While running regressions, observed below kernel panic when sdio disconnect
called. This is because of, kthread_stop() is taking care of
wait_for_completion() by default. When wait_for_completion triggered
in kthread_stop and as it was done already, giving kernel panic.
Hence, removing redundant wait_for_completion() from rsi_kill_thread().
In the corner case where the gpio driver probe fails, for whatever
reason, the suspend and resume handlers will still be called as they
have to be registered as syscore operations. This applies as well when
no probe was called while the driver has been built in the kernel.
Nicolas tracked this in :
https://bugzilla.kernel.org/show_bug.cgi?id=200905
Therefore, add a failsafe in these function, and test if a proper probe
succeeded and the driver is functional.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Reported-by: Nicolas Chauvet <kwizart@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The ext4 fstrim implementation uses the block bitmaps to find free space
that can be discarded. If we haven't replayed the journal, the bitmaps
will be stale and we absolutely *cannot* use stale metadata to zap the
underlying storage.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Sasha Levin <sashal@kernel.org>
It was mapped to EIO which can be confusing when user space
queries for an object GUID for an object for which the server
file system doesn't support (or hasn't saved one).
As Amir Goldstein suggested this is similar to ENOATTR
(equivalently ENODATA in Linux errno definitions) so
changing NT STATUS code mapping for OBJECTID_NOT_FOUND
to ENODATA.
Signed-off-by: Steve French <stfrench@microsoft.com> CC: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
When building with -Wsometimes-uninitialized, Clang warns:
arch/x86/kernel/hw_breakpoint.c:355:2: warning: variable 'align' is used
uninitialized whenever switch default is taken
[-Wsometimes-uninitialized]
The default cannot be reached because arch_build_bp_info() initializes
hw->len to one of the specified cases. Nevertheless the warning is valid
and returning -EINVAL makes sure that this cannot be broken by future
modifications.
Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: clang-built-linux@googlegroups.com Link: https://github.com/ClangBuiltLinux/linux/issues/392 Link: https://lkml.kernel.org/r/20190307212756.4648-1-natechancellor@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
The spec states in 10.4.16 that the Protected Memory Enable
Register should be treated as read-only for implementations
not supporting protected memory regions (PLMR and PHMR fields
reported as Clear in the Capability register).
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: mark gross <mgross@intel.com> Suggested-by: Ashok Raj <ashok.raj@intel.com> Fixes: f8bab73515ca5 ("intel-iommu: PMEN support") Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
This is because it expands the macro into a non-functioning calling
sequence. The calling order must be:
outb(CX86_CCR2, 0x22);
inb(0x23);
From the comments:
* When using the old macros a line like
* setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88);
* gets expanded to:
* do {
* outb((CX86_CCR2), 0x22);
* outb((({
* outb((CX86_CCR2), 0x22);
* inb(0x23);
* }) | 0x88), 0x23);
* } while (0);
The new macros fix this problem, so use them instead. Tested on an
actual Geode processor.
mbigen_write_msg clears eventid bits of a mbigen register
when free a interrupt, because msi_domain_deactivate memset
struct msg to zero. Then multiple mbigen pins with zero eventid
will report the same interrupt number.
Direct leak of 1160 byte(s) in 1 object(s) allocated from:
#0 0x7f1b6fc84138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
#1 0x55bd50005599 in zalloc util/util.h:23
#2 0x55bd500068f5 in perf_evsel__newtp_idx util/evsel.c:327
#3 0x55bd4ff810fc in perf_evsel__newtp /home/work/linux/tools/perf/util/evsel.h:216
#4 0x55bd4ff81608 in test__perf_evsel__tp_sched_test tests/evsel-tp-sched.c:69
#5 0x55bd4ff528e6 in run_test tests/builtin-test.c:358
#6 0x55bd4ff52baf in test_and_print tests/builtin-test.c:388
#7 0x55bd4ff543fe in __cmd_test tests/builtin-test.c:583
#8 0x55bd4ff5572f in cmd_test tests/builtin-test.c:722
#9 0x55bd4ffc4087 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
#10 0x55bd4ffc45c6 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
#11 0x55bd4ffc49ca in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
#12 0x55bd4ffc5138 in main /home/changbin/work/linux/tools/perf/perf.c:520
#13 0x7f1b6e34809a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)
Indirect leak of 19 byte(s) in 1 object(s) allocated from:
#0 0x7f1b6fc83f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
#1 0x7f1b6e3ac30f in vasprintf (/lib/x86_64-linux-gnu/libc.so.6+0x8830f)
Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Fixes: 6a6cd11d4e57 ("perf test: Add test for the sched tracepoint format fields") Link: http://lkml.kernel.org/r/20190316080556.3075-17-changbin.du@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Direct leak of 40 byte(s) in 1 object(s) allocated from:
#0 0x7f0333a88f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
#1 0x5625e5326213 in cpu_map__trim_new util/cpumap.c:45
#2 0x5625e5326703 in cpu_map__read util/cpumap.c:103
#3 0x5625e53267ef in cpu_map__read_all_cpu_map util/cpumap.c:120
#4 0x5625e5326915 in cpu_map__new util/cpumap.c:135
#5 0x5625e517b355 in test__openat_syscall_event_on_all_cpus tests/openat-syscall-all-cpus.c:36
#6 0x5625e51528e6 in run_test tests/builtin-test.c:358
#7 0x5625e5152baf in test_and_print tests/builtin-test.c:388
#8 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
#9 0x5625e515572f in cmd_test tests/builtin-test.c:722
#10 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
#11 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
#12 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
