Add a helper, mmu_alloc_root(), to consolidate the allocation of a root
shadow page, which has the same basic mechanics for all flavors of TDP
and shadow paging.
Note, __pa(sp->spt) doesn't need to be protected by mmu_lock, sp->spt
points at a kernel page.
No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200428023714.31923-1-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace KVM's PT_PAGE_TABLE_LEVEL, PT_DIRECTORY_LEVEL and PT_PDPE_LEVEL
with the kernel's PG_LEVEL_4K, PG_LEVEL_2M and PG_LEVEL_1G. KVM's
enums are borderline impossible to remember and result in code that is
visually difficult to audit, e.g.
if (!enable_ept)
ept_lpage_level = 0;
else if (cpu_has_vmx_ept_1g_page())
ept_lpage_level = PT_PDPE_LEVEL;
else if (cpu_has_vmx_ept_2m_page())
ept_lpage_level = PT_DIRECTORY_LEVEL;
else
ept_lpage_level = PT_PAGE_TABLE_LEVEL;
versus
if (!enable_ept)
ept_lpage_level = 0;
else if (cpu_has_vmx_ept_1g_page())
ept_lpage_level = PG_LEVEL_1G;
else if (cpu_has_vmx_ept_2m_page())
ept_lpage_level = PG_LEVEL_2M;
else
ept_lpage_level = PG_LEVEL_4K;
No functional change intended.
Suggested-by: Barret Rhoden <brho@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200428005422.4235-4-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Change the PSE hugepage handling in walk_addr_generic() to fire on any
page level greater than PT_PAGE_TABLE_LEVEL, a.k.a. PG_LEVEL_4K. PSE
paging only has two levels, so "== 2" and "> 1" are functionally the
same, i.e. this is a nop.
A future patch will drop KVM's PT_*_LEVEL enums in favor of the kernel's
PG_LEVEL_* enums, at which point "walker->level == PG_LEVEL_2M" is
semantically incorrect (though still functionally ok).
No functional change intended.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200428005422.4235-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use an enum for passing around the failure code for a failed VM-Enter
that results in VM-Exit to provide a level of indirection from the final
resting place of the failure code, vmcs.EXIT_QUALIFICATION. The exit
qualification field is an unsigned long, e.g. passing around
'u32 exit_qual' throws up red flags as it suggests KVM may be dropping
bits when reporting errors to L1. This is a red herring because the
only defined failure codes are 0, 2, 3, and 4, i.e. don't come remotely
close to overflowing a u32.
Setting vmcs.EXIT_QUALIFICATION on entry failure is further complicated
by the MSR load list, which returns the (1-based) entry that failed, and
the number of MSRs to load is a 32-bit VMCS field. At first blush, it
would appear that overflowing a u32 is possible, but the number of MSRs
that can be loaded is hardcapped at 4096 (limited by MSR_IA32_VMX_MISC).
In other words, there are two completely disparate types of data that
eventually get stuffed into vmcs.EXIT_QUALIFICATION, neither of which is
an 'unsigned long' in nature. This was presumably the reasoning for
switching to 'u32' when the related code was refactored in commit
ca0bde28f2 ("kvm: nVMX: Split VMCS checks from nested_vmx_run()").
Using an enum for the failure code addresses the technically-possible-
but-will-never-happen scenario where Intel defines a failure code that
doesn't fit in a 32-bit integer. The enum variables and values will
either be automatically sized (gcc 5.4 behavior) or be subjected to some
combination of truncation. The former case will simply work, while the
latter will trigger a compile-time warning unless the compiler is being
particularly unhelpful.
Separating the failure code from the failed MSR entry allows for
disassociating both from vmcs.EXIT_QUALIFICATION, which avoids the
conundrum where KVM has to choose between 'u32 exit_qual' and tracking
values as 'unsigned long' that have no business being tracked as such.
To cement the split, set vmcs12->exit_qualification directly from the
entry error code or failed MSR index instead of bouncing through a local
variable.
