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2018-02-04Merge tag 'usercopy-v4.16-rc1' of ↵Linus Torvalds1-0/+10
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardened usercopy whitelisting from Kees Cook: "Currently, hardened usercopy performs dynamic bounds checking on slab cache objects. This is good, but still leaves a lot of kernel memory available to be copied to/from userspace in the face of bugs. To further restrict what memory is available for copying, this creates a way to whitelist specific areas of a given slab cache object for copying to/from userspace, allowing much finer granularity of access control. Slab caches that are never exposed to userspace can declare no whitelist for their objects, thereby keeping them unavailable to userspace via dynamic copy operations. (Note, an implicit form of whitelisting is the use of constant sizes in usercopy operations and get_user()/put_user(); these bypass all hardened usercopy checks since these sizes cannot change at runtime.) This new check is WARN-by-default, so any mistakes can be found over the next several releases without breaking anyone's system. The series has roughly the following sections: - remove %p and improve reporting with offset - prepare infrastructure and whitelist kmalloc - update VFS subsystem with whitelists - update SCSI subsystem with whitelists - update network subsystem with whitelists - update process memory with whitelists - update per-architecture thread_struct with whitelists - update KVM with whitelists and fix ioctl bug - mark all other allocations as not whitelisted - update lkdtm for more sensible test overage" * tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (38 commits) lkdtm: Update usercopy tests for whitelisting usercopy: Restrict non-usercopy caches to size 0 kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl kvm: whitelist struct kvm_vcpu_arch arm: Implement thread_struct whitelist for hardened usercopy arm64: Implement thread_struct whitelist for hardened usercopy x86: Implement thread_struct whitelist for hardened usercopy fork: Provide usercopy whitelisting for task_struct fork: Define usercopy region in thread_stack slab caches fork: Define usercopy region in mm_struct slab caches net: Restrict unwhitelisted proto caches to size 0 sctp: Copy struct sctp_sock.autoclose to userspace using put_user() sctp: Define usercopy region in SCTP proto slab cache caif: Define usercopy region in caif proto slab cache ip: Define usercopy region in IP proto slab cache net: Define usercopy region in struct proto slab cache scsi: Define usercopy region in scsi_sense_cache slab cache cifs: Define usercopy region in cifs_request slab cache vxfs: Define usercopy region in vxfs_inode slab cache ufs: Define usercopy region in ufs_inode_cache slab cache ...
2018-02-02Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds10-133/+84
Pull ARM updates from Russell King: - StrongARM SA1111 updates to modernise and remove cruft - Add StrongARM gpio drivers for board GPIOs - Verify size of zImage is what we expect to avoid issues with appended DTB - nommu updates from Vladimir Murzin - page table read-write-execute checking from Jinbum Park - Broadcom Brahma-B15 cache updates from Florian Fainelli - Avoid failure with kprobes test caused by inappropriately placed kprobes - Remove __memzero optimisation (which was incorrectly being used directly by some drivers) * 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (32 commits) ARM: 8745/1: get rid of __memzero() ARM: 8744/1: don't discard memblock for kexec ARM: 8743/1: bL_switcher: add MODULE_LICENSE tag ARM: 8742/1: Always use REFCOUNT_FULL ARM: 8741/1: B15: fix unused label warnings ARM: 8740/1: NOMMU: Make sure we do not hold stale data in mem[] array ARM: 8739/1: NOMMU: Setup VBAR/Hivecs for secondaries cores ARM: 8738/1: Disable CONFIG_DEBUG_VIRTUAL for NOMMU ARM: 8737/1: mm: dump: add checking for writable and executable ARM: 8736/1: mm: dump: make the page table dumping seq_file ARM: 8735/1: mm: dump: make page table dumping reusable ARM: sa1100/neponset: add GPIO drivers for control and modem registers ARM: sa1100/assabet: add BCR/BSR GPIO driver ARM: 8734/1: mm: idmap: Mark variables as ro_after_init ARM: 8733/1: hw_breakpoint: Mark variables as __ro_after_init ARM: 8732/1: NOMMU: Allow userspace to access background MPU region ARM: 8727/1: MAINTAINERS: Update brcmstb entries to cover B15 code ARM: 8728/1: B15: Register reboot notifier for KEXEC ARM: 8730/1: B15: Add suspend/resume hooks ARM: 8726/1: B15: Add CPU hotplug awareness ...
