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This reverts commit 66fe51cb35d91d75a67ec8a38caf03da95e8c191 which is
commit 53c613fe6349994f023245519265999eed75957f upstream.
It's not ready for the stable trees as there are major slowdowns
involved with this patch.
Reported-by: Jiri Kosina <jkosina@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "WoodhouseDavid" <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: "SchauflerCasey" <casey.schaufler@intel.com>
Cc: Rainer Fiebig <jrf@mailbox.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit a3c0f84765bb429ba0fd23de1c57b5e1591c9389 upstream.
Spectre variant 1 attacks are about this sequence of pseudo-code:
index = load(user-manipulated pointer);
access(base + index * stride);
In order for the cache side-channel to work, the access() must me made
to memory which userspace can detect whether cache lines have been
loaded. On 32-bit ARM, this must be either user accessible memory, or
a kernel mapping of that same user accessible memory.
The problem occurs when the load() speculatively loads privileged data,
and the subsequent access() is made to user accessible memory.
Any load() which makes use of a user-maniplated pointer is a potential
problem if the data it has loaded is used in a subsequent access. This
also applies for the access() if the data loaded by that access is used
by a subsequent access.
Harden the get_user() accessors against Spectre attacks by forcing out
of bounds addresses to a NULL pointer. This prevents get_user() being
used as the load() step above. As a side effect, put_user() will also
be affected even though it isn't implicated.
Also harden copy_from_user() by redoing the bounds check within the
arm_copy_from_user() code, and NULLing the pointer if out of bounds.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit b1cd0a14806321721aae45f5446ed83a3647c914 upstream.
Fixing __get_user() for spectre variant 1 is not sane: we would have to
add address space bounds checking in order to validate that the location
should be accessed, and then zero the address if found to be invalid.
Since __get_user() is supposed to avoid the bounds check, and this is
exactly what get_user() does, there's no point having two different
implementations that are doing the same thing. So, when the Spectre
workarounds are required, make __get_user() an alias of get_user().
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit d09fbb327d670737ab40fd8bbb0765ae06b8b739 upstream.
Borrow the x86 implementation of __inttype() to use in get_user() to
select an integer type suitable to temporarily hold the result value.
This is necessary to avoid propagating the volatile nature of the
result argument, which can cause the following warning:
lib/iov_iter.c:413:5: warning: optimization may eliminate reads and/or writes to register variables [-Wvolatile-register-var]
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 8c8484a1c18e3231648f5ba7cc5ffb7fd70b3ca4 upstream.
__get_user_error() is used as a fast accessor to make copying structure
members as efficient as possible. However, with software PAN and the
recent Spectre variant 1, the efficiency is reduced as these are no
longer fast accessors.
In the case of software PAN, it has to switch the domain register around
each access, and with Spectre variant 1, it would have to repeat the
access_ok() check for each access.
Rather than using __get_user_error() to copy each semops element member,
copy each semops element in full using __copy_from_user().
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 42019fc50dfadb219f9e6ddf4c354f3837057d80 upstream.
__get_user_error() is used as a fast accessor to make copying structure
members in the signal handling path as efficient as possible. However,
with software PAN and the recent Spectre variant 1, the efficiency is
reduced as these are no longer fast accessors.
In the case of software PAN, it has to switch the domain register around
each access, and with Spectre variant 1, it would have to repeat the
access_ok() check for each access.
Use __copy_from_user() rather than __get_user_err() for individual
members when restoring VFP state.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit c32cd419d6650e42b9cdebb83c672ec945e6bd7e upstream.
__get_user_error() is used as a fast accessor to make copying structure
members in the signal handling path as efficient as possible. However,
with software PAN and the recent Spectre variant 1, the efficiency is
reduced as these are no longer fast accessors.
In the case of software PAN, it has to switch the domain register around
each access, and with Spectre variant 1, it would have to repeat the
access_ok() check for each access.
It becomes much more efficient to use __copy_from_user() instead, so
let's use this for the ARM integer registers.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 10573ae547c85b2c61417ff1a106cffbfceada35 upstream.
Prevent speculation at the syscall table decoding by clamping the index
used to zero on invalid system call numbers, and using the csdb
speculative barrier.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 1d4238c56f9816ce0f9c8dbe42d7f2ad81cb6613 upstream.
Add an implementation of the array_index_mask_nospec() function for
mitigating Spectre variant 1 throughout the kernel.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit a78d156587931a2c3b354534aa772febf6c9e855 upstream.
Add assembly and C macros for the new CSDB instruction.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit add5609877c6785cc002c6ed7e008b1d61064439 upstream.
