IF YOU WOULD LIKE TO GET AN ACCOUNT, please write an
email to Administrator. User accounts are meant only to access repo
and report issues and/or generate pull requests.
This is a purpose-specific Git hosting for
BaseALT
projects. Thank you for your understanding!
Только зарегистрированные пользователи имеют доступ к сервису!
Для получения аккаунта, обратитесь к администратору.
commit 1f7becf1b7e21794fc9d460765fe09679bc9b9e0 upstream.
The injection process of smi has two steps:
Qemu KVM
Step1:
cpu->interrupt_request &= \
~CPU_INTERRUPT_SMI;
kvm_vcpu_ioctl(cpu, KVM_SMI)
call kvm_vcpu_ioctl_smi() and
kvm_make_request(KVM_REQ_SMI, vcpu);
Step2:
kvm_vcpu_ioctl(cpu, KVM_RUN, 0)
call process_smi() if
kvm_check_request(KVM_REQ_SMI, vcpu) is
true, mark vcpu->arch.smi_pending = true;
The vcpu->arch.smi_pending will be set true in step2, unfortunately if
vcpu paused between step1 and step2, the kvm_run->immediate_exit will be
set and vcpu has to exit to Qemu immediately during step2 before mark
vcpu->arch.smi_pending true.
During VM migration, Qemu will get the smi pending status from KVM using
KVM_GET_VCPU_EVENTS ioctl at the downtime, then the smi pending status
will be lost.
Signed-off-by: Jay Zhou <jianjay.zhou@huawei.com>
Signed-off-by: Shengen Zhuang <zhuangshengen@huawei.com>
Message-Id: <20210118084720.1585-1-jianjay.zhou@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 98dd2f108e448988d91e296173e773b06fb978b8 upstream.
The HW_REF_CPU_CYCLES event on the fixed counter 2 is pseudo-encoded as
0x0300 in the intel_perfmon_event_map[]. Correct its usage.
Fixes: 62079d8a4312 ("KVM: PMU: add proper support for fixed counter 2")
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Message-Id: <20201230081916.63417-1-like.xu@linux.intel.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 09e43968db40c33a73e9ddbfd937f46d5c334924 upstream.
The x86-64 psABI [0] specifies special relocation types
(R_X86_64_[REX_]GOTPCRELX) for indirection through the Global Offset
Table, semantically equivalent to R_X86_64_GOTPCREL, which the linker
can take advantage of for optimization (relaxation) at link time. This
is supported by LLD and binutils versions 2.26 onwards.
The compressed kernel is position-independent code, however, when using
LLD or binutils versions before 2.27, it must be linked without the -pie
option. In this case, the linker may optimize certain instructions into
a non-position-independent form, by converting foo@GOTPCREL(%rip) to $foo.
This potential issue has been present with LLD and binutils-2.26 for a
long time, but it has never manifested itself before now:
- LLD and binutils-2.26 only relax
movq foo@GOTPCREL(%rip), %reg
to
leaq foo(%rip), %reg
which is still position-independent, rather than
mov $foo, %reg
which is permitted by the psABI when -pie is not enabled.
- GCC happens to only generate GOTPCREL relocations on mov instructions.
- CLang does generate GOTPCREL relocations on non-mov instructions, but
when building the compressed kernel, it uses its integrated assembler
(due to the redefinition of KBUILD_CFLAGS dropping -no-integrated-as),
which has so far defaulted to not generating the GOTPCRELX
relocations.
Nick Desaulniers reports [1,2]:
"A recent change [3] to a default value of configuration variable
(ENABLE_X86_RELAX_RELOCATIONS OFF -> ON) in LLVM now causes Clang's
integrated assembler to emit R_X86_64_GOTPCRELX/R_X86_64_REX_GOTPCRELX
relocations. LLD will relax instructions with these relocations based
on whether the image is being linked as position independent or not.
When not, then LLD will relax these instructions to use absolute
addressing mode (R_RELAX_GOT_PC_NOPIC). This causes kernels built with
Clang and linked with LLD to fail to boot."
Patch series [4] is a solution to allow the compressed kernel to be
linked with -pie unconditionally, but even if merged is unlikely to be
backported. As a simple solution that can be applied to stable as well,
prevent the assembler from generating the relaxed relocation types using
the -mrelax-relocations=no option. For ease of backporting, do this
unconditionally.
[0] https://gitlab.com/x86-psABIs/x86-64-ABI/-/blob/master/x86-64-ABI/linker-optimization.tex#L65
[1] https://lore.kernel.org/lkml/20200807194100.3570838-1-ndesaulniers@google.com/
[2] https://github.com/ClangBuiltLinux/linux/issues/1121
[3] https://reviews.llvm.org/rGc41a18cf61790fc898dcda1055c3efbf442c14c0
[4] https://lore.kernel.org/lkml/20200731202738.2577854-1-nivedita@alum.mit.edu/
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200812004308.1448603-1-nivedita@alum.mit.edu
[nc: Backport to 4.9]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cb7f4a8b1fb426a175d1708f05581939c61329d4 upstream.
In mtrr_type_lookup(), if the input memory address region is not in the
MTRR, over 4GB, and not over the top of memory, a write-back attribute
is returned. These condition checks are for ensuring the input memory
address region is actually mapped to the physical memory.
However, if the end address is just aligned with the top of memory,
the condition check treats the address is over the top of memory, and
write-back attribute is not returned.
And this hits in a real use case with NVDIMM: the nd_pmem module tries
to map NVDIMMs as cacheable memories when NVDIMMs are connected. If a
NVDIMM is the last of the DIMMs, the performance of this NVDIMM becomes
very low since it is aligned with the top of memory and its memory type
is uncached-minus.
