kernel.git/arch/arm/include/asm/uaccess.h, branch linux-5.1.y

Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

2019-03-15T21:37:46Z

Pull ARM updates from Russell King: - An improvement from Ard Biesheuvel, who noted that the identity map setup was taking a long time due to flush_cache_louis(). - Update a comment about dma_ops from Wolfram Sang. - Remove use of "-p" with ld, where this flag has been a no-op since 2004. - Remove the printing of the virtual memory layout, which is no longer useful since we hide pointers. - Correct SCU help text. - Remove legacy TWD registration method. - Add pgprot_device() implementation for mapping PCI sysfs resource files. - Initialise PFN limits earlier for kmemleak. - Fix argument count to match macro definition (affects clang builds) - Use unified assembler language almost everywhere for clang, and other clang improvements (from Stefan Agner, Nathan Chancellor). - Support security extension for noMMU and other noMMU cleanups (from Vladimir Murzin). - Remove unnecessary SMP bringup code (which was incorrectly copy'n' pasted from the ARM platform implementations) and remove it from the arch code to discourge further copys of it appearing. - Add Cortex A9 erratum preventing kexec working on some SoCs. - AMBA bus identification updates from Mike Leach. - More use of raw spinlocks to avoid -RT kernel issues (from Yang Shi and Sebastian Andrzej Siewior). - MCPM hyp/svc mode mismatch fixes from Marek Szyprowski. * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (32 commits) ARM: 8849/1: NOMMU: Fix encodings for PMSAv8's PRBAR4/PRLAR4 ARM: 8848/1: virt: Align GIC version check with arm64 counterpart ARM: 8847/1: pm: fix HYP/SVC mode mismatch when MCPM is used ARM: 8845/1: use unified assembler in c files ARM: 8844/1: use unified assembler in assembly files ARM: 8843/1: use unified assembler in headers ARM: 8841/1: use unified assembler in macros ARM: 8840/1: use a raw_spinlock_t in unwind ARM: 8839/1: kprobe: make patch_lock a raw_spinlock_t ARM: 8837/1: coresight: etmv4: Update ID register table to add UCI support ARM: 8836/1: drivers: amba: Update component matching to use the CoreSight UCI values. ARM: 8838/1: drivers: amba: Updates to component identification for driver matching. ARM: 8833/1: Ensure that NEON code always compiles with Clang ARM: avoid Cortex-A9 livelock on tight dmb loops ARM: smp: remove arch-provided "pen_release" ARM: actions: remove boot_lock and pen_release ARM: oxnas: remove CPU hotplug implementation ARM: qcom: remove unnecessary boot_lock ARM: 8832/1: NOMMU: Limit visibility for CONFIG_FLASH_{MEM_BASE,SIZE} ARM: 8831/1: NOMMU: pmsa-v8: remove unneeded semicolon ...

get rid of legacy 'get_ds()' function

2019-03-04T18:50:14Z

Every in-kernel use of this function defined it to KERNEL_DS (either as an actual define, or as an inline function). It's an entirely historical artifact, and long long long ago used to actually read the segment selector valueof '%ds' on x86. Which in the kernel is always KERNEL_DS. Inspired by a patch from Jann Horn that just did this for a very small subset of users (the ones in fs/), along with Al who suggested a script. I then just took it to the logical extreme and removed all the remaining gunk. Roughly scripted with git grep -l '(get_ds())' -- :^tools/ | xargs sed -i 's/(get_ds())/(KERNEL_DS)/' git grep -lw 'get_ds' -- :^tools/ | xargs sed -i '/^#define get_ds()/d' plus manual fixups to remove a few unusual usage patterns, the couple of inline function cases and to fix up a comment that had become stale. The 'get_ds()' function remains in an x86 kvm selftest, since in user space it actually does something relevant. Inspired-by: Jann Horn Inspired-by: Al Viro Signed-off-by: Linus Torvalds

ARM: 8828/1: uaccess: use unified assembler language syntax

2019-02-01T21:44:14Z

Convert the conditional infix to a postfix to make sure this inline assembly is unified syntax. Since gcc assumes non-unified syntax when emitting ARM instructions, make sure to define the syntax as unified. This allows to use LLVM's integrated assembler. Signed-off-by: Stefan Agner Signed-off-by: Russell King

