Here is the big set of tty/serial driver changes for 6.10-rc1. Included
in here are:
- Usual good set of api cleanups and evolution by Jiri Slaby to make
the serial interfaces move out of the 1990's by using kfifos instead
of hand-rolling their own logic.
- 8250_exar driver updates
- max3100 driver updates
- sc16is7xx driver updates
- exar driver updates
- sh-sci driver updates
- tty ldisc api addition to help refuse bindings
- other smaller serial driver updates
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCZk4Cvg8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ymqpwCgnHU1NeBBUsvoSDOLk5oApIQ4jVgAn102jWlw
3dNDhA4i3Ay/mZdv8/Kj
=TI+P
-----END PGP SIGNATURE-----
Merge tag 'tty-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty / serial updates from Greg KH:
"Here is the big set of tty/serial driver changes for 6.10-rc1.
Included in here are:
- Usual good set of api cleanups and evolution by Jiri Slaby to make
the serial interfaces move out of the 1990's by using kfifos
instead of hand-rolling their own logic.
- 8250_exar driver updates
- max3100 driver updates
- sc16is7xx driver updates
- exar driver updates
- sh-sci driver updates
- tty ldisc api addition to help refuse bindings
- other smaller serial driver updates
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (113 commits)
serial: Clear UPF_DEAD before calling tty_port_register_device_attr_serdev()
serial: imx: Raise TX trigger level to 8
serial: 8250_pnp: Simplify "line" related code
serial: sh-sci: simplify locking when re-issuing RXDMA fails
serial: sh-sci: let timeout timer only run when DMA is scheduled
serial: sh-sci: describe locking requirements for invalidating RXDMA
serial: sh-sci: protect invalidating RXDMA on shutdown
tty: add the option to have a tty reject a new ldisc
serial: core: Call device_set_awake_path() for console port
dt-bindings: serial: brcm,bcm2835-aux-uart: convert to dtschema
tty: serial: uartps: Add support for uartps controller reset
arm64: zynqmp: Add resets property for UART nodes
dt-bindings: serial: cdns,uart: Add optional reset property
serial: 8250_pnp: Switch to DEFINE_SIMPLE_DEV_PM_OPS()
serial: 8250_exar: Keep the includes sorted
serial: 8250_exar: Make type of bit the same in exar_ee_*_bit()
serial: 8250_exar: Use BIT() in exar_ee_read()
serial: 8250_exar: Switch to use dev_err_probe()
serial: 8250_exar: Return directly from switch-cases
serial: 8250_exar: Decrease indentation level
...
-----BEGIN PGP SIGNATURE-----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=y45P
-----END PGP SIGNATURE-----
Merge tag 'printk-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek:
- Use no_printk() instead of "if (0) printk()" constructs to avoid
generating printk index for messages disabled at compile time
- Remove deprecated strncpy/strcpy from printk.c
- Remove redundant CONFIG_BASE_FULL in favor of CONFIG_BASE_SMALL
* tag 'printk-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk: cleanup deprecated uses of strncpy/strcpy
printk: Remove redundant CONFIG_BASE_FULL
printk: Change type of CONFIG_BASE_SMALL to bool
printk: Fix LOG_CPU_MAX_BUF_SHIFT when BASE_SMALL is enabled
ceph: Use no_printk() helper
dyndbg: Use *no_printk() helpers
dev_printk: Add and use dev_no_printk()
printk: Let no_printk() use _printk()
Cleanup some deprecated uses of strncpy() and strcpy() [1].
There doesn't seem to be any bugs with the current code but the
readability of this code could benefit from a quick makeover while
removing some deprecated stuff as a benefit.
The most interesting replacement made in this patch involves
concatenating "ttyS" with a digit-led user-supplied string. Instead of
doing two distinct string copies with carefully managed offsets and
lengths, let's use the more robust and self-explanatory scnprintf().
scnprintf will 1) respect the bounds of @buf, 2) null-terminate @buf, 3)
do the concatenation. This allows us to drop the manual NUL-byte assignment.
Also, since isdigit() is used about a dozen lines after the open-coded
version we'll replace it for uniformity's sake.
All the strcpy() --> strscpy() replacements are trivial as the source
strings are literals and much smaller than the destination size. No
behavioral change here.
Use the new 2-argument version of strscpy() introduced in Commit
e6584c3964 ("string: Allow 2-argument strscpy()"). However, to make
this work fully (since the size must be known at compile time), also
update the extern-qualified declaration to have the proper size
information.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90 [2]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [3]
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240429-strncpy-kernel-printk-printk-c-v1-1-4da7926d7b69@google.com
[pmladek@suse.com: Removed obsolete brackets and added empty lines.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Add a generic function console_replay_all() for replaying
the kernel log on consoles, in any context. It would allow
viewing the logs on an unresponsive terminal via sysrq.
Reuse the existing code from console_flush_on_panic() for
resetting the sequence numbers, by introducing a new helper
function __console_rewind_all(). It is safe to be called
under console_lock().
Try to acquire lock on the console subsystem without waiting.
If successful, reset the sequence number to oldest available
record on all consoles and call console_unlock() which will
automatically flush the messages to the consoles.
Suggested-by: John Ogness <john.ogness@linutronix.de>
Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Shimoyashiki Taichi <taichi.shimoyashiki@sony.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Sreenath Vijayan <sreenath.vijayan@sony.com>
Link: https://lore.kernel.org/r/90ee131c643a5033d117b556c0792de65129d4c3.1710220326.git.sreenath.vijayan@sony.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If add_preferred_console() is not called early in setup_console(), we can
end up having register_console() call try_enable_default_console() before a
console device has called add_preferred_console().
Let's set console_set_on_cmdline flag in console_setup() to prevent this
from happening.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20240327110021.59793-4-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently console_setup() tries to make a console index out of any digits
passed in the kernel command line for console. In the DEVNAME:0.0 case,
the name can contain a device IO address, so bail out on console names
with a ':'.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20240327110021.59793-3-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Driver subsystems may need to translate the preferred console name to the
character device name used. We already do some of this in console_setup()
with a few hardcoded names, but that does not scale well.
The console options are parsed early in console_setup(), and the consoles
are added with __add_preferred_console(). At this point we don't know much
about the character device names and device drivers getting probed.
To allow driver subsystems to set up a preferred console, let's save the
kernel command line console options. To add a preferred console from a
driver subsystem with optional character device name translation, let's
add a new function add_preferred_console_match().
This allows the serial core layer to support console=DEVNAME:0.0 style
hardware based addressing in addition to the current console=ttyS0 style
naming. And we can start moving console_setup() character device parsing
to the driver subsystem specific code.
We use a separate array from the console_cmdline array as the character
device name and index may be unknown at the console_setup() time. And
eventually there's no need to call __add_preferred_console() until the
subsystem is ready to handle the console.
Adding the console name in addition to the character device name, and a
flag for an added console, could be added to the struct console_cmdline.
And the console_cmdline array handling could be modified accordingly. But
that complicates things compared saving the console options, and then
adding the consoles when the subsystems handling the consoles are ready.
Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240327110021.59793-2-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----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=7UMV
-----END PGP SIGNATURE-----
Merge tag 'printk-for-6.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk fix from Petr Mladek:
- Prevent scheduling in an atomic context when printk() takes over the
console flushing duty
* tag 'printk-for-6.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk: Update @console_may_schedule in console_trylock_spinning()
Here is the big set of TTY/Serial driver updates and cleanups for
6.9-rc1. Included in here are:
- more tty cleanups from Jiri
- loads of 8250 driver cleanups from Andy
- max310x driver updates
- samsung serial driver updates
- uart_prepare_sysrq_char() updates for many drivers
- platform driver remove callback void cleanups
- stm32 driver updates
- other small tty/serial driver updates
All of these have been in linux-next for a long time with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCZfwqow8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ynNegCffxTbsnbMGjWhVrQ326IJx/DFvNMAoI9csigv
m+G3RzefzZLRx8nAma0c
=GMfc
-----END PGP SIGNATURE-----
Merge tag 'tty-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty / serial driver updates from Greg KH:
"Here is the big set of TTY/Serial driver updates and cleanups for
6.9-rc1. Included in here are:
- more tty cleanups from Jiri
- loads of 8250 driver cleanups from Andy
- max310x driver updates
- samsung serial driver updates
- uart_prepare_sysrq_char() updates for many drivers
- platform driver remove callback void cleanups
- stm32 driver updates
- other small tty/serial driver updates
All of these have been in linux-next for a long time with no reported
issues"
* tag 'tty-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits)
dt-bindings: serial: stm32: add power-domains property
serial: 8250_dw: Replace ACPI device check by a quirk
serial: Lock console when calling into driver before registration
serial: 8250_uniphier: Switch to use uart_read_port_properties()
serial: 8250_tegra: Switch to use uart_read_port_properties()
serial: 8250_pxa: Switch to use uart_read_port_properties()
serial: 8250_omap: Switch to use uart_read_port_properties()
serial: 8250_of: Switch to use uart_read_port_properties()
serial: 8250_lpc18xx: Switch to use uart_read_port_properties()
serial: 8250_ingenic: Switch to use uart_read_port_properties()
serial: 8250_dw: Switch to use uart_read_port_properties()
serial: 8250_bcm7271: Switch to use uart_read_port_properties()
serial: 8250_bcm2835aux: Switch to use uart_read_port_properties()
serial: 8250_aspeed_vuart: Switch to use uart_read_port_properties()
serial: port: Introduce a common helper to read properties
serial: core: Add UPIO_UNKNOWN constant for unknown port type
serial: core: Move struct uart_port::quirks closer to possible values
serial: sh-sci: Call sci_serial_{in,out}() directly
serial: core: only stop transmit when HW fifo is empty
serial: pch: Use uart_prepare_sysrq_char().
