Commit Graph

137778 Commits

Author SHA1 Message Date
Wenchao Hao
ad515cada7 scsi: iscsi: Add helper functions to manage iscsi_cls_conn
- iscsi_alloc_conn(): Allocate and initialize iscsi_cls_conn

 - iscsi_add_conn(): Expose iscsi_cls_conn to userspace via sysfs

 - iscsi_remove_conn(): Remove iscsi_cls_conn from sysfs

Link: https://lore.kernel.org/r/20220310015759.3296841-2-haowenchao@huawei.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Wenchao Hao <haowenchao@huawei.com>
Signed-off-by: Wu Bo <wubo40@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-03-15 00:19:50 -04:00
Stephen Boyd
45ceaf14d5 Input: extract ChromeOS vivaldi physmap show function
Let's introduce a common library file for the physmap show function
duplicated between three different keyboard drivers. This largely copies
the code from cros_ec_keyb.c which has the most recent version of the
show function, while using the vivaldi_data struct from the hid-vivaldi
driver. This saves a small amount of space in an allyesconfig build.

$ ./scripts/bloat-o-meter vmlinux.before vmlinux.after

add/remove: 3/0 grow/shrink: 2/3 up/down: 412/-720 (-308)
Function                                     old     new   delta
vivaldi_function_row_physmap_show              -     292    +292
_sub_I_65535_1                           1057564 1057616     +52
_sub_D_65535_0                           1057564 1057616     +52
e843419@49f2_00062737_9b04                     -       8      +8
e843419@20f6_0002a34d_35bc                     -       8      +8
atkbd_parse_fwnode_data                      480     472      -8
atkbd_do_show_function_row_physmap           316      76    -240
function_row_physmap_show                    620     148    -472
Total: Before=285581925, After=285581617, chg -0.00%

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Tested-by: Stephen Boyd <swboyd@chromium.org> # coachz, wormdingler
Link: https://lore.kernel.org/r/20220228075446.466016-3-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-03-14 21:11:09 -07:00
Mingzhe Zou
d72d827f2f scsi: target: Add iscsi/cpus_allowed_list in configfs
The RX/TX threads for iSCSI connection can be scheduled to any online CPUs,
and will not be rescheduled.

When binding other heavy load threads along with iSCSI connection RX/TX
thread to the same CPU, the iSCSI performance will be worse.

Add iscsi/cpus_allowed_list in configfs. The available CPU set of iSCSI
connection RX/TX threads is allowed_cpus & online_cpus. If it is modified,
all RX/TX threads will be rescheduled.

Link: https://lore.kernel.org/r/20220301075500.14266-1-mingzhe.zou@easystack.cn
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-03-14 23:40:36 -04:00
John Garry
095478a6e5 scsi: hisi_sas: Use libsas internal abort support
Use the common libsas internal abort functionality.

In addition, this driver has special handling for internal abort timeouts -
specifically whether to reset the controller in that instance, so extend
the API for that.

Timeout is now increased to 20 * Hz from 6 * Hz.

We also retry for failure now, but this should not make a difference.

Link: https://lore.kernel.org/r/1647001432-239276-5-git-send-email-john.garry@huawei.com
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-03-14 23:33:24 -04:00
John Garry
6a91c3e315 scsi: libsas: Add sas_execute_internal_abort_dev()
Add support for a "device" variant of internal abort, which will abort all
pending I/Os for a specific device.

Link: https://lore.kernel.org/r/1647001432-239276-3-git-send-email-john.garry@huawei.com
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-03-14 23:33:23 -04:00
John Garry
5c9bf3635b scsi: libsas: Add sas_execute_internal_abort_single()
The internal abort feature is common to hisi_sas and pm8001 HBAs, and the
driver support is similar also, so add a common handler.

Two modes of operation will be supported:

 - single: Abort a single tagged command

 - device: Abort all commands associated with a specific domain device

A new protocol is added, SAS_PROTOCOL_INTERNAL_ABORT, so the common queue
command API may be re-used.

Only add "single" support as a first step.

Link: https://lore.kernel.org/r/1647001432-239276-2-git-send-email-john.garry@huawei.com
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-03-14 23:33:23 -04:00
Dmitry Torokhov
ce83563350 Merge tag 'v5.17-rc8' into next
Sync up with mainline to again get the latest changes in HID subsystem.
2022-03-14 19:14:29 -07:00
Guodong Liu
338e953f1b dt-bindings: pinctrl: mt8186: add pinctrl file and binding document
1. This patch adds pinctrl file for mt8186.
2. This patch adds mt8186 compatible node in binding document.

Signed-off-by: Guodong Liu <guodong.liu@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220216032124.28067-2-guodong.liu@mediatek.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2022-03-15 01:00:03 +01:00
Jakub Kicinski
15d703921f Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net coming late
in the 5.17-rc process:

1) Revert port remap to mitigate shadowing service ports, this is causing
   problems in existing setups and this mitigation can be achieved with
   explicit ruleset, eg.

	... tcp sport < 16386 tcp dport >= 32768 masquerade random

  This patches provided a built-in policy similar to the one described above.

2) Disable register tracking infrastructure in nf_tables. Florian reported
   two issues:

   - Existing expressions with no implemented .reduce interface
     that causes data-store on register should cancel the tracking.
   - Register clobbering might be possible storing data on registers that
     are larger than 32-bits.

