summaryrefslogtreecommitdiff
path: root/arch/arm/vfp
AgeCommit message (Collapse)Author
2018-11-14Merge branch 'spectre' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds
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
2018-11-12ARM: 8810/1: vfp: Fix wrong assignement to ufp_excJulien Thierry
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 <dcb314@hotmail.com> Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-10-24Merge branch 'siginfo-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/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 ...
2018-10-10Merge branches 'fixes', 'misc' and 'spectre' into for-nextRussell King
2018-10-05ARM: 8791/1: vfp: use __copy_to_user() when saving VFP stateJulien Thierry
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 <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-09-27signal/arm: Use send_sig_fault where appropriateEric W. Biederman
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-08-13Merge branches 'fixes', 'misc' and 'spectre' into for-linusRussell King
Conflicts: arch/arm/include/asm/uaccess.h Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-08-02ARM: vfp: use __copy_from_user() when restoring VFP stateRussell King
__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>
2018-07-30ARM: 8782/1: vfp: clean up arch/arm/vfp/MakefileMasahiro Yamada
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 <yamada.masahiro@socionext.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-06-04Merge branch 'siginfo-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/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 ...
2018-05-19ARM: fix kill( ,SIGFPE) breakageRussell King
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 <torvalds@linux-foundation.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-04-25signal: Ensure every siginfo we send has all bits initializedEric W. Biederman
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" <ebiederm@xmission.com>
2018-03-24ARM: 8746/1: vfp: Go back to clearing vfp_current_hw_state[]Fabio Estevam
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 <stable@vger.kernel.org> Reported-by: Kohji Okuno <okuno.kohji@jp.panasonic.com> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-01-12signal/arm: Document conflicts with SI_USER and SIGFPEEric W. Biederman
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 happen Cc: Russell King <rmk@flint.arm.linux.org.uk> 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" <ebiederm@xmission.com>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/signal.h> We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/signal.h> file that just maps to <linux/sched.h> 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 <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-25cpu/hotplug: Cleanup state namesThomas Gleixner
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 <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-22ARM: 8629/1: vfp: properly tag assembly function declarations in C codeNicolas Pitre
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 <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-07-15arm: Convert VFP hotplug notifiers to state machineThomas Gleixner
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 <tglx@linutronix.de> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> 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 <mingo@kernel.org>
2016-05-20exit_thread: accept a task parameter to be exitedJiri Slaby
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 <jslaby@suse.cz> Cc: "David S. Miller" <davem@davemloft.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen Liqin <liqin.linux@gmail.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Chris Zankel <chris@zankel.net> Cc: David Howells <dhowells@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Jonas Bonn <jonas@southpole.se> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mikael Starvik <starvik@axis.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@arm.linux.org.uk> Cc: Steven Miao <realmz6@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-20ARM: vfp: Add vfp_disable for problematic platformsFlorian Fainelli
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 <f.fainelli@gmail.com>
2014-11-21ARM: convert printk(KERN_* to pr_*Russell King
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 <andrew@lunn.ch> Tested-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-11-21ARM: 8215/1: vfp: Silence mvfr0 variable unused warningStephen Boyd
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 <sfr@canb.auug.org.au> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-11-21ARM: 8197/1: vfp: Fix VFPv3 hwcap detection on CPUID based cpusStephen Boyd
