Newer ISA versions are enabled by clearing all bits in the PCR
associated with previous versions of the ISA. Enable ISA v3.1 support
by updating the PCR mask to include ISA v3.0. This ensures all PCR
bits corresponding to earlier architecture versions get cleared
thereby enabling ISA v3.1 if supported by the hardware.
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200521014341.29095-3-alistair@popple.id.au
POWER10 introduces two new architectural features - ISAv3.1 and matrix
multiply assist (MMA) instructions. Userspace detects the presence
of these features via two HWCAP bits introduced in this patch. These
bits have been agreed to by the compiler and binutils team.
According to ISAv3.1 MMA is an optional feature and software that makes
use of it should first check for availability via this HWCAP bit and use
alternate code paths if unavailable.
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Tested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200521014341.29095-2-alistair@popple.id.au
Since the previous commit that saves the value of FSCR configured at
boot into init_task.thread.fscr, the static initialisation in
INIT_THREAD now no longer has any effect.
So remove it.
For non DT CPU features, the end result is the same, because
__init_FSCR() is called on all CPUs that have an FSCR (Power8,
Power9), and it sets FSCR_TAR & FSCR_EBB.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200527145843.2761782-4-mpe@ellerman.id.au
At boot the FSCR is initialised via one of two paths. On most systems
it's set to a hard coded value in __init_FSCR().
On newer skiboot systems we use the device tree CPU features binding,
where firmware can tell Linux what bits to set in FSCR (and HFSCR).
In both cases the value that's configured at boot is not propagated
into the init_task.thread.fscr value prior to the initial fork of init
(pid 1), which means the value is not used by any processes other than
swapper (the idle task).
For the __init_FSCR() case this is OK, because the value in
init_task.thread.fscr is initialised to something sensible. However it
does mean that the value set in __init_FSCR() is not used other than
for swapper, which is odd and confusing.
The bigger problem is for the device tree CPU features case it
prevents firmware from setting (or clearing) FSCR bits for use by user
space. This means all existing kernels can not have features
enabled/disabled by firmware if those features require
setting/clearing FSCR bits.
We can handle both cases by saving the FSCR value into
init_task.thread.fscr after we have initialised it at boot. This fixes
the bug for device tree CPU features, and will allow us to simplify
the initialisation for the __init_FSCR() case in a future patch.
Fixes: 5a61ef74f2 ("powerpc/64s: Support new device tree binding for discovering CPU features")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200527145843.2761782-3-mpe@ellerman.id.au
The device tree CPU features binding includes FSCR bit numbers which
Linux is instructed to set by firmware.
Whether that's a good idea or not, in the case of the DSCR the Linux
implementation has a hard requirement that the FSCR_DSCR bit not be
set by default. We use it to track when a process reads/writes to
DSCR, so it must be clear to begin with.
So if firmware tells us to set FSCR_DSCR we must ignore it.
Currently this does not cause a bug in our DSCR handling because the
value of FSCR that the device tree CPU features code establishes is
only used by swapper. All other tasks use the value hard coded in
init_task.thread.fscr.
However we'd like to fix that in a future commit, at which point this
will become necessary.
Fixes: 5a61ef74f2 ("powerpc/64s: Support new device tree binding for discovering CPU features")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200527145843.2761782-2-mpe@ellerman.id.au
__init_FSCR() was added originally in commit 2468dcf641 ("powerpc:
Add support for context switching the TAR register") (Feb 2013), and
only set FSCR_TAR.
At that point FSCR (Facility Status and Control Register) was not
context switched, so the setting was permanent after boot.
Later we added initialisation of FSCR_DSCR to __init_FSCR(), in commit
54c9b2253d ("powerpc: Set DSCR bit in FSCR setup") (Mar 2013), again
that was permanent after boot.
Then commit 2517617e0d ("powerpc: Fix context switch DSCR on
POWER8") (Aug 2013) added a limited context switch of FSCR, just the
FSCR_DSCR bit was context switched based on thread.dscr_inherit. That
commit said "This clears the H/FSCR DSCR bit initially", but it
didn't, it left the initialisation of FSCR_DSCR in __init_FSCR().
