tjh.dev
Linux kernel
============
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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.
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Pull RISC-V fixes from Paul Walmsley:
"Several fixes for RISC-V:
- Fix function graph trace support
- Prefix the CSR IRQ_* macro names with "RV_", to avoid collisions
with macros elsewhere in the Linux kernel tree named "IRQ_TIMER"
- Use __pa_symbol() when computing the physical address of a kernel
symbol, rather than __pa()
- Mark the RISC-V port as supporting GCOV
One DT addition:
- Describe the L2 cache controller in the FU540 DT file
One documentation update:
- Add patch acceptance guideline documentation"
* tag 'riscv/for-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
Documentation: riscv: add patch acceptance guidelines
riscv: prefix IRQ_ macro names with an RV_ namespace
clocksource: riscv: add notrace to riscv_sched_clock
riscv: ftrace: correct the condition logic in function graph tracer
riscv: dts: Add DT support for SiFive L2 cache controller
riscv: gcov: enable gcov for RISC-V
riscv: mm: use __pa_symbol for kernel symbols
Merge misc fixes from Andrew Morton:
"17 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
hexagon: define ioremap_uc
ocfs2: fix the crash due to call ocfs2_get_dlm_debug once less
ocfs2: call journal flush to mark journal as empty after journal recovery when mount
mm/hugetlb: defer freeing of huge pages if in non-task context
mm/gup: fix memory leak in __gup_benchmark_ioctl
mm/oom: fix pgtables units mismatch in Killed process message
fs/posix_acl.c: fix kernel-doc warnings
hexagon: work around compiler crash
hexagon: parenthesize registers in asm predicates
fs/namespace.c: make to_mnt_ns() static
fs/nsfs.c: include headers for missing declarations
fs/direct-io.c: include fs/internal.h for missing prototype
mm: move_pages: return valid node id in status if the page is already on the target node
memcg: account security cred as well to kmemcg
kcov: fix struct layout for kcov_remote_arg
mm/zsmalloc.c: fix the migrated zspage statistics.
mm/memory_hotplug: shrink zones when offlining memory
Formalize, in kernel documentation, the patch acceptance policy for
arch/riscv. In summary, it states that as maintainers, we plan to
only accept patches for new modules or extensions that have been
frozen or ratified by the RISC-V Foundation.
We've been following these guidelines for the past few months. In the
meantime, we've received quite a bit of feedback that it would be
helpful to have these guidelines formally documented.
Based on a suggestion from Matthew Wilcox, we also add a link to this
file to Documentation/process/index.rst, to make this document easier
to find. The format of this document has also been changed to align
to the format outlined in the maintainer entry profiles, in accordance
with comments from Jon Corbet and Dan Williams.
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Krste Asanovic <krste@berkeley.edu>
Cc: Andrew Waterman <waterman@eecs.berkeley.edu>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Pull apparmor fixes from John Johansen:
- performance regression: only get a label reference if the fast path
check fails
- fix aa_xattrs_match() may sleep while holding a RCU lock
- fix bind mounts aborting with -ENOMEM
* tag 'apparmor-pr-2020-01-04' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
apparmor: fix aa_xattrs_match() may sleep while holding a RCU lock
apparmor: only get a label reference if the fast path check fails
apparmor: fix bind mounts aborting with -ENOMEM
Similar to commit 38e45d81d14e ("sparc64: implement ioremap_uc") define
ioremap_uc for hexagon to avoid errors from
-Wimplicit-function-definition.
Link: http://lkml.kernel.org/r/20191209222956.239798-2-ndesaulniers@google.com
Link: https://github.com/ClangBuiltLinux/linux/issues/797
Fixes: e537654b7039 ("lib: devres: add a helper function for ioremap_uc")
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Brian Cain <bcain@codeaurora.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Tuowen Zhao <ztuowen@gmail.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexios Zavras <alexios.zavras@intel.com>
Cc: Allison Randal <allison@lohutok.net>
Cc: Will Deacon <will@kernel.org>
Cc: Richard Fontana <rfontana@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
"IRQ_TIMER", used in the arch/riscv CSR header file, is a sufficiently
generic macro name that it's used by several source files across the
Linux code base. Some of these other files ultimately include the
arch/riscv CSR include file, causing collisions. Fix by prefixing the
RISC-V csr.h IRQ_ macro names with an RV_ prefix.
Fixes: a4c3733d32a72 ("riscv: abstract out CSR names for supervisor vs machine mode")
Reported-by: Olof Johansson <olof@lixom.net>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Pull MIPS fixes from Paul Burton:
"A collection of MIPS fixes:
- Fill the struct cacheinfo shared_cpu_map field with sensible
values, notably avoiding issues with perf which was unhappy in the
absence of these values.