   This might lead to generating incorrect ruleset bytecode. These two
   issues are scheduled to be addressed in the next release cycle.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables: disable register tracking
  Revert "netfilter: conntrack: tag conntracks picked up in local out hook"
  Revert "netfilter: nat: force port remap to prevent shadowing well-known ports"
====================

Link: https://lore.kernel.org/r/20220312220315.64531-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-14 15:51:10 -07:00
Tejun Heo
aa1b46dcdc block: fix rq-qos breakage from skipping rq_qos_done_bio()
a647a524a4 ("block: don't call rq_qos_ops->done_bio if the bio isn't
tracked") made bio_endio() skip rq_qos_done_bio() if BIO_TRACKED is not set.
While this fixed a potential oops, it also broke blk-iocost by skipping the
done_bio callback for merged bios.

Before, whether a bio goes through rq_qos_throttle() or rq_qos_merge(),
rq_qos_done_bio() would be called on the bio on completion with BIO_TRACKED
distinguishing the former from the latter. rq_qos_done_bio() is not called
for bios which wenth through rq_qos_merge(). This royally confuses
blk-iocost as the merged bios never finish and are considered perpetually
in-flight.

One reliably reproducible failure mode is an intermediate cgroup geting
stuck active preventing its children from being activated due to the
leaf-only rule, leading to loss of control. The following is from
resctl-bench protection scenario which emulates isolating a web server like
workload from a memory bomb run on an iocost configuration which should
yield a reasonable level of protection.

  # cat /sys/block/nvme2n1/device/model
  Samsung SSD 970 PRO 512GB
  # cat /sys/fs/cgroup/io.cost.model
  259:0 ctrl=user model=linear rbps=834913556 rseqiops=93622 rrandiops=102913 wbps=618985353 wseqiops=72325 wrandiops=71025
  # cat /sys/fs/cgroup/io.cost.qos
  259:0 enable=1 ctrl=user rpct=95.00 rlat=18776 wpct=95.00 wlat=8897 min=60.00 max=100.00
  # resctl-bench -m 29.6G -r out.json run protection::scenario=mem-hog,loops=1
  ...
  Memory Hog Summary
  ==================

  IO Latency: R p50=242u:336u/2.5m p90=794u:1.4m/7.5m p99=2.7m:8.0m/62.5m max=8.0m:36.4m/350m
              W p50=221u:323u/1.5m p90=709u:1.2m/5.5m p99=1.5m:2.5m/9.5m max=6.9m:35.9m/350m

  Isolation and Request Latency Impact Distributions:

                min   p01   p05   p10   p25   p50   p75   p90   p95   p99   max  mean stdev
  isol%       15.90 15.90 15.90 40.05 57.24 59.07 60.01 74.63 74.63 90.35 90.35 58.12 15.82
  lat-imp%        0     0     0     0     0  4.55 14.68 15.54 233.5 548.1 548.1 53.88 143.6

  Result: isol=58.12:15.82% lat_imp=53.88%:143.6 work_csv=100.0% missing=3.96%

The isolation result of 58.12% is close to what this device would show
without any IO control.

Fix it by introducing a new flag BIO_QOS_MERGED to mark merged bios and
calling rq_qos_done_bio() on them too. For consistency and clarity, rename
BIO_TRACKED to BIO_QOS_THROTTLED. The flag checks are moved into
rq_qos_done_bio() so that it's next to the code paths that set the flags.

With the patch applied, the above same benchmark shows:

  # resctl-bench -m 29.6G -r out.json run protection::scenario=mem-hog,loops=1
  ...
  Memory Hog Summary
  ==================

  IO Latency: R p50=123u:84.4u/985u p90=322u:256u/2.5m p99=1.6m:1.4m/9.5m max=11.1m:36.0m/350m
              W p50=429u:274u/995u p90=1.7m:1.3m/4.5m p99=3.4m:2.7m/11.5m max=7.9m:5.9m/26.5m

  Isolation and Request Latency Impact Distributions:

                min   p01   p05   p10   p25   p50   p75   p90   p95   p99   max  mean stdev
  isol%       84.91 84.91 89.51 90.73 92.31 94.49 96.36 98.04 98.71 100.0 100.0 94.42  2.81
  lat-imp%        0     0     0     0     0  2.81  5.73 11.11 13.92 17.53 22.61  4.10  4.68

  Result: isol=94.42:2.81% lat_imp=4.10%:4.68 work_csv=58.34% missing=0%

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: a647a524a4 ("block: don't call rq_qos_ops->done_bio if the bio isn't tracked")
Cc: stable@vger.kernel.org # v5.15+
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/Yi7rdrzQEHjJLGKB@slm.duckdns.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-03-14 14:23:13 -06:00
Matthew Wilcox (Oracle)
2e7e80f7e7 fs: Convert is_partially_uptodate to folios
Since the uptodate property is maintained on a per-folio basis, the
is_partially_uptodate method should also take a folio.  Fix the types
at the same time so it's clear that it returns true/false and takes
the count in bytes, not blocks.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs
2022-03-14 15:43:17 -04:00
Matthew Wilcox (Oracle)
cd1067beee buffer: Add folio_buffers()
While there is no intent to use large folios in filesystems using buffer
heads, converting the filesystems to use single-page folios is still worth
doing to remove legacy infrastructure and hidden calls to compound_head().
These helper functions are needed for that conversion to take place.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs
2022-03-14 15:43:16 -04:00
Matthew Wilcox (Oracle)
c14c6843ae fs: read_mapping_page() should take a struct file argument
While read_cache_page() takes a void *, because you can pass a
pointer to anything as the first argument of filler_t, if we
are calling read_mapping_page(), it will be passed as the first
argument of ->readpage, so we know this must be a struct file
pointer, and we should let the compiler enforce that for us.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs
2022-03-14 15:43:16 -04:00
Will Deacon
641d804157 Merge branch 'for-next/spectre-bhb' into for-next/core
Merge in the latest Spectre mess to fix up conflicts with what was
already queued for 5.18 when the embargo finally lifted.

