Commit graph

205,316 commits

Author SHA1 Message Date
Linus Torvalds
a367a31de2 x86/resctl: fix scheduler confusion with 'current'
commit 7fef099702 upstream.

The implementation of 'current' on x86 is very intentionally special: it
is a very common thing to look up, and it uses 'this_cpu_read_stable()'
to get the current thread pointer efficiently from per-cpu storage.

And the keyword in there is 'stable': the current thread pointer never
changes as far as a single thread is concerned.  Even if when a thread
is preempted, or moved to another CPU, or even across an explicit call
'schedule()' that thread will still have the same value for 'current'.

It is, after all, the kernel base pointer to thread-local storage.
That's why it's stable to begin with, but it's also why it's important
enough that we have that special 'this_cpu_read_stable()' access for it.

So this is all done very intentionally to allow the compiler to treat
'current' as a value that never visibly changes, so that the compiler
can do CSE and combine multiple different 'current' accesses into one.

However, there is obviously one very special situation when the
currently running thread does actually change: inside the scheduler
itself.

So the scheduler code paths are special, and do not have a 'current'
thread at all.  Instead there are _two_ threads: the previous and the
next thread - typically called 'prev' and 'next' (or prev_p/next_p)
internally.

So this is all actually quite straightforward and simple, and not all
that complicated.

Except for when you then have special code that is run in scheduler
context, that code then has to be aware that 'current' isn't really a
valid thing.  Did you mean 'prev'? Did you mean 'next'?

In fact, even if then look at the code, and you use 'current' after the
new value has been assigned to the percpu variable, we have explicitly
told the compiler that 'current' is magical and always stable.  So the
compiler is quite free to use an older (or newer) value of 'current',
and the actual assignment to the percpu storage is not relevant even if
it might look that way.

Which is exactly what happened in the resctl code, that blithely used
'current' in '__resctrl_sched_in()' when it really wanted the new
process state (as implied by the name: we're scheduling 'into' that new
resctl state).  And clang would end up just using the old thread pointer
value at least in some configurations.

This could have happened with gcc too, and purely depends on random
compiler details.  Clang just seems to have been more aggressive about
moving the read of the per-cpu current_task pointer around.

The fix is trivial: just make the resctl code adhere to the scheduler
rules of using the prev/next thread pointer explicitly, instead of using
'current' in a situation where it just wasn't valid.

That same code is then also used outside of the scheduler context (when
a thread resctl state is explicitly changed), and then we will just pass
in 'current' as that pointer, of course.  There is no ambiguity in that
case.

The fix may be trivial, but noticing and figuring out what went wrong
was not.  The credit for that goes to Stephane Eranian.

Reported-by: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/lkml/20230303231133.1486085-1-eranian@google.com/
Link: https://lore.kernel.org/lkml/alpine.LFD.2.01.0908011214330.3304@localhost.localdomain/
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Stephane Eranian <eranian@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-11 13:50:47 +01:00
Jakub Kicinski
c2e4ac2ff9 eth: fealnx: bring back this old driver
commit 8f14820801 upstream.

This reverts commit d5e2d038db.

We have a report of this chip being used on a

  SURECOM EP-320X-S 100/10M Ethernet PCI Adapter

which could still have been purchased in some parts
of the world 3 years ago.

Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217151
Fixes: d5e2d038db ("eth: fealnx: delete the driver for Myson MTD-800")
Link: https://lore.kernel.org/r/20230307171930.4008454-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-11 13:50:46 +01:00
Krzysztof Kozlowski
a2f09b491b ARM: dts: spear320-hmi: correct STMPE GPIO compatible
[ Upstream commit 33a0c1b850 ]

The compatible is st,stmpe-gpio.

Fixes: e2eb69183e ("ARM: SPEAr320: DT: Add SPEAr 320 HMI board support")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20230225162237.40242-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 13:50:34 +01:00
Eddie James
16ff58cf5f ARM: dts: aspeed: p10bmc: Update battery node name
[ Upstream commit a8cef541dd ]

The ADC sensor for the battery needs to be named "iio-hwmon" for
compatibility with user space applications.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20230202152759.67069-1-eajames@linux.ibm.com
Fixes: bf1914e2cf ("ARM: dts: aspeed: p10bmc: Fix ADC iio-hwmon battery node name")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20230221003352.1218797-1-joel@jms.id.au
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 13:50:34 +01:00
Benjamin Berg
a301531449 um: virt-pci: properly remove PCI device from bus
[ Upstream commit 339b84dcd7 ]

Triggering a bus rescan will not cause the PCI device to be removed. It
is required to explicitly stop and remove the device from the bus.

Fixes: 68f5d3f3b6 ("um: add PCI over virtio emulation driver")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 13:50:28 +01:00
Benjamin Berg
bb2d169e63 um: virtio_uml: move device breaking into workqueue
[ Upstream commit abdeb4fa5e ]

We should not be calling virtio_break_device from an IRQ context.
Move breaking the device into the workqueue so that it is done from
a reasonable context.

Fixes: af9fb41ed3 ("um: virtio_uml: Fix broken device handling in time-travel")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 13:50:28 +01:00
Benjamin Berg
9f63b3340a um: virtio_uml: mark device as unregistered when breaking it
[ Upstream commit 8e9cd85139 ]

Mark the device as not registered anymore when scheduling the work to
remove it. Otherwise we could end up scheduling the work multiple times
in a row, including scheduling it while it is already running.

Fixes: af9fb41ed3 ("um: virtio_uml: Fix broken device handling in time-travel")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 13:50:28 +01:00
Benjamin Berg
a6fbcf92f1 um: virtio_uml: free command if adding to virtqueue failed
[ Upstream commit 8a6ca54364 ]

If adding the command fails (i.e. the virtqueue is broken) then free it
again if the function allocated a new buffer for it.

Fixes: 68f5d3f3b6 ("um: add PCI over virtio emulation driver")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 13:50:28 +01:00
Ammar Faizi
dc23256a0b x86: um: vdso: Add '%rcx' and '%r11' to the syscall clobber list
[ Upstream commit 5541992e51 ]

The 'syscall' instruction clobbers '%rcx' and '%r11', but they are not
listed in the inline Assembly that performs the syscall instruction.

No real bug is found. It wasn't buggy by luck because '%rcx' and '%r11'
are caller-saved registers, and not used in the functions, and the
functions are never inlined.