2018-02-02Merge tag 'clk-for-linus' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux Pull clk updates from Stephen Boyd: "The core framework has a handful of patches this time around, mostly due to the clk rate protection support added by Jerome Brunet. This feature will allow consumers to lock in a certain rate on the output of a clk so that things like audio playback don't hear pops when the clk frequency changes due to shared parent clks changing rates. Currently the clk API doesn't guarantee the rate of a clk stays at the rate you request after clk_set_rate() is called, so this new API will allow drivers to express that requirement. Beyond this, the core got some debugfs pretty printing patches and a couple minor non-critical fixes. Looking outside of the core framework diff we have some new driver additions and the removal of a legacy TI clk driver. Both of these hit high in the dirstat. Also, the removal of the asm-generic/clkdev.h file causes small one-liners in all the architecture Kbuild files. Overall, the driver diff seems to be the normal stuff that comes all the time to fix little problems here and there and to support new hardware. Summary: Core: - Clk rate protection - Symbolic clk flags in debugfs output - Clk registration enabled clks while doing bookkeeping updates New Drivers: - Spreadtrum SC9860 - HiSilicon hi3660 stub - Qualcomm A53 PLL, SPMI clkdiv, and MSM8916 APCS - Amlogic Meson-AXG - ASPEED BMC Removed Drivers: - TI OMAP 3xxx legacy clk (non-DT) support - asm*/clkdev.h got removed (not really a driver) Updates: - Renesas FDP1-0 module clock on R-Car M3-W - Renesas LVDS module clock on R-Car V3M - Misc fixes to pr_err() prints - Qualcomm MSM8916 audio fixes - Qualcomm IPQ8074 rounded out support for more peripherals - Qualcomm Alpha PLL variants - Divider code was using container_of() on bad pointers - Allwinner DE2 clks on H3 - Amlogic minor data fixes and dropping of CLK_IGNORE_UNUSED - Mediatek clk driver compile test support - AT91 PMC clk suspend/resume restoration support - PLL issues fixed on si5351 - Broadcom IProc PLL calculation updates - DVFS support for Armada mvebu CPU clks - Allwinner fixed post-divider support - TI clkctrl fixes and support for newer SoCs" * tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (125 commits) clk: aspeed: Handle inverse polarity of USB port 1 clock gate clk: aspeed: Fix return value check in aspeed_cc_init() clk: aspeed: Add reset controller clk: aspeed: Register gated clocks clk: aspeed: Add platform driver and register PLLs clk: aspeed: Register core clocks clk: Add clock driver for ASPEED BMC SoCs clk: mediatek: adjust dependency of reset.c to avoid unexpectedly being built clk: fix reentrancy of clk_enable() on UP systems clk: meson-axg: fix potential NULL dereference in axg_clkc_probe() clk: Simplify debugfs registration clk: Fix debugfs_create_*() usage clk: Show symbolic clock flags in debugfs clk: renesas: r8a7796: Add FDP clock clk: Move __clk_{get,put}() into private clk.h API clk: sunxi: Use CLK_IS_CRITICAL flag for critical clks clk: Improve flags doc for of_clk_detect_critical() arch: Remove clkdev.h asm-generic from Kbuild clk: sunxi-ng: a83t: Add M divider to TCON1 clock clk: Prepare to remove asm-generic/clkdev.h ...
2018-02-01Merge branch 'x86/hyperv' of ↵Radim Krčmář1-3/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Topic branch for stable KVM clockource under Hyper-V. Thanks to Christoffer Dall for resolving the ARM conflict.
2018-02-01arm/mm: provide pmdp_establish() helperKirill A. Shutemov1-0/+3
ARM LPAE doesn't have hardware dirty/accessed bits. generic_pmdp_establish() is the right implementation of pmdp_establish for this case. Link: http://lkml.kernel.org/r/20171213105756.69879-4-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31Merge tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds2-34/+37
Pull dma mapping updates from Christoph Hellwig: "Except for a runtime warning fix from Christian this is all about consolidation of the generic no-IOMMU code, a well as the glue code for swiotlb. All the code is based on the x86 implementation with hooks to allow all architectures that aren't cache coherent to use it. The x86 conversion itself has been deferred because the x86 maintainers were a little busy in the last months" * tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mapping: (57 commits) MAINTAINERS: add the iommu list for swiotlb and xen-swiotlb arm64: use swiotlb_alloc and swiotlb_free arm64: replace ZONE_DMA with ZONE_DMA32 mips: use swiotlb_{alloc,free} mips/netlogic: remove swiotlb support tile: use generic swiotlb_ops tile: replace ZONE_DMA with ZONE_DMA32 unicore32: use generic swiotlb_ops ia64: remove an ifdef around the content of pci-dma.c ia64: clean up swiotlb support ia64: use generic swiotlb_ops ia64: replace ZONE_DMA with ZONE_DMA32 swiotlb: remove various exports swiotlb: refactor coherent buffer allocation swiotlb: refactor coherent buffer freeing swiotlb: wire up ->dma_supported in swiotlb_dma_ops swiotlb: add common swiotlb_map_ops swiotlb: rename swiotlb_free to swiotlb_exit x86: rename swiotlb_dma_ops powerpc: rename swiotlb_dma_ops ...
