There could be a race between task exit and probe unregister:
exit_mm()
mmput()
__mmput() uprobe_unregister()
uprobe_clear_state() put_uprobe()
delayed_uprobe_remove() delayed_uprobe_remove()
put_uprobe() is calling delayed_uprobe_remove() without taking
delayed_uprobe_lock and thus the race sometimes results in a
kernel crash. Fix this by taking delayed_uprobe_lock before
calling delayed_uprobe_remove() from put_uprobe().
Detailed crash log can be found at:
Link: http://lkml.kernel.org/r/000000000000140c370577db5ece@google.com
Link: http://lkml.kernel.org/r/20181205033423.26242-1-ravi.bangoria@linux.ibm.com
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reported-by: syzbot+cb1fb754b771caca0a88@syzkaller.appspotmail.com
Fixes: 1cc33161a8 ("uprobes: Support SDT markers having reference count (semaphore)")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Function graph tracing recurses into itself when stackleak is enabled,
causing the ftrace graph selftest to run for up to 90 seconds and
trigger the softlockup watchdog.
Breakpoint 2, ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:200
200 mcount_get_lr_addr x0 // pointer to function's saved lr
(gdb) bt
\#0 ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:200
\#1 0xffffff80081d5280 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:153
\#2 0xffffff8008555484 in stackleak_track_stack () at ../kernel/stackleak.c:106
\#3 0xffffff8008421ff8 in ftrace_ops_test (ops=0xffffff8009eaa840 <graph_ops>, ip=18446743524091297036, regs=<optimized out>) at ../kernel/trace/ftrace.c:1507
\#4 0xffffff8008428770 in __ftrace_ops_list_func (regs=<optimized out>, ignored=<optimized out>, parent_ip=<optimized out>, ip=<optimized out>) at ../kernel/trace/ftrace.c:6286
\#5 ftrace_ops_no_ops (ip=18446743524091297036, parent_ip=18446743524091242824) at ../kernel/trace/ftrace.c:6321
\#6 0xffffff80081d5280 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:153
\#7 0xffffff800832fd10 in irq_find_mapping (domain=0xffffffc03fc4bc80, hwirq=27) at ../kernel/irq/irqdomain.c:876
\#8 0xffffff800832294c in __handle_domain_irq (domain=0xffffffc03fc4bc80, hwirq=27, lookup=true, regs=0xffffff800814b840) at ../kernel/irq/irqdesc.c:650
\#9 0xffffff80081d52b4 in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:205
Rework so we mark stackleak_track_stack as notrace
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
The later patch will introduce "struct bpf_line_info" which
has member "line_off" and "file_off" referring back to the
string section in btf. The line_"off" and file_"off"
are more consistent to the naming convention in btf.h that
means "offset" (e.g. name_off in "struct btf_type").
The to-be-added "struct bpf_line_info" also has another
member, "insn_off" which is the same as the "insn_offset"
in "struct bpf_func_info". Hence, this patch renames "insn_offset"
to "insn_off" for "struct bpf_func_info".
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
1) When bpf_dump_raw_ok() == false and the kernel can provide >=1
func_info to the userspace, the current behavior is setting
the info.func_info_cnt to 0 instead of setting info.func_info
to 0.
It is different from the behavior in jited_func_lens/nr_jited_func_lens,
jited_ksyms/nr_jited_ksyms...etc.
This patch fixes it. (i.e. set func_info to 0 instead of
func_info_cnt to 0 when bpf_dump_raw_ok() == false).
2) When the userspace passed in info.func_info_cnt == 0, the kernel
will set the expected func_info size back to the
info.func_info_rec_size. It is a way for the userspace to learn
the kernel expected func_info_rec_size introduced in
commit 838e96904f ("bpf: Introduce bpf_func_info").
An exception is the kernel expected size is not set when
func_info is not available for a bpf_prog. This makes the
returned info.func_info_rec_size has different values
depending on the returned value of info.func_info_cnt.
