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commit 187b96db5ca79423618dfa29a05c438c34f9e1f0 upstream.
Normally, show_trace_log_lvl() scans the stack, looking for text
addresses to print. In parallel, it unwinds the stack with
unwind_next_frame(). If the stack address matches the pointer returned
by unwind_get_return_address_ptr() for the current frame, the text
address is printed normally without a question mark. Otherwise it's
considered a breadcrumb (potentially from a previous call path) and it's
printed with a question mark to indicate that the address is unreliable
and typically can be ignored.
Since the following commit:
f1d9a2abff66 ("x86/unwind/orc: Don't skip the first frame for inactive tasks")
... for inactive tasks, show_trace_log_lvl() prints *only* unreliable
addresses (prepended with '?').
That happens because, for the first frame of an inactive task,
unwind_get_return_address_ptr() returns the wrong return address
pointer: one word *below* the task stack pointer. show_trace_log_lvl()
starts scanning at the stack pointer itself, so it never finds the first
'reliable' address, causing only guesses to being printed.
The first frame of an inactive task isn't a normal stack frame. It's
actually just an instance of 'struct inactive_task_frame' which is left
behind by __switch_to_asm(). Now that this inactive frame is actually
exposed to callers, fix unwind_get_return_address_ptr() to interpret it
properly.
Fixes: f1d9a2abff66 ("x86/unwind/orc: Don't skip the first frame for inactive tasks")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200522135435.vbxs7umku5pyrdbk@treble
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 8659a0e0efdd975c73355dbc033f79ba3b31e82c ]
Several strange crashes have been eventually traced back to
STRICT_KERNEL_RWX and its interaction with code patching.
Various paths in our ftrace, kprobes and other patching code need to
be hardened against patching failures, otherwise we can end up running
with partially/incorrectly patched ftrace paths, kprobes or jump
labels, which can then cause strange crashes.
Although fixes for those are in development, they're not -rc material.
There also seem to be problems with the underlying strict RWX logic,
which needs further debugging.
So for now disable STRICT_KERNEL_RWX on 64-bit to prevent people from
enabling the option and tripping over the bugs.
Fixes: 1e0fc9d1eb2b ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200520133605.972649-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit c55d7b5e64265fdca45c85b639013e770bde2d0e ]
I have tested this with the Radix MMU and everything seems to work, and
the previous patch for Hash seems to fix everything too.
STRICT_KERNEL_RWX should still be disabled by default for now.
Please test STRICT_KERNEL_RWX + RELOCATABLE!
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191224064126.183670-2-ruscur@russell.cc
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 8101b5a1531f3390b3a69fa7934c70a8fd6566ad ]
Stephen reported the following build warning on a ARM multi_v7_defconfig
build with GCC 9.2.1:
kernel/futex.c: In function 'do_futex':
kernel/futex.c:1676:17: warning: 'oldval' may be used uninitialized in this function [-Wmaybe-uninitialized]
1676 | return oldval == cmparg;
| ~~~~~~~^~~~~~~~~
kernel/futex.c:1652:6: note: 'oldval' was declared here
1652 | int oldval, ret;
| ^~~~~~
introduced by commit a08971e9488d ("futex: arch_futex_atomic_op_inuser()
calling conventions change").
While that change should not make any difference it confuses GCC which
fails to work out that oldval is not referenced when the return value is
not zero.
GCC fails to properly analyze arch_futex_atomic_op_inuser(). It's not the
early return, the issue is with the assembly macros. GCC fails to detect
that those either set 'ret' to 0 and set oldval or set 'ret' to -EFAULT
which makes oldval uninteresting. The store to the callsite supplied oldval
pointer is conditional on ret == 0.
The straight forward way to solve this is to make the store unconditional.
Aside of addressing the build warning this makes sense anyway because it
removes the conditional from the fastpath. In the error case the stored
value is uninteresting and the extra store does not matter at all.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87pncao2ph.fsf@nanos.tec.linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit c84cb3735fd53c91101ccdb191f2e3331a9262cb ]
Leon reported that the printk_once() in __setup_APIC_LVTT() triggers a
lockdep splat due to a lock order violation between hrtimer_base::lock and
console_sem, when the 'once' condition is reset via
/sys/kernel/debug/clear_warn_once after boot.
The initial printk cannot trigger this because that happens during boot
when the local APIC timer is set up on the boot CPU.
Prevent it by moving the printk to a place which is guaranteed to be only
called once during boot.
Mark the deadline timer check related functions and data __init while at
it.
Reported-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87y2qhoshi.fsf@nanos.tec.linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit c749bb2d554825e007cbc43b791f54e124dadfce upstream.
The current max_pfn equals to zero. In this case, I found it caused users
cannot get some page information through /proc such as kpagecount in v5.6
kernel because of new sanity checks. The following message is displayed by
stress-ng test suite with the command "stress-ng --verbose --physpage 1 -t
1" on HiFive unleashed board.