2018-01-31Merge branch 'siginfo-linus' of ↵Linus Torvalds1-0/+13
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull siginfo cleanups from Eric Biederman: "Long ago when 2.4 was just a testing release copy_siginfo_to_user was made to copy individual fields to userspace, possibly for efficiency and to ensure initialized values were not copied to userspace. Unfortunately the design was complex, it's assumptions unstated, and humans are fallible and so while it worked much of the time that design failed to ensure unitialized memory is not copied to userspace. This set of changes is part of a new design to clean up siginfo and simplify things, and hopefully make the siginfo handling robust enough that a simple inspection of the code can be made to ensure we don't copy any unitializied fields to userspace. The design is to unify struct siginfo and struct compat_siginfo into a single definition that is shared between all architectures so that anyone adding to the set of information shared with struct siginfo can see the whole picture. Hopefully ensuring all future si_code assignments are arch independent. The design is to unify copy_siginfo_to_user32 and copy_siginfo_from_user32 so that those function are complete and cope with all of the different cases documented in signinfo_layout. I don't think there was a single implementation of either of those functions that was complete and correct before my changes unified them. The design is to introduce a series of helpers including force_siginfo_fault that take the values that are needed in struct siginfo and build the siginfo structure for their callers. Ensuring struct siginfo is built correctly. The remaining work for 4.17 (unless someone thinks it is post -rc1 material) is to push usage of those helpers down into the architectures so that architecture specific code will not need to deal with the fiddly work of intializing struct siginfo, and then when struct siginfo is guaranteed to be fully initialized change copy siginfo_to_user into a simple wrapper around copy_to_user. Further there is work in progress on the issues that have been documented requires arch specific knowledge to sort out. The changes below fix or at least document all of the issues that have been found with siginfo generation. Then proceed to unify struct siginfo the 32 bit helpers that copy siginfo to and from userspace, and generally clean up anything that is not arch specific with regards to siginfo generation. It is a lot but with the unification you can of siginfo you can already see the code reduction in the kernel" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (45 commits) signal/memory-failure: Use force_sig_mceerr and send_sig_mceerr mm/memory_failure: Remove unused trapno from memory_failure signal/ptrace: Add force_sig_ptrace_errno_trap and use it where needed signal/powerpc: Remove unnecessary signal_code parameter of do_send_trap signal: Helpers for faults with specialized siginfo layouts signal: Add send_sig_fault and force_sig_fault signal: Replace memset(info,...) with clear_siginfo for clarity signal: Don't use structure initializers for struct siginfo signal/arm64: Better isolate the COMPAT_TASK portion of ptrace_hbptriggered ptrace: Use copy_siginfo in setsiginfo and getsiginfo signal: Unify and correct copy_siginfo_to_user32 signal: Remove the code to clear siginfo before calling copy_siginfo_from_user32 signal: Unify and correct copy_siginfo_from_user32 signal/blackfin: Remove pointless UID16_SIGINFO_COMPAT_NEEDED signal/blackfin: Move the blackfin specific si_codes to asm-generic/siginfo.h signal/tile: Move the tile specific si_codes to asm-generic/siginfo.h signal/frv: Move the frv specific si_codes to asm-generic/siginfo.h signal/ia64: Move the ia64 specific si_codes to asm-generic/siginfo.h signal/powerpc: Remove redefinition of NSIGTRAP on powerpc signal: Move addr_lsb into the _sigfault union for clarity ...
2018-01-31Merge tag 'arm64-upstream' of ↵Linus Torvalds2-0/+22
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "The main theme of this pull request is security covering variants 2 and 3 for arm64. I expect to send additional patches next week covering an improved firmware interface (requires firmware changes) for variant 2 and way for KPTI to be disabled on unaffected CPUs (Cavium's ThunderX doesn't work properly with KPTI enabled because of a hardware erratum). Summary: - Security mitigations: - variant 2: invalidate the branch predictor with a call to secure firmware - variant 3: implement KPTI for arm64 - 52-bit physical address support for arm64 (ARMv8.2) - arm64 support for RAS (firmware first only) and SDEI (software delegated exception interface; allows firmware to inject a RAS error into the OS) - perf support for the ARM DynamIQ Shared Unit PMU - CPUID and HWCAP bits updated for new floating point multiplication instructions in ARMv8.4 - remove some virtual memory layout printks during boot - fix initial page table creation to cope with larger than 32M kernel images when 16K pages are enabled" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (104 commits) arm64: Fix TTBR + PAN + 52-bit PA logic in cpu_do_switch_mm arm64: Turn on KPTI only on CPUs that need it arm64: Branch predictor hardening for Cavium ThunderX2 arm64: Run enable method for errata work arounds on late CPUs arm64: Move BP hardening to check_and_switch_context arm64: mm: ignore memory above supported physical address size arm64: kpti: Fix the interaction between ASID switching and software PAN KVM: arm64: Emulate RAS error registers and set HCR_EL2's TERR & TEA KVM: arm64: Handle RAS SErrors from EL2 on guest exit KVM: arm64: Handle RAS SErrors from EL1 on guest exit KVM: arm64: Save ESR_EL2 on guest SError KVM: arm64: Save/Restore guest DISR_EL1 KVM: arm64: Set an impdef ESR for Virtual-SError using VSESR_EL2. KVM: arm/arm64: mask/unmask daif around VHE guests arm64: kernel: Prepare for a DISR user arm64: Unconditionally enable IESB on exception entry/return for firmware-first arm64: kernel: Survive corrected RAS errors notified by SError arm64: cpufeature: Detect CPU RAS Extentions arm64: sysreg: Move to use definitions for all the SCTLR bits arm64: cpufeature: __this_cpu_has_cap() shouldn't stop early ...
