Michael Ellerman [Thu, 24 Aug 2023 06:42:10 +0000 (16:42 +1000)]
powerpc: Hide empty pt_regs at base of the stack
A thread started via eg. user_mode_thread() runs in the kernel to begin
with and then may later return to userspace. While it's running in the
kernel it has a pt_regs at the base of its kernel stack, but that
pt_regs is all zeroes.
If the thread oopses in that state, it leads to an ugly stack trace with
a big block of zero GPRs, as reported by Joel:
The all-zero pt_regs looks ugly and conveys no useful information, other
than its presence. So detect that case and just show the presence of the
frame by printing the interrupt marker, eg:
To avoid ever suppressing a valid pt_regs make sure the pt_regs has a
zero MSR and TRAP value, and is located at the very base of the stack.
Fixes: 6895dfc04741 ("powerpc: copy_thread fill in interrupt frame marker and back chain") Reported-by: Joel Stanley <joel@jms.id.au> Reported-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230824064210.907266-1-mpe@ellerman.id.au
Benjamin Gray [Wed, 11 Oct 2023 05:37:09 +0000 (16:37 +1100)]
powerpc: Cast away __iomem in low level IO routines
Sparse reports dereferencing an __iomem pointer. These routines
are clearly low level handlers for IO memory, so force cast away
the __iomem annotation to tell sparse the dereferences are safe.
Benjamin Gray [Wed, 11 Oct 2023 05:37:08 +0000 (16:37 +1100)]
powerpc/uaccess: Cast away __user annotation after verification
Sparse reports dereference of a __user pointer. copy_mc_to_user() takes
a __user pointer, verifies it, then calls the generic copy routine
copy_mc_generic().
As we have verified the pointer, cast out the __user annotation when
passing to copy_mc_generic().
Benjamin Gray [Wed, 11 Oct 2023 05:37:07 +0000 (16:37 +1100)]
powerpc/opal: Annotate out param endianness
Sparse reports an endian mismatch with args to opal_int_get_xirr().
Checking the skiboot source[1] shows the function takes a __be32*
(as expected), so update the function declaration to reflect this.
Benjamin Gray [Wed, 11 Oct 2023 05:37:05 +0000 (16:37 +1100)]
powerpc: Annotate endianness of various variables and functions
Sparse reports several endianness warnings on variables and functions
that are consistently treated as big endian. There are no
multi-endianness shenanigans going on here so fix these low hanging
fruit up in one patch.
All changes are just type annotations; no endianness switching
operations are introduced by this patch.
Benjamin Gray [Wed, 11 Oct 2023 05:37:04 +0000 (16:37 +1100)]
powerpc: Remove extern from function implementations
Sparse reports several function implementations annotated with extern.
This is clearly incorrect, likely just copied from an actual extern
declaration in another file.
Benjamin Gray [Wed, 11 Oct 2023 05:37:03 +0000 (16:37 +1100)]
powerpc: Use NULL instead of 0 for null pointers
Sparse reports several uses of 0 for pointer arguments and comparisons.
Replace with NULL to better convey the intent. Remove entirely if a
comparison to follow the kernel style of implicit boolean conversions.
Benjamin Gray [Wed, 11 Oct 2023 05:37:02 +0000 (16:37 +1100)]
powerpc: Explicitly reverse bytes when checking for byte reversal
Sparse reports an invalid endian cast here. The code is written for
big endian platforms, so le32_to_cpu() acts as a byte reversal.
This file is checked by sparse on a little endian build though, so
replace the reverse function with the dedicated swab32() function to
better express the intent of the code.
Benjamin Gray [Wed, 11 Oct 2023 05:37:00 +0000 (16:37 +1100)]
powerpc/xive: Fix endian conversion size
Sparse reports a size mismatch in the endian swap. The Opal
implementation[1] passes the value as a __be64, and the receiving
variable out_qsize is a u64, so the use of be32_to_cpu() appears to be
an error.
Introduce PAGE_EXECONLY_X macro which provides exec-only rights.
The _X may be seen as redundant with the EXECONLY but it helps
keep consistency, all macros having the EXEC right have _X.
And put it next to PAGE_NONE as PAGE_EXECONLY_X is
somehow PAGE_NONE + EXEC just like all other SOMETHING_X are
just SOMETHING + EXEC.
On book3s/64 PAGE_EXECONLY becomes PAGE_READONLY_X.
On book3s/64, as PAGE_EXECONLY is only valid for Radix add
VM_READ flag in vm_get_page_prot() for non-Radix.
And update access_error() so that a non exec fault on a VM_EXEC only
mapping is always invalid, even when the underlying layer don't
always generate a fault for that.
For 8xx, set PAGE_EXECONLY_X as _PAGE_NA | _PAGE_EXEC.
For others, only set it as just _PAGE_EXEC
With that change, 8xx, e500 and 44x fully honor execute-only
protection.
On 40x that is a partial implementation of execute-only. The
implementation won't be complete because once a TLB has been loaded
via the Instruction TLB miss handler, it will be possible to read
the page. But at least it can't be read unless it is executed first.
On 603 MMU, TLB missed are handled by SW and there are separate
DTLB and ITLB. Execute-only is therefore now supported by not loading
DTLB when read access is not permitted.
On hash (604) MMU it is more tricky because hash table is common to
load/store and execute. Nevertheless it is still possible to check
whether _PAGE_READ is set before loading hash table for a load/store
access. At least it can't be read unless it is executed first.
powerpc/32s: Introduce _PAGE_READ and remove _PAGE_USER
On 603 MMU, TLB missed are handled by SW and there are separated
DTLB and ITLB. It is therefore possible to implement execute-only
protection by not loading DTLB when read access is not permitted.