Move the input end address change to inclusive up into
mtrr_type_lookup(), before checking for the top of memory in either
mtrr_type_lookup_{variable,fixed}() helpers.
[ bp: Massage commit message. ]
Fixes: 0cc705f56e40 ("x86/mm/mtrr: Clean up mtrr_type_lookup()")
Signed-off-by: Ying-Tsun Huang <ying-tsun.huang@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201215070721.4349-1-ying-tsun.huang@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d1c5246e08eb64991001d97a3bd119c93edbc79a upstream.
Commit
28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
introduced a new location where a pmd was released, but neglected to
run the pmd page destructor. In fact, this happened previously for a
different pmd release path and was fixed by commit:
c283610e44ec ("x86, mm: do not leak page->ptl for pmd page tables").
This issue was hidden until recently because the failure mode is silent,
but commit:
b2b29d6d0119 ("mm: account PMD tables like PTE tables")
turns the failure mode into this signature:
BUG: Bad page state in process lt-pmem-ns pfn:15943d
page:000000007262ed7b refcount:0 mapcount:-1024 mapping:0000000000000000 index:0x0 pfn:0x15943d
flags: 0xaffff800000000()
raw: 00affff800000000 dead000000000100 0000000000000000 0000000000000000
raw: 0000000000000000 ffff913a029bcc08 00000000fffffbff 0000000000000000
page dumped because: nonzero mapcount
[..]
dump_stack+0x8b/0xb0
bad_page.cold+0x63/0x94
free_pcp_prepare+0x224/0x270
free_unref_page+0x18/0xd0
pud_free_pmd_page+0x146/0x160
ioremap_pud_range+0xe3/0x350
ioremap_page_range+0x108/0x160
__ioremap_caller.constprop.0+0x174/0x2b0
? memremap+0x7a/0x110
memremap+0x7a/0x110
devm_memremap+0x53/0xa0
pmem_attach_disk+0x4ed/0x530 [nd_pmem]
? __devm_release_region+0x52/0x80
nvdimm_bus_probe+0x85/0x210 [libnvdimm]
Given this is a repeat occurrence it seemed prudent to look for other
places where this destructor might be missing and whether a better
helper is needed. try_to_free_pmd_page() looks like a candidate, but
testing with setting up and tearing down pmd mappings via the dax unit
tests is thus far not triggering the failure.
As for a better helper pmd_free() is close, but it is a messy fit
due to requiring an @mm arg. Also, ___pmd_free_tlb() wants to call
paravirt_tlb_remove_table() instead of free_page(), so open-coded
pgtable_pmd_page_dtor() seems the best way forward for now.
Debugged together with Matthew Wilcox <willy@infradead.org>.
Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/160697689204.605323.17629854984697045602.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a368d7fd2a3c6babb852fe974018dd97916bcd3b upstream.
Omitting suffixes from instructions in AT&T mode is bad practice when
operand size cannot be determined by the assembler from register
operands, and is likely going to be warned about by upstream gas in the
future (mine does already). Add the single missing suffix here.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/5A93F96902000078001ABAC8@prv-mh.provo.novell.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 78ff2733ff352175eb7f4418a34654346e1b6cd2 ]
Fix to restore BTF if single-stepping causes a page fault and
it is cancelled.
Usually the BTF flag was restored when the single stepping is done
(in resume_execution()). However, if a page fault happens on the
single stepping instruction, the fault handler is invoked and
the single stepping is cancelled. Thus, the BTF flag is not
restored.
Fixes: 1ecc798c6764 ("x86: debugctlmsr kprobes")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/160389546985.106936.12727996109376240993.stgit@devnote2
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4e9a5ae8df5b3365183150f6df49e49dece80d8c upstream
Since insn.prefixes.nbytes can be bigger than the size of
insn.prefixes.bytes[] when a prefix is repeated, the proper check must
be
insn.prefixes.bytes[i] != 0 and i < 4
instead of using insn.prefixes.nbytes.
Introduce a for_each_insn_prefix() macro for this purpose. Debugged by
Kees Cook <keescook@chromium.org>.
[ bp: Massage commit message, sync with the respective header in tools/
and drop "we". ]
Fixes: 2b1444983508 ("uprobes, mm, x86: Add the ability to install and remove uprobes breakpoints")
Reported-by: syzbot+9b64b619f10f19d19a7c@syzkaller.appspotmail.com
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/160697103739.3146288.7437620795200799020.stgit@devnote2
[sudip: adjust context, use old insn.h]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 33fc379df76b4991e5ae312f07bcd6820811971e upstream.
When spectre_v2_user={seccomp,prctl},ibpb is specified on the command
line, IBPB is force-enabled and STIPB is conditionally-enabled (or not
available).
However, since
21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.")
the spectre_v2_user_ibpb variable is set to SPECTRE_V2_USER_{PRCTL,SECCOMP}
instead of SPECTRE_V2_USER_STRICT, which is the actual behaviour.
Because the issuing of IBPB relies on the switch_mm_*_ibpb static
branches, the mitigations behave as expected.
Since
1978b3a53a74 ("x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP")
this discrepency caused the misreporting of IB speculation via prctl().
On CPUs with STIBP always-on and spectre_v2_user=seccomp,ibpb,
prctl(PR_GET_SPECULATION_CTRL) would return PR_SPEC_PRCTL |
PR_SPEC_ENABLE instead of PR_SPEC_DISABLE since both IBPB and STIPB are
always on. It also allowed prctl(PR_SET_SPECULATION_CTRL) to set the IB
speculation mode, even though the flag is ignored.
