30 Dec, 2020
2 commits
-
[ Upstream commit 3cce9d44321e460e7c88cdec4e4537a6e9ad7c0d ]
Commit f77ac2e378be9dd6 ("ARM: 9030/1: entry: omit FP emulation for UND
exceptions taken in kernel mode") failed to take into account that there
is in fact a case where we relied on this code path: during boot, the
VFP detection code issues a read of FPSID, which will trigger an undef
exception on cores that lack VFP support.So let's reinstate this logic using an undef hook which is registered
only for the duration of the initcall to vpf_init(), and which sets
VFP_arch to a non-zero value - as before - if no VFP support is present.Fixes: f77ac2e378be9dd6 ("ARM: 9030/1: entry: omit FP emulation for UND ...")
Reported-by: "kernelci.org bot"
Signed-off-by: Ard Biesheuvel
Signed-off-by: Russell King
Signed-off-by: Sasha Levin -
[ Upstream commit f77ac2e378be9dd61eb88728f0840642f045d9d1 ]
There are a couple of problems with the exception entry code that deals
with FP exceptions (which are reported as UND exceptions) when building
the kernel in Thumb2 mode:
- the conditional branch to vfp_kmode_exception in vfp_support_entry()
may be out of range for its target, depending on how the linker decides
to arrange the sections;
- when the UND exception is taken in kernel mode, the emulation handling
logic is entered via the 'call_fpe' label, which means we end up using
the wrong value/mask pairs to match and detect the NEON opcodes.Since UND exceptions in kernel mode are unlikely to occur on a hot path
(as opposed to the user mode version which is invoked for VFP support
code and lazy restore), we can use the existing undef hook machinery for
any kernel mode instruction emulation that is needed, including calling
the existing vfp_kmode_exception() routine for unexpected cases. So drop
the call to call_fpe, and instead, install an undef hook that will get
called for NEON and VFP instructions that trigger an UND exception in
kernel mode.While at it, make sure that the PC correction is accurate for the
execution mode where the exception was taken, by checking the PSR
Thumb bit.Cc: Dmitry Osipenko
Cc: Kees Cook
Fixes: eff8728fe698 ("vmlinux.lds.h: Add PGO and AutoFDO input sections")
Signed-off-by: Ard Biesheuvel
Reviewed-by: Linus Walleij
Reviewed-by: Nick Desaulniers
Signed-off-by: Russell King
Signed-off-by: Sasha Levin
21 Jul, 2020
2 commits
-
The integrated assembler of Clang 10 and earlier do not allow to access
the VFP registers through the coprocessor load/store instructions:
arch/arm/vfp/vfpmodule.c:342:2: error: invalid operand for instruction
fmxr(FPEXC, fpexc & ~(FPEXC_EX|FPEXC_DEX|FPEXC_FP2V|FPEXC_VV|FPEXC_TRAP_MASK));
^
arch/arm/vfp/vfpinstr.h:79:6: note: expanded from macro 'fmxr'
asm("mcr p10, 7, %0, " vfpreg(_vfp_) ", cr0, 0 @ fmxr " #_vfp_ ", %0"
^
:1:6: note: instantiated into assembly here
mcr p10, 7, r0, cr8, cr0, 0 @ fmxr FPEXC, r0
^This has been addressed with Clang 11 [0]. However, to support earlier
versions of Clang and for better readability use of VFP assembler
mnemonics still is preferred.Ideally we would replace this code with the unified assembler language
mnemonics vmrs/vmsr on call sites along with .fpu assembler directives.
