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* ARM: prevent tracing IPI_CPU_BACKTRACEArnd Bergmann2019-06-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit be167862ae7dd85c56d385209a4890678e1b0488 ] Patch series "compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING", v3. This patch (of 11): When function tracing for IPIs is enabled, we get a warning for an overflow of the ipi_types array with the IPI_CPU_BACKTRACE type as triggered by raise_nmi(): arch/arm/kernel/smp.c: In function 'raise_nmi': arch/arm/kernel/smp.c:489:2: error: array subscript is above array bounds [-Werror=array-bounds] trace_ipi_raise(target, ipi_types[ipinr]); This is a correct warning as we actually overflow the array here. This patch raise_nmi() to call __smp_cross_call() instead of smp_cross_call(), to avoid calling into ftrace. For clarification, I'm also adding a two new code comments describing how this one is special. The warning appears to have shown up after commit e7273ff49acf ("ARM: 8488/1: Make IPI_CPU_BACKTRACE a "non-secure" SGI"), which changed the number assignment from '15' to '8', but as far as I can tell has existed since the IPI tracepoints were first introduced. If we decide to backport this patch to stable kernels, we probably need to backport e7273ff49acf as well. [yamada.masahiro@socionext.com: rebase on v5.1-rc1] Link: http://lkml.kernel.org/r/20190423034959.13525-2-yamada.masahiro@socionext.com Fixes: e7273ff49acf ("ARM: 8488/1: Make IPI_CPU_BACKTRACE a "non-secure" SGI") Fixes: 365ec7b17327 ("ARM: add IPI tracepoints") # v3.17 Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Mathieu Malaterre <malat@debian.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Stefan Agner <stefan@agner.ch> Cc: Boris Brezillon <bbrezillon@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Richard Weinberger <richard@nod.at> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Marek Vasut <marek.vasut@gmail.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Borislav Petkov <bp@suse.de> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: vdso: Remove dependency with the arch_timer driver internalsMarc Zyngier2019-05-311-0/+2
| | | | | | | | | | | | | | | | | [ Upstream commit 1f5b62f09f6b314c8d70b9de5182dae4de1f94da ] The VDSO code uses the kernel helper that was originally designed to abstract the access between 32 and 64bit systems. It worked so far because this function is declared as 'inline'. As we're about to revamp that part of the code, the VDSO would break. Let's fix it by doing what should have been done from the start, a proper system register access. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: avoid Cortex-A9 livelock on tight dmb loopsRussell King2019-04-052-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 5388a5b82199facacd3d7ac0d05aca6e8f902fed ] machine_crash_nonpanic_core() does this: while (1) cpu_relax(); because the kernel has crashed, and we have no known safe way to deal with the CPU. So, we place the CPU into an infinite loop which we expect it to never exit - at least not until the system as a whole is reset by some method. In the absence of erratum 754327, this code assembles to: b . In other words, an infinite loop. When erratum 754327 is enabled, this becomes: 1: dmb b 1b It has been observed that on some systems (eg, OMAP4) where, if a crash is triggered, the system tries to kexec into the panic kernel, but fails after taking the secondary CPU down - placing it into one of these loops. This causes the system to livelock, and the most noticable effect is the system stops after issuing: Loading crashdump kernel... to the system console. The tested as working solution I came up with was to add wfe() to these infinite loops thusly: while (1) { cpu_relax(); wfe(); } which, without 754327 builds to: 1: wfe b 1b or with 754327 is enabled: 1: dmb wfe b 1b Adding "wfe" does two things depending on the environment we're running under: - where we're running on bare metal, and the processor implements "wfe", it stops us spinning endlessly in a loop where we're never going to do any useful work. - if we're running in a VM, it allows the CPU to be given back to the hypervisor and rescheduled for other purposes (maybe a different VM) rather than wasting CPU cycles inside a crashed VM. However, in light of erratum 794072, Will Deacon wanted to see 10 nops as well - which is reasonable to cover the case where we have erratum 754327 enabled _and_ we have a processor that doesn't implement the wfe hint. So, we now end up with: 1: wfe b 1b when erratum 754327 is disabled, or: 1: dmb nop nop nop nop nop nop nop nop nop nop wfe b 1b when erratum 754327 is enabled. We also get the