Merge tag 'for-4.21' of git://git.armlinux.org.uk/~rmk/linux-arm

2019-01-05T19:23:17Z

Pull ARM updates from Russell King: "Included in this update: - Florian Fainelli noticed that userspace segfaults caused by the lack of kernel-userspace helpers was hard to diagnose; we now issue a warning when userspace tries to use the helpers but the kernel has them disabled. - Ben Dooks wants compatibility for the old ATAG serial number with DT systems. - Some cleanup of assembly by Nicolas Pitre. - User accessors optimisation from Vincent Whitchurch. - More robust kdump on SMP systems from Yufen Wang. - Sebastian Andrzej Siewior noticed problems with the SMP "boot_lock" on RT kernels, and so we convert the Versatile series of platforms to use a raw spinlock instead, consolidating the Versatile implementation. We entirely remove the boot_lock on OMAP systems, where it's unnecessary. Further patches for other systems will be submitted for the following merge window. - Start switching old StrongARM-11x0 systems to use gpiolib rather than their private GPIO implementation - mostly PCMCIA bits. - ARM Kconfig cleanups. - Cleanup a mostly harmless mistake in the recent Spectre patch in 4.20 (which had the effect that data that can be placed into the init sections was incorrectly always placed in the rodata section)" * tag 'for-4.21' of git://git.armlinux.org.uk/~rmk/linux-arm: (25 commits) ARM: omap2: remove unnecessary boot_lock ARM: versatile: rename and comment SMP implementation ARM: versatile: convert boot_lock to raw ARM: vexpress/realview: consolidate immitation CPU hotplug ARM: fix the cockup in the previous patch ARM: sa1100/cerf: switch to using gpio_led_register_device() ARM: sa1100/assabet: switch to using gpio leds ARM: sa1100/assabet: add gpio keys support for right-hand two buttons ARM: sa1111: remove legacy GPIO interfaces pcmcia: sa1100*: remove redundant bvd1/bvd2 setting ARM: pxa/lubbock: switch PCMCIA to MAX1600 library ARM: pxa/mainstone: switch PCMCIA to MAX1600 library and gpiod APIs ARM: sa1100/neponset: switch PCMCIA to MAX1600 library and gpiod APIs ARM: sa1100/jornada720: switch PCMCIA to gpiod APIs pcmcia: add MAX1600 library ARM: sa1100: explicitly register sa11x0-pcmcia devices ARM: 8813/1: Make aligned 2-byte getuser()/putuser() atomic on ARMv6+ ARM: 8812/1: Optimise copy_{from/to}_user for !CPU_USE_DOMAINS ARM: 8811/1: always list both ldrd/strd registers explicitly ARM: 8808/1: kexec:offline panic_smp_self_stop CPU ...

Remove 'type' argument from access_ok() function

2019-01-04T02:57:57Z

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds

ARM: 8813/1: Make aligned 2-byte getuser()/putuser() atomic on ARMv6+

2018-11-12T10:52:04Z

getuser() and putuser() (and there underscored variants) use two strb[t]/ldrb[t] instructions when they are asked to get/put 16-bits. This means that the read/write is not atomic even when performed to a 16-bit-aligned address. This leads to problems with vhost: vhost uses __getuser() to read the vring's 16-bit avail.index field, and if it happens to observe a partial update of the index, wrong descriptors will be used which will lead to a breakdown of the virtio communication. A similar problem exists for __putuser() which is used to write to the vring's used.index field. The reason these functions use strb[t]/ldrb[t] is because strht/ldrht instructions did not exist until ARMv6T2/ARMv7. So we should be easily able to fix this on ARMv7. Also, since all ARMv6 processors also don't actually use the unprivileged instructions anymore for uaccess (since CONFIG_CPU_USE_DOMAINS is not used) we can easily fix them too. Signed-off-by: Vincent Whitchurch Signed-off-by: Russell King

Merge branches 'fixes', 'misc' and 'spectre' into for-next

2018-10-10T12:53:33Z

ARM: 8796/1: spectre-v1,v1.1: provide helpers for address sanitization

2018-10-05T09:51:15Z

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 Signed-off-by: Russell King

ARM: 8795/1: spectre-v1.1: use put_user() for __put_user()

2018-10-05T09:51:15Z

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 Signed-off-by: Russell King

ARM: 8794/1: uaccess: Prevent speculative use of the current addr_limit

2018-10-05T09:51:15Z

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 Signed-off-by: Russell King