#13 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
#14 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)
Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Fixes: f30a79b012e5 ("perf tools: Add reference counting for cpu_map object") Link: http://lkml.kernel.org/r/20190316080556.3075-15-changbin.du@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Direct leak of 48 byte(s) in 1 object(s) allocated from:
#0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
#1 0x5625e5330a5e in zalloc util/util.h:23
#2 0x5625e5330a9b in perf_counts__new util/counts.c:10
#3 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
#4 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
#5 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
#6 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
#7 0x5625e51528e6 in run_test tests/builtin-test.c:358
#8 0x5625e5152baf in test_and_print tests/builtin-test.c:388
#9 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
#10 0x5625e515572f in cmd_test tests/builtin-test.c:722
#11 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
#12 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
#13 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
#14 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
#15 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)
Indirect leak of 72 byte(s) in 1 object(s) allocated from:
#0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
#1 0x5625e532560d in zalloc util/util.h:23
#2 0x5625e532566b in xyarray__new util/xyarray.c:10
#3 0x5625e5330aba in perf_counts__new util/counts.c:15
#4 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
#5 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
#6 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
#7 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
#8 0x5625e51528e6 in run_test tests/builtin-test.c:358
#9 0x5625e5152baf in test_and_print tests/builtin-test.c:388
#10 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
#11 0x5625e515572f in cmd_test tests/builtin-test.c:722
#12 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
#13 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
#14 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
#15 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
#16 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)
His patch took care of evsel->prev_raw_counts, but the above backtraces
are about evsel->counts, so fix that instead.
Reported-by: Changbin Du <changbin.du@gmail.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lkml.kernel.org/n/tip-hd1x13g59f0nuhe4anxhsmfp@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Direct leak of 4356 byte(s) in 120 object(s) allocated from:
#0 0x7ff1a2b5a070 in __interceptor_strdup (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x3b070)
#1 0x55719aef4814 in build_id_cache__origname util/build-id.c:215
#2 0x55719af649b6 in print_sdt_events util/parse-events.c:2339
#3 0x55719af66272 in print_events util/parse-events.c:2542
#4 0x55719ad1ecaa in cmd_list /home/changbin/work/linux/tools/perf/builtin-list.c:58
#5 0x55719aec745d in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
#6 0x55719aec7d1a in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
#7 0x55719aec8184 in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
#8 0x55719aeca41a in main /home/changbin/work/linux/tools/perf/perf.c:520
#9 0x7ff1a07ae09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)
Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Fixes: 40218daea1db ("perf list: Show SDT and pre-cached events") Link: http://lkml.kernel.org/r/20190316080556.3075-7-changbin.du@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Direct leak of 66 byte(s) in 5 object(s) allocated from:
#0 0x7ff3b1f32070 in __interceptor_strdup (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x3b070)
#1 0x560c8761034d in collect_config util/config.c:597
#2 0x560c8760d9cb in get_value util/config.c:169
#3 0x560c8760dfd7 in perf_parse_file util/config.c:285
#4 0x560c8760e0d2 in perf_config_from_file util/config.c:476
#5 0x560c876108fd in perf_config_set__init util/config.c:661
#6 0x560c87610c72 in perf_config_set__new util/config.c:709
#7 0x560c87610d2f in perf_config__init util/config.c:718
#8 0x560c87610e5d in perf_config util/config.c:730
#9 0x560c875ddea0 in main /home/changbin/work/linux/tools/perf/perf.c:442
#10 0x7ff3afb8609a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)
Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Taeung Song <treeze.taeung@gmail.com> Fixes: 20105ca1240c ("perf config: Introduce perf_config_set class") Link: http://lkml.kernel.org/r/20190316080556.3075-6-changbin.du@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
turbostat failed to return a non-zero exit status even though the
supplied command (turbostat <command>) failed. Currently when turbostat
forks a command it returns zero instead of the actual exit status of the
command. Modify the code to return the exit status.
Signed-off-by: David Arcari <darcari@redhat.com> Acked-by: Len Brown <len.brown@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
int3400 only pushes the UUID into the firmware when the mode is flipped
to "enable". The current code only exposes the mode flag if the firmware
supports the PASSIVE_1 UUID, which not all machines do. Remove the
restriction.
The function snd_opl3_drum_switch declaration in the header file
has the order of the two arguments on_off and vel swapped when
compared to the definition arguments of vel and on_off. Fix this
by swapping them around to match the definition.
This error predates the git history, so no idea when this error
was introduced.
Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
WARNING: vmlinux.o(.text+0x5e4250): Section mismatch in reference from the function davinci_mmcsd_probe() to the function .init.text:init_mmcsd_host()
The function davinci_mmcsd_probe() references
the function __init init_mmcsd_host().