To do that, _PAGE_READ flag is needed but there is no bit available
for it in PTE. On the other hand the only real use of _PAGE_USER is
to implement PAGE_NONE by clearing _PAGE_USER.
As _PAGE_NONE can also be implemented by clearing _PAGE_READ, remove
_PAGE_USER and add _PAGE_READ. Then use the virtual address to know
whether user rights or kernel rights are to be used.
With that change, 603 MMU now honors execute-only protection.
For hash (604) MMU it is more tricky because hash table is common to
load/store and execute. Nevertheless it is still possible to check
whether _PAGE_READ is set before loading hash table for a load/store
access. At least it can't be read unless it is executed first.
powerpc/32s: Add _PAGE_WRITE to supplement _PAGE_RW
Several places, _PAGE_RW maps to write permission and don't
always imply read. To make it more clear, do as book3s/64 in
commit c7d54842deb1 ("powerpc/mm: Use _PAGE_READ to indicate
Read access") and use _PAGE_WRITE when more relevant.
For the time being _PAGE_WRITE is equivalent to _PAGE_RW but that
will change when _PAGE_READ gets added in following patches.
powerpc/40x: Introduce _PAGE_READ and remove _PAGE_USER
_PAGE_USER is used to select the zone. Today zone 0 is kernel
and zone 1 is user.
To implement _PAGE_NONE, _PAGE_USER is cleared, leading to no access
for user but kernel still has access to the page so it's possible for
a user application to write in that page by using a kernel function
as trampoline.
What is really wanted is to have user rights on pages below TASK_SIZE
and no user rights on pages above TASK_SIZE. Use zones for that.
There are 16 zones so lets use the 4 upper address bits to set the
zone and declare zone rights based on TASK_SIZE.
Then drop _PAGE_USER and reuse it as _PAGE_READ that will be checked
in Data TLB miss handler. That will properly handle PAGE_NONE for
both kernel and user.
In addition, it partially implements execute-only right. The
implementation won't be complete because once a TLB has been loaded
via the Instruction TLB miss handler, it will be possible to read
the page. But at least it can't be read unless it is executed first.
powerpc/44x: Introduce _PAGE_READ and remove _PAGE_USER
44x MMU has 6 page protection bits:
- R, W, X for supervisor
- R, W, X for user
It means that it can support X without R.
To do that, _PAGE_READ flag is needed but there is no bit available
for it in PTE. On the other hand the only real use of _PAGE_USER is
to implement PAGE_NONE by clearing _PAGE_USER.
As _PAGE_NONE can also be implemented by clearing _PAGE_READ,
remove _PAGE_USER and add _PAGE_READ. In order to insert bits in
one go during TLB miss, move _PAGE_ACCESSED and put _PAGE_READ
just after _PAGE_DIRTY so that _PAGE_DIRTY is copied into SW and
_PAGE_READ into SR at once.
With that change, 44x now also honors execute-only protection.
powerpc/e500: Introduce _PAGE_READ and remove _PAGE_USER
e500 MMU has 6 page protection bits:
- R, W, X for supervisor
- R, W, X for user
It means that it can support X without R.
To do that, _PAGE_READ flag is needed.
With 32 bits PTE there is no bit available for it in PTE. On the
other hand the only real use of _PAGE_USER is to implement PAGE_NONE
by clearing _PAGE_USER. As _PAGE_NONE can also be implemented by
clearing _PAGE_READ, remove _PAGE_USER and add _PAGE_READ. Move
_PAGE_PRESENT into bit 30 so that _PAGE_READ can match SR bit.
With 64 bits PTE _PAGE_USER is already the combination of SR and UR
so all we need to do is to rename it _PAGE_READ.
powerpc/nohash: Add _PAGE_WRITE to supplement _PAGE_RW
Several places, _PAGE_RW maps to write permission and don't
always imply read. To make it more clear, do as book3s/64 in
commit c7d54842deb1 ("powerpc/mm: Use _PAGE_READ to indicate
Read access") and use _PAGE_WRITE when more relevant.
For the time being _PAGE_WRITE is equivalent to _PAGE_RW but that
will change when _PAGE_READ gets added in following patches.
powerpc: Refactor permission masks used for __P/__S table and kernel memory flags
Prepare a common version of the permission masks that will be based
on _PAGE_NA, _PAGE_RO, _PAGE_ROX, _PAGE_RW, _PAGE_RWX that will be
defined in platform specific headers in later patches.
Put them in a new header pgtable-masks.h which will be included by
platforms.
And prepare a common version of flags used for mapping kernel memory
that will be based on _PAGE_RO, _PAGE_ROX, _PAGE_RW, _PAGE_RWX that
will be defined in platform specific headers.
Put them in unless _PAGE_KERNEL_RO is already defined so that platform
specific definitions can be dismantled one by one.
Commit b6cb20fdc273 ("powerpc/book3e: Fix set_memory_x() and
set_memory_nx()") implemented a more elaborated version of
pte_mkwrite() suitable for both kernel and user pages. That was
needed because set_memory_x() was using pte_mkwrite(). But since
commit a4c182ecf335 ("powerpc/set_memory: Avoid spinlock recursion
in change_page_attr()") pte_mkwrite() is not used anymore by
set_memory_x() so pte_mkwrite() can be simplified as it is only
used for user pages.
nohash/32 version of __ptep_set_access_flags() does the same
as nohash/64 version, the only difference is that nohash/32
version is more complete and uses pte_update().