# stress-ng --verbose --physpage 1 -t 1
stress-ng: debug: [109] 4 processors online, 4 processors configured
stress-ng: info: [109] dispatching hogs: 1 physpage
stress-ng: debug: [109] cache allocate: reducing cache level from L3 (too high) to L0
stress-ng: debug: [109] get_cpu_cache: invalid cache_level: 0
stress-ng: info: [109] cache allocate: using built-in defaults as no suitable cache found
stress-ng: debug: [109] cache allocate: default cache size: 2048K
stress-ng: debug: [109] starting stressors
stress-ng: debug: [109] 1 stressor spawned
stress-ng: debug: [110] stress-ng-physpage: started [110] (instance 0)
stress-ng: error: [110] stress-ng-physpage: cannot read page count for address 0x3fd34de000 in /proc/kpagecount, errno=0 (Success)
stress-ng: error: [110] stress-ng-physpage: cannot read page count for address 0x3fd32db078 in /proc/kpagecount, errno=0 (Success)
...
stress-ng: error: [110] stress-ng-physpage: cannot read page count for address 0x3fd32db078 in /proc/kpagecount, errno=0 (Success)
stress-ng: debug: [110] stress-ng-physpage: exited [110] (instance 0)
stress-ng: debug: [109] process [110] terminated
stress-ng: info: [109] successful run completed in 1.00s
#
After applying this patch, the kernel can pass the test.
# stress-ng --verbose --physpage 1 -t 1
stress-ng: debug: [104] 4 processors online, 4 processors configured stress-ng: info: [104] dispatching hogs: 1 physpage
stress-ng: info: [104] cache allocate: using defaults, can't determine cache details from sysfs
stress-ng: debug: [104] cache allocate: default cache size: 2048K
stress-ng: debug: [104] starting stressors
stress-ng: debug: [104] 1 stressor spawned
stress-ng: debug: [105] stress-ng-physpage: started [105] (instance 0) stress-ng: debug: [105] stress-ng-physpage: exited [105] (instance 0) stress-ng: debug: [104] process [105] terminated
stress-ng: info: [104] successful run completed in 1.01s
#
Cc: stable@vger.kernel.org
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Yash Shah <yash.shah@sifive.com>
Tested-by: Yash Shah <yash.shah@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
[Palmer: back-ported to 4.19]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit d80b64ff297e40c2b6f7d7abc1b3eba70d22a068 upstream.
When kmalloc memory for sd->sev_vmcbs failed, we forget to free the page
held by sd->save_area. Also get rid of the var r as '-ENOMEM' is actually
the only possible outcome here.
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c4e0e4ab4cf3ec2b3f0b628ead108d677644ebd9 upstream.
Bank_num is a one-based count of banks, not a zero-based index. It
overflows the allocated space only when strictly greater than
KVM_MAX_MCE_BANKS.
Fixes: a9e38c3e01ad ("KVM: x86: Catch potential overrun in MCE setup")
Signed-off-by: Jue Wang <juew@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Message-Id: <20200511225616.19557-1-jmattson@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e47cb97f153193d4b41ca8d48127da14513d54c7 upstream.
The Clock Pulse Generator (CPG) device node lacks the extal2 clock.
This may lead to a failure registering the "r" clock, or to a wrong
parent for the "usb24s" clock, depending on MD_CK2 pin configuration and
boot loader CPG_USBCKCR register configuration.
This went unnoticed, as this does not affect the single upstream board
configuration, which relies on the first clock input only.
Fixes: d9ffd583bf345e2e ("ARM: shmobile: r8a7740: add SoC clocks to DTS")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Link: https://lore.kernel.org/r/20200508095918.6061-1-geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f4d71c6ea9e58c07dd4d02d09c5dd9bb780ec4b1 upstream.
Missing the renesas,ipmmu-main property on ipmmu_vip[01] nodes.
Fixes: 55697cbb44e4 ("arm64: dts: renesas: r8a779{65,80,90}: Add IPMMU devices nodes)
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/1587108543-23786-1-git-send-email-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 0f739fdfe9e5ce668bd6d3210f310df282321837 upstream.
The R-Mobile APE6 Compare Match Timer 1 generates 8 interrupts, one for
each channel, but currently only 1 is described.
Fix this by adding the missing interrupts.
Fixes: f7b65230019b9dac ("ARM: shmobile: r8a73a4: Add CMT1 node")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200408090926.25201-1-geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 190c7f6fd43a776d4a6da1dac44408104649e9b7 upstream.
The device tree compiler complains that the dwc3 nodes have regs
properties but no matching unit addresses.
Add the unit addresses to the device node name. While at it, also rename
the nodes from "dwc3" to "usb", as guidelines require device nodes have
generic names.
Fixes: 7144224f2c2b ("arm64: dts: rockchip: support dwc3 USB for rk3399")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20200327030414.5903-7-wens@kernel.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 83b994129fb4c18a8460fd395864a28740e5e7fb upstream.
In some board device tree files, "rk805" was used for the RK805 PMIC's
node name. However the policy for device trees is that generic names
should be used.
Replace the "rk805" node name with the generic "pmic" name.