This is often because davinci_mmcsd_probe lacks a __init
annotation or the annotation of init_mmcsd_host is wrong.
Code review revealed a race condition which could allow the catas error
flow to interrupt the alias guid query post mechanism at random points.
Thiis is fixed by doing cancel_delayed_work_sync() instead of
cancel_delayed_work() during the alias guid mechanism destroy flow.
Fixes: a0c64a17aba8 ("mlx4: Add alias_guid mechanism") Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Currently when the file system resize using ext4_resize_fs() fails it
will report into log that "resized filesystem to <requested block
count>". However this may not be true in the case of failure. Use the
current block count as returned by ext4_blocks_count() to report the
block count.
Additionally, report a warning that "error occurred during file system
resize"
Currently in add_new_gdb_meta_bg() there is a missing brelse of gdb_bh
in case ext4_journal_get_write_access() fails.
Additionally kvfree() is missing in the same error path. Fix it by
moving the ext4_journal_get_write_access() before the ext4 sb update as
Ted suggested and release n_group_desc and gdb_bh in case it fails.
On mmap(), perf_events generates a RECORD_MMAP record and then checks
which events are interested in this record. There are currently 2
versions of mmap records: RECORD_MMAP and RECORD_MMAP2. MMAP2 is larger.
The event configuration controls which version the user level tool
accepts.
If the event->attr.mmap2=1 field then MMAP2 record is returned. The
perf_event_mmap_output() takes care of this. It checks attr->mmap2 and
corrects the record fields before putting it in the sampling buffer of
the event. At the end the function restores the modified MMAP record
fields.
The problem is that the function restores the size but not the type.
Thus, if a subsequent event only accepts MMAP type, then it would
instead receive an MMAP2 record with a size of MMAP record.
This patch fixes the problem by restoring the record type on exit.
Signed-off-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@linux.intel.com> Fixes: 13d7a2410fa6 ("perf: Add attr->mmap2 attribute to an event") Link: http://lkml.kernel.org/r/20190307185233.225521-1-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
In case of devboards we really often disable bootloader and load
Linux image in memory via JTAG. Even if kernel tries to verify
uboot_tag and uboot_arg there is sill a chance that we treat some
garbage in registers as valid u-boot arguments in JTAG case.
E.g. it is enough to have '1' in r0 to treat any value in r2 as
a boot command line.
So check that magic number passed from u-boot is correct and drop
u-boot arguments otherwise. That helps to reduce the possibility
of using garbage as u-boot arguments in JTAG case.
We can safely check U-boot magic value (0x0) in linux passed via
r1 register as U-boot pass it from the beginning. So there is no
backward-compatibility issues.
There is a Marvell 88SE9170 PCIe SATA controller I found on a board here.
Some quick testing with the ARM SMMU enabled reveals that it suffers from
the same requester ID mixup problems as the other Marvell chips listed
already.
Add the PCI vendor/device ID to the list of chips which need the
workaround.
return_address returns the address that is one level higher in the call
stack than requested in its argument, because level 0 corresponds to its
caller's return address. Use requested level as the number of stack
frames to skip.
This fixes the address reported by might_sleep and friends.
Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A NULL pointer dereference bug was reported on a distribution kernel but
the same issue should be present on mainline kernel. It occured on s390
but should not be arch-specific. A partial oops looks like:
Unable to handle kernel pointer dereference in virtual kernel address space
...
Call Trace:
...
try_to_wake_up+0xfc/0x450
vhost_poll_wakeup+0x3a/0x50 [vhost]
__wake_up_common+0xbc/0x178
__wake_up_common_lock+0x9e/0x160
__wake_up_sync_key+0x4e/0x60
sock_def_readable+0x5e/0x98
The bug hits any time between 1 hour to 3 days. The dereference occurs
in update_cfs_rq_h_load when accumulating h_load. The problem is that
cfq_rq->h_load_next is not protected by any locking and can be updated
by parallel calls to task_h_load. Depending on the compiler, code may be
generated that re-reads cfq_rq->h_load_next after the check for NULL and
then oops when reading se->avg.load_avg. The dissassembly showed that it
was possible to reread h_load_next after the check for NULL.
While this does not appear to be an issue for later compilers, it's still
an accident if the correct code is generated. Full locking in this path
would have high overhead so this patch uses READ_ONCE to read h_load_next
only once and check for NULL before dereferencing. It was confirmed that
there were no further oops after 10 days of testing.
As Peter pointed out, it is also necessary to use WRITE_ONCE() to avoid any
potential problems with store tearing.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Fixes: 685207963be9 ("sched: Move h_load calculation to task_h_load()") Link: https://lkml.kernel.org/r/20190319123610.nsivgf3mjbjjesxb@techsingularity.net Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The "call" variable comes from the user in privcmd_ioctl_hypercall().
It's an offset into the hypercall_page[] which has (PAGE_SIZE / 32)
elements. We need to put an upper bound on it to prevent an out of
bounds access.