Report support for SMCCC_ARCH_WORKAROUND_1 to KVM guests for affected
CPUs.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit b800acfc70d9fb81fbd6df70f2cf5e20f70023d0 upstream.
We want SMCCC_ARCH_WORKAROUND_1 to be fast. As fast as possible.
So let's intercept it as early as we can by testing for the
function call number as soon as we've identified a HVC call
coming from the guest.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 3c908e16396d130608e831b7fac4b167a2ede6ba upstream.
Include Brahma B15 in the Spectre v2 KVM workarounds.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 0c47ac8cd157727e7a532d665d6fb1b5fd333977 upstream.
In order to avoid aliasing attacks against the branch predictor
on Cortex-A15, let's invalidate the BTB on guest exit, which can
only be done by invalidating the icache (with ACTLR[0] being set).
We use the same hack as for A12/A17 to perform the vector decoding.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 3f7e8e2e1ebda787f156ce46e3f0a9ce2833fa4f upstream.
In order to avoid aliasing attacks against the branch predictor,
let's invalidate the BTB on guest exit. This is made complicated
by the fact that we cannot take a branch before invalidating the
BTB.
We only apply this to A12 and A17, which are the only two ARM
cores on which this useful.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit c44f366ea7c85e1be27d08f2f0880f4120698125 upstream.
Warn at error level if the context switching function is not what we
are expecting. This can happen with big.Little systems, which we
currently do not support.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 10115105cb3aa17b5da1cb726ae8dd5f6854bd93 upstream.
Commit 6282e916f774e37845c65d1eae9f8c649004f033 upstream.
Add firmware based hardening for cores that require more complex
handling in firmware.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit f5fe12b1eaee220ce62ff9afb8b90929c396595f upstream.
In order to prevent aliasing attacks on the branch predictor,
invalidate the BTB or instruction cache on CPUs that are known to be
affected when taking an abort on a address that is outside of a user
task limit:
Cortex A8, A9, A12, A17, A73, A75: flush BTB.
Cortex A15, Brahma B15: invalidate icache.
If the IBE bit is not set, then there is little point to enabling the
workaround.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit e388b80288aade31135aca23d32eee93dd106795 upstream.
When the branch predictor hardening is enabled, firmware must have set
the IBE bit in the auxiliary control register. If this bit has not
been set, the Spectre workarounds will not be functional.
Add validation that this bit is set, and print a warning at alert level
if this is not the case.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 06c23f5ffe7ad45b908d0fff604dae08a7e334b9 upstream.
Required manual merge of arch/arm/mm/proc-v7.S.
Harden the branch predictor against Spectre v2 attacks on context
switches for ARMv7 and later CPUs. We do this by:
Cortex A9, A12, A17, A73, A75: invalidating the BTB.
Cortex A15, Brahma B15: invalidating the instruction cache.
Cortex A57 and Cortex A72 are not addressed in this patch.
Cortex R7 and Cortex R8 are also not addressed as we do not enforce
memory protection on these cores.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit c58d237d0852a57fde9bc2c310972e8f4e3d155d upstream.
Add a Kconfig symbol for CPUs which are vulnerable to the Spectre
attacks.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 9d3a04925deeabb97c8e26d940b501a2873e8af3 upstream.
Add support for per-processor bug checking - each processor function
descriptor gains a function pointer for this check, which must not be
an __init function. If non-NULL, this will be called whenever a CPU
enters the kernel via which ever path (boot CPU, secondary CPU startup,
CPU resuming, etc.)
This allows processor specific bug checks to validate that workaround
bits are properly enabled by firmware via all entry paths to the kernel.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 26602161b5ba795928a5a719fe1d5d9f2ab5c3ef upstream.
Check for CPU bugs when secondary processors are being brought online,
and also when CPUs are resuming from a low power mode. This gives an
opportunity to check that processor specific bug workarounds are
correctly enabled for all paths that a CPU re-enters the kernel.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit a5b9177f69329314721aa7022b7e69dab23fa1f0 upstream.
Prepare the processor bug infrastructure so that it can be expanded to
check for per-processor bugs.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit f5683e76f35b4ec5891031b6a29036efe0a1ff84 upstream.
Add CPU part numbers for Cortex A53, A57, A72, A73, A75 and the
Broadcom Brahma B15 CPU.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d135b8b5060ea91dd751ff172d179eb4eab1e966 upstream.
Clang tries to warn when there's a mismatch between an operand's size,
and the size of the register it is held in, as this may indicate a bug.
Specifically, clang warns when the operand's type is less than 64 bits
wide, and the register is used unqualified (i.e. %N rather than %xN or
%wN).