Fixes: 1e28037ec88e ("arm64: dts: rockchip: add rk805 node for rk3328-evb")
Fixes: 955bebde057e ("arm64: dts: rockchip: add rk3328-rock64 board")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20200327030414.5903-3-wens@kernel.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 71c95825289f585014fe9741b051d32a7a916680 upstream.
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: af085d9084b4 ("stacktrace/x86: add function for detecting reliable stack traces")
Fixes: d3a09104018c ("x86/unwinder/orc: Dont bail on stack overflow")
Fixes: 98d0c8ebf77e ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit a9a3ed1eff3601b63aea4fb462d8b3b92c7c1e7e upstream.
... 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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 0caf34350a25907515d929a9c77b9b206aac6d1e upstream.
The I2C2 pins are already used and the following errors are seen:
imx27-pinctrl 10015000.iomuxc: pin MX27_PAD_I2C2_SDA already requested by 10012000.i2c; cannot claim for 1001d000.i2c
imx27-pinctrl 10015000.iomuxc: pin-69 (1001d000.i2c) status -22
imx27-pinctrl 10015000.iomuxc: could not request pin 69 (MX27_PAD_I2C2_SDA) from group i2c2grp on device 10015000.iomuxc
imx-i2c 1001d000.i2c: Error applying setting, reverse things back
imx-i2c: probe of 1001d000.i2c failed with error -22
Fix it by adding the correct I2C1 IOMUX entries for the pinctrl_i2c1 group.
Cc: <stable@vger.kernel.org>
Fixes: 61664d0b432a ("ARM: dts: imx27 phyCARD-S pinctrl")
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Stefan Riedmueller <s.riedmueller@phytec.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 90d4d3f4ea45370d482fa609dbae4d2281b4074f upstream.
Even though commit cfb5d65f2595 ("ARM: dts: dra7: Add bus_dma_limit
for L3 bus") added bus_dma_limit for L3 bus, the PCIe controller
gets incorrect value of bus_dma_limit.
Fix it by adding empty dma-ranges property to axi@0 and axi@1
(parent device tree node of PCIe controller).
Cc: stable@kernel.org
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit d51c214541c5154dda3037289ee895ea3ded5ebd ]
The second argument is the end "pointer", not the length.
Fixes: d28f6df1305a ("arm64/kexec: Add core kexec support")
Cc: <stable@vger.kernel.org> # 4.8.x-
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 3c1918c8f54166598195d938564072664a8275b1 ]
When building with the LLVM linker this error occurrs:
LD arch/riscv/kernel/vdso/vdso-syms.o
ld.lld: error: no input files
This happens because the lld treats -R as an alias to -rpath, as opposed
to ld where -R means --just-symbols.
Use the long option name for compatibility between the two.
Link: https://github.com/ClangBuiltLinux/linux/issues/805
Reported-by: Dmitry Golovin <dima@golovin.in>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Ilie Halip <ilie.halip@gmail.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 81b67439d147677d844d492fcbd03712ea438f42 upstream.
The following execution path is possible:
fsnotify()
[ realign the stack and store previous SP in R10 ]
<IRQ>
[ only IRET regs saved ]
common_interrupt()
interrupt_entry()
<NMI>
[ full pt_regs saved ]
...
[ unwind stack ]
When the unwinder goes through the NMI and the IRQ on the stack, and
then sees fsnotify(), it doesn't have access to the value of R10,
because it only has the five IRET registers. So the unwind stops
prematurely.
However, because the interrupt_entry() code is careful not to clobber
R10 before saving the full regs, the unwinder should be able to read R10
from the previously saved full pt_regs associated with the NMI.
Handle this case properly. When encountering an IRET regs frame
immediately after a full pt_regs frame, use the pt_regs as a backup
which can be used to get the C register values.
Also, note that a call frame resets the 'prev_regs' value, because a
function is free to clobber the registers. For this fix to work, the
IRET and full regs frames must be adjacent, with no FUNC frames in
between. So replace the FUNC hint in interrupt_entry() with an
IRET_REGS hint.
Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Jones <dsj@fb.com>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lore.kernel.org/r/97a408167cc09f1cfa0de31a7b70dd88868d743f.1587808742.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit a0f81bf26888048100bf017fadf438a5bdffa8d8 upstream.
If the ORC entry type is unknown, nothing else can be done other than
reporting an error. Exit the function instead of breaking out of the
switch statement.
Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Jones <dsj@fb.com>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lore.kernel.org/r/a7fa668ca6eabbe81ab18b2424f15adbbfdc810a.1587808742.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 98d0c8ebf77e0ba7c54a9ae05ea588f0e9e3f46e upstream.
If the unwinder is called before the ORC data has been initialized,
orc_find() returns NULL, and it tries to fall back to using frame
pointers. This can cause some unexpected warnings during boot.
Move the 'orc_init' check from orc_find() to __unwind_init(), so that it
doesn't even try to unwind from an uninitialized state.
Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Jones <dsj@fb.com>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lore.kernel.org/r/069d1499ad606d85532eb32ce39b2441679667d5.1587808742.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f1d9a2abff66aa8156fbc1493abed468db63ea48 upstream.