Rather embarrassingly, our futex() FUTEX_WAKE_OP implementation doesn't
explicitly set the return value on the non-faulting path and instead
leaves it holding the result of the underlying atomic operation. This
means that any FUTEX_WAKE_OP atomic operation which computes a non-zero
value will be reported as having failed. Regrettably, I wrote the buggy
code back in 2011 and it was upstreamed as part of the initial arm64
support in 2012.
The reasons we appear to get away with this are:
1. FUTEX_WAKE_OP is rarely used and therefore doesn't appear to get
exercised by futex() test applications
2. If the result of the atomic operation is zero, the system call
behaves correctly
3. Prior to version 2.25, the only operation used by GLIBC set the
futex to zero, and therefore worked as expected. From 2.25 onwards,
FUTEX_WAKE_OP is not used by GLIBC at all.
Fix the implementation by ensuring that the return value is either 0
to indicate that the atomic operation completed successfully, or -EFAULT
if we encountered a fault when accessing the user mapping.
vring_create_virtqueue() allows the caller to specify via the
may_reduce_num parameter whether the vring code is allowed to
allocate a smaller ring than specified.
However, the split ring allocation code tries to allocate a
smaller ring on allocation failure regardless of what the
caller specified. This may cause trouble for e.g. virtio-pci
in legacy mode, which does not support ring resizing. (The
packed ring code does not resize in any case.)
Let's fix this by bailing out immediately in the split ring code
if the requested size cannot be allocated and may_reduce_num has
not been specified.
While at it, fix a typo in the usage instructions.
If a child irqchip calls irq_chip_set_wake_parent() but its parent irqchip
has the IRQCHIP_SKIP_SET_WAKE flag set an error is returned.
This is inconsistent behaviour vs. set_irq_wake_real() which returns 0 when
the irqchip has the IRQCHIP_SKIP_SET_WAKE flag set. It doesn't attempt to
walk the chain of parents and set irq wake on any chips that don't have the
flag set either. If the intent is to call the .irq_set_wake() callback of
the parent irqchip, then we expect irqchip implementations to omit the
IRQCHIP_SKIP_SET_WAKE flag and implement an .irq_set_wake() function that
calls irq_chip_set_wake_parent().
The problem has been observed on a Qualcomm sdm845 device where set wake
fails on any GPIO interrupts after applying work in progress wakeup irq
patches to the GPIO driver. The chain of chips looks like this:
QCOM GPIO -> QCOM PDC (SKIP) -> ARM GIC (SKIP)
The GPIO controllers parent is the QCOM PDC irqchip which in turn has ARM
GIC as parent. The QCOM PDC irqchip has the IRQCHIP_SKIP_SET_WAKE flag
set, and so does the grandparent ARM GIC.
The GPIO driver doesn't know if the parent needs to set wake or not, so it
unconditionally calls irq_chip_set_wake_parent() causing this function to
return a failure because the parent irqchip (PDC) doesn't have the
.irq_set_wake() callback set. Returning 0 instead makes everything work and
irqs from the GPIO controller can be configured for wakeup.
Make it consistent by returning 0 (success) from irq_chip_set_wake_parent()
when a parent chip has IRQCHIP_SKIP_SET_WAKE set.
Whan a filesystem is mounted with the nologreplay mount option, which
requires it to be mounted in RO mode as well, we can not allow discard on
free space inside block groups, because log trees refer to extents that
are not pinned in a block group's free space cache (pinning the extents is
precisely the first phase of replaying a log tree).
So do not allow the fitrim ioctl to do anything when the filesystem is
mounted with the nologreplay option, because later it can be mounted RW
without that option, which causes log replay to happen and result in
either a failure to replay the log trees (leading to a mount failure), a
crash or some silent corruption.
Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Fixes: 96da09192cda ("btrfs: Introduce new mount option to disable tree log replay") CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is very low possibility ( < 0.1% ) that channel swap happened
in beginning when multi output/input pin is enabled. The issue is
that hardware can't send data to correct pin in the beginning with
the normal enable flow.
This is hardware issue, but there is no errata, the workaround flow
is that: Each time playback/recording, firstly clear the xSMA/xSMB,
then enable TE/RE, then enable xSMB and xSMA (xSMB must be enabled
before xSMA). Which is to use the xSMA as the trigger start register,
previously the xCR_TE or xCR_RE is the bit for starting.
Fixes commit 43d24e76b698 ("ASoC: fsl_esai: Add ESAI CPU DAI driver") Cc: <stable@vger.kernel.org> Reviewed-by: Fabio Estevam <festevam@gmail.com> Acked-by: Nicolin Chen <nicoleotsuka@gmail.com> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
clang points out with hundreds of warnings that the bitrev macros have a
problem with constant input:
drivers/hwmon/sht15.c:187:11: error: variable '__x' is uninitialized when used within its own initialization
[-Werror,-Wuninitialized]
u8 crc = bitrev8(data->val_status & 0x0F);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/bitrev.h:102:21: note: expanded from macro 'bitrev8'
__constant_bitrev8(__x) : \
~~~~~~~~~~~~~~~~~~~^~~~
include/linux/bitrev.h:67:11: note: expanded from macro '__constant_bitrev8'
u8 __x = x; \
~~~ ^
Both the bitrev and the __constant_bitrev macros use an internal
variable named __x, which goes horribly wrong when passing one to the
other.