Remove ptep_test_and_clear_young() macro, make
__ptep_test_and_clear_young() common to nohash/32 and nohash/64
and change it to become ptep_test_and_clear_young()
Deduplicate following helpers that are identical on
nohash/32 and nohash/64:
pte_mkwrite_novma()
pte_mkdirty()
pte_mkyoung()
pte_wrprotect()
pte_mkexec()
pte_young()
Nicholas Piggin [Mon, 16 Oct 2023 12:43:00 +0000 (22:43 +1000)]
powerpc/qspinlock: Fix stale propagated yield_cpu
yield_cpu is a sample of a preempted lock holder that gets propagated
back through the queue. Queued waiters use this to yield to the
preempted lock holder without continually sampling the lock word (which
would defeat the purpose of MCS queueing by bouncing the cache line).
The problem is that yield_cpu can become stale. It can take some time to
be passed down the chain, and if any queued waiter gets preempted then
it will cease to propagate the yield_cpu to later waiters.
This can result in yielding to a CPU that no longer holds the lock,
which is bad, but particularly if it is currently in H_CEDE (idle),
then it appears to be preempted and some hypervisors (PowerVM) can
cause very long H_CONFER latencies waiting for H_CEDE wakeup. This
results in latency spikes and hard lockups on oversubscribed
partitions with lock contention.
This is a minimal fix. Before yielding to yield_cpu, sample the lock
word to confirm yield_cpu is still the owner, and bail out of it is not.
Thanks to a bunch of people who reported this and tracked down the
exact problem using tracepoints and dispatch trace logs.
Fixes: 28db61e207ea ("powerpc/qspinlock: allow propagation of yield CPU down the queue") Cc: stable@vger.kernel.org # v6.2+ Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reported-by: Laurent Dufour <ldufour@linux.ibm.com> Reported-by: Shrikanth Hegde <sshegde@linux.vnet.ibm.com> Debugged-by: "Nysal Jan K.A" <nysal@linux.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Shrikanth Hegde <sshegde@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231016124305.139923-2-npiggin@gmail.com
Michael Ellerman [Tue, 17 Oct 2023 12:15:27 +0000 (23:15 +1100)]
powerpc/64s/radix: Don't warn on copros in radix__tlb_flush()
Sachin reported a warning when running the inject-ra-err selftest:
# selftests: powerpc/mce: inject-ra-err
Disabling lock debugging due to kernel taint
MCE: CPU19: machine check (Severe) Real address Load/Store (foreign/control memory) [Not recovered]
MCE: CPU19: PID: 5254 Comm: inject-ra-err NIP: [0000000010000e48]
MCE: CPU19: Initiator CPU
MCE: CPU19: Unknown
------------[ cut here ]------------
WARNING: CPU: 19 PID: 5254 at arch/powerpc/mm/book3s64/radix_tlb.c:1221 radix__tlb_flush+0x160/0x180
CPU: 19 PID: 5254 Comm: inject-ra-err Kdump: loaded Tainted: G M E 6.6.0-rc3-00055-g9ed22ae6be81 #4
Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1030.20 (NH1030_058) hv:phyp pSeries
...
NIP radix__tlb_flush+0x160/0x180
LR radix__tlb_flush+0x104/0x180
Call Trace:
radix__tlb_flush+0xf4/0x180 (unreliable)
tlb_finish_mmu+0x15c/0x1e0
exit_mmap+0x1a0/0x510
__mmput+0x60/0x1e0
exit_mm+0xdc/0x170
do_exit+0x2bc/0x5a0
do_group_exit+0x4c/0xc0
sys_exit_group+0x28/0x30
system_call_exception+0x138/0x330
system_call_vectored_common+0x15c/0x2ec
And bisected it to commit e43c0a0c3c28 ("powerpc/64s/radix: combine
final TLB flush and lazy tlb mm shootdown IPIs"), which added a warning
in radix__tlb_flush() if mm->context.copros is still elevated.
However it's possible for the copros count to be elevated if a process
exits without first closing file descriptors that are associated with a
copro, eg. VAS.
If the process exits with a VAS file still open, the release callback
is queued up for exit_task_work() via:
exit_files()
put_files_struct()
close_files()
filp_close()
fput()
And called via:
exit_task_work()
____fput()
__fput()
file->f_op->release(inode, file)
coproc_release()
vas_user_win_ops->close_win()
vas_deallocate_window()
mm_context_remove_vas_window()
mm_context_remove_copro()
But that is after exit_mm() has been called from do_exit() and triggered
the warning.
Fix it by dropping the warning, and always calling __flush_all_mm().
In the normal case of no copros, that will result in a call to
_tlbiel_pid(mm->context.id, RIC_FLUSH_ALL) just as the current code
does.
If the copros count is elevated then it will cause a global flush, which
should flush translations from any copros. Note that the process table
entry was cleared in arch_exit_mmap(), so copros should not be able to
fetch any new translations.
Fixes: e43c0a0c3c28 ("powerpc/64s/radix: combine final TLB flush and lazy tlb mm shootdown IPIs") Reported-by: Sachin Sant <sachinp@linux.ibm.com> Closes: https://lore.kernel.org/all/A8E52547-4BF1-47CE-8AEA-BC5A9D7E3567@linux.ibm.com/ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Sachin Sant <sachinp@linux.ibm.com> Link: https://msgid.link/20231017121527.1574104-1-mpe@ellerman.id.au
Several of the powerpc defconfigs previously set the
ARCH_FORCE_MAX_ORDER value to 12, via the definition in
arch/powerpc/configs/fsl-emb-nonhw.config, used by:
The problem is in ret_from_syscall where the check for
icache_44x_need_flush is done. When the flush is needed the code jumps
out-of-line to do the flush, and then intends to jump back to continue
the syscall return.
However the branch back to label 1b doesn't return to the correct
location, instead branching back just prior to the return to userspace,
causing bogus register values to be used by the rfi.