Opportunistically rename the variables in load_vmcs12_host_state() and
vmx_set_nested_state() to call out that they're ignored, set exit_reason
on demand on nested VM-Enter failure, and add a comment in
nested_vmx_load_msr() to call out that returning 'i + 1' can't wrap.
No functional change intended.
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Jim Mattson <jmattson@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200511220529.11402-1-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This change adds per-CPU shadow call stacks for the SDEI handler.
Similarly to how the kernel stacks are handled, we add separate shadow
stacks for normal and critical events.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: James Morse <james.morse@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
If we detect a corrupted x18, restore the register before jumping back
to potentially SCS instrumented code. This is safe, because the wrapper
is called with preemption disabled and a separate shadow stack is used
for interrupt handling.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Reserve the x18 register from general allocation when SCS is enabled,
because the compiler uses the register to store the current task's
shadow stack pointer. Note that all external kernel modules must also be
compiled with -ffixed-x18 if the kernel has SCS enabled.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
The graph tracer hooks returns by modifying frame records on the
(regular) stack, but with SCS the return address is taken from the
shadow stack, and the value in the frame record has no effect. As we
don't currently have a mechanism to determine the corresponding slot
on the shadow stack (and to pass this through the ftrace
infrastructure), for now let's disable SCS when the graph tracer is
enabled.
With SCS the return address is taken from the shadow stack and the
value in the frame record has no effect. The mcount based graph tracer
hooks returns by modifying frame records on the (regular) stack, and
thus is not compatible. The patchable-function-entry graph tracer
used for DYNAMIC_FTRACE_WITH_REGS modifies the LR before it is saved
to the shadow stack, and is compatible.
Modifying the mcount based graph tracer to work with SCS would require
a mechanism to determine the corresponding slot on the shadow stack
(and to pass this through the ftrace infrastructure), and we expect
that everyone will eventually move to the patchable-function-entry
based graph tracer anyway, so for now let's disable SCS when the
mcount-based graph tracer is enabled.
SCS and patchable-function-entry are both supported from LLVM 10.x.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
This change adds generic support for Clang's Shadow Call Stack,
which uses a shadow stack to protect return addresses from being
overwritten by an attacker. Details are available here:
https://clang.llvm.org/docs/ShadowCallStack.html
Note that security guarantees in the kernel differ from the ones
documented for user space. The kernel must store addresses of
shadow stacks in memory, which means an attacker capable reading
and writing arbitrary memory may be able to locate them and hijack
control flow by modifying the stacks.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
[will: Numerous cosmetic changes]
Signed-off-by: Will Deacon <will@kernel.org>
Fix the assigned-clock-parents to higher frequency clock to avoid h264
encode timeout:
[ 134.763465] mtk_vpu 10020000.vpu: vpu ipi 4 ack time out !
[ 134.769008] [MTK_VCODEC][ERROR][18]: vpu_enc_send_msg() vpu_ipi_send msg_id c002 len 32 fail -5
[ 134.777707] [MTK_VCODEC][ERROR][18]: vpu_enc_encode() AP_IPIMSG_ENC_ENCODE 0 fail
venc_sel is the clock used by h264 encoder, and venclt_sel is the clock
used by vp8 encoder. Assign venc_sel to vcodecpll_ck and venclt_sel to
vcodecpll_370p5.
vcodecpll 1482000000
vcodecpll_ck 494000000
venc_sel 494000000
...
vcodecpll_370p5 370500000
venclt_sel 370500000
Fixes: fbbad0287c ("arm64: dts: Using standard CCF interface to set vcodec clk")
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Link: https://lore.kernel.org/r/20200504124442.208004-1-hsinyi@chromium.org
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Given the legacy bpf_probe_read{,str}() BPF helpers are broken on archs
with overlapping address ranges, we should really take the next step to
disable them from BPF use there.
