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git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull AFS updates from David Howells:
"Minor cleanups and fix:
- Minor fix to make some debugging statements display information
from the correct iov_iter.
- Rename some members and variables to make things more obvious or
consistent.
- Provide a helper to wrap increments of the usage count on the
afs_read struct.
- Use scnprintf() to print into a stack buffer rather than sprintf().
- Remove some set but unused variables"
* tag 'afs-next-20191121' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Remove set but not used variable 'ret'
afs: Remove set but not used variables 'before', 'after'
afs: xattr: use scnprintf
afs: Introduce an afs_get_read() refcount helper
afs: Rename desc -> req in afs_fetch_data()
afs: Switch the naming of call->iter and call->_iter
afs: Use call->_iter not &call->iter in debugging statements
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git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"This merge window saw the the following new featuers added to ext4:
- Direct I/O via iomap (required the iomap-for-next branch from
Darrick as a prereq).
- Support for using dioread-nolock where the block size < page size.
- Support for encryption for file systems where the block size < page
size.
- Rework of journal credits handling so a revoke-heavy workload will
not cause the journal to run out of space.
- Replace bit-spinlocks with spinlocks in jbd2
Also included were some bug fixes and cleanups, mostly to clean up
corner cases from fuzzed file systems and error path handling"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (59 commits)
ext4: work around deleting a file with i_nlink == 0 safely
ext4: add more paranoia checking in ext4_expand_extra_isize handling
jbd2: make jbd2_handle_buffer_credits() handle reserved handles
ext4: fix a bug in ext4_wait_for_tail_page_commit
ext4: bio_alloc with __GFP_DIRECT_RECLAIM never fails
ext4: code cleanup for get_next_id
ext4: fix leak of quota reservations
ext4: remove unused variable warning in parse_options()
ext4: Enable encryption for subpage-sized blocks
fs/buffer.c: support fscrypt in block_read_full_page()
ext4: Add error handling for io_end_vec struct allocation
jbd2: Fine tune estimate of necessary descriptor blocks
jbd2: Provide trace event for handle restarts
ext4: Reserve revoke credits for freed blocks
jbd2: Make credit checking more strict
jbd2: Rename h_buffer_credits to h_total_credits
jbd2: Reserve space for revoke descriptor blocks
jbd2: Drop jbd2_space_needed()
jbd2: Account descriptor blocks into t_outstanding_credits
jbd2: Factor out common parts of stopping and restarting a handle
...
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Pull splice fix from Darrick Wong:
"Fix another place in the splice code where a pipe could ask a
filesystem for a longer read than the pipe actually has free buffer
space"
* tag 'vfs-5.5-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
splice: only read in as much information as there is pipe buffer space
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Pull iomap updates from Darrick Wong:
"In this release, we hoisted as much of XFS' writeback code into iomap
as was practicable, refactored the unshare file data function, added
the ability to perform buffered io copy on write, and tweaked various
parts of the directio implementation as needed to port ext4's directio
code (that will be a separate pull).
Summary:
- Make iomap_dio_rw callers explicitly tell us if they want us to
wait
- Port the xfs writeback code to iomap to complete the buffered io
library functions
- Refactor the unshare code to share common pieces
- Add support for performing copy on write with buffered writes
- Other minor fixes
- Fix unchecked return in iomap_bmap
- Fix a type casting bug in a ternary statement in
iomap_dio_bio_actor
- Improve tracepoints for easier diagnostic ability
- Fix pipe page leakage in directio reads"
* tag 'iomap-5.5-merge-11' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (31 commits)
iomap: Fix pipe page leakage during splicing
iomap: trace iomap_appply results
iomap: fix return value of iomap_dio_bio_actor on 32bit systems
iomap: iomap_bmap should check iomap_apply return value
iomap: Fix overflow in iomap_page_mkwrite
fs/iomap: remove redundant check in iomap_dio_rw()
iomap: use a srcmap for a read-modify-write I/O
iomap: renumber IOMAP_HOLE to 0
iomap: use write_begin to read pages to unshare
iomap: move the zeroing case out of iomap_read_page_sync
iomap: ignore non-shared or non-data blocks in xfs_file_dirty
iomap: always use AOP_FLAG_NOFS in iomap_write_begin
iomap: remove the unused iomap argument to __iomap_write_end
iomap: better document the IOMAP_F_* flags
iomap: enhance writeback error message
iomap: pass a struct page to iomap_finish_page_writeback
iomap: cleanup iomap_ioend_compare
iomap: move struct iomap_page out of iomap.h
iomap: warn on inline maps in iomap_writepage_map
iomap: lift the xfs writeback code to iomap
...