However the initial context switch from init_task to pid 1 would clear
FSCR_DSCR because thread.dscr_inherit was 0.
That commit also introduced the requirement that FSCR_DSCR be clear
for user processes, so that we can take the facility unavailable
interrupt in order to manage dscr_inherit.
Then in commit 152d523e63 ("powerpc: Create context switch helpers
save_sprs() and restore_sprs()") (Dec 2015) FSCR was added to
thread_struct. However it still wasn't fully context switched, we just
took the existing value and set FSCR_DSCR if the new thread had
dscr_inherit set. FSCR was still initialised at boot to FSCR_DSCR |
FSCR_TAR, but that value was not propagated into the thread_struct, so
the initial context switch set FSCR_DSCR back to 0.
Finally commit b57bd2de8c ("powerpc: Improve FSCR init and context
switching") (Jun 2016) added a full context switch of the FSCR, and
added an initialisation of init_task.thread.fscr to FSCR_TAR |
FSCR_EBB, but omitted FSCR_DSCR.
The end result is that swapper runs with FSCR_DSCR set because of the
initialisation in __init_FSCR(), but no other processes do, they use
the value from init_task.thread.fscr.
Having FSCR_DSCR set for swapper allows it to access SPR 3 from
userspace, but swapper never runs userspace, so it has no useful
effect. It's also confusing to have the value initialised in two
places to two different values.
So remove FSCR_DSCR from __init_FSCR(), this at least gets us to the
point where there's a single value of FSCR, even if it's still set in
two places.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Alistair Popple <alistair@popple.id.au>
Link: https://lore.kernel.org/r/20200527145843.2761782-1-mpe@ellerman.id.au
Since commit c55d7b5e64 ("powerpc: Remove STRICT_KERNEL_RWX
incompatibility with RELOCATABLE"), powerpc kernels with
-mprofile-kernel can crash in certain scenarios with a trace like below:
BUG: Unable to handle kernel instruction fetch (NULL pointer?)
Faulting instruction address: 0x00000000
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=256 DEBUG_PAGEALLOC NUMA PowerNV
<snip>
NIP [0000000000000000] 0x0
LR [c0080000102c0048] ext4_iomap_end+0x8/0x30 [ext4]
Call Trace:
iomap_apply+0x20c/0x920 (unreliable)
iomap_bmap+0xfc/0x160
ext4_bmap+0xa4/0x180 [ext4]
bmap+0x4c/0x80
jbd2_journal_init_inode+0x44/0x1a0 [jbd2]
ext4_load_journal+0x440/0x860 [ext4]
ext4_fill_super+0x342c/0x3ab0 [ext4]
mount_bdev+0x25c/0x290
ext4_mount+0x28/0x50 [ext4]
legacy_get_tree+0x4c/0xb0
vfs_get_tree+0x4c/0x130
do_mount+0xa18/0xc50
sys_mount+0x158/0x180
system_call+0x5c/0x68
The NIP points to NULL, or a random location (data even), while the LR
always points to the LEP of a function (with an offset of 8), indicating
that something went wrong with ftrace. However, ftrace is not
necessarily active when such crashes occur.
The kernel OOPS sometimes follows a warning from ftrace indicating that
some module functions could not be patched with a nop. Other times, if a
module is loaded early during boot, instruction patching can fail due to
a separate bug, but the error is not reported due to missing error
reporting.
In all the above cases when instruction patching fails, ftrace will be
disabled but certain kernel module functions will be left with default
calls to _mcount(). This is not a problem with ELFv1. However, with
-mprofile-kernel, the default stub is problematic since it depends on a
valid module TOC in r2. If the kernel (or a different module) calls into
a function that does not use the TOC, the function won't have a prologue
to setup the module TOC. When that function calls into _mcount(), we
will end up in the relocation stub that will use the previous TOC, and
end up trying to jump into a random location. From the above trace:
iomap_apply+0x20c/0x920 [kernel TOC]
|
V
ext4_iomap_end+0x8/0x30 [no GEP == kernel TOC]
|
V
_mcount() stub
[uses kernel TOC -> random entry]
To address this, let's change over to using the special stub that is
used for ftrace_[regs_]caller() for _mcount(). This ensures that we are
not dependent on a valid module TOC in r2 for default _mcount()
handling.