- A boot fix for Loongson 2E & 2F machines which was fallout from
some refactoring performed this cycle.
- A Kconfig dependency fix for the Loongson CPU HWMon driver.
- A couple of VDSO fixes, ensuring gettimeofday() behaves
appropriately for kernel configurations that don't include support
for a clocksource the VDSO can use & fixing the calling convention
for the n32 & n64 VDSOs which would previously clobber the $gp/$28
register.
- A build fix for vmlinuz compressed images which were
inappropriately building with -fsanitize-coverage despite not being
part of the kernel proper, then failing to link due to the missing
__sanitizer_cov_trace_pc() function.
- A couple of eBPF JIT fixes, including disabling it for MIPS32 due
to a large number of issues with the code generated there &
reflecting ISA dependencies in Kconfig to enforce that systems
which don't support the JIT must include the interpreter"
* tag 'mips_fixes_5.5_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MIPS: Avoid VDSO ABI breakage due to global register variable
MIPS: BPF: eBPF JIT: check for MIPS ISA compliance in Kconfig
MIPS: BPF: Disable MIPS32 eBPF JIT
MIPS: Prevent link failure with kcov instrumentation
MIPS: Kconfig: Use correct form for 'depends on'
mips: Fix gettimeofday() in the vdso library
MIPS: Fix boot on Fuloong2 systems
mips: cacheinfo: report shared CPU map
aa_xattrs_match() is unfortunately calling vfs_getxattr_alloc() from a
context protected by an rcu_read_lock. This can not be done as
vfs_getxattr_alloc() may sleep regardles of the gfp_t value being
passed to it.
Fix this by breaking the rcu_read_lock on the policy search when the
xattr match feature is requested and restarting the search if a policy
changes occur.
Fixes: 8e51f9087f40 ("apparmor: Add support for attaching profiles via xattr, presence and value")
Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Because ocfs2_get_dlm_debug() function is called once less here, ocfs2
file system will trigger the system crash, usually after ocfs2 file
system is unmounted.
This system crash is caused by a generic memory corruption, these crash
backtraces are not always the same, for exapmle,
ocfs2: Unmounting device (253,16) on (node 172167785)
general protection fault: 0000 [#1] SMP PTI
CPU: 3 PID: 14107 Comm: fence_legacy Kdump:
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:__kmalloc+0xa5/0x2a0
Code: 00 00 4d 8b 07 65 4d 8b
RSP: 0018:ffffaa1fc094bbe8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: d310a8800d7a3faf RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000dc0 RDI: ffff96e68fc036c0
RBP: d310a8800d7a3faf R08: ffff96e6ffdb10a0 R09: 00000000752e7079
R10: 000000000001c513 R11: 0000000004091041 R12: 0000000000000dc0
R13: 0000000000000039 R14: ffff96e68fc036c0 R15: ffff96e68fc036c0
FS: 00007f699dfba540(0000) GS:ffff96e6ffd80000(0000) knlGS:00000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f3a9d9b768 CR3: 000000002cd1c000 CR4: 00000000000006e0
Call Trace:
ext4_htree_store_dirent+0x35/0x100 [ext4]
htree_dirblock_to_tree+0xea/0x290 [ext4]
ext4_htree_fill_tree+0x1c1/0x2d0 [ext4]
ext4_readdir+0x67c/0x9d0 [ext4]
iterate_dir+0x8d/0x1a0
__x64_sys_getdents+0xab/0x130
do_syscall_64+0x60/0x1f0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f699d33a9fb
This regression problem was introduced by commit e581595ea29c ("ocfs: no
need to check return value of debugfs_create functions").
Link: http://lkml.kernel.org/r/20191225061501.13587-1-ghe@suse.com
Fixes: e581595ea29c ("ocfs: no need to check return value of debugfs_create functions")
Signed-off-by: Gang He <ghe@suse.com>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org> [5.3+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When enabling ftrace graph tracer, it gets the tracing clock in
ftrace_push_return_trace(). Eventually, it invokes riscv_sched_clock()
to get the clock value. If riscv_sched_clock() isn't marked with
'notrace', it will call ftrace_push_return_trace() and cause infinite
loop.
