Commit graph

1072589 commits

Author SHA1 Message Date
Paul E. McKenney
da123016ca rcu-tasks: Fix computation of CPU-to-list shift counts
The ->percpu_enqueue_shift field is used to map from the running CPU
number to the index of the corresponding callback list.  This mapping
can change at runtime in response to varying callback load, resulting
in varying levels of contention on the callback-list locks.

Unfortunately, the initial value of this field is correct only if the
system happens to have a power-of-two number of CPUs, otherwise the
callbacks from the high-numbered CPUs can be placed into the callback list
indexed by 1 (rather than 0), and those index-1 callbacks will be ignored.
This can result in soft lockups and hangs.

This commit therefore corrects this mapping, adding one to this shift
count as needed for systems having odd numbers of CPUs.

Fixes: 7a30871b6a ("rcu-tasks: Introduce ->percpu_enqueue_shift for dynamic queue selection")
Reported-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Reported-by: Martin Lau <kafai@fb.com>
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-01-26 13:04:05 -08:00
Jeff Layton
4584a768f2 ceph: set pool_ns in new inode layout for async creates
Dan reported that he was unable to write to files that had been
asynchronously created when the client's OSD caps are restricted to a
particular namespace.

The issue is that the layout for the new inode is only partially being
filled. Ensure that we populate the pool_ns_data and pool_ns_len in the
iinfo before calling ceph_fill_inode.

Cc: stable@vger.kernel.org
URL: https://tracker.ceph.com/issues/54013
Fixes: 9a8d03ca2e ("ceph: attempt to do async create when possible")
Reported-by: Dan van der Ster <dan@vanderster.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2022-01-26 20:17:50 +01:00
Jeff Layton
932a9b5870 ceph: properly put ceph_string reference after async create attempt
The reference acquired by try_prep_async_create is currently leaked.
Ensure we put it.

Cc: stable@vger.kernel.org
Fixes: 9a8d03ca2e ("ceph: attempt to do async create when possible")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2022-01-26 20:17:50 +01:00
Xiubo Li
89d43d0551 ceph: put the requests/sessions when it fails to alloc memory
When failing to allocate the sessions memory we should make sure
the req1 and req2 and the sessions get put. And also in case the
max_sessions decreased so when kreallocate the new memory some
sessions maybe missed being put.

And if the max_sessions is 0 krealloc will return ZERO_SIZE_PTR,
which will lead to a distinct access fault.

URL: https://tracker.ceph.com/issues/53819
Fixes: e1a4541ec0 ("ceph: flush the mdlog before waiting on unsafe reqs")
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2022-01-26 20:17:50 +01:00
Evgenii Stepanov
3758a6c74e arm64: extable: fix load_unaligned_zeropad() reg indices
In ex_handler_load_unaligned_zeropad() we erroneously extract the data and
addr register indices from ex->type rather than ex->data. As ex->type will
contain EX_TYPE_LOAD_UNALIGNED_ZEROPAD (i.e. 4):
 * We'll always treat X0 as the address register, since EX_DATA_REG_ADDR is
   extracted from bits [9:5]. Thus, we may attempt to dereference an
   arbitrary address as X0 may hold an arbitrary value.
 * We'll always treat X4 as the data register, since EX_DATA_REG_DATA is
   extracted from bits [4:0]. Thus we will corrupt X4 and cause arbitrary
   behaviour within load_unaligned_zeropad() and its caller.

Fix this by extracting both values from ex->data as originally intended.

On an MTE-enabled QEMU image we are hitting the following crash:
 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
 Call trace:
  fixup_exception+0xc4/0x108
  __do_kernel_fault+0x3c/0x268
  do_tag_check_fault+0x3c/0x104
  do_mem_abort+0x44/0xf4
  el1_abort+0x40/0x64
  el1h_64_sync_handler+0x60/0xa0
  el1h_64_sync+0x7c/0x80
  link_path_walk+0x150/0x344
  path_openat+0xa0/0x7dc
  do_filp_open+0xb8/0x168
  do_sys_openat2+0x88/0x17c
  __arm64_sys_openat+0x74/0xa0
  invoke_syscall+0x48/0x148
  el0_svc_common+0xb8/0xf8
  do_el0_svc+0x28/0x88
  el0_svc+0x24/0x84
  el0t_64_sync_handler+0x88/0xec
  el0t_64_sync+0x1b4/0x1b8
 Code: f8695a69 71007d1f 540000e0 927df12a (f940014a)

Fixes: 753b323687 ("arm64: extable: add load_unaligned_zeropad() handler")
Cc: <stable@vger.kernel.org> # 5.16.x
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Evgenii Stepanov <eugenis@google.com>
Link: https://lore.kernel.org/r/20220125182217.2605202-1-eugenis@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-01-26 18:58:12 +00:00
Dan Carpenter
fc55e63e14 counter: fix an IS_ERR() vs NULL bug
There are 8 callers for devm_counter_alloc() and they all check for NULL
instead of error pointers.  I think NULL is the better thing to return
for allocation functions so update counter_alloc() and devm_counter_alloc()
to return NULL instead of error pointers.