When unwinding an inactive task, the ORC unwinder skips the first frame
by default. If both the 'regs' and 'first_frame' parameters of
unwind_start() are NULL, 'state->sp' and 'first_frame' are later
initialized to the same value for an inactive task. Given there is a
"less than or equal to" comparison used at the end of __unwind_start()
for skipping stack frames, the first frame is skipped.
Drop the equal part of the comparison and make the behavior equivalent
to the frame pointer unwinder.
Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Jones <dsj@fb.com>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lore.kernel.org/r/7f08db872ab59e807016910acdbe82f744de7065.1587808742.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f977df7b7ca45a4ac4b66d30a8931d0434c394b1 upstream.
The LEAQ instruction in rewind_stack_do_exit() moves the stack pointer
directly below the pt_regs at the top of the task stack before calling
do_exit(). Tell the unwinder to expect pt_regs.
Fixes: 8c1f75587a18 ("x86/entry/64: Add unwind hint annotations")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Jones <dsj@fb.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lore.kernel.org/r/68c33e17ae5963854916a46f522624f8e1d264f2.1587808742.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1fb143634a38095b641a3a21220774799772dc4c upstream.
In swapgs_restore_regs_and_return_to_usermode, after the stack is
switched to the trampoline stack, the existing UNWIND_HINT_REGS hint is
no longer valid, which can result in the following ORC unwinder warning:
WARNING: can't dereference registers at 000000003aeb0cdd for ip swapgs_restore_regs_and_return_to_usermode+0x93/0xa0
For full correctness, we could try to add complicated unwind hints so
the unwinder could continue to find the registers, but when when it's
this close to kernel exit, unwind hints aren't really needed anymore and
it's fine to just use an empty hint which tells the unwinder to stop.
For consistency, also move the UNWIND_HINT_EMPTY in
entry_SYSCALL_64_after_hwframe to a similar location.
Fixes: 3e3b9293d392 ("x86/entry/64: Return to userspace from the trampoline stack")
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Reported-by: Dave Jones <dsj@fb.com>
Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reported-by: Joe Mario <jmario@redhat.com>
Reported-by: Jann Horn <jannh@google.com>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/60ea8f562987ed2d9ace2977502fe481c0d7c9a0.1587808742.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 06a9750edcffa808494d56da939085c35904e618 upstream.
The PUSH_AND_CLEAR_REGS macro zeroes each register immediately after
pushing it. If an NMI or exception hits after a register is cleared,
but before the UNWIND_HINT_REGS annotation, the ORC unwinder will
wrongly think the previous value of the register was zero. This can
confuse the unwinding process and cause it to exit early.
Because ORC is simpler than DWARF, there are a limited number of unwind
annotation states, so it's not possible to add an individual unwind hint
after each push/clear combination. Instead, the register clearing
instructions need to be consolidated and moved to after the
UNWIND_HINT_REGS annotation.
Fixes: 3f01daecd545 ("x86/entry/64: Introduce the PUSH_AND_CLEAN_REGS macro")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Jones <dsj@fb.com>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lore.kernel.org/r/68fd3d0bc92ae2d62ff7879d15d3684217d51f08.1587808742.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Based on upstream commit f3689e3f17f064fd4cd5f0cb01ae2395c94f39d9.
Save RCX, RDX and RSI to fake outputs to coerce the compiler into
treating them as clobbered. RCX in particular is likely to be reused by
the compiler to dereference the 'struct vcpu_vmx' pointer, which will
result in a null pointer dereference now that RCX is zeroed by the asm
blob.
Tag the asm() blob as volatile to prevent GCC from dropping the blob,
which is possible now that the blob has output values, all of which are
unused.
Upstream commit f3689e3f17f06 ("KVM: VMX: Save RSI to an unused output
in the vCPU-run asm blob") is not a direct equivalent of this patch. As
its shortlog states, it only tagged RSI as clobbered, whereas here RCX
and RDX are also clobbered.
In upstream at the time of the offending commit (b4be98039a92 in 4.19,
0e0ab73c9a024 upstream), the inline asm blob had previously been moved
to a dedicated helper, __vmx_vcpu_run(). For unrelated reasons,
__vmx_vcpu_run() was put into its own optimization unit, which for all
intents and purposes made it impossible to consume clobbered registers
because RCX, RDX and RSI are volatile and __vmx_vcpu_run() couldn't
itself be inlined. In other words, the bug existed but couldn't be hit.
Similarly, the lack of "volatile" was also a bug in upstream that was
hidden by an unrelated change that exists in upstream but not in 4.19.
In this case, the asm blob also uses ASM_CALL_CONSTRAINT (marks RSP as
being an input/output constraint) in upstream to play nice with objtool
due the blob making a CALL. In 4.19, there is no CALL and thus no
ASM_CALL_CONSTRAINT.