* for-next/spectre-bhb: (21 commits)
  arm64: Do not include __READ_ONCE() block in assembly files
  arm64: proton-pack: Include unprivileged eBPF status in Spectre v2 mitigation reporting
  arm64: Use the clearbhb instruction in mitigations
  KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated
  arm64: Mitigate spectre style branch history side channels
  arm64: proton-pack: Report Spectre-BHB vulnerabilities as part of Spectre-v2
  arm64: Add percpu vectors for EL1
  arm64: entry: Add macro for reading symbol addresses from the trampoline
  arm64: entry: Add vectors that have the bhb mitigation sequences
  arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations
  arm64: entry: Allow the trampoline text to occupy multiple pages
  arm64: entry: Make the kpti trampoline's kpti sequence optional
  arm64: entry: Move trampoline macros out of ifdef'd section
  arm64: entry: Don't assume tramp_vectors is the start of the vectors
  arm64: entry: Allow tramp_alias to access symbols after the 4K boundary
  arm64: entry: Move the trampoline data page before the text page
  arm64: entry: Free up another register on kpti's tramp_exit path
  arm64: entry: Make the trampoline cleanup optional
  KVM: arm64: Allow indirect vectors to be used without SPECTRE_V3A
  arm64: spectre: Rename spectre_v4_patch_fw_mitigation_conduit
  ...
2022-03-14 19:08:31 +00:00
Will Deacon
b5ef94fb56 Merge branch 'for-next/perf' into for-next/core
* for-next/perf: (25 commits)
  perf/marvell: Fix !CONFIG_OF build for CN10K DDR PMU driver
  drivers/perf: Add Apple icestorm/firestorm CPU PMU driver
  drivers/perf: arm_pmu: Handle 47 bit counters
  arm64: perf: Consistently make all event numbers as 16-bits
  arm64: perf: Expose some Armv9 common events under sysfs
  perf/marvell: cn10k DDR perf event core ownership
  perf/marvell: cn10k DDR perfmon event overflow handling
  perf/marvell: CN10k DDR performance monitor support
  dt-bindings: perf: marvell: cn10k ddr performance monitor
  perf/arm-cmn: Update watchpoint format
  perf/arm-cmn: Hide XP PUB events for CMN-600
  perf: replace bitmap_weight with bitmap_empty where appropriate
  perf: Replace acpi_bus_get_device()
  perf/marvell_cn10k: Fix unused variable warning when W=1 and CONFIG_OF=n
  perf/arm-cmn: Make arm_cmn_debugfs static
  perf: MARVELL_CN10K_TAD_PMU should depend on ARCH_THUNDER
  perf/arm-ccn: Use platform_get_irq() to get the interrupt
  irqchip/apple-aic: Move PMU-specific registers to their own include file
  arm64: dts: apple: Add t8303 PMU nodes
  arm64: dts: apple: Add t8103 PMU interrupt affinities
  ...
2022-03-14 19:01:37 +00:00
Will Deacon
bf587af2ab Merge branch 'for-next/mte' into for-next/core
* for-next/mte:
  docs: sysfs-devices-system-cpu: document "asymm" value for mte_tcf_preferred
  arm64/mte: Remove asymmetric mode from the prctl() interface
  kasan: fix a missing header include of static_keys.h
  arm64/mte: Add userspace interface for enabling asymmetric mode
  arm64/mte: Add hwcap for asymmetric mode
  arm64/mte: Add a little bit of documentation for mte_update_sctlr_user()
  arm64/mte: Document ABI for asymmetric mode
  arm64: mte: avoid clearing PSTATE.TCO on entry unless necessary
  kasan: split kasan_*enabled() functions into a separate header
2022-03-14 19:01:23 +00:00
Will Deacon
563c463595 Merge branch 'for-next/linkage' into for-next/core
* for-next/linkage:
  arm64: module: remove (NOLOAD) from linker script
  linkage: remove SYM_FUNC_{START,END}_ALIAS()
  x86: clean up symbol aliasing
  arm64: clean up symbol aliasing
  linkage: add SYM_FUNC_ALIAS{,_LOCAL,_WEAK}()
2022-03-14 19:01:05 +00:00
Ingo Molnar
411472ae5b Merge tag 'v5.17-rc8' into irq/core, to fix conflicts
Conflicts:
	drivers/pinctrl/pinctrl-starfive.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2022-03-14 18:53:00 +01:00
Eric Dumazet
fc93db153b net: disable preemption in dev_core_stats_XXX_inc() helpers
syzbot was kind enough to remind us that dev->{tx_dropped|rx_dropped}
could be increased in process context.