To generally fix the situation, we've recently added new helper variants
bpf_probe_read_{user,kernel}() and bpf_probe_read_{user,kernel}_str().
For details on them, see 6ae08ae3de ("bpf: Add probe_read_{user, kernel}
and probe_read_{user,kernel}_str helpers").
Given bpf_probe_read{,str}() have been around for ~5 years by now, there
are plenty of users at least on x86 still relying on them today, so we
cannot remove them entirely w/o breaking the BPF tracing ecosystem.
However, their use should be restricted to archs with non-overlapping
address ranges where they are working in their current form. Therefore,
move this behind a CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE and
have x86, arm64, arm select it (other archs supporting it can follow-up
on it as well).
For the remaining archs, they can workaround easily by relying on the
feature probe from bpftool which spills out defines that can be used out
of BPF C code to implement the drop-in replacement for old/new kernels
via: bpftool feature probe macro
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/bpf/20200515101118.6508-2-daniel@iogearbox.net
Users can choose which flexcom function to use. Describe the I2C
Flexcom0 function. Add alias for the i2c2 node in order to not rely
on probe order for the i2c device numbering. The sama5d2 SoC has
two dedicated i2c buses and five flexcoms that can function as i2c.
The i2c0 and i2c1 aliases are kept for the dedicated i2c buses,
the i2c flexcom functions can be numbered in order starting from i2c2.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20200514050301.147442-16-tudor.ambarus@microchip.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Device aliases are board-specific, if needed one should define them
in board dts rather than in the SoC dtsi. If an alias from the SoC
dtsi is addressed by a driver that does not use any of the of_alias*()
methods, we can drop it. This is the case for the i2s aliases, drop
them. tcb aliases point to nodes that are not enabled in any of the
sama5d2 based platforms. atmel_tclib.c is scheduled to go away, any
board using that alias is already broken, so get rid of the tcb aliases
too.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20200514050301.147442-14-tudor.ambarus@microchip.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The Flexcom IP is part of the sama5d2 SoC. Move the flx0 node together
with its function definitions in sama5d2.dtsi. Boards will just fill
the pins and enable the desired functions.
There is a single functional change in this patch. With the move of the
flx0 uart5 definition in the SoC dtsi, the uart5 from
at91-sama5d27_wlsom1_ek.dts inherits the following optional property:
atmel,fifo-size = <32>;
This particular change was tested by Codrin.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Tested-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Link: https://lore.kernel.org/r/20200514050301.147442-7-tudor.ambarus@microchip.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Moritz writes:
FPGA Manager changes for 5.8
Here's the first set of changes for the 5.8-rc1 merge window.
Dominic's change adds support for accessing AFU regions with gdb.
Gustavo's change is a cleanup patch regarding variable lenght arrays.
Richard's changes update dt-bindings and add support for stratix and agilex.
Sergiu's changes update spi transfers with the new delay field.
Xu's change addresses an issue with a wrong return value.
Shubhrajyoti's change makes the Zynq FPGA driver return -EPROBE_DEFER on
check of devm_clk_get failure.
Xu's change for DFL enables multiple opens.
All of these patches have been reviewed, have appropriate Acked-by's and
have been in the last few linux-next releases without issues.
Signed-off-by: Moritz Fischer <mdf@kernel.org>
* tag 'fpga-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mdf/linux-fpga:
fpga: dfl: afu: support debug access to memory-mapped afu regions
fpga: dfl.h: Replace zero-length array with flexible-array member
arm64: dts: agilex: correct service layer driver's compatible value
dt-bindings, firmware: add compatible value Intel Stratix10 service layer binding
fpga: stratix10-soc: add compatible property value for intel agilex
arm64: dts: agilex: correct FPGA manager driver's compatible value
dt-bindings: fpga: add compatible value to Stratix10 SoC FPGA manager binding
fpga: machxo2-spi: Use new structure for SPI transfer delays
fpga: ice40-spi: Use new structure for SPI transfer delays
fpga: dfl: support multiple opens on feature device node.
