summaryrefslogtreecommitdiffstats
path: root/arch/arm/include/asm/uaccess.h
AgeCommit message (Collapse)AuthorFilesLines
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-23ARM: 8852/1: uaccess: use unified assembler language syntaxStefan Agner1-1/+2
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. Additionally, for GCC ".syntax unified" for inline assembly. When compiling non-Thumb2 GCC always emits a ".syntax divided" at the beginning of the inline assembly which makes the assembler fail. Since GCC 5 there is the -masm-syntax-unified GCC option which make GCC assume unified syntax asm and hence emits ".syntax unified" even in ARM mode. However, the option is broken since GCC version 6 (see GCC PR88648 [1]). Work around by adding ".syntax unified" as part of the inline assembly. [0] https://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html#index-masm-syntax-unified [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88648 Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-03-15Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds1-1/+2
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 ...
2019-03-04get rid of legacy 'get_ds()' functionLinus Torvalds1-1/+0
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 <jannh@google.com> Inspired-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-01ARM: 8828/1: uaccess: use unified assembler language syntaxStefan Agner1-1/+2
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 <stefan@agner.ch> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-01-05Merge tag 'for-4.21' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds1-0/+18
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 ...
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds1-2/+2
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 <torvalds@linux-foundation.org>
2018-11-12ARM: 8813/1: Make aligned 2-byte getuser()/putuser() atomic on ARMv6+Vincent Whitchurch1-0/+18
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 <vincent.whitchurch@axis.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-10-10Merge branches 'fixes', 'misc' and 'spectre' into for-nextRussell King1-6/+43
2018-10-05ARM: 8796/1: spectre-v1,v1.1: provide helpers for address sanitizationJulien Thierry1-0/+26
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>
2018-10-05ARM: 8795/1: spectre-v1.1: use put_user() for __put_user()Julien Thierry1-6/+9
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>
2018-10-05ARM: 8794/1: uaccess: Prevent speculative use of the current addr_limitJulien Thierry1-0/+8
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>
2018-08-13Merge branches 'fixes', 'misc' and 'spectre' into for-linusRussell King1-7/+19
Conflicts: arch/arm/include/asm/uaccess.h Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-08-02ARM: spectre-v1: use get_user() for __get_user()Russell King1-6/+11
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>
2018-08-02ARM: use __inttype() in get_user()Russell King1-1/+8
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>
2018-05-19ARM: 8768/1: uaccess: remove const to avoid duplicate specifierStefan Agner1-1/+1
Some users of get_user use the macro with an argument p which is already specified as static. When using clang this leads to a duplicate specifier: CC arch/arm/kernel/process.o In file included from init/do_mounts.c:15: In file included from ./include/linux/tty.h:7: In file included from ./include/uapi/linux/termios.h:6: In file included from ./arch/arm/include/generated/uapi/asm/termios.h:1: ./include/asm-generic/termios.h:25:6: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier] if (get_user(tmp, &termio->c_iflag) < 0) ^ ./arch/arm/include/asm/uaccess.h:195:3: note: expanded from macro 'get_user' __get_user_check(x, p); ^ ./arch/arm/include/asm/uaccess.h:155:12: note: expanded from macro '__get_user_check' register const typeof(*(p)) __user *__p asm("r0") = (p); Remove the const attribute from the register declaration to avoid the duplicate const specifier. In a test with ptrace.c and traps.c (both using get_user with non-const arguments for p) the generated code was exactly the same. Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-09-17Revert "arm/syscalls: Check address limit on user-mode return"Thomas Garnier1-2/+0
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
2017-09-04Merge branch 'x86-syscall-for-linus' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull syscall updates from Ingo Molnar: "Improve the security of set_fs(): we now check the address limit on a number of key platforms (x86, arm, arm64) before returning to user-space - without adding overhead to the typical system call fast path" * 'x86-syscall-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: arm64/syscalls: Check address limit on user-mode return arm/syscalls: Check address limit on user-mode return x86/syscalls: Check address limit on user-mode return