Similarly, for CPUs without SMT, prctl(PR_GET_SPECULATION_CTRL) should
also return PR_SPEC_DISABLE since IBPB is always on and STIBP is not
available.
[ bp: Massage commit message. ]
Fixes: 21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.")
Fixes: 1978b3a53a74 ("x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP")
Signed-off-by: Anand K Mistry <amistry@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201110123349.1.Id0cbf996d2151f4c143c90f9028651a5b49a5908@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ebd19fc372e3e78bf165f230e7c084e304441c08 ]
This change switches rapl to use PMU_FORMAT_ATTR, and fixes two other
macros to use device_attribute instead of kobj_attribute to avoid
callback type mismatches that trip indirect call checking with Clang's
Control-Flow Integrity (CFI).
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20201113183126.1239404-1-samitolvanen@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 65cae18882f943215d0505ddc7e70495877308e6 ]
When booting a hyperthreaded system with the kernel parameter
'mitigations=auto,nosmt', the following warning occurs:
WARNING: CPU: 0 PID: 1 at drivers/xen/events/events_base.c:1112 unbind_from_irqhandler+0x4e/0x60
...
Hardware name: Xen HVM domU, BIOS 4.2.amazon 08/24/2006
...
Call Trace:
xen_uninit_lock_cpu+0x28/0x62
xen_hvm_cpu_die+0x21/0x30
takedown_cpu+0x9c/0xe0
? trace_suspend_resume+0x60/0x60
cpuhp_invoke_callback+0x9a/0x530
_cpu_up+0x11a/0x130
cpu_up+0x7e/0xc0
bringup_nonboot_cpus+0x48/0x50
smp_init+0x26/0x79
kernel_init_freeable+0xea/0x229
? rest_init+0xaa/0xaa
kernel_init+0xa/0x106
ret_from_fork+0x35/0x40
The secondary CPUs are not activated with the nosmt mitigations and only
the primary thread on each CPU core is used. In this situation,
xen_hvm_smp_prepare_cpus(), and more importantly xen_init_lock_cpu(), is
not called, so the lock_kicker_irq is not initialized for the secondary
CPUs. Let's fix this by exiting early in xen_uninit_lock_cpu() if the
irq is not set to avoid the warning from above for each secondary CPU.
Signed-off-by: Brian Masney <bmasney@redhat.com>
Link: https://lore.kernel.org/r/20201107011119.631442-1-bmasney@redhat.com
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1a371e67dc77125736cc56d3a0893f06b75855b6 upstream.
Currently, scan_microcode() leverages microcode_matches() to check
if the microcode matches the CPU by comparing the family and model.
However, the processor stepping and flags of the microcode signature
should also be considered when saving a microcode patch for early
update.
Use find_matching_signature() in scan_microcode() and get rid of the
now-unused microcode_matches() which is a good cleanup in itself.
Complete the verification of the patch being saved for early loading in
save_microcode_patch() directly. This needs to be done there too because
save_mc_for_early() will call save_microcode_patch() too.
The second reason why this needs to be done is because the loader still
tries to support, at least hypothetically, mixed-steppings systems and
thus adds all patches to the cache that belong to the same CPU model
albeit with different steppings.
For example:
microcode: CPU: sig=0x906ec, pf=0x2, rev=0xd6
microcode: mc_saved[0]: sig=0x906e9, pf=0x2a, rev=0xd6, total size=0x19400, date = 2020-04-23
microcode: mc_saved[1]: sig=0x906ea, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27
microcode: mc_saved[2]: sig=0x906eb, pf=0x2, rev=0xd6, total size=0x19400, date = 2020-04-23
microcode: mc_saved[3]: sig=0x906ec, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27
microcode: mc_saved[4]: sig=0x906ed, pf=0x22, rev=0xd6, total size=0x19400, date = 2020-04-23
The patch which is being saved for early loading, however, can only be
the one which fits the CPU this runs on so do the signature verification
before saving.
[ bp: Do signature verification in save_microcode_patch()
and rewrite commit message. ]
Fixes: ec400ddeff20 ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208535
Link: https://lkml.kernel.org/r/20201113015923.13960-1-yu.c.chen@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9511bce9fe8e5e6c0f923c09243a713eba560141 upstream
As Miklos reported and suggested:
"This pattern repeats two times in trace_uprobe.c and in
kernel/events/core.c as well:
ret = kern_path(filename, LOOKUP_FOLLOW, &path);
if (ret)
goto fail_address_parse;
inode = igrab(d_inode(path.dentry));
path_put(&path);
And it's wrong. You can only hold a reference to the inode if you
have an active ref to the superblock as well (which is normally
through path.mnt) or holding s_umount.
This way unmounting the containing filesystem while the tracepoint is
active will give you the "VFS: Busy inodes after unmount..." message
and a crash when the inode is finally put.
Solution: store path instead of inode."
This patch fixes the issue in kernel/event/core.c.
Reviewed-and-tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reported-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <kernel-team@fb.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 375637bc5249 ("perf/core: Introduce address range filtering")
Link: http://lkml.kernel.org/r/20180418062907.3210386-2-songliubraving@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[sudip: Backported to 4.9: use file_inode()]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1978b3a53a74e3230cd46932b149c6e62e832e9a upstream.
On AMD CPUs which have the feature X86_FEATURE_AMD_STIBP_ALWAYS_ON,
STIBP is set to on and
spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED
At the same time, IBPB can be set to conditional.
However, this leads to the case where it's impossible to turn on IBPB
for a process because in the PR_SPEC_DISABLE case in ib_prctl_set() the
spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED
condition leads to a return before the task flag is set. Similarly,
ib_prctl_get() will return PR_SPEC_DISABLE even though IBPB is set to
conditional.