dmb + 10 nop sequence elsewhere in the kernel, in terminating loops. This is reasonable - it means we get the workaround for erratum 794072 when erratum 754327 is enabled, but still relinquish the dead processor - either by placing it in a lower power mode when wfe is implemented as such or by returning it to the hypervisior, or in the case where wfe is a no-op, we use the workaround specified in erratum 794072 to avoid the problem. These as two entirely orthogonal problems - the 10 nops addresses erratum 794072, and the wfe is an optimisation that makes the system more efficient when crashed either in terms of power consumption or by allowing the host/other VMs to make use of the CPU. I don't see any reason not to use kexec() inside a VM - it has the potential to provide automated recovery from a failure of the VMs kernel with the opportunity for saving a crashdump of the failure. A panic() with a reboot timeout won't do that, and reading the libvirt documentation, setting on_reboot to "preserve" won't either (the documentation states "The preserve action for an on_reboot event is treated as a destroy".) Surely it has to be a good thing to avoiding having CPUs spinning inside a VM that is doing no useful work. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: 8830/1: NOMMU: Toggle only bits in EXC_RETURN we are really care ofVladimir Murzin2019-04-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 72cd4064fccaae15ab84d40d4be23667402df4ed ] ARMv8M introduces support for Security extension to M class, among other things it affects exception handling, especially, encoding of EXC_RETURN. The new bits have been added: Bit [6] Secure or Non-secure stack Bit [5] Default callee register stacking Bit [0] Exception Secure which conflicts with hard-coded value of EXC_RETURN: In fact, we only care of few bits: Bit [3] Mode (0 - Handler, 1 - Thread) Bit [2] Stack pointer selection (0 - Main, 1 - Process) We can toggle only those bits and left other bits as they were on exception entry. It is basically, what patch does - saves EXC_RETURN when we do transition form Thread to Handler mode (it is first svc), so later saved value is used instead of EXC_RET_THREADMODE_PROCESSSTACK. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: 8824/1: fix a migrating irq bug when hotplug cpuDietmar Eggemann2019-03-231-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 1b5ba350784242eb1f899bcffd95d2c7cff61e84 ] Arm TC2 fails cpu hotplug stress test. This issue was tracked down to a missing copy of the new affinity cpumask for the vexpress-spc interrupt into struct irq_common_data.affinity when the interrupt is migrated in migrate_one_irq(). Fix it by replacing the arm specific hotplug cpu migration with the generic irq code. This is the counterpart implementation to commit 217d453d473c ("arm64: fix a migrating irq bug when hotplug cpu"). Tested with cpu hotplug stress test on Arm TC2 (multi_v7_defconfig plus CONFIG_ARM_BIG_LITTLE_CPUFREQ=y and CONFIG_ARM_VEXPRESS_SPC_CPUFREQ=y). The vexpress-spc interrupt (irq=22) on this board is affine to CPU0. Its affinity cpumask now changes correctly e.g. from 0 to 1-4 when CPU0 is hotplugged out. Suggested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: spectre-v2: per-CPU vtables to work around big.Little systemsRussell King2019-02-201-0/+23
| | | | | | | | | | | | | | | | | | | | | | Commit 383fb3ee8024d596f488d2dbaf45e572897acbdb upstream. In big.Little systems, some CPUs require the Spectre workarounds in paths such as the context switch, but other CPUs do not. In order to handle these differences, we need per-CPU vtables. We are unable to use the kernel's per-CPU variables to support this as per-CPU is not initialised at times when we need access to the vtables, so we have to use an array indexed by logical CPU number. We use an array-of-pointers to avoid having function pointers in the kernel's read/write .data section. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: add PROC_VTABLE and PROC_TABLE macrosRussell King2019-02-201-13/+26
| | | | | | | | | | | | | | | | | | | | Commit e209950fdd065d2cc46e6338e47e52841b830cba upstream. Allow the way we access members of the processor vtable to be changed at compile time. We will need to move to per-CPU vtables to fix the Spectre variant 2 issues on big.Little systems. However, we have a couple of calls that do not need the vtable treatment, and indeed cause a kernel warning due to the (later) use of smp_processor_id(), so also introduce the PROC_TABLE macro for these which always use CPU 0's function pointers. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: clean up per-processor check_bugs method callRussell King2019-02-201-0/+1
