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twx-linux/lib
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Thomas Gleixner 723aca2085 mm/scatterlist: replace the !preemptible warning in sg_miter_stop() 
sg_miter_stop() checks for disabled preemption before unmapping a page
via kunmap_atomic().  The kernel doc mentions under context that
preemption must be disabled if SG_MITER_ATOMIC is set.

There is no active requirement for the caller to have preemption
disabled before invoking sg_mitter_stop().  The sg_mitter_*()
implementation itself has no such requirement.

In fact, preemption is disabled by kmap_atomic() as part of
sg_miter_next() and remains disabled as long as there is an active
SG_MITER_ATOMIC mapping.  This is a consequence of kmap_atomic() and not
a requirement for sg_mitter_*() itself.

The user chooses SG_MITER_ATOMIC because it uses the API in a context
where blocking is not possible or blocking is possible but he chooses a
lower weight mapping which is not available on all CPUs and so it might
need less overhead to setup at a price that now preemption will be
disabled.

The kmap_atomic() implementation on PREEMPT_RT does not disable
preemption.  It simply disables CPU migration to ensure that the task
remains on the same CPU while the caller remains preemptible.  This in
turn triggers the warning in sg_miter_stop() because preemption is
allowed.

The PREEMPT_RT and !PREEMPT_RT implementation of kmap_atomic() disable
pagefaults as a requirement.  It is sufficient to check for this instead
of disabled preemption.

Check for disabled pagefault handler in the SG_MITER_ATOMIC case.
Remove the "preemption disabled" part from the kernel doc as the
sg_milter*() implementation does not care.

[bigeasy@linutronix.de: commit description]