More generally, the following cases are possible:
1. STIBP = conditional && IBPB = on for spectre_v2_user=seccomp,ibpb
2. STIBP = on && IBPB = conditional for AMD CPUs with
X86_FEATURE_AMD_STIBP_ALWAYS_ON
The first case functions correctly today, but only because
spectre_v2_user_ibpb isn't updated to reflect the IBPB mode.
At a high level, this change does one thing. If either STIBP or IBPB
is set to conditional, allow the prctl to change the task flag.
Also, reflect that capability when querying the state. This isn't
perfect since it doesn't take into account if only STIBP or IBPB is
unconditionally on. But it allows the conditional feature to work as
expected, without affecting the unconditional one.
[ bp: Massage commit message and comment; space out statements for
better readability. ]
Fixes: 21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.")
Signed-off-by: Anand K Mistry <amistry@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20201105163246.v2.1.Ifd7243cd3e2c2206a893ad0a5b9a4f19549e22c6@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit afc18069a2cb7ead5f86623a5f3d4ad6e21f940d ]
kexec_file_load() currently reuses the old boot_params.screen_info,
but if drivers have change the hardware state, boot_param.screen_info
could contain invalid info.
For example, the video type might be no longer VGA, or the frame buffer
address might be changed. If the kexec kernel keeps using the old screen_info,
kexec'ed kernel may attempt to write to an invalid framebuffer
memory region.
There are two screen_info instances globally available, boot_params.screen_info
and screen_info. Later one is a copy, and is updated by drivers.
So let kexec_file_load use the updated copy.
[ mingo: Tidied up the changelog. ]
Signed-off-by: Kairui Song <kasong@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20201014092429.1415040-2-kasong@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 36e1be8ada994d509538b3b1d0af8b63c351e729 upstream.
Neither IbsBrTarget nor OPDATA4 are populated in IBS Fetch mode.
Don't accumulate them into raw sample user data in that case.
Also, in Fetch mode, add saving the IBS Fetch Control Extended MSR.
Technically, there is an ABI change here with respect to the IBS raw
sample data format, but I don't see any perf driver version information
being included in perf.data file headers, but, existing users can detect
whether the size of the sample record has reduced by 8 bytes to
determine whether the IBS driver has this fix.
Fixes: 904cb3677f3a ("perf/x86/amd/ibs: Update IBS MSRs and feature definitions")
Reported-by: Stephane Eranian <stephane.eranian@google.com>
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200908214740.18097-6-kim.phillips@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 680d69635005ba0e58fe3f4c52fc162b8fc743b0 upstream.
get_ibs_op_count() adds hardware's current count (IbsOpCurCnt) bits
to its count regardless of hardware's valid status.
According to the PPR for AMD Family 17h Model 31h B0 55803 Rev 0.54,
if the counter rolls over, valid status is set, and the lower 7 bits
of IbsOpCurCnt are randomized by hardware.
Don't include those bits in the driver's event count.
Fixes: 8b1e13638d46 ("perf/x86-ibs: Fix usage of IBS op current count")
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 221bfce5ebbdf72ff08b3bf2510ae81058ee568b upstream.
Stephane Eranian found a bug in that IBS' current Fetch counter was not
being reset when the driver would write the new value to clear it along
with the enable bit set, and found that adding an MSR write that would
first disable IBS Fetch would make IBS Fetch reset its current count.
Indeed, the PPR for AMD Family 17h Model 31h B0 55803 Rev 0.54 - Sep 12,
2019 states "The periodic fetch counter is set to IbsFetchCnt [...] when
IbsFetchEn is changed from 0 to 1."
Explicitly set IbsFetchEn to 0 and then to 1 when re-enabling IBS Fetch,
so the driver properly resets the internal counter to 0 and IBS
Fetch starts counting again.
A family 15h machine tested does not have this problem, and the extra
wrmsr is also not needed on Family 19h, so only do the extra wrmsr on
families 16h through 18h.
Reported-by: Stephane Eranian <stephane.eranian@google.com>
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
[peterz: optimized]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a9e2e0ae686094571378c72d8146b5a1a92d0652 ]
Per Intel's SDM, RDPID takes a #UD if it is unsupported, which is more or
less what KVM is emulating when MSR_TSC_AUX is not available. In fact,
there are no scenarios in which RDPID is supposed to #GP.
Fixes: fb6d4d340e ("KVM: x86: emulate RDPID")
Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
Message-Id: <1598581422-76264-1-git-send-email-robert.hu@linux.intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e89505698c9f70125651060547da4ff5046124fc upstream.
Call kvm_mmu_commit_zap_page() after exiting the "prepare zap" loop in
kvm_recover_nx_lpages() to finish zapping pages in the unlikely event
that the loop exited due to lpage_disallowed_mmu_pages being empty.
Because the recovery thread drops mmu_lock() when rescheduling, it's
possible that lpage_disallowed_mmu_pages could be emptied by a different
thread without to_zap reaching zero despite to_zap being derived from
the number of disallowed lpages.
Fixes: 1aa9b9572b105 ("kvm: x86: mmu: Recovery of shattered NX large pages")
Cc: Junaid Shahid <junaids@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200923183735.584-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a7ef9ba986b5fae9d80f8a7b31db0423687efe4e ]
Prevent the compiler from uninlining and creating traceable/probable
functions as this is invoked _after_ context tracking switched to
CONTEXT_USER and rcu idle.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200505134340.902709267@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7289fdb5dcdbc5155b5531529c44105868a762f2 ]
Fixes a NULL pointer dereference, caused by the PIT firing an interrupt
before the interrupt table has been initialized.