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Tested-by: Qian Cai <cai@lca.pw>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8affd4298d22099bbd82544fab8185700a6222b1.1587488954.git.naveen.n.rao@linux.vnet.ibm.com
For -mprofile-kernel, we need special handling when generating stubs for
ftrace calls such as _mcount(). To faciliate this, we check if a
R_PPC64_REL24 relocation is for a symbol named "_mcount()" along with
also checking the instruction sequence. The latter is not really
required since "_mcount()" is an exported symbol and kernel modules
cannot use it. As such, drop the additional checking and simplify the
code. This helps unify stub creation for ftrace stubs with
-mprofile-kernel and aids in code reuse.
Also rename is_mprofile_mcount_callsite() to is_mprofile_ftrace_call()
to reflect the checking being done.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7d9c316adfa1fb787ad268bb4691e7e4059ff2d5.1587488954.git.naveen.n.rao@linux.vnet.ibm.com
Mapping of early shadow area is implemented by using a single static
page table having all entries pointing to the same early shadow page.
The shadow area must therefore occupy full PGD entries.
The shadow area has a size of 128MB starting at 0xf8000000.
With 4k pages, a PGD entry is 4MB
With 16k pages, a PGD entry is 64MB
With 64k pages, a PGD entry is 1GB which is too big.
Until we rework the early shadow mapping, disable KASAN when the page
size is too big.
Fixes: 2edb16efc8 ("powerpc/32: Add KASAN support")
Cc: stable@vger.kernel.org # v5.2+
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7195fcde7314ccbf7a081b356084a69d421b10d4.1590660977.git.christophe.leroy@csgroup.eu
On book3s/32, KUAP is an heavy process as it requires to
determine which segments are impacted and unlock/lock
each of them.
And since the implementation of user_access_begin/end, it
is even worth for the time being because unlike __get_user(),
user_access_begin doesn't make difference between read and write
and unlocks access also for read allthought that's unneeded
on book3s/32.
As shown by the size of a kernel built with KUAP and one without,
the overhead is 64k bytes of code. As a comparison a similar
build on an 8xx has an overhead of only 8k bytes of code.
text data bss dec hex filename
7230416 1425868 837376 9493660 90dc9c vmlinux.kuap6xx
7165012 1425548 837376 9427936 8fdbe0 vmlinux.nokuap6xx
6519796 1960028 477464 8957288 88ad68 vmlinux.kuap8xx
6511664 1959864 477464 8948992 888d00 vmlinux.nokuap8xx
Until a more optimised KUAP is implemented on book3s/32,
don't select it by default.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/154a99399317b096ac1f04827b9f8d7a9179ddc1.1586962586.git.christophe.leroy@c-s.fr
To enable/disable kernel access to user space, the 8xx has to
modify the properties of access group 1. This is done by writing
predefined values into SPRN_Mx_AP registers.
As of today, a __put_user() gives:
00000d64 <my_test>:
d64: 3d 20 4f ff lis r9,20479
d68: 61 29 ff ff ori r9,r9,65535
d6c: 7d 3a c3 a6 mtspr 794,r9
d70: 39 20 00 00 li r9,0
d74: 90 83 00 00 stw r4,0(r3)
d78: 3d 20 6f ff lis r9,28671
d7c: 61 29 ff ff ori r9,r9,65535
d80: 7d 3a c3 a6 mtspr 794,r9
d84: 4e 80 00 20 blr
Because only groups 0 and 1 are used, the definition of
groups 2 to 15 doesn't matter.
By setting unused bits to 0 instead on 1, one instruction is
removed for each lock and unlock action:
00000d5c <my_test>:
d5c: 3d 20 40 00 lis r9,16384
d60: 7d 3a c3 a6 mtspr 794,r9
d64: 39 20 00 00 li r9,0
d68: 90 83 00 00 stw r4,0(r3)
d6c: 3d 20 60 00 lis r9,24576
d70: 7d 3a c3 a6 mtspr 794,r9
d74: 4e 80 00 20 blr
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/57425c33dd72f292b1a23570244b81419072a7aa.1586945153.git.christophe.leroy@c-s.fr
Implement rtas_call_reentrant() for reentrant rtas-calls:
"ibm,int-on", "ibm,int-off",ibm,get-xive" and "ibm,set-xive".