BUG: using smp_processor_id() in preemptible [00000000] code: syz-executor413/3593
caller is netdev_core_stats_alloc+0x98/0x110 net/core/dev.c:10298
CPU: 1 PID: 3593 Comm: syz-executor413 Not tainted 5.17.0-rc7-syzkaller-02426-g97aeb877de7f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 check_preemption_disabled+0x16b/0x170 lib/smp_processor_id.c:49
 netdev_core_stats_alloc+0x98/0x110 net/core/dev.c:10298
 dev_core_stats include/linux/netdevice.h:3855 [inline]
 dev_core_stats_rx_dropped_inc include/linux/netdevice.h:3866 [inline]
 tun_get_user+0x3455/0x3ab0 drivers/net/tun.c:1800
 tun_chr_write_iter+0xe1/0x200 drivers/net/tun.c:2015
 call_write_iter include/linux/fs.h:2074 [inline]
 new_sync_write+0x431/0x660 fs/read_write.c:503
 vfs_write+0x7cd/0xae0 fs/read_write.c:590
 ksys_write+0x12d/0x250 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f2cf4f887e3
Code: 5d 41 5c 41 5d 41 5e e9 9b fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 55 c3 0f 1f 40 00 48 83 ec 28 48 89 54 24 18
RSP: 002b:00007ffd50dd5fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ffd50dd6000 RCX: 00007f2cf4f887e3
RDX: 000000000000002a RSI: 0000000000000000 RDI: 00000000000000c8
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd50dd5ff0 R14: 00007ffd50dd5fe8 R15: 00007ffd50dd5fe4
 </TASK>

Fixes: 625788b584 ("net: add per-cpu storage and net->core_stats")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: jeffreyji <jeffreyji@google.com>
Cc: Brian Vazquez <brianvv@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20220312214505.3294762-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-14 10:15:00 -07:00
Tudor Ambarus
ec090a0392 mtd: core: Remove partid and partname debugfs files
partid and partname debugfs files were used just by SPI NOR, but they were
replaced by sysfs entries. Since these debugfs files are no longer used in
mtd, remove dead code. The directory is kept as it is used by nandsim,
mtdswap and docg3.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220225144656.634682-1-tudor.ambarus@microchip.com
2022-03-14 17:01:58 +01:00
Jani Nikula
5f1b97cb9a x86/gpu: include drm/i915_pciids.h directly in early quirks
early-quirks.c is the only user of drm/i915_drm.h that also needs
drm/i915_pciids.h. Include the masses of PCI ID macros only where
needed.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220311100639.114685-1-jani.nikula@intel.com
2022-03-14 17:57:00 +02:00
Ville Syrjälä
2d3eec8970 drm: Add drm_mode_init()
Add a variant of drm_mode_copy() that explicitly clears out
the list head of the destination mode. Helpful to guarantee
we don't have stack garbage left in there for on-stack modes.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220218100403.7028-2-ville.syrjala@linux.intel.com
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
2022-03-14 17:36:59 +02:00
Greg Kroah-Hartman
4cc893176c Merge 5.17-rc8 into staging-next
We need the staging fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-14 15:06:38 +01:00
Omar Sandoval
dcb77a9ae8 btrfs: add definitions and documentation for encoded I/O ioctls
In order to allow sending and receiving compressed data without
decompressing it, we need an interface to write pre-compressed data
directly to the filesystem and the matching interface to read compressed
data without decompressing it. This adds the definitions for ioctls to
do that and detailed explanations of how to use them.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-03-14 13:13:51 +01:00
Omar Sandoval
f6f7a25a65 fs: export variant of generic_write_checks without iov_iter
Encoded I/O in Btrfs needs to check a write with a given logical size
without an iov_iter that matches that size (because the iov_iter we have
is for the compressed data). So, factor out the parts of
generic_write_check() that don't need an iov_iter into a new
generic_write_checks_count() function and export that.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-03-14 13:13:50 +01:00
Omar Sandoval
871129332d fs: export rw_verify_area()
I'm adding btrfs ioctls to read and write compressed data, and rather
than duplicating the checks in rw_verify_area(), let's just export it.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-03-14 13:13:50 +01:00
Josef Bacik
9c54e80ddc btrfs: add code to support the block group root
This code adds the on disk structures for the block group root, which
will hold the block group items for extent tree v2.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-03-14 13:13:48 +01:00
Josef Bacik
2c7d2a2302 btrfs: add definition for EXTENT_TREE_V2
This adds the initial definition of the EXTENT_TREE_V2 incompat feature
flag.  This also hides the support behind CONFIG_BTRFS_DEBUG.

THIS IS A IN DEVELOPMENT FORMAT CHANGE, DO NOT USE UNLESS YOU ARE A
DEVELOPER OR A TESTER.

The format is in flux and will be added in stages, any fs will need to
be re-made between updates to the format.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-03-14 13:13:48 +01:00
Vladimir Oltean
978777d0fb net: dsa: felix: configure default-prio and dscp priorities
Follow the established programming model for this driver and provide
shims in the felix DSA driver which call the implementations from the
ocelot switch lib. The ocelot switchdev driver wasn't integrated with
dcbnl due to lack of hardware availability.

The switch doesn't have any fancy QoS classification enabled by default.
The provided getters will create a default-prio app table entry of 0,
and no dscp entry. However, the getters have been made to actually
retrieve the hardware configuration rather than static values, to be
future proof in case DSA will need this information from more call paths.

For default-prio, there is a single field per port, in ANA_PORT_QOS_CFG,
called QOS_DEFAULT_VAL.