The breakage was introduced by commit 6f76a01173cc
("powerpc/syscall: implement system call entry/exit logic in C for PPC32") which
inadvertently removed the "1" label and reused it elsewhere.
Fix it by adding named local labels in the correct locations. Note that
the return label needs to be outside the ifdef so that CONFIG_PPC_47x=n
compiles.
PowerPC has a 'btext' font used for the console which is almost identical
to the shared font_sun8x16, so use it rather than duplicating the data.
They were actually identical until about a decade ago when
commit bcfbeecea11c ("drivers: console: font_: Change a glyph from
"broken bar" to "vertical line"")
which changed the | in the shared font to be a solid
bar rather than a broken bar. That's the only difference.
This was originally spotted by the PMF source code analyser, which
noticed that sparc does the same thing with the same data, and they
also share a bunch of functions to manipulate the data. I've previously
posted a near identical patch for sparc.
Tested very lightly with a boot without FS in qemu.
powerpc/pseries: Remove unused r0 in the hcall tracing code
In the plpar_hcall trace code, currently we use r0
to store the value of r4. But this value is not
used subsequently in the code. Hence remove this unused
save to r0 in plpar_hcall and plpar_hcall9
powerpc/pseries: Fix STK_PARAM access in the hcall tracing code
In powerpc pseries system, below behaviour is observed while
enabling tracing on hcall:
# cd /sys/kernel/debug/tracing/
# cat events/powerpc/hcall_exit/enable
0
# echo 1 > events/powerpc/hcall_exit/enable
# ls
-bash: fork: Bad address
Above is from power9 lpar with latest kernel. Past this, softlockup
is observed. Initially while attempting via perf_event_open to
use "PERF_TYPE_TRACEPOINT", kernel panic was observed.
Kernel attempted to read user page (8) - exploit attempt? (uid: 0)
BUG: Kernel NULL pointer dereference on read at 0x00000008
Faulting instruction address: 0xc0000000004c2814
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: nfnetlink bonding tls rfkill sunrpc dm_service_time dm_multipath pseries_rng xts vmx_crypto xfs libcrc32c sd_mod t10_pi crc64_rocksoft crc64 sg ibmvfc scsi_transport_fc ibmveth dm_mirror dm_region_hash dm_log dm_mod fuse
CPU: 0 PID: 1431 Comm: login Not tainted 6.4.0+ #1
Hardware name: IBM,8375-42A POWER9 (raw) 0x4e0202 0xf000005 of:IBM,FW950.30 (VL950_892) hv:phyp pSeries
NIP page_remove_rmap+0x44/0x320
LR wp_page_copy+0x384/0xec0
Call Trace:
0xc00000001416e400 (unreliable)
wp_page_copy+0x384/0xec0
__handle_mm_fault+0x9d4/0xfb0
handle_mm_fault+0xf0/0x350
___do_page_fault+0x48c/0xc90
hash__do_page_fault+0x30/0x70
do_hash_fault+0x1a4/0x330
data_access_common_virt+0x198/0x1f0
--- interrupt: 300 at 0x7fffae971abc
git bisect tracked this down to below commit:
'commit baa49d81a94b ("powerpc/pseries: hvcall stack frame overhead")'
This commit changed STACK_FRAME_OVERHEAD (112 ) to
STACK_FRAME_MIN_SIZE (32 ) since 32 bytes is the minimum size
for ELFv2 stack. With the latest kernel, when running on ELFv2,
STACK_FRAME_MIN_SIZE is used to allocate stack size.
During plpar_hcall_trace, first call is made to HCALL_INST_PRECALL
which saves the registers and allocates new stack frame. In the
plpar_hcall_trace code, STK_PARAM is accessed at two places.
1. To save r4: std r4,STK_PARAM(R4)(r1)
2. To access r4 back: ld r12,STK_PARAM(R4)(r1)
HCALL_INST_PRECALL precall allocates a new stack frame. So all
the stack parameter access after the precall, needs to be accessed
with +STACK_FRAME_MIN_SIZE. So the store instruction should be:
std r4,STACK_FRAME_MIN_SIZE+STK_PARAM(R4)(r1)
If the "std" is not updated with STACK_FRAME_MIN_SIZE, we will
end up with overwriting stack contents and cause corruption.
But instead of updating 'std', we can instead remove it since
HCALL_INST_PRECALL already saves it to the correct location.
similarly load instruction should be:
ld r12,STACK_FRAME_MIN_SIZE+STK_PARAM(R4)(r1)
Fix the load instruction to correctly access the stack parameter
with +STACK_FRAME_MIN_SIZE and remove the store of r4 since the
precall saves it correctly.
Michael Ellerman [Thu, 21 Sep 2023 07:26:10 +0000 (17:26 +1000)]
selftests/powerpc: Fix emit_tests to work with run_kselftest.sh
In order to use run_kselftest.sh the list of tests must be emitted to
populate kselftest-list.txt.
The powerpc Makefile is written to use EMIT_TESTS. But support for
EMIT_TESTS was dropped in commit d4e59a536f50 ("selftests: Use runner.sh
for emit targets"). Although prior to that commit a548de0fe8e1
("selftests: lib.mk: add test execute bit check to EMIT_TESTS") had
already broken run_kselftest.sh for powerpc due to the executable check
using the wrong path.
It can be fixed by replacing the EMIT_TESTS definitions with actual
emit_tests rules in the powerpc Makefiles. This makes run_kselftest.sh
able to run powerpc tests:
$ cd linux
$ export ARCH=powerpc
$ export CROSS_COMPILE=powerpc64le-linux-gnu-
$ make headers
$ make -j -C tools/testing/selftests install
$ grep -c "^powerpc" tools/testing/selftests/kselftest_install/kselftest-list.txt
182
The changes to copy_thread() made in commit eed7c420aac7 ("powerpc:
copy_thread differentiate kthreads and user mode threads") inadvertently
broke arch_stack_walk_reliable() because it has knowledge of the stack
layout.