On LoPAPR Version 1.1 (March 24, 2016), from 7.3.10.1 to 7.3.10.4,
items 2 and 3 say:
2 - For the PowerPC External Interrupt option: The * call must be
reentrant to the number of processors on the platform.
3 - For the PowerPC External Interrupt option: The * argument call
buffer for each simultaneous call must be physically unique.
So, these rtas-calls can be called in a lockless way, if using
a different buffer for each cpu doing such rtas call.
For this, it was suggested to add the buffer (struct rtas_args)
in the PACA struct, so each cpu can have it's own buffer.
The PACA struct received a pointer to rtas buffer, which is
allocated in the memory range available to rtas 32-bit.
Reentrant rtas calls are useful to avoid deadlocks in crashing,
where rtas-calls are needed, but some other thread crashed holding
the rtas.lock.
This is a backtrace of a deadlock from a kdump testing environment:
#0 arch_spin_lock
#1 lock_rtas ()
#2 rtas_call (token=8204, nargs=1, nret=1, outputs=0x0)
#3 ics_rtas_mask_real_irq (hw_irq=4100)
#4 machine_kexec_mask_interrupts
#5 default_machine_crash_shutdown
#6 machine_crash_shutdown
#7 __crash_kexec
#8 crash_kexec
#9 oops_end
Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
[mpe: Move under #ifdef PSERIES to avoid build breakage]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200518234245.200672-3-leobras.c@gmail.com
In order to get any rtas* struct into other headers, including rtas.h
may cause a lot of errors, regarding include dependency needed for
inline functions.
Create rtas-types.h and move there all type/struct definitions
from rtas.h, then include rtas-types.h into rtas.h.
Also, as suggested by checkpath.pl, replace uint8_t for u8.
Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200518234245.200672-2-leobras.c@gmail.com
Currently, if printk lock (logbuf_lock) is held by other thread during
crash, there is a chance of deadlocking the crash on next printk, and
blocking a possibly desired kdump.
At the start of default_machine_crash_shutdown, make printk enter
NMI context, as it will use per-cpu buffers to store the message,
and avoid locking logbuf_lock.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200512214533.93878-1-leobras.c@gmail.com
While providing guests, it's desirable to resize it's memory on demand.
By now, it's possible to do so by creating a guest with a small base
memory, hot-plugging all the rest, and using 'movable_node' kernel
command-line parameter, which puts all hot-plugged memory in
ZONE_MOVABLE, allowing it to be removed whenever needed.
But there is an issue regarding guest reboot:
If memory is hot-plugged, and then the guest is rebooted, all hot-plugged
memory goes to ZONE_NORMAL, which offers no guaranteed hot-removal.
It usually prevents this memory to be hot-removed from the guest.
It's possible to use device-tree information to fix that behavior, as
it stores flags for LMB ranges on ibm,dynamic-memory-vN.
It involves marking each memblock with the correct flags as hotpluggable
memory, which mm/memblock.c puts in ZONE_MOVABLE during boot if
'movable_node' is passed.
For carrying such information, the new flag DRCONF_MEM_HOTREMOVABLE was
proposed and accepted into Power Architecture documentation.
This flag should be:
- true (b=1) if the hypervisor may want to hot-remove it later, and
- false (b=0) if it does not care.
During boot, guest kernel reads the device-tree, early_init_drmem_lmb()
is called for every added LMBs. Here, checking for this new flag and
marking memblocks as hotplugable memory is enough to get the desirable
behavior.
This should cause no change if 'movable_node' parameter is not passed
in kernel command-line.
Signed-off-by: Leonardo Bras <leonardo@linux.ibm.com>
Reviewed-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200402195156.626430-1-leonardo@linux.ibm.com
This adds the CPU or thread number to printk messages. This helps a
lot when deciphering concurrent oopses that have been interleaved.