Add them to the clobber list for code correctness.

Fixes: f1c2bb8b99 ("um: implement a x86_64 vDSO")
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 13:50:27 +01:00
Xiang Yang
634a9c139c um: vector: Fix memory leak in vector_config
[ Upstream commit 8f88c73afe ]

If the return value of the uml_parse_vector_ifspec function is NULL,
we should call kfree(params) to prevent memory leak.

Fixes: 49da7e64f3 ("High Performance UML Vector Network Driver")
Signed-off-by: Xiang Yang <xiangyang3@huawei.com>
Acked-By: Anton Ivanov <anton.ivanov@kot-begemot.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 13:50:23 +01:00
H. Nikolaus Schaller
5475b05b5f MIPS: DTS: CI20: fix otg power gpio
commit 0cb4228f6c upstream.

According to schematics it is PF15 and not PF14 (MIC_SW_EN).
Seems as if it was hidden and not noticed during testing since
there is no sound DT node.

Fixes: 158c774d3c ("MIPS: Ingenic: Add missing nodes for Ingenic SoCs and boards.")
Cc: stable@vger.kernel.org
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Acked-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:53 +01:00
Guo Ren
8a0fc187e9 riscv: ftrace: Reduce the detour code size to half
commit 6724a76cff upstream.

Use a temporary register to reduce the size of detour code from 16 bytes to
8 bytes. The previous implementation is from 'commit afc76b8b80 ("riscv:
Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT")'.

Before the patch:
<func_prolog>:
 0: REG_S  ra, -SZREG(sp)
 4: auipc  ra, ?
 8: jalr   ?(ra)
12: REG_L  ra, -SZREG(sp)
 (func_boddy)

After the patch:
<func_prolog>:
 0: auipc  t0, ?
 4: jalr   t0, ?(t0)
 (func_boddy)

This patch not just reduces the size of detour code, but also fixes an
important issue:

An Ftrace callback registered with FTRACE_OPS_FL_IPMODIFY flag can
actually change the instruction pointer, e.g. to "replace" the given
kernel function with a new one, which is needed for livepatching, etc.

In this case, the trampoline (ftrace_regs_caller) would not return to
<func_prolog+12> but would rather jump to the new function. So, "REG_L
ra, -SZREG(sp)" would not run and the original return address would not
be restored. The kernel is likely to hang or crash as a result.

This can be easily demonstrated if one tries to "replace", say,
cmdline_proc_show() with a new function with the same signature using
instruction_pointer_set(&fregs->regs, new_func_addr) in the Ftrace
callback.

Link: https://lore.kernel.org/linux-riscv/20221122075440.1165172-1-suagrfillet@gmail.com/
Link: https://lore.kernel.org/linux-riscv/d7d5730b-ebef-68e5-5046-e763e1ee6164@yadro.com/
Co-developed-by: Song Shuai <suagrfillet@gmail.com>
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Evgenii Shatokhin <e.shatokhin@yadro.com>
Reviewed-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Link: https://lore.kernel.org/r/20230112090603.1295340-4-guoren@kernel.org
Cc: stable@vger.kernel.org
Fixes: 10626c32e3 ("riscv/ftrace: Add basic support")
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:53 +01:00
Guo Ren
10509799f4 riscv: ftrace: Remove wasted nops for !RISCV_ISA_C
commit 409c8fb20c upstream.

When CONFIG_RISCV_ISA_C=n, -fpatchable-function-entry=8 would generate
more nops than we expect. Because it treat nop opcode as 0x00000013
instead of 0x0001.

Dump of assembler code for function dw_pcie_free_msi:
   0xffffffff806fce94 <+0>:     sd      ra,-8(sp)
   0xffffffff806fce98 <+4>:     auipc   ra,0xff90f
   0xffffffff806fce9c <+8>:     jalr    -684(ra) # 0xffffffff8000bbec
<ftrace_caller>
   0xffffffff806fcea0 <+12>:    ld      ra,-8(sp)
   0xffffffff806fcea4 <+16>:    nop /* wasted */
   0xffffffff806fcea8 <+20>:    nop /* wasted */
   0xffffffff806fceac <+24>:    nop /* wasted */
   0xffffffff806fceb0 <+28>:    nop /* wasted */
   0xffffffff806fceb4 <+0>:     addi    sp,sp,-48
   0xffffffff806fceb8 <+4>:     sd      s0,32(sp)
   0xffffffff806fcebc <+8>:     sd      s1,24(sp)
   0xffffffff806fcec0 <+12>:    sd      s2,16(sp)
   0xffffffff806fcec4 <+16>:    sd      s3,8(sp)
   0xffffffff806fcec8 <+20>:    sd      ra,40(sp)
   0xffffffff806fcecc <+24>:    addi    s0,sp,48

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230112090603.1295340-3-guoren@kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:53 +01:00
Björn Töpel
ed157545d0 riscv, mm: Perform BPF exhandler fixup on page fault
commit 416721ff05 upstream.

Commit 21855cac82 ("riscv/mm: Prevent kernel module to access user
memory without uaccess routines") added early exits/deaths for page
faults stemming from accesses to user-space without using proper
uaccess routines (where sstatus.SUM is set).

Unfortunatly, this is too strict for some BPF programs, which relies
on BPF exhandler fixups. These BPF programs loads "BTF pointers". A
BTF pointers could either be a valid kernel pointer or NULL, but not a
userspace address.

Resolve the problem by calling the fixup handler in the early exit
path.

Fixes: 21855cac82 ("riscv/mm: Prevent kernel module to access user memory without uaccess routines")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230214162515.184827-1-bjorn@kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:53 +01:00
Andy Chiu
20a7510e78 riscv: ftrace: Fixup panic by disabling preemption
commit 8547649981 upstream.

In RISCV, we must use an AUIPC + JALR pair to encode an immediate,
forming a jump that jumps to an address over 4K. This may cause errors
if we want to enable kernel preemption and remove dependency from
patching code with stop_machine(). For example, if a task was switched
out on auipc. And, if we changed the ftrace function before it was
switched back, then it would jump to an address that has updated 11:0
bits mixing with previous XLEN:12 part.

p: patched area performed by dynamic ftrace
ftrace_prologue:
p|      REG_S   ra, -SZREG(sp)
p|      auipc   ra, 0x? ------------> preempted
					...
				change ftrace function
					...
p|      jalr    -?(ra) <------------- switched back
p|      REG_L   ra, -SZREG(sp)
func:
	xxx
	ret

Fixes: afc76b8b80 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT")
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230112090603.1295340-2-guoren@kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:53 +01:00
Andy Chiu
60312d09c6 riscv: jump_label: Fixup unaligned arch_static_branch function
commit 9ddfc3cd80 upstream.