... or the odyssey of trying to disable the stack protector for the
function which generates the stack canary value.
The whole story started with Sergei reporting a boot crash with a kernel
built with gcc-10:
Kernel panic — not syncing: stack-protector: Kernel stack is corrupted in: start_secondary
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc5—00235—gfffb08b37df9 #139
Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77M—D3H, BIOS F12 11/14/2013
Call Trace:
dump_stack
panic
? start_secondary
__stack_chk_fail
start_secondary
secondary_startup_64
-—-[ end Kernel panic — not syncing: stack—protector: Kernel stack is corrupted in: start_secondary
This happens because gcc-10 tail-call optimizes the last function call
in start_secondary() - cpu_startup_entry() - and thus emits a stack
canary check which fails because the canary value changes after the
boot_init_stack_canary() call.
To fix that, the initial attempt was to mark the one function which
generates the stack canary with:
__attribute__((optimize("-fno-stack-protector"))) ... start_secondary(void *unused)
however, using the optimize attribute doesn't work cumulatively
as the attribute does not add to but rather replaces previously
supplied optimization options - roughly all -fxxx options.
The key one among them being -fno-omit-frame-pointer and thus leading to
not present frame pointer - frame pointer which the kernel needs.
The next attempt to prevent compilers from tail-call optimizing
the last function call cpu_startup_entry(), shy of carving out
start_secondary() into a separate compilation unit and building it with
-fno-stack-protector, was to add an empty asm("").
This current solution was short and sweet, and reportedly, is supported
by both compilers but we didn't get very far this time: future (LTO?)
optimization passes could potentially eliminate this, which leads us
to the third attempt: having an actual memory barrier there which the
compiler cannot ignore or move around etc.
That should hold for a long time, but hey we said that about the other
two solutions too so...
Reported-by: Sergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Kalle Valo <kvalo@codeaurora.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200314164451.346497-1-slyfox@gentoo.org
Small fixes to make these DTs compliant with the adi,adv7511w and
adi,adv7513 bindings:
r8a7745-iwg22d-sodimm-dbhd-ca.dts
r8a7790-lager.dts
r8a7790-stout.dts
r8a7791-koelsch.dts
r8a7791-porter.dts
r8a7792-blanche.dts
r8a7793-gose.dts
r8a7794-silk.dts:
Remove the adi,input-style and adi,input-justification properties.
r8a7792-wheat.dts:
Reorder the I2C slave addresses of hdmi@3d and hdmi@39 and remove
the adi,input-style and adi,input-justification properties.
Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20200511110611.3142-3-ricardo.canuelo@collabora.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Small fixes to make these DTs compliant with the adi,adv7511w binding.
r8a77970-eagle.dts,
r8a77970-v3msk.dts,
r8a77980-condor.dts,
r8a77980-v3hsk.dts,
r8a77990-ebisu.dts:
Remove the adi,input-style and adi,input-justification properties.
r8a77995-draak.dts:
Reorder the I2C slave addresses of the hdmi-encoder@39 node and
remove the adi,input-style and adi,input-justification properties.
Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20200511110611.3142-2-ricardo.canuelo@collabora.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
The unwind_state 'error' field is used to inform the reliable unwinding
code that the stack trace can't be trusted. Set this field for all
errors in __unwind_start().
Also, move the zeroing out of the unwind_state struct to before the ORC
table initialization check, to prevent the caller from reading
uninitialized data if the ORC table is corrupted.
Fixes: af085d9084 ("stacktrace/x86: add function for detecting reliable stack traces")
Fixes: d3a0910401 ("x86/unwinder/orc: Dont bail on stack overflow")
Fixes: 98d0c8ebf7 ("x86/unwind/orc: Prevent unwinding before ORC initialization")
Reported-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/d6ac7215a84ca92b895fdd2e1aa546729417e6e6.1589487277.git.jpoimboe@redhat.com
