tjh.dev
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
code
Clone this repository
https://tangled.org/tjh.dev/kernel
git@gordian.tjh.dev:tjh.dev/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Pull ide fix from Jens Axboe:
"This is a leftover fix from 5.11, where I forgot to ship it your way"
* tag 'ide-5.11-2021-02-28' of git://git.kernel.dk/linux-block:
ide/falconide: Fix module unload
Pull Kbuild fixes from Masahiro Yamada:
- Fix UNUSED_KSYMS_WHITELIST for Clang LTO
- Make -s builds really silent irrespective of V= option
- Fix build error when SUBLEVEL or PATCHLEVEL is empty
* tag 'kbuild-fixes-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: Fix <linux/version.h> for empty SUBLEVEL or PATCHLEVEL again
kbuild: make -s option take precedence over V=1
ia64: remove redundant READELF from arch/ia64/Makefile
kbuild: do not include include/config/auto.conf from adjust_autoksyms.sh
kbuild: fix UNUSED_KSYMS_WHITELIST for Clang LTO
kbuild: lto: add _mcount to list of used symbols
Unloading the falconide module results in a crash:
Unable to handle kernel NULL pointer dereference at virtual address 00000000
Oops: 00000000
Modules linked in: falconide(-)
PC: [<002930b2>] ide_host_remove+0x2e/0x1d2
SR: 2000 SP: 00b49e28 a2: 009b0f90
d0: 00000000 d1: 009b0f90 d2: 00000000 d3: 00b48000
d4: 003cef32 d5: 00299188 a0: 0086d000 a1: 0086d000
Process rmmod (pid: 322, task=009b0f90)
Frame format=7 eff addr=00000000 ssw=0505 faddr=00000000
wb 1 stat/addr/data: 0000 00000000 00000000
wb 2 stat/addr/data: 0000 00000000 00000000
wb 3 stat/addr/data: 0000 00000000 00018da9
push data: 00000000 00000000 00000000 00000000
Stack from 00b49e90:
004c456a 0027f176 0027cb0a 0027cb9e 00000000 0086d00a 2187d3f0 0027f0e0
00b49ebc 2187d1f6 00000000 00b49ec8 002811e8 0086d000 00b49ef0 0028024c
0086d00a 002800d6 00279a1a 00000001 00000001 0086d00a 2187d3f0 00279a58
00b49f1c 002802e0 0086d00a 2187d3f0 004c456a 0086d00a ef96af74 00000000
2187d3f0 002805d2 800de064 00b49f44 0027f088 2187d3f0 00ac1cf4 2187d3f0
004c43be 2187d3f0 00000000 2187d3f0 800b66a8 00b49f5c 00280776 2187d3f0
Call Trace: [<0027f176>] __device_driver_unlock+0x0/0x48
[<0027cb0a>] device_links_busy+0x0/0x94
[<0027cb9e>] device_links_unbind_consumers+0x0/0x130
[<0027f0e0>] __device_driver_lock+0x0/0x5a
[<2187d1f6>] falconide_remove+0x12/0x18 [falconide]
[<002811e8>] platform_drv_remove+0x1c/0x28
[<0028024c>] device_release_driver_internal+0x176/0x17c
[<002800d6>] device_release_driver_internal+0x0/0x17c
[<00279a1a>] get_device+0x0/0x22
[<00279a58>] put_device+0x0/0x18
[<002802e0>] driver_detach+0x56/0x82
[<002805d2>] driver_remove_file+0x0/0x24
[<0027f088>] bus_remove_driver+0x4c/0xa4
[<00280776>] driver_unregister+0x28/0x5a
[<00281a00>] platform_driver_unregister+0x12/0x18
[<2187d2a0>] ide_falcon_driver_exit+0x10/0x16 [falconide]
[<000764f0>] sys_delete_module+0x110/0x1f2
[<000e83ea>] sys_rename+0x1a/0x1e
[<00002e0c>] syscall+0x8/0xc
[<00188004>] ext4_multi_mount_protect+0x35a/0x3ce
Code: 0029 9188 4bf9 0027 aa1c 283c 003c ef32 <265c> 4a8b 6700 00b8 2043 2028 000c 0280 00ff ff00 6600 0176 40c0 7202 b2b9 004c
Disabling lock debugging due to kernel taint
This happens because the driver_data pointer is uninitialized.