Fix it by changing the condition to match the new logic in
copy_thread(). The changes make the comments about the stack layout
incorrect, rather than rephrasing them just refer the reader to
copy_thread().
Also the comment about the stack backchain is no longer true, since
commit edbd0387f324 ("powerpc: copy_thread add a back chain to the
switch stack frame"), so remove that as well.
Fixes: eed7c420aac7 ("powerpc: copy_thread differentiate kthreads and user mode threads") Reported-by: Joe Lawrence <joe.lawrence@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230921232441.1181843-1-mpe@ellerman.id.au
Peter Lafreniere [Mon, 18 Sep 2023 17:56:43 +0000 (17:56 +0000)]
powerpc/configs: Remove ReiserFS from defconfig
ReiserFS has been deprecated for a year and a half, yet is still built
as part of a defconfig kernel.
According to commit eb103a51640e ("reiserfs: Deprecate reiserfs"), the
filesystem is slated to be removed in 2025. Remove it from the defconfig
profiles now, as part of its deprecation process.
powerpc: Replace GPL 2.0+ README.legal boilerplate with SPDX
Upstream Linux never had a "README.legal" file, but it was present
in early source releases of Linux/m68k. It contained a simple copyright
notice and a link to a version of the "COPYING" file that predated the
addition of the "only valid GPL version is v2" clause.
Get rid of the references to non-existent files by replacing the
boilerplate with SPDX license identifiers.
Benjamin Gray [Fri, 15 Sep 2023 03:46:04 +0000 (13:46 +1000)]
powerpc/dexcr: Move HASHCHK trap handler
Syzkaller reported a sleep in atomic context bug relating to the HASHCHK
handler logic:
BUG: sleeping function called from invalid context at arch/powerpc/kernel/traps.c:1518
in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 25040, name: syz-executor
preempt_count: 0, expected: 0
RCU nest depth: 0, expected: 0
no locks held by syz-executor/25040.
irq event stamp: 34
hardirqs last enabled at (33): [<c000000000048b38>] prep_irq_for_enabled_exit arch/powerpc/kernel/interrupt.c:56 [inline]
hardirqs last enabled at (33): [<c000000000048b38>] interrupt_exit_user_prepare_main+0x148/0x600 arch/powerpc/kernel/interrupt.c:230
hardirqs last disabled at (34): [<c00000000003e6a4>] interrupt_enter_prepare+0x144/0x4f0 arch/powerpc/include/asm/interrupt.h:176
softirqs last enabled at (0): [<c000000000281954>] copy_process+0x16e4/0x4750 kernel/fork.c:2436
softirqs last disabled at (0): [<0000000000000000>] 0x0
CPU: 15 PID: 25040 Comm: syz-executor Not tainted 6.5.0-rc5-00001-g3ccdff6bb06d #3
Hardware name: IBM,9105-22A POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1040.00 (NL1040_021) hv:phyp pSeries
Call Trace:
[c0000000a8247ce0] [c00000000032b0e4] __might_resched+0x3b4/0x400 kernel/sched/core.c:10189
[c0000000a8247d80] [c0000000008c7dc8] __might_fault+0xa8/0x170 mm/memory.c:5853
[c0000000a8247dc0] [c00000000004160c] do_program_check+0x32c/0xb20 arch/powerpc/kernel/traps.c:1518
[c0000000a8247e50] [c000000000009b2c] program_check_common_virt+0x3bc/0x3c0
To determine if a trap was caused by a HASHCHK instruction, we inspect
the user instruction that triggered the trap. However this may sleep
if the page needs to be faulted in (get_user_instr() reaches
__get_user(), which calls might_fault() and triggers the bug message).
Move the HASHCHK handler logic to after we allow IRQs, which is fine
because we are only interested in HASHCHK if it's a user space trap.
It used to be impossible to select CONFIG_CPM2 without selecting
CONFIG_FSL_SOC at the same time because CONFIG_CPM2 was dependent
on CONFIG_8260 and CONFIG_8260 was selecting CONFIG_FSL_SOC.
But after commit eb5aa2137275 ("powerpc/82xx: Remove CONFIG_8260
and CONFIG_8272") CONFIG_CPM2 depends on CONFIG_PPC_82xx instead
but CONFIG_PPC_82xx doesn't directly selects CONFIG_FSL_SOC.
Fix it by forcing CONFIG_PPC_82xx to select CONFIG_FSL_SOC just
like already done by PPC_8xx, PPC_MPC512x, PPC_83xx, PPC_86xx.
Reported-by: Randy Dunlap <rdunlap@infradead.org> Fixes: eb5aa2137275 ("powerpc/82xx: Remove CONFIG_8260 and CONFIG_8272") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Tested-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/7ab513546148ebe33ddd4b0ea92c7bfd3cce3ad7.1694705016.git.christophe.leroy@csgroup.eu
powerpc: Fix build issue with LD_DEAD_CODE_DATA_ELIMINATION and FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
We recently added support for -fpatchable-function-entry and it is
enabled by default on ppc32 (ppc64 needs gcc v13.1.0). When building the
kernel for ppc32 and also enabling CONFIG_LD_DEAD_CODE_DATA_ELIMINATION,
we see the below build error with older gcc versions:
powerpc-linux-gnu-ld: init/main.o(__patchable_function_entries): error: need linked-to section for --gc-sections
This error is thrown since __patchable_function_entries section would be
garbage collected with --gc-sections since it does not reference any
other kept sections. This has subsequently been fixed with:
https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=b7d072167715829eed0622616f6ae0182900de3e
Disable LD_DEAD_CODE_DATA_ELIMINATION for gcc versions before v11.1.0 if
using -fpatchable-function-entry to avoid this bug.