Link: https://lkml.kernel.org/r/20211015211409.cqopacv3pxdwn2ty@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 10:02:50 -08:00
..
842
crypto crypto: arm64/sm4-ce - Make dependent on sm4 library instead of sm4-generic 2021-07-30 10:58:30 +08:00
dim
fonts lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
kunit kunit: fix reference count leak in kfree_at_end 2021-10-01 13:49:38 -06:00
livepatch
lz4 lz4_decompress: declare LZ4_decompress_safe_withPrefix64k static 2021-07-01 11:06:05 -07:00
lzo
math math: make RATIONAL tristate 2021-09-08 11:50:26 -07:00
mpi lib/mpi: use kcalloc in mpi_resize 2021-08-12 19:17:00 +08:00
pldmfw lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
raid6
reed_solomon lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
vdso lib/vdso: Add vdso_data pointer as input to __arch_get_timens_vdso_data() 2021-04-14 23:04:44 +10:00
xz lib/decompressors: fix spelling mistakes 2021-07-01 11:06:05 -07:00
zlib_deflate
zlib_dfltcc
zlib_inflate lib/zlib_inflate/inffast: check config in C to avoid unused function warning 2021-09-24 16:13:35 -07:00
zstd lib/decompressors: fix spelling mistakes 2021-07-01 11:06:05 -07:00
.gitignore .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
argv_split.c
ashldi3.c
ashrdi3.c
asn1_decoder.c
asn1_encoder.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
assoc_array.c
atomic64_test.c
atomic64.c locking/atomic: atomic64: support ARCH_ATOMIC 2021-05-26 13:20:50 +02:00
audit.c
bcd.c
bch.c lib/bch.c: fix a typo in the file bch.c 2021-05-06 19:24:12 -07:00
bitfield_kunit.c
bitmap.c bitmap: extend comment to bitmap_print_bitmask/list_to_buf 2021-08-13 10:27:50 +02:00
bitrev.c
bootconfig.c memblock: use memblock_free for freeing virtual pointers 2021-11-06 13:30:41 -07:00
bsearch.c
btree.c
bucket_locks.c
bug.c bug: Assign values once in bug_get_file_line() 2021-04-01 09:54:37 +01:00
build_OID_registry
buildid.c kdump: use vmlinux_build_id to simplify 2021-07-08 11:48:22 -07:00
bust_spinlocks.c
check_signature.c
checksum.c
clz_ctz.c
clz_tab.c
cmdline_kunit.c lib/cmdline_kunit: Remove a cast which are no-longer required 2021-06-23 16:41:41 -06:00
cmdline.c lib/cmdline: Export next_arg() for being used in modules 2021-05-05 16:07:40 +02:00
cmpdi2.c
compat_audit.c
cpu_rmap.c
cpumask.c memblock: use memblock_free for freeing virtual pointers 2021-11-06 13:30:41 -07:00
crc4.c
crc7.c
crc8.c lib: crc8: pointer to data block should be const 2021-05-06 19:24:12 -07:00
crc16.c
crc32.c
crc32defs.h
crc32test.c
crc64.c lib: crc64: fix kernel-doc warning 2021-06-05 08:58:12 -07:00
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
ctype.c
debug_info.c isystem: ship and use stdarg.h 2021-08-19 09:02:55 +09:00
debug_locks.c locking/lockdep: Improve noinstr vs errors 2021-06-22 13:56:43 +02:00
debugobjects.c debugobjects: Make them PREEMPT_RT aware 2021-08-13 10:07:44 +02:00
dec_and_lock.c
decompress_bunzip2.c lib/decompressors: fix spelling mistakes 2021-07-01 11:06:05 -07:00
decompress_inflate.c
decompress_unlz4.c lib/decompress_unlz4.c: correctly handle zero-padding around initrds. 2021-07-01 11:06:06 -07:00
decompress_unlzma.c lib: fix inconsistent indenting in process_bit1() 2021-05-06 19:24:12 -07:00
decompress_unlzo.c lib/decompressors: remove set but not used variabled 'level' 2021-07-01 11:06:06 -07:00
decompress_unxz.c lib/decompressors: fix spelling mistakes 2021-07-01 11:06:05 -07:00
decompress_unzstd.c lib/decompressors: fix spelling mistakes 2021-07-01 11:06:05 -07:00
decompress.c
devmem_is_allowed.c lib: use PFN_PHYS() in devmem_is_allowed() 2021-08-13 14:09:32 -10:00
devres.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
digsig.c
dump_stack.c lib/dump_stack: correct kernel-doc notation 2021-09-08 11:50:26 -07:00
dynamic_debug.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