The obvious fix is to rename one of the variables, so this adds an extra
'_'.
It seems we got away with this because
- there are only a few drivers using bitrev macros
- usually there are no constant arguments to those
- when they are constant, they tend to be either 0 or (unsigned)-1
(drivers/isdn/i4l/isdnhdlc.o, drivers/iio/amplifiers/ad8366.c) and
give the correct result by pure chance.
In fact, the only driver that I could find that gets different results
with this is drivers/net/wan/slic_ds26522.c, which in turn is a driver
for fairly rare hardware (adding the maintainer to Cc for testing).
Link: http://lkml.kernel.org/r/20190322140503.123580-1-arnd@arndb.de Fixes: 556d2f055bf6 ("ARM: 8187/1: add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: Zhao Qiang <qiang.zhao@nxp.com> Cc: Yalin Wang <yalin.wang@sonymobile.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While adding LASI support to QEMU, I noticed that the QEMU detection in
the kernel happens much too late. For example, when a LASI chip is found
by the kernel, it registers the LASI LED driver as well. But when we
run on QEMU it makes sense to avoid spending unnecessary CPU cycles, so
we need to access the running_on_QEMU flag earlier than before.
This patch now makes the QEMU detection the fist task of the Linux
kernel by moving it to where the kernel enters the C-coding.
When ioctl calls are made with non-null-terminated userspace strings,
strlcpy causes an OOB-read from within strlen. Fix by changing to use
strscpy instead.
The device type for ip6 tunnels is set to
ARPHRD_TUNNEL6. However, the ip4ip6_err function
is expecting the device type of the tunnel to be
ARPHRD_TUNNEL. Since the device types do not
match, the function exits and the ICMP error
packet is not sent to the originating host. Note
that the device type for IPv4 tunnels is set to
ARPHRD_TUNNEL.
Fix is to expect a tunnel device type of
ARPHRD_TUNNEL6 instead. Now the tunnel device
type matches and the ICMP error packet is sent
to the originating host.
Signed-off-by: Sheena Mira-ato <sheena.mira-ato@alliedtelesis.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
NULL or ZERO_SIZE_PTR will be returned for zero sized memory
request, and derefencing them will lead to a segfault
so it is unnecessory to call vzalloc for zero sized memory
request and not call functions which maybe derefence the
NULL allocated memory
this also fixes a possible memory leak if phy_ethtool_get_stats
returns error, memory should be freed before exit
Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Wang Li <wangli39@baidu.com> Reviewed-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net_hash_mix() currently uses kernel address of a struct net,
and is used in many places that could be used to reveal this
address to a patient attacker, thus defeating KASLR, for
the typical case (initial net namespace, &init_net is
not dynamically allocated)
I believe the original implementation tried to avoid spending
too many cycles in this function, but security comes first.
Also provide entropy regardless of CONFIG_NET_NS.
Fixes: 0b4419162aa6 ("netns: introduce the net_hash_mix "salt" for hashes") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Amit Klein <aksecurity@gmail.com> Reported-by: Benny Pinkas <benny@pinkas.net> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is logic to check that the RX/TPA consumer index is the expected
index to work around a hardware problem. However, the potentially bad
consumer index is first used to index into an array to reference an entry.
This can potentially crash if the bad consumer index is beyond legal
range. Improve the logic to use the consumer index for dereferencing
after the validity check and log an error message.
Fixes: fa7e28127a5a ("bnxt_en: Add workaround to detect bad opaque in rx completion (part 2)") Signed-off-by: Michael Chan <michael.chan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the RX completion indicates RX buffers errors, the RX ring will be
disabled by firmware and no packets will be received on that ring from
that point on. Recover by resetting the device.
Fixes: c0c050c58d84 ("bnxt_en: New Broadcom ethernet driver.") Signed-off-by: Michael Chan <michael.chan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Configuration check to accept source route IP options should be made on
the incoming netdevice when the skb->dev is an l3mdev master. The route
lookup for the source route next hop also needs the incoming netdev.
v2->v3:
- Simplify by passing the original netdevice down the stack (per David
Ahern).
Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
RFC8257 §3.5 explicitly states that "A DCTCP sender MUST react to
loss episodes in the same way as conventional TCP".
Currently, Linux DCTCP performs no cwnd reduction when losses
are encountered. Optionally, the dctcp_clamp_alpha_on_loss resets
alpha to its maximal value if a RTO happens. This behavior
is sub-optimal for at least two reasons: i) it ignores losses
triggering fast retransmissions; and ii) it causes unnecessary large
cwnd reduction in the future if the loss was isolated as it resets
the historical term of DCTCP's alpha EWMA to its maximal value (i.e.,
denoting a total congestion). The second reason has an especially
noticeable effect when using DCTCP in high BDP environments, where
alpha normally stays at low values.