This patch sets the kernel expected size to info.func_info_rec_size
independent of the info.func_info_cnt.
3) The current logic only rejects invalid func_info_rec_size if
func_info_cnt is non zero. This patch also rejects invalid
nonzero info.func_info_rec_size and not equal to the kernel
expected size.
4) Set info.btf_id as long as prog->aux->btf != NULL. That will
setup the later copy_to_user() codes look the same as others
which then easier to understand and maintain.
prog->aux->btf is not NULL only if prog->aux->func_info_cnt > 0.
Breaking up info.btf_id from prog->aux->func_info_cnt is needed
for the later line info patch anyway.
A similar change is made to bpf_get_prog_name().
Fixes: 838e96904f ("bpf: Introduce bpf_func_info")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Alexei Starovoitov says:
====================
pull-request: bpf 2018-12-05
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) fix bpf uapi pointers for 32-bit architectures, from Daniel.
2) improve verifer ability to handle progs with a lot of branches, from Alexei.
3) strict btf checks, from Yonghong.
4) bpf_sk_lookup api cleanup, from Joe.
5) other misc fixes
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
By default, BPF uses module_alloc() to allocate executable memory,
but this is not necessary on all arches and potentially undesirable
on some of them.
So break out the module_alloc() and module_memfree() calls into __weak
functions to allow them to be overridden in arch code.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Commit bfd56cd605 ("dma-mapping: support highmem in the generic remap
allocator") replaced dma_direct_alloc_pages() with __dma_direct_alloc_pages(),
which doesn't set dma_handle and zero allocated memory. Fix it by doing this
directly in the caller function.
Fixes: bfd56cd605 ("dma-mapping: support highmem in the generic remap allocator")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
tk_core.seq is initialized open coded, but that misses to initialize the
lockdep map when lockdep is enabled. Lockdep splats involving tk_core seq
consequently lack a name and are hard to read.
Use the proper initializer which takes care of the lockdep map
initialization.
[ tglx: Massaged changelog ]
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: tj@kernel.org
Cc: johannes.berg@intel.com
Link: https://lkml.kernel.org/r/20181128234325.110011-12-bvanassche@acm.org
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Merge tag 'v4.20-rc5' into for-4.21/block
Pull in v4.20-rc5, solving a conflict we'll otherwise get in aio.c and
also getting the merge fix that went into mainline that users are
hitting testing for-4.21/block and/or for-next.
* tag 'v4.20-rc5': (664 commits)
Linux 4.20-rc5
PCI: Fix incorrect value returned from pcie_get_speed_cap()
MAINTAINERS: Update linux-mips mailing list address
ocfs2: fix potential use after free
mm/khugepaged: fix the xas_create_range() error path
mm/khugepaged: collapse_shmem() do not crash on Compound
mm/khugepaged: collapse_shmem() without freezing new_page
mm/khugepaged: minor reorderings in collapse_shmem()
mm/khugepaged: collapse_shmem() remember to clear holes
mm/khugepaged: fix crashes due to misaccounted holes
mm/khugepaged: collapse_shmem() stop if punched or truncated
mm/huge_memory: fix lockdep complaint on 32-bit i_size_read()
mm/huge_memory: splitting set mapping+index before unfreeze
mm/huge_memory: rename freeze_page() to unmap_page()
initramfs: clean old path before creating a hardlink
kernel/kcov.c: mark funcs in __sanitizer_cov_trace_pc() as notrace
psi: make disabling/enabling easier for vendor kernels
proc: fixup map_files test on arm
debugobjects: avoid recursive calls with kmemleak
userfaultfd: shmem: UFFDIO_COPY: set the page dirty if VM_WRITE is not set
...
malicious bpf program may try to force the verifier to remember
a lot of distinct verifier states.
Put a limit to number of per-insn 'struct bpf_verifier_state'.
Note that hitting the limit doesn't reject the program.
It potentially makes the verifier do more steps to analyze the program.