Runtime code patching must be done at a naturally aligned address, or we
may execute on a partial instruction.

We have encountered problems traced back to static jump functions during
the test. We switched the tracer randomly for every 1~5 seconds on a
dual-core QEMU setup and found the kernel sucking at a static branch
where it jumps to itself.

The reason is that the static branch was 2-byte but not 4-byte aligned.
Then, the kernel would patch the instruction, either J or NOP, with two
half-word stores if the machine does not have efficient unaligned
accesses. Thus, moments exist where half of the NOP mixes with the other
half of the J when transitioning the branch. In our particular case, on
a little-endian machine, the upper half of the NOP was mixed with the
lower part of the J when enabling the branch, resulting in a jump that
jumped to itself. Conversely, it would result in a HINT instruction when
disabling the branch, but it might not be observable.

ARM64 does not have this problem since all instructions must be 4-byte
aligned.

Fixes: ebc00dde8a ("riscv: Add jump-label implementation")
Link: https://lore.kernel.org/linux-riscv/20220913094252.3555240-6-andy.chiu@sifive.com/
Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230206090440.1255001-1-guoren@kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:53 +01:00
Sergey Matyukevich
8ef3d23d4d riscv: mm: fix regression due to update_mmu_cache change
commit b49f700668 upstream.

This is a partial revert of the commit 4bd1d80efb ("riscv: mm: notify
remote harts about mmu cache updates"). Original commit included two
loosely related changes serving the same purpose of fixing stale TLB
entries causing user-space application crash:
- introduce deferred per-ASID TLB flush for CPUs not running the task
- switch to per-ASID TLB flush on all CPUs running the task in update_mmu_cache

According to report and discussion in [1], the second part caused a
regression on Renesas RZ/Five SoC. For now restore the old behavior
of the update_mmu_cache.

[1] https://lore.kernel.org/linux-riscv/20220829205219.283543-1-geomatsi@gmail.com/

Fixes: 4bd1d80efb ("riscv: mm: notify remote harts about mmu cache updates")
Reported-by: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com>
Link: trailer, so that it can be parsed with git's trailer functionality?
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230129211818.686557-1-geomatsi@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:52 +01:00
Mattias Nissler
424818a16b riscv: Avoid enabling interrupts in die()
commit 130aee3fd9 upstream.

While working on something else, I noticed that the kernel would start
accepting interrupts again after crashing in an interrupt handler. Since
the kernel is already in inconsistent state, enabling interrupts is
dangerous and opens up risk of kernel state deteriorating further.
Interrupts do get enabled via what looks like an unintended side effect of
spin_unlock_irq, so switch to the more cautious
spin_lock_irqsave/spin_unlock_irqrestore instead.

Fixes: 76d2a0493a ("RISC-V: Init and Halt Code")
Signed-off-by: Mattias Nissler <mnissler@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/r/20230215144828.3370316-1-mnissler@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:52 +01:00
Conor Dooley
fec6331a42 RISC-V: add a spin_shadow_stack declaration
commit eb9be8310c upstream.

The patchwork automation reported a sparse complaint that
spin_shadow_stack was not declared and should be static:
../arch/riscv/kernel/traps.c:335:15: warning: symbol 'spin_shadow_stack' was not declared. Should it be static?

However, this is used in entry.S and therefore shouldn't be static.
The same applies to the shadow_stack that this pseudo spinlock is
trying to protect, so do like its charge and add a declaration to
thread_info.h

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Fixes: 7e1864332f ("riscv: fix race when vmap stack overflow")
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230210185945.915806-1-conor@kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:52 +01:00
Elvira Khabirova
8263e14a99 mips: fix syscall_get_nr
commit 85cc91e2ba upstream.

The implementation of syscall_get_nr on mips used to ignore the task
argument and return the syscall number of the calling thread instead of
the target thread.

The bug was exposed to user space by commit 201766a20e ("ptrace: add
PTRACE_GET_SYSCALL_INFO request") and detected by strace test suite.

Link: https://github.com/strace/strace/issues/235
Fixes: c2d9f17757 ("MIPS: Fix syscall_get_nr for the syscall exit tracing.")
Cc: <stable@vger.kernel.org> # v3.19+
Co-developed-by: Dmitry V. Levin <ldv@strace.io>
Signed-off-by: Dmitry V. Levin <ldv@strace.io>
Signed-off-by: Elvira Khabirova <lineprinter0@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:48 +01:00
Al Viro
16850c9cec alpha: fix FEN fault handling
commit 977a300954 upstream.

Type 3 instruction fault (FPU insn with FPU disabled) is handled
by quietly enabling FPU and returning.  Which is fine, except that
we need to do that both for fault in userland and in the kernel;
the latter *can* legitimately happen - all it takes is this:

.global _start
_start:
        call_pal 0xae
	lda $0, 0
	ldq $0, 0($0)

- call_pal CLRFEN to clear "FPU enabled" flag and arrange for
a signal delivery (SIGSEGV in this case).

Fixed by moving the handling of type 3 into the common part of
do_entIF(), before we check for kernel vs. user mode.

Incidentally, the check for kernel mode is unidiomatic; the normal
way to do that is !user_mode(regs).  The difference is that
the open-coded variant treats any of bits 63..3 of regs->ps being
set as "it's user mode" while the normal approach is to check just
the bit 3.  PS is a 4-bit register and regs->ps always will have
bits 63..4 clear, so the open-coded variant here is actually equivalent
to !user_mode(regs).  Harder to follow, though...

Cc: stable@vger.kernel.org
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:48 +01:00
Peter Collingbourne
d1c9727ba8 arm64: Reset KASAN tag in copy_highpage with HW tags only
commit e74a684680 upstream.