2018-01-23KVM: arm/arm64: Fix trailing semicolonLuis de Bethencourt1-1/+1
The trailing semicolon is an empty statement that does no operation. Removing it since it doesn't do anything. Signed-off-by: Luis de Bethencourt <luisbg@kernel.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2018-01-21Merge branches 'fixes', 'misc', 'sa1111' and 'sa1100-for-next' into for-nextRussell King13-135/+91
2018-01-21ARM: 8745/1: get rid of __memzero()Nicolas Pitre1-14/+0
The __memzero assembly code is almost identical to memset's except for two orr instructions. The runtime performance of __memset(p, n) and memset(p, 0, n) is accordingly almost identical. However, the memset() macro used to guard against a zero length and to call __memzero at compile time when the fill value is a constant zero interferes with compiler optimizations. Arnd found tha the test against a zero length brings up some new warnings with gcc v8: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82103 And successively rremoving the test against a zero length and the call to __memzero optimization produces the following kernel sizes for defconfig with gcc 6: text data bss dec hex filename 12248142 6278960 413588 18940690 1210312 vmlinux.orig 12244474 6278960 413588 18937022 120f4be vmlinux.no_zero_test 12239160 6278960 413588 18931708 120dffc vmlinux.no_memzero So it is probably not worth keeping __memzero around given that the compiler can do a better job at inlining trivial memset(p,0,n) on its own. And the memset code already handles a zero length just fine. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-01-21ARM: 8739/1: NOMMU: Setup VBAR/Hivecs for secondaries coresVladimir Murzin1-0/+1
With switch to dynamic exception base address setting, VBAR/Hivecs set only for boot CPU, but secondaries stay unaware of that. That might lead to weird effects when trying up to bring up secondaries. Fixes: ad475117d201 ("ARM: 8649/2: nommu: remove Hivecs configuration is asm") Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Acked-by: afzal mohammed <afzal.mohd.ma@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-01-21ARM: 8737/1: mm: dump: add checking for writable and executableJinbum Park1-0/+8
Page mappings with full RWX permissions are a security risk. x86, arm64 has an option to walk the page tables and dump any bad pages. (1404d6f13e47 ("arm64: dump: Add checking for writable and exectuable pages")) Add a similar implementation for arm. Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Laura Abbott <labbott@redhat.com> Reviewed-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Jinbum Park <jinb.park7@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-01-21ARM: 8735/1: mm: dump: make page table dumping reusableJinbum Park1-0/+35
This patch refactors the arm page table dumping code, so multiple tables may be registered with the framework. This patch refers below commits of arm64. (4674fdb9f149 ("arm64: mm: dump: make page table dumping reusable")) (4ddb9bf83349 ("arm64: dump: Make ptdump debugfs a separate option")) Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Laura Abbott <labbott@redhat.com> Reviewed-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Jinbum Park <jinb.park7@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-01-16KVM: arm64: Handle RAS SErrors from EL1 on guest exitJames Morse1-0/+3
We expect to have firmware-first handling of RAS SErrors, with errors notified via an APEI method. For systems without firmware-first, add some minimal handling to KVM. There are two ways KVM can take an SError due to a guest, either may be a RAS error: we exit the guest due to an SError routed to EL2 by HCR_EL2.AMO, or we take an SError from EL2 when we unmask PSTATE.A from __guest_exit. For SError that interrupt a guest and are routed to EL2 the existing behaviour is to inject an impdef SError into the guest. Add code to handle RAS SError based on the ESR. For uncontained and uncategorized errors arm64_is_fatal_ras_serror() will panic(), these errors compromise the host too. All other error types are contained: For the fatal errors the vCPU can't make progress, so we inject a virtual SError. We ignore contained errors where we can make progress as if we're lucky, we may not hit them again. If only some of the CPUs support RAS the guest will see the cpufeature sanitised version of the id registers, but we may still take RAS SError on this CPU. Move the SError handling out of handle_exit() into a new handler that runs before we can be preempted. This allows us to use this_cpu_has_cap(), via arm64_is_ras_serror(). Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16KVM: arm/arm64: mask/unmask daif around VHE guestsJames Morse1-0/+2