| | | | | | | | | | | | | | | Commit 945aceb1db8885d3a35790cf2e810f681db52756 upstream. Call the per-processor type check_bugs() method in the same way as we do other per-processor functions - move the "processor." detail into proc-fns.h. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: split out processor lookupRussell King2019-02-201-0/+1
| | | | | | | | | | | | | | | Commit 65987a8553061515b5851b472081aedb9837a391 upstream. Split out the lookup of the processor type and associated error handling from the rest of setup_processor() - we will need to use this in the secondary CPU bringup path for big.Little Spectre variant 2 mitigation. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: 8796/1: spectre-v1,v1.1: provide helpers for address sanitizationJulien Thierry2019-02-202-0/+37
| | | | | | | | | | | | | | | Commit afaf6838f4bc896a711180b702b388b8cfa638fc upstream. Introduce C and asm helpers to sanitize user address, taking the address range they target into account. Use asm helper for existing sanitization in __copy_from_user(). Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: 8795/1: spectre-v1.1: use put_user() for __put_user()Julien Thierry2019-02-201-6/+9
| | | | | | | | | | | | | | Commit e3aa6243434fd9a82e84bb79ab1abd14f2d9a5a7 upstream. When Spectre mitigation is required, __put_user() needs to include check_uaccess. This is already the case for put_user(), so just make __put_user() an alias of put_user(). Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: 8794/1: uaccess: Prevent speculative use of the current addr_limitJulien Thierry2019-02-201-0/+8
| | | | | | | | | | | | | | | | | | | | | Commit 621afc677465db231662ed126ae1f355bf8eac47 upstream. A mispredicted conditional call to set_fs could result in the wrong addr_limit being forwarded under speculation to a subsequent access_ok check, potentially forming part of a spectre-v1 attack using uaccess routines. This patch prevents this forwarding from taking place, but putting heavy barriers in set_fs after writing the addr_limit. Porting commit c2f0ad4fc089cff8 ("arm64: uaccess: Prevent speculative use of the current addr_limit"). Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: 8791/1: vfp: use __copy_to_user() when saving VFP stateJulien Thierry2019-02-201-2/+2
| | | | | | | | | | | | | | | Commit 3aa2df6ec2ca6bc143a65351cca4266d03a8bc41 upstream. 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> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: spectre-v1: mitigate user accessesRussell King2018-10-181-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* ARM: spectre-v1: use get_user() for __get_user()Russell King2018-10-181-6/+11
| | | | | | | | | | | | | | | | | | 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>
* ARM: use __inttype() in get_user()Russell King2018-10-181-1/+8
| | | | | | | | | | | | | | | | 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>
* ARM: vfp: use __copy_from_user() when restoring VFP stateRussell King2018-10-181-2/+2
| | | | | | | | | | | | | | | | | | | | | 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>
* ARM: spectre-v1: add array_index_mask_nospec() implementationRussell King2018-10-181-0/+19
| | | | | | | | | | | | | | 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>
* ARM: spectre-v1: add speculation barrier (csdb) macrosRussell King2018-10-182-0/+21
| | | | | | | | | | | | | 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>
* ARM: KVM: report support for SMCCC_ARCH_WORKAROUND_1Russell King2018-10-181-2/+12
| | | | | | | | | | | | | | 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>
* ARM: spectre-v2: KVM: invalidate icache on guest exit for Brahma B15Russell King2018-10-181-0/+1
| | | | | | | | | | | | | | 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>
* ARM: KVM: invalidate icache on guest exit for Cortex-A15Marc Zyngier2018-10-181-0/+5
| | | | | | | | | | | | | | | | | 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>
* ARM: KVM: invalidate BTB on guest exit for Cortex-A12/A17Marc Zyngier2018-10-182-3/+16
| | | | | | | | | | | | | | | | | | | 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>
* ARM: spectre-v2: harden user aborts in kernel spaceRussell King2018-10-182-0/+18
| | | | | | | | | | | | | | | | | | | | | 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>
* ARM: bugs: add support for per-processor bug checkingRussell King2018-10-181-0/+4
| | | | | | | | | | | | | | | | | | | | | 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>
* ARM: bugs: hook processor bug checking into SMP and suspend pathsRussell King2018-10-181-0/+2
| | | | | | | | | | | | | | | | | 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>
