("s390/cpumf: Adjust registration of s390 PMU device drivers")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
[agordeev@linux.ibm.com corrected commit ID of Fixes commit]
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c9bfb460c3e4da2462e16b0f0b200990b36b1dd2 upstream.
Since commit 1179f170b6 ("s390: fix fpu restore in entry.S"), the
sie_block pointer is located at empty1[1], but in sie_block() it was
taken from empty1[0].
This leads to a random pointer being dereferenced, possibly causing
system crash.
This problem can be observed when running a simple guest with an endless
loop and recording the cpu-clock event:
sudo perf kvm --guestvmlinux=<guestkernel> --guest top -e cpu-clock
With this fix, the correct guest address is shown.
Fixes: 1179f170b6 ("s390: fix fpu restore in entry.S")
Cc: stable@vger.kernel.org
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f3b7e73b2c6619884351a3a0a7468642f852b8a2 upstream.
If the size of the PLT entries generated by apply_rela() exceeds
64KiB, the first ones can no longer reach __jump_r1 with brc. Fix by
using brcl. An alternative solution is to add a __jump_r1 copy after
every 64KiB, however, the space savings are quite small and do not
justify the additional complexity.
Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Cc: stable@vger.kernel.org
Reported-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 41967a37b8eedfee15b81406a9f3015be90d3980 ]
arch_kexec_apply_relocations_add currently ignores all errors returned
by arch_kexec_do_relocs. This means that every unknown relocation is
silently skipped causing unpredictable behavior while the relocated code
runs. Fix this by checking for errors and fail kexec_file_load if an
unknown relocation type is encountered.
The problem was found after gcc changed its behavior and used
R_390_PLT32DBL relocations for brasl instruction and relied on ld to
resolve the relocations in the final link in case direct calls are
possible. As the purgatory code is only linked partially (option -r)
ld didn't resolve the relocations leaving them for arch_kexec_do_relocs.
But arch_kexec_do_relocs doesn't know how to handle R_390_PLT32DBL
relocations so they were silently skipped. This ultimately caused an
endless loop in the purgatory as the brasl instructions kept branching
to itself.
Fixes: 71406883fd ("s390/kexec_file: Add kexec_file_load system call")
Reported-by: Tao Liu <ltao@redhat.com>
Signed-off-by: Philipp Rudo <prudo@redhat.com>
Link: https://lore.kernel.org/r/20211208130741.5821-3-prudo@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5dbc4cb4667457b0c53bcd7bff11500b3c362975 ]
There is a difference in how architectures treat "mem=" option. For some
that is an amount of online memory, for s390 and x86 this is the limiting
max address. Some memblock api like memblock_enforce_memory_limit()
take limit argument and explicitly treat it as the size of online memory,
and use __find_max_addr to convert it to an actual max address. Current
s390 usage:
memblock_enforce_memory_limit(memblock_end_of_DRAM());
yields different results depending on presence of memory holes (offline
memory blocks in between online memory). If there are no memory holes
limit == max_addr in memblock_enforce_memory_limit() and it does trim
online memory and reserved memory regions. With memory holes present it
actually does nothing.
Since we already use memblock_remove() explicitly to trim online memory
regions to potential limit (think mem=, kdump, addressing limits, etc.)
drop the usage of memblock_enforce_memory_limit() altogether. Trimming
reserved regions should not be required, since we now use
memblock_set_current_limit() to limit allocations and any explicit memory
reservations above the limit is an actual problem we should not hide.
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 20c76e242e7025bd355619ba67beb243ba1a1e95 ]
kexec_file_add_ipl_report ignores that ipl_report_finish may fail and
can return an error pointer instead of a valid pointer.
Fix this and simplify by returning NULL in case of an error and let
the only caller handle this case.
Fixes: 99feaa717e ("s390/kexec_file: Create ipl report and pass to next kernel")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3322ba0d7bea1e24ae464418626f6a15b69533ab ]
Kernel support for the newer PCI mio instructions can be toggled off
with the pci=nomio command line option which needs to integrate with
common code PCI option parsing. However this option then toggles static
branches which can't be toggled yet in an early_param() call.
Thus commit 9964f396f1 ("s390: fix setting of mio addressing control")
moved toggling the static branches to the PCI init routine.