The GNU assembler supports the .fpu directive at least since 2.17 (when
documentation has been added). Since Linux requires binutils 2.21 it is
safe to use .fpu directive. However, binutils does not allow to use
FPINST or FPINST2 as an argument to vmrs/vmsr instructions up to
binutils 2.24 (see binutils commit 16d02dc907c5):
arch/arm/vfp/vfphw.S: Assembler messages:
arch/arm/vfp/vfphw.S:162: Error: operand 0 must be FPSID or FPSCR pr FPEXC -- `vmsr FPINST,r6'
arch/arm/vfp/vfphw.S:165: Error: operand 0 must be FPSID or FPSCR pr FPEXC -- `vmsr FPINST2,r8'
arch/arm/vfp/vfphw.S:235: Error: operand 1 must be a VFP extension System Register -- `vmrs r3,FPINST'
arch/arm/vfp/vfphw.S:238: Error: operand 1 must be a VFP extension System Register -- `vmrs r12,FPINST2'Use as-instr in Kconfig to check if FPINST/FPINST2 can be used. If they
can be used make use of .fpu directives and UAL VFP mnemonics for
register access.This allows to build vfpmodule.c with Clang and its integrated assembler.
[0] https://reviews.llvm.org/D59733
Link: https://github.com/ClangBuiltLinux/linux/issues/905
Signed-off-by: Stefan Agner
Signed-off-by: Russell King -
Explicit FPU selection has been introduced in commit 1a6be26d5b1a
("[ARM] Enable VFP to be built when non-VFP capable CPUs are selected")
to make use of assembler mnemonics for VFP instructions.However, clang currently does not support passing assembler flags
like this and errors out with:
clang-10: error: the clang compiler does not support '-Wa,-mfpu=softvfp+vfp'Make use of the .fpu assembler directives to select the floating point
hardware selectively. Also use the new unified assembler language
mnemonics. This allows to build these procedures with Clang.Link: https://github.com/ClangBuiltLinux/linux/issues/762
Signed-off-by: Stefan Agner
Signed-off-by: Russell King
19 Jun, 2019
1 commit
-
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundationthis program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner
Reviewed-by: Enrico Weigelt
Reviewed-by: Kate Stewart
Reviewed-by: Allison Randal
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman
21 May, 2019
1 commit
-
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:GPL-2.0-only
Signed-off-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
15 Nov, 2018
1 commit
-
Pull ARM fix from Russell King:
"It was noticed that one of Julien's patches contained an error, this
fixes that up"* 'spectre' of git://git.armlinux.org.uk/~rmk/linux-arm:
ARM: 8810/1: vfp: Fix wrong assignement to ufp_exc
12 Nov, 2018
1 commit
-
In vfp_preserve_user_clear_hwstate, ufp_exc->fpinst2 gets assigned to
itself. It should actually be hwstate->fpinst2 that gets assigned to the
ufp_exc field.Fixes commit 3aa2df6ec2ca6bc143a65351cca4266d03a8bc41 ("ARM: 8791/1:
vfp: use __copy_to_user() when saving VFP state").Reported-by: David Binderman
Signed-off-by: Julien Thierry
Signed-off-by: Russell King
24 Oct, 2018
1 commit
-
…iederm/user-namespace
Pull siginfo updates from Eric Biederman:
"I have been slowly sorting out siginfo and this is the culmination of
that work.The primary result is in several ways the signal infrastructure has
been made less error prone. The code has been updated so that manually
specifying SEND_SIG_FORCED is never necessary. The conversion to the
new siginfo sending functions is now complete, which makes it
difficult to send a signal without filling in the proper siginfo
fields.At the tail end of the patchset comes the optimization of decreasing
the size of struct siginfo in the kernel from 128 bytes to about 48
bytes on 64bit. The fundamental observation that enables this is by
definition none of the known ways to use struct siginfo uses the extra
bytes.This comes at the cost of a small user space observable difference.