Fixes: 0f71dcfb4aef ("powerpc/ftrace: Add support for -fpatchable-function-entry") Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N Rao <naveen@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230913134129.2782088-1-naveen@kernel.org
Benjamin Gray [Tue, 29 Aug 2023 06:34:57 +0000 (16:34 +1000)]
powerpc/watchpoints: Annotate atomic context in more places
It can be easy to miss that the notifier mechanism invokes the callbacks
in an atomic context, so add some comments to that effect on the two
handlers we register here.
Benjamin Gray [Tue, 29 Aug 2023 06:34:56 +0000 (16:34 +1000)]
powerpc/watchpoint: Disable pagefaults when getting user instruction
This is called in an atomic context, so is not allowed to sleep if a
user page needs to be faulted in and has nowhere it can be deferred to.
The pagefault_disabled() function is documented as preventing user
access methods from sleeping.
In practice the page will be mapped in nearly always because we are
reading the instruction that just triggered the watchpoint trap.
Benjamin Gray [Tue, 29 Aug 2023 06:34:55 +0000 (16:34 +1000)]
powerpc/watchpoints: Disable preemption in thread_change_pc()
thread_change_pc() uses CPU local data, so must be protected from
swapping CPUs while it is reading the breakpoint struct.
The error is more noticeable after 1e60f3564bad ("powerpc/watchpoints:
Track perf single step directly on the breakpoint"), which added an
unconditional __this_cpu_read() call in thread_change_pc(). However the
existing __this_cpu_read() that runs if a breakpoint does need to be
re-inserted has the same issue.
Kajol Jain [Fri, 25 Aug 2023 05:56:01 +0000 (11:26 +0530)]
powerpc/perf/hv-24x7: Update domain value check
Valid domain value is in range 1 to HV_PERF_DOMAIN_MAX. Current code has
check for domain value greater than or equal to HV_PERF_DOMAIN_MAX. But
the check for domain value 0 is missing.
Fix this issue by adding check for domain value 0.
Before:
# ./perf stat -v -e hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/ sleep 1
Using CPUID 00800200
Control descriptor is not initialized
Error:
The sys_perf_event_open() syscall returned with 5 (Input/output error) for
event (hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/).
/bin/dmesg | grep -i perf may provide additional information.
Result from dmesg:
[ 37.819387] hv-24x7: hcall failed: [0 0x60040000 0x100 0] => ret
0xfffffffffffffffc (-4) detail=0x2000000 failing ix=0
After:
# ./perf stat -v -e hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/ sleep 1
Using CPUID 00800200
Control descriptor is not initialized
Warning:
hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/ event is not supported by the kernel.
failed to read counter hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/
Hari Bathini [Tue, 12 Sep 2023 08:29:50 +0000 (13:59 +0530)]
powerpc/fadump: make is_kdump_kernel() return false when fadump is active
Currently, is_kdump_kernel() returns true in crash dump capture kernel
for both kdump and fadump crash dump capturing methods, as both these
methods set elfcorehdr_addr. Some restrictions enforced for crash dump
capture kernel, based on is_kdump_kernel(), are specifically meant for
kdump case and not desirable for fadump - eg. IO queues restriction in
device drivers. So, define is_kdump_kernel() to return false when f/w
assisted dump is active.
Hari Bathini [Tue, 12 Sep 2023 08:29:49 +0000 (13:59 +0530)]
vmcore: remove dependency with is_kdump_kernel() for exporting vmcore
Currently, is_kdump_kernel() returns true when elfcorehdr_addr is set.
While elfcorehdr_addr is set for kexec based kernel dump mechanism,
alternate dump capturing methods like fadump [1] also set it to export
the vmcore. Since, is_kdump_kernel() is used to restrict resources in
crash dump capture kernel and such restrictions may not be desirable
for fadump, allow is_kdump_kernel() to be defined differently for such
scenarios. With this, is_kdump_kernel() could be false while vmcore is
usable. So, remove unnecessary dependency with is_kdump_kernel(), for
exporting vmcore.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Acked-by: Baoquan He <bhe@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230912082950.856977-1-hbathini@linux.ibm.com
Presently, while reading a vmcore, makedumpfile uses
`cur_cpu_spec.mmu_features` to decide whether the crashed system had
RADIX MMU or not.
Currently, makedumpfile fails to get the `cur_cpu_spec` symbol (unless
a vmlinux is passed with the `-x` flag to makedumpfile), and hence
assigns offsets and shifts (such as pgd_offset_l4) incorrecly considering
MMU to be hash MMU.
Add `cur_cpu_spec` symbol and offset of `mmu_features` in the
`cpu_spec` struct, to VMCOREINFO, so that the symbol address and offset
is accessible to makedumpfile, without needing the vmlinux file
Signed-off-by: Aditya Gupta <adityag@linux.ibm.com> Reported-by: Sachin Sant <sachinp@linux.ibm.com> Tested-by: Sachin Sant <sachinp@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230911091409.415662-1-adityag@linux.ibm.com
Merge tag 'x86-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Misc fixes:
- Fix an UV boot crash
- Skip spurious ENDBR generation on _THIS_IP_
- Fix ENDBR use in putuser() asm methods
- Fix corner case boot crashes on 5-level paging
- and fix a false positive WARNING on LTO kernels"
* tag 'x86-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/purgatory: Remove LTO flags
x86/boot/compressed: Reserve more memory for page tables
x86/ibt: Avoid duplicate ENDBR in __put_user_nocheck*()
x86/ibt: Suppress spurious ENDBR
x86/platform/uv: Use alternate source for socket to node data
Merge tag 'sched-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
"Fix a performance regression on large SMT systems, an Intel SMT4
balancing bug, and a topology setup bug on (Intel) hybrid processors"
* tag 'sched-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sched: Restore the SD_ASYM_PACKING flag in the DIE domain
sched/fair: Fix SMT4 group_smt_balance handling
sched/fair: Optimize should_we_balance() for large SMT systems
The choose_32_64() macros were added to deal with an odd inconsistency
between the 32-bit and 64-bit layout of 'struct stat' way back when in
commit a52dd971f947 ("vfs: de-crapify "cp_new_stat()" function").