Furthermore, both of the lurking bugs were blasted away in upstream by
commits 5e0781df1899 ("KVM: VMX: Move vCPU-run code to a proper assembly
routine") and fc2ba5a27a1a ("KVM: VMX: Call vCPU-run asm sub-routine
from C and remove clobbering"), i.e. these bugs will never be directly
fixed in upstream.
Reported-by: Tobias Urdin <tobias.urdin@binero.com>
Fixes: b4be98039a92 ("KVM: VMX: Zero out *all* general purpose registers after VM-Exit")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 051a2d3e59e51ae49fd56aef34e472832897ce46 upstream.
Use '%% " _ASM_CX"' instead of '%0' to dereference RCX, i.e. the
'struct vcpu_vmx' pointer, in the VM-Enter asm blobs of vmx_vcpu_run()
and nested_vmx_check_vmentry_hw(). Using the symbolic name means that
adding/removing an output parameter(s) requires "rewriting" almost all
of the asm blob, which makes it nearly impossible to understand what's
being changed in even the most minor patches.
Opportunistically improve the code comments.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 027d0c7101f50cf03aeea9eebf484afd4920c8d3 upstream.
The static analyzer in GCC 10 spotted that in huge_pte_alloc() we may
pass a NULL pmdp into pte_alloc_map() when pmd_alloc() returns NULL:
| CC arch/arm64/mm/pageattr.o
| CC arch/arm64/mm/hugetlbpage.o
| from arch/arm64/mm/hugetlbpage.c:10:
| arch/arm64/mm/hugetlbpage.c: In function ‘huge_pte_alloc’:
| ./arch/arm64/include/asm/pgtable-types.h:28:24: warning: dereference of NULL ‘pmdp’ [CWE-690] [-Wanalyzer-null-dereference]
| ./arch/arm64/include/asm/pgtable.h:436:26: note: in expansion of macro ‘pmd_val’
| arch/arm64/mm/hugetlbpage.c:242:10: note: in expansion of macro ‘pte_alloc_map’
| |arch/arm64/mm/hugetlbpage.c:232:10:
| |./arch/arm64/include/asm/pgtable-types.h:28:24:
| ./arch/arm64/include/asm/pgtable.h:436:26: note: in expansion of macro ‘pmd_val’
| arch/arm64/mm/hugetlbpage.c:242:10: note: in expansion of macro ‘pte_alloc_map’
This can only occur when the kernel cannot allocate a page, and so is
unlikely to happen in practice before other systems start failing.
We can avoid this by bailing out if pmd_alloc() fails, as we do earlier
in the function if pud_alloc() fails.
Fixes: 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Kyrill Tkachov <kyrylo.tkachov@arm.com>
Cc: <stable@vger.kernel.org> # 4.5.x-
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 0225fd5e0a6a32af7af0aefac45c8ebf19dc5183 upstream.
In the unlikely event that a 32bit vcpu traps into the hypervisor
on an instruction that is located right at the end of the 32bit
range, the emulation of that instruction is going to increment
PC past the 32bit range. This isn't great, as userspace can then
observe this value and get a bit confused.
Conversly, userspace can do things like (in the context of a 64bit
guest that is capable of 32bit EL0) setting PSTATE to AArch64-EL0,
set PC to a 64bit value, change PSTATE to AArch32-USR, and observe
that PC hasn't been truncated. More confusion.
Fix both by:
- truncating PC increments for 32bit guests
- sanitizing all 32bit regs every time a core reg is changed by
userspace, and that PSTATE indicates a 32bit mode.
Cc: stable@vger.kernel.org
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7312b70699252074d753c5005fc67266c547bbe3 upstream.
Similar to commit 38e45d81d14e ("sparc64: implement ioremap_uc") define
ioremap_uc for hexagon to avoid errors from
-Wimplicit-function-definition.
Link: http://lkml.kernel.org/r/20191209222956.239798-2-ndesaulniers@google.com
Link: https://github.com/ClangBuiltLinux/linux/issues/797
Fixes: e537654b7039 ("lib: devres: add a helper function for ioremap_uc")
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Brian Cain <bcain@codeaurora.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Tuowen Zhao <ztuowen@gmail.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexios Zavras <alexios.zavras@intel.com>
Cc: Allison Randal <allison@lohutok.net>
Cc: Will Deacon <will@kernel.org>
Cc: Richard Fontana <rfontana@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ac32292c8552f7e8517be184e65dd09786e991f9 upstream.
Use ioremap as the main implemented function, and defined
ioremap_nocache to it as a deprecated alias.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 8ebf6da9db1b2a20bb86cc1bee2552e894d03308 ]
Switching tracers include instruction patching. To prevent that a
instruction is patched while it's read the instruction patching is done
in stop_machine 'context'. This also means that any function called
during stop_machine must not be traced. Thus add 'notrace' to all
functions called within stop_machine.
Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls")
Fixes: 38f2c691a4b3 ("s390: improve wait logic of stop_machine")
Fixes: 4ecf0a43e729 ("processor: get rid of cpu_relax_yield")
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit dead1c845dbe97e0061dae2017eaf3bd8f8f06ee upstream.