Unfortunately clang can generate these warnings for unreachable code.
For example, for code like:
do { \
typeof(*(ptr)) __v = (v); \
switch(sizeof(*(ptr))) { \
case 1: \
// assume __v is 1 byte wide \
asm ("{op}b %w0" : : "r" (v)); \
break; \
case 8: \
// assume __v is 8 bytes wide \
asm ("{op} %0" : : "r" (v)); \
break; \
}
while (0)
... if op() were passed a char value and pointer to char, clang may
produce a warning for the unreachable case where sizeof(*(ptr)) is 8.
For the same reasons, clang produces warnings when __put_user_err() is
used for types that are less than 64 bits wide.
We could avoid this with a cast to a fixed-width type in each of the
cases. However, GCC will then warn that pointer types are being cast to
mismatched integer sizes (in unreachable paths).
Another option would be to use the same union trickery as we do for
__smp_store_release() and __smp_load_acquire(), but this is fairly
invasive.
Instead, this patch suppresses the clang warning by using an x modifier
in the assembly for the 8 byte case of __put_user_err(). No additional
work is necessary as the value has been cast to typeof(*(ptr)), so the
compiler will have performed any necessary extension for the reachable
case.
For consistency, __get_user_err() is also updated to use the x modifier
for its 8 byte case.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8c97023cf0518f172b8cb7a9fffc28b89401abbf upstream.
Commit 971a69db7dc0 ("Xen: don't warn about 2-byte wchar_t in efi")
added the --no-wchar-size-warning to the Makefile to avoid this
harmless warning:
arm-linux-gnueabi-ld: warning: drivers/xen/efi.o uses 2-byte wchar_t yet the output is to use 4-byte wchar_t; use of wchar_t values across objects may fail
Changing kbuild to use thin archives instead of recursive linking
unfortunately brings the same warning back during the final link.
The kernel does not use wchar_t string literals at this point, and
xen does not use wchar_t at all (only efi_char16_t), so the flag
has no effect, but as pointed out by Jan Beulich, adding a wchar_t
string literal would be bad here.
Since wchar_t is always defined as u16, independent of the toolchain
default, always passing -fshort-wchar is correct and lets us
remove the Xen specific hack along with fixing the warning.
Link: https://patchwork.kernel.org/patch/9275217/
Fixes: 971a69db7dc0 ("Xen: don't warn about 2-byte wchar_t in efi")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9e8730b178a2472fca3123e909d6e69cc8127778 upstream.
With the following commit:
8f91869766c0 ("x86/build: Fix stack alignment for CLang")
cc-option is only used to determine the name of the stack alignment option
supported by the compiler, but not to verify that the actual parameter
<option>=N is valid in combination with the other CFLAGS.
This causes problems (as reported by the kbuild robot) with older GCC versions
which only support stack alignment on a boundary of 16 bytes or higher.
Also use (__)cc_option to add the stack alignment option to CFLAGS to
make sure only valid options are added.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bernhard.Rosenkranzer@linaro.org
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Davidson <md@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hines <srhines@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dianders@chromium.org
Fixes: 8f91869766c0 ("x86/build: Fix stack alignment for CLang")
Link: http://lkml.kernel.org/r/20170817182047.176752-1-mka@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8f91869766c00622b2eaa8ee567db4f333b78c1a upstream.
Commit:
d77698df39a5 ("x86/build: Specify stack alignment for clang")
intended to use the same stack alignment for clang as with gcc.
The two compilers use different options to configure the stack alignment
(gcc: -mpreferred-stack-boundary=n, clang: -mstack-alignment=n).
The above commit assumes that the clang option uses the same parameter
type as gcc, i.e. that the alignment is specified as 2^n. However clang
interprets the value of this option literally to use an alignment of n,
in consequence the stack remains misaligned.
Change the values used with -mstack-alignment to be the actual alignment
instead of a power of two.
cc-option isn't used here with the typical pattern of KBUILD_CFLAGS +=
$(call cc-option ...). The reason is that older gcc versions don't
support the -mpreferred-stack-boundary option, since cc-option doesn't
verify whether the alternative option is valid it would incorrectly
select the clang option -mstack-alignment..
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bernhard.Rosenkranzer@linaro.org
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Davidson <md@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hines <srhines@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dianders@chromium.org
Link: http://lkml.kernel.org/r/20170817004740.170588-1-mka@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 91ee5b21ee026c49e4e7483de69b55b8b47042be upstream.