With this setup however we can't check for mio support outside the PCI
code during early boot, i.e. before switching the static branches, which
we need to be able to export this as an ELF HWCAP.
Improve on this by turning mio availability into a machine flag that
gets initially set based on CONFIG_PCI and the facility bit and gets
toggled off if pci=nomio is found during PCI option parsing allowing
simple access to this machine flag after early init.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5492886c14744d239e87f1b0b774b5a341e755cc ]
In case of a jump label print the real address of the piece of code
where a mismatch was detected. This is right before the system panics,
so there is nothing revealed.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9372a82892c2caa6bccab9a4081166fa769699f8 ]
Currently allocation and registration of s390dbf debug areas are tied
together. As a result, a debug area cannot be unregistered and
re-registered while any process has an associated debugfs file open.
Fix this by splitting alloc/release from register/unregister.
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1204777867e8486a88dbb4793fe256b31ea05eeb ]
Any previously recorded s390dbf debug data is reset when a debug area
is resized using the 'pages' sysfs attribute. This can make
live-debugging unnecessarily complex.
Fix this by copying existing debug data to the newly allocated debug
area when resizing.
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b8e9cc20b808e26329090c19ff80b7f5098e98ff ]
tinyconfig fails to boot, because without CONFIG_BUG report_bug()
always returns BUG_TRAP_TYPE_BUG, which causes mc 0,0 in
test_monitor_call() to panic. Fix by skipping the test without
CONFIG_BUG.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b7d91d230a119fdcc334d10c9889ce9c5e15118b ]
Console name reported in /proc/consoles:
ttyS1 -W- (EC p ) 4:65
does not match the char device name:
crw--w---- 1 root root 4, 65 May 17 12:18 /dev/ttysclp0
so debian-installer inside a QEMU s390x instance gets confused and fails
to start with the following error:
steal-ctty: No such file or directory
Signed-off-by: Valentin Vidic <vvidic@valentin-vidic.from.hr>
Link: https://lore.kernel.org/r/20210427194010.9330-1-vvidic@valentin-vidic.from.hr
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6a942f5780545ebd11aca8b3ac4b163397962322 upstream.
S390's init_idle_preempt_count(p, cpu) doesn't actually let us initialize the
preempt_count of the requested CPU's idle task: it unconditionally writes
to the current CPU's. This clearly conflicts with idle_threads_init(),
which intends to initialize *all* the idle tasks, including their
preempt_count (or their CPU's, if the arch uses a per-CPU preempt_count).
Unfortunately, it seems the way s390 does things doesn't let us initialize
every possible CPU's preempt_count early on, as the pages where this
resides are only allocated when a CPU is brought up and are freed when it
is brought down.
Let the arch-specific code set a CPU's preempt_count when its lowcore is
allocated, and turn init_idle_preempt_count() into an empty stub.
Fixes: f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20210707163338.1623014-1-valentin.schneider@arm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ]
As pointed out by commit
de9b8f5dcb ("sched: Fix crash trying to dequeue/enqueue the idle thread")
init_idle() can and will be invoked more than once on the same idle
task. At boot time, it is invoked for the boot CPU thread by
sched_init(). Then smp_init() creates the threads for all the secondary
CPUs and invokes init_idle() on them.
As the hotplug machinery brings the secondaries to life, it will issue
calls to idle_thread_get(), which itself invokes init_idle() yet again.
In this case it's invoked twice more per secondary: at _cpu_up(), and at
bringup_cpu().
Given smp_init() already initializes the idle tasks for all *possible*
CPUs, no further initialization should be required. Now, removing
init_idle() from idle_thread_get() exposes some interesting expectations
with regards to the idle task's preempt_count: the secondary startup always
issues a preempt_disable(), requiring some reset of the preempt count to 0
between hot-unplug and hotplug, which is currently served by
idle_thread_get() -> idle_init().
Given the idle task is supposed to have preemption disabled once and never
see it re-enabled, it seems that what we actually want is to initialize its
preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove
init_idle() from idle_thread_get().
Secondary startups were patched via coccinelle:
@begone@
@@
-preempt_disable();
...
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 85b18d7b5e7ffefb2f076186511d39c4990aa005 upstream.