SET_PIT2 can race with the creation of the IRQchip. In particular,
if SET_PIT2 is called with a low PIT timer period (after the creation of
the IOAPIC, but before the instantiation of the irq routes), the PIT can
fire an interrupt at an uninitialized table.
Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Jon Cargille <jcargill@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20200416191152.259434-1-jcargill@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 16171bffc829272d5e6014bad48f680cb50943d9 ]
Alex Shi reported the pkey macros above arch_set_user_pkey_access()
to be unused. They are unused, and even refer to a nonexistent
CONFIG option.
But, they might have served a good use, which was to ensure that
the code does not try to set values that would not fit in the
PKRU register. As it stands, a too-large 'pkey' value would
be likely to silently overflow the u32 new_pkru_bits.
Add a check to look for overflows. Also add a comment to remind
any future developer to closely examine the types used to store
pkey values if arch_max_pkey() ever changes.
This boots and passes the x86 pkey selftests.
Reported-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200122165346.AD4DA150@viggo.jf.intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 147f1a1fe5d7e6b01b8df4d0cbd6f9eaf6b6c73b ]
The "u" field in the event has three states, -1/0/1. Using u8 however means that
comparison with -1 will always fail, so change to signed char.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 72a9c673636b779e370983fea08e40f97039b981 upstream.
A spanking new machine I just got has all but one USB ports wired as 3.0.
Booting defconfig resulted in no keyboard or mouse, which was pretty
uncool. Let's enable that -- USB3 is ubiquitous rather than an oddity.
As 'y' not 'm' -- recovering from initrd problems needs a keyboard.
Also add it to the 32-bit defconfig.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-usb@vger.kernel.org
Link: http://lkml.kernel.org/r/20181009062803.4332-1-kilobyte@angband.pl
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 99b82a1437cb31340dbb2c437a2923b9814a7b15 upstream.
According to SDM 27.2.4, Event delivery causes an APIC-access VM exit.
Don't report internal error and freeze guest when event delivery causes
an APIC-access exit, it is handleable and the event will be re-injected
during the next vmentry.
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1597827327-25055-2-git-send-email-wanpengli@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 973c096f6a85e5b5f2a295126ba6928d9a6afd45 upstream.
Yunhai Zhang recently fixed a VGA software scrollback bug in commit
ebfdfeeae8c0 ("vgacon: Fix for missing check in scrollback handling"),
but that then made people look more closely at some of this code, and
there were more problems on the vgacon side, but also the fbcon software
scrollback.
We don't really have anybody who maintains this code - probably because
nobody actually _uses_ it any more. Sure, people still use both VGA and
the framebuffer consoles, but they are no longer the main user
interfaces to the kernel, and haven't been for decades, so these kinds
of extra features end up bitrotting and not really being used.
So rather than try to maintain a likely unused set of code, I'll just
aggressively remove it, and see if anybody even notices. Maybe there
are people who haven't jumped on the whole GUI badnwagon yet, and think
it's just a fad. And maybe those people use the scrollback code.
If that turns out to be the case, we can resurrect this again, once
we've found the sucker^Wmaintainer for it who actually uses it.
Reported-by: NopNop Nop <nopitydays@gmail.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Cc: 张云海 <zhangyunhai@nsfocus.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 22636f8c9511245cb3c8412039f1dd95afb3aa59 upstream.
Omitting suffixes from instructions in AT&T mode is bad practice when
operand size cannot be determined by the assembler from register
operands, and is likely going to be warned about by upstream gas in the
future (mine does already). Add the missing suffixes here. Note that for
64-bit this means some operations change from being 32-bit to 64-bit.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/5A93F98702000078001ABACC@prv-mh.provo.novell.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3c52b5c64326d9dcfee4e10611c53ec1b1b20675 upstream.
There is no need for \n\t in front of CC_SET(), as the macro already includes these two.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170906151808.5634-1-ubizjak@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bdd65589593edd79b6a12ce86b3b7a7c6dae5208 upstream.
0day reported a possible circular locking dependency:
Chain exists of:
&irq_desc_lock_class --> console_owner --> &port_lock_key
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&port_lock_key);
lock(console_owner);
lock(&port_lock_key);
lock(&irq_desc_lock_class);
The reason for this is a printk() in the i8259 interrupt chip driver
which is invoked with the irq descriptor lock held, which reverses the
lock operations vs. printk() from arbitrary contexts.
Switch the printk() to printk_deferred() to avoid that.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87365abt2v.fsf@nanos.tec.linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d2286ba7d574ba3103a421a2f9ec17cb5b0d87a1 upstream.
Prevent setting the tscdeadline timer if the lapic is hw disabled.
Fixes: bce87cce88 (KVM: x86: consolidate different ways to test for in-kernel LAPIC)
Cc: <stable@vger.kernel.org>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1596165141-28874-1-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit de2b41be8fcccb2f5b6c480d35df590476344201 ]
On x86-32 the idt_table with 256 entries needs only 2048 bytes. It is
page-aligned, but the end of the .bss..page_aligned section is not
guaranteed to be page-aligned.
As a result, objects from other .bss sections may end up on the same 4k
page as the idt_table, and will accidentially get mapped read-only during
boot, causing unexpected page-faults when the kernel writes to them.
This could be worked around by making the objects in the page aligned
sections page sized, but that's wrong.
Explicit sections which store only page aligned objects have an implicit
guarantee that the object is alone in the page in which it is placed. That
works for all objects except the last one. That's inconsistent.