Clang may emit absolute symbol references when building in non-PIC mode,
even when using the default 'small' code model, which is already mostly
position independent to begin with, due to its use of adrp/add pairs
that have a relative range of +/- 4 GB. The remedy is to pass the -fpie
flag, which can be done safely now that the code has been updated to avoid
GOT indirections (which may be emitted due to the compiler assuming that
the PIC/PIE code may end up in a shared library that is subject to ELF
symbol preemption)
Passing -fpie when building code that needs to execute at an a priori
unknown offset is arguably an improvement in any case, and given that
the recent visibility changes allow the PIC build to pass with GCC as
well, let's add -fpie for all arm64 builds rather than only for Clang.
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170818194947.19347-5-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 696204faa6e8a318320ebb49d9fa69bc8275644d upstream.
The build commands for the ARM and arm64 EFI stubs strip the .debug
sections and other sections that may legally contain absolute relocations,
in order to inspect the remaining sections for the presence of such
relocations.
This leaves us without debugging symbols in the stub for no good reason,
considering that these sections are omitted from the kernel binary anyway,
and that these relocations are thus only consumed by users of the ELF
binary, such as debuggers.
So move to 'strip' for performing the relocation check, and if it succeeds,
invoke objcopy as before, but leaving the .debug sections in place. Note
that these sections may refer to ksymtab/kcrctab contents, so leave those
in place as well.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1485868902-20401-11-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0426a4e68f18d75515414361de9e3e1445d2644e upstream.
To prevent the compiler from emitting absolute references to the section
markers when running in PIC mode, override the visibility to 'hidden' for
all contents of asm/sections.h
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170818194947.19347-4-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 760b61d76da6d6a99eb245ab61abf71ca5415cea upstream.
To prevent the compiler from emitting absolute references to screen_info
when building position independent code, redeclare the symbol with hidden
visibility.
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170818194947.19347-3-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 18d5e6c34a8eda438d5ad8b3b15f42dab01bf05d upstream.
undef memcpy() and friends in boot/string.c so that the functions
defined here will have the correct names, otherwise we end up
up trying to redefine __builtin_memcpy() etc.
Surprisingly, GCC allows this (and, helpfully, discards the
__builtin_ prefix from the function name when compiling it),
but clang does not.
Adding these #undef's appears to preserve what I assume was
the original intent of the code.
Signed-off-by: Michael Davidson <md@google.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bernhard.Rosenkranzer@linaro.org
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170724235155.79255-1-mka@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f4857f4c2ee9aa4e2aacac1a845352b00197fb57 upstream.
Replace the inline asm which exports struct offsets as ELF symbols
with proper const variables exposing the same values. This works
around an issue with Clang which does not interpret the "i" (or "I")
constraints in the same way as GCC.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bfb38988c51e440fd7062ddf3157f7d8b1dd5d70 upstream.
clang generates plenty of these warnings in different parts of the code,
to an extent that the warnings are little more than noise. Disable the
'address-of-packed-member' warning.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d77698df39a512911586834d303275ea5fda74d0 upstream.
For gcc stack alignment is configured with -mpreferred-stack-boundary=N,
clang has the option -mstack-alignment=N for that purpose. Use the same
alignment as with gcc.
If the alignment is not specified clang assumes an alignment of
16 bytes, as required by the standard ABI. However as mentioned in
d9b0cde91c60 ("x86-64, gcc: Use -mpreferred-stack-boundary=3 if
supported") the standard kernel entry on x86-64 leaves the stack
on an 8-byte boundary, as a consequence clang will keep the stack
misaligned.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 032a2c4f65a2f81c93e161a11197ba19bc14a909 upstream.
cc-option is used to enable compiler options for the boot code if they
are available. The macro uses KBUILD_CFLAGS and KBUILD_CPPFLAGS for the
check, however these flags aren't used to build the boot code, in
consequence cc-option can yield wrong results. For example
-mpreferred-stack-boundary=2 is never set with a 64-bit compiler,
since the setting is only valid for 16 and 32-bit binaries. This
is also the case for 32-bit kernel builds, because the option -m32 is
added to KBUILD_CFLAGS after the assignment of REALMODE_CFLAGS.
Use __cc-option instead of cc-option for the boot mode options.
The macro receives the compiler options as parameter instead of using
KBUILD_C*FLAGS, for the boot code we pass REALMODE_CFLAGS.
Also use separate statements for the __cc-option checks instead
of performing them in the initial assignment of REALMODE_CFLAGS since
the variable is an input of the macro.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9f3f1fd299768782465cb32cdf0dd4528d11f26b upstream.
cc-option uses KBUILD_CFLAGS and KBUILD_CPPFLAGS when it determines
whether an option is supported or not. This is fine for options used to
build the kernel itself, however some components like the x86 boot code
use a different set of flags.