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 <robdclark@gmail.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-11-17ARM: 8195/1: vfp: Bounce undefined instructions in vectored modeStepan Moskovchenko
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 <stepanm@codeaurora.org> Tested-by: Will Deacon <will.deacon@arm.com> Tested-by: Rob Clark <robdclark@gmail.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-18ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+Russell King
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 <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-06-05Merge branches 'alignment', 'fixes', 'l2c' (early part) and 'misc' into for-nextRussell King
2014-04-25ARM: 8036/1: Enable IRQs before attempting to read user space in __und_usrCatalin Marinas
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 <catalin.marinas@arm.com> Tested-by: Arun KS <getarunks@gmail.com> Cc: Hartley Sweeten <hsweeten@visionengravers.com> Cc: Ryan Mallon <rmallon@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-04-14ARM: 8026/1: Fix emulation of multiply accumulate instructionsJay Foad
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 <jay.foad@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-04-09ARM: 8018/1: Add {inc,dec}_preempt_count asm macrosCatalin Marinas
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 <catalin.marinas@arm.com> Tested-by: Arun KS <getarunks@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-04-09ARM: 8017/1: Move asm macro get_thread_info to asm/assembler.hCatalin Marinas
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 <catalin.marinas@arm.com> Tested-by: Arun KS <getarunks@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-10-30ARM: 7873/1: vfp: clear vfp_current_hw_state for dying cpuYuanyuan Zhong
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 <zyy@motorola.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-07-08ARM: add support for kernel mode NEONArd Biesheuvel
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 <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org>
2013-07-08ARM: be strict about FP exceptions in kernel modeArd Biesheuvel
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 <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org>
2013-07-08ARM: move VFP init to an earlier boot stageArd Biesheuvel
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 <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org>
2013-05-22ARM: 7729/1: vfp: ensure VFP_arch is non-zero when VFP is not supportedWill Deacon
Commit d3f79584a8b5 ("ARM: cleanup undefined instruction entry code") improved the register scheduling when handling undefined instructions. A side effect of this is that r5 is now used as a temporary, whilst the VFP probing code relies on r5 containing a non-zero value when VFP is not supported. This patch fixes the VFP detection code so that we don't rely on the contents of r5. Without this patch, Linux dies loudly on CPUs without VFP support. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-03-01ARM: Fix broken commit 0cc41e4a21d43 corrupting kernel messagesRussell King
Commit 0cc41e4a21d43 (arch: remove direct definitions of KERN_<LEVEL> uses) is broken - not enough thought was put into changing: .asciz "string" to .asciz "string1" "string2" The problem is that each string gets _separately_ NUL terminated, so the result is a string containing: "string1\0string2\0" rather than: "string1string2\0" With our new printk levels, this ends up as - eg, KERN_DEBUG "string": 0x01 0x00 0x07 0x00 "string" 0x00 which produces lots of \x01 in the kernel log. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-02-25ARM: VFP: fix emulation of second VFP instructionRussell King
Martin Storsjö reports that the sequence: ee312ac1 vsub.f32 s4, s3, s2 ee702ac0 vsub.f32 s5, s1, s0 e59f0028 ldr r0, [pc, #40] ee111a90 vmov r1, s3 on Raspberry Pi (implementor 41 architecture 1 part 20 variant b rev 5) where s3 is a denormal and s2 is zero results in incorrect behaviour - the instruction "vsub.f32 s5, s1, s0" is not executed: VFP: bounce: trigger ee111a90 fpexc d0000780 VFP: emulate: INST=0xee312ac1 SCR=0x00000000 ... As we can see, the instruction triggering the exception is the "vmov" instruction, and we emulate the "vsub.f32 s4, s3, s2" but fail to properly take account of the FPEXC_FP2V flag in FPEXC. This is because the test for the second instruction register being valid is bogus, and will always skip emulation of the second instruction. Cc: <stable@vger.kernel.org> Reported-by: Martin Storsjö <martin@martin.st> Tested-by: Martin Storsjö <martin@martin.st> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-01-16ARM: 7627/1: Predicate preempt logic on PREEMP_COUNT not PREEMPT aloneStephen Boyd