During page migration, the copy_highpage function is used to copy the
page data to the target page. If the source page is a userspace page
with MTE tags, the KASAN tag of the target page must have the match-all
tag in order to avoid tag check faults during subsequent accesses to the
page by the kernel. However, the target page may have been allocated in
a number of ways, some of which will use the KASAN allocator and will
therefore end up setting the KASAN tag to a non-match-all tag. Therefore,
update the target page's KASAN tag to match the source page.

We ended up unintentionally fixing this issue as a result of a bad
merge conflict resolution between commit e059853d14 ("arm64: mte:
Fix/clarify the PG_mte_tagged semantics") and commit 20794545c1 ("arm64:
kasan: Revert "arm64: mte: reset the page tag in page->flags""), which
preserved a tag reset for PG_mte_tagged pages which was considered to be
unnecessary at the time. Because SW tags KASAN uses separate tag storage,
update the code to only reset the tags when HW tags KASAN is enabled.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/If303d8a709438d3ff5af5fd85706505830f52e0c
Reported-by: "Kuan-Ying Lee (李冠穎)" <Kuan-Ying.Lee@mediatek.com>
Cc: <stable@vger.kernel.org> # 6.1
Fixes: 20794545c1 ("arm64: kasan: Revert "arm64: mte: reset the page tag in page->flags"")
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20230215050911.1433132-1-pcc@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:47 +01:00
Catalin Marinas
1e614cc200 arm64: mm: hugetlb: Disable HUGETLB_PAGE_OPTIMIZE_VMEMMAP
commit 060a2c92d1 upstream.

Revert the HUGETLB_PAGE_FREE_VMEMMAP selection from commit 1e63ac088f
("arm64: mm: hugetlb: enable HUGETLB_PAGE_FREE_VMEMMAP for arm64") but
keep the flush_dcache_page() compound_head() change as it aligns with
the corresponding check in the __sync_icache_dcache() function.

The original config option was renamed in commit 47010c040d ("mm:
hugetlb_vmemmap: cleanup CONFIG_HUGETLB_PAGE_FREE_VMEMMAP*") to
HUGETLB_PAGE_OPTIMIZE_VMEMMAP and the flush_dcache_page() check was
further simplified by commit 2da1c30929 ("mm: hugetlb_vmemmap: delete
hugetlb_optimize_vmemmap_enabled()").

The reason for the revert is that the generic vmemmap_remap_pte()
function changes both the permissions (writeable to read-only) and the
output address (pfn) of the vmemmap ptes. This is deemed UNPREDICTABLE
by the Arm architecture without a break-before-make sequence (make the
PTE invalid, TLBI, write the new valid PTE). However, such sequence is
not possible since the vmemmap may be concurrently accessed by the
kernel. Disable the optimisation until a better solution is found.

Fixes: 1e63ac088f ("arm64: mm: hugetlb: enable HUGETLB_PAGE_FREE_VMEMMAP for arm64")
Cc: <stable@vger.kernel.org> # 5.19.x
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Will Deacon <will@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/Y9pZALdn3pKiJUeQ@arm.com
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20230222175232.540851-1-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:47 +01:00
Sudeep Holla
7521da2eb4 arm64: acpi: Fix possible memory leak of ffh_ctxt
commit 1b561d3949 upstream.

Allocated 'ffh_ctxt' memory leak is possible if the SMCCC version
and conduit checks fail and -EOPNOTSUPP is returned without freeing the
allocated memory.

Fix the same by moving the allocation after the SMCCC version and
conduit checks.

Fixes: 1d280ce099 ("arm64: Add architecture specific ACPI FFH Opregion callbacks")
Cc: <stable@vger.kernel.org> # 6.2.x
Cc: Will Deacon <will@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Suggested-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/202302191417.dAl9NuE8-lkp@intel.com/
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20230223135742.2952091-1-sudeep.holla@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:46 +01:00
Krzysztof Kozlowski
897e7a13a5 ARM: dts: exynos: correct TMU phandle in Odroid HC1
commit 2e3d0e20d8 upstream.

TMU node uses 0 as thermal-sensor-cells, thus thermal zone referencing
it must not have an argument to phandle.  This was not critical before,
but since rework of thermal Devicetree initialization in the
commit 3fd6d6e2b4 ("thermal/of: Rework the thermal device tree
initialization"), this leads to errors registering thermal zones other
than first one:

  thermal_sys: cpu0-thermal: Failed to read thermal-sensors cells: -2
  thermal_sys: Failed to find thermal zone for tmu id=0
  exynos-tmu 10064000.tmu: Failed to register sensor: -2
  exynos-tmu: probe of 10064000.tmu failed with error -2

Fixes: 1ac49427b5 ("ARM: dts: exynos: Add support for Hardkernel's Odroid HC1 board")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20230209105841.779596-5-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:46 +01:00
Krzysztof Kozlowski
1e2fb42a97 ARM: dts: exynos: correct TMU phandle in Odroid XU
commit 9372eca505 upstream.

TMU node uses 0 as thermal-sensor-cells, thus thermal zone referencing
it must not have an argument to phandle.  Since thermal-sensors property
is already defined in included exynosi5410.dtsi, drop it from
exynos5410-odroidxu.dts to fix the error and remoev redundancy.

Fixes: 88644b4c75 ("ARM: dts: exynos: Configure PWM, usb3503, PMIC and thermal on Odroid XU board")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20230209105841.779596-4-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:46 +01:00
Krzysztof Kozlowski
676c5672ab ARM: dts: exynos: correct TMU phandle in Exynos5250
commit 33e2c595e2 upstream.

TMU node uses 0 as thermal-sensor-cells, thus thermal zone referencing
it must not have an argument to phandle.

Cc: <stable@vger.kernel.org>
Fixes: 9843a22360 ("ARM: dts: Provide dt bindings identical for Exynos TMU")
Link: https://lore.kernel.org/r/20230209105841.779596-3-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:46 +01:00
Krzysztof Kozlowski
044a0326fc ARM: dts: exynos: correct TMU phandle in Odroid XU3 family
commit a3583e92d1 upstream.