Example output, of PID1 (T1) triggering a warning:
[ 1.581678][ T1] WARNING: CPU: 0 PID: 1 at crypto/rsa-pkcs1pad.c:539 pkcs1pad_verify+0x38/0x140
[ 1.581681][ T1] Modules linked in:
[ 1.581693][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.5.0-rc5-gcc-8.2.0-00121-gf84c2e595927-dirty #1515
[ 1.581700][ T1] NIP: c000000000207d64 LR: c000000000207d3c CTR: c000000000207d2c
[ 1.581708][ T1] REGS: c0000000fd2e7560 TRAP: 0700 Not tainted (5.5.0-rc5-gcc-8.2.0-00121-gf84c2e595927-dirty)
[ 1.581712][ T1] MSR: 9000000000029033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 44000222 XER: 00040000
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200520121257.961112-1-mpe@ellerman.id.au
Currently when we boot on a big core system, we get this print:
[ 0.040500] Using small cores at SMT level
This is misleading as we've actually detected big cores.
This patch clears up the print to say we've detect big cores but are
using small cores for scheduling.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200528230731.1235752-1-mikey@neuling.org
'mem=" option is an easy way to put high pressure on memory during
some test. Hence after applying the memory limit, instead of total
mem, the actual usable memory should be considered when reserving mem
for crashkernel. Otherwise the boot up may experience OOM issue.
E.g. it would reserve 4G prior to the change and 512M afterward, if
passing
crashkernel="2G-4G:384M,4G-16G:512M,16G-64G:1G,64G-128G:2G,128G-:4G",
and mem=5G on a 256G machine.
This issue is powerpc specific because it puts higher priority on
fadump and kdump reservation than on "mem=". Referring the following
code:
if (fadump_reserve_mem() == 0)
reserve_crashkernel();
...
/* Ensure that total memory size is page-aligned. */
limit = ALIGN(memory_limit ?: memblock_phys_mem_size(), PAGE_SIZE);
memblock_enforce_memory_limit(limit);
While on other arches, the effect of "mem=" takes a higher priority
and pass through memblock_phys_mem_size() before calling
reserve_crashkernel().
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1585749644-4148-1-git-send-email-kernelfans@gmail.com
kbuild test robot reported some build warnings in the hw_breakpoint
code when compiled with clang[1]. Some of them were introduced by the
recent powerpc change to add arch_reserve_bp_slot() and
arch_release_bp_slot(). Fix them all.
kernel/events/hw_breakpoint.c:71:12: warning: no previous prototype for function 'hw_breakpoint_weight'
kernel/events/hw_breakpoint.c:216:12: warning: no previous prototype for function 'arch_reserve_bp_slot'
kernel/events/hw_breakpoint.c:221:13: warning: no previous prototype for function 'arch_release_bp_slot'
kernel/events/hw_breakpoint.c:228:13: warning: no previous prototype for function 'arch_unregister_hw_breakpoint'
[1]: https://lore.kernel.org/linuxppc-dev/202005192233.oi9CjRtA%25lkp@intel.com/
Fixes: 29da4f91c0 ("powerpc/watchpoint: Don't allow concurrent perf and ptrace events")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
[mpe: Drop extern, flesh out change log, add Fixes tag]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200602041208.128913-1-ravi.bangoria@linux.ibm.com
Pull vfs updates from Al Viro:
"Assorted patches from Miklos.
An interesting part here is /proc/mounts stuff..."
The "/proc/mounts stuff" is using a cursor for keeeping the location
data while traversing the mount listing.
Also probably worth noting is the addition of faccessat2(), which takes
an additional set of flags to specify how the lookup is done
(AT_EACCESS, AT_SYMLINK_NOFOLLOW, AT_EMPTY_PATH).
* 'from-miklos' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: add faccessat2 syscall
vfs: don't parse "silent" option
vfs: don't parse "posixacl" option
vfs: don't parse forbidden flags
statx: add mount_root
statx: add mount ID
statx: don't clear STATX_ATIME on SB_RDONLY
uapi: deprecate STATX_ALL
utimensat: AT_EMPTY_PATH support
vfs: split out access_override_creds()
proc/mounts: add cursor
aio: fix async fsync creds
vfs: allow unprivileged whiteout creation
Pull uaccess/coredump updates from Al Viro:
"set_fs() removal in coredump-related area - mostly Christoph's
stuff..."