Non-VHE systems take an exception to EL2 in order to world-switch into the guest. When returning from the guest KVM implicitly restores the DAIF flags when it returns to the kernel at EL1. With VHE none of this exception-level jumping happens, so KVMs world-switch code is exposed to the host kernel's DAIF values, and KVM spills the guest-exit DAIF values back into the host kernel. On entry to a guest we have Debug and SError exceptions unmasked, KVM has switched VBAR but isn't prepared to handle these. On guest exit Debug exceptions are left disabled once we return to the host and will stay this way until we enter user space. Add a helper to mask/unmask DAIF around VHE guests. The unmask can only happen after the hosts VBAR value has been synchronised by the isb in __vhe_hyp_call (via kvm_call_hyp()). Masking could be as late as setting KVMs VBAR value, but is kept here for symmetry. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-15arm: Implement thread_struct whitelist for hardened usercopyKees Cook1-0/+10
While ARM32 carries FPU state in the thread structure that is saved and restored during signal handling, it doesn't need to declare a usercopy whitelist, since existing accessors are all either using a bounce buffer (for which whitelisting isn't checking the slab), are statically sized (which will bypass the hardened usercopy check), or both. Cc: Russell King <linux@armlinux.org.uk> Cc: Ingo Molnar <mingo@kernel.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Kees Cook <keescook@chromium.org>
2018-01-15dma-direct: rename dma_noop to dma_directChristoph Hellwig1-1/+1
The trivial direct mapping implementation already does a virtual to physical translation which isn't strictly a noop, and will soon learn to do non-direct but linear physical to dma translations through the device offset and a few small tricks. Rename it to a better fitting name. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
2018-01-12signal/arm: Document conflicts with SI_USER and SIGFPEEric W. Biederman1-0/+13
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>
2018-01-10dma-mapping: move dma_mark_clean to dma-direct.hChristoph Hellwig1-2/+0
And unlike the other helpers we don't require a <asm/dma-direct.h> as this helper is a special case for ia64 only, and this keeps it as simple as possible. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-01-10dma-mapping: move swiotlb arch helpers to a new headerChristoph Hellwig2-31/+36
phys_to_dma, dma_to_phys and dma_capable are helpers published by architecture code for use of swiotlb and xen-swiotlb only. Drivers are not supposed to use these directly, but use the DMA API instead. Move these to a new asm/dma-direct.h helper, included by a linux/dma-direct.h wrapper that provides the default linear mapping unless the architecture wants to override it. In the MIPS case the existing dma-coherent.h is reused for now as untangling it will take a bit of work. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Robin Murphy <robin.murphy@arm.com>
2018-01-10Construct init thread stack in the linker script rather than by unionDavid Howells1-3/+0
Construct the init thread stack in the linker script rather than doing it by means of a union so that ia64's init_task.c can be got rid of. The following symbols are then made available from INIT_TASK_DATA() linker script macro: init_thread_union init_stack INIT_TASK_DATA() also expands the region to THREAD_SIZE to accommodate the size of the init stack. init_thread_union is given its own section so that it can be placed into the stack space in the right order. I'm assuming that the ia64 ordering is correct and that the task_struct is first and the thread_info second. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com> Tested-by: Will Deacon <will.deacon@arm.com> (arm64) Tested-by: Palmer Dabbelt <palmer@sifive.com> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2018-01-08arm64: KVM: Use per-CPU vector when BP hardening is enabledMarc Zyngier1-0/+10
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>
2018-01-08KVM: arm/arm64: Drop vcpu parameter from guest cache maintenance operartionsMarc Zyngier1-5/+2
The vcpu parameter isn't used for anything, and gets in the way of further cleanups. Let's get rid of it. Acked-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>
2018-01-08KVM: arm/arm64: Preserve Exec permission across R/W permission faultsMarc Zyngier1-0/+10
So far, we loose the Exec property whenever we take permission faults, as we always reconstruct the PTE/PMD from scratch. This can be counter productive as we can end-up with the following fault sequence: X -> RO -> ROX -> RW -> RWX Instead, we can lookup the existing PTE/PMD and clear the XN bit in the new entry if it was already cleared in the old one, leadig to a much nicer fault sequence: X -> ROX -> RWX 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>
2018-01-08KVM: arm/arm64: Limit icache invalidation to prefetch abortsMarc Zyngier2-2/+14
We've so far eagerly invalidated the icache, no matter how the page was faulted in (data or prefetch abort). But we can easily track execution by setting the XN bits in the S2 page tables, get the prefetch abort at HYP and perform the icache invalidation at that time only. As for most VMs, the instruction working set is pretty small compared to the data set, this is likely to save some traffic (specially as the invalidation is broadcast). 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>