Fixes: c18e276030 ("counter: Provide alternative counter registration functions")
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220111173243.GA2192@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-26 19:40:33 +01:00
Paolo Bonzini
dd4516aee3 selftests: kvm: move vm_xsave_req_perm call to amx_test
There is no need for tests other than amx_test to enable dynamic xsave
states.  Remove the call to vm_xsave_req_perm from generic code,
and move it inside the test.  While at it, allow customizing the bit
that is requested, so that future tests can use it differently.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:45:20 -05:00
Like Xu
05a9e06505 KVM: x86: Sync the states size with the XCR0/IA32_XSS at, any time
XCR0 is reset to 1 by RESET but not INIT and IA32_XSS is zeroed by
both RESET and INIT. The kvm_set_msr_common()'s handling of MSR_IA32_XSS
also needs to update kvm_update_cpuid_runtime(). In the above cases, the
size in bytes of the XSAVE area containing all states enabled by XCR0 or
(XCRO | IA32_XSS) needs to be updated.

For simplicity and consistency, existing helpers are used to write values
and call kvm_update_cpuid_runtime(), and it's not exactly a fast path.

Fixes: a554d207dc ("KVM: X86: Processor States following Reset or INIT")
Cc: stable@vger.kernel.org
Signed-off-by: Like Xu <likexu@tencent.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220126172226.2298529-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:42:45 -05:00
Like Xu
4c282e51e4 KVM: x86: Update vCPU's runtime CPUID on write to MSR_IA32_XSS
Do a runtime CPUID update for a vCPU if MSR_IA32_XSS is written, as the
size in bytes of the XSAVE area is affected by the states enabled in XSS.

Fixes: 203000993d ("kvm: vmx: add MSR logic for XSAVES")
Cc: stable@vger.kernel.org
Signed-off-by: Like Xu <likexu@tencent.com>
[sean: split out as a separate patch, adjust Fixes tag]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220126172226.2298529-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:42:45 -05:00
Xiaoyao Li
be4f3b3f82 KVM: x86: Keep MSR_IA32_XSS unchanged for INIT
It has been corrected from SDM version 075 that MSR_IA32_XSS is reset to
zero on Power up and Reset but keeps unchanged on INIT.

Fixes: a554d207dc ("KVM: X86: Processor States following Reset or INIT")
Cc: stable@vger.kernel.org
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220126172226.2298529-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:42:44 -05:00
Vasily Gorbik
663d34c8df s390/hypfs: include z/VM guests with access control group set
Currently if z/VM guest is allowed to retrieve hypervisor performance
data globally for all guests (privilege class B) the query is formed in a
way to include all guests but the group name is left empty. This leads to
that z/VM guests which have access control group set not being included
in the results (even local vm).

Change the query group identifier from empty to "any" to retrieve
information about all guests from any groups (or without a group set).

Cc: stable@vger.kernel.org
Fixes: 31cb4bd31a ("[S390] Hypervisor filesystem (s390_hypfs) for z/VM")
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-01-26 18:42:39 +01:00
Sean Christopherson
811f95ff95 KVM: x86: Free kvm_cpuid_entry2 array on post-KVM_RUN KVM_SET_CPUID{,2}
Free the "struct kvm_cpuid_entry2" array on successful post-KVM_RUN
KVM_SET_CPUID{,2} to fix a memory leak, the callers of kvm_set_cpuid()
free the array only on failure.

 BUG: memory leak
 unreferenced object 0xffff88810963a800 (size 2048):
  comm "syz-executor025", pid 3610, jiffies 4294944928 (age 8.080s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 0d 00 00 00  ................
    47 65 6e 75 6e 74 65 6c 69 6e 65 49 00 00 00 00  GenuntelineI....
  backtrace:
    [<ffffffff814948ee>] kmalloc_node include/linux/slab.h:604 [inline]
    [<ffffffff814948ee>] kvmalloc_node+0x3e/0x100 mm/util.c:580
    [<ffffffff814950f2>] kvmalloc include/linux/slab.h:732 [inline]
    [<ffffffff814950f2>] vmemdup_user+0x22/0x100 mm/util.c:199
    [<ffffffff8109f5ff>] kvm_vcpu_ioctl_set_cpuid2+0x8f/0xf0 arch/x86/kvm/cpuid.c:423
    [<ffffffff810711b9>] kvm_arch_vcpu_ioctl+0xb99/0x1e60 arch/x86/kvm/x86.c:5251
    [<ffffffff8103e92d>] kvm_vcpu_ioctl+0x4ad/0x950 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4066
    [<ffffffff815afacc>] vfs_ioctl fs/ioctl.c:51 [inline]
    [<ffffffff815afacc>] __do_sys_ioctl fs/ioctl.c:874 [inline]
    [<ffffffff815afacc>] __se_sys_ioctl fs/ioctl.c:860 [inline]
    [<ffffffff815afacc>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:860
    [<ffffffff844a3335>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff844a3335>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84600068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

Fixes: c6617c61e8 ("KVM: x86: Partially allow KVM_SET_CPUID{,2} after KVM_RUN")
Cc: stable@vger.kernel.org
Reported-by: syzbot+be576ad7655690586eec@syzkaller.appspotmail.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220125210445.2053429-1-seanjc@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:42:31 -05:00
Sean Christopherson
d6e656cd26 KVM: nVMX: WARN on any attempt to allocate shadow VMCS for vmcs02
WARN if KVM attempts to allocate a shadow VMCS for vmcs02.  KVM emulates
VMCS shadowing but doesn't virtualize it, i.e. KVM should never allocate
a "real" shadow VMCS for L2.