The pseries platform uses the PCI_PROBE_DEVTREE method of PCI probing
which reads "assigned-addresses" of every PCI device and initializes
the device resources. However if the property is missing or zero sized,
then there is no fallback of any kind and the PCI resources remain
undiscovered, i.e. pdev->resource[] array remains empty.
This adds a fallback which parses the "reg" property in pretty much same
way except it marks resources as "unset" which later make Linux assign
those resources proper addresses.
This has an effect when:
1. a hypervisor failed to assign any resource for a device;
2. /chosen/linux,pci-probe-only=0 is in the DT so the system may try
assigning a resource.
Neither is likely to happen under PowerVM.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 50fe7ebb6475711c15b3397467e6424e20026d94 upstream.
The current JIT clobbers the destination register for BPF_JSET BPF_X
and BPF_K by using "and" and "or" instructions. This is fine when the
destination register is a temporary loaded from a register stored on
the stack but not otherwise.
This patch fixes the problem (for both BPF_K and BPF_X) by always loading
the destination register into temporaries since BPF_JSET should not
modify the destination register.
This bug may not be currently triggerable as BPF_REG_AX is the only
register not stored on the stack and the verifier uses it in a limited
way.
Fixes: 03f5781be2c7b ("bpf, x86_32: add eBPF JIT compiler for ia32")
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Wang YanQing <udknight@gmail.com>
Link: https://lore.kernel.org/bpf/20200422173630.8351-2-luke.r.nels@gmail.com
Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit c9a4ef66450145a356a626c833d3d7b1668b3ded ]
In assembly, many instances of __emit_inst(x) expand to a directive. In
a few places __emit_inst(x) is used as an assembler macro argument. For
example, in arch/arm64/kvm/hyp/entry.S
ALTERNATIVE(nop, SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN)
expands to the following by the C preprocessor:
alternative_insn nop, .inst (0xd500401f | ((0) << 16 | (4) << 5) | ((!!1) << 8)), 4, 1
Both comma and space are separators, with an exception that content
inside a pair of parentheses/quotes is not split, so the clang
integrated assembler splits the arguments to:
nop, .inst, (0xd500401f | ((0) << 16 | (4) << 5) | ((!!1) << 8)), 4, 1
GNU as preprocesses the input with do_scrub_chars(). Its arm64 backend
(along with many other non-x86 backends) sees:
alternative_insn nop,.inst(0xd500401f|((0)<<16|(4)<<5)|((!!1)<<8)),4,1
# .inst(...) is parsed as one argument
while its x86 backend sees:
alternative_insn nop,.inst (0xd500401f|((0)<<16|(4)<<5)|((!!1)<<8)),4,1
# The extra space before '(' makes the whole .inst (...) parsed as two arguments
The non-x86 backend's behavior is considered unintentional
(https://sourceware.org/bugzilla/show_bug.cgi?id=25750).
So drop the space separator inside `.inst (...)` to make the clang
integrated assembler work.
Suggested-by: Ilie Halip <ilie.halip@gmail.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/939
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 97d9f1c43bedd400301d6f1eff54d46e8c636e47 ]
A few kernel features depend on ms_hyperv.misc_features, but unlike its
siblings ->features and ->hints, the value was never reported during boot.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Link: https://lore.kernel.org/r/20200407172739.31371-1-olaf@aepfle.de
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit aee194b14dd2b2bde6252b3acf57d36dccfc743a ]
This patch fixes an encoding bug in emit_stx for BPF_B when the source
register is BPF_REG_FP.
The current implementation for BPF_STX BPF_B in emit_stx saves one REX
byte when the operands can be encoded using Mod-R/M alone. The lower 8
bits of registers %rax, %rbx, %rcx, and %rdx can be accessed without using
a REX prefix via %al, %bl, %cl, and %dl, respectively. Other registers,
(e.g., %rsi, %rdi, %rbp, %rsp) require a REX prefix to use their 8-bit
equivalents (%sil, %dil, %bpl, %spl).
The current code checks if the source for BPF_STX BPF_B is BPF_REG_1
or BPF_REG_2 (which map to %rdi and %rsi), in which case it emits the
required REX prefix. However, it misses the case when the source is
BPF_REG_FP (mapped to %rbp).
The result is that BPF_STX BPF_B with BPF_REG_FP as the source operand
will read from register %ch instead of the correct %bpl. This patch fixes
the problem by fixing and refactoring the check on which registers need
the extra REX byte. Since no BPF registers map to %rsp, there is no need
to handle %spl.
Fixes: 622582786c9e0 ("net: filter: x86: internal BPF JIT")
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200418232655.23870-1-luke.r.nels@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 5fa9a98fb10380e48a398998cd36a85e4ef711d6 upstream.
The current JIT uses the following sequence to zero-extend into the
upper 32 bits of the destination register for BPF_LDX BPF_{B,H,W},
when the destination register is not on the stack:
EMIT3(0xC7, add_1reg(0xC0, dst_hi), 0);
The problem is that C7 /0 encodes a MOV instruction that requires a 4-byte
immediate; the current code emits only 1 byte of the immediate. This
means that the first 3 bytes of the next instruction will be treated as
the rest of the immediate, breaking the stream of instructions.