TMU node uses 0 as thermal-sensor-cells, thus thermal zone referencing
it must not have an argument to phandle.  This was not critical before,
but since rework of thermal Devicetree initialization in the
commit 3fd6d6e2b4 ("thermal/of: Rework the thermal device tree
initialization"), this leads to errors registering thermal zones other
than first one:

  thermal_sys: cpu0-thermal: Failed to read thermal-sensors cells: -2
  thermal_sys: Failed to find thermal zone for tmu id=0
  exynos-tmu 10064000.tmu: Failed to register sensor: -2
  exynos-tmu: probe of 10064000.tmu failed with error -2

Fixes: f1722d7dd8 ("ARM: dts: Define default thermal-zones for exynos5422")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20230209105841.779596-6-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:46 +01:00
Krzysztof Kozlowski
360c3fdec7 ARM: dts: exynos: correct TMU phandle in Exynos4
commit 8e4505e617 upstream.

TMU node uses 0 as thermal-sensor-cells, thus thermal zone referencing
it must not have an argument to phandle.

Fixes: 328829a6ad ("ARM: dts: define default thermal-zones for exynos4")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20230209105841.779596-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:46 +01:00
Krzysztof Kozlowski
d77be13b9e ARM: dts: exynos: correct TMU phandle in Exynos4210
commit 408ab6786d upstream.

TMU node uses 0 as thermal-sensor-cells, thus thermal zone referencing
it must not have an argument to phandle.  Since thermal-sensors property is
already defined in included exynos4-cpu-thermal.dtsi, drop it from
exynos4210.dtsi to fix the error and remoev redundancy.

Fixes: 9843a22360 ("ARM: dts: Provide dt bindings identical for Exynos TMU")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20230209105841.779596-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:45 +01:00
Manivannan Sadhasivam
ad08f81f80 ARM: dts: qcom: sdx55: Add Qcom SMMU-500 as the fallback for IOMMU node
commit af4ab37754 upstream.

SDX55 uses the Qcom version of the SMMU-500 IP. So use "qcom,smmu-500"
compatible as the fallback to the SoC specific compatible.

Cc: <stable@vger.kernel.org> # 5.12
Fixes: a2bdfdfba2 ("ARM: dts: qcom: sdx55: Enable ARM SMMU")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230123131931.263024-3-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:45 +01:00
Manivannan Sadhasivam
8acd379b92 ARM: dts: qcom: sdx65: Add Qcom SMMU-500 as the fallback for IOMMU node
commit 157178a791 upstream.

SDX65 uses the Qcom version of the SMMU-500 IP. So use "qcom,smmu-500"
compatible as the fallback to the SoC specific compatible.

Cc: <stable@vger.kernel.org> # 5.19
Fixes: 98187f7b74 ("ARM: dts: qcom: sdx65: Enable ARM SMMU")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230123131931.263024-4-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:45 +01:00
KP Singh
ead3c8e54d x86/speculation: Allow enabling STIBP with legacy IBRS
commit 6921ed9049 upstream.

When plain IBRS is enabled (not enhanced IBRS), the logic in
spectre_v2_user_select_mitigation() determines that STIBP is not needed.

The IBRS bit implicitly protects against cross-thread branch target
injection. However, with legacy IBRS, the IBRS bit is cleared on
returning to userspace for performance reasons which leaves userspace
threads vulnerable to cross-thread branch target injection against which
STIBP protects.

Exclude IBRS from the spectre_v2_in_ibrs_mode() check to allow for
enabling STIBP (through seccomp/prctl() by default or always-on, if
selected by spectre_v2_user kernel cmdline parameter).

  [ bp: Massage. ]

Fixes: 7c693f54c8 ("x86/speculation: Add spectre_v2=ibrs option to support Kernel IBRS")
Reported-by: José Oliveira <joseloliveira11@gmail.com>
Reported-by: Rodrigo Branco <rodrigo@kernelhacking.com>
Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230220120127.1975241-1-kpsingh@kernel.org
Link: https://lore.kernel.org/r/20230221184908.2349578-1-kpsingh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:35 +01:00
Borislav Petkov (AMD)
eaf5dea1eb x86/microcode/AMD: Fix mixed steppings support
commit 7ff6edf4fe upstream.

The AMD side of the loader has always claimed to support mixed
steppings. But somewhere along the way, it broke that by assuming that
the cached patch blob is a single one instead of it being one per
*node*.

So turn it into a per-node one so that each node can stash the blob
relevant for it.

  [ NB: Fixes tag is not really the exactly correct one but it is good
    enough. ]

Fixes: fe055896c0 ("x86/microcode: Merge the early microcode loader")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org> # 2355370cd9 ("x86/microcode/amd: Remove load_microcode_amd()'s bsp parameter")
Cc: <stable@kernel.org> # a5ad92134b ("x86/microcode/AMD: Add a @cpu parameter to the reloading functions")
Link: https://lore.kernel.org/r/20230130161709.11615-4-bp@alien8.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:35 +01:00
Borislav Petkov (AMD)
4515c059e2 x86/microcode/AMD: Add a @cpu parameter to the reloading functions
commit a5ad92134b upstream.

Will be used in a subsequent change.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230130161709.11615-3-bp@alien8.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:35 +01:00
Borislav Petkov (AMD)
034cf5ae18 x86/microcode/amd: Remove load_microcode_amd()'s bsp parameter
commit 2355370cd9 upstream.

It is always the BSP.

No functional changes.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230130161709.11615-2-bp@alien8.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:35 +01:00
Yang Jihong
edcbb2800a x86/kprobes: Fix arch_check_optimized_kprobe check within optimized_kprobe range
commit f1c97a1b4e upstream.

When arch_prepare_optimized_kprobe calculating jump destination address,
it copies original instructions from jmp-optimized kprobe (see
__recover_optprobed_insn), and calculated based on length of original
instruction.

arch_check_optimized_kprobe does not check KPROBE_FLAG_OPTIMATED when
checking whether jmp-optimized kprobe exists.
As a result, setup_detour_execution may jump to a range that has been
overwritten by jump destination address, resulting in an inval opcode error.