Then a decade later Mikulas noticed that said inconsistency had been a
mistake in the early x86-64 port, and shouldn't have existed in the
first place. So commit 932aba1e1690 ("stat: fix inconsistency between
struct stat and struct compat_stat") removed the uses of the helpers.
Merge tag '6.6-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull smb client fixes from Steve French:
"Three small SMB3 client fixes, one to improve a null check and two
minor cleanups"
* tag '6.6-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
smb3: fix some minor typos and repeated words
smb3: correct places where ENOTSUPP is used instead of preferred EOPNOTSUPP
smb3: move server check earlier when setting channel sequence number
Merge tag 'ext4_for_linus-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"Regression and bug fixes for ext4"
* tag 'ext4_for_linus-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix rec_len verify error
ext4: do not let fstrim block system suspend
ext4: move setting of trimmed bit into ext4_try_to_trim_range()
jbd2: Fix memory leak in journal_init_common()
jbd2: Remove page size assumptions
buffer: Make bh_offset() work for compound pages
This causes WARNING from kexec_purgatory_setup_sechdrs():
WARNING: CPU: 26 PID: 110894 at kernel/kexec_file.c:919
kexec_load_purgatory+0x37f/0x390
Fix this by disabling LTO for purgatory.
[ AFAICT, x86 is the only arch that supports LTO and purgatory. ]
We could also fix this with an explicit linker script to rejoin .text.*
sections back into .text. However, given the benefit of LTOing purgatory
is small, simply disable the production of more .text.* sections for now.
Fixes: b33fff07e3e3 ("x86, build: allow LTO to be selected") Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20230914170138.995606-1-song@kernel.org
x86/boot/compressed: Reserve more memory for page tables
The decompressor has a hard limit on the number of page tables it can
allocate. This limit is defined at compile-time and will cause boot
failure if it is reached.
The kernel is very strict and calculates the limit precisely for the
worst-case scenario based on the current configuration. However, it is
easy to forget to adjust the limit when a new use-case arises. The
worst-case scenario is rarely encountered during sanity checks.
In the case of enabling 5-level paging, a use-case was overlooked. The
limit needs to be increased by one to accommodate the additional level.
This oversight went unnoticed until Aaron attempted to run the kernel
via kexec with 5-level paging and unaccepted memory enabled.
Update wost-case calculations to include 5-level paging.
To address this issue, let's allocate some extra space for page tables.
128K should be sufficient for any use-case. The logic can be simplified
by using a single value for all kernel configurations.
[ Also add a warning, should this memory run low - by Dave Hansen. ]
Fixes: 34bbb0009f3b ("x86/boot/compressed: Enable 5-level paging during decompression stage") Reported-by: Aaron Lu <aaron.lu@intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230915070221.10266-1-kirill.shutemov@linux.intel.com
Merge tag 'kbuild-fixes-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- Fix kernel-devel RPM and linux-headers Deb package
- Fix too long argument list error in 'make modules_install'
* tag 'kbuild-fixes-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: avoid long argument lists in make modules_install
kbuild: fix kernel-devel RPM package and linux-headers Deb package
Commit 408579cd627a ("mm: Update do_vmi_align_munmap() return
semantics") seems to have updated one of the callers of do_vmi_munmap()
incorrectly: it used to check for the error case (which didn't
change: negative means error).
That commit changed the check to the success case (which did change:
before that commit, 0 was success, and 1 was "success and lock
downgraded". After the change, it's always 0 for success, and the lock
will have been released if requested).
This didn't change any actual VM behavior _except_ for memory accounting
when 'VM_ACCOUNT' was set on the vma. Which made the wrong return value
test fairly subtle, since everything continues to work.
Or rather - it continues to work but the "Committed memory" accounting
goes all wonky (Committed_AS value in /proc/meminfo), and depending on
settings that then causes problems much much later as the VM relies on
bogus statistics for its heuristics.
Revert that one line of the change back to the original logic.
Fixes: 408579cd627a ("mm: Update do_vmi_align_munmap() return semantics") Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de> Reported-bisected-and-tested-by: Michael Labiuk <michael.labiuk@virtuozzo.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Link: https://lore.kernel.org/all/1694366957@msgid.manchmal.in-ulm.de/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"16 small(ish) fixes all in drivers.