Enforcing page sized objects for these sections would wreckage memory
sanitizers, because the object becomes artificially larger than it should
be and out of bound access becomes legit.
Align the end of the .bss..page_aligned and .data..page_aligned section on
page-size so all objects places in these sections are guaranteed to have
their own page.
[ tglx: Amended changelog ]
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200721093448.10417-1-joro@8bytes.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6a03469a1edc94da52b65478f1e00837add869a3 ]
With CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y, we compile the kernel with
-fdata-sections, which also splits the .bss section.
The new section, with a new .bss.* name, which pattern gets missed by the
main x86 linker script which only expects the '.bss' name. This results
in the discarding of the second part and a too small, truncated .bss
section and an unhappy, non-working kernel.
Use the common BSS_MAIN macro in the linker script to properly capture
and merge all the generated BSS sections.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20190415164956.124067-1-samitolvanen@google.com
[ Extended the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 81e96851ea32deb2c921c870eecabf335f598aeb ]
The clang integrated assembler requires the 'cmp' instruction to
have a length prefix here:
arch/x86/math-emu/wm_sqrt.S:212:2: error: ambiguous instructions require an explicit suffix (could be 'cmpb', 'cmpw', or 'cmpl')
cmp $0xffffffff,-24(%ebp)
^
Make this a 32-bit comparison, which it was clearly meant to be.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lkml.kernel.org/r/20200527135352.1198078-1-arnd@arndb.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5ecad245de2ae23dc4e2dbece92f8ccfbaed2fa7 upstream.
Bit 8 would be the "global" bit, which does not quite make sense for non-leaf
page table entries. Intel ignores it; AMD ignores it in PDEs and PDPEs, but
reserves it in PML4Es.
Probably, earlier versions of the AMD manual documented it as reserved in PDPEs
as well, and that behavior made it into KVM as well as kvm-unit-tests; fix it.
Cc: stable@vger.kernel.org
Reported-by: Nadav Amit <namit@vmware.com>
Fixes: a0c0feb57992 ("KVM: x86: reserve bit 8 of non-leaf PDPEs and PML4Es in 64-bit mode on AMD", 2014-09-03)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bf10bd0be53282183f374af23577b18b5fbf7801 upstream.
Only MSR address range 0x800 through 0x8ff is architecturally reserved
and dedicated for accessing APIC registers in x2APIC mode.
Fixes: 0105d1a52640 ("KVM: x2apic interface to lapic")
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-Id: <20200616073307.16440-1-xiaoyao.li@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9b38cc704e844e41d9cf74e647bff1d249512cb3 ]
Ziqian reported lockup when adding retprobe on _raw_spin_lock_irqsave.
My test was also able to trigger lockdep output:
============================================
WARNING: possible recursive locking detected
5.6.0-rc6+ #6 Not tainted
--------------------------------------------
sched-messaging/2767 is trying to acquire lock:
ffffffff9a492798 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_hash_lock+0x52/0xa0
but task is already holding lock:
ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(kretprobe_table_locks[i].lock));
lock(&(kretprobe_table_locks[i].lock));
*** DEADLOCK ***
May be due to missing lock nesting notation
1 lock held by sched-messaging/2767:
#0: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50
stack backtrace:
CPU: 3 PID: 2767 Comm: sched-messaging Not tainted 5.6.0-rc6+ #6
Call Trace:
dump_stack+0x96/0xe0
__lock_acquire.cold.57+0x173/0x2b7
? native_queued_spin_lock_slowpath+0x42b/0x9e0
? lockdep_hardirqs_on+0x590/0x590
? __lock_acquire+0xf63/0x4030
lock_acquire+0x15a/0x3d0
? kretprobe_hash_lock+0x52/0xa0
_raw_spin_lock_irqsave+0x36/0x70
? kretprobe_hash_lock+0x52/0xa0
kretprobe_hash_lock+0x52/0xa0
trampoline_handler+0xf8/0x940
? kprobe_fault_handler+0x380/0x380
? find_held_lock+0x3a/0x1c0
kretprobe_trampoline+0x25/0x50
? lock_acquired+0x392/0xbc0
? _raw_spin_lock_irqsave+0x50/0x70
? __get_valid_kprobe+0x1f0/0x1f0
? _raw_spin_unlock_irqrestore+0x3b/0x40
? finish_task_switch+0x4b9/0x6d0
? __switch_to_asm+0x34/0x70
? __switch_to_asm+0x40/0x70
The code within the kretprobe handler checks for probe reentrancy,
so we won't trigger any _raw_spin_lock_irqsave probe in there.
The problem is in outside kprobe_flush_task, where we call:
kprobe_flush_task
kretprobe_table_lock
raw_spin_lock_irqsave
_raw_spin_lock_irqsave
where _raw_spin_lock_irqsave triggers the kretprobe and installs
kretprobe_trampoline handler on _raw_spin_lock_irqsave return.
The kretprobe_trampoline handler is then executed with already
locked kretprobe_table_locks, and first thing it does is to
lock kretprobe_table_locks ;-) the whole lockup path like:
kprobe_flush_task
kretprobe_table_lock
raw_spin_lock_irqsave
_raw_spin_lock_irqsave ---> probe triggered, kretprobe_trampoline installed
---> kretprobe_table_locks locked
kretprobe_trampoline
trampoline_handler
kretprobe_hash_lock(current, &head, &flags); <--- deadlock
Adding kprobe_busy_begin/end helpers that mark code with fake
probe installed to prevent triggering of another kprobe within
this code.
Using these helpers in kprobe_flush_task, so the probe recursion
protection check is hit and the probe is never set to prevent
above lockup.