The result of failure as follow:
command: echo function_graph >current_tracer
[ 46.176787] Unable to handle kernel paging request at virtual address ffffffe04fb38c48
[ 46.177309] Oops [#1]
[ 46.177478] Modules linked in:
[ 46.177770] CPU: 0 PID: 256 Comm: $d Not tainted 5.5.0-rc1 #47
[ 46.177981] epc: ffffffe00035e59a ra : ffffffe00035e57e sp : ffffffe03a7569b0
[ 46.178216] gp : ffffffe000d29b90 tp : ffffffe03a756180 t0 : ffffffe03a756968
[ 46.178430] t1 : ffffffe00087f408 t2 : ffffffe03a7569a0 s0 : ffffffe03a7569f0
[ 46.178643] s1 : ffffffe00087f408 a0 : 0000000ac054cda4 a1 : 000000000087f411
[ 46.178856] a2 : 0000000ac054cda4 a3 : 0000000000373ca0 a4 : ffffffe04fb38c48
[ 46.179099] a5 : 00000000153e22a8 a6 : 00000000005522ff a7 : 0000000000000005
[ 46.179338] s2 : ffffffe03a756a90 s3 : ffffffe00032811c s4 : ffffffe03a756a58
[ 46.179570] s5 : ffffffe000d29fe0 s6 : 0000000000000001 s7 : 0000000000000003
[ 46.179809] s8 : 0000000000000003 s9 : 0000000000000002 s10: 0000000000000004
[ 46.180053] s11: 0000000000000000 t3 : 0000003fc815749c t4 : 00000000000efc90
[ 46.180293] t5 : ffffffe000d29658 t6 : 0000000000040000
[ 46.180482] status: 0000000000000100 badaddr: ffffffe04fb38c48 cause: 000000000000000f
Signed-off-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[paul.walmsley@sifive.com: cleaned up patch description]
Fixes: 92e0d143fdef ("clocksource/drivers/riscv_timer: Provide the sched_clock")
Cc: stable@vger.kernel.org
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Pull dmaengine fixes from Vinod Koul:
"A bunch of fixes for:
- uninitialized dma_slave_caps access
- virt-dma use after free in vchan_complete()
- driver fixes for ioat, k3dma and jz4780"
* tag 'dmaengine-fix-5.5-rc5' of git://git.infradead.org/users/vkoul/slave-dma:
ioat: ioat_alloc_ring() failure handling.
dmaengine: virt-dma: Fix access after free in vchan_complete()
dmaengine: k3dma: Avoid null pointer traversal
dmaengine: dma-jz4780: Also break descriptor chains on JZ4725B
dmaengine: Fix access to uninitialized dma_slave_caps
Declaring __current_thread_info as a global register variable has the
effect of preventing GCC from saving & restoring its value in cases
where the ABI would typically do so.
To quote GCC documentation:
> If the register is a call-saved register, call ABI is affected: the
> register will not be restored in function epilogue sequences after the
> variable has been assigned. Therefore, functions cannot safely return
> to callers that assume standard ABI.
When our position independent VDSO is built for the n32 or n64 ABIs all
functions it exposes should be preserving the value of $gp/$28 for their
caller, but in the presence of the __current_thread_info global register
variable GCC stops doing so & simply clobbers $gp/$28 when calculating
the address of the GOT.
In cases where the VDSO returns success this problem will typically be
masked by the caller in libc returning & restoring $gp/$28 itself, but
that is by no means guaranteed. In cases where the VDSO returns an error
libc will typically contain a fallback path which will now fail
(typically with a bad memory access) if it attempts anything which
relies upon the value of $gp/$28 - eg. accessing anything via the GOT.
One fix for this would be to move the declaration of
__current_thread_info inside the current_thread_info() function,
demoting it from global register variable to local register variable &
avoiding inadvertently creating a non-standard calling ABI for the VDSO.
Unfortunately this causes issues for clang, which doesn't support local
register variables as pointed out by commit fe92da0f355e ("MIPS: Changed
current_thread_info() to an equivalent supported by both clang and GCC")
which introduced the global register variable before we had a VDSO to
worry about.
Instead, fix this by continuing to use the global register variable for
the kernel proper but declare __current_thread_info as a simple extern
variable when building the VDSO. It should never be referenced, and will
cause a link error if it is. This resolves the calling convention issue
for the VDSO without having any impact upon the build of the kernel
itself for either clang or gcc.
Signed-off-by: Paul Burton <paulburton@kernel.org>
Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Brauner <christian.brauner@canonical.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: <stable@vger.kernel.org> # v4.4+
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
The common fast path check can be done under rcu_read_lock() and
doesn't need a reference count on the label. Only take a reference
count if entering the slow path.
Fixes reported hackbench regression
- sha1 79e178a57dae ("Merge tag 'apparmor-pr-2019-12-03' of
git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor")
hackbench -l (256000/#grp) -g #grp
128 groups 19.679 ±0.90%
- previous sha1 01d1dff64662 ("Merge tag 's390-5.5-2' of
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux")
hackbench -l (256000/#grp) -g #grp
128 groups 3.1689 ±3.04%
Reported-by: Vincent Guittot <vincent.guittot@linaro.org>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Fixes: bce4e7e9c45e ("apparmor: reduce rcu_read_lock scope for aa_file_perm mediation")
Signed-off-by: John Johansen <john.johansen@canonical.com>
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