It means that malicious programs will hit BPF_COMPLEXITY_LIMIT_INSNS sooner
instead of spending cpu time walking long link list.
The limit of BPF_COMPLEXITY_LIMIT_STATES==64 affects cilium progs
with slight increase in number of "steps" it takes to successfully verify
the programs:
before after
bpf_lb-DLB_L3.o 1940 1940
bpf_lb-DLB_L4.o 3089 3089
bpf_lb-DUNKNOWN.o 1065 1065
bpf_lxc-DDROP_ALL.o 28052 | 28162
bpf_lxc-DUNKNOWN.o 35487 | 35541
bpf_netdev.o 10864 10864
bpf_overlay.o 6643 6643
bpf_lcx_jit.o 38437 38437
But it also makes malicious program to be rejected in 0.4 seconds vs 6.5
Hence apply this limit to unprivileged programs only.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
pathological bpf programs may try to force verifier to explode in
the number of branch states:
20: (d5) if r1 s<= 0x24000028 goto pc+0
21: (b5) if r0 <= 0xe1fa20 goto pc+2
22: (d5) if r1 s<= 0x7e goto pc+0
23: (b5) if r0 <= 0xe880e000 goto pc+0
24: (c5) if r0 s< 0x2100ecf4 goto pc+0
25: (d5) if r1 s<= 0xe880e000 goto pc+1
26: (c5) if r0 s< 0xf4041810 goto pc+0
27: (d5) if r1 s<= 0x1e007e goto pc+0
28: (b5) if r0 <= 0xe86be000 goto pc+0
29: (07) r0 += 16614
30: (c5) if r0 s< 0x6d0020da goto pc+0
31: (35) if r0 >= 0x2100ecf4 goto pc+0
Teach verifier to recognize always taken and always not taken branches.
This analysis is already done for == and != comparison.
Expand it to all other branches.
It also helps real bpf programs to be verified faster:
before after
bpf_lb-DLB_L3.o 2003 1940
bpf_lb-DLB_L4.o 3173 3089
bpf_lb-DUNKNOWN.o 1080 1065
bpf_lxc-DDROP_ALL.o 29584 28052
bpf_lxc-DUNKNOWN.o 36916 35487
bpf_netdev.o 11188 10864
bpf_overlay.o 6679 6643
bpf_lcx_jit.o 39555 38437
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Malicious user space may try to force the verifier to use as much cpu
time and memory as possible. Hence check for pending signals
while verifying the program.
Note that suspend of sys_bpf(PROG_LOAD) syscall will lead to EAGAIN,
since the kernel has to release the resources used for program verification.
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull RCU changes from Paul E. McKenney:
- Convert RCU's BUG_ON() and similar calls to WARN_ON() and similar.
- Replace calls of RCU-bh and RCU-sched update-side functions
to their vanilla RCU counterparts. This series is a step
towards complete removal of the RCU-bh and RCU-sched update-side
functions.
( Note that some of these conversions are going upstream via their
respective maintainers. )
- Documentation updates, including a number of flavor-consolidation
updates from Joel Fernandes.
- Miscellaneous fixes.
- Automate generation of the initrd filesystem used for
rcutorture testing.
- Convert spin_is_locked() assertions to instead use lockdep.
( Note that some of these conversions are going upstream via their
respective maintainers. )
- SRCU updates, especially including a fix from Dennis Krein
for a bag-on-head-class bug.
- RCU torture-test updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since the vast majority of files (99.993% on a typical system) have no
fcaps, display "0" instead of the full zero-padded 16 hex digits in the
two PATH record cap_f* fields to save netlink bandwidth and disk space.
Simply changing the format to %x won't work since the value is two (or
possibly more in the future) 32-bit hexadecimal values concatenated and
bits in higher order values will be misrepresented.
Passes audit-testsuite and userspace tools already work fine.