Link: http://lkml.kernel.org/r/158927059835.27680.7011202830041561604.stgit@devnote2
Fixes: ef53d9c5e4da ("kprobes: improve kretprobe scalability with hashed locking")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Reported-by: "Ziqian SUN (Zamir)" <zsun@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b191fa96ea6dc00d331dcc28c1f7db5e075693a0 ]
Avoid kretprobe recursion loop bg by setting a dummy
kprobes to current_kprobe per-CPU variable.
This bug has been introduced with the asm-coded trampoline
code, since previously it used another kprobe for hooking
the function return placeholder (which only has a nop) and
trampoline handler was called from that kprobe.
This revives the old lost kprobe again.
With this fix, we don't see deadlock anymore.
And you can see that all inner-called kretprobe are skipped.
event_1 235 0
event_2 19375 19612
The 1st column is recorded count and the 2nd is missed count.
Above shows (event_1 rec) + (event_2 rec) ~= (event_2 missed)
(some difference are here because the counter is racy)
Reported-by: Andrea Righi <righi.andrea@gmail.com>
Tested-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: c9becf58d935 ("[PATCH] kretprobe: kretprobe-booster")
Link: http://lkml.kernel.org/r/155094064889.6137.972160690963039.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit bc310baf2ba381c648983c7f4748327f17324562 upstream.
The final build stage of the x86 kernel captures some symbol
addresses from the decompressor binary and copies them into zoffset.h.
It uses sed with a regular expression that matches the address, symbol
type and symbol name, and mangles the captured addresses and the names
of symbols of interest into #define directives that are added to
zoffset.h
The symbol type is indicated by a single letter, which we match
strictly: only letters in the set 'ABCDGRSTVW' are matched, even
though the actual symbol type is relevant and therefore ignored.
Commit bc7c9d620 ("efi/libstub/x86: Force 'hidden' visibility for
extern declarations") made a change to the way external symbol
references are classified, resulting in 'startup_32' now being
emitted as a hidden symbol. This prevents the use of GOT entries to
refer to this symbol via its absolute address, which recent toolchains
(including Clang based ones) already avoid by default, making this
change a no-op in the majority of cases.
However, as it turns out, the LLVM linker classifies such hidden
symbols as symbols with static linkage in fully linked ELF binaries,
causing tools such as NM to output a lowercase 't' rather than an upper
case 'T' for the type of such symbols. Since our sed expression only
matches upper case letters for the symbol type, the line describing
startup_32 is disregarded, resulting in a build error like the following
arch/x86/boot/header.S:568:18: error: symbol 'ZO_startup_32' can not be
undefined in a subtraction expression
init_size: .long (0x00000000008fd000 - ZO_startup_32 +
(((0x0000000001f6361c + ((0x0000000001f6361c >> 8) + 65536)
- 0x00000000008c32e5) + 4095) & ~4095)) # kernel initialization size
Given that we are only interested in the value of the symbol, let's match
any character in the set 'a-zA-Z' instead.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5214028dd89e49ba27007c3ee475279e584261f0 ]
For the 32-bit kernel, as described in
6d92bc9d483a ("x86/build: Build compressed x86 kernels as PIE"),
pre-2.26 binutils generates R_386_32 relocations in PIE mode. Since the
startup code does not perform relocation, any reloc entry with R_386_32
will remain as 0 in the executing code.
Commit
974f221c84b0 ("x86/boot: Move compressed kernel to the end of the
decompression buffer")
added a new symbol _end but did not mark it hidden, which doesn't give
the correct offset on older linkers. This causes the compressed kernel
to be copied beyond the end of the decompression buffer, rather than
flush against it. This region of memory may be reserved or already
allocated for other purposes by the bootloader.
Mark _end as hidden to fix. This changes the relocation from R_386_32 to
R_386_RELATIVE even on the pre-2.26 binutils.
For 64-bit, this is not strictly necessary, as the 64-bit kernel is only
built as PIE if the linker supports -z noreloc-overflow, which implies
binutils-2.27+, but for consistency, mark _end as hidden here too.
The below illustrates the before/after impact of the patch using
binutils-2.25 and gcc-4.6.4 (locally compiled from source) and QEMU.
Disassembly before patch:
48: 8b 86 60 02 00 00 mov 0x260(%esi),%eax
4e: 2d 00 00 00 00 sub $0x0,%eax
4f: R_386_32 _end
Disassembly after patch:
48: 8b 86 60 02 00 00 mov 0x260(%esi),%eax
4e: 2d 00 f0 76 00 sub $0x76f000,%eax
4f: R_386_RELATIVE *ABS*
Dump from extract_kernel before patch:
early console in extract_kernel
input_data: 0x0207c098 <--- this is at output + init_size
input_len: 0x0074fef1
output: 0x01000000
output_len: 0x00fa63d0
kernel_total_size: 0x0107c000
needed_size: 0x0107c000
Dump from extract_kernel after patch:
early console in extract_kernel
input_data: 0x0190d098 <--- this is at output + init_size - _end
input_len: 0x0074fef1
output: 0x01000000
output_len: 0x00fa63d0
kernel_total_size: 0x0107c000
needed_size: 0x0107c000
Fixes: 974f221c84b0 ("x86/boot: Move compressed kernel to the end of the decompression buffer")
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200207214926.3564079-1-nivedita@alum.mit.edu
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 2ebac8bb3c2d35f5135466490fc8eeaf3f3e2d37 upstream.
Consult only the basic exit reason, i.e. bits 15:0 of vmcs.EXIT_REASON,
when determining whether a nested VM-Exit should be reflected into L1 or
handled by KVM in L0.