dynamic_queue_limits.c
earlycpio.c lib: remove "expecting prototype" kernel-doc warnings 2021-04-16 16:10:37 -07:00
errname.c
error-inject.c
errseq.c
extable.c
fault-inject-usercopy.c
fault-inject.c
fdt_addresses.c
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_bit_benchmark.c
find_bit.c lib: add fast path for find_first_*_bit() and find_last_bit() 2021-05-06 19:24:12 -07:00
flex_proportions.c
gen_crc32table.c
gen_crc64table.c
genalloc.c lib/genalloc: add parameter description to fix doc compile warning 2021-05-06 19:24:12 -07:00
generic-radix-tree.c
glob.c
globtest.c
hexdump.c
hweight.c
idr.c
inflate.c
interval_tree_test.c
interval_tree.c
iomap_copy.c
iomap.c
iommu-helper.c
iov_iter.c iov_iter: add helper to save iov_iter state 2021-09-14 08:12:18 -06:00
irq_poll.c
irq_regs.c
is_single_threaded.c
kasprintf.c isystem: ship and use stdarg.h 2021-08-19 09:02:55 +09:00
Kconfig asm-generic changes for 5.15 2021-09-01 15:13:02 -07:00
Kconfig.debug mm/memory_hotplug: remove CONFIG_MEMORY_HOTPLUG_SPARSE 2021-11-06 13:30:42 -07:00
Kconfig.kasan kasan: fix Kconfig check of CC_HAS_WORKING_NOSANITIZE_ADDRESS 2021-09-24 16:13:34 -07:00
Kconfig.kcsan kcsan: Make strict mode imply interruptible watchers 2021-07-20 13:49:44 -07:00
Kconfig.kfence kfence: default to dynamic branch instead of static keys mode 2021-11-06 13:30:43 -07:00
Kconfig.kgdb
Kconfig.ubsan ubsan: remove overflow checks 2021-02-26 09:41:05 -08:00
kfifo.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
klist.c
kobject_uevent.c kobject_uevent: remove warning in init_uevent_argv() 2021-04-10 11:09:41 +02:00
kobject.c
kstrtox.c Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
kstrtox.h lib: vsprintf: Fix handling of number field widths in vsscanf 2021-05-19 15:05:11 +02:00
libcrc32c.c
linear_ranges.c lib: add linear range get selector within 2021-08-13 18:37:38 +02:00
list_debug.c
list_sort.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
list-test.c
llist.c
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-rtmutex.h
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c lockdep/selftest: Remove wait-type RCU_CALLBACK tests 2021-06-22 16:42:08 +02:00
lockref.c
logic_iomem.c lib/logic_iomem: fix sparse warnings 2021-08-26 22:28:02 +02:00
logic_pio.c PCI: Fix pci_register_io_range() memory leak 2021-02-17 17:31:06 -06:00
lru_cache.c lib: remove "expecting prototype" kernel-doc warnings 2021-04-16 16:10:37 -07:00
lshrdi3.c
Makefile bitfield: build kunit tests without structleak plugin 2021-10-06 17:53:54 -06:00
memcat_p.c
memory-notifier-error-inject.c
memregion.c
memweight.c
muldi3.c
net_utils.c
netdev-notifier-error-inject.c
nlattr.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
nmi_backtrace.c lib/nmi_backtrace: Serialize even messages about idle CPUs 2021-07-30 09:25:34 +02:00
nodemask.c
notifier-error-inject.c
notifier-error-inject.h
objagg.c
of-reconfig-notifier-error-inject.c
oid_registry.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
once.c once: Fix panic when module unload 2021-08-08 13:00:20 +01:00
packing.c net: update NXP copyright text 2021-09-17 13:52:17 +01:00
parman.c lib: remove "expecting prototype" kernel-doc warnings 2021-04-16 16:10:37 -07:00
parser.c kernel.h: split out kstrtox() and simple_strtox() to a separate header 2021-07-01 11:06:05 -07:00
pci_iomap.c pci_iounmap'2: Electric Boogaloo: try to make sense of it all 2021-09-19 17:13:35 -07:00
percpu_counter.c lib/percpu_counter: tame kernel-doc compile warning 2021-05-06 19:24:12 -07:00
percpu_test.c
percpu-refcount.c percpu_ref: Don't opencode percpu_ref_is_dying 2021-05-13 03:27:38 +00:00
plist.c
pm-notifier-error-inject.c
radix-tree.c lib: remove "expecting prototype" kernel-doc warnings 2021-04-16 16:10:37 -07:00
random32.c
ratelimit.c
rbtree_test.c
rbtree.c