This patch replace the clamping of alpha by setting ssthresh to
half of cwnd for both fast retransmissions and RTOs, at most once
per RTT. Consequently, the dctcp_clamp_alpha_on_loss module parameter
has been removed.
The table below shows experimental results where we measured the
drop probability of a PIE AQM (not applying ECN marks) at a
bottleneck in the presence of a single TCP flow with either the
alpha-clamping option enabled or the cwnd halving proposed by this
patch. Results using reno or cubic are given for comparison.
We see that, without halving its cwnd for all source of losses,
DCTCP drives the AQM to large drop probabilities in order to keep
the queue length under control (i.e., it repeatedly faces RTOs).
Instead, if DCTCP reacts to all source of losses, it can then be
controlled by the AQM using similar drop levels than cubic or reno.
Signed-off-by: Koen De Schepper <koen.de_schepper@nokia-bell-labs.com> Signed-off-by: Olivier Tilmans <olivier.tilmans@nokia-bell-labs.com> Cc: Bob Briscoe <research@bobbriscoe.net> Cc: Lawrence Brakmo <brakmo@fb.com> Cc: Florian Westphal <fw@strlen.de> Cc: Daniel Borkmann <borkmann@iogearbox.net> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Andrew Shewmaker <agshew@gmail.com> Cc: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Florian Westphal <fw@strlen.de> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
BUG: KMSAN: kernel-infoleak in _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32
Call Trace:
_copy_to_user+0x16b/0x1f0 lib/usercopy.c:32
copy_to_user include/linux/uaccess.h:174 [inline]
sctp_getsockopt_peer_addrs net/sctp/socket.c:5911 [inline]
sctp_getsockopt+0x1668e/0x17f70 net/sctp/socket.c:7562
...
Uninit was stored to memory at:
sctp_transport_init net/sctp/transport.c:61 [inline]
sctp_transport_new+0x16d/0x9a0 net/sctp/transport.c:115
sctp_assoc_add_peer+0x532/0x1f70 net/sctp/associola.c:637
sctp_process_param net/sctp/sm_make_chunk.c:2548 [inline]
sctp_process_init+0x1a1b/0x3ed0 net/sctp/sm_make_chunk.c:2361
...
Bytes 8-15 of 16 are uninitialized
It was caused by that th _pad field (the 8-15 bytes) of a v4 addr (saved in
struct sockaddr_in) wasn't initialized, but directly copied to user memory
in sctp_getsockopt_peer_addrs().
So fix it by calling memset(addr->v4.sin_zero, 0, 8) to initialize _pad of
sockaddr_in before copying it to user memory in sctp_v4_addr_to_user(), as
sctp_v6_addr_to_user() does.
Reported-by: syzbot+86b5c7c236a22616a72f@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Tested-by: Alexander Potapenko <glider@google.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The flow action buffer can be resized if it's not big enough to contain
all the requested flow actions. However, this resize doesn't take into
account the new requested size, the buffer is only increased by a factor
of 2x. This might be not enough to contain the new data, causing a
buffer overflow, for example:
Fix by making sure the new buffer is properly resized to contain all the
requested data.
BugLink: https://bugs.launchpad.net/bugs/1813244 Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Acked-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When it is to cleanup net namespace, rds_tcp_exit_net() will call
rds_tcp_kill_sock(), if t_sock is NULL, it will not call
rds_conn_destroy(), rds_conn_path_destroy() and rds_tcp_conn_free() to free
connection, and the worker cp_conn_w is not stopped, afterwards the net is freed in
net_drop_ns(); While cp_conn_w rds_connect_worker() will call rds_tcp_conn_path_connect()
and reference 'net' which has already been freed.
In rds_tcp_conn_path_connect(), rds_tcp_set_callbacks() will set t_sock = sock before
sock->ops->connect, but if connect() is failed, it will call
rds_tcp_restore_callbacks() and set t_sock = NULL, if connect is always
failed, rds_connect_worker() will try to reconnect all the time, so
rds_tcp_kill_sock() will never to cancel worker cp_conn_w and free the
connections.
Therefore, the condition !tc->t_sock is not needed if it is going to do
cleanup_net->rds_tcp_exit_net->rds_tcp_kill_sock, because tc->t_sock is always
NULL, and there is on other path to cancel cp_conn_w and free
connection. So this patch is to fix this.
rds_tcp_kill_sock():
...
if (net != c_net || !tc->t_sock)
... Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
==================================================================
BUG: KASAN: use-after-free in inet_create+0xbcc/0xd28
net/ipv4/af_inet.c:340
Read of size 4 at addr ffff8003496a4684 by task kworker/u8:4/3721
Fixes: 467fa15356ac("RDS-TCP: Support multiple RDS-TCP listen endpoints, one per netns.") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When kcm is loaded while many processes try to create a KCM socket, a
crash occurs:
BUG: unable to handle kernel NULL pointer dereference at 000000000000000e
IP: mutex_lock+0x27/0x40 kernel/locking/mutex.c:240
PGD 8000000016ef2067 P4D 8000000016ef2067 PUD 3d6e9067 PMD 0
Oops: 0002 [#1] SMP KASAN PTI
CPU: 0 PID: 7005 Comm: syz-executor.5 Not tainted 4.12.14-396-default #1 SLE15-SP1 (unreleased)
RIP: 0010:mutex_lock+0x27/0x40 kernel/locking/mutex.c:240
RSP: 0018:ffff88000d487a00 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 000000000000000e RCX: 1ffff100082b0719
...