Add the missing platform_set_drvdata() call. For clarity, use the
matching platform_get_drvdata() as well.
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Fixes: 5ed0794cde593 ("m68k/atari: Convert Falcon IDE drivers to platform drivers")
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull arch/csky updates from Guo Ren:
"Features:
- add new memory layout 2.5G(user):1.5G(kernel)
- add kmemleak support
- reconstruct VDSO framework: add VDSO with GENERIC_GETTIMEOFDAY,
GENERIC_TIME_VSYSCALL, HAVE_GENERIC_VDSO
- add faulthandler_disabled() check
- support (fix) swapon
- add (fix) _PAGE_ACCESSED for default pgprot
- abort uaccess retries upon fatal signal (from arm)
Fixes and optimizations:
- fix perf probe failure
- fix show_regs doesn't contain regs->usp
- remove custom asm/atomic.h implementation
- fix barrier design
- fix futex SMP implementation
- fix asm/cmpxchg.h with correct ordering barrier
- cleanup asm/spinlock.h
- fix PTE global for 2.5:1.5 virtual memory
- remove prologue of page fault handler in entry.S
- fix TLB maintenance synchronization problem
- add show_tlb for CPU_CK860 debug
- fix FAULT_FLAG_XXX param for handle_mm_fault
- fix update_mmu_cache called with user io mapping
- fix do_page_fault parent irq status
- fix a size determination in gpr_get()
- pgtable.h: Coding convention
- kprobe: Fix code in simulate without 'long'
- fix pfn_valid error with wrong max_mapnr
- use free_initmem_default() in free_initmem()
- fix compile error"
* tag 'csky-for-linus-5.12-rc1' of git://github.com/c-sky/csky-linux: (30 commits)
csky: Fixup compile error
csky: use free_initmem_default() in free_initmem()
csky: Fixup pfn_valid error with wrong max_mapnr
csky: Add VDSO with GENERIC_GETTIMEOFDAY, GENERIC_TIME_VSYSCALL, HAVE_GENERIC_VDSO
csky: kprobe: Fixup code in simulate without 'long'
csky: Fixup swapon
csky: pgtable.h: Coding convention
csky: Fixup _PAGE_ACCESSED for default pgprot
csky: remove unused including <linux/version.h>
csky: Fix a size determination in gpr_get()
csky: Reconstruct VDSO framework
csky: mm: abort uaccess retries upon fatal signal
csky: Sync riscv mm/fault.c for easy maintenance
csky: Fixup do_page_fault parent irq status
csky: Add faulthandler_disabled() check
csky: Fixup update_mmu_cache called with user io mapping
csky: Fixup FAULT_FLAG_XXX param for handle_mm_fault
csky: Add show_tlb for CPU_CK860 debug
csky: Fix TLB maintenance synchronization problem
csky: Add kmemleak support
...
Commit 78d3bb4483ba ("kbuild: Fix <linux/version.h> for empty SUBLEVEL
or PATCHLEVEL") fixed the build error for empty SUBLEVEL or PATCHLEVEL
by prepending a zero.
Commit 9b82f13e7ef3 ("kbuild: clamp SUBLEVEL to 255") re-introduced
this issue.
This time, we cannot take the same approach because we have C code:
#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL)
#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
Replace empty SUBLEVEL/PATCHLEVEL with a zero.