refcount.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
rhashtable.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
sbitmap.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
scatterlist.c mm/scatterlist: replace the !preemptible warning in sg_miter_stop() 2021-11-09 10:02:50 -08:00
seq_buf.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
sg_pool.c lib/scatterlist: Fix wrong update of orig_nents 2021-08-24 19:52:40 -03:00
sg_split.c
sha1.c
show_mem.c
siphash.c
slub_kunit.c mm/slub, kunit: add a KUnit test for SLUB debugging functionality 2021-06-29 10:53:46 -07:00
smp_processor_id.c lib/smp_processor_id: Use is_percpu_thread() instead of nr_cpus_allowed 2021-05-19 10:51:40 +02:00
sort.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
stackdepot.c lib, stackdepot: add helper to print stack entries into buffer 2021-11-09 10:02:50 -08:00
stmp_device.c
string_helpers.c string_helpers: Escape double quotes in escape_special 2021-07-19 11:39:28 +02:00
string.c string: improve default out-of-line memcmp() implementation 2021-08-30 07:50:56 -07:00
strncpy_from_user.c
strnlen_user.c
syscall.c sched: Change task_struct::state 2021-06-18 11:43:09 +02:00
test_bitmap.c lib: test_bitmap: add bitmap_print_bitmask/list_to_buf test cases 2021-08-13 10:27:49 +02:00
test_bitops.c lib/test: fix spelling mistakes 2021-07-08 11:48:20 -07:00
test_bits.c
test_blackhole_dev.c
test_bpf.c bpf: Refactor BPF_PROG_RUN into a function 2021-08-17 00:45:07 +02:00
test_debug_virtual.c
test_firmware.c firmware: replace HOTPLUG with UEVENT in FW_ACTION defines 2021-05-13 16:14:45 +02:00
test_fpu.c
test_free_pages.c
test_hash.c
test_hexdump.c
test_hmm_uapi.h mm: selftests for exclusive device memory 2021-07-01 11:06:03 -07:00
test_hmm.c lib/test_hmm: remove set but unused page variable 2021-07-15 10:13:49 -07:00
test_ida.c
test_kasan_module.c kasan: test: bypass __alloc_size checks 2021-11-06 13:30:33 -07:00
test_kasan.c kasan: test: bypass __alloc_size checks 2021-11-06 13:30:33 -07:00
test_kmod.c lib/test: fix spelling mistakes 2021-07-08 11:48:20 -07:00
test_linear_ranges.c
test_list_sort.c lib/test: convert lib/test_list_sort.c to use KUnit 2021-06-25 11:31:03 -06:00
test_lockup.c lib/test_lockup: Adapt to changed variables 2021-08-17 19:05:33 +02:00
test_memcat_p.c
test_meminit.c
test_min_heap.c
test_module.c
test_objagg.c
test_overflow.c
test_parman.c
test_printf.c Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
test_rhashtable.c rhashtable: avoid -Wrestrict warning on overlapping sprintf output 2021-03-24 15:16:09 -07:00
test_scanf.c lib/test_scanf: split up number parsing test routines 2021-09-06 11:04:03 -07:00
test_siphash.c
test_sort.c lib/test: convert test_sort.c to use KUnit 2021-09-08 11:50:26 -07:00
test_stackinit.c lib/test_stackinit: Add assigned initializers 2021-08-22 00:21:36 -07:00
test_static_key_base.c
test_static_keys.c
test_string.c lib/test_string.c: allow module removal 2021-07-01 11:06:05 -07:00
test_strscpy.c
test_sysctl.c
test_ubsan.c ubsan: remove overflow checks 2021-02-26 09:41:05 -08:00
test_user_copy.c
test_uuid.c
test_vmalloc.c lib/test_vmalloc.c: use swap() to make code cleaner 2021-11-06 13:30:37 -07:00
test_xarray.c XArray: Fix splitting to non-zero orders 2021-03-30 13:42:33 -04:00
test-kstrtox.c
test-string_helpers.c string_helpers: Escape double quotes in escape_special 2021-07-19 11:39:28 +02:00
textsearch.c
timerqueue.c rbtree, timerqueue: Use rb_add_cached() 2021-02-17 14:08:01 +01:00
ts_bm.c
ts_fsm.c
ts_kmp.c
ubsan.c kunit: ubsan integration 2021-08-13 13:19:06 -06:00
ubsan.h
ucmpdi2.c
ucs2_string.c
usercopy.c
uuid.c
vsprintf.c lib: uninline simple_strntoull() as well 2021-11-09 10:02:50 -08:00
win_minmax.c
xarray.c XArray: Fix splitting to non-zero orders 2021-03-30 13:42:33 -04:00
xxhash.c