CR2: 000000000000000e CR3: 000000004b1bc003 CR4: 0000000000060ef0
Call Trace:
kcm_create+0x600/0xbf0 [kcm]
__sock_create+0x324/0x750 net/socket.c:1272
...
This is due to race between sock_create and unfinished
register_pernet_device. kcm_create tries to do "net_generic(net,
kcm_net_id)". but kcm_net_id is not initialized yet.
So switch the order of the two to close the race.
This can be reproduced with mutiple processes doing socket(PF_KCM, ...)
and one process doing module removal.
Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module") Reviewed-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipip6 tunnels run iptunnel_pull_header on received skbs. This can
determine the following use-after-free accessing iph pointer since
the packet will be 'uncloned' running pskb_expand_head if it is a
cloned gso skb (e.g if the packet has been sent though a veth device)
Fix it resetting iph pointer after iptunnel_pull_header
Fixes: a09a4c8dd1ec ("tunnels: Remove encapsulation offloads on decap") Tested-by: Jianlin Shi <jishi@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At the beginning of ip6_fragment func, the prevhdr pointer is
obtained in the ip6_find_1stfragopt func.
However, all the pointers pointing into skb header may change
when calling skb_checksum_help func with
skb->ip_summed = CHECKSUM_PARTIAL condition.
The prevhdr pointe will be dangling if it is not reloaded after
calling __skb_linearize func in skb_checksum_help func.
Here, I add a variable, nexthdr_offset, to evaluate the offset,
which does not changes even after calling __skb_linearize func.
Fixes: 405c92f7a541 ("ipv6: add defensive check for CHECKSUM_PARTIAL skbs in ip_fragment") Signed-off-by: Junwei Hu <hujunwei4@huawei.com> Reported-by: Wenhao Zhang <zhangwenhao8@huawei.com> Reported-by: syzbot+e8ce541d095e486074fc@syzkaller.appspotmail.com Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
By default, the kernel will automatically load the module of any line
dicipline that is asked for. As this sometimes isn't the safest thing
to do, provide a sysctl to disable this feature.
By default, we set this to 'y' as that is the historical way that Linux
has worked, and we do not want to break working systems. But in the
future, perhaps this can default to 'n' to prevent this functionality.
The n_r3964 line discipline driver was written in a different time, when
SMP machines were rare, and users were trusted to do the right thing.
Since then, the world has moved on but not this code, it has stayed
rooted in the past with its lovely hand-crafted list structures and
loads of "interesting" race conditions all over the place.
After attempting to clean up most of the issues, I just gave up and am
now marking the driver as BROKEN so that hopefully someone who has this
hardware will show up out of the woodwork (I know you are out there!)
and will help with debugging a raft of changes that I had laying around
for the code, but was too afraid to commit as odds are they would break
things.
Many thanks to Jann and Linus for pointing out the initial problems in
this codebase, as well as many reviews of my attempts to fix the issues.
It was a case of whack-a-mole, and as you can see, the mole won.
When KASLR is enabled (CONFIG_RANDOMIZE_BASE=y), the top 4K of kernel
virtual address space may be mapped to physical addresses despite being
reserved for ERR_PTR values.
Fix the randomization of the linear region so that we avoid mapping the
last page of the virtual address space.
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: liyueyi <liyueyi@live.com>
[will: rewrote commit message; merged in suggestion from Ard] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
When I updated the spectre_v2 reporting to handle software count cache
flush I got the logic wrong when there's no software count cache
enabled at all.
The result is that on systems with the software count cache flush
disabled we print:
Which correctly indicates that the count cache is disabled, but
incorrectly says the software count cache flush is enabled.
The root of the problem is that we are trying to handle all
combinations of options. But we know now that we only expect to see
the software count cache flush enabled if the other options are false.
So split the two cases, which simplifies the logic and fixes the bug.
We were also missing a space before "(hardware accelerated)".
The commit identified below adds MC_BTB_FLUSH macro only when
CONFIG_PPC_FSL_BOOK3E is defined. This results in the following error
on some configs (seen several times with kisskb randconfig_defconfig)
Fixed the following build warning:
powerpc-linux-gnu-ld: warning: orphan section `__btb_flush_fixup' from
`arch/powerpc/kernel/head_44x.o' being placed in section
`__btb_flush_fixup'.
In order to protect against speculation attacks on
indirect branches, the branch predictor is flushed at
kernel entry to protect for the following situations:
- userspace process attacking another userspace process
- userspace process attacking the kernel
Basically when the privillege level change (i.e.the kernel
is entered), the branch predictor state is flushed.
In order to protect against speculation attacks on
indirect branches, the branch predictor is flushed at
kernel entry to protect for the following situations:
- userspace process attacking another userspace process
- userspace process attacking the kernel
Basically when the privillege level change (i.e. the
kernel is entered), the branch predictor state is flushed.