For example, assume that register two kprobes whose addresses are
<func+9> and <func+11> in "func" function.
The original code of "func" function is as follows:

   0xffffffff816cb5e9 <+9>:     push   %r12
   0xffffffff816cb5eb <+11>:    xor    %r12d,%r12d
   0xffffffff816cb5ee <+14>:    test   %rdi,%rdi
   0xffffffff816cb5f1 <+17>:    setne  %r12b
   0xffffffff816cb5f5 <+21>:    push   %rbp

1.Register the kprobe for <func+11>, assume that is kp1, corresponding optimized_kprobe is op1.
  After the optimization, "func" code changes to:

   0xffffffff816cc079 <+9>:     push   %r12
   0xffffffff816cc07b <+11>:    jmp    0xffffffffa0210000
   0xffffffff816cc080 <+16>:    incl   0xf(%rcx)
   0xffffffff816cc083 <+19>:    xchg   %eax,%ebp
   0xffffffff816cc084 <+20>:    (bad)
   0xffffffff816cc085 <+21>:    push   %rbp

Now op1->flags == KPROBE_FLAG_OPTIMATED;

2. Register the kprobe for <func+9>, assume that is kp2, corresponding optimized_kprobe is op2.

register_kprobe(kp2)
  register_aggr_kprobe
    alloc_aggr_kprobe
      __prepare_optimized_kprobe
        arch_prepare_optimized_kprobe
          __recover_optprobed_insn    // copy original bytes from kp1->optinsn.copied_insn,
                                      // jump address = <func+14>

3. disable kp1:

disable_kprobe(kp1)
  __disable_kprobe
    ...
    if (p == orig_p || aggr_kprobe_disabled(orig_p)) {
      ret = disarm_kprobe(orig_p, true)       // add op1 in unoptimizing_list, not unoptimized
      orig_p->flags |= KPROBE_FLAG_DISABLED;  // op1->flags ==  KPROBE_FLAG_OPTIMATED | KPROBE_FLAG_DISABLED
    ...

4. unregister kp2
__unregister_kprobe_top
  ...
  if (!kprobe_disabled(ap) && !kprobes_all_disarmed) {
    optimize_kprobe(op)
      ...
      if (arch_check_optimized_kprobe(op) < 0) // because op1 has KPROBE_FLAG_DISABLED, here not return
        return;
      p->kp.flags |= KPROBE_FLAG_OPTIMIZED;   //  now op2 has KPROBE_FLAG_OPTIMIZED
  }

"func" code now is:

   0xffffffff816cc079 <+9>:     int3
   0xffffffff816cc07a <+10>:    push   %rsp
   0xffffffff816cc07b <+11>:    jmp    0xffffffffa0210000
   0xffffffff816cc080 <+16>:    incl   0xf(%rcx)
   0xffffffff816cc083 <+19>:    xchg   %eax,%ebp
   0xffffffff816cc084 <+20>:    (bad)
   0xffffffff816cc085 <+21>:    push   %rbp

5. if call "func", int3 handler call setup_detour_execution:

  if (p->flags & KPROBE_FLAG_OPTIMIZED) {
    ...
    regs->ip = (unsigned long)op->optinsn.insn + TMPL_END_IDX;
    ...
  }

The code for the destination address is

   0xffffffffa021072c:  push   %r12
   0xffffffffa021072e:  xor    %r12d,%r12d
   0xffffffffa0210731:  jmp    0xffffffff816cb5ee <func+14>

However, <func+14> is not a valid start instruction address. As a result, an error occurs.

Link: https://lore.kernel.org/all/20230216034247.32348-3-yangjihong1@huawei.com/

Fixes: f66c0447cc ("kprobes: Set unoptimized flag after unoptimizing code")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:35 +01:00
Yang Jihong
ce84d99832 x86/kprobes: Fix __recover_optprobed_insn check optimizing logic
commit 868a6fc0ca upstream.

Since the following commit:

  commit f66c0447cc ("kprobes: Set unoptimized flag after unoptimizing code")

modified the update timing of the KPROBE_FLAG_OPTIMIZED, a optimized_kprobe
may be in the optimizing or unoptimizing state when op.kp->flags
has KPROBE_FLAG_OPTIMIZED and op->list is not empty.

The __recover_optprobed_insn check logic is incorrect, a kprobe in the
unoptimizing state may be incorrectly determined as unoptimizing.
As a result, incorrect instructions are copied.

The optprobe_queued_unopt function needs to be exported for invoking in
arch directory.

Link: https://lore.kernel.org/all/20230216034247.32348-2-yangjihong1@huawei.com/

Fixes: f66c0447cc ("kprobes: Set unoptimized flag after unoptimizing code")
Cc: stable@vger.kernel.org
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:35 +01:00
Sean Christopherson
1698fda309 x86/reboot: Disable SVM, not just VMX, when stopping CPUs
commit a2b07fa7b9 upstream.

Disable SVM and more importantly force GIF=1 when halting a CPU or
rebooting the machine.  Similar to VMX, SVM allows software to block
INITs via CLGI, and thus can be problematic for a crash/reboot.  The
window for failure is smaller with SVM as INIT is only blocked while
GIF=0, i.e. between CLGI and STGI, but the window does exist.

Fixes: fba4f472b3 ("x86/reboot: Turn off KVM when halting a CPU")
Cc: stable@vger.kernel.org
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20221130233650.1404148-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:35 +01:00
Sean Christopherson
3a4afb7524 x86/reboot: Disable virtualization in an emergency if SVM is supported
commit d81f952aa6 upstream.

Disable SVM on all CPUs via NMI shootdown during an emergency reboot.
Like VMX, SVM can block INIT, e.g. if the emergency reboot is triggered
between CLGI and STGI, and thus can prevent bringing up other CPUs via
INIT-SIPI-SIPI.

Cc: stable@vger.kernel.org
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20221130233650.1404148-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:34 +01:00
Sean Christopherson
b01c0d04d3 x86/crash: Disable virt in core NMI crash handler to avoid double shootdown
commit 26044aff37 upstream.

Disable virtualization in crash_nmi_callback() and rework the
emergency_vmx_disable_all() path to do an NMI shootdown if and only if a
shootdown has not already occurred.   NMI crash shootdown fundamentally
can't support multiple invocations as responding CPUs are deliberately
put into halt state without unblocking NMIs.  But, the emergency reboot
path doesn't have any work of its own, it simply cares about disabling
virtualization, i.e. so long as a shootdown occurred, emergency reboot
doesn't care who initiated the shootdown, or when.

If "crash_kexec_post_notifiers" is specified on the kernel command line,
panic() will invoke crash_smp_send_stop() and result in a second call to
nmi_shootdown_cpus() during native_machine_emergency_restart().