Add the new macro __cc-option which is a more generic version of
cc-option with additional parameters. One parameter is the compiler
with which the check should be performed, the other the compiler options
to be used instead KBUILD_C*FLAGS.
Refactor cc-option and hostcc-option to use __cc-option and move
hostcc-option to scripts/Kbuild.include.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fdb2726f4e61c5e3abc052f547d5a5f6c0dc5504 upstream.
aes_ctrby8_avx-x86_64.S uses the C preprocessor for token pasting
of character sequences that are not valid preprocessor tokens.
While this is allowed when preprocessing assembler files it exposes
an incompatibilty between the clang and gcc preprocessors where
clang does not strip leading white space from macro parameters,
leading to the CONCAT(%xmm, i) macro expansion on line 96 resulting
in a token with a space character embedded in it.
While this could be resolved by deleting the offending space character,
the assembler is perfectly capable of doing the token pasting correctly
for itself so we can just get rid of the preprocessor macros.
Signed-off-by: Michael Davidson <md@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2c4fd1ac3ff167c91272dc43c7bfd2269ef61557 upstream.
clang currently does not support these optimizations, only enable them
when they are available.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Davidson <md@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: grundler@chromium.org
Link: http://lkml.kernel.org/r/20170413172609.118122-1-mka@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1f318a8bafcfba9f0d623f4870c4e890fd22e659 upstream.
clang warns about unused inline functions by default:
arch/arm/crypto/aes-cipher-glue.c:68:1: warning: unused function '__inittest' [-Wunused-function]
arch/arm/crypto/aes-cipher-glue.c:69:1: warning: unused function '__exittest' [-Wunused-function]
As these appear in every single module, let's just disable the warnings by marking the
two functions as __maybe_unused.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jessica Yu <jeyu@redhat.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 433db3e260bc8134d4a46ddf20b3668937e12556 upstream.
Add rules to kbuild in order to generate LLVM assembly files with the .ll
extension when using clang.
# from c code
make CC=clang kernel/pid.ll
Signed-off-by: Vinícius Tinti <viniciustinti@gmail.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c3f0d0bc5b01ad90c45276952802455750444b4f upstream.
Clang will warn about unknown warnings but will not return false
unless -Werror is set. GCC will return false if an unknown
warning is passed.
Adding -Werror make both compiler behave the same.
[arnd: it turns out we need the same patch for testing whether -ffunction-sections
works right with gcc. I've build tested extensively with this patch
applied, so let's just merge this one now.]
Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Jan-Simon Möller <dl9pf@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a0ae981eba8f07dbc74bce38fd3a462b69a5bc8e upstream.
Since commit c3f0d0bc5b01 ("kbuild, LLVMLinux: Add -Werror to
cc-option to support clang"), cc-option and friends work nicely
for clang.
However, -Wno-unknown-warning-option makes clang happy with any
unknown warning options even if -Werror is specified.
Once -Wno-unknown-warning-option is added, any succeeding call of
cc-disable-warning is evaluated positive, then unknown warning
options are accepted. This should be dropped.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cf0c3e68aa81f992b0301f62e341b710d385bf68 upstream.
KBuild abuses the asm statement to write to a file and
clang chokes about these invalid asm statements. Hack it
even more by fooling this is actual valid asm code.
[masahiro:
Import Jeroen's work for U-Boot:
http://patchwork.ozlabs.org/patch/375026/
Tweak sed script a little to avoid garbage '#' for GCC case, like
#define NR_PAGEFLAGS 23 /* __NR_PAGEFLAGS # */ ]
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7dd47b95b0f54f2057d40af6e66d477e3fe95d13 upstream.
This part ended up in redundant code after touched by multiple
people.
[1] Commit 3234282f33b2 ("x86, asm: Fix CFI macro invocations to
deal with shortcomings in gas") added parentheses for defined
expressions to support old gas for x86.
[2] Commit a22dcdb0032c ("x86, asm: Fix ancient-GAS workaround")
split the pattern into two to avoid parentheses for non-numeric
expressions.
[3] Commit 95a2f6f72d37 ("Partially revert patch that encloses
asm-offset.h numbers in brackets") removed parentheses from numeric
expressions as well because parentheses in MN10300 assembly have a
special meaning (pointer access).
Apparently, there is a conflict between [1] and [3]. After all,
[3] took precedence, and a long time has passed since then.
Now, merge the two patterns again because the first one is covered
by the other.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ebf003f0cfb3705e60d40dedc3ec949176c741af upstream.
Largely redundant code is used in different places to generate C headers
from offset information extracted from assembly language output.
Consolidate the code in Makefile.lib and use this instead.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