The previous code WARNed but continued anyway with the allocation,
presumably in an attempt to avoid NULL pointer dereference.
However, alloc_vmcs (and hence alloc_shadow_vmcs) can fail, and
indeed the sole caller does:

	if (enable_shadow_vmcs && !alloc_shadow_vmcs(vcpu))
		goto out_shadow_vmcs;

which makes it not a useful attempt.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220125220527.2093146-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:04 -05:00
Sean Christopherson
4cf3d3ebe8 KVM: selftests: Don't skip L2's VMCALL in SMM test for SVM guest
Don't skip the vmcall() in l2_guest_code() prior to re-entering L2, doing
so will result in L2 running to completion, popping '0' off the stack for
RET, jumping to address '0', and ultimately dying with a triple fault
shutdown.

It's not at all obvious why the test re-enters L2 and re-executes VMCALL,
but presumably it serves a purpose.  The VMX path doesn't skip vmcall(),
and the test can't possibly have passed on SVM, so just do what VMX does.

Fixes: d951b2210c ("KVM: selftests: smm_test: Test SMM enter from L2")
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220125221725.2101126-1-seanjc@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:04 -05:00
Vitaly Kuznetsov
033a3ea59a KVM: x86: Check .flags in kvm_cpuid_check_equal() too
kvm_cpuid_check_equal() checks for the (full) equality of the supplied
CPUID data so .flags need to be checked too.

Reported-by: Sean Christopherson <seanjc@google.com>
Fixes: c6617c61e8 ("KVM: x86: Partially allow KVM_SET_CPUID{,2} after KVM_RUN")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220126131804.2839410-1-vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:03 -05:00
Sean Christopherson
f7e570780e KVM: x86: Forcibly leave nested virt when SMM state is toggled
Forcibly leave nested virtualization operation if userspace toggles SMM
state via KVM_SET_VCPU_EVENTS or KVM_SYNC_X86_EVENTS.  If userspace
forces the vCPU out of SMM while it's post-VMXON and then injects an SMI,
vmx_enter_smm() will overwrite vmx->nested.smm.vmxon and end up with both
vmxon=false and smm.vmxon=false, but all other nVMX state allocated.

Don't attempt to gracefully handle the transition as (a) most transitions
are nonsencial, e.g. forcing SMM while L2 is running, (b) there isn't
sufficient information to handle all transitions, e.g. SVM wants access
to the SMRAM save state, and (c) KVM_SET_VCPU_EVENTS must precede
KVM_SET_NESTED_STATE during state restore as the latter disallows putting
the vCPU into L2 if SMM is active, and disallows tagging the vCPU as
being post-VMXON in SMM if SMM is not active.

Abuse of KVM_SET_VCPU_EVENTS manifests as a WARN and memory leak in nVMX
due to failure to free vmcs01's shadow VMCS, but the bug goes far beyond
just a memory leak, e.g. toggling SMM on while L2 is active puts the vCPU
in an architecturally impossible state.

  WARNING: CPU: 0 PID: 3606 at free_loaded_vmcs arch/x86/kvm/vmx/vmx.c:2665 [inline]
  WARNING: CPU: 0 PID: 3606 at free_loaded_vmcs+0x158/0x1a0 arch/x86/kvm/vmx/vmx.c:2656
  Modules linked in:
  CPU: 1 PID: 3606 Comm: syz-executor725 Not tainted 5.17.0-rc1-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  RIP: 0010:free_loaded_vmcs arch/x86/kvm/vmx/vmx.c:2665 [inline]
  RIP: 0010:free_loaded_vmcs+0x158/0x1a0 arch/x86/kvm/vmx/vmx.c:2656
  Code: <0f> 0b eb b3 e8 8f 4d 9f 00 e9 f7 fe ff ff 48 89 df e8 92 4d 9f 00
  Call Trace:
   <TASK>
   kvm_arch_vcpu_destroy+0x72/0x2f0 arch/x86/kvm/x86.c:11123
   kvm_vcpu_destroy arch/x86/kvm/../../../virt/kvm/kvm_main.c:441 [inline]
   kvm_destroy_vcpus+0x11f/0x290 arch/x86/kvm/../../../virt/kvm/kvm_main.c:460
   kvm_free_vcpus arch/x86/kvm/x86.c:11564 [inline]
   kvm_arch_destroy_vm+0x2e8/0x470 arch/x86/kvm/x86.c:11676
   kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1217 [inline]
   kvm_put_kvm+0x4fa/0xb00 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1250
   kvm_vm_release+0x3f/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1273
   __fput+0x286/0x9f0 fs/file_table.c:311
   task_work_run+0xdd/0x1a0 kernel/task_work.c:164
   exit_task_work include/linux/task_work.h:32 [inline]
   do_exit+0xb29/0x2a30 kernel/exit.c:806
   do_group_exit+0xd2/0x2f0 kernel/exit.c:935
   get_signal+0x4b0/0x28c0 kernel/signal.c:2862
   arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868
   handle_signal_work kernel/entry/common.c:148 [inline]
   exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
   exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207
   __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
   syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
   do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
   entry_SYSCALL_64_after_hwframe+0x44/0xae
   </TASK>