...
console_trylock_spinning() may takeover the console lock from a
schedulable context. Update @console_may_schedule to make sure it
reflects a trylock acquire.
Reported-by: Mukesh Ojha <quic_mojha@quicinc.com>
Closes: https://lore.kernel.org/lkml/20240222090538.23017-1-quic_mojha@quicinc.com
Fixes: dbdda842fe ("printk: Add console owner and waiter logic to load balance console writes")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/875xybmo2z.fsf@jogness.linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
from hotplugged memory rather than only from main memory. Series
"implement "memmap on memory" feature on s390".
- More folio conversions from Matthew Wilcox in the series
"Convert memcontrol charge moving to use folios"
"mm: convert mm counter to take a folio"
- Chengming Zhou has optimized zswap's rbtree locking, providing
significant reductions in system time and modest but measurable
reductions in overall runtimes. The series is "mm/zswap: optimize the
scalability of zswap rb-tree".
- Chengming Zhou has also provided the series "mm/zswap: optimize zswap
lru list" which provides measurable runtime benefits in some
swap-intensive situations.
- And Chengming Zhou further optimizes zswap in the series "mm/zswap:
optimize for dynamic zswap_pools". Measured improvements are modest.
- zswap cleanups and simplifications from Yosry Ahmed in the series "mm:
zswap: simplify zswap_swapoff()".
- In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
contributed several DAX cleanups as well as adding a sysfs tunable to
control the memmap_on_memory setting when the dax device is hotplugged
as system memory.
- Johannes Weiner has added the large series "mm: zswap: cleanups",
which does that.
- More DAMON work from SeongJae Park in the series
"mm/damon: make DAMON debugfs interface deprecation unignorable"
"selftests/damon: add more tests for core functionalities and corner cases"
"Docs/mm/damon: misc readability improvements"
"mm/damon: let DAMOS feeds and tame/auto-tune itself"
- In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
extension" Rakie Kim has developed a new mempolicy interleaving policy
wherein we allocate memory across nodes in a weighted fashion rather
than uniformly. This is beneficial in heterogeneous memory environments
appearing with CXL.
- Christophe Leroy has contributed some cleanup and consolidation work
against the ARM pagetable dumping code in the series "mm: ptdump:
Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".
- Luis Chamberlain has added some additional xarray selftesting in the
series "test_xarray: advanced API multi-index tests".
- Muhammad Usama Anjum has reworked the selftest code to make its
human-readable output conform to the TAP ("Test Anything Protocol")
format. Amongst other things, this opens up the use of third-party
tools to parse and process out selftesting results.
- Ryan Roberts has added fork()-time PTE batching of THP ptes in the
series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
targeted at arm64, this significantly speeds up fork() when the process
has a large number of pte-mapped folios.
- David Hildenbrand also gets in on the THP pte batching game in his
series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
implements batching during munmap() and other pte teardown situations.
The microbenchmark improvements are nice.
- And in the series "Transparent Contiguous PTEs for User Mappings" Ryan
Roberts further utilizes arm's pte's contiguous bit ("contpte
mappings"). Kernel build times on arm64 improved nicely. Ryan's series
"Address some contpte nits" provides some followup work.
- In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
fixed an obscure hugetlb race which was causing unnecessary page faults.
He has also added a reproducer under the selftest code.
- In the series "selftests/mm: Output cleanups for the compaction test",
Mark Brown did what the title claims.
- Kinsey Ho has added the series "mm/mglru: code cleanup and refactoring".
- Even more zswap material from Nhat Pham. The series "fix and extend
zswap kselftests" does as claimed.
- In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
regression" Mathieu Desnoyers has cleaned up and fixed rather a mess in
our handling of DAX on archiecctures which have virtually aliasing data
caches. The arm architecture is the main beneficiary.
- Lokesh Gidra's series "per-vma locks in userfaultfd" provides dramatic
improvements in worst-case mmap_lock hold times during certain
userfaultfd operations.
- Some page_owner enhancements and maintenance work from Oscar Salvador
in his series
"page_owner: print stacks and their outstanding allocations"
"page_owner: Fixup and cleanup"
- Uladzislau Rezki has contributed some vmalloc scalability improvements
in his series "Mitigate a vmap lock contention". It realizes a 12x
improvement for a certain microbenchmark.
- Some kexec/crash cleanup work from Baoquan He in the series "Split
crash out from kexec and clean up related config items".
- Some zsmalloc maintenance work from Chengming Zhou in the series
"mm/zsmalloc: fix and optimize objects/page migration"
"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"
- Zi Yan has taught the MM to perform compaction on folios larger than
order=0. This a step along the path to implementaton of the merging of
large anonymous folios. The series is named "Enable >0 order folio
memory compaction".
- Christoph Hellwig has done quite a lot of cleanup work in the
pagecache writeback code in his series "convert write_cache_pages() to
an iterator".
- Some modest hugetlb cleanups and speedups in Vishal Moola's series
"Handle hugetlb faults under the VMA lock".
- Zi Yan has changed the page splitting code so we can split huge pages
into sizes other than order-0 to better utilize large folios. The
series is named "Split a folio to any lower order folios".
- David Hildenbrand has contributed the series "mm: remove
total_mapcount()", a cleanup.
- Matthew Wilcox has sought to improve the performance of bulk memory
freeing in his series "Rearrange batched folio freeing".
- Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
provides large improvements in bootup times on large machines which are
configured to use large numbers of hugetlb pages.
- Matthew Wilcox's series "PageFlags cleanups" does that.
- Qi Zheng's series "minor fixes and supplement for ptdesc" does that
also. S390 is affected.
- Cleanups to our pagemap utility functions from Peter Xu in his series
"mm/treewide: Replace pXd_large() with pXd_leaf()".
- Nico Pache has fixed a few things with our hugepage selftests in his
series "selftests/mm: Improve Hugepage Test Handling in MM Selftests".
- Also, of course, many singleton patches to many things. Please see
the individual changelogs for details.
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZfJpPQAKCRDdBJ7gKXxA
joxeAP9TrcMEuHnLmBlhIXkWbIR4+ki+pA3v+gNTlJiBhnfVSgD9G55t1aBaRplx
TMNhHfyiHYDTx/GAV9NXW84tasJSDgA=
=TG55
-----END PGP SIGNATURE-----
Merge tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
from hotplugged memory rather than only from main memory. Series
"implement "memmap on memory" feature on s390".
- More folio conversions from Matthew Wilcox in the series
"Convert memcontrol charge moving to use folios"
"mm: convert mm counter to take a folio"
- Chengming Zhou has optimized zswap's rbtree locking, providing
significant reductions in system time and modest but measurable
reductions in overall runtimes. The series is "mm/zswap: optimize the
scalability of zswap rb-tree".
- Chengming Zhou has also provided the series "mm/zswap: optimize zswap
lru list" which provides measurable runtime benefits in some
swap-intensive situations.
- And Chengming Zhou further optimizes zswap in the series "mm/zswap:
optimize for dynamic zswap_pools". Measured improvements are modest.
- zswap cleanups and simplifications from Yosry Ahmed in the series
"mm: zswap: simplify zswap_swapoff()".
- In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
contributed several DAX cleanups as well as adding a sysfs tunable to
control the memmap_on_memory setting when the dax device is
hotplugged as system memory.
- Johannes Weiner has added the large series "mm: zswap: cleanups",
which does that.