2018-01-08arm: KVM: Add optimized PIPT icache flushingMarc Zyngier2-3/+31
Calling __cpuc_coherent_user_range to invalidate the icache on a PIPT icache machine has some pointless overhead, as it starts by cleaning the dcache to the PoU, while we're guaranteed to have already cleaned it to the PoC. As KVM is the only user of such a feature, let's implement some ad-hoc cache flushing in kvm_mmu.h. Should it become useful to other subsystems, it can be moved to a more global location. 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>
2018-01-08KVM: arm/arm64: Split dcache/icache flushingMarc Zyngier1-18/+42
As we're about to introduce opportunistic invalidation of the icache, let's split dcache and icache flushing. Acked-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2018-01-08KVM: arm/arm64: Detangle kvm_mmu.h from kvm_hyp.hMarc Zyngier1-1/+0
kvm_hyp.h has an odd dependency on kvm_mmu.h, which makes the opposite inclusion impossible. Let's start with breaking that useless dependency. Acked-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>
2018-01-03arch: Remove clkdev.h asm-generic from KbuildStephen Boyd1-1/+0
Now that every architecture is using the generic clkdev.h file and we no longer include asm/clkdev.h anywhere in the tree, we can remove it. Cc: Russell King <linux@armlinux.org.uk> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: <linux-arch@vger.kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2018-01-02KVM: arm/arm64: Avoid work when userspace iqchips are not usedChristoffer Dall1-0/+2
We currently check if the VM has a userspace irqchip in several places along the critical path, and if so, we do some work which is only required for having an irqchip in userspace. This is unfortunate, as we could avoid doing any work entirely, if we didn't have to support irqchip in userspace. Realizing the userspace irqchip on ARM is mostly a developer or hobby feature, and is unlikely to be used in servers or other scenarios where performance is a priority, we can use a refcounted static key to only check the irqchip configuration when we have at least one VM that uses an irqchip in userspace. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-12-22arm64: allow ID map to be extended to 52 bitsKristina Martsenko1-0/+5
Currently, when using VA_BITS < 48, if the ID map text happens to be placed in physical memory above VA_BITS, we increase the VA size (up to 48) and create a new table level, in order to map in the ID map text. This is okay because the system always supports 48 bits of VA. This patch extends the code such that if the system supports 52 bits of VA, and the ID map text is placed that high up, then we increase the VA size accordingly, up to 52. One difference from the current implementation is that so far the condition of VA_BITS < 48 has meant that the top level table is always "full", with the maximum number of entries, and an extra table level is always needed. Now, when VA_BITS = 48 (and using 64k pages), the top level table is not full, and we simply need to increase the number of entries in it, instead of creating a new table level. Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [catalin.marinas@arm.com: reduce arguments to __create_hyp_mappings()] [catalin.marinas@arm.com: reworked/renamed __cpu_uses_extended_idmap_level()] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-22arm64: handle 52-bit addresses in TTBRKristina Martsenko1-0/+2
The top 4 bits of a 52-bit physical address are positioned at bits 2..5 in the TTBR registers. Introduce a couple of macros to move the bits there, and change all TTBR writers to use them. Leave TTBR0 PAN code unchanged, to avoid complicating it. A system with 52-bit PA will have PAN anyway (because it's ARMv8.1 or later), and a system without 52-bit PA can only use up to 48-bit PAs. A later patch in this series will add a kconfig dependency to ensure PAN is configured. In addition, when using 52-bit PA there is a special alignment requirement on the top-level table. We don't currently have any VA_BITS configuration that would violate the requirement, but one could be added in the future, so add a compile-time BUG_ON to check for it. Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [catalin.marinas@arm.com: added TTBR_BADD_MASK_52 comment] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-19PCI: Remove PCI_REASSIGN_ALL_RSRC use on arm and arm64Bjorn Helgaas1-4/+1
On arm, PCI_REASSIGN_ALL_RSRC is used only in pcibios_assign_all_busses(), which helps decide whether to reconfigure bridge bus numbers. It has nothing to do with BAR assignments. On arm64 and powerpc, pcibios_assign_all_busses() tests PCI_REASSIGN_ALL_BUS, which makes more sense. Align arm with arm64 and powerpc, so they all use PCI_REASSIGN_ALL_BUS for pcibios_assign_all_busses(). Remove PCI_REASSIGN_ALL_RSRC from the generic, Tegra, Versatile, and R-Car drivers. These drivers are used only on arm or arm64, where PCI_REASSIGN_ALL_RSRC is not used after this change, so removing it should have no effect. No functional change intended. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Manikanta Maddireddy <mmaddireddy@nvidia.com> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2017-12-18ARM: 8725/1: Add Broadcom Brahma-B15 readahead cache supportFlorian Fainelli2-0/+14