Cc: stable@vger.kernel.org
Reported-by: syzbot+8112db3ab20e70d50c31@syzkaller.appspotmail.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220125220358.2091737-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:03 -05:00
Vitaly Kuznetsov
aa3b39f38c KVM: SVM: drop unnecessary code in svm_hv_vmcb_dirty_nested_enlightenments()
Commit 3fa5e8fd0a ("KVM: SVM: delay svm_vcpu_init_msrpm after
svm->vmcb is initialized") re-arranged svm_vcpu_init_msrpm() call in
svm_create_vcpu(), thus making the comment about vmcb being NULL
obsolete. Drop it.

While on it, drop superfluous vmcb_is_clean() check: vmcb_mark_dirty()
is a bit flip, an extra check is unlikely to bring any performance gain.
Drop now-unneeded vmcb_is_clean() helper as well.

Fixes: 3fa5e8fd0a ("KVM: SVM: delay svm_vcpu_init_msrpm after svm->vmcb is initialized")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211220152139.418372-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:03 -05:00
Vitaly Kuznetsov
38dfa8308c KVM: SVM: hyper-v: Enable Enlightened MSR-Bitmap support for real
Commit c4327f15df ("KVM: SVM: hyper-v: Enlightened MSR-Bitmap support")
introduced enlightened MSR-Bitmap support for KVM-on-Hyper-V but it didn't
actually enable the support. Similar to enlightened NPT TLB flush and
direct TLB flush features, the guest (KVM) has to tell L0 (Hyper-V) that
it's using the feature by setting the appropriate feature fit in VMCB
control area (sw reserved fields).

Fixes: c4327f15df ("KVM: SVM: hyper-v: Enlightened MSR-Bitmap support")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211220152139.418372-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:02 -05:00
Sean Christopherson
cdf85e0c5d KVM: SVM: Don't kill SEV guest if SMAP erratum triggers in usermode
Inject a #GP instead of synthesizing triple fault to try to avoid killing
the guest if emulation of an SEV guest fails due to encountering the SMAP
erratum.  The injected #GP may still be fatal to the guest, e.g. if the
userspace process is providing critical functionality, but KVM should
make every attempt to keep the guest alive.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Message-Id: <20220120010719.711476-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:02 -05:00
Sean Christopherson
3280cc22ae KVM: SVM: Don't apply SEV+SMAP workaround on code fetch or PT access
Resume the guest instead of synthesizing a triple fault shutdown if the
instruction bytes buffer is empty due to the #NPF being on the code fetch
itself or on a page table access.  The SMAP errata applies if and only if
the code fetch was successful and ucode's subsequent data read from the
code page encountered a SMAP violation.  In practice, the guest is likely
hosed either way, but crashing the guest on a code fetch to emulated MMIO
is technically wrong according to the behavior described in the APM.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Message-Id: <20220120010719.711476-9-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:01 -05:00
Sean Christopherson
04c40f344d KVM: SVM: Inject #UD on attempted emulation for SEV guest w/o insn buffer
Inject #UD if KVM attempts emulation for an SEV guests without an insn
buffer and instruction decoding is required.  The previous behavior of
allowing emulation if there is no insn buffer is undesirable as doing so
means KVM is reading guest private memory and thus decoding cyphertext,
i.e. is emulating garbage.  The check was previously necessary as the
emulation type was not provided, i.e. SVM needed to allow emulation to
handle completion of emulation after exiting to userspace to handle I/O.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Message-Id: <20220120010719.711476-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:01 -05:00
Sean Christopherson
132627c64d KVM: SVM: WARN if KVM attempts emulation on #UD or #GP for SEV guests
WARN if KVM attempts to emulate in response to #UD or #GP for SEV guests,
i.e. if KVM intercepts #UD or #GP, as emulation on any fault except #NPF
is impossible since KVM cannot read guest private memory to get the code
stream, and the CPU's DecodeAssists feature only provides the instruction
bytes on #NPF.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Message-Id: <20220120010719.711476-7-seanjc@google.com>
[Warn on EMULTYPE_TRAP_UD_FORCED according to Liam Merwick's review. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:01 -05:00
Sean Christopherson
4d31d9eff2 KVM: x86: Pass emulation type to can_emulate_instruction()
Pass the emulation type to kvm_x86_ops.can_emulate_insutrction() so that
a future commit can harden KVM's SEV support to WARN on emulation
scenarios that should never happen.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Message-Id: <20220120010719.711476-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:00 -05:00
Sean Christopherson
c532f2903b KVM: SVM: Explicitly require DECODEASSISTS to enable SEV support
Add a sanity check on DECODEASSIST being support if SEV is supported, as
KVM cannot read guest private memory and thus relies on the CPU to
provide the instruction byte stream on #NPF for emulation.  The intent of
the check is to document the dependency, it should never fail in practice
as producing hardware that supports SEV but not DECODEASSISTS would be
non-sensical.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Message-Id: <20220120010719.711476-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:00 -05:00
Sean Christopherson
0b0be065b7 KVM: SVM: Don't intercept #GP for SEV guests
Never intercept #GP for SEV guests as reading SEV guest private memory
will return cyphertext, i.e. emulating on #GP can't work as intended.