* 'work.set_fs-exec' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
binfmt_elf_fdpic: remove the set_fs(KERNEL_DS) in elf_fdpic_core_dump
binfmt_elf: remove the set_fs(KERNEL_DS) in elf_core_dump
binfmt_elf: remove the set_fs in fill_siginfo_note
signal: refactor copy_siginfo_to_user32
powerpc/spufs: simplify spufs core dumping
powerpc/spufs: stop using access_ok
powerpc/spufs: fix copy_to_user while atomic
Pull uaccess/csum updates from Al Viro:
"Regularize the sitation with uaccess checksum primitives:
- fold csum_partial_... into csum_and_copy_..._user()
- on x86 collapse several access_ok()/stac()/clac() into
user_access_begin()/user_access_end()"
* 'uaccess.csum' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
default csum_and_copy_to_user(): don't bother with access_ok()
take the dummy csum_and_copy_from_user() into net/checksum.h
arm: switch to csum_and_copy_from_user()
sh32: convert to csum_and_copy_from_user()
m68k: convert to csum_and_copy_from_user()
xtensa: switch to providing csum_and_copy_from_user()
sparc: switch to providing csum_and_copy_from_user()
parisc: turn csum_partial_copy_from_user() into csum_and_copy_from_user()
alpha: turn csum_partial_copy_from_user() into csum_and_copy_from_user()
ia64: turn csum_partial_copy_from_user() into csum_and_copy_from_user()
ia64: csum_partial_copy_nocheck(): don't abuse csum_partial_copy_from_user()
x86: switch 32bit csum_and_copy_to_user() to user_access_{begin,end}()
x86: switch both 32bit and 64bit to providing csum_and_copy_from_user()
x86_64: csum_..._copy_..._user(): switch to unsafe_..._user()
get rid of csum_partial_copy_to_user()
Pull documentation updates from Jonathan Corbet:
"A fair amount of stuff this time around, dominated by yet another
massive set from Mauro toward the completion of the RST conversion. I
*really* hope we are getting close to the end of this. Meanwhile,
those patches reach pretty far afield to update document references
around the tree; there should be no actual code changes there. There
will be, alas, more of the usual trivial merge conflicts.
Beyond that we have more translations, improvements to the sphinx
scripting, a number of additions to the sysctl documentation, and lots
of fixes"
* tag 'docs-5.8' of git://git.lwn.net/linux: (130 commits)
Documentation: fixes to the maintainer-entry-profile template
zswap: docs/vm: Fix typo accept_threshold_percent in zswap.rst
tracing: Fix events.rst section numbering
docs: acpi: fix old http link and improve document format
docs: filesystems: add info about efivars content
Documentation: LSM: Correct the basic LSM description
mailmap: change email for Ricardo Ribalda
docs: sysctl/kernel: document unaligned controls
Documentation: admin-guide: update bug-hunting.rst
docs: sysctl/kernel: document ngroups_max
nvdimm: fixes to maintainter-entry-profile
Documentation/features: Correct RISC-V kprobes support entry
Documentation/features: Refresh the arch support status files
Revert "docs: sysctl/kernel: document ngroups_max"
docs: move locking-specific documents to locking/
docs: move digsig docs to the security book
docs: move the kref doc into the core-api book
docs: add IRQ documentation at the core-api book
docs: debugging-via-ohci1394.txt: add it to the core-api book
docs: fix references for ipmi.rst file
...
Pull ARM updates from Russell King:
- remove a now unnecessary usage of the KERNEL_DS for
sys_oabi_epoll_ctl()
- update my email address in a number of drivers
- decompressor EFI updates from Ard Biesheuvel
- module unwind section handling updates
- sparsemem Kconfig cleanups
- make act_mm macro respect THREAD_SIZE
* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
ARM: 8980/1: Allow either FLATMEM or SPARSEMEM on the multiplatform build
ARM: 8979/1: Remove redundant ARCH_SPARSEMEM_DEFAULT setting
ARM: 8978/1: mm: make act_mm() respect THREAD_SIZE
ARM: decompressor: run decompressor in place if loaded via UEFI
ARM: decompressor: move GOT into .data for EFI enabled builds
ARM: decompressor: defer loading of the contents of the LC0 structure
ARM: decompressor: split off _edata and stack base into separate object
ARM: decompressor: move headroom variable out of LC0
ARM: 8976/1: module: allow arch overrides for .init section names
ARM: 8975/1: module: fix handling of unwind init sections
ARM: 8974/1: use SPARSMEM_STATIC when SPARSEMEM is enabled
ARM: 8971/1: replace the sole use of a symbol with its definition
ARM: 8969/1: decompressor: simplify libfdt builds
Update rmk's email address in various drivers
ARM: compat: remove KERNEL_DS usage in sys_oabi_epoll_ctl()
Pull arm64 updates from Will Deacon:
"A sizeable pile of arm64 updates for 5.8.