This patch adds support for the Broadcom Brahma-B15 CPU readahead cache controller. This cache controller sits between the L2 and the memory bus and its purpose is to provide a friendler burst size towards the DDR interface than the native cache line size. The readahead cache is mostly transparent, except for flush_kern_cache_all, which is precisely what we are overriding here. The readahead cache only intercepts reads, and does invalidate on writes (IOW), as such, some data can remain stale in any of its buffers, such that we need to flush it, which is an operation that needs to happen in a particular order: - disable the readahead cache - flush it - call the appropriate cache-v7.S function - re-enable This patch tries to minimize the impact to the cache-v7.S file by only providing a stub in case CONFIG_CACHE_B15_RAC is enabled (default for ARCH_BRCMSTB since it is the current user). Signed-off-by: Alamy Liu <alamyliu@broadcom.com> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-12-18ARM: probes: avoid adding kprobes to sensitive kernel-entry/exit codeRussell King3-14/+22
Avoid adding kprobes to any of the kernel entry/exit or startup assembly code, or code in the identity-mapped region. This code does not conform to the standard C conventions, which means that the expectations of the kprobes code is not forfilled. Placing kprobes at some of these locations results in the kernel trying to return to userspace addresses while retaining the CPU in kernel mode. Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-12-18ARM: 8723/2: always assume the "unified" syntax for assembly codeNicolas Pitre1-74/+3
The GNU assembler has implemented the "unified syntax" parsing since 2005. This "unified" syntax is required when the kernel is built in Thumb2 mode. However the "unified" syntax is a mixed bag of features, including not requiring a `#' prefix with immediate operands. This leads to situations where some code builds just fine in Thumb2 mode and fails to build in ARM mode if that prefix is missing. This behavior discrepancy makes build tests less valuable, forcing both ARM and Thumb2 builds for proper coverage. Let's "fix" this issue by always using the "unified" syntax for both ARM and Thumb2 mode. Given that the documented minimum binutils version that properly builds the kernel is version 2.20 released in 2010, we can assume that any toolchain capable of building the latest kernel is also "unified syntax" capable. Whith this, a bunch of macros used to mask some differences between both syntaxes can be removed, with the side effect of making LTO easier. Suggested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-12-10Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2-2/+6
Pull KVM fixes from Radim Krčmář: "ARM: - A number of issues in the vgic discovered using SMATCH - A bit one-off calculation in out stage base address mask (32-bit and 64-bit) - Fixes to single-step debugging instructions that trap for other reasons such as MMMIO aborts - Printing unavailable hyp mode as error - Potential spinlock deadlock in the vgic - Avoid calling vgic vcpu free more than once - Broken bit calculation for big endian systems s390: - SPDX tags - Fence storage key accesses from problem state - Make sure that irq_state.flags is not used in the future x86: - Intercept port 0x80 accesses to prevent host instability (CVE) - Use userspace FPU context for guest FPU (mainly an optimization that fixes a double use of kernel FPU) - Do not leak one page per module load - Flush APIC page address cache from MMU invalidation notifiers" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits) KVM: x86: fix APIC page invalidation KVM: s390: Fix skey emulation permission check KVM: s390: mark irq_state.flags as non-usable KVM: s390: Remove redundant license text KVM: s390: add SPDX identifiers to the remaining files KVM: VMX: fix page leak in hardware_setup() KVM: VMX: remove I/O port 0x80 bypass on Intel hosts x86,kvm: remove KVM emulator get_fpu / put_fpu x86,kvm: move qemu/guest FPU switching out to vcpu_run KVM: arm/arm64: Fix broken GICH_ELRSR big endian conversion KVM: arm/arm64: kvm_arch_destroy_vm cleanups KVM: arm/arm64: Fix spinlock acquisition in vgic_set_owner kvm: arm: don't treat unavailable HYP mode as an error KVM: arm/arm64: Avoid attempting to load timer vgic state without a vgic kvm: arm64: handle single-step of hyp emulated mmio instructions kvm: arm64: handle single-step during SError exceptions kvm: arm64: handle single-step of userspace mmio instructions kvm: arm64: handle single-stepping trapped instructions KVM: arm/arm64: debug: Introduce helper for single-step arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one ...