Please see the github issue tracker for more details
https://github.com/linux-audit/audit-kernel/issues/101
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Fixes gcc '-Wunused-but-set-variable' warning:
kernel/cgroup/cpuset.c: In function 'cpuset_cancel_attach':
kernel/cgroup/cpuset.c:2167:17: warning:
variable 'cs' set but not used [-Wunused-but-set-variable]
It never used since introduction in commit 1f7dd3e5a6 ("cgroup: fix handling
of multi-destination migration from subtree_control enabling")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Go over the scheduler source code and fix common typos
in comments - and a typo in an actual variable name.
No change in functionality intended.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fix two typos in kernel/events/*.
No change in functionality intended.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The aux->func_info and aux->btf are leaked in the error out cases
during bpf_prog_load(). This patch fixes it.
Fixes: ba64e7d852 ("bpf: btf: support proper non-jit func info")
Cc: Yonghong Song <yhs@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The "busted" rcutorture type is an intentionally broken implementation
of RCU. Doing forward-progress testing on this implementation is not
particularly meaningful on the one hand and can result in fatal abuse
of the memory allocator on the other. This commit therefore disables
forward-progress testing of the "busted" rcutorture type.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit narrows the scope of each bucket of the forward-progress
callback-invocation histograms from one second to 100 milliseconds, which
aids debugging of forward-progress problems by making shorter-duration
callback-invocation stalls visible.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit causes the OOM handler to do rcu_barrier() calls and to
free up forward-progress callbacks in order to recover from OOM events.
The current test is terminated, but subsequent forward-progress tests can
proceed. This allows a long test to result in multiple forward-progress
failures, greatly reducing the required testing time.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit prints the age of the forward-progress test in jiffies,
in order to allow better interpretation of the callback-invocation
histograms.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
If rcutorture's forward-progress tests fail while a grace period is not
in progress, it is useful to print the time since the last grace period
ended as a way to detect failure to launch a new grace period. This
commit therefore makes this change.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
One reason why a forward-progress test might fail would be if something
prevented or delayed callback invocation. This commit therefore adds a
callback-invocation histogram printout when OOM is reported to rcutorture.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit prints out the non-zero per-CPU callback counts when a
forware-progress error (OOM event) occurs.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
[ paulmck: Fix a pair of uninitialized locals spotted by kbuild test robot. ]
The RCU CPU stall warnings print an estimate of the total number of
RCU callbacks queued in the system, but this estimate leaves out
the callbacks queued for nocbs CPUs. This commit therefore introduces
rcu_get_n_cbs_cpu(), which gives an accurate callback estimate for
both nocbs and normal CPUs, and uses this new function as needed.
This commit also introduces a rcu_get_n_cbs_nocb_cpu() helper function
that returns the number of callbacks for nocbs CPUs or zero otherwise,
and also uses this function in place of direct access to ->nocb_q_count
while in the area (fewer characters, you see).
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit adds an OOM notifier during rcutorture forward-progress
testing. If this notifier is invoked, it dumps out some grace-period
state to help debug the forward-progress problem.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Because rcutorture's forward-progress checking will trigger from an
OOM notifier, this notifier will introduce asynchronous concurrent
access to the rcu_fwd_startat variable. This commit therefore prepares
for this by converting updates to WRITE_ONCE().
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Remove return variables (declared as "ret") in cases where,
depending on whether a condition evaluates as true, the result of a
function call can be immediately returned instead of storing the result in
the return variable. When the condition evaluates as false, the constant
initially stored in the return variable at declaration is returned instead.
Signed-off-by: Pierce Griffiths <pierceagriffiths@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit affinities the forward-progress tests to avoid hogging a
housekeeping CPU on the theory that the offloaded callbacks will be
running on those housekeeping CPUs.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
[ paulmck: Fix NULL-pointer issue located by kbuild test robot. ]
Tested-by: Rong Chen <rong.a.chen@intel.com>
This commit splits rcu_torture_fwd_prog_nr() and rcu_torture_fwd_prog_cr()
functions out of rcu_torture_fwd_prog() in order to reduce indentation
pain and because rcu_torture_fwd_prog() was getting a bit too long.