For the rare case of siginfo being injected into the kernel only what
can be copied into kernel_siginfo is delivered to the destination, the
rest of the bytes are set to 0. For cases where the signal and the
si_code are known this is safe, because we know those bytes are not
used. For cases where the signal and si_code combination is unknown
the bits that won't fit into struct kernel_siginfo are tested to
verify they are zero, and the send fails if they are not.I made an extensive search through userspace code and I could not find
anything that would break because of the above change. If it turns out
I did break something it will take just the revert of a single change
to restore kernel_siginfo to the same size as userspace siginfo.Testing did reveal dependencies on preferring the signo passed to
sigqueueinfo over si->signo, so bit the bullet and added the
complexity necessary to handle that case.Testing also revealed bad things can happen if a negative signal
number is passed into the system calls. Something no sane application
will do but something a malicious program or a fuzzer might do. So I
have fixed the code that performs the bounds checks to ensure negative
signal numbers are handled"* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (80 commits)
signal: Guard against negative signal numbers in copy_siginfo_from_user32
signal: Guard against negative signal numbers in copy_siginfo_from_user
signal: In sigqueueinfo prefer sig not si_signo
signal: Use a smaller struct siginfo in the kernel
signal: Distinguish between kernel_siginfo and siginfo
signal: Introduce copy_siginfo_from_user and use it's return value
signal: Remove the need for __ARCH_SI_PREABLE_SIZE and SI_PAD_SIZE
signal: Fail sigqueueinfo if si_signo != sig
signal/sparc: Move EMT_TAGOVF into the generic siginfo.h
signal/unicore32: Use force_sig_fault where appropriate
signal/unicore32: Generate siginfo in ucs32_notify_die
signal/unicore32: Use send_sig_fault where appropriate
signal/arc: Use force_sig_fault where appropriate
signal/arc: Push siginfo generation into unhandled_exception
signal/ia64: Use force_sig_fault where appropriate
signal/ia64: Use the force_sig(SIGSEGV,...) in ia64_rt_sigreturn
signal/ia64: Use the generic force_sigsegv in setup_frame
signal/arm/kvm: Use send_sig_mceerr
signal/arm: Use send_sig_fault where appropriate
signal/arm: Use force_sig_fault where appropriate
...
10 Oct, 2018
1 commit
05 Oct, 2018
1 commit
-
Use __copy_to_user() rather than __put_user_error() for individual
members when saving VFP state.
This has the benefit of disabling/enabling PAN once per copied struct
intead of once per write.Signed-off-by: Julien Thierry
Signed-off-by: Russell King
28 Sep, 2018
1 commit
-
Signed-off-by: "Eric W. Biederman"
13 Aug, 2018
1 commit
-
Conflicts:
arch/arm/include/asm/uaccess.hSigned-off-by: Russell King
03 Aug, 2018
1 commit
-
__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
Signed-off-by: Russell King
30 Jul, 2018
1 commit
-
Since commit 799c43415442 ("kbuild: thin archives make default for
all archs"), $(AR) is used instead of $(LD) to combine object files.The following code in arch/arm/vfp/Makefile:
LDFLAGS +=--no-warn-mismatch
... is no longer used.
Also, arch/arm/Makefile already guards arch/arm/vfp/ by a boolean
symbol, CONFIG_VFP, like this:core-$(CONFIG_VFP) += arch/arm/vfp/
So, $(CONFIG_VFP) is always evaluated to y in arch/arm/vfp/Makefile.
There is no point to use pseudo object, vfp.o, which never becomes
a module. Add all objects to obj-y directly.Signed-off-by: Masahiro Yamada
Signed-off-by: Russell King
05 Jun, 2018
1 commit
-
…iederm/user-namespace
Pull siginfo updates from Eric Biederman:
"This set of changes close the known issues with setting si_code to an
invalid value, and with not fully initializing struct siginfo. There
remains work to do on nds32, arc, unicore32, powerpc, arm, arm64, ia64
and x86 to get the code that generates siginfo into a simpler and more
maintainable state. Most of that work involves refactoring the signal
handling code and thus careful code review.Also not included is the work to shrink the in kernel version of
struct siginfo. That depends on getting the number of places that
directly manipulate struct siginfo under control, as it requires the
introduction of struct kernel_siginfo for the in kernel things.Overall this set of changes looks like it is making good progress, and
with a little luck I will be wrapping up the siginfo work next
development cycle"* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
signal/sh: Stop gcc warning about an impossible case in do_divide_error
signal/mips: Report FPE_FLTUNK for undiagnosed floating point exceptions
signal/um: More carefully relay signals in relay_signal.
signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR}
signal: Remove unncessary #ifdef SEGV_PKUERR in 32bit compat code
signal/signalfd: Add support for SIGSYS
signal/signalfd: Remove __put_user from signalfd_copyinfo
signal/xtensa: Use force_sig_fault where appropriate
signal/xtensa: Consistenly use SIGBUS in do_unaligned_user
signal/um: Use force_sig_fault where appropriate
signal/sparc: Use force_sig_fault where appropriate
signal/sparc: Use send_sig_fault where appropriate
signal/sh: Use force_sig_fault where appropriate
signal/s390: Use force_sig_fault where appropriate
signal/riscv: Replace do_trap_siginfo with force_sig_fault
signal/riscv: Use force_sig_fault where appropriate
signal/parisc: Use force_sig_fault where appropriate
signal/parisc: Use force_sig_mceerr where appropriate
signal/openrisc: Use force_sig_fault where appropriate
signal/nios2: Use force_sig_fault where appropriate
...
20 May, 2018
1 commit
-
Commit 7771c6645700 ("signal/arm: Document conflicts with SI_USER and
SIGFPE") broke the siginfo structure for userspace triggered signals,
causing the strace testsuite to regress. Fix this by eliminating
the FPE_FIXME definition (which is at the root of the breakage) and
use FPE_FLTINV instead for the case where the hardware appears to be
reporting nonsense.Fixes: 7771c6645700 ("signal/arm: Document conflicts with SI_USER and SIGFPE")
Suggested-by: Linus Torvalds
Signed-off-by: Russell King
25 Apr, 2018
1 commit
-
Call clear_siginfo to ensure every stack allocated siginfo is properly
initialized before being passed to the signal sending functions.Note: It is not safe to depend on C initializers to initialize struct
siginfo on the stack because C is allowed to skip holes when
initializing a structure.The initialization of struct siginfo in tracehook_report_syscall_exit
was moved from the helper user_single_step_siginfo into
tracehook_report_syscall_exit itself, to make it clear that the local
variable siginfo gets fully initialized.In a few cases the scope of struct siginfo has been reduced to make it
clear that siginfo siginfo is not used on other paths in the function
in which it is declared.Instances of using memset to initialize siginfo have been replaced
with calls clear_siginfo for clarity.Signed-off-by: "Eric W. Biederman"
24 Mar, 2018
1 commit
-
Commit 384b38b66947 ("ARM: 7873/1: vfp: clear vfp_current_hw_state
for dying cpu") fixed the cpu dying notifier by clearing
vfp_current_hw_state[]. However commit e5b61bafe704 ("arm: Convert VFP
hotplug notifiers to state machine") incorrectly used the original
vfp_force_reload() function in the cpu dying notifier.Fix it by going back to clearing vfp_current_hw_state[].
Fixes: e5b61bafe704 ("arm: Convert VFP hotplug notifiers to state machine")
Cc: linux-stable
Reported-by: Kohji Okuno
Signed-off-by: Fabio Estevam
Signed-off-by: Russell King
13 Jan, 2018
1 commit
-
Setting si_code to 0 results in a userspace seeing an si_code of 0.