Summary below, but the big two features are support for Branch Target
Identification and Clang's Shadow Call stack. The latter is currently
arm64-only, but the high-level parts are all in core code so it could
easily be adopted by other architectures pending toolchain support
Branch Target Identification (BTI):
- Support for ARMv8.5-BTI in both user- and kernel-space. This allows
branch targets to limit the types of branch from which they can be
called and additionally prevents branching to arbitrary code,
although kernel support requires a very recent toolchain.
- Function annotation via SYM_FUNC_START() so that assembly functions
are wrapped with the relevant "landing pad" instructions.
- BPF and vDSO updates to use the new instructions.
- Addition of a new HWCAP and exposure of BTI capability to userspace
via ID register emulation, along with ELF loader support for the
BTI feature in .note.gnu.property.
- Non-critical fixes to CFI unwind annotations in the sigreturn
trampoline.
Shadow Call Stack (SCS):
- Support for Clang's Shadow Call Stack feature, which reserves
platform register x18 to point at a separate stack for each task
that holds only return addresses. This protects function return
control flow from buffer overruns on the main stack.
- Save/restore of x18 across problematic boundaries (user-mode,
hypervisor, EFI, suspend, etc).
- Core support for SCS, should other architectures want to use it
too.
- SCS overflow checking on context-switch as part of the existing
stack limit check if CONFIG_SCHED_STACK_END_CHECK=y.
CPU feature detection:
- Removed numerous "SANITY CHECK" errors when running on a system
with mismatched AArch32 support at EL1. This is primarily a concern
for KVM, which disabled support for 32-bit guests on such a system.
- Addition of new ID registers and fields as the architecture has
been extended.
Perf and PMU drivers:
- Minor fixes and cleanups to system PMU drivers.
Hardware errata:
- Unify KVM workarounds for VHE and nVHE configurations.
- Sort vendor errata entries in Kconfig.
Secure Monitor Call Calling Convention (SMCCC):
- Update to the latest specification from Arm (v1.2).
- Allow PSCI code to query the SMCCC version.
Software Delegated Exception Interface (SDEI):
- Unexport a bunch of unused symbols.
- Minor fixes to handling of firmware data.
Pointer authentication:
- Add support for dumping the kernel PAC mask in vmcoreinfo so that
the stack can be unwound by tools such as kdump.
- Simplification of key initialisation during CPU bringup.
BPF backend:
- Improve immediate generation for logical and add/sub instructions.
vDSO:
- Minor fixes to the linker flags for consistency with other
architectures and support for LLVM's unwinder.
- Clean up logic to initialise and map the vDSO into userspace.
ACPI:
- Work around for an ambiguity in the IORT specification relating to
the "num_ids" field.
- Support _DMA method for all named components rather than only PCIe
root complexes.
- Minor other IORT-related fixes.
Miscellaneous:
- Initialise debug traps early for KGDB and fix KDB cacheflushing
deadlock.
- Minor tweaks to early boot state (documentation update, set
TEXT_OFFSET to 0x0, increase alignment of PE/COFF sections).