2017-07-15Merge branch 'work.uaccess-unaligned' of ↵Linus Torvalds1-7/+0
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull uacess-unaligned removal from Al Viro: "That stuff had just one user, and an exotic one, at that - binfmt_flat on arm and m68k" * 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: kill {__,}{get,put}_user_unaligned() binfmt_flat: flat_{get,put}_addr_from_rp() should be able to fail
2017-07-08arm/syscalls: Check address limit on user-mode returnThomas Garnier1-0/+2
Ensure the address limit is a user-mode segment before returning to user-mode. Otherwise a process can corrupt kernel-mode memory and elevate privileges [1]. The set_fs function sets the TIF_SETFS flag to force a slow path on return. In the slow path, the address limit is checked to be USER_DS if needed. The TIF_SETFS flag is added to _TIF_WORK_MASK shifting _TIF_SYSCALL_WORK for arm instruction immediate support. The global work mask is too big to used on a single instruction so adapt ret_fast_syscall. [1] https://bugs.chromium.org/p/project-zero/issues/detail?id=990 Signed-off-by: Thomas Garnier <thgarnie@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Rutland <mark.rutland@arm.com> Cc: kernel-hardening@lists.openwall.com Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: David Howells <dhowells@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Pratyush Anand <panand@redhat.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Petr Mladek <pmladek@suse.com> Cc: Rik van Riel <riel@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Will Drewry <wad@chromium.org> Cc: linux-api@vger.kernel.org Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Paolo Bonzini <pbonzini@redhat.com> Link: http://lkml.kernel.org/r/20170615011203.144108-2-thgarnie@google.com
2017-07-03kill {__,}{get,put}_user_unaligned()Al Viro1-7/+0
no users left Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-15kill strlen_user()Al Viro1-1/+0
no callers, no consistent semantics, no sane way to use it... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-28arm: switch to RAW_COPY_USERAl Viro1-46/+14
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-28arm: switch to generic extable.hAl Viro1-19/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-28new helper: uaccess_kernel()Al Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-05uaccess: drop duplicate includes from asm/uaccess.hAl Viro1-2/+0
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-05uaccess: move VERIFY_{READ,WRITE} definitions to linux/uaccess.hAl Viro1-3/+0
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-02-16ARM: 8657/1: uaccess: consistently check object sizesKees Cook1-12/+32
In commit 76624175dcae ("arm64: uaccess: consistently check object sizes"), the object size checks are moved outside the access_ok() so that bad destinations are detected before hitting the "memset(dest, 0, size)" in the copy_from_user() failure path. This makes the same change for arm, with attention given to possibly extracting the uaccess routines into a common header file for all architectures in the future. Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2016-09-15arm: don't zero in __copy_from_user_inatomic()/__copy_from_user()Al Viro1-5/+6
adjust copy_from_user(), obviously Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-08-08Merge tag 'usercopy-v4.8' of ↵Linus Torvalds1-2/+9
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull usercopy protection from Kees Cook: "Tbhis implements HARDENED_USERCOPY verification of copy_to_user and copy_from_user bounds checking for most architectures on SLAB and SLUB" * tag 'usercopy-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: mm: SLUB hardened usercopy support mm: SLAB hardened usercopy support s390/uaccess: Enable hardened usercopy sparc/uaccess: Enable hardened usercopy powerpc/uaccess: Enable hardened usercopy ia64/uaccess: Enable hardened usercopy arm64/uaccess: Enable hardened usercopy ARM: uaccess: Enable hardened usercopy x86/uaccess: Enable hardened usercopy mm: Hardened usercopy mm: Implement stack frame object validation mm: Add is_migrate_cma_page
2016-07-26ARM: uaccess: Enable hardened usercopyKees Cook1-2/+9
Enables CONFIG_HARDENED_USERCOPY checks on arm. Based on code from PaX and grsecurity. Signed-off-by: Kees Cook <keescook@chromium.org>
2016-06-22ARM: uaccess: remove put_user() code duplicationRussell King1-57/+49
Remove the code duplication between put_user() and __put_user(). The code which selected the implementation based upon the pointer size, and declared the local variable to hold the value to be put are common to both implementations. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-06-22ARM: 8580/1: Remove orphaned __addr_ok() definitionRobin Murphy1-8/+0