Cc: stable@vger.kernel.org
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Message-Id: <20220120010719.711476-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:15:00 -05:00
Sean Christopherson
31c2558569 Revert "KVM: SVM: avoid infinite loop on NPF from bad address"
Revert a completely broken check on an "invalid" RIP in SVM's workaround
for the DecodeAssists SMAP errata.  kvm_vcpu_gfn_to_memslot() obviously
expects a gfn, i.e. operates in the guest physical address space, whereas
RIP is a virtual (not even linear) address.  The "fix" worked for the
problematic KVM selftest because the test identity mapped RIP.

Fully revert the hack instead of trying to translate RIP to a GPA, as the
non-SEV case is now handled earlier, and KVM cannot access guest page
tables to translate RIP.

This reverts commit e72436bc3a.

Fixes: e72436bc3a ("KVM: SVM: avoid infinite loop on NPF from bad address")
Reported-by: Liam Merwick <liam.merwick@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Message-Id: <20220120010719.711476-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:14:59 -05:00
Sean Christopherson
55467fcd55 KVM: SVM: Never reject emulation due to SMAP errata for !SEV guests
Always signal that emulation is possible for !SEV guests regardless of
whether or not the CPU provided a valid instruction byte stream.  KVM can
read all guest state (memory and registers) for !SEV guests, i.e. can
fetch the code stream from memory even if the CPU failed to do so because
of the SMAP errata.

Fixes: 05d5a48635 ("KVM: SVM: Workaround errata#1096 (insn_len maybe zero on SMAP violation)")
Cc: stable@vger.kernel.org
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Message-Id: <20220120010719.711476-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:14:59 -05:00
Denis Valeev
47c28d436f KVM: x86: nSVM: skip eax alignment check for non-SVM instructions
The bug occurs on #GP triggered by VMware backdoor when eax value is
unaligned. eax alignment check should not be applied to non-SVM
instructions because it leads to incorrect omission of the instructions
emulation.
Apply the alignment check only to SVM instructions to fix.

Fixes: d1cba6c922 ("KVM: x86: nSVM: test eax for 4K alignment for GP errata workaround")
Signed-off-by: Denis Valeev <lemniscattaden@gmail.com>
Message-Id: <Yexlhaoe1Fscm59u@q>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:14:59 -05:00
Like Xu
1ffce0924a KVM: x86/cpuid: Exclude unpermitted xfeatures sizes at KVM_GET_SUPPORTED_CPUID
With the help of xstate_get_guest_group_perm(), KVM can exclude unpermitted
xfeatures in cpuid.0xd.0.eax, in which case the corresponding xfeatures
sizes should also be matched to the permitted xfeatures.

To fix this inconsistency, the permitted_xcr0 and permitted_xss are defined
consistently, which implies 'supported' plus certain permissions for this
task, and it also fixes cpuid.0xd.1.ebx and later leaf-by-leaf queries.

Fixes: 445ecdf79b ("kvm: x86: Exclude unpermitted xfeatures at KVM_GET_SUPPORTED_CPUID")
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220125115223.33707-1-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:14:58 -05:00
Wanpeng Li
35fe7cfbab KVM: LAPIC: Also cancel preemption timer during SET_LAPIC
The below warning is splatting during guest reboot.

  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1931 at arch/x86/kvm/x86.c:10322 kvm_arch_vcpu_ioctl_run+0x874/0x880 [kvm]
  CPU: 0 PID: 1931 Comm: qemu-system-x86 Tainted: G          I       5.17.0-rc1+ #5
  RIP: 0010:kvm_arch_vcpu_ioctl_run+0x874/0x880 [kvm]
  Call Trace:
   <TASK>
   kvm_vcpu_ioctl+0x279/0x710 [kvm]
   __x64_sys_ioctl+0x83/0xb0
   do_syscall_64+0x3b/0xc0
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7fd39797350b

This can be triggered by not exposing tsc-deadline mode and doing a reboot in
the guest. The lapic_shutdown() function which is called in sys_reboot path
will not disarm the flying timer, it just masks LVTT. lapic_shutdown() clears
APIC state w/ LVT_MASKED and timer-mode bit is 0, this can trigger timer-mode
switch between tsc-deadline and oneshot/periodic, which can result in preemption
timer be cancelled in apic_update_lvtt(). However, We can't depend on this when
not exposing tsc-deadline mode and oneshot/periodic modes emulated by preemption
timer. Qemu will synchronise states around reset, let's cancel preemption timer
under KVM_SET_LAPIC.

Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1643102220-35667-1-git-send-email-wanpengli@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:14:58 -05:00
Jim Mattson
519669cc58 KVM: VMX: Remove vmcs_config.order
The maximum size of a VMCS (or VMXON region) is 4096. By definition,
these are order 0 allocations.

Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20220125004359.147600-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26 12:14:58 -05:00
Bjorn Helgaas
66d28b21fe PCI/sysfs: Find shadow ROM before static attribute initialization
Ville reported that the sysfs "rom" file for VGA devices disappeared after
527139d738 ("PCI/sysfs: Convert "rom" to static attribute").

Prior to 527139d738, FINAL fixups, including pci_fixup_video() where we
find shadow ROMs, were run before pci_create_sysfs_dev_files() created the
sysfs "rom" file.

After 527139d738, "rom" is a static attribute and is created before FINAL
fixups are run, so we didn't create "rom" files for shadow ROMs:

  acpi_pci_root_add
    ...
      pci_scan_single_device
        pci_device_add
          pci_fixup_video                    # <-- new HEADER fixup
          device_add
            ...
              if (grp->is_visible())
                pci_dev_rom_attr_is_visible  # after 527139d738
    pci_bus_add_devices
      pci_bus_add_device
        pci_fixup_device(pci_fixup_final)
          pci_fixup_video                    # <-- previous FINAL fixup
        pci_create_sysfs_dev_files
          if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
            sysfs_create_bin_file("rom")     # before 527139d738

Change pci_fixup_video() to be a HEADER fixup so it runs before sysfs
static attributes are initialized.

Rename the Loongson pci_fixup_radeon() to pci_fixup_video() and make its
dmesg logging identical to the others since it is doing the same job.

Link: https://lore.kernel.org/r/YbxqIyrkv3GhZVxx@intel.com
Fixes: 527139d738 ("PCI/sysfs: Convert "rom" to static attribute")
Link: https://lore.kernel.org/r/20220126154001.16895-1-helgaas@kernel.org
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org			# v5.13+
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Krzysztof Wilczyński <kw@linux.com>
2022-01-26 10:41:21 -06:00
David S. Miller
2f65132843 Merge branch 'lan966x-fixes'
Horatiu Vultur says:

====================
net: lan966x: Fixes for sleep in atomic context

This patch series contains 2 fixes for lan966x that is sleeping in atomic
context. The first patch fixes the injection of the frames while the second
one fixes the updating of the MAC table.

v1->v2:
 - correct the fix tag in the second patch, it was using the wrong sha.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-26 15:45:49 +00:00
Horatiu Vultur
77bdaf39f3 net: lan966x: Fix sleep in atomic context when updating MAC table
The function lan966x_mac_wait_for_completion is used to poll the status
of the MAC table using the function readx_poll_timeout. The problem with
this function is that is called also from atomic context. Therefore
update the function to use readx_poll_timeout_atomic.

Fixes: e18aba8941 ("net: lan966x: add mactable support")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-26 15:45:49 +00:00
Horatiu Vultur
b6ab149654 net: lan966x: Fix sleep in atomic context when injecting frames
On lan966x, when injecting a frame it was polling the register
QS_INJ_STATUS to see if it can continue with the injection of the frame.
The problem was that it was using readx_poll_timeout which could sleep
in atomic context.
This patch fixes this issue by using readx_poll_timeout_atomic.

Fixes: d28d6d2e37 ("net: lan966x: add port module support")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-26 15:45:49 +00:00
David S. Miller
8199d0c6ad Merge branch 'dev_addr-const-fixes'
Jakub Kicinski says:

====================
ethernet: fix some esoteric drivers after netdev->dev_addr constification

Looking at recent fixes for drivers which don't get included with
allmodconfig builds I thought it's worth grepping for more instances of:

  dev->dev_addr\[.*\] =

This set contains the fixes.

v2: add last 3 patches which fix drivers for the RiscPC ARM platform.
Thanks to Arnd Bergmann for explaining how to build test that.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-26 15:40:02 +00:00
Jakub Kicinski
8eb86fc2f4 ethernet: seeq/ether3: don't write directly to netdev->dev_addr
netdev->dev_addr is const now.

Compile tested rpc_defconfig w/ GCC 8.5.

Fixes: adeef3e321 ("net: constify netdev->dev_addr")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-26 15:40:01 +00:00
Jakub Kicinski
5518c5246b ethernet: 8390/etherh: don't write directly to netdev->dev_addr
netdev->dev_addr is const now.