- More DAMON work from SeongJae Park in the series
"mm/damon: make DAMON debugfs interface deprecation unignorable"
"selftests/damon: add more tests for core functionalities and corner cases"
"Docs/mm/damon: misc readability improvements"
"mm/damon: let DAMOS feeds and tame/auto-tune itself"
- In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
extension" Rakie Kim has developed a new mempolicy interleaving
policy wherein we allocate memory across nodes in a weighted fashion
rather than uniformly. This is beneficial in heterogeneous memory
environments appearing with CXL.
- Christophe Leroy has contributed some cleanup and consolidation work
against the ARM pagetable dumping code in the series "mm: ptdump:
Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".
- Luis Chamberlain has added some additional xarray selftesting in the
series "test_xarray: advanced API multi-index tests".
- Muhammad Usama Anjum has reworked the selftest code to make its
human-readable output conform to the TAP ("Test Anything Protocol")
format. Amongst other things, this opens up the use of third-party
tools to parse and process out selftesting results.
- Ryan Roberts has added fork()-time PTE batching of THP ptes in the
series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
targeted at arm64, this significantly speeds up fork() when the
process has a large number of pte-mapped folios.
- David Hildenbrand also gets in on the THP pte batching game in his
series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
implements batching during munmap() and other pte teardown
situations. The microbenchmark improvements are nice.
- And in the series "Transparent Contiguous PTEs for User Mappings"
Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
mappings"). Kernel build times on arm64 improved nicely. Ryan's
series "Address some contpte nits" provides some followup work.
- In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
fixed an obscure hugetlb race which was causing unnecessary page
faults. He has also added a reproducer under the selftest code.
- In the series "selftests/mm: Output cleanups for the compaction
test", Mark Brown did what the title claims.
- Kinsey Ho has added the series "mm/mglru: code cleanup and
refactoring".
- Even more zswap material from Nhat Pham. The series "fix and extend
zswap kselftests" does as claimed.
- In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
in our handling of DAX on archiecctures which have virtually aliasing
data caches. The arm architecture is the main beneficiary.
- Lokesh Gidra's series "per-vma locks in userfaultfd" provides
dramatic improvements in worst-case mmap_lock hold times during
certain userfaultfd operations.
- Some page_owner enhancements and maintenance work from Oscar Salvador
in his series
"page_owner: print stacks and their outstanding allocations"
"page_owner: Fixup and cleanup"
- Uladzislau Rezki has contributed some vmalloc scalability
improvements in his series "Mitigate a vmap lock contention". It
realizes a 12x improvement for a certain microbenchmark.
- Some kexec/crash cleanup work from Baoquan He in the series "Split
crash out from kexec and clean up related config items".
- Some zsmalloc maintenance work from Chengming Zhou in the series
"mm/zsmalloc: fix and optimize objects/page migration"
"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"
- Zi Yan has taught the MM to perform compaction on folios larger than
order=0. This a step along the path to implementaton of the merging
of large anonymous folios. The series is named "Enable >0 order folio
memory compaction".
- Christoph Hellwig has done quite a lot of cleanup work in the
pagecache writeback code in his series "convert write_cache_pages()
to an iterator".
- Some modest hugetlb cleanups and speedups in Vishal Moola's series
"Handle hugetlb faults under the VMA lock".
- Zi Yan has changed the page splitting code so we can split huge pages
into sizes other than order-0 to better utilize large folios. The
series is named "Split a folio to any lower order folios".
- David Hildenbrand has contributed the series "mm: remove
total_mapcount()", a cleanup.
- Matthew Wilcox has sought to improve the performance of bulk memory
freeing in his series "Rearrange batched folio freeing".
- Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
provides large improvements in bootup times on large machines which
are configured to use large numbers of hugetlb pages.
- Matthew Wilcox's series "PageFlags cleanups" does that.
- Qi Zheng's series "minor fixes and supplement for ptdesc" does that
also. S390 is affected.
- Cleanups to our pagemap utility functions from Peter Xu in his series
"mm/treewide: Replace pXd_large() with pXd_leaf()".
- Nico Pache has fixed a few things with our hugepage selftests in his
series "selftests/mm: Improve Hugepage Test Handling in MM
Selftests".
- Also, of course, many singleton patches to many things. Please see
the individual changelogs for details.
* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
mm/zswap: remove the memcpy if acomp is not sleepable
crypto: introduce: acomp_is_async to expose if comp drivers might sleep
memtest: use {READ,WRITE}_ONCE in memory scanning
mm: prohibit the last subpage from reusing the entire large folio
mm: recover pud_leaf() definitions in nopmd case
selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
selftests/mm: skip uffd hugetlb tests with insufficient hugepages
selftests/mm: dont fail testsuite due to a lack of hugepages
mm/huge_memory: skip invalid debugfs new_order input for folio split
mm/huge_memory: check new folio order when split a folio
mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
mm: fix list corruption in put_pages_list
mm: remove folio from deferred split list before uncharging it
filemap: avoid unnecessary major faults in filemap_fault()
mm,page_owner: drop unnecessary check
mm,page_owner: check for null stack_record before bumping its refcount
mm: swap: fix race between free_swap_and_cache() and swapoff()
mm/treewide: align up pXd_leaf() retval across archs
mm/treewide: drop pXd_large()
...
-----BEGIN PGP SIGNATURE-----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=Z413
-----END PGP SIGNATURE-----
Merge tag 'printk-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek:
"Improve the behavior during panic. The issues were found when testing
the ongoing changes introducing atomic consoles and printk kthreads:
- pr_flush() has to wait for the last reserved record instead of the
last finalized one. Note that records are finalized in random order
when generated by more CPUs in parallel.
- Ignore non-finalized records during panic(). Messages printed on
panic-CPU are always finalized. Messages printed by other CPUs
might never be finalized when the CPUs get stopped.
- Block new printk() calls on non-panic CPUs completely. Backtraces
are printed before entering the panic mode. Later messages would
just mess information printed by the panic CPU.
- Do not take console_lock in console_flush_on_panic() at all. The
original code did try_lock()/console_unlock(). The unlock part
might cause a deadlock when panic() happened in a scheduler code.
- Fix conversion of 64-bit sequence number for 32-bit atomic
operations"
* tag 'printk-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
dump_stack: Do not get cpu_sync for panic CPU
panic: Flush kernel log buffer at the end
printk: Avoid non-panic CPUs writing to ringbuffer
printk: Disable passing console lock owner completely during panic()
printk: ringbuffer: Skip non-finalized records in panic
printk: Wait for all reserved records with pr_flush()
printk: ringbuffer: Cleanup reader terminology
printk: Add this_cpu_in_panic()
printk: For @suppress_panic_printk check for other CPU in panic
printk: ringbuffer: Clarify special lpos values
printk: ringbuffer: Do not skip non-finalized records with prb_next_seq()
printk: Use prb_first_seq() as base for 32bit seq macros
printk: Adjust mapping for 32bit seq macros
printk: nbcon: Relocate 32bit seq macros
During the handoff from earlycon to the real console driver, we have
two separate drivers operating on the same device concurrently. In the
case of the 8250 driver these concurrent accesses cause problems due
to the driver's use of banked registers, controlled by LCR.DLAB. It is
possible for the setup(), config_port(), pm() and set_mctrl() callbacks
to set DLAB, which can cause the earlycon code that intends to access
TX to instead access DLL, leading to missed output and corruption on
the serial line due to unintended modifications to the baud rate.
In particular, for setup() we have:
univ8250_console_setup()
-> serial8250_console_setup()
-> uart_set_options()
-> serial8250_set_termios()
-> serial8250_do_set_termios()
-> serial8250_do_set_divisor()
For config_port() we have:
serial8250_config_port()
-> autoconfig()
For pm() we have:
serial8250_pm()
-> serial8250_do_pm()
-> serial8250_set_sleep()
For set_mctrl() we have (for some devices):
serial8250_set_mctrl()
-> omap8250_set_mctrl()
-> __omap8250_set_mctrl()
To avoid such problems, let's make it so that the console is locked
during pre-registration calls to these callbacks, which will prevent
the earlycon driver from running concurrently.
Remove the partial solution to this problem in the 8250 driver
that locked the console only during autoconfig_irq(), as this would
result in a deadlock with the new approach. The console continues
to be locked during autoconfig_irq() because it can only be called
through uart_configure_port().