Since commit 8c56cc8be5b3 ("ARM: 7449/1: use generic strnlen_user and strncpy_from_user functions"), the definition of __addr_ok() has been languishing unused; eradicate the sucker. Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-12-15ARM: fix uaccess_with_memcpy() with SW_DOMAIN_PANRussell King1-0/+4
The uaccess_with_memcpy() code is currently incompatible with the SW PAN code: it takes locks within the region that we've changed the DACR, potentially sleeping as a result. As we do not save and restore the DACR across co-operative sleep events, can lead to an incorrect DACR value later in this code path. Reported-by: Peter Rosin <peda@axentia.se> Tested-by: Peter Rosin <peda@axentia.se> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-09-03Merge branches 'cleanup', 'fixes', 'misc', 'omap-barrier' and 'uaccess' into ↵Russell King1-5/+80
for-linus
2015-08-26ARM: software-based priviledged-no-access supportRussell King1-0/+14
Provide a software-based implementation of the priviledged no access support found in ARMv8.1. Userspace pages are mapped using a different domain number from the kernel and IO mappings. If we switch the user domain to "no access" when we enter the kernel, we can prevent the kernel from touching userspace. However, the kernel needs to be able to access userspace via the various user accessor functions. With the wrapping in the previous patch, we can temporarily enable access when the kernel needs user access, and re-disable it afterwards. This allows us to trap non-intended accesses to userspace, eg, caused by an inadvertent dereference of the LIST_POISON* values, which, with appropriate user mappings setup, can be made to succeed. This in turn can allow use-after-free bugs to be further exploited than would otherwise be possible. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-08-25ARM: uaccess: provide uaccess_save_and_enable() and uaccess_restore()Russell King1-5/+66
Provide uaccess_save_and_enable() and uaccess_restore() to permit control of userspace visibility to the kernel, and hook these into the appropriate places in the kernel where we need to access userspace. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-08-25ARM: uaccess: simplify user access assemblyRussell King1-35/+12
The user assembly for byte and word accesses was virtually identical. Rather than duplicating this, use a macro instead. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-03-29ARM: 8322/1: keep .text and .fixup regions closer togetherArd Biesheuvel1-5/+5
This moves all fixup snippets to the .text.fixup section, which is a special section that gets emitted along with the .text section for each input object file, i.e., the snippets are kept much closer to the code they refer to, which helps prevent linker failure on large kernels. Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-01-13arm: macro whitespace fixesMichael S. Tsirkin1-46/+46
While working on arch/arm/include/asm/uaccess.h, I noticed that some macros within this header are made harder to read because they violate a coding style rule: space is missing after comma. Fix it up. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-01-13arm: fix put_user sparse errorsMichael S. Tsirkin1-2/+2
virtio wants to write bitwise types to userspace using put_user. At the moment this triggers sparse errors, since the value is passed through an integer. For example: __le32 __user *p; __le32 x; put_user(x, p); is safe, but currently triggers a sparse warning. Fix that up using __force. Note: this does not suppress any useful sparse checks since caller assigns x to typeof(*p), which in turn forces all the necessary type checks. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-09-12ARM: 8137/1: fix get_user BE behavior for target variable with size of 8 bytesVictor Kamensky1-9/+39
e38361d 'ARM: 8091/2: add get_user() support for 8 byte types' commit broke V7 BE get_user call when target var size is 64 bit, but '*ptr' size is 32 bit or smaller. e38361d changed type of __r2 from 'register unsigned long' to 'register typeof(x) __r2 asm("r2")' i.e before the change even when target variable size was 64 bit, __r2 was still 32 bit. But after e38361d commit, for target var of 64 bit size, __r2 became 64 bit and now it should occupy 2 registers r2, and r3. The issue in BE case that r3 register is least significant word of __r2 and r2 register is most significant word of __r2. But __get_user_4 still copies result into r2 (most significant word of __r2). Subsequent code copies from __r2 into x, but for situation described it will pick up only garbage from r3 register. Special __get_user_64t_(124) functions are introduced. They are similar to corresponding __get_user_(124) function but result stored in r3 register (lsw in case of 64 bit __r2 in BE image). Those function are used by get_user macro in case of BE and target var size is 64bit. Also changed __get_user_lo8 name into __get_user_32t_8 to get consistent naming accross all cases. Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> Suggested-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-08-05Merge branch 'devel-stable' into for-nextRussell King1-1/+1
