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Linux kernel
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In order to build the documentation, use ``make htmldocs`` or
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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 Kbuild fixes from Masahiro Yamada:
- do not use non-portable strsep() in a host program
- fix single target builds for external modules
- change Clang's --prefix option to make it work for the latest Clang
* tag 'kbuild-fixes-v5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
Makefile: Fix GCC_TOOLCHAIN_DIR prefix for Clang cross compilation
kbuild: fix single target builds for external modules
modpost: remove use of non-standard strsep() in HOSTCC code
Pull parisc fixes from Helge Deller:
"Two fixes:
- Add the cmpxchg() function for pointers to u8 values. This fixes a
kernel linking error when building the tusb1210 driver (from Liam
Beguin).
- Add a define for atomic64_set_release() to fix CPU soft lockups
which happen because of missing unlocks while processing bit
operations (from John David Anglin)"
* 'parisc-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Add atomic64_set_release() define to avoid CPU soft lockups
parisc: add support for cmpxchg on u8 pointers
When CROSS_COMPILE is set (e.g. aarch64-linux-gnu-), if
$(CROSS_COMPILE)elfedit is found at /usr/bin/aarch64-linux-gnu-elfedit,
GCC_TOOLCHAIN_DIR will be set to /usr/bin/. --prefix= will be set to
/usr/bin/ and Clang as of 11 will search for both
$(prefix)aarch64-linux-gnu-$needle and $(prefix)$needle.
GCC searchs for $(prefix)aarch64-linux-gnu/$version/$needle,
$(prefix)aarch64-linux-gnu/$needle and $(prefix)$needle. In practice,
$(prefix)aarch64-linux-gnu/$needle rarely contains executables.
To better model how GCC's -B/--prefix takes in effect in practice, newer
Clang (since
https://github.com/llvm/llvm-project/commit/3452a0d8c17f7166f479706b293caf6ac76ffd90)
only searches for $(prefix)$needle. Currently it will find /usr/bin/as
instead of /usr/bin/aarch64-linux-gnu-as.
Set --prefix= to $(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
(/usr/bin/aarch64-linux-gnu-) so that newer Clang can find the
appropriate cross compiling GNU as (when -no-integrated-as is in
effect).
Cc: stable@vger.kernel.org
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1099
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull char/misc driver fixes from Greg KH:
"Here are a few small driver fixes for 5.8-rc7
They include:
- habanalabs fixes
- tiny fpga driver fixes
- /dev/mem fixup from previous changes
- interconnect driver fixes
- binder fix
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
interconnect: msm8916: Fix buswidth of pcnoc_s nodes
interconnect: Do not skip aggregation for disabled paths
/dev/mem: Add missing memory barriers for devmem_inode
binder: Don't use mmput() from shrinker function.
habanalabs: prevent possible out-of-bounds array access
fpga: dfl: fix bug in port reset handshake
fpga: dfl: pci: reduce the scope of variable 'ret'
habanalabs: set 4s timeout for message to device CPU
habanalabs: set clock gating per engine
habanalabs: block WREG_BULK packet on PDMA
Stalls are quite frequent with recent kernels. I enabled
CONFIG_SOFTLOCKUP_DETECTOR and I caught the following stall:
watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [cc1:22803]
CPU: 0 PID: 22803 Comm: cc1 Not tainted 5.6.17+ #3
Hardware name: 9000/800/rp3440
IAOQ[0]: d_alloc_parallel+0x384/0x688
IAOQ[1]: d_alloc_parallel+0x388/0x688
RP(r2): d_alloc_parallel+0x134/0x688
Backtrace:
[<000000004036974c>] __lookup_slow+0xa4/0x200
[<0000000040369fc8>] walk_component+0x288/0x458
[<000000004036a9a0>] path_lookupat+0x88/0x198
[<000000004036e748>] filename_lookup+0xa0/0x168
[<000000004036e95c>] user_path_at_empty+0x64/0x80
[<000000004035d93c>] vfs_statx+0x104/0x158
[<000000004035dfcc>] __do_sys_lstat64+0x44/0x80
[<000000004035e5a0>] sys_lstat64+0x20/0x38
[<0000000040180054>] syscall_exit+0x0/0x14
The code was stuck in this loop in d_alloc_parallel:
4037d414: 0e 00 10 dc ldd 0(r16),ret0
4037d418: c7 fc 5f ed bb,< ret0,1f,4037d414 <d_alloc_parallel+0x384>
4037d41c: 08 00 02 40 nop
This is the inner loop of bit_spin_lock which is called by hlist_bl_unlock in
d_alloc_parallel:
static inline void bit_spin_lock(int bitnum, unsigned long *addr)
{
/*
* Assuming the lock is uncontended, this never enters
* the body of the outer loop. If it is contended, then
* within the inner loop a non-atomic test is used to
* busywait with less bus contention for a good time to
* attempt to acquire the lock bit.