DSCP classification is enabled per-port, again via ANA_PORT_QOS_CFG
(field QOS_DSCP_ENA), and individual DSCP values are configured as
trusted or not through register ANA_DSCP_CFG (replicated 64 times).
An untrusted DSCP value falls back to other QoS classification methods.
If trusted, the selected ANA_DSCP_CFG register also holds the QoS class
in the QOS_DSCP_VAL field.

The hardware also supports DSCP remapping (DSCP value X is translated to
DSCP value Y before the QoS class is determined based on the app table
entry for Y) and DSCP packet rewriting. The dcbnl framework, for being
so flexible in other useless areas, doesn't appear to support this.
So this functionality has been left out.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-14 10:36:15 +00:00
Vladimir Oltean
47d75f7822 net: dsa: report and change port dscp priority using dcbnl
Similar to the port-based default priority, IEEE 802.1Q-2018 allows the
Application Priority Table to define QoS classes (0 to 7) per IP DSCP
value (0 to 63).

In the absence of an app table entry for a packet with DSCP value X,
QoS classification for that packet falls back to other methods (VLAN PCP
or port-based default). The presence of an app table for DSCP value X
with priority Y makes the hardware classify the packet to QoS class Y.

As opposed to the default-prio where DSA exposes only a "set" in
dsa_switch_ops (because the port-based default is the fallback, it
always exists, either implicitly or explicitly), for DSCP priorities we
expose an "add" and a "del". The addition of a DSCP entry means trusting
that DSCP priority, the deletion means ignoring it.

Drivers that already trust (at least some) DSCP values can describe
their configuration in dsa_switch_ops :: port_get_dscp_prio(), which is
called for each DSCP value from 0 to 63.

Again, there can be more than one dcbnl app table entry for the same
DSCP value, DSA chooses the one with the largest configured priority.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-14 10:36:15 +00:00
Vladimir Oltean
d538eca85c net: dsa: report and change port default priority using dcbnl
The port-based default QoS class is assigned to packets that lack a
VLAN PCP (or the port is configured to not trust the VLAN PCP),
an IP DSCP (or the port is configured to not trust IP DSCP), and packets
on which no tc-skbedit action has matched.

Similar to other drivers, this can be exposed to user space using the
DCB Application Priority Table. IEEE 802.1Q-2018 specifies in Table
D-8 - Sel field values that when the Selector is 1, the Protocol ID
value of 0 denotes the "Default application priority. For use when
application priority is not otherwise specified."

The way in which the dcbnl integration in DSA has been designed has to
do with its requirements. Andrew Lunn explains that SOHO switches are
expected to come with some sort of pre-configured QoS profile, and that
it is desirable for this to come pre-loaded into the DSA slave interfaces'
DCB application priority table.

In the dcbnl design, this is possible because calls to dcb_ieee_setapp()
can be initiated by anyone including being self-initiated by this device
driver.

However, what makes this challenging to implement in DSA is that the DSA
core manages the net_devices (effectively hiding them from drivers),
while drivers manage the hardware. The DSA core has no knowledge of what
individual drivers' QoS policies are. DSA could export to drivers a
wrapper over dcb_ieee_setapp() and these could call that function to
pre-populate the app priority table, however drivers don't have a good
moment in time to do this. The dsa_switch_ops :: setup() method gets
called before the net_devices are created (dsa_slave_create), and so is
dsa_switch_ops :: port_setup(). What remains is dsa_switch_ops ::
port_enable(), but this gets called upon each ndo_open. If we add app
table entries on every open, we'd need to remove them on close, to avoid
duplicate entry errors. But if we delete app priority entries on close,
what we delete may not be the initial, driver pre-populated entries, but
rather user-added entries.

So it is clear that letting drivers choose the timing of the
dcb_ieee_setapp() call is inappropriate. The alternative which was
chosen is to introduce hardware-specific ops in dsa_switch_ops, and
effectively hide dcbnl details from drivers as well. For pre-populating
the application table, dsa_slave_dcbnl_init() will call
ds->ops->port_get_default_prio() which is supposed to read from
hardware. If the operation succeeds, DSA creates a default-prio app
table entry. The method is called as soon as the slave_dev is
registered, but before we release the rtnl_mutex. This is done such that
user space sees the app table entries as soon as it sees the interface
being registered.

The fact that we populate slave_dev->dcbnl_ops with a non-NULL pointer
changes behavior in dcb_doit() from net/dcb/dcbnl.c, which used to
return -EOPNOTSUPP for any dcbnl operation where netdev->dcbnl_ops is
NULL. Because there are still dcbnl-unaware DSA drivers even if they
have dcbnl_ops populated, the way to restore the behavior is to make all
dcbnl_ops return -EOPNOTSUPP on absence of the hardware-specific
dsa_switch_ops method.

The dcbnl framework absurdly allows there to be more than one app table
entry for the same selector and protocol (in other words, more than one
port-based default priority). In the iproute2 dcb program, there is a
"replace" syntactical sugar command which performs an "add" and a "del"
to hide this away. But we choose the largest configured priority when we
call ds->ops->port_set_default_prio(), using __fls(). When there is no
default-prio app table entry left, the port-default priority is restored
to 0.