Although this patch introduces more locking than strictly necessary
(and in particular it also locks during the call to rs485_config()
which is not affected by this issue as far as I can tell), it follows
the principle that it is the responsibility of the generic console
code to manage the earlycon handoff by ensuring that earlycon and real
console driver code cannot run concurrently, and not the individual
drivers.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://linux-review.googlesource.com/id/I7cf8124dcebf8618e6b2ee543fa5b25532de55d8
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240304214350.501253-1-pcc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now move the relevant codes into separate files:
kernel/crash_reserve.c, include/linux/crash_reserve.h.
And add config item CRASH_RESERVE to control its enabling.
And also update the old ifdeffery of CONFIG_CRASH_CORE, including of
<linux/crash_core.h> and config item dependency on CRASH_CORE
accordingly.
And also do renaming as follows:
- arch/xxx/kernel/{crash_core.c => vmcore_info.c}
because they are only related to vmcoreinfo exporting on x86, arm64,
riscv.
And also Remove config item CRASH_CORE, and rely on CONFIG_KEXEC_CORE to
decide if build in crash_core.c.
[yang.lee@linux.alibaba.com: remove duplicated include in vmcore_info.c]
Link: https://lkml.kernel.org/r/20240126005744.16561-1-yang.lee@linux.alibaba.com
Link: https://lkml.kernel.org/r/20240124051254.67105-3-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Pingfan Liu <piliu@redhat.com>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Michael Kelley <mhklinux@outlook.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 13fb0f74d7 ("printk: Avoid livelock with heavy printk
during panic") introduced a mechanism to silence non-panic CPUs
if too many messages are being dropped. Aside from trying to
workaround the livelock bugs of legacy consoles, it was also
intended to avoid losing panic messages. However, if non-panic
CPUs are writing to the ringbuffer, then reacting to dropped
messages is too late.
Another motivation is that non-finalized messages already might
be skipped in panic(). In other words, random messages from
non-panic CPUs might already get lost. It is better to ignore
all to avoid confusion.
To avoid losing panic CPU messages, silence non-panic CPUs
immediately on panic.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240207134103.1357162-13-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
The commit d51507098f ("printk: disable optimistic spin
during panic") added checks to avoid becoming a console waiter
if a panic is in progress.
However, the transition to panic can occur while there is
already a waiter. The current owner should not pass the lock to
the waiter because it might get stopped or blocked anytime.
Also the panic context might pass the console lock owner to an
already stopped waiter by mistake. It might happen when
console_flush_on_panic() ignores the current lock owner, for
example:
CPU0 CPU1
---- ----
console_lock_spinning_enable()
console_trylock_spinning()
[CPU1 now console waiter]
NMI: panic()
panic_other_cpus_shutdown()
[stopped as console waiter]
console_flush_on_panic()
console_lock_spinning_enable()
[print 1 record]
console_lock_spinning_disable_and_check()
[handover to stopped CPU1]
This results in panic() not flushing the panic messages.
Fix these problems by disabling all spinning operations
completely during panic().
Another advantage is that it prevents possible deadlocks caused
by "console_owner_lock". The panic() context does not need to
take it any longer. The lockless checks are safe because the
functions become NOPs when they see the panic in progress. All
operations manipulating the state are still synchronized by the
lock even when non-panic CPUs would notice the panic
synchronously.
The current owner might stay spinning. But non-panic() CPUs
would get stopped anyway and the panic context will never start
spinning.
Fixes: dbdda842fe ("printk: Add console owner and waiter logic to load balance console writes")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20240207134103.1357162-12-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
Currently pr_flush() will only wait for records that were
available to readers at the time of the call (using
prb_next_seq()). But there may be more records (non-finalized)
that have following finalized records. pr_flush() should wait
for these to print as well. Particularly because any trailing
finalized records may be the messages that the calling context
wants to ensure are printed.
Add a new ringbuffer function prb_next_reserve_seq() to return
the sequence number following the most recently reserved record.
This guarantees that pr_flush() will wait until all current
printk() messages (completed or in progress) have been printed.
Fixes: 3b604ca812 ("printk: add pr_flush()")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240207134103.1357162-10-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
There is already panic_in_progress() and other_cpu_in_panic(),
but checking if the current CPU is the panic CPU must still be
open coded.
Add this_cpu_in_panic() to complete the set.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240207134103.1357162-8-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
Currently @suppress_panic_printk is checked along with
non-matching @panic_cpu and current CPU. This works
because @suppress_panic_printk is only set when
panic_in_progress() is true.
Rather than relying on the @suppress_panic_printk semantics,
use the concise helper function other_cpu_in_progress(). The
helper function exists to avoid open coding such tests.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240207134103.1357162-7-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
CAP_SYSLOG was separated from CAP_SYS_ADMIN and introduced in Linux
2.6.37 (2010-11). For a long time, certain syslog actions required
CAP_SYS_ADMIN or CAP_SYSLOG. Maybe it’s time to officially remove
CAP_SYS_ADMIN for more fine-grained control.
CAP_SYS_ADMIN was once removed but added back for backwards
compatibility reasons. In commit 38ef4c2e43 ("syslog: check cap_syslog
when dmesg_restrict") (2010-12), CAP_SYS_ADMIN was no longer needed. And
in commit ee24aebffb ("cap_syslog: accept CAP_SYS_ADMIN for now")
(2011-02), it was accepted again. Since then, CAP_SYS_ADMIN has been
preserved.
Now that almost 13 years have passed, the legacy application may have
had enough time to be updated.
Signed-off-by: Jingzi Meng <mengjingzi@iie.ac.cn>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240105062007.26965-1-mengjingzi@iie.ac.cn
Signed-off-by: Kees Cook <keescook@chromium.org>
Here is the big set of tty/serial driver changes for 6.7-rc1. Included
in here are:
- console/vgacon cleanups and removals from Arnd
- tty core and n_tty cleanups from Jiri
- lots of 8250 driver updates and cleanups
- sc16is7xx serial driver updates
- dt binding updates
- first set of port lock wrapers from Thomas for the printk fixes
coming in future releases
- other small serial and tty core cleanups and updates
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCZUTbaw8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+yk9+gCeKdoRb8FDwGCO/GaoHwR4EzwQXhQAoKXZRmN5
LTtw9sbfGIiBdOTtgLPb
=6PJr
-----END PGP SIGNATURE-----
Merge tag 'tty-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty and serial updates from Greg KH:
"Here is the big set of tty/serial driver changes for 6.7-rc1. Included
in here are:
- console/vgacon cleanups and removals from Arnd
- tty core and n_tty cleanups from Jiri
- lots of 8250 driver updates and cleanups
- sc16is7xx serial driver updates
- dt binding updates
- first set of port lock wrapers from Thomas for the printk fixes
coming in future releases
- other small serial and tty core cleanups and updates
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (193 commits)
serdev: Replace custom code with device_match_acpi_handle()
serdev: Simplify devm_serdev_device_open() function
serdev: Make use of device_set_node()
tty: n_gsm: add copyright Siemens Mobility GmbH
tty: n_gsm: fix race condition in status line change on dead connections
serial: core: Fix runtime PM handling for pending tx
vgacon: fix mips/sibyte build regression
dt-bindings: serial: drop unsupported samsung bindings
tty: serial: samsung: drop earlycon support for unsupported platforms
tty: 8250: Add note for PX-835
tty: 8250: Fix IS-200 PCI ID comment
tty: 8250: Add Brainboxes Oxford Semiconductor-based quirks
tty: 8250: Add support for Intashield IX cards
tty: 8250: Add support for additional Brainboxes PX cards
tty: 8250: Fix up PX-803/PX-857
tty: 8250: Fix port count of PX-257
tty: 8250: Add support for Intashield IS-100
tty: 8250: Add support for Brainboxes UP cards
tty: 8250: Add support for additional Brainboxes UC cards
tty: 8250: Remove UC-257 and UC-431
...
In the following two functions, len has already been assigned a value of
0 when defining the variable, so remove 'len=0;'.
Signed-off-by: Li kunyu <kunyu@nfschina.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20231023062359.130633-1-kunyu@nfschina.com
While adding a preferred console handling for serial_core for serial port
hardware based device addressing, Jiri suggested we constify name for
add_preferred_console(). The name gets copied anyways. This allows serial
core to add a preferred console using serial drv->dev_name without copying
it.
Note that constifying options causes changes all over the place because of
struct console for match().
Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20231012064300.50221-2-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Let's check for valid console index values for preferred console to avoid
bogus console index numbers from kernel command line.
Let's also return an error for negative index numbers for the preferred
console. Unlike for device drivers, a negative index is not valid for the
preferred console.