The major fixes are in pm8001 (fixes MSI-X issue going back to its
origin), the qla2xxx endianness fix, which fixes a bug on big endian
and the lpfc ones which can cause an oops on module removal without
them"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: lpfc: Prevent use-after-free during rmmod with mapped NVMe rports
scsi: lpfc: Early return after marking final NLP_DROPPED flag in dev_loss_tmo
scsi: lpfc: Fix the NULL vs IS_ERR() bug for debugfs_create_file()
scsi: target: core: Fix target_cmd_counter leak
scsi: pm8001: Setup IRQs on resume
scsi: pm80xx: Avoid leaking tags when processing OPC_INB_SET_CONTROLLER_CONFIG command
scsi: pm80xx: Use phy-specific SAS address when sending PHY_START command
scsi: ufs: core: Poll HCS.UCRDY before issuing a UIC command
scsi: ufs: core: Move __ufshcd_send_uic_cmd() outside host_lock
scsi: qedf: Add synchronization between I/O completions and abort
scsi: target: Replace strlcpy() with strscpy()
scsi: qla2xxx: Fix NULL vs IS_ERR() bug for debugfs_create_dir()
scsi: qla2xxx: Use raw_smp_processor_id() instead of smp_processor_id()
scsi: qla2xxx: Correct endianness for rqstlen and rsplen
scsi: ppa: Fix accidentally reversed conditions for 16-bit and 32-bit EPP
scsi: megaraid_sas: Fix deadlock on firmware crashdump
Merge tag 'ata-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata
Pull ata fixes from Damien Le Moal:
- Fix link power management transitions to disallow unsupported states
(Niklas)
- A small string handling fix for the sata_mv driver (Christophe)
- Clear port pending interrupts before reset, as per AHCI
specifications (Szuying).
Followup fixes for this one are to not clear ATA_PFLAG_EH_PENDING in
ata_eh_reset() to allow EH to continue on with other actions recorded
with error interrupts triggered before EH completes. And an
additional fix to avoid thawing a port twice in EH (Niklas)
- Small code style fixes in the pata_parport driver to silence the
build bot as it keeps complaining about bad indentation (me)
- A fix for the recent CDL code to avoid fetching sense data for
successful commands when not necessary for correct operation (Niklas)
* tag 'ata-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
ata: libata-core: fetch sense data for successful commands iff CDL enabled
ata: libata-eh: do not thaw the port twice in ata_eh_reset()
ata: libata-eh: do not clear ATA_PFLAG_EH_PENDING in ata_eh_reset()
ata: pata_parport: Fix code style issues
ata: libahci: clear pending interrupt status
ata: sata_mv: Fix incorrect string length computation in mv_dump_mem()
ata: libata: disallow dev-initiated LPM transitions to unsupported states
Merge tag 'usb-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fix from Greg KH:
"Here is a single USB fix for a much-reported regression for 6.6-rc1.
It resolves a crash in the typec debugfs code for many systems. It's
been in linux-next with no reported issues, and many people have
reported it resolving their problem with 6.6-rc1"
* tag 'usb-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: typec: ucsi: Fix NULL pointer dereference
Merge tag 'driver-core-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here is a single driver core fix for a much-reported-by-sysbot issue
that showed up in 6.6-rc1. It's been submitted by many people, all in
the same way, so it obviously fixes things for them all.
Also in here is a single documentation update adding riscv to the
embargoed hardware document in case there are any future issues with
that processor family.
Both of these have been in linux-next with no reported problems"
* tag 'driver-core-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
Documentation: embargoed-hardware-issues.rst: Add myself for RISC-V
driver core: return an error when dev_set_name() hasn't happened
Merge tag 'char-misc-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc fix from Greg KH:
"Here is a single patch for 6.6-rc2 that reverts a 6.5 change for the
comedi subsystem that has ended up being incorrect and caused drivers
that were working for people to be unable to be able to be selected to
build at all.
To fix this, the Kconfig change needs to be reverted and a future set
of fixes for the ioport dependancies will show up in 6.7-rc1 (there's
no rush for them.)
This has been in linux-next with no reported issues"
* tag 'char-misc-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
Revert "comedi: add HAS_IOPORT dependencies"
Merge tag 'i2c-for-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang:
"The main thing is the removal of 'probe_new' because all i2c client
drivers are converted now. Thanks Uwe, this marks the end of a long
conversion process.
Other than that, we have a few Kconfig updates and driver bugfixes"
* tag 'i2c-for-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: cadence: Fix the kernel-doc warnings
i2c: aspeed: Reset the i2c controller when timeout occurs
i2c: I2C_MLXCPLD on ARM64 should depend on ACPI
i2c: Make I2C_ATR invisible
i2c: Drop legacy callback .probe_new()
w1: ds2482: Switch back to use struct i2c_driver's .probe()
ata: libata-core: fetch sense data for successful commands iff CDL enabled
Currently, we fetch sense data for a _successful_ command if either:
1) Command was NCQ and ATA_DFLAG_CDL_ENABLED flag set (flag
ATA_DFLAG_CDL_ENABLED will only be set if the Successful NCQ command
sense data supported bit is set); or
2) Command was non-NCQ and regular sense data reporting is enabled.
This means that case 2) will trigger for a non-NCQ command which has
ATA_SENSE bit set, regardless if CDL is enabled or not.
This decision was by design. If the device reports that it has sense data
available, it makes sense to fetch that sense data, since the sk/asc/ascq
could be important information regardless if CDL is enabled or not.
However, the fetching of sense data for a successful command is done via
ATA EH. Considering how intricate the ATA EH is, we really do not want to
invoke ATA EH unless absolutely needed.
Before commit 18bd7718b5c4 ("scsi: ata: libata: Handle completion of CDL
commands using policy 0xD") we never fetched sense data for successful
commands.
In order to not invoke the ATA EH unless absolutely necessary, even if the
device claims support for sense data reporting, only fetch sense data for
successful (NCQ and non-NCQ commands) commands that are using CDL.
[Damien] Modified the check to test the qc flag ATA_QCFLAG_HAS_CDL
instead of the device support for CDL, which is implied for commands
using CDL.
Fixes: 3ac873c76d79 ("ata: libata-core: fix when to fetch sense data for successful commands") Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com> Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
projects / thirdparty / kernel / linux.git / log