*/
preempt_disable();
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
while (unlikely(test_and_set_bit_lock(bitnum, addr))) {
preempt_enable();
do {
cpu_relax();
} while (test_bit(bitnum, addr));
preempt_disable();
}
#endif
__acquire(bitlock);
}
After consideration, I realized that we must be losing bit unlocks.
Then, I noticed that we missed defining atomic64_set_release().
Adding this define fixes the stalls in bit operations.
Signed-off-by: Dave Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Commit f566e1fbadb6 ("kbuild: make multiple directory targets work")
broke single target builds for external modules. Fix this.
Fixes: f566e1fbadb6 ("kbuild: make multiple directory targets work")
Reported-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Bjørn Mork <bjorn@mork.no>
Pull driver core fix from Greg KH:
"A single driver core fix for 5.8-rc7. It resolves a problem found in
the previous fix for this code made in 5.8-rc6. Hopefully this is all
now cleared up, as this seems to be the last of the reported issues in
this area, and was tested on the problem hardware.
This patch has been in linux-next with no reported problems"
* tag 'driver-core-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
device property: Avoid NULL pointer dereference in device_get_next_child_node()
The buswidth of the pcnoc_s_* nodes is actually not 8, but
4 bytes. Let's fix it.
Reported-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Mike Tipton <mdtipton@codeaurora.org>
Fixes: 30c8fa3ec61a ("interconnect: qcom: Add MSM8916 interconnect provider driver")
Link: https://lore.kernel.org/r/20200709130004.12462-1-georgi.djakov@linaro.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200723083735.5616-3-georgi.djakov@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The kernel test bot reported[1] that using set_mask_bits on a u8 causes
the following issue on parisc:
hppa-linux-ld: drivers/phy/ti/phy-tusb1210.o: in function `tusb1210_probe':
>> (.text+0x2f4): undefined reference to `__cmpxchg_called_with_bad_pointer'
>> hppa-linux-ld: (.text+0x324): undefined reference to `__cmpxchg_called_with_bad_pointer'
hppa-linux-ld: (.text+0x354): undefined reference to `__cmpxchg_called_with_bad_pointer'
Add support for cmpxchg on u8 pointers.
[1] https://lore.kernel.org/patchwork/patch/1272617/#1468946
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Liam Beguin <liambeguin@gmail.com>
Tested-by: Dave Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
strsep() is neither standard C nor POSIX and used outside
the kernel code here. Using it here requires that the
build host supports it out of the box which is e.g.
not true for a Darwin build host and using a cross-compiler.
This leads to:
scripts/mod/modpost.c:145:2: warning: implicit declaration of function 'strsep' [-Wimplicit-function-declaration]
return strsep(stringp, "\n");
^
and a segfault when running MODPOST.
See also: https://stackoverflow.com/a/7219504
So let's replace this by strchr() instead of using strsep().
It does not hurt kernel size or speed since this code is run
on the build host.
Fixes: ac5100f5432967 ("modpost: add read_text_file() and get_line() helpers")
Co-developed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull staging driver fixes from Greg KH:
"Five small staging driver fixes for 5.8-rc7 to resolve some reported
problems:
- four comedi driver fixes for problems found with them
- a syzbot-found fix for the wlang-ng driver that resolves a much
reported problem.
All of these have been in linux-next with no reported issues"
* tag 'staging-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: wlan-ng: properly check endpoint types
staging: comedi: addi_apci_1564: check INSN_CONFIG_DIGITAL_TRIG shift
staging: comedi: addi_apci_1500: check INSN_CONFIG_DIGITAL_TRIG shift
staging: comedi: addi_apci_1032: check INSN_CONFIG_DIGITAL_TRIG shift
staging: comedi: ni_6527: fix INSN_CONFIG_DIGITAL_TRIG support
When we have no primary fwnode or when it's a software node, we may end up
in the situation when fwnode is a NULL pointer. There is no point to look for
secondary fwnode in such case. Add a necessary check to a condition.
Fixes: 114dbb4fa7c4 ("drivers property: When no children in primary, try secondary")
Reported-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20200716182747.54929-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When an interconnect path is being disabled, currently we don't aggregate
the requests for it afterwards. But the re-aggregation step shouldn't be
skipped, as it may leave the nodes with outdated bandwidth data. This
outdated data may actually keep the path still enabled and prevent the
device from going into lower power states.
Reported-by: Atul Dhudase <adhudase@codeaurora.org>
Fixes: 7d374b209083 ("interconnect: Add helpers for enabling/disabling a path")
Reviewed-by: Sibi Sankar <sibis@codeaurora.org>
Tested-by: Atul Dhudase <adhudase@codeaurora.org>
Reviewed-by: Atul Dhudase <adhudase@codeaurora.org>
Link: https://lore.kernel.org/r/20200721120740.3436-1-georgi.djakov@linaro.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Link: https://lore.kernel.org/r/20200723083735.5616-2-georgi.djakov@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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