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The DeviceTree binding document was converted to YAML in a patch that
is being merged through the devicetree tree, as such this patch needs to
be rewritten and is currently cause for a merge conflict.
This reverts commit 14ea1d04ed0f7bae60951bdb8eeaa55cdbb26c73.
Signed-off-by: Bjorn Andersson <[email protected]>
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When a classful qdisc's child qdisc has set the flag
TCQ_F_CPUSTATS (pfifo_fast for example), the child qdisc's
cpu_bstats should be passed to gnet_stats_copy_basic(),
but many classful qdisc didn't do that. As a result,
`tc -s class show dev DEV` always return 0 for bytes and
packets in this case.
Pass the child qdisc's cpu_bstats to gnet_stats_copy_basic()
to fix this issue.
The qstats also has this problem, but it has been fixed
in 5dd431b6b9 ("net: sched: introduce and use qstats read...")
and bstats still remains buggy.
Fixes: 22e0f8b9322c ("net: sched: make bstats per cpu and estimator RCU safe")
Signed-off-by: Dust Li <[email protected]>
Signed-off-by: Tony Lu <[email protected]>
Acked-by: Cong Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull hmm updates from Jason Gunthorpe:
"This is another round of bug fixing and cleanup. This time the focus
is on the driver pattern to use mmu notifiers to monitor a VA range.
This code is lifted out of many drivers and hmm_mirror directly into
the mmu_notifier core and written using the best ideas from all the
driver implementations.
This removes many bugs from the drivers and has a very pleasing
diffstat. More drivers can still be converted, but that is for another
cycle.
- A shared branch with RDMA reworking the RDMA ODP implementation
- New mmu_interval_notifier API. This is focused on the use case of
monitoring a VA and simplifies the process for drivers
- A common seq-count locking scheme built into the
mmu_interval_notifier API usable by drivers that call
get_user_pages() or hmm_range_fault() with the VA range
- Conversion of mlx5 ODP, hfi1, radeon, nouveau, AMD GPU, and Xen
GntDev drivers to the new API. This deletes a lot of wonky driver
code.
- Two improvements for hmm_range_fault(), from testing done by Ralph"
* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
mm/hmm: remove hmm_range_dma_map and hmm_range_dma_unmap
mm/hmm: make full use of walk_page_range()
xen/gntdev: use mmu_interval_notifier_insert
mm/hmm: remove hmm_mirror and related
drm/amdgpu: Use mmu_interval_notifier instead of hmm_mirror
drm/amdgpu: Use mmu_interval_insert instead of hmm_mirror
drm/amdgpu: Call find_vma under mmap_sem
nouveau: use mmu_interval_notifier instead of hmm_mirror
nouveau: use mmu_notifier directly for invalidate_range_start
drm/radeon: use mmu_interval_notifier_insert
RDMA/hfi1: Use mmu_interval_notifier_insert for user_exp_rcv
RDMA/odp: Use mmu_interval_notifier_insert()
mm/hmm: define the pre-processor related parts of hmm.h even if disabled
mm/hmm: allow hmm_range to be used with a mmu_interval_notifier or hmm_mirror
mm/mmu_notifier: add an interval tree notifier
mm/mmu_notifier: define the header pre-processor parts even if disabled
mm/hmm: allow snapshot of the special zero page
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The recently updated ALE APIs cpsw_ale_del_mcast() and
cpsw_ale_del_vlan_modify() have an issue and will not delete ALE entry even
if VLAN/mcast group has no more members. Hence fix it here and delete ALE
entry if !port_mask.
The issue affected only new cpsw switchdev driver.