This patch fixes the problem by instead emitting "xor dst_hi,dst_hi"
to clear the upper 32 bits. This fixes the problem and is more efficient
than using MOV to load a zero immediate.
This bug may not be currently triggerable as BPF_REG_AX is the only
register not stored on the stack and the verifier uses it in a limited
way, and the verifier implements a zero-extension optimization. But the
JIT should avoid emitting incorrect encodings regardless.
Fixes: 03f5781be2c7b ("bpf, x86_32: add eBPF JIT compiler for ia32")
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Acked-by: Wang YanQing <udknight@gmail.com>
Link: https://lore.kernel.org/bpf/20200422173630.8351-1-luke.r.nels@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 90444b958461a5f8fc299ece0fe17eab15cba1e1 upstream.
Since its inception the module was meant to be disabled by default, but
the original commit failed to add the relevant property.
Fixes: 4aba4cf82054 ("ARM: dts: bcm2835: Add the DSI module nodes and clocks")
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 316ec154810960052d4586b634156c54d0778f74 upstream.
A page table upgrade in a kernel section that uses secondary address
mode will mess up the kernel instructions as follows:
Consider the following scenario: two threads are sharing memory.
On CPU1 thread 1 does e.g. strnlen_user(). That gets to
old_fs = enable_sacf_uaccess();
len = strnlen_user_srst(src, size);
and
" la %2,0(%1)\n"
" la %3,0(%0,%1)\n"
" slgr %0,%0\n"
" sacf 256\n"
"0: srst %3,%2\n"
in strnlen_user_srst(). At that point we are in secondary space mode,
control register 1 points to kernel page table and instruction fetching
happens via c1, rather than usual c13. Interrupts are not disabled, for
obvious reasons.
On CPU2 thread 2 does MAP_FIXED mmap(), forcing the upgrade of page table
from 3-level to e.g. 4-level one. We'd allocated new top-level table,
set it up and now we hit this:
notify = 1;
spin_unlock_bh(&mm->page_table_lock);
}
if (notify)
on_each_cpu(__crst_table_upgrade, mm, 0);
OK, we need to actually change over to use of new page table and we
need that to happen in all threads that are currently running. Which
happens to include the thread 1. IPI is delivered and we have
static void __crst_table_upgrade(void *arg)
{
struct mm_struct *mm = arg;
if (current->active_mm == mm)
set_user_asce(mm);
__tlb_flush_local();
}
run on CPU1. That does
static inline void set_user_asce(struct mm_struct *mm)
{
S390_lowcore.user_asce = mm->context.asce;
OK, user page table address updated...
__ctl_load(S390_lowcore.user_asce, 1, 1);
... and control register 1 set to it.
clear_cpu_flag(CIF_ASCE_PRIMARY);
}
IPI is run in home space mode, so it's fine - insns are fetched
using c13, which always points to kernel page table. But as soon
as we return from the interrupt, previous PSW is restored, putting
CPU1 back into secondary space mode, at which point we no longer
get the kernel instructions from the kernel mapping.
The fix is to only fixup the control registers that are currently in use
for user processes during the page table update. We must also disable
interrupts in enable_sacf_uaccess to synchronize the cr and
thread.mm_segment updates against the on_each-cpu.
Fixes: 0aaba41b58bc ("s390: remove all code using the access register mode")
Cc: stable@vger.kernel.org # 4.15+
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
References: CVE-2020-11884
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 94c0b013c98583614e1ad911e8795ca36da34a85 upstream.
If {i,d}-cache-block-size is set and {i,d}-cache-line-size is not, use
the block-size value for both. Per the devicetree spec cache-line-size
is only needed if it differs from the block size.
Originally the code would fallback from block size to line size. An
error message was printed if both properties were missing.
Later the code was refactored to use clearer names and logic but it
inadvertently made line size a required property, meaning on systems
without a line size property we fall back to the default from the
cputable.
On powernv (OPAL) platforms, since the introduction of device tree CPU
features (5a61ef74f269 ("powerpc/64s: Support new device tree binding
for discovering CPU features")), that has led to the wrong value being
used, as the fallback value is incorrect for Power8/Power9 CPUs.
The incorrect values flow through to the VDSO and also to the sysconf
values, SC_LEVEL1_ICACHE_LINESIZE etc.
Fixes: bd067f83b084 ("powerpc/64: Fix naming of cache block vs. cache line")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reported-by: Qian Cai <cai@lca.pw>
[mpe: Add even more detail to change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200416221908.7886-1-chris.packham@alliedtelesis.co.nz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f1baca8896ae18e12c45552a4c4ae2086aa7e02c upstream.
512a928affd5 ("ARM: imx: build v7_cpu_resume() unconditionally")
introduced an unintended linker error for i.MX6 configurations that have
ARM_CPU_SUSPEND=n which can happen if neither CONFIG_PM, CONFIG_CPU_IDLE,
nor ARM_PSCI_FW are selected.