* ARM: bugs: prepare processor bug infrastructureRussell King2018-10-181-2/+2
| | | | | | | | | | | | | | | 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>
* ARM: add more CPU part numbers for Cortex and Brahma B15 CPUsRussell King2018-10-181-0/+8
| | | | | | | | | | | | | | | 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>
* arm64: KVM: Add ARCH_WORKAROUND_2 discovery through ARCH_FEATURES_FUNC_IDMarc Zyngier2018-07-221-0/+12
| | | | | | | | | | | | | | | commit 5d81f7dc9bca4f4963092433e27b508cbe524a32 upstream. Now that all our infrastructure is in place, let's expose the availability of ARCH_WORKAROUND_2 to guests. We take this opportunity to tidy up a couple of SMCCC constants. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* arm64: KVM: Add ARCH_WORKAROUND_2 support for guestsMarc Zyngier2018-07-221-0/+5
| | | | | | | | | | | | | | | | | | | commit 55e3748e8902ff641e334226bdcb432f9a5d78d3 upstream. In order to offer ARCH_WORKAROUND_2 support to guests, we need a bit of infrastructure. Let's add a flag indicating whether or not the guest uses SSBD mitigation. Depending on the state of this flag, allow KVM to disable ARCH_WORKAROUND_2 before entering the guest, and enable it when exiting it. Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: arm/arm64: Do not use kern_hyp_va() with kvm_vgic_global_stateMarc Zyngier2018-07-221-0/+7
| | | | | | | | | | | | | | | | | | | Commit 44a497abd621a71c645f06d3d545ae2f46448830 upstream. kvm_vgic_global_state is part of the read-only section, and is usually accessed using a PC-relative address generation (adrp + add). It is thus useless to use kern_hyp_va() on it, and actively problematic if kern_hyp_va() becomes non-idempotent. On the other hand, there is no way that the compiler is going to guarantee that such access is always PC relative. So let's bite the bullet and provide our own accessor. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ARM: 8764/1: kgdb: fix NUMREGBYTES so that gdb_regs[] is the correct sizeDavid Rivshin2018-07-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | commit 76ed0b803a2ab793a1b27d1dfe0de7955282cd34 upstream. NUMREGBYTES (which is used as the size for gdb_regs[]) is incorrectly based on DBG_MAX_REG_NUM instead of GDB_MAX_REGS. DBG_MAX_REG_NUM is the number of total registers, while GDB_MAX_REGS is the number of 'unsigned longs' it takes to serialize those registers. Since FP registers require 3 'unsigned longs' each, DBG_MAX_REG_NUM is smaller than GDB_MAX_REGS. This causes GDB 8.0 give the following error on connect: "Truncated register 19 in remote 'g' packet" This also causes the register serialization/deserialization logic to overflow gdb_regs[], overwriting whatever follows. Fixes: 834b2964b7ab ("kgdb,arm: fix register dump") Cc: <stable@vger.kernel.org> # 2.6.37+ Signed-off-by: David Rivshin <drivshin@allworx.com> Acked-by: Rabin Vincent <rabin@rab.in> Tested-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ARM: 8748/1: mm: Define vdso_start, vdso_end as arrayJinbum Park2018-05-301-2/+0
| | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 73b9160d0dfe44dfdaffd6465dc1224c38a4a73c ] Define vdso_start, vdso_end as array to avoid compile-time analysis error for the case of built with CONFIG_FORTIFY_SOURCE. and, since vdso_start, vdso_end are used in vdso.c only, move extern-declaration from vdso.h to vdso.c. If kernel is built with CONFIG_FORTIFY_SOURCE, compile-time error happens at this code. - if (memcmp(&vdso_start, "177ELF", 4)) The size of "&vdso_start" is recognized as 1 byte, but n is 4, So that compile-time error is reported. Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jinbum Park <jinb.park7@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ARM: 8772/1: kprobes: Prohibit kprobes on get_user functionsMasami Hiramatsu2018-05-221-0/+10
| | | | | | | | | | | | | | | | | commit 0d73c3f8e7f6ee2aab1bb350f60c180f5ae21a2c upstream. Since do_undefinstr() uses get_user to get the undefined instruction, it can be called before kprobes processes recursive check. This can cause an infinit recursive exception. Prohibit probing on get_user functions. Fixes: 24ba613c9d6c ("ARM kprobes: core code") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lockAndre Przywara2018-05-221-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | commit bf308242ab98b5d1648c3663e753556bef9bec01 upstream. kvm_read_guest() will eventually look up in kvm_memslots(), which requires either to hold the kvm->slots_lock or to be inside a kvm->srcu critical section. In contrast to x86 and s390 we don't take the SRCU lock on every guest exit, so we have to do it individually for each kvm_read_guest() call. Provide a wrapper which does that and use that everywhere. Note that ending the SRCU critical section before returning from the kvm_read_guest() wrapper is safe, because the data has been *copied*, so we don't need to rely on valid references to the memslot anymore. Cc: Stable <stable@vger.kernel.org> # 4.8+ Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* arm/arm64: KVM: Add PSCI version selection APIMarc Zyngier2018-05-012-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | commit 85bd0ba1ff9875798fad94218b627ea9f768f3c3 upstream. Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1 or 1.0 to a guest, defaulting to the latest version of the PSCI implementation that is compatible with the requested version. This is no different from doing a firmware upgrade on KVM. But in order to give a chance to hypothetical badly implemented guests that would have a fit by discovering something other than PSCI 0.2, let's provide a new API that allows userspace to pick one particular version of the API. This is implemented as a new class of "firmware" registers, where we expose the PSCI version. This allows the PSCI version to be save/restored as part of a guest migration, and also set to any supported version if the guest requires it. Cc: stable@vger.kernel.org #4.16 Reviewed-by: Christoffer Dall <cdall@kernel.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACKLevin, Alexander (Sasha Levin)2018-02-221-1/+1
| | | | | | | | | | | | | | | | | | | | commit 75f296d93bcebcfe375884ddac79e30263a31766 upstream. Convert all allocations that used a NOTRACK flag to stop using it. Link: http://lkml.kernel.org/r/20171007030159.22241-3-alexander.levin@verizon.com Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Cc: Alexander Potapenko <glider@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tim Hansen <devtimhansen@gmail.com> Cc: Vegard Nossum <vegardno@ifi.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kmemcheck: remove annotationsLevin, Alexander (Sasha Levin)2018-02-221-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 4950276672fce5c241857540f8561c440663673d upstream. Patch series "kmemcheck: kill kmemcheck", v2. As discussed at LSF/MM, kill kmemcheck. KASan is a replacement that is able to work without the limitation of kmemcheck (single CPU, slow). KASan is already upstream. We are also not aware of any users of kmemcheck (or users who don't consider KASan as a suitable replacement). The only objection was that since KASAN wasn't supported by all GCC versions provided by distros at that time we should hold off for 2 years, and try again. Now that 2 years have passed, and all distros provide gcc that supports KASAN, kill kmemcheck again for the very same reasons. This patch (of 4): Remove kmemcheck annotations, and calls to kmemcheck from the kernel. [alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs] Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.com Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Cc: Alexander Potapenko <glider@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tim Hansen <devtimhansen@gmail.com> Cc: Vegard Nossum <vegardno@ifi.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening supportMarc Zyngier2018-02-161-0/+6
| | | | | | | | | | | | | | | | | | | | Commit 6167ec5c9145 upstream. A new feature of SMCCC 1.1 is that it offers firmware-based CPU workarounds. In particular, SMCCC_ARCH_WORKAROUND_1 provides BP hardening for CVE-2017-5715. If the host has some mitigation for this issue, report that we deal with it using SMCCC_ARCH_WORKAROUND_1, as we apply the host workaround on every guest exit. Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* arm/arm64: KVM: Consolidate the PSCI include filesMarc Zyngier2018-02-161-27/+0
| | | | | | | | | | | | | | | | Commit 1a2fb94e6a77 upstream. As we're about to update the PSCI support, and because I'm lazy, let's move the PSCI include file to include/kvm so that both ARM architectures can find it. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* arm64: KVM: Use per-CPU vector when BP hardening is enabledMarc Zyngier2018-02-161-0/+10