Link: https://patchwork.kernel.org/project/netdevbpf/patch/20210113154139.1803705-2-olteanv@gmail.com/
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-14 10:36:15 +00:00
Sebastian Andrzej Siewior
fbd9a2ceba net: Add lockdep asserts to ____napi_schedule().
____napi_schedule() needs to be invoked with disabled interrupts due to
__raise_softirq_irqoff (in order not to corrupt the per-CPU list).
____napi_schedule() needs also to be invoked from an interrupt context
so that the raised-softirq is processed while the interrupt context is
left.

Add lockdep asserts for both conditions.
While this is the second time the irq/softirq check is needed, provide a
generic lockdep_assert_softirq_will_run() which is used by both caller.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-14 10:09:28 +00:00
Ziyang Xuan
1f4a5983d6 net: macvlan: add net device refcount tracker
Add net device refcount tracker to macvlan.

Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-14 10:06:54 +00:00
Thomas Gleixner
f0fae8a0ed Merge tag 'irqchip-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core
Pull irqchip updates from Marc Zyngier:

  - Add support for the STM32MP13 variant

  - Move parent device away from struct irq_chip

  - Remove all instances of non-const strings assigned to
    struct irq_chip::name, enabling a nice cleanup for VIC and GIC)

  - Simplify the Qualcomm PDC driver

  - A bunch of SiFive PLIC cleanups

  - Add support for a new variant of the Meson GPIO block

  - Add support for the irqchip side of the Apple M1 PMU

  - Add support for the Apple M1 Pro/Max AICv2 irqchip

  - Add support for the Qualcomm MPM wakeup gadget

  - Move the Xilinx driver over to the generic irqdomain handling

  - Tiny speedup for IPIs on GICv3 systems

  - The usual odd cleanups

Link: https://lore.kernel.org/all/20220313105142.704579-1-maz@kernel.org
2022-03-14 10:23:22 +01:00
Thomas Gleixner
b166e52541 Merge tag 'timers-v5.18-rc1' of https://git.linaro.org/people/daniel.lezcano/linux into timers/core
Pull clocksource/events updates from Daniel Lezcano:

  - Fix return error code check for the timer-of layer when getting
    the base address (Guillaume Ranquet)

  - Remove MMIO dependency, add notrace annotation for sched_clock
    and increase the timer resolution for the Microchip
    PIT64b (Claudiu Beznea)

  - Convert DT bindings to yaml for the Tegra timer (David Heidelberg)

  - Fix compilation error on architecture other than ARM for the
    i.MX TPM (Nathan Chancellor)

  - Add support for the event stream scaling for 1GHz counter on
    the arch ARM timer (Marc Zyngier)

  - Support a higher number of interrupts by the Exynos MCT timer
    driver (Alim Akhtar)

  - Detect and prevent memory corruption when the specified number
    of interrupts in the DTS is greater than the array size in the
    code for the Exynos MCT timer (Krzysztof Kozlowski)

  - Fix regression from a previous errata fix on the TI DM
    timer (Drew Fustini)

  - Several fixes and code improvements for the i.MX TPM
    driver (Peng Fan)

Link: https://lore.kernel.org/all/a8cd9be9-7d70-80df-2b74-1a8226a215e1@linaro.org
2022-03-14 10:18:17 +01:00
NeilBrown
64158668ac NFS: swap IO handling is slightly different for O_DIRECT IO
1/ Taking the i_rwsem for swap IO triggers lockdep warnings regarding
   possible deadlocks with "fs_reclaim".  These deadlocks could, I believe,
   eventuate if a buffered read on the swapfile was attempted.

   We don't need coherence with the page cache for a swap file, and
   buffered writes are forbidden anyway.  There is no other need for
   i_rwsem during direct IO.  So never take it for swap_rw()

2/ generic_write_checks() explicitly forbids writes to swap, and
   performs checks that are not needed for swap.  So bypass it
   for swap_rw().

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2022-03-13 12:59:35 -04:00
NeilBrown
4dc73c6791 NFSv4: keep state manager thread active if swap is enabled
If we are swapping over NFSv4, we may not be able to allocate memory to
start the state-manager thread at the time when we need it.
So keep it always running when swap is enabled, and just signal it to
start.

This requires updating and testing the cl_swapper count on the root
rpc_clnt after following all ->cl_parent links.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2022-03-13 12:59:35 -04:00
NeilBrown
89c2be8a95 NFS: discard NFS_RPC_SWAPFLAGS and RPC_TASK_ROOTCREDS
NFS_RPC_SWAPFLAGS is only used for READ requests.
It sets RPC_TASK_SWAPPER which gives some memory-allocation priority to
requests.  This is not needed for swap READ - though it is for writes
where it is set via a different mechanism.

RPC_TASK_ROOTCREDS causes the 'machine' credential to be used.
This is not needed as the root credential is saved when the swap file is
opened, and this is used for all IO.

So NFS_RPC_SWAPFLAGS isn't needed, and as it is the only user of
RPC_TASK_ROOTCREDS, that isn't needed either.