In addition, this will enable easier conditional execution of the
rcu_torture_fwd_prog_cr() function, which can give false-positive
failures in some NO_HZ_FULL configurations due to overloading the
housekeeping CPUs.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Now that the forward-progress code does a full-bore continuous callback
flood lasting multiple seconds, there is little point in also posting a
mere 60,000 callbacks every second or so. This commit therefore removes
the old cbflood testing. Over time, it may be desirable to concurrently
do full-bore continuous callback floods on all CPUs simultaneously, but
one dragon at a time.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Currently, the torture scripts rely on the initrd/init script to bring
any extra CPUs online, for example, in the case where the kernel and
qemu have different ideas about how many CPUs are present. This works,
but is an unnecessary dependency on initrd, which needs to vary depending
on the distro. This commit therefore causes torture_onoff() to check
for additional CPUs, attempting to bring any found online. Errors are
ignored, just as they are by the initrd/init script.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit adds a call_rcu() flooding loop to the forward-progress test.
This emulates tight userspace loops that force call_rcu() invocations,
for example, the infamous loop containing close(open()) that instigated
the addition of blimit. If RCU does not make sufficient forward progress
in invoking the resulting flood of callbacks, rcutorture emits a warning.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
bug.2018.11.12a: Get rid of BUG_ON() and friends
consolidate.2018.12.01a: Continued RCU flavor-consolidation cleanup
doc.2018.11.12a: Documentation updates
fixes.2018.11.12a: Miscellaneous fixes
initrd.2018.11.08b: Automate creation of rcutorture initrd
sil.2018.11.12a: Remove more spin_unlock_wait() calls
Now that synchronize_rcu() waits for preempt-disable regions of code
as well as RCU read-side critical sections, synchronize_sched() can be
replaced by synchronize_rcu(). This commit therefore makes this change,
even though it is but a comment.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Now that synchronize_rcu() waits for preempt-disable regions of code
as well as RCU read-side critical sections, synchronize_sched() can be
replaced by synchronize_rcu(). This commit therefore makes this change,
even though it is but a comment.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Dennis Zhou (Facebook)" <dennisszhou@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Pull STIBP fallout fixes from Thomas Gleixner:
"The performance destruction department finally got it's act together
and came up with a cure for the STIPB regression:
- Provide a command line option to control the spectre v2 user space
mitigations. Default is either seccomp or prctl (if seccomp is
disabled in Kconfig). prctl allows mitigation opt-in, seccomp
enables the migitation for sandboxed processes.
- Rework the code to handle the conditional STIBP/IBPB control and
remove the now unused ptrace_may_access_sched() optimization
attempt
- Disable STIBP automatically when SMT is disabled
- Optimize the switch_to() logic to avoid MSR writes and invocations
of __switch_to_xtra().
- Make the asynchronous speculation TIF updates synchronous to
prevent stale mitigation state.
As a general cleanup this also makes retpoline directly depend on
compiler support and removes the 'minimal retpoline' option which just
pretended to provide some form of security while providing none"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
x86/speculation: Provide IBPB always command line options
x86/speculation: Add seccomp Spectre v2 user space protection mode
x86/speculation: Enable prctl mode for spectre_v2_user
x86/speculation: Add prctl() control for indirect branch speculation
x86/speculation: Prepare arch_smt_update() for PRCTL mode
x86/speculation: Prevent stale SPEC_CTRL msr content
x86/speculation: Split out TIF update
ptrace: Remove unused ptrace_may_access_sched() and MODE_IBRS
x86/speculation: Prepare for conditional IBPB in switch_mm()
x86/speculation: Avoid __switch_to_xtra() calls
x86/process: Consolidate and simplify switch_to_xtra() code
x86/speculation: Prepare for per task indirect branch speculation control
x86/speculation: Add command line control for indirect branch speculation
x86/speculation: Unify conditional spectre v2 print functions
x86/speculataion: Mark command line parser data __initdata
x86/speculation: Mark string arrays const correctly
x86/speculation: Reorder the spec_v2 code
x86/l1tf: Show actual SMT state
x86/speculation: Rework SMT state change
sched/smt: Expose sched_smt_present static key
...
