When 'kzalloc()' fails in 'snd_hda_attach_pcm_stream()', a new pcm instance is
created without setting its operators via 'snd_pcm_set_ops()'. Following
operations on the new pcm instance can trigger kernel null pointer dereferences
and cause kernel oops.
This bug was found with my work on building a gray-box fault-injection tool for
linux-kernel-module binaries. A kernel null pointer dereference was confirmed
from line 'substream->ops->open()' in function 'snd_pcm_open_substream()' in
file 'sound/core/pcm_native.c'.
This patch fixes the bug by calling 'snd_device_free()' in the error handling
path of 'kzalloc()', which removes the new pcm instance from the snd card before
returns with an error code.
Signed-off-by: Bo Chen <chenbo@pdx.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
net/netfilter/nft_numgen.c:117:1-3: WARNING: PTR_ERR_OR_ZERO can be used
net/netfilter/nft_hash.c:180:1-3: WARNING: PTR_ERR_OR_ZERO can be used
net/netfilter/nft_hash.c:223:1-3: WARNING: PTR_ERR_OR_ZERO can be used
Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR
Generated by: scripts/coccinelle/api/ptr_ret.cocci
Fixes: b9ccc07e3f ("netfilter: nft_hash: add map lookups for hashing operations")
Fixes: d734a28889 ("netfilter: nft_numgen: add map lookups for numgen statements")
CC: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: kbuild test robot <fengguang.wu@intel.com>
Acked-by: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The pmem driver does not honor a forced read-only setting for very long:
$ blockdev --setro /dev/pmem0
$ blockdev --getro /dev/pmem0
1
followed by various commands like these:
$ blockdev --rereadpt /dev/pmem0
or
$ mkfs.ext4 /dev/pmem0
results in this in the kernel serial log:
nd_pmem namespace0.0: region0 read-write, marking pmem0 read-write
with the read-only setting lost:
$ blockdev --getro /dev/pmem0
0
That's from bus.c nvdimm_revalidate_disk(), which always applies the
setting from nd_region (which is initially based on the ACPI NFIT
NVDIMM state flags not_armed bit).
In contrast, commit 20bd1d026a ("scsi: sd: Keep disk read-only when
re-reading partition") fixed this issue for SCSI devices to preserve
the previous setting if it was set to read-only.
This patch modifies bus.c to preserve any previous read-only setting.
It also eliminates the kernel serial log print except for cases where
read-write is changed to read-only, so it doesn't print read-only to
read-only non-changes.
Cc: <stable@vger.kernel.org>
Fixes: 5813882094 ("libnvdimm, nfit: handle unarmed dimms, mark namespaces read-only")
Signed-off-by: Robert Elliott <elliott@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This patch reorders the error cases in showing the XPS configuration so
that we hold off on memory allocation until after we have verified that we
can support XPS on a given ring.
Fixes: 184c449f91 ("net: Add support for XPS with QoS via traffic classes")
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The previous code was optimistic, accepting the offload of whole action
chain when there was a single known action (drop/redirect). This results
in offloading a rule which should not be offloaded, because its behavior
cannot be reproduced in the hardware.
For example:
$ tc filter add dev eno1 parent ffff: protocol ip \
u32 ht 800: order 1 match tcp src 42 FFFF \
action mirred egress mirror dev enp1s16 pipe \
drop
The controller is unable to mirror the packet to a VF, but still
offloads the rule by dropping the packet.
Change the approach of the function to a pessimistic one, rejecting the
chain when an unknown action is found. This is better suited for future
extensions.
Note that both recognized actions always return TC_ACT_SHOT, therefore
it is safe to ignore actions behind them.
Signed-off-by: Ondřej Hlavatý <ohlavaty@redhat.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix to return a negative error code from the failover create fail error
handling case instead of 0, as done elsewhere in this function.
Fixes: ba5e4426e8 ("virtio_net: Extend virtio to use VF datapath when available")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the quest to remove all stack VLA usage from the kernel[1], this
allocates the maximum size expected for all possible types and adds
sanity-checks at both registration and usage to make sure nothing gets
out of sync. This matches the proposed VLA solution for nfnetlink[2]. The
values chosen here were based on finding assignments for .maxtype and
.slave_maxtype and manually counting the enums:
slave_maxtype (max 33):
IFLA_BRPORT_MAX 33
IFLA_BOND_SLAVE_MAX 9
maxtype (max 45):
IFLA_BOND_MAX 28
IFLA_BR_MAX 45
__IFLA_CAIF_HSI_MAX 8
IFLA_CAIF_MAX 4
IFLA_CAN_MAX 16
IFLA_GENEVE_MAX 12
IFLA_GRE_MAX 25
IFLA_GTP_MAX 5
IFLA_HSR_MAX 7
IFLA_IPOIB_MAX 4
IFLA_IPTUN_MAX 21
IFLA_IPVLAN_MAX 3
IFLA_MACSEC_MAX 15
IFLA_MACVLAN_MAX 7
IFLA_PPP_MAX 2
__IFLA_RMNET_MAX 4
IFLA_VLAN_MAX 6
IFLA_VRF_MAX 2
IFLA_VTI_MAX 7
IFLA_VXLAN_MAX 28
VETH_INFO_MAX 2
VXCAN_INFO_MAX 2
This additionally changes maxtype and slave_maxtype fields to unsigned,
since they're only ever using positive values.