| | | | | | | | | | | | Commit 6840bdd73d07 upstream. Now that we have per-CPU vectors, let's plug then in the KVM/arm64 code. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* linux/compiler.h: Split into compiler.h and compiler_types.hWill Deacon2017-12-251-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d15155824c5014803d91b829736d249c500bdda6 upstream. linux/compiler.h is included indirectly by linux/types.h via uapi/linux/types.h -> uapi/linux/posix_types.h -> linux/stddef.h -> uapi/linux/stddef.h and is needed to provide a proper definition of offsetof. Unfortunately, compiler.h requires a definition of smp_read_barrier_depends() for defining lockless_dereference() and soon for defining READ_ONCE(), which means that all users of READ_ONCE() will need to include asm/barrier.h to avoid splats such as: In file included from include/uapi/linux/stddef.h:1:0, from include/linux/stddef.h:4, from arch/h8300/kernel/asm-offsets.c:11: include/linux/list.h: In function 'list_empty': >> include/linux/compiler.h:343:2: error: implicit declaration of function 'smp_read_barrier_depends' [-Werror=implicit-function-declaration] smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \ ^ A better alternative is to include asm/barrier.h in linux/compiler.h, but this requires a type definition for "bool" on some architectures (e.g. x86), which is defined later by linux/types.h. Type "bool" is also used directly in linux/compiler.h, so the whole thing is pretty fragile. This patch splits compiler.h in two: compiler_types.h contains type annotations, definitions and the compiler-specific parts, whereas compiler.h #includes compiler-types.h and additionally defines macros such as {READ,WRITE.ACCESS}_ONCE(). uapi/linux/stddef.h and linux/linkage.h are then moved over to include linux/compiler_types.h, which fixes the build for h8 and blackfin. Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1508840570-22169-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ARM: BUG if jumping to usermode address in kernel modeRussell King2017-12-141-0/+18
| | | | | | | | | | | | | | | | commit 8bafae202c82dc257f649ea3c275a0f35ee15113 upstream. Detect if we are returning to usermode via the normal kernel exit paths but the saved PSR value indicates that we are in kernel mode. This could occur due to corrupted stack state, which has been observed with "ftracetest". This ensures that we catch the problem case before we get to user code. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Cc: Alex Shi <alex.shi@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-oneMarc Zyngier2017-12-141-2/+1
| | | | | | | | | | | | | | | | | | | | commit 5553b142be11e794ebc0805950b2e8313f93d718 upstream. VTTBR_BADDR_MASK is used to sanity check the size and alignment of the VTTBR address. It seems to currently be off by one, thereby only allowing up to 39-bit addresses (instead of 40-bit) and also insufficiently checking the alignment. This patch fixes it. This patch is the 32bit pendent of Kristina's arm64 fix, and she deserves the actual kudos for pinpointing that one. Fixes: f7ed45be3ba52 ("KVM: ARM: World-switch implementation") Reported-by: Kristina Martsenko <kristina.martsenko@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds2017-11-042-1/+27
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull ARM fixes from Russell King: - omit EFI memory map sorting, which was recently introduced, but caused problems with the decompressor due to additional sections being emitted. - avoid unaligned load fault-generating instructions in the decompressor by switching to a private unaligned implementation. - add a symbol into the decompressor to further debug non-boot situations (ld's documentation is extremely poor for how "." works, ld doesn't seem to follow its own documentation!) - parse endian information to sparse * 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: add debug ".edata_real" symbol ARM: 8716/1: pass endianness info to sparse efi/libstub: arm: omit sorting of the UEFI memory map ARM: 8715/1: add a private asm/unaligned.h
| * ARM: 8715/1: add a private asm/unaligned.hArnd Bergmann2017-10-242-1/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The asm-generic/unaligned.h header provides two different implementations for accessing unaligned variables: the access_ok.h version used when CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is set pretends that all pointers are in fact aligned, while the le_struct.h version convinces gcc that the alignment of a pointer is '1', to make it issue the correct load/store instructions depending on the architecture flags. On ARMv5 and older, we always use the second version, to let the compiler use byte accesses. On ARMv6 and newer, we currently use the access_ok.h version, so the compiler can use any instruction including stm/ldm and ldrd/strd that will cause an alignment trap. This trap can significantly impact performance when we have to do a lot of fixups and, worse, has led to crashes in the LZ4 decompressor code that does not have a trap handler. This adds an ARM specific version of asm/unaligned.h that uses the le_struct.h/be_struct.h implementation unconditionally. This should lead to essentially the same code on ARMv6+ as before, with the exception