Do not waste vmalloc space on allocations that do not require a mapping
into the kernel address space.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
By using __dma_direct_alloc_pages we can deal entirely with struct page
instead of having to derive a kernel virtual address.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
The arm64 codebase to implement coherent dma allocation for architectures
with non-coherent DMA is a good start for a generic implementation, given
that is uses the generic remap helpers, provides the atomic pool for
allocations that can't sleep and still is realtively simple and well
tested. Move it to kernel/dma and allow architectures to opt into it
using a config symbol. Architectures just need to provide a new
arch_dma_prep_coherent helper to writeback an invalidate the caches
for any memory that gets remapped for uncached access.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
The dma remap code only makes sense for not cache coherent architectures
(or possibly the corner case of highmem CMA allocations) and currently
is only used by arm, arm64, csky and xtensa. Split it out into a
separate file with a separate Kconfig symbol, which gets the right
copyright notice given that this code was written by Laura Abbott
working for Code Aurora at that point.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
dma_alloc_from_contiguous can return highmem pages depending on the
setup, which a plain non-remapping DMA allocator can't handle. Detect
this case and fail the allocation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Some architectures support remapping highmem into DMA coherent
allocations. To use the common code for them we need variants of
dma_direct_{alloc,free}_pages that do not use kernel virtual addresses.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Often we want to write tests cases that check things like bad context
offset accesses. And one way to do this is to use an odd offset on,
for example, a 32-bit load.
This unfortunately triggers the alignment checks first on platforms
that do not set CONFIG_EFFICIENT_UNALIGNED_ACCESS. So the test
case see the alignment failure rather than what it was testing for.
It is often not completely possible to respect the original intention
of the test, or even test the same exact thing, while solving the
alignment issue.
Another option could have been to check the alignment after the
context and other validations are performed by the verifier, but
that is a non-trivial change to the verifier.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Merge misc fixes from Andrew Morton:
"31 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (31 commits)
ocfs2: fix potential use after free
mm/khugepaged: fix the xas_create_range() error path
mm/khugepaged: collapse_shmem() do not crash on Compound
mm/khugepaged: collapse_shmem() without freezing new_page
mm/khugepaged: minor reorderings in collapse_shmem()
mm/khugepaged: collapse_shmem() remember to clear holes
mm/khugepaged: fix crashes due to misaccounted holes
mm/khugepaged: collapse_shmem() stop if punched or truncated
mm/huge_memory: fix lockdep complaint on 32-bit i_size_read()
mm/huge_memory: splitting set mapping+index before unfreeze
mm/huge_memory: rename freeze_page() to unmap_page()
initramfs: clean old path before creating a hardlink
kernel/kcov.c: mark funcs in __sanitizer_cov_trace_pc() as notrace
psi: make disabling/enabling easier for vendor kernels
proc: fixup map_files test on arm
debugobjects: avoid recursive calls with kmemleak
userfaultfd: shmem: UFFDIO_COPY: set the page dirty if VM_WRITE is not set
userfaultfd: shmem: add i_size checks
userfaultfd: shmem/hugetlbfs: only allow to register VM_MAYWRITE vmas
userfaultfd: shmem: allocate anonymous memory for MAP_PRIVATE shmem
...
- Fix crash by not allowing kprobing of stackleak_erase() (Alexander Popov)
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Merge tag 'gcc-plugins-v4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull stackleak plugin fix from Kees Cook:
"Fix crash by not allowing kprobing of stackleak_erase() (Alexander
Popov)"
* tag 'gcc-plugins-v4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
stackleak: Disable function tracing and kprobes for stackleak_erase()