Let's also constify idx while at it.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20231012064300.50221-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pr_flush() does not guarantee that all messages would really get flushed
to the console. The best it could do is to wait with a given timeout.[*]
The current interval 100ms for checking the progress might seem too
long in some situations. For example, such delays are not appreciated
during suspend and resume especially when the consoles have been flushed
"long" time before the check.
On the other hand, the sleeping wait might be useful in other situations.
Especially, it would allow flushing the messages using printk kthreads
on the same CPU[*].
Use msleep(1) as a compromise.
Also measure the time using jiffies. msleep() does not guarantee
precise wakeup after the given delay. It might be much longer,
especially for times < 20s. See Documentation/timers/timers-howto.rst
for more details.
Note that msecs_to_jiffies() already translates a negative value into
an infinite timeout.
[*] console_unlock() does not guarantee flushing the consoles since
the commit dbdda842fe ("printk: Add console owner and waiter
logic to load balance console writes").
It would be possible to guarantee it another way. For example,
the spinning might be enabled only when the console_lock has been
taken via console_trylock().
But the load balancing is helpful. And more importantly, the flush
with a timeout has been added as a preparation step for introducing
printk kthreads.
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20231006082151.6969-3-pmladek@suse.com
Commit 9e70a5e109 ("printk: Add per-console suspended state")
removed console lock usage during resume and replaced it with
the clearly defined console_list_lock and srcu mechanisms.
However, the console lock usage had an important side-effect
of flushing the consoles. After its removal, consoles were no
longer flushed before checking their progress.
Add the console_lock/console_unlock dance to the beginning
of __pr_flush() to actually flush the consoles before checking
their progress. Also add comments to clarify this additional
usage of the console lock.
Note that console_unlock() does not guarantee flushing all messages
since the commit dbdda842fe ("printk: Add console owner and waiter
logic to load balance console writes").
Reported-by: Todd Brandt <todd.e.brandt@intel.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217955
Fixes: 9e70a5e109 ("printk: Add per-console suspended state")
Co-developed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20231006082151.6969-2-pmladek@suse.com
When CONFIG_PRINTK is not set, PRINTK_MESSAGE_MAX is 0. This
leads to a zero-sized array @outbuf in @printk_shared_pbufs. In
console_flush_all() a pointer to the first element of the array
is assigned with:
char *outbuf = &printk_shared_pbufs.outbuf[0];
For !CONFIG_PRINTK this leads to a compiler warning:
warning: array subscript 0 is outside array bounds of
'char[0]' [-Warray-bounds]
This is not really dangerous because printk_get_next_message()
always returns false for !CONFIG_PRINTK, which leads to @outbuf
never being used. However, it makes no sense to even compile
these functions for !CONFIG_PRINTK.
Extend the existing '#ifdef CONFIG_PRINTK' block to contain
the formatting and emitting functions since these have no
purpose in !CONFIG_PRINTK. This also allows removing several
more !CONFIG_PRINTK dummies as well as moving
@suppress_panic_printk into a CONFIG_PRINTK block.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202309201724.M9BMAQIh-lkp@intel.com/
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230920155238.670439-1-john.ogness@linutronix.de
Implement an emit function for nbcon consoles to output printk
messages. It utilizes the lockless printk_get_next_message() and
console_prepend_dropped() functions to retrieve/build the output
message. The emit function includes the required safety points to
check for handover/takeover and calls a new write_atomic callback
of the console driver to output the message. It also includes
proper handling for updating the nbcon console sequence number.
A new nbcon_write_context struct is introduced. This is provided
to the write_atomic callback and includes only the information
necessary for performing atomic writes.
Co-developed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230916192007.608398-8-john.ogness@linutronix.de
Add an atomic_long_t field @nbcon_seq to the console struct to
store the sequence number for nbcon consoles. For nbcon consoles
this will be used instead of the non-atomic @seq field. The new
field allows for safe atomic sequence number updates without
requiring any locking.
On 64bit systems the new field stores the full sequence number.
On 32bit systems the new field stores the lower 32 bits of the
sequence number, which are expanded to 64bit as needed by
folding the values based on the sequence numbers available in
the ringbuffer.
For 32bit systems, having a 32bit representation in the console
is sufficient. If a console ever gets more than 2^31 records
behind the ringbuffer then this is the least of the problems.
Co-developed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230916192007.608398-7-john.ogness@linutronix.de
In case of hostile takeovers it must be ensured that the previous
owner cannot scribble over the output buffer of the emergency/panic
context. This is achieved by:
- Adding a global output buffer instance for the panic context.
This is the only situation where hostile takeovers can occur and
there is always at most 1 panic context.
- Allocating an output buffer per non-boot console upon console
registration. This buffer is used by the console owner when not
in panic context. (For boot consoles, the existing shared global
legacy output buffer is used instead. Boot console printing will
be synchronized with legacy console printing.)
- Choosing the appropriate buffer is handled in the acquire/release
functions.
Co-developed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230916192007.608398-5-john.ogness@linutronix.de
The nbcon boot consoles also need printk buffers that are available
very early. Since the nbcon boot consoles will also be serialized
by the console_lock, they can use the same static printk buffers
that the legacy consoles are using.
Make the legacy static printk buffers available outside of printk.c
so they can be used by nbcon.c.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230916192007.608398-4-john.ogness@linutronix.de
The current console/printk subsystem is protected by a Big Kernel Lock,
(aka console_lock) which has ill defined semantics and is more or less
stateless. This puts severe limitations on the console subsystem and
makes forced takeover and output in emergency and panic situations a
fragile endeavour that is based on try and pray.
The goal of non-BKL (nbcon) consoles is to break out of the console lock
jail and to provide a new infrastructure that avoids the pitfalls and
also allows console drivers to be gradually converted over.
The proposed infrastructure aims for the following properties:
- Per console locking instead of global locking
- Per console state that allows to make informed decisions
- Stateful handover and takeover
As a first step, state is added to struct console. The per console state
is an atomic_t using a 32bit bit field.
Reserve state bits, which will be populated later in the series. Wire
it up into the console register/unregister functionality.
It was decided to use a bitfield because using a plain u32 with
mask/shift operations resulted in uncomprehensible code.
Co-developed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230916192007.608398-2-john.ogness@linutronix.de
This reverts commit 3e00123a13.
No, we never export random symbols for out of tree modules.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230905081902.321778-1-hch@lst.de
-----BEGIN PGP SIGNATURE-----
iQIzBAABCAAdFiEESH4wyp42V4tXvYsjUqAMR0iAlPIFAmT1pbAACgkQUqAMR0iA
lPLoxBAAl18gKo6C8zIBNBoYNl7FxvChrJORjK7RQONs5RYKt8drHjSrJGazhjiV
TIdbZt9juqs+UT/f6DnkJznrqQ0W70fQsgUpw+q7n7+cnkIoXAiAs+plexdQXigB
6nx67b2oub41jTwzn/uV7R/eTwq2VnoZqudS/o9iAI/Ia9JzkqmGx08hQedvOoqX
2SWs140iY/zXsFUyEfe8UTXwJUnC/n9pwtpe5sLpmtyupGc/KumUimTQ+LFJbV9o
n8QhcQn10CE93M5fH/R2JXjZO7wuSmCHt/V8oSnoOwdCBBe7Tc6aBx5wUwc4XCuC
450h5hlYBKq97lA1PnWGC01uAkeDTRw8963LVRRqWvohoFuHXR0cisF9FTM9LXfs
bg90XjzYAK7Ns9fJ0dZHOSbUtRaa06hiExUnO3ctyv2G6h8qKfv86LCuP0CMFmQU
rflfk1dPiMW20HT3ZJNtMCy3Vu6kVQSdSaGKTnwzTcUWop5tCQxhmWYBXH6q/1LH
aD7xT1xJnBGqLUqq5C8twoOea+w47x/vtjTLi7mJarP5Wfh8xv6axdkwE8N4NrYp
cc2RR83a1BZ7At3YkAjfjHmhaZ97gSSe6+Yqk9UzvUEQY/WILEGnb0DKO1jCSB34
D2NPh1MHF5MFQjazdt/dSyMJVxDlTeY/S5wqfLLhNZts48LJ8n0=
=D7ZU
-----END PGP SIGNATURE-----
Merge tag 'printk-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek:
- Do not try to get the console lock when it is not need or useful in
panic()
- Replace the global console_suspended state by a per-console flag
- Export symbols needed for dumping the raw printk buffer in panic()
- Fix documentation of printf formats for integer types
- Moved Sergey Senozhatsky to the reviewer role
- Misc cleanups
* tag 'printk-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk: export symbols for debug modules
lib: test_scanf: Add explicit type cast to result initialization in test_number_prefix()
printk: ringbuffer: Fix truncating buffer size min_t cast
printk: Rename abandon_console_lock_in_panic() to other_cpu_in_panic()
printk: Add per-console suspended state
printk: Consolidate console deferred printing
printk: Do not take console lock for console_flush_on_panic()
printk: Keep non-panic-CPUs out of console lock
printk: Reduce console_unblank() usage in unsafe scenarios
kdb: Do not assume write() callback available
docs: printk-formats: Treat char as always unsigned
docs: printk-formats: Fix hex printing of signed values
MAINTAINERS: adjust printk/vsprintf entries
the module is out-of-tree, it saves kernel logs when panic
Signed-off-by: Enlin Mu <enlin.mu@unisoc.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230815020711.2604939-1-yunlong.xing@unisoc.com
Currently abandon_console_lock_in_panic() is only used to determine if
the current CPU should immediately release the console lock because
another CPU is in panic. However, later this function will be used by
the CPU to immediately release other resources in this situation.