This is the same si_code as SI_USER. Posix and common sense requires
that SI_USER not be a signal specific si_code. As such this use of 0
for the si_code is a pretty horribly broken ABI.Further use of si_code == 0 guaranteed that copy_siginfo_to_user saw a
value of __SI_KILL and now sees a value of SIL_KILL with the result
that uid and pid fields are copied and which might copying the si_addr
field by accident but certainly not by design. Making this a very
flakey implementation.Utilizing FPE_FIXME, siginfo_layout will now return SIL_FAULT and the
appropriate fields will be reliably copied.Possible ABI fixes includee:
- Send the signal without siginfo
- Don't generate a signal
- Possibly assign and use an appropriate si_code
- Don't handle cases which can't happenCc: Russell King
Cc: linux-arm-kernel@lists.infradead.org
Ref: 451436b7bbb2 ("[ARM] Add support code for ARM hardware vector floating point")
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Signed-off-by: "Eric W. Biederman"
02 Mar, 2017
1 commit
-
We are going to split out of , which
will have to be picked up from other headers and a couple of .c files.Create a trivial placeholder file that just
maps to to make this patch obviously correct and
bisectable.Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar
25 Dec, 2016
1 commit
-
When the state names got added a script was used to add the extra argument
to the calls. The script basically converted the state constant to a
string, but the cleanup to convert these strings into meaningful ones did
not happen.Replace all the useless strings with 'subsys/xxx/yyy:state' strings which
are used in all the other places already.Signed-off-by: Thomas Gleixner
Cc: Peter Zijlstra
Cc: Sebastian Siewior
Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de
Signed-off-by: Thomas Gleixner
22 Nov, 2016
1 commit
-
This is good for consistency even if there is no difference in compiled
code. LTO might rely on this eventually. No need to preserve the extern
attribute as it is the default with function prototypes.Signed-off-by: Nicolas Pitre
Signed-off-by: Russell King
15 Jul, 2016
1 commit
-
Straight forward conversion plus commentary why code which is executed
in hotplug callbacks needs to be invoked before installing them.Signed-off-by: Thomas Gleixner
Signed-off-by: Anna-Maria Gleixner
Reviewed-by: Sebastian Andrzej Siewior
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: Russell King
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153335.713612993@linutronix.de
Signed-off-by: Ingo Molnar
21 May, 2016
1 commit
-
We need to call exit_thread from copy_process in a fail path. So make it
accept task_struct as a parameter.[v2]
* s390: exit_thread_runtime_instr doesn't make sense to be called for
non-current tasks.
* arm: fix the comment in vfp_thread_copy
* change 'me' to 'tsk' for task_struct
* now we can change only archs that actually have exit_thread[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jiri Slaby
Cc: "David S. Miller"
Cc: "H. Peter Anvin"
Cc: "James E.J. Bottomley"
Cc: Aurelien Jacquiot
Cc: Benjamin Herrenschmidt
Cc: Catalin Marinas
Cc: Chen Liqin
Cc: Chris Metcalf
Cc: Chris Zankel
Cc: David Howells
Cc: Fenghua Yu
Cc: Geert Uytterhoeven
Cc: Guan Xuetao
Cc: Haavard Skinnemoen
Cc: Hans-Christian Egtvedt
Cc: Heiko Carstens
Cc: Helge Deller
Cc: Ingo Molnar
Cc: Ivan Kokshaysky
Cc: James Hogan
Cc: Jeff Dike
Cc: Jesper Nilsson
Cc: Jiri Slaby
Cc: Jonas Bonn
Cc: Koichi Yasutake
Cc: Lennox Wu
Cc: Ley Foon Tan
Cc: Mark Salter
Cc: Martin Schwidefsky
Cc: Matt Turner
Cc: Max Filippov
Cc: Michael Ellerman
Cc: Michal Simek
Cc: Mikael Starvik
Cc: Paul Mackerras
Cc: Peter Zijlstra
Cc: Ralf Baechle
Cc: Rich Felker
Cc: Richard Henderson
Cc: Richard Kuo
Cc: Richard Weinberger
Cc: Russell King
Cc: Steven Miao
Cc: Thomas Gleixner
Cc: Tony Luck
Cc: Vineet Gupta
Cc: Will Deacon
Cc: Yoshinori Sato
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 May, 2015
1 commit
-
Some platforms might not be able to fully utilize VFP when e.g: one CPU
out of two in a SMP complex lacks a VFP unit. Adding code to migrate
task to the CPU which has a VFP unit would be cumbersome and not
performant, instead, just add the ability to disable VFP.Signed-off-by: Florian Fainelli
21 Nov, 2014
3 commits
-
Convert many (but not all) printk(KERN_* to pr_* to simplify the code.