For better or worse, the switch statement in nested_vmx_exit_reflected()
currently defaults to "true", i.e. reflects any nested VM-Exit without
dedicated logic. Because the case statements only contain the basic
exit reason, any VM-Exit with modifier bits set will be reflected to L1,
even if KVM intended to handle it in L0.
Practically speaking, this only affects EXIT_REASON_MCE_DURING_VMENTRY,
i.e. a #MC that occurs on nested VM-Enter would be incorrectly routed to
L1, as "failed VM-Entry" is the only modifier that KVM can currently
encounter. The SMM modifiers will never be generated as KVM doesn't
support/employ a SMI Transfer Monitor. Ditto for "exit from enclave",
as KVM doesn't yet support virtualizing SGX, i.e. it's impossible to
enter an enclave in a KVM guest (L1 or L2).
Fixes: 644d711aa0e1 ("KVM: nVMX: Deciding if L0 or L1 should handle an L2 exit")
Cc: Jim Mattson <jmattson@google.com>
Cc: Xiaoyao Li <xiaoyao.li@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200227174430.26371-1-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6c0238c4a62b3a0b1201aeb7e33a4636d552a436 upstream.
Restoring the ASID from the hsave area on VMEXIT is wrong, because its
value depends on the handling of TLB flushes. Just skipping the field in
copy_vmcb_control_area will do.
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4d8df8cbb9156b0a0ab3f802b80cb5db57acc0bf ]
Currently, it is possible to enable indirect branch speculation even after
it was force-disabled using the PR_SPEC_FORCE_DISABLE option. Moreover, the
PR_GET_SPECULATION_CTRL command gives afterwards an incorrect result
(force-disabled when it is in fact enabled). This also is inconsistent
vs. STIBP and the documention which cleary states that
PR_SPEC_FORCE_DISABLE cannot be undone.
Fix this by actually enforcing force-disabled indirect branch
speculation. PR_SPEC_ENABLE called after PR_SPEC_FORCE_DISABLE now fails
with -EPERM as described in the documentation.
Fixes: 9137bb27e60e ("x86/speculation: Add prctl() control for indirect branch speculation")
Signed-off-by: Anthony Steinhauser <asteinhauser@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 21998a351512eba4ed5969006f0c55882d995ada ]
When STIBP is unavailable or enhanced IBRS is available, Linux
force-disables the IBPB mitigation of Spectre-BTB even when simultaneous
multithreading is disabled. While attempts to enable IBPB using
prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, ...) fail with
EPERM, the seccomp syscall (or its prctl(PR_SET_SECCOMP, ...) equivalent)
which are used e.g. by Chromium or OpenSSH succeed with no errors but the
application remains silently vulnerable to cross-process Spectre v2 attacks
(classical BTB poisoning). At the same time the SYSFS reporting
(/sys/devices/system/cpu/vulnerabilities/spectre_v2) displays that IBPB is
conditionally enabled when in fact it is unconditionally disabled.
STIBP is useful only when SMT is enabled. When SMT is disabled and STIBP is
unavailable, it makes no sense to force-disable also IBPB, because IBPB
protects against cross-process Spectre-BTB attacks regardless of the SMT
state. At the same time since missing STIBP was only observed on AMD CPUs,
AMD does not recommend using STIBP, but recommends using IBPB, so disabling
IBPB because of missing STIBP goes directly against AMD's advice:
https://developer.amd.com/wp-content/resources/Architecture_Guidelines_Update_Indirect_Branch_Control.pdf
Similarly, enhanced IBRS is designed to protect cross-core BTB poisoning
and BTB-poisoning attacks from user space against kernel (and
BTB-poisoning attacks from guest against hypervisor), it is not designed
to prevent cross-process (or cross-VM) BTB poisoning between processes (or
VMs) running on the same core. Therefore, even with enhanced IBRS it is
necessary to flush the BTB during context-switches, so there is no reason
to force disable IBPB when enhanced IBRS is available.
Enable the prctl control of IBPB even when STIBP is unavailable or enhanced
IBRS is available.
Fixes: 7cc765a67d8e ("x86/speculation: Enable prctl mode for spectre_v2_user")
Signed-off-by: Anthony Steinhauser <asteinhauser@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 20c3a2c33e9fdc82e9e8e8d2a6445b3256d20191 ]
Different AMD processors may have different implementations of STIBP.
When STIBP is conditionally enabled, some implementations would benefit
from having STIBP always on instead of toggling the STIBP bit through MSR
writes. This preference is advertised through a CPUID feature bit.
When conditional STIBP support is requested at boot and the CPU advertises
STIBP always-on mode as preferred, switch to STIBP "on" support. To show
that this transition has occurred, create a new spectre_v2_user_mitigation
value and a new spectre_v2_user_strings message. The new mitigation value
is used in spectre_v2_user_select_mitigation() to print the new mitigation
message as well as to return a new string from stibp_state().
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20181213230352.6937.74943.stgit@tlendack-t1.amdoffice.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit aa77bfb354c495fc4361199e63fc5765b9e1e783 ]
STIBP stands for Single Thread Indirect Branch Predictors. The acronym,
however, can be easily mis-spelled as STIPB. It is perhaps due to the
presence of another related term - IBPB (Indirect Branch Predictor
Barrier).
Fix the mis-spelling in the code.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1544039368-9009-1-git-send-email-longman@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 140fd4ac78d385e6c8e6a5757585f6c707085f87 upstream.
On MacBook6,1 reboot would hang unless parameter reboot=pci is added.
Make it automatic.
Signed-off-by: Hill Ma <maahiuzeon@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200425200641.GA1554@cslab.localdomain
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