Rename the function to other_cpu_in_panic(), which is a better
description and does not assume it is related to the console lock.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230717194607.145135-8-john.ogness@linutronix.de
Currently the global @console_suspended is used to determine if
consoles are in a suspended state. Its primary purpose is to allow
usage of the console_lock when suspended without causing console
printing. It is synchronized by the console_lock.
Rather than relying on the console_lock to determine suspended
state, make it an official per-console state that is set within
console->flags. This allows the state to be queried via SRCU.
Remove @console_suspended. Console printing will still be avoided
when suspended because console_is_usable() returns false when
the new suspended flag is set for that console.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230717194607.145135-7-john.ogness@linutronix.de
Printing to consoles can be deferred for several reasons:
- explicitly with printk_deferred()
- printk() in NMI context
- recursive printk() calls
The current implementation is not consistent. For printk_deferred(),
irq work is scheduled twice. For NMI und recursive, panic CPU
suppression and caller delays are not properly enforced.
Correct these inconsistencies by consolidating the deferred printing
code so that vprintk_deferred() is the top-level function for
deferred printing and vprintk_emit() will perform whichever irq_work
queueing is appropriate.
Also add kerneldoc for wake_up_klogd() and defer_console_output() to
clarify their differences and appropriate usage.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230717194607.145135-6-john.ogness@linutronix.de
Currently console_flush_on_panic() will attempt to acquire the
console lock when flushing the buffer on panic. If it fails to
acquire the lock, it continues anyway because this is the last
chance to get any pending records printed.
The reason why the console lock was attempted at all was to
prevent any other CPUs from acquiring the console lock for
printing while the panic CPU was printing. But as of the
previous commit, non-panic CPUs will no longer attempt to
acquire the console lock in a panic situation. Therefore it is
no longer strictly necessary for a panic CPU to acquire the
console lock.
Avoiding taking the console lock when flushing in panic has
the additional benefit of avoiding possible deadlocks due to
semaphore usage in NMI context (semaphores are not NMI-safe)
and avoiding possible deadlocks if another CPU accesses the
semaphore and is stopped while holding one of the semaphore's
internal spinlocks.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230717194607.145135-5-john.ogness@linutronix.de
When in a panic situation, non-panic CPUs should avoid holding the
console lock so as not to contend with the panic CPU. This is already
implemented with abandon_console_lock_in_panic(), which is checked
after each printed line. However, non-panic CPUs should also avoid
trying to acquire the console lock during a panic.
Modify console_trylock() to fail and console_lock() to block() when
called from a non-panic CPU during a panic.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230717194607.145135-4-john.ogness@linutronix.de
A semaphore is not NMI-safe, even when using down_trylock(). Both
down_trylock() and up() are using internal spinlocks and up()
might even call wake_up_process().
In the panic() code path it gets even worse because the internal
spinlocks of the semaphore may have been taken by a CPU that has
been stopped.
To reduce the risk of deadlocks caused by the console semaphore in
the panic path, make the following changes:
- First check if any consoles have implemented the unblank()
callback. If not, then there is no reason to take the console
semaphore anyway. (This check is also useful for the non-panic
path since the locking/unlocking of the console lock can be
quite expensive due to console printing.)
- If the panic path is in NMI context, bail out without attempting
to take the console semaphore or calling any unblank() callbacks.
Bailing out is acceptable because console_unblank() would already
bail out if the console semaphore is contended. The alternative of
ignoring the console semaphore and calling the unblank() callbacks
anyway is a bad idea because these callbacks are also not NMI-safe.
If consoles with unblank() callbacks exist and console_unblank() is
called from a non-NMI panic context, it will still attempt a
down_trylock(). This could still result in a deadlock if one of the
stopped CPUs is holding the semaphore internal spinlock. But this
is a risk that the kernel has been (and continues to be) willing
to take.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230717194607.145135-3-john.ogness@linutronix.de
The read side of seqcount_latch consists of:
do {
seq = raw_read_seqcount_latch(&latch->seq);
...
} while (read_seqcount_latch_retry(&latch->seq, seq));
which is asymmetric in the raw_ department, and sure enough,
read_seqcount_latch_retry() includes (explicit) instrumentation where
raw_read_seqcount_latch() does not.
This inconsistency becomes a problem when trying to use it from
noinstr code. As such, fix it by renaming and re-implementing
raw_read_seqcount_latch_retry() without the instrumentation.
Specifically the instrumentation in question is kcsan_atomic_next(0)
in do___read_seqcount_retry(). Loosing this annotation is not a
problem because raw_read_seqcount_latch() does not pass through
kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V
Link: https://lore.kernel.org/r/20230519102715.233598176@infradead.org
switching from a user process to a kernel thread.
- More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav.
- zsmalloc performance improvements from Sergey Senozhatsky.
- Yue Zhao has found and fixed some data race issues around the
alteration of memcg userspace tunables.
- VFS rationalizations from Christoph Hellwig:
- removal of most of the callers of write_one_page().
- make __filemap_get_folio()'s return value more useful
- Luis Chamberlain has changed tmpfs so it no longer requires swap
backing. Use `mount -o noswap'.
- Qi Zheng has made the slab shrinkers operate locklessly, providing
some scalability benefits.
- Keith Busch has improved dmapool's performance, making part of its
operations O(1) rather than O(n).
- Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
permitting userspace to wr-protect anon memory unpopulated ptes.
- Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather
than exclusive, and has fixed a bunch of errors which were caused by its
unintuitive meaning.
- Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
which causes minor faults to install a write-protected pte.
- Vlastimil Babka has done some maintenance work on vma_merge():
cleanups to the kernel code and improvements to our userspace test
harness.
- Cleanups to do_fault_around() by Lorenzo Stoakes.
- Mike Rapoport has moved a lot of initialization code out of various
mm/ files and into mm/mm_init.c.
- Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
DRM, but DRM doesn't use it any more.
- Lorenzo has also coverted read_kcore() and vread() to use iterators
and has thereby removed the use of bounce buffers in some cases.
- Lorenzo has also contributed further cleanups of vma_merge().
- Chaitanya Prakash provides some fixes to the mmap selftesting code.
- Matthew Wilcox changes xfs and afs so they no longer take sleeping
locks in ->map_page(), a step towards RCUification of pagefaults.
- Suren Baghdasaryan has improved mmap_lock scalability by switching to
per-VMA locking.
- Frederic Weisbecker has reworked the percpu cache draining so that it
no longer causes latency glitches on cpu isolated workloads.
- Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
logic.
- Liu Shixin has changed zswap's initialization so we no longer waste a
chunk of memory if zswap is not being used.
- Yosry Ahmed has improved the performance of memcg statistics flushing.
- David Stevens has fixed several issues involving khugepaged,
userfaultfd and shmem.
- Christoph Hellwig has provided some cleanup work to zram's IO-related
code paths.
- David Hildenbrand has fixed up some issues in the selftest code's
testing of our pte state changing.
- Pankaj Raghav has made page_endio() unneeded and has removed it.
- Peter Xu contributed some rationalizations of the userfaultfd
selftests.
- Yosry Ahmed has fixed an issue around memcg's page recalim accounting.
- Chaitanya Prakash has fixed some arm-related issues in the
selftests/mm code.
- Longlong Xia has improved the way in which KSM handles hwpoisoned
pages.
- Peter Xu fixes a few issues with uffd-wp at fork() time.
- Stefan Roesch has changed KSM so that it may now be used on a
per-process and per-cgroup basis.