We take the opportunity to join some printk lines together so we don't
split the message across several lines, and we also add a few levels
to some messages which were previously missing them.Tested-by: Andrew Lunn
Tested-by: Felipe Balbi
Signed-off-by: Russell King -
Stephen Rothwell reports that commit 3f4c9f8f0a20 ("ARM: 8197/1:
vfp: Fix VFPv3 hwcap detection on CPUID based cpus") introduced a
variable unused warning.arch/arm/vfp/vfpmodule.c: In function 'vfp_init':
arch/arm/vfp/vfpmodule.c:725:6: warning: unused variable 'mvfr0'
[-Wunused-variable]
u32 mvfr0;Silence this warning by using IS_ENABLED instead of ifdefs.
Reported-by: Stephen Rothwell
Signed-off-by: Stephen Boyd
Signed-off-by: Russell King -
The subarchitecture field in the fpsid register is 7 bits wide on
ARM CPUs using the CPUID identification scheme, spanning bits 22
to 16. The topmost bit is used to designate that the
subarchitecture designer is not ARM when it is set to 1. On
non-CPUID scheme CPUs the subarchitecture field is only 4 bits
wide and the higher bits are used to indicate no double precision
support (bit 20) and the FTSMX/FLDMX format (bits 21-22).The VFP support code only looks at bits 19-16 to determine the
VFP version. On Qualcomm's processors (Krait and Scorpion) we
should see that we have HWCAP_VFPv3 but we don't because bit 22
is set to 1 to indicate that the subarchitecture is not
implemented by ARM and the rest of the bits are left as 0 because
this is the first subarchitecture that Qualcomm has designed.
Unfortunately we can't just widen the FPSID subarchitecture
bitmask to consider all the bits on a CPUID scheme because there
may be CPUs without the CPUID scheme that have VFP without double
precision support and then the version would be a very wrong and
large number. Instead, update the version detection logic to
consider if the CPU is using the CPUID scheme.If the CPU is using CPUID scheme, use the MVFR registers to
determine what version of VFP is supported. We already do this
for VFPv4, so do something similar for VFPv3 and look for single
or double precision support in MVFR0. Otherwise fall back to
using FPSID to detect VFP support on non-CPUID scheme CPUs. We
know that VFPv3 is only present in CPUs that have support for the
CPUID scheme so this should be equivalent.Tested-by: Rob Clark
Reviewed-by: Will Deacon
Signed-off-by: Stephen Boyd
Signed-off-by: Russell King
18 Nov, 2014
1 commit
-
Certain ARM CPU implementations (e.g. Cortex-A15) may not raise a
floating- point exception whenever deprecated short-vector VFP
instructions are executed. Instead these instructions are treated
as UNALLOCATED. Change the VFP exception handling code to emulate
short-vector instructions even if FPEXC exception bits are not
set.Signed-off-by: Stepan Moskovchenko
Tested-by: Will Deacon
Tested-by: Rob Clark
Signed-off-by: Stephen Boyd
Signed-off-by: Russell King
18 Jul, 2014
1 commit
-
ARMv6 and greater introduced a new instruction ("bx") which can be used
to return from function calls. Recent CPUs perform better when the
"bx lr" instruction is used rather than the "mov pc, lr" instruction,
and this sequence is strongly recommended to be used by the ARM
architecture manual (section A.4.1.1).We provide a new macro "ret" with all its variants for the condition
code which will resolve to the appropriate instruction.Rather than doing this piecemeal, and miss some instances, change all
the "mov pc" instances to use the new macro, with the exception of
the "movs" instruction and the kprobes code. This allows us to detect
the "mov pc, lr" case and fix it up - and also gives us the possibility
of deploying this for other registers depending on the CPU selection.Reported-by: Will Deacon
Tested-by: Stephen Warren # Tegra Jetson TK1