Fixes: e85c14370783 ("net: ethernet: ti: ale: modify vlan/mdb api for switchdev")
Signed-off-by: Grygorii Strashko <[email protected]>
Acked-by: Ilias Apalodimas <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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If IPV6 is not set and CONFIG_MLX5_ESWITCH is y,
building fails:
drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c:322:5: error: redefinition of mlx5e_tc_tun_create_header_ipv6
int mlx5e_tc_tun_create_header_ipv6(struct mlx5e_priv *priv,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c:7:0:
drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.h:67:1: note: previous definition of mlx5e_tc_tun_create_header_ipv6 was here
mlx5e_tc_tun_create_header_ipv6(struct mlx5e_priv *priv,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Use #ifdef to guard this, also move mlx5e_route_lookup_ipv6
to cleanup unused warning.
Reported-by: Hulk Robot <[email protected]>
Fixes: e689e998e102 ("net/mlx5e: TC, Stub out ipv6 tun create header function")
Signed-off-by: YueHaibing <[email protected]>
Acked-by: Saeed Mahameed <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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git://anongit.freedesktop.org/drm/drm
Pull drm coherent memory support for vmwgfx from Dave Airlie:
"This is a separate pull for the mm pagewalking + drm/vmwgfx work
Thomas did and you were involved in, I've left it separate in case you
don't feel as comfortable with it as the other stuff.
It has mm acks/r-b in the right places from what I can see"
* tag 'drm-vmwgfx-coherent-2019-11-29' of git://anongit.freedesktop.org/drm/drm:
drm/vmwgfx: Add surface dirty-tracking callbacks
drm/vmwgfx: Implement an infrastructure for read-coherent resources
drm/vmwgfx: Use an RBtree instead of linked list for MOB resources
drm/vmwgfx: Implement an infrastructure for write-coherent resources
mm: Add write-protect and clean utilities for address space ranges
mm: Add a walk_page_mapping() function to the pagewalk code
mm: pagewalk: Take the pagetable lock in walk_pte_range()
mm: Remove BUG_ON mmap_sem not held from xxx_trans_huge_lock()
drm/ttm: Convert vm callbacks to helpers
drm/ttm: Remove explicit typecasts of vm_private_data
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... for better readability.
No functional changes.
[ Minor edit. ]
Signed-off-by: Borislav Petkov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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The livepatch consistency model requires reliable stack tracing
architecture support in order to work properly. In order to achieve
this, two main issues have to be solved. First, reliable and consistent
call chain backtracing has to be ensured. Second, the unwinder needs to
be able to detect stack corruptions and return errors.
The "zSeries ELF Application Binary Interface Supplement" says:
"The stack pointer points to the first word of the lowest allocated
stack frame. If the "back chain" is implemented this word will point to
the previously allocated stack frame (towards higher addresses), except
for the first stack frame, which shall have a back chain of zero (NULL).
The stack shall grow downwards, in other words towards lower addresses."
"back chain" is optional. GCC option -mbackchain enables it. Quoting
Martin Schwidefsky [1]:
"The compiler is called with the -mbackchain option, all normal C
function will store the backchain in the function prologue. All
functions written in assembler code should do the same, if you find one
that does not we should fix that. The end result is that a task that
*voluntarily* called schedule() should have a proper backchain at all
times.
Dependent on the use case this may or may not be enough. Asynchronous
interrupts may stop the CPU at the beginning of a function, if kernel
preemption is enabled we can end up with a broken backchain. The
production kernels for IBM Z are all compiled *without* kernel
preemption. So yes, we might get away without the objtool support.
On a side-note, we do have a line item to implement the ORC unwinder for
the kernel, that includes the objtool support. Once we have that we can
drop the -mbackchain option for the kernel build. That gives us a nice
little performance benefit. I hope that the change from backchain to the
ORC unwinder will not be too hard to implement in the livepatch tools."
Since -mbackchain is enabled by default when the kernel is compiled, the
call chain backtracing should be currently ensured and objtool should
not be necessary for livepatch purposes.