Conflicts: arch/arm/kernel/perf_event_cpu.c
2014-07-18ARM: 8091/2: add get_user() support for 8 byte typesDaniel Thompson1-1/+19
Recent contributions, including to DRM and binder, introduce 64-bit values in their interfaces. A common motivation for this is to allow the same ABI for 32- and 64-bit userspaces (and therefore also a shared ABI for 32/64 hybrid userspaces). Anyhow, the developers would like to avoid gotchas like having to use copy_from_user(). This feature is already implemented on x86-32 and the majority of other 32-bit architectures. The current list of get_user_8 hold out architectures are: arm, avr32, blackfin, m32r, metag, microblaze, mn10300, sh. Credit: My name sits rather uneasily at the top of this patch. The v1 and v2 versions of the patch were written by Rob Clark and to produce v4 I mostly copied code from Russell King and H. Peter Anvin. However I have mangled the patch sufficiently that *blame* is rightfully mine even if credit should more widely shared. Changelog: v5: updated to use the ret macro (requested by Russell King) v4: remove an inlined add on big endian systems (spotted by Russell King), used __ARMEB__ rather than BIG_ENDIAN (to match rest of file), cleared r3 on EFAULT during __get_user_8. v3: fix a couple of checkpatch issues v2: pass correct size to check_uaccess, and better handling of narrowing double word read with __get_user_xb() (Russell King's suggestion) v1: original Signed-off-by: Rob Clark <robdclark@gmail.com> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-01ARM: make user_addr_max more robustUwe Kleine-König1-1/+1
With CONFIG_MMU=y get_fs() returns current_thread_info()->addr_limit which is initialized as USER_DS (which in turn is defined to TASK_SIZE) for userspace processes. At least theoretically current_thread_info()->addr_limit is changable by set_fs() to a different limit, so checking for KERNEL_DS is more robust. With !CONFIG_MMU get_fs returns KERNEL_DS. To see what the old variant did you'd have to find out that USER_DS == KERNEL_DS which isn't needed any more with the variant this patch introduces. So it's a bit easier to understand, too. Also if the limit was changed this limit should be returned, not TASK_SIZE. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2014-05-25ARM: 8051/1: put_user: fix possible data corruption in put_userAndrey Ryabinin1-1/+2
According to arm procedure call standart r2 register is call-cloberred. So after the result of x expression was put into r2 any following function call in p may overwrite r2. To fix this, the result of p expression must be saved to the temporary variable before the assigment x expression to __r2. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Cc: stable@vger.kernel.org Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-02-10ARM: 7951/1: uaccess: use CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESSNicolas Pitre1-1/+1
Now that we select HAVE_EFFICIENT_UNALIGNED_ACCESS for ARMv6+ CPUs, replace the __LINUX_ARM_ARCH__ check in uaccess.h with the new symbol. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-09-18ARM: 7836/1: add __get_user_unaligned/__put_user_unalignedNicolas Pitre1-0/+7
BTRFS is now relying on those since v3.12-rc1. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-10-09ARM: warnings in arch/arm/include/asm/uaccess.hArnd Bergmann1-2/+2
On NOMMU ARM, the __addr_ok() and __range_ok() macros do not evaluate their arguments, which may lead to harmless build warnings in some code where the variables are not used otherwise. Adding a cast to void gets rid of the warning and does not make any semantic changes. Without this patch, building at91x40_defconfig results in: fs/read_write.c: In function 'rw_copy_check_uvector': fs/read_write.c:684:9: warning: unused variable 'buf' [-Wunused-variable] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Ungerer <gerg@uclinux.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk>
2012-09-09ARM: 7528/1: uaccess: annotate [__]{get,put}_user functions with might_fault()Will Deacon1-2/+16
The user access functions may generate a fault, resulting in invocation of a handler that may sleep. This patch annotates the accessors with might_fault() so that we print a warning if they are invoked from atomic context and help lockdep keep track of mmap_sem. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>