[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com
[2] https://patchwork.kernel.org/patch/10439647/
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
By default, sparse assumes a 64bit machine when compiled on x86-64
and 32bit when compiled on anything else.
This can of course create all sort of problems for the other archs, like
issuing false warnings ('shift too big (32) for type unsigned long'), or
worse, failing to emit legitimate warnings.
Fix this by adding the -m32/-m64 flag, depending on CONFIG_64BIT,
to CHECKFLAGS in the main Makefile (and so for all archs).
Also, remove the now unneeded -m32/-m64 in arch specific Makefiles.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
smb2_hdr is just a wrapper around smb2_sync_hdr at this stage
and smb2_hdr is going away.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The two structures smb2_oplock_breaq_req/rsp are now basically identical.
Replace this with a single definition of a smb2_oplock_break structure.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Separate out all the 4 byte rfc1002 headers so that they are no longer
part of the SMB2 header structures to prepare for future work to add
compounding support.
Update the smb3 transform header processing that we no longer have
a rfc1002 header at the start of this structure.
Update smb2_readv_callback to accommodate that the first iovector in the
response is no the smb2 header and no longer a rfc1002 header.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The server detects reconnect by the (non-zero) value in PreviousSessionId
of SMB2/SMB3 SessionSetup request, but this behavior regressed due
to commit 166cea4dc3
("SMB2: Separate RawNTLMSSP authentication from SMB2_sess_setup")
CC: Stable <stable@vger.kernel.org>
CC: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
We need to migrate PR KVM during transaction and userspace will use
kvmppc_get_one_reg_pr()/kvmppc_set_one_reg_pr() APIs to get/set
transaction checkpoint state. This patch adds support for that.
So far, QEMU on PR KVM doesn't fully function for migration but the
savevm/loadvm can be done against a RHEL72 guest. During savevm/
loadvm procedure, the kvm ioctls will be invoked as well.
Test has been performed to savevm/loadvm for a guest running
a HTM test program:
https://github.com/justdoitqd/publicFiles/blob/master/test-tm-mig.c
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
In both HV and PR KVM, the KVM_SET_REGS/KVM_GET_REGS ioctl should
be able to perform without the vcpu loaded.
Since the vcpu mutex locking/unlock has been moved out of vcpu_load()
/vcpu_put(), KVM_SET_REGS/KVM_GET_REGS don't need to do ioctl with
the vcpu loaded anymore. This patch removes vcpu_load()/vcpu_put()
from KVM_SET_REGS/KVM_GET_REGS ioctl.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Since the vcpu mutex locking/unlock has been moved out of vcpu_load()
/vcpu_put(), KVM_GET_ONE_REG and KVM_SET_ONE_REG doesn't need to do
ioctl with loading vcpu anymore. This patch removes vcpu_load()/vcpu_put()
from KVM_GET_ONE_REG and KVM_SET_ONE_REG ioctl.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Although we already have kvm_arch_vcpu_async_ioctl() which doesn't require
ioctl to load vcpu, the sync ioctl code need to be cleaned up when
CONFIG_HAVE_KVM_VCPU_ASYNC_IOCTL is not configured.
This patch moves vcpu_load/vcpu_put down to each ioctl switch case so that
each ioctl can decide to do vcpu_load/vcpu_put or not independently.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently guest kernel doesn't handle TAR facility unavailable and it
always runs with TAR bit on. PR KVM will lazily enable TAR. TAR is not
a frequent-use register and it is not included in SVCPU struct.
Due to the above, the checkpointed TAR val might be a bogus TAR val.
To solve this issue, we will make vcpu->arch.fscr tar bit consistent
with shadow_fscr when TM is enabled.
At the end of emulating treclaim., the correct TAR val need to be loaded
into the register if FSCR_TAR bit is on.
At the beginning of emulating trechkpt., TAR needs to be flushed so that
the right tar val can be copied into tar_tm.