Regarding the second issue, stack corruptions and non-reliable states
have to be recognized by the unwinder. Mainly it means to detect
preemption or page faults, the end of the task stack must be reached,
return addresses must be valid text addresses and hacks like function
graph tracing and kretprobes must be properly detected.
Unwinding a running task's stack is not a problem, because there is a
livepatch requirement that every checked task is blocked, except for the
current task. Due to that, the implementation can be much simpler
compared to the existing non-reliable infrastructure. We can consider a
task's kernel/thread stack only and skip the other stacks.
[1] 20180912121106.31ffa97c@mschwideX1 [not archived on lore.kernel.org]
Link: https://lkml.kernel.org/r/[email protected]
Reviewed-by: Heiko Carstens <[email protected]>
Tested-by: Miroslav Benes <[email protected]>
Signed-off-by: Miroslav Benes <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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ABI requires SP to be aligned 8 bytes, report unwinding error otherwise.
Link: https://lkml.kernel.org/r/[email protected]
Reviewed-by: Heiko Carstens <[email protected]>
Tested-by: Miroslav Benes <[email protected]>
Signed-off-by: Miroslav Benes <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Currently unwinder unconditionally returns %r14 from the first frame
pointed by %r15 from pt_regs. A task could be interrupted when a function
already allocated this frame (if it needs it) for its callees or to
store local variables. In that case this frame would contain random
values from stack or values stored there by a callee. As we are only
interested in %r14 to get potential return address, skip bogus return
addresses which doesn't belong to kernel text.
This helps to avoid duplicating filtering logic in unwider users, most
of which use unwind_get_return_address() and would choke on bogus 0
address returned by it otherwise.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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A comment in arch/s390/include/asm/unwind.h says:
> If 'first_frame' is not zero unwind_start skips unwind frames until it
> reaches the specified stack pointer.
> The end of the unwinding is indicated with unwind_done, this can be true
> right after unwind_start, e.g. with first_frame!=0 that can not be found.
> unwind_next_frame skips to the next frame.
> Once the unwind is completed unwind_error() can be used to check if there
> has been a situation where the unwinder could not correctly understand
> the tasks call chain.
With this change backchain unwinder now comply with behaviour
described. As well as matches orc unwinder implementation. Now unwinder
starts from reliable state, i.e. __unwind_start own stack frame is
taken or stack frame generated by __switch_to (ksp) - both known to be
valid. In case of pt_regs %r15 is better match for pt_regs psw, than
sometimes random "sp" caller passed.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Add unwinding from program check handler tests. Unwinder should be able
to unwind through pt_regs stored by program check handler on task stack.
Signed-off-by: Vasily Gorbik <[email protected]>
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Add unwinding from irq context tests. Unwinder should be able to unwind
through irq stack to task stack up to task pt_regs.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Add stack name, sp and reliable information into test unwinding
results. Also consider ip outside of kernel text as failure if the
state is reported reliable.
Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Add CALL_ON_STACK helper testing. Tests make sure that we can unwind from
switched stack to original one up to task pt_regs (nodat -> task stack).
UWM_SWITCH_STACK could not be used together with UWM_THREAD because
get_stack_info explicitly restricts unwinding to task stack if
task != current.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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CALL_ON_STACK defines and initializes register variables. Inline
assembly which follows might trigger compiler to generate memory access
for "stack" argument (e.g. in case of S390_lowcore.nodat_stack). This
memory access produces a function call under kasan with outline
instrumentation which clobbers registers.
Switch "stack" argument in CALL_ON_STACK helper to use memory reference
constraint and perform load instead.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Currently unwinder test passes if unwinding results contain unwindme_func2
and unwindme_func1 functions.
Now that unwinder reports success upon reaching task pt_regs, check
that unwinding ended successfully in every test.
Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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unwind_for_each_frame can take at least 8 different sets of parameters.
Add a test to make sure they all are handled in a sane way.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Ilya Leoshkevich <[email protected]>
Co-developed-by: Vasily Gorbik <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Always inline get_stack_pointer() to avoid potential problems
due to compiler inlining decisions, i.e. getting stack pointer of
get_stack_pointer() itself which is later reused.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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The config option CONFIG_PCI_NR_FUNCTIONS sets a limit on the number of
PCI functions we can support. Previously on reaching this limit there
was no indication why newly attached devices are not recognized by Linux
which could be quite confusing. Thus this patch adds a pr_err() for this
case.