- Refactoring and cleanup"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (148 commits)
KVM: arm64: Move __load_guest_stage2 to kvm_mmu.h
KVM: arm64: Check advertised Stage-2 page size capability
arm64/cpufeature: Add get_arm64_ftr_reg_nowarn()
ACPI/IORT: Remove the unused __get_pci_rid()
arm64/cpuinfo: Add ID_MMFR4_EL1 into the cpuinfo_arm64 context
arm64/cpufeature: Add remaining feature bits in ID_AA64PFR1 register
arm64/cpufeature: Add remaining feature bits in ID_AA64PFR0 register
arm64/cpufeature: Add remaining feature bits in ID_AA64ISAR0 register
arm64/cpufeature: Add remaining feature bits in ID_MMFR4 register
arm64/cpufeature: Add remaining feature bits in ID_PFR0 register
arm64/cpufeature: Introduce ID_MMFR5 CPU register
arm64/cpufeature: Introduce ID_DFR1 CPU register
arm64/cpufeature: Introduce ID_PFR2 CPU register
arm64/cpufeature: Make doublelock a signed feature in ID_AA64DFR0
arm64/cpufeature: Drop TraceFilt feature exposure from ID_DFR0 register
arm64/cpufeature: Add explicit ftr_id_isar0[] for ID_ISAR0 register
arm64: mm: Add asid_gen_match() helper
firmware: smccc: Fix missing prototype warning for arm_smccc_version_init
arm64: vdso: Fix CFI directives in sigreturn trampoline
arm64: vdso: Don't prefix sigreturn trampoline with a BTI C instruction
...
Pull m68k updates from Geert Uytterhoeven:
- several Mac fixes
- defconfig updates
- minor cleanups and fixes
* tag 'm68k-for-v5.8-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
m68k: tools: Replace zero-length array with flexible-array member
m68k: Add missing __user annotation in get_user()
m68k: mac: Avoid stuck ISM IOP interrupt on Quadra 900/950
m68k: mac: Remove misleading comment
m68k: mac: Don't call via_flush_cache() on Mac IIfx
m68k: defconfig: Update defconfigs for v5.7-rc1
m68k: amiga: config: Replace zero-length array with flexible-array member
m68k: amiga: config: Mark expected switch fall-through
Pull x86 vdso updates from Ingo Molnar:
"Clean up various aspects of the vDSO code, no change in functionality
intended"
* tag 'x86-vdso-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/vdso/Makefile: Add vobjs32
x86/vdso/vdso2c: Convert iterators to unsigned
x86/vdso/vdso2c: Correct error messages on file open
Pull x86 platform updates from Ingo Molnar:
"This tree cleans up various aspects of the UV platform support code,
it removes unnecessary functions and cleans up the rest"
* tag 'x86-platform-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apic/uv: Remove code for unused distributed GRU mode
x86/platform/uv: Remove the unused _uv_cpu_blade_processor_id() macro
x86/platform/uv: Unexport uv_apicid_hibits
x86/platform/uv: Remove _uv_hub_info_check()
x86/platform/uv: Simplify uv_send_IPI_one()
x86/platform/uv: Mark uv_min_hub_revision_id static
x86/platform/uv: Mark is_uv_hubless() static
x86/platform/uv: Remove the UV*_HUB_IS_SUPPORTED macros
x86/platform/uv: Unexport symbols only used by x2apic_uv_x.c
x86/platform/uv: Unexport sn_coherency_id
x86/platform/uv: Remove the uv_partition_coherence_id() macro
x86/platform/uv: Mark uv_bios_call() and uv_bios_call_irqsave() static
Pull x86 FPU updates from Ingo Molnar:
"Most of the changes here related to 'XSAVES supervisor state' support,
which is a feature that allows kernel-only data to be automatically
saved/restored by the FPU context switching code.
CPU features that can be supported this way are Intel PT, 'PASID' and
CET features"
* tag 'x86-fpu-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu/xstate: Restore supervisor states for signal return
x86/fpu/xstate: Preserve supervisor states for the slow path in __fpu__restore_sig()
x86/fpu: Introduce copy_supervisor_to_kernel()
x86/fpu/xstate: Update copy_kernel_to_xregs_err() for supervisor states
x86/fpu/xstate: Update sanitize_restored_xstate() for supervisor xstates
x86/fpu/xstate: Define new functions for clearing fpregs and xstates
x86/fpu/xstate: Introduce XSAVES supervisor states
x86/fpu/xstate: Separate user and supervisor xfeatures mask
x86/fpu/xstate: Define new macros for supervisor and user xstates
x86/fpu/xstate: Rename validate_xstate_header() to validate_user_xstate_header()