of using regular load/store instructions instead of the trapping instructions multi-register variants. The crash in the LZ4 decompressor code was probably introduced by the patch replacing the LZ4 implementation, commit 4e1a33b105dd ("lib: update LZ4 compressor module"), so linux-4.11 and higher would be affected most. However, we probably want to have this backported to all older stable kernels as well, to help with the performance issues. There are two follow-ups that I think we should also work on, but not backport to stable kernels, first to change the asm-generic version of the header to remove the ARM special case, and second to review all other uses of CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to see if they might be affected by the same problem on ARM. Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
* | License cleanup: add SPDX license identifier to uapi header files with a licenseGreg Kroah-Hartman2017-11-025-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many user space API headers have licensing information, which is either incomplete, badly formatted or just a shorthand for referring to the license under which the file is supposed to be. This makes it hard for compliance tools to determine the correct license. Update these files with an SPDX license identifier. The identifier was chosen based on the license information in the file. GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license identifier with the added 'WITH Linux-syscall-note' exception, which is the officially assigned exception identifier for the kernel syscall exception: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". This exception makes it possible to include GPL headers into non GPL code, without confusing license compliance tools. Headers which have either explicit dual licensing or are just licensed under a non GPL license are updated with the corresponding SPDX identifier and the GPLv2 with syscall exception identifier. The format is: ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE) SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. The update does not remove existing license information as this has to be done on a case by case basis and the copyright holders might have to be consulted. This will happen in a separate step. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | License cleanup: add SPDX license identifier to uapi header files with no ↵Greg Kroah-Hartman2017-11-0213-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | license Many user space API headers are missing licensing information, which makes it hard for compliance tools to determine the correct license. By default are files without license information under the default license of the kernel, which is GPLV2. Marking them GPLV2 would exclude them from being included in non GPLV2 code, which is obviously not intended. The user space API headers fall under the syscall exception which is in the kernels COPYING file: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". otherwise syscall usage would not be possible. Update the files which contain no license information with an SPDX license identifier. The chosen identifier is 'GPL-2.0 WITH Linux-syscall-note' which is the officially assigned identifier for the Linux syscall exception. SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-0295-0/+95
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Revert "arm/syscalls: Check address limit on user-mode return"Thomas Garnier2017-09-172-11/+6
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 73ac5d6a2b6ac3ae8d1e1818f3e9946f97489bc9. The work pending loop can call set_fs after addr_limit_user_check removed the _TIF_FSCHECK flag. This may happen at anytime based on how ARM handles alignment exceptions. It leads to an infinite loop condition. After discussion, it has been agreed that the generic approach is not tailored to the ARM architecture and any fix might not be complete. This patch will be replaced by an architecture specific implementation. The work flag approach will be kept for other architectures. Reported-by: Leonard Crestez <leonard.crestez@nxp.com> Signed-off-by: Thomas Garnier <thgarnie@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Pratyush Anand <panand@redhat.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: Will Drewry <wad@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: David Howells <dhowells@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-api@vger.kernel.org Cc: Yonghong Song <yhs@fb.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1504798247-48833-3-git-send-email-keescook@chromium.org
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-02 06:38:42 +0000