Fix this by having v7_cpu_resume() compiled only when cpu_resume() it
calls is available as well.
The C declaration for the function remains unguarded to avoid future code
inadvertently using a stub and introducing a regression to the bug the
original commit fixed.
Cc: <stable@vger.kernel.org>
Fixes: 512a928affd5 ("ARM: imx: build v7_cpu_resume() unconditionally")
Reported-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Tested-by: Roland Hieber <rhi@pengutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit fb56baae5ea509e63c2a068d66a4d8ea91969fca upstream.
There is no reason to limit the use of do_machine_check
to 64bit targets. MCE handling works for both target familes.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: stable@vger.kernel.org
Fixes: a0861c02a981 ("KVM: Add VT-x machine check support")
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Message-Id: <20200414071414.45636-1-ubizjak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 97daa028f3f621adff2c4f7b15fe0874e5b5bd6c upstream.
Return the index of the last valid slot from gfn_to_memslot_approx() if
its binary search loop yielded an out-of-bounds index. The index can
be out-of-bounds if the specified gfn is less than the base of the
lowest memslot (which is also the last valid memslot).
Note, the sole caller, kvm_s390_get_cmma(), ensures used_slots is
non-zero.
Fixes: afdad61615cc3 ("KVM: s390: Fix storage attributes migration with memory slots")
Cc: stable@vger.kernel.org # 4.19.x: 0774a964ef56: KVM: Fix out of range accesses to memslots
Cc: stable@vger.kernel.org # 4.19.x
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200408064059.8957-3-sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit a6bd811f1209fe1c64c9f6fd578101d6436c6b6e upstream.
Now that we are mapping kvm_steal_time from the guest directly we
don't need keep a copy of it in kvm_vcpu_arch.st. The same is true
for the stime field.
This is part of CVE-2019-3016.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit b043138246a41064527cf019a3d51d9f015e9796 upstream.
There is a potential race in record_steal_time() between setting
host-local vcpu->arch.st.steal.preempted to zero (i.e. clearing
KVM_VCPU_PREEMPTED) and propagating this value to the guest with
kvm_write_guest_cached(). Between those two events the guest may
still see KVM_VCPU_PREEMPTED in its copy of kvm_steal_time, set
KVM_VCPU_FLUSH_TLB and assume that hypervisor will do the right
thing. Which it won't.
Instad of copying, we should map kvm_steal_time and that will
guarantee atomicity of accesses to @preempted.
This is part of CVE-2019-3016.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 4.19: No tracepoint in record_steal_time().]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 917248144db5d7320655dbb41d3af0b8a0f3d589 upstream.
__kvm_map_gfn()'s call to gfn_to_pfn_memslot() is
* relatively expensive
* in certain cases (such as when done from atomic context) cannot be called
Stashing gfn-to-pfn mapping should help with both cases.
This is part of CVE-2019-3016.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 3b013a2972d5bc344d6eaa8f24fdfe268211e45f upstream.
If L1 does not set VM_ENTRY_LOAD_BNDCFGS, then L1's BNDCFGS value must
be propagated to vmcs02 since KVM always runs with VM_ENTRY_LOAD_BNDCFGS
when MPX is supported. Because the value effectively comes from vmcs01,
vmcs02 must be updated even if vmcs12 is clean.
Fixes: 62cf9bd8118c4 ("KVM: nVMX: Fix emulation of VM_ENTRY_LOAD_BNDCFGS")
Cc: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 4.19: adjust filename, context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 0e0ab73c9a0243736bcd779b30b717e23ba9a56d upstream.
...except RSP, which is restored by hardware as part of VM-Exit.
Paolo theorized that restoring registers from the stack after a VM-Exit
in lieu of zeroing them could lead to speculative execution with the
guest's values, e.g. if the stack accesses miss the L1 cache[1].
Zeroing XORs are dirt cheap, so just be ultra-paranoid.
Note that the scratch register (currently RCX) used to save/restore the
guest state is also zeroed as its host-defined value is loaded via the
stack, just with a MOV instead of a POP.
[1] https://patchwork.kernel.org/patch/10771539/#22441255
Fixes: 0cb5b30698fd ("kvm: vmx: Scrub hardware GPRs at VM-exit")
Cc: Jim Mattson <jmattson@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 4.19: adjust filename, context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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Josh Poimboeuf
Michael Ellerman
Russell Currey
Thomas Gleixner
Vincent Chen
Miaohe Lin
Jim Mattson
Geert Uytterhoeven
Yoshihiro Shimoda
Chen-Yu Tsai
Borislav Petkov
Fabio Estevam
Kishon Vijay Abraham I
Christoph Hellwig
Ilie Halip
Miroslav Benes
Jann Horn
Sean Christopherson
Mark Rutland
Marc Zyngier
Nick Desaulniers
Philipp Rudo
Alexey Kardashevskiy
Luke Nelson
Fangrui Song
Olaf Hering
Nicolas Saenz Julienne
Christian Borntraeger
Chris Packham
Ahmad Fatoum
Uros Bizjak
Boris Ostrovsky