Fixes: 9b82f13e7ef3 ("kbuild: clamp SUBLEVEL to 255")
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-and-tested-by: Sasha Levin <sashal@kernel.org>
Pull s390 cleanups from Vasily Gorbik:
"Update defconfigs and sort config select list"
* tag 's390-5.11-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/Kconfig: sort config S390 select list once again
s390: update defconfigs
Pull more RISC-V updates from Palmer Dabbelt:
"A pair of patches that slipped through the cracks:
- enable CPU hotplug in the defconfigs
- some cleanups to setup_bootmem
There's also a single fix for some randconfig build failures:
- make NUMA depend on SMP"
* tag 'riscv-for-linus-5.12-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: Cleanup setup_bootmem()
RISC-V: Enable CPU Hotplug in defconfigs
RISC-V: Make NUMA depend on SMP
: error: C++ style comments are not allowed in ISO C90
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
^
error: (this will be reported only once per input file)
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
'make -s' should be really silent. However, 'make -s V=1' prints noisy
log messages from some shell scripts.
Of course, such a combination is odd, but the build system needs to do
the right thing even if a user gives strange input.
If -s is given, KBUILD_VERBOSE should be forced to 0.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull power management fixes from Rafael Wysocki:
"These fix a crash in intel_pstate during resume from suspend-to-RAM
that may occur after recent changes and two resource leaks in error
paths in the operating performance points (OPP) framework, add a new
C-states table to intel_idle and update the cpuidle MAINTAINERS entry
to cover the governors too.
Specifics:
- Fix recently introduced crash in the intel_pstate driver that
occurs if scale-invariance is disabled during resume from
suspend-to-RAM due to inconsistent changes of APERF or MPERF MSR
values made by the platform firmware (Rafael Wysocki).
- Fix a memory leak and add a missing clk_put() in error paths in the
OPP framework (Quanyang Wang, Viresh Kumar).
- Add new C-states table for SnowRidge processors to the intel_idle
driver (Artem Bityutskiy).
- Update the MAINTAINERS entry for cpuidle to make it clear that the
governors are covered by it too (Lukas Bulwahn)"
* tag 'pm-5.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
intel_idle: add SnowRidge C-state table
cpufreq: intel_pstate: Fix fast-switch fallback path
opp: Call the missing clk_put() on error
opp: fix memory leak in _allocate_opp_table
MAINTAINERS: include governors into CPU IDLE TIME MANAGEMENT FRAMEWORK
...and add comments at the top and bottom.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Pull more SCSI updates from James Bottomley:
"This is a few driver updates (iscsi, mpt3sas) that were still in the
staging queue when the merge window opened (all committed on or before
8 Feb) and some small bug fixes which came in during the merge window
(all committed on 22 Feb)"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (30 commits)
scsi: hpsa: Correct dev cmds outstanding for retried cmds
scsi: sd: Fix Opal support
scsi: target: tcmu: Fix memory leak caused by wrong uio usage
scsi: target: tcmu: Move some functions without code change
scsi: sd: sd_zbc: Don't pass GFP_NOIO to kvcalloc
scsi: aic7xxx: Remove unused function pointer typedef ahc_bus_suspend/resume_t
scsi: bnx2fc: Fix Kconfig warning & CNIC build errors
scsi: ufs: Fix a duplicate dev quirk number
scsi: aic79xx: Fix spelling of version
scsi: target: core: Prevent underflow for service actions
scsi: target: core: Add cmd length set before cmd complete
scsi: iscsi: Drop session lock in iscsi_session_chkready()
scsi: qla4xxx: Use iscsi_is_session_online()
scsi: libiscsi: Reset max/exp cmdsn during recovery
scsi: iscsi_tcp: Fix shost can_queue initialization
scsi: libiscsi: Add helper to calculate max SCSI cmds per session
scsi: libiscsi: Fix iSCSI host workq destruction
scsi: libiscsi: Fix iscsi_task use after free()
scsi: libiscsi: Drop taskqueuelock
scsi: libiscsi: Fix iscsi_prep_scsi_cmd_pdu() error handling
...
After the following patches,
commit de043da0b9e7 ("RISC-V: Fix usage of memblock_enforce_memory_limit")
commit 1bd14a66ee52 ("RISC-V: Remove any memblock representing unusable memory area")
commit b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()")
some logic is useless, kill the mem_start/start/end and unneeded code.
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
README