Patrik Kluba reports that the preempt count becomes invalid due to the preempt_enable() call being unbalanced with a preempt_disable() call in the vfp assembly routines. This happens because preempt_enable() and preempt_disable() update preempt counts under PREEMPT_COUNT=y but the vfp assembly routines do so under PREEMPT=y. In a configuration where PREEMPT=n and DEBUG_ATOMIC_SLEEP=y, PREEMPT_COUNT=y and so the preempt_enable() call in VFP_bounce() keeps subtracting from the preempt count until it goes negative. Fix this by always using PREEMPT_COUNT to decided when to update preempt counts in the ARM assembly code. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reported-by: Patrik Kluba <pkluba@dension.com> Tested-by: Patrik Kluba <pkluba@dension.com> Cc: <stable@vger.kernel.org> # 2.6.30 Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-10-29ARM: 7566/1: vfp: fix save and restore when running on pre-VFPv3 and ↵Paul Walmsley
CONFIG_VFPv3 set After commit 846a136881b8f73c1f74250bf6acfaa309cab1f2 ("ARM: vfp: fix saving d16-d31 vfp registers on v6+ kernels"), the OMAP 2430SDP board started crashing during boot with omap2plus_defconfig: [ 3.875122] mmcblk0: mmc0:e624 SD04G 3.69 GiB [ 3.915954] mmcblk0: p1 [ 4.086639] Internal error: Oops - undefined instruction: 0 [#1] SMP ARM [ 4.093719] Modules linked in: [ 4.096954] CPU: 0 Not tainted (3.6.0-02232-g759e00b #570) [ 4.103149] PC is at vfp_reload_hw+0x1c/0x44 [ 4.107666] LR is at __und_usr_fault_32+0x0/0x8 It turns out that the context save/restore fix unmasked a latent bug in commit 5aaf254409f8d58229107b59507a8235b715a960 ("ARM: 6203/1: Make VFPv3 usable on ARMv6"). When CONFIG_VFPv3 is set, but the kernel is booted on a pre-VFPv3 core, the code attempts to save and restore the d16-d31 VFP registers. These are only present on non-D16 VFPv3+, so this results in an undefined instruction exception. The code didn't crash before commit 846a136 because the save and restore code was only touching d0-d15, present on all VFP. Fix by implementing a request from Russell King to add a new HWCAP flag that affirmatively indicates the presence of the d16-d31 registers: http://marc.info/?l=linux-arm-kernel&m=135013547905283&w=2 and some feedback from Måns to clarify the name of the HWCAP flag. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Martin <dave.martin@linaro.org> Cc: Måns Rullgård <mans.rullgard@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-08-11ARM: 7483/1: vfp: only advertise VFPv4 in hwcaps if CONFIG_VFPv3 is enabledWill Deacon
VFPv4 support depends on the VFPv3 context save/restore code, so only advertise support in the hwcaps if the kernel can actually handle it. Cc: <stable@vger.kernel.org> # 3.1+ Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-08-01Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-armLinus Torvalds
Pull ARM fixes from Russell King: "This fixes various issues found during July" * 'fixes' of git://git.linaro.org/people/rmk/linux-arm: ARM: 7479/1: mm: avoid NULL dereference when flushing gate_vma with VIVT caches ARM: Fix undefined instruction exception handling ARM: 7480/1: only call smp_send_stop() on SMP ARM: 7478/1: errata: extend workaround for erratum #720789 ARM: 7477/1: vfp: Always save VFP state in vfp_pm_suspend on UP ARM: 7476/1: vfp: only clear vfp state for current cpu in vfp_pm_suspend ARM: 7468/1: ftrace: Trace function entry before updating index ARM: 7467/1: mutex: use generic xchg-based implementation for ARMv6+ ARM: 7466/1: disable interrupt before spinning endlessly ARM: 7465/1: Handle >4GB memory sizes in device tree and mem=size@start option
2012-07-31ARM: Fix undefined instruction exception handlingRussell King
While trying to get a v3.5 kernel booted on the cubox, I noticed that VFP does not work correctly with VFP bounce handling. This is because of the confusion over 16-bit vs 32-bit instructions, and where PC is supposed to point to. The rule is that FP handlers are entered with regs->ARM_pc pointing at the _next_ instruction to be executed. However, if the exception is not handled, regs->ARM_pc points at the faulting instruction. This is easy for ARM mode, because we know that the next instruction and previous instructions are separated by four bytes. This is not true of Thumb2 though. Since all FP instructions are 32-bit in Thumb2, it makes things easy. We just need to select the appropriate adjustment. Do this by moving the adjustment out of do_undefinstr() into the assembly code, as only the assembly code knows whether it's dealing with a 32-bit or 16-bit instruction. Cc: <stable@vger.kernel.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-31ARM: 7477/1: vfp: Always save VFP state in vfp_pm_suspend on UPColin Cross