Remove both.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2022-03-13 12:59:35 -04:00
NeilBrown
a41b05edfe SUNRPC/auth: async tasks mustn't block waiting for memory
When memory is short, new worker threads cannot be created and we depend
on the minimum one rpciod thread to be able to handle everything.  So it
must not block waiting for memory.

mempools are particularly a problem as memory can only be released back
to the mempool by an async rpc task running.  If all available workqueue
threads are waiting on the mempool, no thread is available to return
anything.

lookup_cred() can block on a mempool or kmalloc - and this can cause
deadlocks.  So add a new RPCAUTH_LOOKUP flag for async lookups and don't
block on memory.  If the -ENOMEM gets back to call_refreshresult(), wait
a short while and try again.  HZ>>4 is chosen as it is used elsewhere
for -ENOMEM retries.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2022-03-13 12:59:35 -04:00
Dave Wysochanski
b5fdf66f6e NFS: Remove remaining dfprintks related to fscache and remove NFSDBG_FSCACHE
The fscache cookie APIs including fscache_acquire_cookie() and
fscache_relinquish_cookie() now have very good tracing.  Thus,
there is no real need for dfprintks in the NFS fscache interface.

The NFS fscache interface has removed all dfprintks so remove the
NFSDBG_FSCACHE defines.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2022-03-13 12:59:35 -04:00
Arnaud Pouliquen
8109517b39 rpmsg: ctrl: Introduce new RPMSG_CREATE/RELEASE_DEV_IOCTL controls
Allow the user space application to create and release an rpmsg device
by adding RPMSG_CREATE_DEV_IOCTL and RPMSG_RELEASE_DEV_IOCTL ioctrls to
the /dev/rpmsg_ctrl interface

The RPMSG_CREATE_DEV_IOCTL Ioctl can be used to instantiate a local rpmsg
device.
Depending on the back-end implementation, the associated rpmsg driver is
probed and a NS announcement can be sent to the remote processor.

The RPMSG_RELEASE_DEV_IOCTL allows the user application to release a
rpmsg device created either by the remote processor or with the
RPMSG_CREATE_DEV_IOCTL call.
Depending on the back-end implementation, the associated rpmsg driver is
removed and a NS destroy rpmsg can be sent to the remote processor.

Suggested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220124102524.295783-12-arnaud.pouliquen@foss.st.com
2022-03-13 11:49:53 -05:00
Ritesh Harjani
8cb5a30372 ext4: convert ext4_fc_track_dentry type events to use event class
One should use DECLARE_EVENT_CLASS for similar event types instead of
defining TRACE_EVENT for each event type. This is helpful in reducing
the text section footprint for e.g. [1]

[1]: https://lwn.net/Articles/381064/

Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/a019cb46219ef4b30e4d98d7ced7d8819a2fc61d.1647057583.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-03-12 21:26:08 -05:00
Ritesh Harjani
7af1974af0 ext4: fix ext4_fc_stats trace point
ftrace's __print_symbolic() requires that any enum values used in the
symbol to string translation table be wrapped in a TRACE_DEFINE_ENUM
so that the enum value can be decoded from the ftrace ring buffer by
user space tooling.

This patch also fixes few other problems found in this trace point.
e.g. dereferencing structures in TP_printk which should not be done
at any cost.

Also to avoid checkpatch warnings, this patch removes those
whitespaces/tab stops issues.

Cc: stable@kernel.org
Fixes: aa75f4d3da ("ext4: main fast-commit commit path")
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/b4b9691414c35c62e570b723e661c80674169f9a.1647057583.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-03-12 21:26:08 -05:00
Dave Gerlach
df227dc8a6 mailbox: ti-msgmgr: Operate mailbox in polled mode during system suspend
During the system suspend path we must set all queues to operate in
polled mode as it is possible for any protocol built using this mailbox,
such as TISCI, to require communication during the no irq phase of suspend,
and we cannot rely on interrupts there.

Polled mode is implemented by allowing the mailbox user to define an
RX channel as part of the message that is sent which is what gets polled
for a response. If polled mode is enabled, this will immediately be
polled for a response at the end of the mailbox send_data op before
returning success for the data send or timing out if no response is
received.

Finally, to ensure polled mode is always enabled during system suspend,
iterate through all queues to set RX queues to polled mode during system
suspend and disable polled mode for all in the resume handler.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2022-03-12 19:33:30 -06:00
Jason A. Donenfeld
f3c2682bad random: provide notifier for VM fork
Drivers such as WireGuard need to learn when VMs fork in order to clear
sessions. This commit provides a simple notifier_block for that, with a
register and unregister function. When no VM fork detection is compiled
in, this turns into a no-op, similar to how the power notifier works.

Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-03-12 18:00:56 -07:00
Jason A. Donenfeld
5acd35487d random: replace custom notifier chain with standard one
We previously rolled our own randomness readiness notifier, which only
has two users in the whole kernel. Replace this with a more standard
atomic notifier block that serves the same purpose with less code. Also
unexport the symbols, because no modules use it, only unconditional
builtins. The only drawback is that it's possible for a notification
handler returning the "stop" code to prevent further processing, but
given that there are only two users, and that we're unexporting this
anyway, that doesn't seem like a significant drawback for the
simplification we receive here.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-03-12 18:00:56 -07:00
Jason A. Donenfeld
a4107d34f9 random: do not export add_vmfork_randomness() unless needed
Since add_vmfork_randomness() is only called from vmgenid.o, we can
guard it in CONFIG_VMGENID, similarly to how we do with
add_disk_randomness() and CONFIG_BLOCK. If we ever have multiple things
calling into add_vmfork_randomness(), we can add another shared Kconfig
symbol for that, but for now, this is good enough. Even though
add_vmfork_randomess() is a pretty small function, removing it means
that there are only calls to crng_reseed(false) and none to
crng_reseed(true), which means the compiler can constant propagate the
false, removing branches from crng_reseed() and its descendants.