2017-12-05Merge tag 'kvm-arm-fixes-for-v4.15-1' of ↵Radim Krčmář2-2/+6
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm KVM/ARM Fixes for v4.15. Fixes: - A number of issues in the vgic discovered using SMATCH - A bit one-off calculation in out stage base address mask (32-bit and 64-bit) - Fixes to single-step debugging instructions that trap for other reasons such as MMMIO aborts - Printing unavailable hyp mode as error - Potential spinlock deadlock in the vgic - Avoid calling vgic vcpu free more than once - Broken bit calculation for big endian systems
2017-12-05bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program typeHendrik Brueckner1-0/+1
Commit 0515e5999a466dfe ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type") introduced the bpf_perf_event_data structure which exports the pt_regs structure. This is OK for multiple architectures but fail for s390 and arm64 which do not export pt_regs. Programs using them, for example, the bpf selftest fail to compile on these architectures. For s390, exporting the pt_regs is not an option because s390 wants to allow changes to it. For arm64, there is a user_pt_regs structure that covers parts of the pt_regs structure for use by user space. To solve the broken uapi for s390 and arm64, introduce an abstract type for pt_regs and add an asm/bpf_perf_event.h file that concretes the type. An asm-generic header file covers the architectures that export pt_regs today. The arch-specific enablement for s390 and arm64 follows in separate commits. Reported-by: Thomas Richter <tmricht@linux.vnet.ibm.com> Fixes: 0515e5999a466dfe ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type") Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-and-tested-by: Thomas Richter <tmricht@linux.vnet.ibm.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-30mm: switch to 'define pmd_write' instead of __HAVE_ARCH_PMD_WRITEDan Williams1-1/+0
In response to compile breakage introduced by a series that added the pud_write helper to x86, Stephen notes: did you consider using the other paradigm: In arch include files: #define pud_write pud_write static inline int pud_write(pud_t pud) ..... Then in include/asm-generic/pgtable.h: #ifndef pud_write tatic inline int pud_write(pud_t pud) { .... } #endif If you had, then the powerpc code would have worked ... ;-) and many of the other interfaces in include/asm-generic/pgtable.h are protected that way ... Given that some architecture already define pmd_write() as a macro, it's a net reduction to drop the definition of __HAVE_ARCH_PMD_WRITE. Link: http://lkml.kernel.org/r/151129126721.37405.13339850900081557813.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Oliver OHalloran <oliveroh@au1.ibm.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-29KVM: arm/arm64: debug: Introduce helper for single-stepAlex Bennée1-0/+5
After emulating instructions we may want return to user-space to handle single-step debugging. Introduce a helper function, which, if single-step is enabled, sets the run structure for return and returns true. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-29arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-oneMarc Zyngier1-2/+1
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") Cc: <stable@vger.kernel.org> # 3.9 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>
2017-11-29ARM: sa1111: map interrupt numbers through irqdomainRussell King1-1/+1
Map the interrupt numbers for SA1111 through the SA1111 IRQ domain rather than doing our own translation. This allows us to eliminate the irq_base sachip member. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-11-29ARM: sa1111: remove some redundant definitionsRussell King1-24/+0
SA1111_VBASE, SA1111_p2v, SA1111_v2p, _SA1111, SA1111_ADDR_WIDTH, SA1111_ADDR_MASK, and SA1111_DMA_ADDR are not used anywhere in the kernel, so remove these redundant definitions. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-11-29ARM: sa1111: remove special sa1111 mmio accessorsRussell King1-3/+0
Remove the special sa1111 mmio accessors from core sa1111 code, and their definition in sa1111.h now that all users are gone. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-11-29ARM: sa1111: remove legacy suspend/resume methodsRussell King1-2/+0
The legacy device-driver suspend/resume methods are not used by any of our drivers, so let's remove this redundant code. Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-11-27ARM: sa1111: remove legacy shutdown methodRussell King1-1/+0
Since the only user of the SA1111 device driver shutdown method has now gone, we can kill the bus level support code and the entry in the sa1111 device driver structure. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-11-27Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds2-0/+30
Pull ARM fixes from Russell King: - LPAE fixes for kernel-readonly regions - Fix for get_user_pages_fast on LPAE systems - avoid tying decompressor to a particular platform if DEBUG_LL is enabled - BUG if we attempt to return to userspace but the to-be-restored PSR value keeps us in privileged mode (defeating an issue that ftracetest found) * 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: BUG if jumping to usermode address in kernel mode ARM: 8722/1: mm: make STRICT_KERNEL_RWX effective for LPAE ARM: 8721/1: mm: dump: check hardware RO bit for LPAE ARM: make decompressor debug output user selectable ARM: fix get_user_pages_fast
2017-11-26ARM: BUG if jumping to usermode address in kernel modeRussell King1-0/+18
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>