vfp_pm_suspend should save the VFP state in suspend after any lazy context switch. If it only saves when the VFP is enabled, the state can get lost when, on a UP system: Thread 1 uses the VFP Context switch occurs to thread 2, VFP is disabled but the VFP context is not saved Thread 2 initiates suspend vfp_pm_suspend is called with the VFP disabled, and the unsaved VFP context of Thread 1 in the registers Modify vfp_pm_suspend to save the VFP context whenever vfp_current_hw_state is not NULL. Includes a fix from Ido Yariv <ido@wizery.com>, who pointed out that on SMP systems, the state pointer can be pointing to a freed task struct if a task exited on another cpu, fixed by using #ifndef CONFIG_SMP in the new if clause. Cc: Barry Song <bs14@csr.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ido Yariv <ido@wizery.com> Cc: Daniel Drake <dsd@laptop.org> Cc: Will Deacon <will.deacon@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Colin Cross <ccross@android.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-31ARM: 7476/1: vfp: only clear vfp state for current cpu in vfp_pm_suspendColin Cross
vfp_pm_suspend runs on each cpu, only clear the hardware state pointer for the current cpu. Prevents a possible crash if one cpu clears the hw state pointer when another cpu has already checked if it is valid. Cc: stable@vger.kernel.org Signed-off-by: Colin Cross <ccross@android.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-30arch: remove direct definitions of KERN_<LEVEL> usesJoe Perches
Add #include <linux/kern_levels.h> so that the #define KERN_<LEVEL> macros don't have to be duplicated. Signed-off-by: Joe Perches <joe@perches.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Kay Sievers <kay@vrfy.org> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-21Merge branch 'misc' into for-linusRussell King
Conflicts: arch/arm/kernel/ptrace.c
2012-05-17ARM: 7419/1: vfp: fix VFP flushing regression on sigreturn pathWill Deacon
Commit ff9a184c ("ARM: 7400/1: vfp: clear fpscr length and stride bits on entry to sig handler") flushes the VFP state prior to entering a signal handler so that a VFP operation inside the handler will trap and force a restore of ABI-compliant registers. Reflushing and disabling VFP on the sigreturn path is predicated on the saved thread state indicating that VFP was used by the handler -- however for SMP platforms this is only set on context-switch, making the check unreliable and causing VFP register corruption in userspace since the register values are not necessarily those restored from the sigframe. This patch unconditionally flushes the VFP state after a signal handler. Since we already perform the flush before the handler and the flushing itself happens lazily, the redundant flush when VFP is not used by the handler is essentially a nop. Reported-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-05-12ARM: 7417/1: vfp: ensure preemption is disabled when enabling VFP accessWill Deacon
The vfp_enable function enables access to the VFP co-processor register space (cp10 and cp11) on the current CPU and must be called with preemption disabled. Unfortunately, the vfp_init late initcall does not disable preemption and can lead to an oops during boot if thread migration occurs at the wrong time and we end up attempting to access the FPSID on a CPU with VFP access disabled. This patch fixes the initcall to call vfp_enable from a non-preemptible context on each CPU and adds a BUG_ON(preemptible) to ensure that any similar problems are easily spotted in the future. Cc: stable@vger.kernel.org Reported-by: Hyungwoo Yang <hwoo.yang@gmail.com> Signed-off-by: Hyungwoo Yang <hyungwooy@nvidia.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-05-11ARM: 7415/1: vfp: convert printk's to pr_*'sNicolas Pitre
This is mainly to get rid of the "vfp_pm_suspend: saving vfp state" message flooding the kernel message ring by default. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-04-23ARM: 7400/1: vfp: clear fpscr length and stride bits on entry to sig handlerWill Deacon
The ARM PCS mandates that the length and stride bits of the fpscr are cleared on entry to and return from a public interface. Although signal handlers run asynchronously with respect to the interrupted function, the handler itself expects to run as though it has been called like a normal function. This patch updates the state mirroring the VFP hardware before entry to a signal handler so that it adheres to the PCS. Furthermore, we disable VFP to ensure that we trap on any floating point operation performed by the signal handler and synchronise the hardware appropriately. A check is inserted after the signal handler to avoid redundant flushing if VFP was not used. Reported-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>