Reviewed-by: Peter Oberparleiter <[email protected]>
Signed-off-by: Niklas Schnelle <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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When UID checking was turned off during runtime in the underlying
hypervisor, a PCI device may be attached with the same UID. This is
already detected but happens silently. Add an error message so it can
more easily be understood why a device was not added.
Reviewed-by: Peter Oberparleiter <[email protected]>
Signed-off-by: Niklas Schnelle <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Each SBDT is located at a 4KB page and contains 512 entries.
Each entry of a SDBT points to a SDB, a 4KB page containing
sampled data. The last entry is a link to another SDBT page.
When an event is created the function sequence executed is:
__hw_perf_event_init()
+--> allocate_buffers()
+--> realloc_sampling_buffers()
+---> alloc_sample_data_block()
Both functions realloc_sampling_buffers() and
alloc_sample_data_block() allocate pages and the allocation
can fail. This is handled correctly and all allocated
pages are freed and error -ENOMEM is returned to the
top calling function. Finally the event is not created.
Once the event has been created, the amount of initially
allocated SDBT and SDB can be too low. This is detected
during measurement interrupt handling, where the amount
of lost samples is calculated. If the number of lost samples
is too high considering sampling frequency and already allocated
SBDs, the number of SDBs is enlarged during the next execution
of cpumsf_pmu_enable().
If more SBDs need to be allocated, functions
realloc_sampling_buffers()
+---> alloc-sample_data_block()
are called to allocate more pages. Page allocation may fail
and the returned error is ignored. A SDBT and SDB setup
already exists.
However the modified SDBTs and SDBs might end up in a situation
where the first entry of an SDBT does not point to an SDB,
but another SDBT, basicly an SBDT without payload.
This can not be handled by the interrupt handler, where an SDBT
must have at least one entry pointing to an SBD.
Add a check to avoid SDBTs with out payload (SDBs) when enlarging
the buffer setup.
Signed-off-by: Thomas Richter <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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The macro TEAR_REG() saves the last used SDBT address
in the perf_hw_event structure. This is also done
by function hw_reset_registers() which is a one-liner
and simply uses macro TEAR_REG(). Remove function
hw_reset_registers(), which is only used one time and use
macro TEAR_REG() instead. This macro is used throughout
the code anyway.
Signed-off-by: Thomas Richter <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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In interrupt handling the function extend_sampling_buffer()
is called after checking for a possibly extension.
This check is not necessary as the called function itself
performs this check again.
Signed-off-by: Thomas Richter <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Replace hard coded function names in debug statements
by the "%s ...", __func__ construct suggested by checkpatch.pl
script. Use consistent debug print format of the form variable
blank value. Also add leading 0x for all hex values.
Print allocated page addresses consistantly as hex numbers
with leading 0x.
Signed-off-by: Thomas Richter <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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The KASLR offset is added to vmcoreinfo in arch_crash_save_vmcoreinfo(),
so that it can be found by crash when processing kernel dumps.
However, arch_crash_save_vmcoreinfo() is called during a subsys_initcall,
so if the kernel crashes before that, we have no vmcoreinfo and no KASLR
offset.
Fix this by storing the KASLR offset in the lowcore, where the vmcore_info
pointer will be stored, and where it can be found by crash. In order to
make it distinguishable from a real vmcore_info pointer, mark it as uneven
(KASLR offset itself is aligned to THREAD_SIZE).
When arch_crash_save_vmcoreinfo() stores the real vmcore_info pointer in
the lowcore, it overwrites the KASLR offset. At that point, the KASLR
offset is not yet added to vmcoreinfo, so we also need to move the
mem_assign_absolute() behind the vmcoreinfo_append_str().