Invoke the callback _before_ disabling virtualization, as the current
VMCS needs to be cleared before doing VMXOFF.  Note, this results in a
subtle change in ordering between disabling virtualization and stopping
Intel PT on the responding CPUs.  While VMX and Intel PT do interact,
VMXOFF and writes to MSR_IA32_RTIT_CTL do not induce faults between one
another, which is all that matters when panicking.

Harden nmi_shootdown_cpus() against multiple invocations to try and
capture any such kernel bugs via a WARN instead of hanging the system
during a crash/dump, e.g. prior to the recent hardening of
register_nmi_handler(), re-registering the NMI handler would trigger a
double list_add() and hang the system if CONFIG_BUG_ON_DATA_CORRUPTION=y.

 list_add double add: new=ffffffff82220800, prev=ffffffff8221cfe8, next=ffffffff82220800.
 WARNING: CPU: 2 PID: 1319 at lib/list_debug.c:29 __list_add_valid+0x67/0x70
 Call Trace:
  __register_nmi_handler+0xcf/0x130
  nmi_shootdown_cpus+0x39/0x90
  native_machine_emergency_restart+0x1c9/0x1d0
  panic+0x237/0x29b

Extract the disabling logic to a common helper to deduplicate code, and
to prepare for doing the shootdown in the emergency reboot path if SVM
is supported.

Note, prior to commit ed72736183 ("x86/reboot: Force all cpus to exit
VMX root if VMX is supported"), nmi_shootdown_cpus() was subtly protected
against a second invocation by a cpu_vmx_enabled() check as the kdump
handler would disable VMX if it ran first.

Fixes: ed72736183 ("x86/reboot: Force all cpus to exit VMX root if VMX is supported")
Cc: stable@vger.kernel.org
Reported-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/all/20220427224924.592546-2-gpiccoli@igalia.com
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20221130233650.1404148-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:34 +01:00
Sean Christopherson
28b136dbf1 x86/virt: Force GIF=1 prior to disabling SVM (for reboot flows)
commit 6a3236580b upstream.

Set GIF=1 prior to disabling SVM to ensure that INIT is recognized if the
kernel is disabling SVM in an emergency, e.g. if the kernel is about to
jump into a crash kernel or may reboot without doing a full CPU RESET.
If GIF is left cleared, the new kernel (or firmware) will be unabled to
awaken APs.  Eat faults on STGI (due to EFER.SVME=0) as it's possible
that SVM could be disabled via NMI shootdown between reading EFER.SVME
and executing STGI.

Link: https://lore.kernel.org/all/cbcb6f35-e5d7-c1c9-4db9-fe5cc4de579a@amd.com
Cc: stable@vger.kernel.org
Cc: Andrew Cooper <Andrew.Cooper3@citrix.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20221130233650.1404148-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:34 +01:00
Randy Dunlap
59dc47c151 KVM: SVM: hyper-v: placate modpost section mismatch error
commit 45dd9bc75d upstream.

modpost reports section mismatch errors/warnings:
WARNING: modpost: vmlinux.o: section mismatch in reference: svm_hv_hardware_setup (section: .text) -> (unknown) (section: .init.data)
WARNING: modpost: vmlinux.o: section mismatch in reference: svm_hv_hardware_setup (section: .text) -> (unknown) (section: .init.data)
WARNING: modpost: vmlinux.o: section mismatch in reference: svm_hv_hardware_setup (section: .text) -> (unknown) (section: .init.data)

This "(unknown) (section: .init.data)" all refer to svm_x86_ops.

Tag svm_hv_hardware_setup() with __init to fix a modpost warning as the
non-stub implementation accesses __initdata (svm_x86_ops), i.e. would
generate a use-after-free if svm_hv_hardware_setup() were actually invoked
post-init.  The helper is only called from svm_hardware_setup(), which is
also __init, i.e. lack of __init is benign other than the modpost warning.

Fixes: 1e0c7d4075 ("KVM: SVM: hyper-v: Remote TLB flush for SVM")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Vineeth Pillai <viremana@linux.microsoft.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Reviewed-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20230222073315.9081-1-rdunlap@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:34 +01:00
Peter Gonda
57e604e2e9 KVM: SVM: Fix potential overflow in SEV's send|receive_update_data()
commit f94f053aa3 upstream.

KVM_SEV_SEND_UPDATE_DATA and KVM_SEV_RECEIVE_UPDATE_DATA have an integer
overflow issue. Params.guest_len and offset are both 32 bits wide, with a
large params.guest_len the check to confirm a page boundary is not
crossed can falsely pass:

    /* Check if we are crossing the page boundary *
    offset = params.guest_uaddr & (PAGE_SIZE - 1);
    if ((params.guest_len + offset > PAGE_SIZE))

Add an additional check to confirm that params.guest_len itself is not
greater than PAGE_SIZE.

Note, this isn't a security concern as overflow can happen if and only if
params.guest_len is greater than 0xfffff000, and the FW spec says these
commands fail with lengths greater than 16KB, i.e. the PSP will detect
KVM's goof.

Fixes: 15fb7de1a7 ("KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command")
Fixes: d3d1af85e2 ("KVM: SVM: Add KVM_SEND_UPDATE_DATA command")
Reported-by: Andy Nguyen <theflow@google.com>
Suggested-by: Thomas Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Peter Gonda <pgonda@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20230207171354.4012821-1-pgonda@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:34 +01:00
Sean Christopherson
bbbd67a327 KVM: x86: Inject #GP on x2APIC WRMSR that sets reserved bits 63:32
commit ab52be1b31 upstream.

Reject attempts to set bits 63:32 for 32-bit x2APIC registers, i.e. all
x2APIC registers except ICR.  Per Intel's SDM:

  Non-zero writes (by WRMSR instruction) to reserved bits to these
  registers will raise a general protection fault exception

Opportunistically fix a typo in a nearby comment.

Reported-by: Marc Orr <marcorr@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20230107011025.565472-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:34 +01:00
Sean Christopherson
4e01634d74 KVM: x86: Inject #GP if WRMSR sets reserved bits in APIC Self-IPI
commit ba5838abb0 upstream.

Inject a #GP if the guest attempts to set reserved bits in the x2APIC-only
Self-IPI register.  Bits 7:0 hold the vector, all other bits are reserved.