Tested with:
tools/testing/selftests/powerpc/tm/tm-tar
tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar (remove DSCR/PPR
related testing).
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently PR KVM doesn't support transaction memory in guest privileged
state.
This patch adds a check at setting guest msr, so that we can never return
to guest with PR=0 and TS=0b10. A tabort will be emulated to indicate
this and fail transaction immediately.
[paulus@ozlabs.org - don't change the TM_CAUSE_MISC definition, instead
use TM_CAUSE_KVM_FAC_UNAV.]
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently privileged-state guest will be run with TM disabled.
Although the privileged-state guest cannot initiate a new transaction,
it can use tabort to terminate its problem state's transaction.
So it is still necessary to emulate tabort. for privileged-state guest.
Tested with:
https://github.com/justdoitqd/publicFiles/blob/master/test_tabort.c
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This patch adds host emulation when guest PR KVM executes "trechkpt.",
which is a privileged instruction and will trap into host.
We firstly copy vcpu ongoing content into vcpu tm checkpoint
content, then perform kvmppc_restore_tm_pr() to do trechkpt.
with updated vcpu tm checkpoint values.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This patch adds support for "treclaim." emulation when PR KVM guest
executes treclaim. and traps to host.
We will firstly do treclaim. and save TM checkpoint. Then it is
necessary to update vcpu current reg content with checkpointed vals.
When rfid into guest again, those vcpu current reg content (now the
checkpoint vals) will be loaded into regs.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently kvmppc_handle_fac() will not update NV GPRs and thus it can
return with GUEST_RESUME.
However PR KVM guest always disables MSR_TM bit in privileged state.
If PR privileged-state guest is trying to read TM SPRs, it will
trigger TM facility unavailable exception and fall into
kvmppc_handle_fac(). Then the emulation will be done by
kvmppc_core_emulate_mfspr_pr(). The mfspr instruction can include a
RT with NV reg. So it is necessary to restore NV GPRs at this case, to
reflect the update to NV RT.
This patch make kvmppc_handle_fac() return GUEST_RESUME_NV for TM
facility unavailable exceptions in guest privileged state.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently the kernel doesn't use transaction memory.
And there is an issue for privileged state in the guest that:
tbegin/tsuspend/tresume/tabort TM instructions can impact MSR TM bits
without trapping into the PR host. So following code will lead to a
false mfmsr result:
tbegin <- MSR bits update to Transaction active.
beq <- failover handler branch
mfmsr <- still read MSR bits from magic page with
transaction inactive.
It is not an issue for non-privileged guest state since its mfmsr is
not patched with magic page and will always trap into the PR host.
This patch will always fail tbegin attempt for privileged state in the
guest, so that the above issue is prevented. It is benign since
currently (guest) kernel doesn't initiate a transaction.
Test case:
https://github.com/justdoitqd/publicFiles/blob/master/test_tbegin_pr.c
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The mfspr/mtspr on TM SPRs(TEXASR/TFIAR/TFHAR) are non-privileged
instructions and can be executed by PR KVM guest in problem state
without trapping into the host. We only emulate mtspr/mfspr
texasr/tfiar/tfhar in guest PR=0 state.
When we are emulating mtspr tm sprs in guest PR=0 state, the emulation
result needs to be visible to guest PR=1 state. That is, the actual TM
SPR val should be loaded into actual registers.
We already flush TM SPRs into vcpu when switching out of CPU, and load
TM SPRs when switching back.
This patch corrects mfspr()/mtspr() emulation for TM SPRs to make the
actual source/dest be the actual TM SPRs.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The math registers will be saved into vcpu->arch.fp/vr and corresponding
vcpu->arch.fp_tm/vr_tm area.
We flush or giveup the math regs into vcpu->arch.fp/vr before saving
transaction. After transaction is restored, the math regs will be loaded
back into regs.
If there is a FP/VEC/VSX unavailable exception during transaction active
state, the math checkpoint content might be incorrect and we need to do
treclaim./load the correct checkpoint val/trechkpt. sequence to retry the
transaction. That will make our solution complicated. To solve this issue,
we always make the hardware guest MSR math bits (shadow_msr) consistent
with the MSR val which guest sees (kvmppc_get_msr()) when guest msr is
with tm enabled. Then all FP/VEC/VSX unavailable exception can be delivered
to guest and guest handles the exception by itself.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The transaction memory checkpoint area save/restore behavior is
triggered when VCPU qemu process is switching out/into CPU, i.e.
at kvmppc_core_vcpu_put_pr() and kvmppc_core_vcpu_load_pr().