Fixes: b2d24b97b2a9 ("s390/kernel: add support for kernel address space layout randomization (KASLR)")
Cc: <[email protected]> # v5.2+
Signed-off-by: Gerald Schaefer <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Consider reaching task pt_regs graceful unwinder termination. Task
pt_regs itself never contains a valid state to which a task might return
within the kernel context (user task pt_regs is a special case). Since
we already avoid printing user task pt_regs and in most cases we don't
even bother filling task pt_regs psw and r15 with something reasonable
simply skip task pt_regs altogether. With this change unwind_error() now
accurately represent whether unwinder reached task pt_regs successfully
or failed along the way.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Add missing allocation of pt_regs at the bottom of the stack. This
makes it consistent with other stack setup cases and also what stack
unwinder expects.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Currently unwinder yields 2 entries when pt_regs are met:
sp="address of pt_regs itself" ip=pt_regs->psw
sp=pt_regs->gprs[15] ip="r14 from stack frame pointed by pt_regs->gprs[15]"
And neither of those 2 states (combination of sp and ip) ever happened.
reuse_sp has been introduced by commit a1d863ac3e10 ("s390/unwind: fix
mixing regs and sp"). reuse_sp=true makes unwinder keen to produce the
following result, when pt_regs are given (as an arg to unwind_start):
sp=pt_regs->gprs[15] ip=pt_regs->psw
sp=pt_regs->gprs[15] ip="r14 from stack frame pointed by pt_regs->gprs[15]"
The first state is an actual state in which a task was when pt_regs were
collected. The second state is marked unreliable and is for debugging
purposes to cover the case when a task has been interrupted in between
stack frame allocation and writing back_chain - in this case r14 might
show an actual caller.
Make unwinder behaviour enabled via reuse_sp=true default and drop the
special case handling.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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If unwinder is looking at pt_regs which is not on stack then something
went wrong and an error has to be reported rather than successful
unwinding termination.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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CALL_ON_STACK is intended to be used for temporary stack switching with
potential return to the caller.
When CALL_ON_STACK is misused to switch from nodat stack to task stack
back_chain information would later lead stack unwinder from task stack into
(per cpu) nodat stack which is reused for other purposes. This would
yield confusing unwinding result or errors.
To avoid that introduce CALL_ON_STACK_NORETURN to be used instead. It
makes sure that back_chain is zeroed and unwinder finishes gracefully
ending up at task pt_regs.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Currently CALL_ON_STACK saves r15 as back_chain in the first stack frame of
the stack we about to switch to. But if a function which uses CALL_ON_STACK
calls other function it allocates a stack frame for a callee. In this
case r15 is pointing to a callee stack frame and not a stack frame of
function itself. This results in dummy unwinding entry with random
sp and ip values.
Introduce and utilize current_frame_address macro to get an address of
actual function stack frame.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Avoid mixture of task == NULL and task == current meaning the same
thing and simply always initialize task with current in unwind_start.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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Make sure preemption is disabled when temporary switching to nodat
stack with CALL_ON_STACK helper, because nodat stack is per cpu.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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disabled_wait uses _THIS_IP_ and assumes that compiler would inline it.
Make sure this assumption is always correct by utilizing __always_inline.
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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getcpu reads the required values for cpu and node with two
instructions. This might lead to an inconsistent result if user space
gets preempted and migrated to a different CPU between the two
instructions.
Fix this by using just a single instruction to read both values at
once.
This is currently rather a theoretical bug, since there is no real
NUMA support available (except for NUMA emulation).
Reviewed-by: Christian Borntraeger <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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When a secondary CPU is brought up it must initialize its control
registers. CPU A which triggers that a secondary CPU B is brought up
stores its control register contents into the lowcore of new CPU B,
which then loads these values on startup.
This is problematic in various ways: the control register which
contains the home space ASCE will correctly contain the kernel ASCE;
however control registers for primary and secondary ASCEs are
initialized with whatever values were present in CPU A.
Typically:
- the primary ASCE will contain the user process ASCE of the process
that triggered onlining of CPU B.
- the secondary ASCE will contain the percpu VDSO ASCE of CPU A.
Due to lazy ASCE handling we may also end up with other combinations.