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZEr3zQAKCRDdBJ7gKXxA
jlLoAP0fpQBipwFxED0Us4SKQfupV6z4caXNJGPeay7Aj11/kQD/aMRC2uPfgr96
eMG3kwn2pqkB9ST2QpkaRbxA//eMbQY=
=J+Dj
-----END PGP SIGNATURE-----
Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
switching from a user process to a kernel thread.
- More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
Raghav.
- zsmalloc performance improvements from Sergey Senozhatsky.
- Yue Zhao has found and fixed some data race issues around the
alteration of memcg userspace tunables.
- VFS rationalizations from Christoph Hellwig:
- removal of most of the callers of write_one_page()
- make __filemap_get_folio()'s return value more useful
- Luis Chamberlain has changed tmpfs so it no longer requires swap
backing. Use `mount -o noswap'.
- Qi Zheng has made the slab shrinkers operate locklessly, providing
some scalability benefits.
- Keith Busch has improved dmapool's performance, making part of its
operations O(1) rather than O(n).
- Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
permitting userspace to wr-protect anon memory unpopulated ptes.
- Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
rather than exclusive, and has fixed a bunch of errors which were
caused by its unintuitive meaning.
- Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
which causes minor faults to install a write-protected pte.
- Vlastimil Babka has done some maintenance work on vma_merge():
cleanups to the kernel code and improvements to our userspace test
harness.
- Cleanups to do_fault_around() by Lorenzo Stoakes.
- Mike Rapoport has moved a lot of initialization code out of various
mm/ files and into mm/mm_init.c.
- Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
DRM, but DRM doesn't use it any more.
- Lorenzo has also coverted read_kcore() and vread() to use iterators
and has thereby removed the use of bounce buffers in some cases.
- Lorenzo has also contributed further cleanups of vma_merge().
- Chaitanya Prakash provides some fixes to the mmap selftesting code.
- Matthew Wilcox changes xfs and afs so they no longer take sleeping
locks in ->map_page(), a step towards RCUification of pagefaults.
- Suren Baghdasaryan has improved mmap_lock scalability by switching to
per-VMA locking.
- Frederic Weisbecker has reworked the percpu cache draining so that it
no longer causes latency glitches on cpu isolated workloads.
- Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
logic.
- Liu Shixin has changed zswap's initialization so we no longer waste a
chunk of memory if zswap is not being used.
- Yosry Ahmed has improved the performance of memcg statistics
flushing.
- David Stevens has fixed several issues involving khugepaged,
userfaultfd and shmem.
- Christoph Hellwig has provided some cleanup work to zram's IO-related
code paths.
- David Hildenbrand has fixed up some issues in the selftest code's
testing of our pte state changing.
- Pankaj Raghav has made page_endio() unneeded and has removed it.
- Peter Xu contributed some rationalizations of the userfaultfd
selftests.
- Yosry Ahmed has fixed an issue around memcg's page recalim
accounting.
- Chaitanya Prakash has fixed some arm-related issues in the
selftests/mm code.
- Longlong Xia has improved the way in which KSM handles hwpoisoned
pages.
- Peter Xu fixes a few issues with uffd-wp at fork() time.
- Stefan Roesch has changed KSM so that it may now be used on a
per-process and per-cgroup basis.
* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
shmem: restrict noswap option to initial user namespace
mm/khugepaged: fix conflicting mods to collapse_file()
sparse: remove unnecessary 0 values from rc
mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
maple_tree: fix allocation in mas_sparse_area()
mm: do not increment pgfault stats when page fault handler retries
zsmalloc: allow only one active pool compaction context
selftests/mm: add new selftests for KSM
mm: add new KSM process and sysfs knobs
mm: add new api to enable ksm per process
mm: shrinkers: fix debugfs file permissions
mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
migrate_pages_batch: fix statistics for longterm pin retry
userfaultfd: use helper function range_in_vma()
lib/show_mem.c: use for_each_populated_zone() simplify code
mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
fs/buffer: convert create_page_buffers to folio_create_buffers
fs/buffer: add folio_create_empty_buffers helper
...
The summary of the changes for this pull requests is:
* Song Liu's new struct module_memory replacement
* Nick Alcock's MODULE_LICENSE() removal for non-modules
* My cleanups and enhancements to reduce the areas where we vmalloc
module memory for duplicates, and the respective debug code which
proves the remaining vmalloc pressure comes from userspace.
Most of the changes have been in linux-next for quite some time except
the minor fixes I made to check if a module was already loaded
prior to allocating the final module memory with vmalloc and the
respective debug code it introduces to help clarify the issue. Although
the functional change is small it is rather safe as it can only *help*
reduce vmalloc space for duplicates and is confirmed to fix a bootup
issue with over 400 CPUs with KASAN enabled. I don't expect stable
kernels to pick up that fix as the cleanups would have also had to have
been picked up. Folks on larger CPU systems with modules will want to
just upgrade if vmalloc space has been an issue on bootup.
Given the size of this request, here's some more elaborate details
on this pull request.
The functional change change in this pull request is the very first
patch from Song Liu which replaces the struct module_layout with a new
struct module memory. The old data structure tried to put together all
types of supported module memory types in one data structure, the new
one abstracts the differences in memory types in a module to allow each
one to provide their own set of details. This paves the way in the
future so we can deal with them in a cleaner way. If you look at changes
they also provide a nice cleanup of how we handle these different memory
areas in a module. This change has been in linux-next since before the
merge window opened for v6.3 so to provide more than a full kernel cycle
of testing. It's a good thing as quite a bit of fixes have been found
for it.
Jason Baron then made dynamic debug a first class citizen module user by
using module notifier callbacks to allocate / remove module specific
dynamic debug information.
Nick Alcock has done quite a bit of work cross-tree to remove module
license tags from things which cannot possibly be module at my request
so to:
a) help him with his longer term tooling goals which require a
deterministic evaluation if a piece a symbol code could ever be
part of a module or not. But quite recently it is has been made
clear that tooling is not the only one that would benefit.
Disambiguating symbols also helps efforts such as live patching,
kprobes and BPF, but for other reasons and R&D on this area
is active with no clear solution in sight.
b) help us inch closer to the now generally accepted long term goal
of automating all the MODULE_LICENSE() tags from SPDX license tags
In so far as a) is concerned, although module license tags are a no-op
for non-modules, tools which would want create a mapping of possible
modules can only rely on the module license tag after the commit
8b41fc4454 ("kbuild: create modules.builtin without Makefile.modbuiltin
or tristate.conf"). Nick has been working on this *for years* and
AFAICT I was the only one to suggest two alternatives to this approach
for tooling. The complexity in one of my suggested approaches lies in
that we'd need a possible-obj-m and a could-be-module which would check
if the object being built is part of any kconfig build which could ever
lead to it being part of a module, and if so define a new define
-DPOSSIBLE_MODULE [0]. A more obvious yet theoretical approach I've
suggested would be to have a tristate in kconfig imply the same new
-DPOSSIBLE_MODULE as well but that means getting kconfig symbol names
mapping to modules always, and I don't think that's the case today. I am
not aware of Nick or anyone exploring either of these options. Quite
recently Josh Poimboeuf has pointed out that live patching, kprobes and
BPF would benefit from resolving some part of the disambiguation as
well but for other reasons. The function granularity KASLR (fgkaslr)
patches were mentioned but Joe Lawrence has clarified this effort has
been dropped with no clear solution in sight [1].
In the meantime removing module license tags from code which could never
be modules is welcomed for both objectives mentioned above. Some
developers have also welcomed these changes as it has helped clarify
when a module was never possible and they forgot to clean this up,
and so you'll see quite a bit of Nick's patches in other pull
requests for this merge window. I just picked up the stragglers after
rc3. LWN has good coverage on the motivation behind this work [2] and
the typical cross-tree issues he ran into along the way. The only
concrete blocker issue he ran into was that we should not remove the
MODULE_LICENSE() tags from files which have no SPDX tags yet, even if
they can never be modules. Nick ended up giving up on his efforts due
to having to do this vetting and backlash he ran into from folks who
really did *not understand* the core of the issue nor were providing
any alternative / guidance. I've gone through his changes and dropped
the patches which dropped the module license tags where an SPDX
license tag was missing, it only consisted of 11 drivers. To see
if a pull request deals with a file which lacks SPDX tags you
can just use:
./scripts/spdxcheck.py -f \
$(git diff --name-only commid-id | xargs echo)
You'll see a core module file in this pull request for the above,
but that's not related to his changes. WE just need to add the SPDX
license tag for the kernel/module/kmod.c file in the future but
it demonstrates the effectiveness of the script.
Most of Nick's changes were spread out through different trees,
and I just picked up the slack after rc3 for the last kernel was out.
Those changes have been in linux-next for over two weeks.