Turns out that the bit 61 in the TEID is not always 1 and if that's
the case the address space ID and the address are
unpredictable. Without an address and its address space ID we can't
export memory and hence we can only send a SIGSEGV to the process or
panic the kernel depending on who caused the exception.
Unfortunately bit 61 is only reliable if we have the "misc" UV feature
bit.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Fixes: 084ea4d611 ("s390/mm: add (non)secure page access exceptions handlers")
Cc: stable@vger.kernel.org
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5bcbe3285fb614c49db6b238253f7daff7e66312 upstream.
The size of SIE critical section is calculated wrongly
as result of a missed subtraction in commit 0b0ed657fe
("s390: remove critical section cleanup from entry.S")
Fixes: 0b0ed657fe ("s390: remove critical section cleanup from entry.S")
Cc: <stable@vger.kernel.org>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b208108638c4bd3215792415944467c36f5dfd97 upstream.
The PoP documents:
134: The vector packed decimal facility is installed in the
z/Architecture architectural mode. When bit 134 is
one, bit 129 is also one.
135: The vector enhancements facility 1 is installed in
the z/Architecture architectural mode. When bit 135
is one, bit 129 is also one.
Looks like we confuse the vector enhancements facility 1 ("EXT") with the
Vector packed decimal facility ("BCD"). Let's fix the facility checks.
Detected while working on QEMU/tcg z14 support and only unlocking
the vector enhancements facility 1, but not the vector packed decimal
facility.
Fixes: 2583b848ca ("s390: report new vector facilities")
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20210503121244.25232-1-david@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a994eddb947ea9ebb7b14d9a1267001699f0a136 ]
Currently psw_idle does not allocate a stack frame and does not
save its r14 and r15 into the save area. Even though this is valid from
call ABI point of view, because psw_idle does not make any calls
explicitly, in reality psw_idle is an entry point for controlled
transition into serving interrupts. So, in practice, psw_idle stack
frame is analyzed during stack unwinding. Depending on build options
that r14 slot in the save area of psw_idle might either contain a value
saved by previous sibling call or complete garbage.
[task 0000038000003c28] do_ext_irq+0xd6/0x160
[task 0000038000003c78] ext_int_handler+0xba/0xe8
[task *0000038000003dd8] psw_idle_exit+0x0/0x8 <-- pt_regs
([task 0000038000003dd8] 0x0)
[task 0000038000003e10] default_idle_call+0x42/0x148
[task 0000038000003e30] do_idle+0xce/0x160
[task 0000038000003e70] cpu_startup_entry+0x36/0x40
[task 0000038000003ea0] arch_call_rest_init+0x76/0x80
So, to make a stacktrace nicer and actually point for the real caller of
psw_idle in this frequently occurring case, make psw_idle save its r14.
[task 0000038000003c28] do_ext_irq+0xd6/0x160
[task 0000038000003c78] ext_int_handler+0xba/0xe8
[task *0000038000003dd8] psw_idle_exit+0x0/0x6 <-- pt_regs
([task 0000038000003dd8] arch_cpu_idle+0x3c/0xd0)
[task 0000038000003e10] default_idle_call+0x42/0x148
[task 0000038000003e30] do_idle+0xce/0x160
[task 0000038000003e70] cpu_startup_entry+0x36/0x40
[task 0000038000003ea0] arch_call_rest_init+0x76/0x80
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 72bbc226ed2ef0a46c165a482861fff00dd6d4e1 upstream.
When converting the vdso assembler code to C it was forgotten to
actually copy the tod_steering_delta value to vdso_data page.
Which in turn means that tod clock steering will not work correctly.
Fix this by simply copying the value whenever it is updated.
Fixes: 4bff8cb545 ("s390: convert to GENERIC_VDSO")
Cc: <stable@vger.kernel.org> # 5.10
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d54cb7d54877d529bc1e0e1f47a3dd082f73add3 upstream.
Commit 152e9b8676 ("s390/vtime: steal time exponential moving average")
inadvertently changed the input value for account_steal_time() from
"cputime_to_nsecs(steal)" to just "steal", resulting in broken increased
steal time accounting.
Fix this by changing it back to "cputime_to_nsecs(steal)".