When then CPU B switches to a different process (!= idle) it will
fixup the primary ASCE. However the problem is that the (wrong) ASCE
from CPU A was loaded into control register 1: as soon as an ASCE is
attached (aka loaded) a CPU is free to generate TLB entries using that
address space.
Even though it is very unlikey that CPU B will actually generate such
entries, this could result in TLB entries of the address space of the
process that ran on CPU A. These entries shouldn't exist at all and
could cause problems later on.
Furthermore the secondary ASCE of CPU B will not be updated correctly.
This means that processes may see wrong results or even crash if they
access VDSO data on CPU B. The correct VDSO ASCE will eventually be
loaded on return to user space as soon as the kernel executed a call
to strnlen_user or an atomic futex operation on CPU B.
Fix both issues by intializing the to be loaded control register
contents with the correct ASCEs and also enforce (re-)loading of the
ASCEs upon first context switch and return to user space.
Fixes: 0aaba41b58bc ("s390: remove all code using the access register mode")
Cc: [email protected] # v4.15+
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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This patch introduces support for a new architectured reply
code 0x8B indicating that a hypervisor layer (if any) has
rejected an ap message.
Linux may run as a guest on top of a hypervisor like zVM
or KVM. So the crypto hardware seen by the ap bus may be
restricted by the hypervisor for example only a subset like
only clear key crypto requests may be supported. Other
requests will be filtered out - rejected by the hypervisor.
The new reply code 0x8B will appear in such cases and needs
to get recognized by the ap bus and zcrypt device driver zoo.
Signed-off-by: Harald Freudenberger <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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On s390 bpf_get_stack_raw_tp() returns 0 entries for both kernel and
user stacks. While there is no practical unwinding solution for userspace
on s390 at this moment, there certainly is a kernel unwinder. However,
it is not properly integrated with BPF.
In order to start unwinding, bpf_get_stack_raw_tp() obtains the current
kernel register values using perf_fetch_caller_regs(), which is not
implemented for s390. The actual unwinding then happens by passing those
registers to perf_callchain_kernel().
Implement perf_arch_fetch_caller_regs() for s390, where
__builtin_frame_address(0) points to back_chain.
Signed-off-by: Ilya Leoshkevich <[email protected]>
Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
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system_call assembly code always pushes pointer to struct pt_regs as the
last additional parameter for all system calls. The only user of this
feature is xtensa_rt_sigreturn.
Avoid this special case. Define xtensa_rt_sigreturn as accepting no
argiments. Use current_pt_regs to get pointer to struct pt_regs in
xtensa_rt_sigreturn. Don't pass additional parameter from system_call
code.
Signed-off-by: Max Filippov <[email protected]>
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Don't overwrite return value if system call was cancelled at entry by
ptrace. Return status code from do_syscall_trace_enter so that
pt_regs::syscall doesn't need to be changed to skip syscall.
Signed-off-by: Max Filippov <[email protected]>
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system_call saves and restores syscall number across system call to make
clone and execv entry and exit tracing match. This complicates things
when syscall code may be changed by ptrace.
Preserve syscall code in copy_thread and start_thread directly instead of
doing tricks in system_call.
Signed-off-by: Max Filippov <[email protected]>
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Some versions of iproute2 will output more than one line per entry, which
will cause the test to fail, like:
TEST: ipv6: list and flush cached exceptions [FAIL]
can't list cached exceptions
That happens, for example, with iproute2 4.15.0. When using the -oneline
option, this will work just fine:
TEST: ipv6: list and flush cached exceptions [ OK ]
This also works just fine with a more recent version of iproute2, like
5.4.0.
For some reason, two lines are printed for the IPv4 test no matter what
version of iproute2 is used. Use the same -oneline parameter there instead
of counting the lines twice.
Fixes: b964641e9925 ("selftests: pmtu: Make list_flush_ipv6_exception test more demanding")
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
Acked-by: Stefano Brivio <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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- robustification of tablet mode support in google-whiskers
driver (Dmitry Torokhov)
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- Support for Logitech G15 (Hans de Goede)
- silencing of non-informative error flow in dmesg from
logitechi-hiddpp (Hans de Goede)
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- typo fix (Geert Uytterhoeven)
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