MSR TM active state is determined by TS bits:
active: 10(transactional) or 01 (suspended)
inactive: 00 (non-transactional)
We don't "fake" TM functionality for guest. We "sync" guest virtual
MSR TM active state(10 or 01) with shadow MSR. That is to say,
we don't emulate a transactional guest with a TM inactive MSR.
TM SPR support(TFIAR/TFAR/TEXASR) has already been supported by
commit 9916d57e64 ("KVM: PPC: Book3S PR: Expose TM registers").
Math register support (FPR/VMX/VSX) will be done at subsequent
patch.
Whether TM context need to be saved/restored can be determined
by kvmppc_get_msr() TM active state:
* TM active - save/restore TM context
* TM inactive - no need to do so and only save/restore
TM SPRs.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Suggested-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This patch adds 2 new APIs, kvmppc_save_tm_sprs() and
kvmppc_restore_tm_sprs(), for the purpose of TEXASR/TFIAR/TFHAR
save/restore.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This patch adds 2 new APIs: kvmppc_copyto_vcpu_tm() and
kvmppc_copyfrom_vcpu_tm(). These 2 APIs will be used to copy from/to TM
data between VCPU_TM/VCPU area.
PR KVM will use these APIs for treclaim. or trechkpt. emulation.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
PR KVM host usually runs with TM enabled in its host MSR value, and
with non-transactional TS value.
When a guest with TM active traps into PR KVM host, the rfid at the
tail of kvmppc_interrupt_pr() will try to switch TS bits from
S0 (Suspended & TM disabled) to N1 (Non-transactional & TM enabled).
That will leads to TM Bad Thing interrupt.
This patch manually sets target TS bits unchanged to avoid this
exception.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
According to ISA specification for RFID, in MSR TM disabled and TS
suspended state (S0), if the target MSR is TM disabled and TS state is
inactive (N0), rfid should suppress this update.
This patch makes the RFID emulation of PR KVM consistent with this.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
MSR TS bits can be modified with non-privileged instruction such as
tbegin./tend. That means guest can change MSR value "silently" without
notifying host.
It is necessary to sync the TM bits to host so that host can calculate
shadow msr correctly.
Note, privileged mode in the guest will always fail transactions so we
only take care of problem state mode in the guest.
The logic is put into kvmppc_copy_from_svcpu() so that
kvmppc_handle_exit_pr() can use correct MSR TM bits even when preemption
occurs.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
PowerPC TM functionality needs MSR TM/TS bits support in hardware level.
Guest TM functionality can not be emulated with "fake" MSR (msr in magic
page) TS bits.
This patch syncs TM/TS bits in shadow_msr with the MSR value in magic
page, so that the MSR TS value which guest sees is consistent with actual
MSR bits running in guest.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This patch simulates interrupt behavior per Power ISA while injecting
interrupt in PR KVM:
- When interrupt happens, transactional state should be suspended.
kvmppc_mmu_book3s_64_reset_msr() will be invoked when injecting an
interrupt. This patch performs this ISA logic in
kvmppc_mmu_book3s_64_reset_msr().
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently __kvmppc_save/restore_tm() APIs can only be invoked from
assembly function. This patch adds C function wrappers for them so
that they can be safely called from C function.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
kvmppc_save_tm() invokes store_fp_state/store_vr_state(). So it is
mandatory to turn on FP/VSX/VMX MSR bits for its execution, just
like what kvmppc_restore_tm() did.
Previously HV KVM has turned the bits on outside of function
kvmppc_save_tm(). Now we include this bit change in kvmppc_save_tm()
so that the logic is cleaner. And PR KVM can reuse it later.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
HV KVM and PR KVM need different MSR source to indicate whether
treclaim. or trecheckpoint. is necessary.
This patch add new parameter (guest MSR) for these kvmppc_save_tm/
kvmppc_restore_tm() APIs:
- For HV KVM, it is VCPU_MSR
- For PR KVM, it is current host MSR or VCPU_SHADOW_SRR1
This enhancement enables these 2 APIs to be reused by PR KVM later.
And the patch keeps HV KVM logic unchanged.
This patch also reworks kvmppc_save_tm()/kvmppc_restore_tm() to
have a clean ABI: r3 for vcpu and r4 for guest_msr.
During kvmppc_save_tm/kvmppc_restore_tm(), the R1 need to be saved
or restored. Currently the R1 is saved into HSTATE_HOST_R1. In PR
KVM, we are going to add a C function wrapper for
kvmppc_save_tm/kvmppc_restore_tm() where the R1 will be incremented
with added stackframe and save into HSTATE_HOST_R1. There are several
places in HV KVM to load HSTATE_HOST_R1 as R1, and we don't want to
bring risk or confusion by TM code.