Additionally, we don't even need the symbol to be exported if
CONFIG_VMGENID is not a module, so conditionalize that too.

Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-03-12 18:00:56 -07:00
Alexander Graf
d273845ecb ACPI: allow longer device IDs
We create a list of ACPI "PNP" IDs which contains _HID, _CID, and CLS
entries of the respective devices. However, when making structs for
matching, we squeeze those IDs into acpi_device_id, which only has 9
bytes space to store the identifier. The subsystem actually captures the
full length of the IDs, and the modalias has the full length, but this
struct we use for matching is limited. It originally had 16 bytes, but
was changed to only have 9 in 6543becf26 ("mod/file2alias: make
modalias generation safe for cross compiling"), presumably on the theory
that it would match the ACPI spec so it didn't matter.

Unfortunately, while most people adhere to the ACPI specs, Microsoft
decided that its VM Generation Counter device [1] should only be
identifiable by _CID with a value of "VM_Gen_Counter", which is longer
than 9 characters.

To allow device drivers to match identifiers that exceed the 9 byte
limit, this simply ups the length to 16, just like it was before the
aforementioned commit. Empirical testing indicates that this
doesn't actually increase vmlinux size on 64-bit, because the ulong in
the same struct caused there to be 7 bytes of padding anyway, and when
doing a s/M/Y/g i386_defconfig build, the bzImage only increased by
0.0055%, so negligible.

This patch is a prerequisite to add support for VMGenID in Linux, the
subsequent patch in this series. It has been confirmed to also work on
the udev/modalias side in userspace.

[1] https://download.microsoft.com/download/3/1/C/31CFC307-98CA-4CA5-914C-D9772691E214/VirtualMachineGenerationID.docx

Signed-off-by: Alexander Graf <graf@amazon.com>
Co-developed-by: Jason A. Donenfeld <Jason@zx2c4.com>
[Jason: reworked commit message a bit, went with len=16 approach.]
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-03-12 18:00:56 -07:00
Jason A. Donenfeld
ae099e8e98 random: add mechanism for VM forks to reinitialize crng
When a VM forks, we must immediately mix in additional information to
the stream of random output so that two forks or a rollback don't
produce the same stream of random numbers, which could have catastrophic
cryptographic consequences. This commit adds a simple API, add_vmfork_
randomness(), for that, by force reseeding the crng.

This has the added benefit of also draining the entropy pool and setting
its timer back, so that any old entropy that was there prior -- which
could have already been used by a different fork, or generally gone
stale -- does not contribute to the accounting of the next 256 bits.

Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jann Horn <jannh@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-03-12 18:00:56 -07:00
Jason A. Donenfeld
6f98a4bfee random: block in /dev/urandom
This topic has come up countless times, and usually doesn't go anywhere.
This time I thought I'd bring it up with a slightly narrower focus,
updated for some developments over the last three years: we finally can
make /dev/urandom always secure, in light of the fact that our RNG is
now always seeded.

Ever since Linus' 50ee7529ec ("random: try to actively add entropy
rather than passively wait for it"), the RNG does a haveged-style jitter
dance around the scheduler, in order to produce entropy (and credit it)
for the case when we're stuck in wait_for_random_bytes(). How ever you
feel about the Linus Jitter Dance is beside the point: it's been there
for three years and usually gets the RNG initialized in a second or so.

As a matter of fact, this is what happens currently when people use
getrandom(). It's already there and working, and most people have been
using it for years without realizing.

So, given that the kernel has grown this mechanism for seeding itself
from nothing, and that this procedure happens pretty fast, maybe there's
no point any longer in having /dev/urandom give insecure bytes. In the
past we didn't want the boot process to deadlock, which was
understandable. But now, in the worst case, a second goes by, and the
problem is resolved. It seems like maybe we're finally at a point when
we can get rid of the infamous "urandom read hole".

The one slight drawback is that the Linus Jitter Dance relies on random_
get_entropy() being implemented. The first lines of try_to_generate_
entropy() are:

	stack.now = random_get_entropy();
	if (stack.now == random_get_entropy())
		return;

On most platforms, random_get_entropy() is simply aliased to get_cycles().
The number of machines without a cycle counter or some other
implementation of random_get_entropy() in 2022, which can also run a
mainline kernel, and at the same time have a both broken and out of date
userspace that relies on /dev/urandom never blocking at boot is thought
to be exceedingly low. And to be clear: those museum pieces without
cycle counters will continue to run Linux just fine, and even
/dev/urandom will be operable just like before; the RNG just needs to be
seeded first through the usual means, which should already be the case
now.

On systems that really do want unseeded randomness, we already offer
getrandom(GRND_INSECURE), which is in use by, e.g., systemd for seeding
their hash tables at boot. Nothing in this commit would affect
GRND_INSECURE, and it remains the means of getting those types of random
numbers.

This patch goes a long way toward eliminating a long overdue userspace
crypto footgun. After several decades of endless user confusion, we will
finally be able to say, "use any single one of our random interfaces and
you'll be fine. They're all the same. It doesn't matter." And that, I
think, is really something. Finally all of those blog posts and
disagreeing forums and contradictory articles will all become correct
about whatever they happened to recommend, and along with it, a whole
class of vulnerabilities eliminated.

With very minimal downside, we're finally in a position where we can
make this change.

Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Guo Ren <guoren@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: David Laight <David.Laight@aculab.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-03-12 18:00:55 -07:00