Compile tested rpc_defconfig w/ GCC 8.5.

Fixes: adeef3e321 ("net: constify netdev->dev_addr")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-26 15:40:01 +00:00
Jakub Kicinski
98ef22bbae ethernet: i825xx: don't write directly to netdev->dev_addr
netdev->dev_addr is const now.

Compile tested rpc_defconfig w/ GCC 8.5.

Fixes: adeef3e321 ("net: constify netdev->dev_addr")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-26 15:40:01 +00:00
Jakub Kicinski
7f6ec2b2f0 ethernet: broadcom/sb1250-mac: don't write directly to netdev->dev_addr
netdev->dev_addr is const now.

Compile tested bigsur_defconfig and sb1250_swarm_defconfig.

Fixes: adeef3e321 ("net: constify netdev->dev_addr")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-26 15:40:01 +00:00
Jakub Kicinski
14ba66a60f ethernet: tundra: don't write directly to netdev->dev_addr
netdev->dev_addr is const now.

Maintain the questionable offsetting in ndo_set_mac_address.

Compile tested holly_defconfig and mpc7448_hpc2_defconfig.

Fixes: adeef3e321 ("net: constify netdev->dev_addr")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-26 15:40:01 +00:00
Jakub Kicinski
007c95120d ethernet: 3com/typhoon: don't write directly to netdev->dev_addr
This driver casts off the const and writes directly to netdev->dev_addr.
This will result in a MAC address tree corruption and a warning.

Compile tested ppc6xx_defconfig.

Fixes: adeef3e321 ("net: constify netdev->dev_addr")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-26 15:40:01 +00:00
Tong Zhang
7fde14d705 drm/privacy-screen: honor acpi=off in detect_thinkpad_privacy_screen
when acpi=off is provided in bootarg, kernel crash with

[    1.252739] BUG: kernel NULL pointer dereference, address: 0000000000000018
[    1.258308] Call Trace:
[    1.258490]  ? acpi_walk_namespace+0x147/0x147
[    1.258770]  acpi_get_devices+0xe4/0x137
[    1.258921]  ? drm_core_init+0xc0/0xc0 [drm]
[    1.259108]  detect_thinkpad_privacy_screen+0x5e/0xa8 [drm]
[    1.259337]  drm_privacy_screen_lookup_init+0xe/0xe85 [drm]

The reason is that acpi_walk_namespace expects acpi related stuff
initialized but in fact it wouldn't when acpi is set to off. In this case
we should honor acpi=off in detect_thinkpad_privacy_screen().

Signed-off-by: Tong Zhang <ztong0001@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220123091004.763775-1-ztong0001@gmail.com
2022-01-26 15:25:50 +01:00
Namhyung Kim
c5de60cd62 perf/core: Fix cgroup event list management
The active cgroup events are managed in the per-cpu cgrp_cpuctx_list.
This list is only accessed from current cpu and not protected by any
locks.  But from the commit ef54c1a476 ("perf: Rework
perf_event_exit_event()"), it's possible to access (actually modify)
the list from another cpu.

In the perf_remove_from_context(), it can remove an event from the
context without an IPI when the context is not active.  This is not
safe with cgroup events which can have some active events in the
context even if ctx->is_active is 0 at the moment.  The target cpu
might be in the middle of list iteration at the same time.

If the event is enabled when it's about to be closed, it might call
perf_cgroup_event_disable() and list_del() with the cgrp_cpuctx_list
on a different cpu.

This resulted in a crash due to an invalid list pointer access during
the cgroup list traversal on the cpu which the event belongs to.

Let's fallback to IPI to access the cgrp_cpuctx_list from that cpu.
Similarly, perf_install_in_context() should use IPI for the cgroup
events too.

Fixes: ef54c1a476 ("perf: Rework perf_event_exit_event()")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124195808.2252071-1-namhyung@kernel.org
2022-01-26 15:06:06 +01:00
James Clark
961c391217 perf: Always wake the parent event
When using per-process mode and event inheritance is set to true,
forked processes will create a new perf events via inherit_event() ->
perf_event_alloc(). But these events will not have ring buffers
assigned to them. Any call to wakeup will be dropped if it's called on
an event with no ring buffer assigned because that's the object that
holds the wakeup list.

If the child event is disabled due to a call to
perf_aux_output_begin() or perf_aux_output_end(), the wakeup is
dropped leaving userspace hanging forever on the poll.

Normally the event is explicitly re-enabled by userspace after it
wakes up to read the aux data, but in this case it does not get woken
up so the event remains disabled.

This can be reproduced when using Arm SPE and 'stress' which forks once
before running the workload. By looking at the list of aux buffers read,
it's apparent that they stop after the fork:

  perf record -e arm_spe// -vvv -- stress -c 1

With this patch applied they continue to be printed. This behaviour
doesn't happen when using systemwide or per-cpu mode.