In order to flush the branch predictor the guest kernel performs
writes to the BUCSR register which is hypervisor privilleged. However,
the branch predictor is flushed at each KVM entry, so the branch
predictor has been already flushed, so just return as soon as possible
to guest.
In order to protect against speculation attacks (Spectre
variant 2) on NXP PowerPC platforms, the branch predictor
should be flushed when the privillege level is changed.
This patch is adding the infrastructure to fixup at runtime
the code sections that are performing the branch predictor flush
depending on a boot arg parameter which is added later in a
separate patch.
Look for fw-features properties to determine the appropriate settings
for the count cache flush, and then call the generic powerpc code to
set it up based on the security feature flags.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
Use the existing hypercall to determine the appropriate settings for
the count cache flush, and then call the generic powerpc code to set
it up based on the security feature flags.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
Some CPU revisions support a mode where the count cache needs to be
flushed by software on context switch. Additionally some revisions may
have a hardware accelerated flush, in which case the software flush
sequence can be shortened.
If we detect the appropriate flag from firmware we patch a branch
into _switch() which takes us to a count cache flush sequence.
That sequence in turn may be patched to return early if we detect that
the CPU supports accelerating the flush sequence in hardware.
Add debugfs support for reporting the state of the flush, as well as
runtime disabling it.
And modify the spectre_v2 sysfs file to report the state of the
software flush.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
Add security feature flags to indicate the need for software to flush
the count cache on context switch, and for the presence of a hardware
assisted count cache flush.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
Add a macro and some helper C functions for patching single asm
instructions.
The gas macro means we can do something like:
1: nop
patch_site 1b, patch__foo
Which is less visually distracting than defining a GLOBAL symbol at 1,
and also doesn't pollute the symbol table which can confuse eg. perf.
These are obviously similar to our existing feature sections, but are
not automatically patched based on CPU/MMU features, rather they are
designed to be manually patched by C code at some arbitrary point.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
In a subsequent patch we will enable building security.c for Book3E.
However the NXP platforms are not vulnerable to Meltdown, so make the
Meltdown vulnerability reporting PPC_BOOK3S_64 specific.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
[mpe: Split out of larger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
Currently we require platform code to call setup_barrier_nospec(). But
if we add an empty definition for the !CONFIG_PPC_BARRIER_NOSPEC case
then we can call it in setup_arch().
Add a config symbol to encode which platforms support the
barrier_nospec speculation barrier. Currently this is just Book3S 64
but we will add Book3E in a future patch.
When I added the spectre_v2 information in sysfs, I included the
availability of the ori31 speculation barrier.
Although the ori31 barrier can be used to mitigate v2, it's primarily
intended as a spectre v1 mitigation. Spectre v2 is mitigated by
hardware changes.
So rework the sysfs files to show the ori31 information in the
spectre_v1 file, rather than v2.
See commit 304ec1b05031 ("x86/uaccess: Use __uaccess_begin_nospec()
and uaccess_try_nospec") and b3bbfb3fb5d2 ("x86: Introduce
__uaccess_begin_nospec() and uaccess_try_nospec") for more detail.
In all cases we are ordering the load from the potentially
user-controlled pointer vs a previous branch based on an access_ok()
check or similar.
Base on a patch from Michal Suchanek.
Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
This stops us from doing code patching in init sections after they've
been freed.
In this chain:
kvm_guest_init() ->
kvm_use_magic_page() ->
fault_in_pages_readable() ->
__get_user() ->
__get_user_nocheck() ->
barrier_nospec();
We have a code patching location at barrier_nospec() and
kvm_guest_init() is an init function. This whole chain gets inlined,
so when we free the init section (hence kvm_guest_init()), this code
goes away and hence should no longer be patched.
We seen this as userspace memory corruption when using a memory
checker while doing partition migration testing on powervm (this
starts the code patching post migration via
/sys/kernel/mobility/migration). In theory, it could also happen when
using /sys/kernel/debug/powerpc/barrier_nospec.
Cc: stable@vger.kernel.org # 4.13+ Signed-off-by: Michael Neuling <mikey@neuling.org> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
Based on the RFI patching. This is required to be able to disable the
speculation barrier.
Only one barrier type is supported and it does nothing when the
firmware does not enable it. Also re-patching modules is not supported
So the only meaningful thing that can be done is patching out the
speculation barrier at boot when the user says it is not wanted.
Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
A no-op form of ori (or immediate of 0 into r31 and the result stored
in r31) has been re-tasked as a speculation barrier. The instruction
only acts as a barrier on newer machines with appropriate firmware
support. On older CPUs it remains a harmless no-op.
Implement barrier_nospec using this instruction.
mpe: The semantics of the instruction are believed to be that it
prevents execution of subsequent instructions until preceding branches
have been fully resolved and are no longer executing speculatively.
There is no further documentation available at this time.
Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
In practice these are almost all uses of r0 that should just be a
literal 0.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
[mpe: Mention r0 is almost always the culprit, fold in purgatory change] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>