This patch will use HSTATE_SCRATCH2 to save/restore R1 in
kvmppc_save_tm/kvmppc_restore_tm() to avoid future confusion, since
the r1 is actually a temporary/scratch value to be saved/stored.
[paulus@ozlabs.org - rebased on top of 7b0e827c69 ("KVM: PPC: Book3S HV:
Factor fake-suspend handling out of kvmppc_save/restore_tm", 2018-05-30)]
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This adds wrappers for the __builtin overflow checkers present in gcc
5.1+ as well as fallback implementations for earlier compilers. It's not
that easy to implement the fully generic __builtin_X_overflow(T1 a, T2
b, T3 *d) in macros, so the fallback code assumes that T1, T2 and T3 are
the same. We obviously don't want the wrappers to have different
semantics depending on $GCC_VERSION, so we also insist on that even when
using the builtins.
There are a few problems with the 'a+b < a' idiom for checking for
overflow: For signed types, it relies on undefined behaviour and is
not actually complete (it doesn't check underflow;
e.g. INT_MIN+INT_MIN == 0 isn't caught). Due to type promotion it
is wrong for all types (signed and unsigned) narrower than
int. Similarly, when a and b does not have the same type, there are
subtle cases like
u32 a;
if (a + sizeof(foo) < a)
return -EOVERFLOW;
a += sizeof(foo);
where the test is always false on 64 bit platforms. Add to that that it
is not always possible to determine the types involved at a glance.
The new overflow.h is somewhat bulky, but that's mostly a result of
trying to be type-generic, complete (e.g. catching not only overflow
but also signed underflow) and not relying on undefined behaviour.
Linus is of course right [1] that for unsigned subtraction a-b, the
right way to check for overflow (underflow) is "b > a" and not
"__builtin_sub_overflow(a, b, &d)", but that's just one out of six cases
covered here, and included mostly for completeness.
So is it worth it? I think it is, if nothing else for the documentation
value of seeing
if (check_add_overflow(a, b, &d))
return -EGOAWAY;
do_stuff_with(d);
instead of the open-coded (and possibly wrong and/or incomplete and/or
UBsan-tickling)
if (a+b < a)
return -EGOAWAY;
do_stuff_with(a+b);
While gcc does recognize the 'a+b < a' idiom for testing unsigned add
overflow, it doesn't do nearly as good for unsigned multiplication
(there's also no single well-established idiom). So using
check_mul_overflow in kcalloc and friends may also make gcc generate
slightly better code.
[1] https://lkml.org/lkml/2015/11/2/658
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Kees Cook <keescook@chromium.org>
Prevent speculation at the syscall table decoding by clamping the index
used to zero on invalid system call numbers, and using the csdb
speculative barrier.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Add an implementation of the array_index_mask_nospec() function for
mitigating Spectre variant 1 throughout the kernel.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Add assembly and C macros for the new CSDB instruction.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
- Clear out i_mapping error state when we're reinitializing inodes.
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Merge tag 'xfs-4.17-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fix from Darrick Wong:
"Clear out i_mapping error state when we're reinitializing inodes.
This last minute fix prevents writeback error state from persisting
past the end of the in-core inode lifecycle and causing EIO errors to
be reported to userspace when no error has occurred.
This fix for the behavioral regression has been soaking in for-next
for a while, but various fs developers persuaded me to try to get it
upstream for 4.17 because the patch that broke things was introduced
in 4.17-rc4"
* tag 'xfs-4.17-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
fs: clear writeback errors in inode_init_always
The added Centriq support broke compilation with CONFIG_ACPI disabled:
drivers/i2c/busses/i2c-qup.c: In function 'qup_i2c_probe':
drivers/i2c/busses/i2c-qup.c:1707:25: error: 'qup_i2c_acpi_match' undeclared (first use in this function); did you mean 'qup_i2c_recv_data'?
This fixes it by removing the extraneous #ifdef. All ACPI specific
code will be dropped implicitly when that option is disabled, but
the compiler first needs to see it.
Fixes: 902a91a02b ("i2c: qup: add probe path for Centriq ACPI devices")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Now that alarms are emulated, remove the irq sysfs file that could be used
to send alarms.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Use timers to emulate alarms. Note that multiple alarms may happen if they
are set more than 15 days after the current RTC time.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Store the time as an offset to system time. As the offset is in second, it
is currently always synced with system time.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The rtc proc callback is useless for two reasosn:
- the test RTC is often not the first RTC so it will never be used
- all the info is available in the name file of the RTC sys folder
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