The cleanups, debug code I added and final fix I added for modules
were motivated by David Hildenbrand's report of boot failing on
a systems with over 400 CPUs when KASAN was enabled due to running
out of virtual memory space. Although the functional change only
consists of 3 lines in the patch "module: avoid allocation if module is
already present and ready", proving that this was the best we can
do on the modules side took quite a bit of effort and new debug code.
The initial cleanups I did on the modules side of things has been
in linux-next since around rc3 of the last kernel, the actual final
fix for and debug code however have only been in linux-next for about a
week or so but I think it is worth getting that code in for this merge
window as it does help fix / prove / evaluate the issues reported
with larger number of CPUs. Userspace is not yet fixed as it is taking
a bit of time for folks to understand the crux of the issue and find a
proper resolution. Worst come to worst, I have a kludge-of-concept [3]
of how to make kernel_read*() calls for modules unique / converge them,
but I'm currently inclined to just see if userspace can fix this
instead.
[0] https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/
[1] https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com
[2] https://lwn.net/Articles/927569/
[3] https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org
-----BEGIN PGP SIGNATURE-----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=56WK
-----END PGP SIGNATURE-----
Merge tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull module updates from Luis Chamberlain:
"The summary of the changes for this pull requests is:
- Song Liu's new struct module_memory replacement
- Nick Alcock's MODULE_LICENSE() removal for non-modules
- My cleanups and enhancements to reduce the areas where we vmalloc
module memory for duplicates, and the respective debug code which
proves the remaining vmalloc pressure comes from userspace.
Most of the changes have been in linux-next for quite some time except
the minor fixes I made to check if a module was already loaded prior
to allocating the final module memory with vmalloc and the respective
debug code it introduces to help clarify the issue. Although the
functional change is small it is rather safe as it can only *help*
reduce vmalloc space for duplicates and is confirmed to fix a bootup
issue with over 400 CPUs with KASAN enabled. I don't expect stable
kernels to pick up that fix as the cleanups would have also had to
have been picked up. Folks on larger CPU systems with modules will
want to just upgrade if vmalloc space has been an issue on bootup.
Given the size of this request, here's some more elaborate details:
The functional change change in this pull request is the very first
patch from Song Liu which replaces the 'struct module_layout' with a
new 'struct module_memory'. The old data structure tried to put
together all types of supported module memory types in one data
structure, the new one abstracts the differences in memory types in a
module to allow each one to provide their own set of details. This
paves the way in the future so we can deal with them in a cleaner way.
If you look at changes they also provide a nice cleanup of how we
handle these different memory areas in a module. This change has been
in linux-next since before the merge window opened for v6.3 so to
provide more than a full kernel cycle of testing. It's a good thing as
quite a bit of fixes have been found for it.
Jason Baron then made dynamic debug a first class citizen module user
by using module notifier callbacks to allocate / remove module
specific dynamic debug information.
Nick Alcock has done quite a bit of work cross-tree to remove module
license tags from things which cannot possibly be module at my request
so to:
a) help him with his longer term tooling goals which require a
deterministic evaluation if a piece a symbol code could ever be
part of a module or not. But quite recently it is has been made
clear that tooling is not the only one that would benefit.
Disambiguating symbols also helps efforts such as live patching,
kprobes and BPF, but for other reasons and R&D on this area is
active with no clear solution in sight.
b) help us inch closer to the now generally accepted long term goal
of automating all the MODULE_LICENSE() tags from SPDX license tags
In so far as a) is concerned, although module license tags are a no-op
for non-modules, tools which would want create a mapping of possible
modules can only rely on the module license tag after the commit
8b41fc4454 ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf").
Nick has been working on this *for years* and AFAICT I was the only
one to suggest two alternatives to this approach for tooling. The
complexity in one of my suggested approaches lies in that we'd need a
possible-obj-m and a could-be-module which would check if the object
being built is part of any kconfig build which could ever lead to it
being part of a module, and if so define a new define
-DPOSSIBLE_MODULE [0].
A more obvious yet theoretical approach I've suggested would be to
have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as
well but that means getting kconfig symbol names mapping to modules
always, and I don't think that's the case today. I am not aware of
Nick or anyone exploring either of these options. Quite recently Josh
Poimboeuf has pointed out that live patching, kprobes and BPF would
benefit from resolving some part of the disambiguation as well but for
other reasons. The function granularity KASLR (fgkaslr) patches were
mentioned but Joe Lawrence has clarified this effort has been dropped
with no clear solution in sight [1].
In the meantime removing module license tags from code which could
never be modules is welcomed for both objectives mentioned above. Some
developers have also welcomed these changes as it has helped clarify
when a module was never possible and they forgot to clean this up, and
so you'll see quite a bit of Nick's patches in other pull requests for
this merge window. I just picked up the stragglers after rc3. LWN has
good coverage on the motivation behind this work [2] and the typical
cross-tree issues he ran into along the way. The only concrete blocker
issue he ran into was that we should not remove the MODULE_LICENSE()
tags from files which have no SPDX tags yet, even if they can never be
modules. Nick ended up giving up on his efforts due to having to do
this vetting and backlash he ran into from folks who really did *not
understand* the core of the issue nor were providing any alternative /
guidance. I've gone through his changes and dropped the patches which
dropped the module license tags where an SPDX license tag was missing,
it only consisted of 11 drivers. To see if a pull request deals with a
file which lacks SPDX tags you can just use:
./scripts/spdxcheck.py -f \
$(git diff --name-only commid-id | xargs echo)
You'll see a core module file in this pull request for the above, but
that's not related to his changes. WE just need to add the SPDX
license tag for the kernel/module/kmod.c file in the future but it
demonstrates the effectiveness of the script.
Most of Nick's changes were spread out through different trees, and I
just picked up the slack after rc3 for the last kernel was out. Those
changes have been in linux-next for over two weeks.
The cleanups, debug code I added and final fix I added for modules
were motivated by David Hildenbrand's report of boot failing on a
systems with over 400 CPUs when KASAN was enabled due to running out
of virtual memory space. Although the functional change only consists
of 3 lines in the patch "module: avoid allocation if module is already
present and ready", proving that this was the best we can do on the
modules side took quite a bit of effort and new debug code.
The initial cleanups I did on the modules side of things has been in
linux-next since around rc3 of the last kernel, the actual final fix
for and debug code however have only been in linux-next for about a
week or so but I think it is worth getting that code in for this merge
window as it does help fix / prove / evaluate the issues reported with
larger number of CPUs. Userspace is not yet fixed as it is taking a
bit of time for folks to understand the crux of the issue and find a
proper resolution. Worst come to worst, I have a kludge-of-concept [3]
of how to make kernel_read*() calls for modules unique / converge
them, but I'm currently inclined to just see if userspace can fix this
instead"
Link: https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [0]
Link: https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [1]
Link: https://lwn.net/Articles/927569/ [2]
Link: https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org [3]
* tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (121 commits)
module: add debugging auto-load duplicate module support
module: stats: fix invalid_mod_bytes typo
module: remove use of uninitialized variable len
module: fix building stats for 32-bit targets
module: stats: include uapi/linux/module.h
module: avoid allocation if module is already present and ready
module: add debug stats to help identify memory pressure
module: extract patient module check into helper
modules/kmod: replace implementation with a semaphore
Change DEFINE_SEMAPHORE() to take a number argument
module: fix kmemleak annotations for non init ELF sections
module: Ignore L0 and rename is_arm_mapping_symbol()
module: Move is_arm_mapping_symbol() to module_symbol.h
module: Sync code of is_arm_mapping_symbol()
scripts/gdb: use mem instead of core_layout to get the module address
interconnect: remove module-related code
interconnect: remove MODULE_LICENSE in non-modules
zswap: remove MODULE_LICENSE in non-modules
zpool: remove MODULE_LICENSE in non-modules
x86/mm/dump_pagetables: remove MODULE_LICENSE in non-modules
...
The console tracepoint is used by kcsan/kasan/kfence/kmsan test modules.
Since this tracepoint is not exported, these modules iterate over all
available tracepoints to find the console trace point. Export the trace
point so that it can be directly used.
Link: https://lkml.kernel.org/r/20230413100859.1492323-1-quic_pkondeti@quicinc.com
Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Marco Elver <elver@google.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Linus Torvalds
Justin Stitt
Sreenath Vijayan
Tony Lindgren
John Ogness
Peter Collingbourne
Baoquan He
Petr Mladek
Jingzi Meng
Li kunyu
Thomas Gleixner
Christoph Hellwig
Enlin Mu
Peter Zijlstra
Pavankumar Kondeti