Reported-by: Ruben Ayrapetyan <Ruben.Ayrapetyan@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211206113840.130802-2-james.clark@arm.com
2022-01-26 15:06:06 +01:00
Lukas Wunner
2dd8a74fdd serial: core: Initialize rs485 RTS polarity already on probe
RTS polarity of rs485-enabled ports is currently initialized on uart
open via:

tty_port_open()
  tty_port_block_til_ready()
    tty_port_raise_dtr_rts()  # if (C_BAUD(tty))
      uart_dtr_rts()
        uart_port_dtr_rts()

There's at least three problems here:

First, if no baud rate is set, RTS polarity is not initialized.
That's the right thing to do for rs232, but not for rs485, which
requires that RTS is deasserted unconditionally.

Second, if the DeviceTree property "linux,rs485-enabled-at-boot-time" is
present, RTS should be deasserted as early as possible, i.e. on probe.
Otherwise it may remain asserted until first open.

Third, even though RTS is deasserted on open and close, it may
subsequently be asserted by uart_throttle(), uart_unthrottle() or
uart_set_termios() because those functions aren't rs485-aware.
(Only uart_tiocmset() is.)

To address these issues, move RTS initialization from uart_port_dtr_rts()
to uart_configure_port().  Prevent subsequent modification of RTS
polarity by moving the existing rs485 check from uart_tiocmget() to
uart_update_mctrl().

That way, RTS is initialized on probe and then remains unmodified unless
the uart transmits data.  If rs485 is enabled at runtime (instead of at
boot) through a TIOCSRS485 ioctl(), RTS is initialized by the uart
driver's ->rs485_config() callback and then likewise remains unmodified.

The PL011 driver initializes RTS on uart open and prevents subsequent
modification in its ->set_mctrl() callback.  That code is obsoleted by
the present commit, so drop it.

Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Su Bao Cheng <baocheng.su@siemens.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/2d2acaf3a69e89b7bf687c912022b11fd29dfa1e.1642909284.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-26 14:53:12 +01:00
Jochen Mades
62f676ff78 serial: pl011: Fix incorrect rs485 RTS polarity on set_mctrl
Commit 8d47923772 ("serial: amba-pl011: add RS485 support") sought to
keep RTS deasserted on set_mctrl if rs485 is enabled.  However it did so
only if deasserted RTS polarity is high.  Fix it in case it's low.

Fixes: 8d47923772 ("serial: amba-pl011: add RS485 support")
Cc: stable@vger.kernel.org # v5.15+
Cc: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Jochen Mades <jochen@mades.net>
[lukas: copyedit commit message, add stable designation]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/85fa3323ba8c307943969b7343e23f34c3e652ba.1642909284.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-26 14:53:12 +01:00
Valentin Caron
037b91ec77 serial: stm32: fix software flow control transfer
x_char is ignored by stm32_usart_start_tx() when xmit buffer is empty.

Fix start_tx condition to allow x_char to be sent.

Fixes: 48a6092fb4 ("serial: stm32-usart: Add STM32 USART Driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
Link: https://lore.kernel.org/r/20220111164441.6178-3-valentin.caron@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-26 14:52:49 +01:00
Valentin Caron
d3d079bde0 serial: stm32: prevent TDR register overwrite when sending x_char
When sending x_char in stm32_usart_transmit_chars(), driver can overwrite
the value of TDR register by the value of x_char. If this happens, the
previous value that was present in TDR register will not be sent through
uart.

This code checks if the previous value in TDR register is sent before
writing the x_char value into register.

Fixes: 48a6092fb4 ("serial: stm32-usart: Add STM32 USART Driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
Link: https://lore.kernel.org/r/20220111164441.6178-2-valentin.caron@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-26 14:52:44 +01:00
daniel.starke@siemens.com
8838b2af23 tty: n_gsm: fix SW flow control encoding/handling
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.2.7.3 states that DC1 (XON) and DC3 (XOFF)
are the control characters defined in ISO/IEC 646. These shall be quoted if
seen in the data stream to avoid interpretation as flow control characters.

ISO/IEC 646 refers to the set of ISO standards described as the ISO
7-bit coded character set for information interchange. Its final version
is also known as ITU T.50.
See https://www.itu.int/rec/T-REC-T.50-199209-I/en

To abide the standard it is needed to quote DC1 and DC3 correctly if these
are seen as data bytes and not as control characters. The current
implementation already tries to enforce this but fails to catch all
defined cases. 3GPP 27.010 chapter 5.2.7.3 clearly states that the most
significant bit shall be ignored for DC1 and DC3 handling. The current
implementation handles only the case with the most significant bit set 0.
Cases in which DC1 and DC3 have the most significant bit set 1 are left
unhandled.

This patch fixes this by masking the data bytes with ISO_IEC_646_MASK (only
the 7 least significant bits set 1) before comparing them with XON
(a.k.a. DC1) and XOFF (a.k.a. DC3) when testing which byte values need
quotation via byte stuffing.

Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220120101857.2509-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-26 14:51:42 +01:00