Tested-by: Robert Jarzmik # mioa701_bootresume.S
Tested-by: Andrew Lunn # Kirkwood
Tested-by: Shawn Guo
Tested-by: Tony Lindgren # OMAPs
Tested-by: Gregory CLEMENT # Armada XP, 375, 385
Acked-by: Sekhar Nori # DaVinci
Acked-by: Christoffer Dall # kvm/hyp
Acked-by: Haojian Zhuang # PXA3xx
Acked-by: Stefano Stabellini # Xen
Tested-by: Uwe Kleine-König # ARMv7M
Tested-by: Simon Horman # Shmobile
Signed-off-by: Russell King
05 Jun, 2014
1 commit
25 Apr, 2014
1 commit
-
The Undef abort handler in the kernel reads the undefined instruction
from user space. If the page table was modified from another CPU, the
user access could fail and do_page_fault() will be executed with
interrupts disabled. This can potentially deadlock on ARM11MPCore or on
Cortex-A15 with erratum 798181 workaround enabled (both implying IPI for
TLB maintenance with page table lock held).This patch enables the IRQs in __und_usr before attempting to read the
instruction from user space.Signed-off-by: Catalin Marinas
Tested-by: Arun KS
Cc: Hartley Sweeten
Cc: Ryan Mallon
Signed-off-by: Russell King
15 Apr, 2014
1 commit
-
The emulation for single and double precision multiply accumulate
instructions correctly normalised any denormal values in the operand
registers, but failed to normalise the destination (accumulator)
register.This fixes https://bugzilla.kernel.org/show_bug.cgi?id=70501
Signed-off-by: Jay Foad
Signed-off-by: Russell King
09 Apr, 2014
2 commits
-
The patch adds asm macros for inc_preempt_count and dec_preempt_count_ti
(which also gets the current thread_info) instead of open-coding them in
arch/arm/vfp/*.S files.Signed-off-by: Catalin Marinas
Tested-by: Arun KS
Signed-off-by: Russell King -
asm/assembler.h is a better place for this macro since it is used by
asm files outside arch/arm/kernel/Signed-off-by: Catalin Marinas
Tested-by: Arun KS
Signed-off-by: Russell King
31 Oct, 2013
1 commit
-
The CPU_DYING notifier is called by cpu stopper task which
does not own the context held in the VFP hardware. Calling
vfp_force_reload() has no effect.
Replace it with clearing vfp_current_hw_state.Signed-off-by: Yuanyuan Zhong
Signed-off-by: Russell King
09 Jul, 2013
3 commits
-
In order to safely support the use of NEON instructions in
kernel mode, some precautions need to be taken:
- the userland context that may be present in the registers (even
if the NEON/VFP is currently disabled) must be stored under the
correct task (which may not be 'current' in the UP case),
- to avoid having to keep track of additional vfpstates for the
kernel side, disallow the use of NEON in interrupt context
and run with preemption disabled,
- after use, re-enable preemption and re-enable the lazy restore
machinery by disabling the NEON/VFP unit.This patch adds the functions kernel_neon_begin() and
kernel_neon_end() which take care of the above. It also adds
the Kconfig symbol KERNEL_MODE_NEON to enable it.Signed-off-by: Ard Biesheuvel
Acked-by: Nicolas Pitre -
The support code in vfp_support_entry does not care whether the
exception that caused it to be invoked occurred in kernel mode or
in user mode. However, neither condition that could trigger this
exception (lazy restore and VFP bounce to support code) is
currently allowable in kernel mode.In either case, print a message describing the condition before
letting the undefined instruction handler run its course and trigger
an oops.Signed-off-by: Ard Biesheuvel
Acked-by: Nicolas Pitre -
In order to use the NEON unit in the kernel, we should
initialize it a bit earlier in the boot process so NEON users
that like to do a quick benchmark at load time (like the
xor_blocks or RAID-6 code) find the NEON/VFP unit already
enabled.Replaced late_initcall() with core_initcall().
Signed-off-by: Ard Biesheuvel
Acked-by: Nicolas Pitre