Reported-by: Marc Orr <marcorr@google.com>
Cc: Ben Gardon <bgardon@google.com>
Cc: Venkatesh Srinivas <venkateshs@chromium.org>
Cc: stable@vger.kernel.org
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20230107011025.565472-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:34 +01:00
Sean Christopherson
e943f98967 KVM: SVM: Don't put/load AVIC when setting virtual APIC mode
commit e0bead97e7 upstream.

Move the VMCB updates from avic_refresh_apicv_exec_ctrl() into
avic_set_virtual_apic_mode() and invert the dependency being said
functions to avoid calling avic_vcpu_{load,put}() and
avic_set_pi_irte_mode() when "only" setting the virtual APIC mode.

avic_set_virtual_apic_mode() is invoked from common x86 with preemption
enabled, which makes avic_vcpu_{load,put}() unhappy.  Luckily, calling
those and updating IRTE stuff is unnecessary as the only reason
avic_set_virtual_apic_mode() is called is to handle transitions between
xAPIC and x2APIC that don't also toggle APICv activation.  And if
activation doesn't change, there's no need to fiddle with the physical
APIC ID table or update IRTE.

The "full" refresh is guaranteed to be called if activation changes in
this case as the only call to the "set" path is:

	kvm_vcpu_update_apicv(vcpu);
	static_call_cond(kvm_x86_set_virtual_apic_mode)(vcpu);

and kvm_vcpu_update_apicv() invokes the refresh if activation changes:

	if (apic->apicv_active == activate)
		goto out;

	apic->apicv_active = activate;
	kvm_apic_update_apicv(vcpu);
	static_call(kvm_x86_refresh_apicv_exec_ctrl)(vcpu);

Rename the helper to reflect that it is also called during "refresh".

  WARNING: CPU: 183 PID: 49186 at arch/x86/kvm/svm/avic.c:1081 avic_vcpu_put+0xde/0xf0 [kvm_amd]
  CPU: 183 PID: 49186 Comm: stable Tainted: G           O       6.0.0-smp--fcddbca45f0a-sink #34
  Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 10.48.0 01/27/2022
  RIP: 0010:avic_vcpu_put+0xde/0xf0 [kvm_amd]
   avic_refresh_apicv_exec_ctrl+0x142/0x1c0 [kvm_amd]
   avic_set_virtual_apic_mode+0x5a/0x70 [kvm_amd]
   kvm_lapic_set_base+0x149/0x1a0 [kvm]
   kvm_set_apic_base+0x8f/0xd0 [kvm]
   kvm_set_msr_common+0xa3a/0xdc0 [kvm]
   svm_set_msr+0x364/0x6b0 [kvm_amd]
   __kvm_set_msr+0xb8/0x1c0 [kvm]
   kvm_emulate_wrmsr+0x58/0x1d0 [kvm]
   msr_interception+0x1c/0x30 [kvm_amd]
   svm_invoke_exit_handler+0x31/0x100 [kvm_amd]
   svm_handle_exit+0xfc/0x160 [kvm_amd]
   vcpu_enter_guest+0x21bb/0x23e0 [kvm]
   vcpu_run+0x92/0x450 [kvm]
   kvm_arch_vcpu_ioctl_run+0x43e/0x6e0 [kvm]
   kvm_vcpu_ioctl+0x559/0x620 [kvm]

Fixes: 05c4fe8c1b ("KVM: SVM: Refresh AVIC configuration when changing APIC mode")
Cc: stable@vger.kernel.org
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230106011306.85230-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:33 +01:00
Sean Christopherson
ac46aca8d1 KVM: SVM: Process ICR on AVIC IPI delivery failure due to invalid target
commit 5aede752a8 upstream.

Emulate ICR writes on AVIC IPI failures due to invalid targets using the
same logic as failures due to invalid types.  AVIC acceleration fails if
_any_ of the targets are invalid, and crucially VM-Exits before sending
IPIs to targets that _are_ valid.  In logical mode, the destination is a
bitmap, i.e. a single IPI can target multiple logical IDs.  Doing nothing
causes KVM to drop IPIs if at least one target is valid and at least one
target is invalid.

Fixes: 18f40c53e1 ("svm: Add VMEXIT handlers for AVIC")
Cc: stable@vger.kernel.org
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230106011306.85230-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:33 +01:00
Sean Christopherson
164e2971ad KVM: SVM: Flush the "current" TLB when activating AVIC
commit 0ccf3e7cb9 upstream.

Flush the TLB when activating AVIC as the CPU can insert into the TLB
while AVIC is "locally" disabled.  KVM doesn't treat "APIC hardware
disabled" as VM-wide AVIC inhibition, and so when a vCPU has its APIC
hardware disabled, AVIC is not guaranteed to be inhibited.  As a result,
KVM may create a valid NPT mapping for the APIC base, which the CPU can
cache as a non-AVIC translation.

Note, Intel handles this in vmx_set_virtual_apic_mode().

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20230106011306.85230-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:33 +01:00
Sean Christopherson
c60d913797 KVM: x86: Don't inhibit APICv/AVIC if xAPIC ID mismatch is due to 32-bit ID
commit f651a00895 upstream.

Truncate the vcpu_id, a.k.a. x2APIC ID, to an 8-bit value when comparing
it against the xAPIC ID to avoid false positives (sort of) on systems
with >255 CPUs, i.e. with IDs that don't fit into a u8.  The intent of
APIC_ID_MODIFIED is to inhibit APICv/AVIC when the xAPIC is changed from
it's original value,

The mismatch isn't technically a false positive, as architecturally the
xAPIC IDs do end up being aliased in this scenario, and neither APICv
nor AVIC correctly handles IPI virtualization when there is aliasing.
However, KVM already deliberately does not honor the aliasing behavior
that results when an x2APIC ID gets truncated to an xAPIC ID.  I.e. the
resulting APICv/AVIC behavior is aligned with KVM's existing behavior
when KVM's x2APIC hotplug hack is effectively enabled.

If/when KVM provides a way to disable the hotplug hack, APICv/AVIC can
piggyback whatever logic disables the optimized APIC map (which is what
provides the hotplug hack), i.e. so that KVM's optimized map and APIC
virtualization yield the same behavior.

For now, fix the immediate problem of APIC virtualization being disabled
for large VMs, which is a much more pressing issue than ensuring KVM
honors architectural behavior for APIC ID aliasing.

Fixes: 3743c2f025 ("KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC base")
Reported-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230106011306.85230-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10 09:29:33 +01:00