Fixes: 152e9b8676 ("s390/vtime: steal time exponential moving average")
Cc: <stable@vger.kernel.org> # 5.1
Reported-by: Sabine Forkel <sabine.forkel@de.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 62c8dca9e194326802b43c60763f856d782b225c ]
Avoid a potentially large stack frame and overflow by making
"cpumask_t avail" a static variable. There is no concurrent
access due to the existing locking.
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>
commit b29c5093820d333eef22f58cd04ec0d089059c39 upstream.
The stck/stckf instruction used within the inline assembly within
do_account_vtime() changes the condition code. This is not reflected
with the clobber list, and therefore might result in incorrect code
generation.
It seems unlikely that the compiler could generate incorrect code
considering the surrounding C code, but it must still be fixed.
Cc: <stable@vger.kernel.org>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e82080e1f456467cc185fe65ee69fe9f9bd0b576 upstream.
The number reported by the query is N-1 and I think people reading the
sysfs file would expect N instead. For users creating VMs there's no
actual difference because KVM's limit is currently below the UV's
limit.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Fixes: a0f60f8431 ("s390/protvirt: Add sysfs firmware interface for Ultravisor information")
Cc: stable@vger.kernel.org
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9365965db0c7ca7fc81eee27c21d8522d7102c32 ]
Clear the kernel stack backchain before potentially calling the
lockdep trace_hardirqs_off/on functions. Without this walking the
kernel backchain, e.g. during a panic, might stop too early.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 454efcf82ea17d7efeb86ebaa20775a21ec87d27 upstream.
When a machine check interrupt is triggered during idle, the code
is using the async timer/clock for idle time calculation. It should use
the machine check enter timer/clock which is passed to the macro.
Fixes: 0b0ed657fe ("s390: remove critical section cleanup from entry.S")
Cc: <stable@vger.kernel.org> # 5.8
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e259b3fafa7de362b04ecd86e7fa9a9e9273e5fb upstream.
During removal of the critical section cleanup the calculation
of mt_cycles during idle was removed. This causes invalid
accounting on systems with SMT enabled.
Fixes: 0b0ed657fe ("s390: remove critical section cleanup from entry.S")
Cc: <stable@vger.kernel.org> # 5.8
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b5e438ebd7e808d1d2435159ac4742e01a94b8da upstream.
Not resetting the SMT siblings might leave them in unpredictable
state. One of the observed problems was that the CPU timer wasn't
reset and therefore large system time values where accounted during
CPU bringup.
Cc: <stable@kernel.org> # 4.0
Fixes: 10ad34bc76 ("s390: add SMT support")
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With commit 58c644ba51 ("sched/idle: Fix arch_cpu_idle() vs
tracing") common code calls arch_cpu_idle() with a lockdep state that
tells irqs are on.
This doesn't work very well for s390: psw_idle() will enable interrupts
to wait for an interrupt. As soon as an interrupt occurs the interrupt
handler will verify if the old context was psw_idle(). If that is the
case the interrupt enablement bits in the old program status word will
be cleared.
A subsequent test in both the external as well as the io interrupt
handler checks if in the old context interrupts were enabled. Due to
the above patching of the old program status word it is assumed the
old context had interrupts disabled, and therefore a call to
TRACE_IRQS_OFF (aka trace_hardirqs_off_caller) is skipped. Which in
turn makes lockdep incorrectly "think" that interrupts are enabled
within the interrupt handler.
Fix this by unconditionally calling TRACE_IRQS_OFF when entering
interrupt handlers. Also call unconditionally TRACE_IRQS_ON when
leaving interrupts handlers.
This leaves the special psw_idle() case, which now returns with
interrupts disabled, but has an "irqs on" lockdep state. So callers of
psw_idle() must adjust the state on their own, if required. This is
currently only __udelay_disabled().
Fixes: 58c644ba51 ("sched/idle: Fix arch_cpu_idle() vs tracing")
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
idle path. Similar to the entry path the low level idle functions have to
be non-instrumentable.
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Merge tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
"Two more places which invoke tracing from RCU disabled regions in the
idle path.
Similar to the entry path the low level idle functions have to be
non-instrumentable"
* tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
intel_idle: Fix intel_idle() vs tracing
sched/idle: Fix arch_cpu_idle() vs tracing
