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2019-02-26ARM: 8844/1: use unified assembler in assembly filesStefan Agner1-1/+1
Use unified assembler syntax (UAL) in assembly files. Divided syntax is considered deprecated. This will also allow to build the kernel using LLVM's integrated assembler. Signed-off-by: Stefan Agner <stefan@agner.ch> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-10-10ARM: 8802/1: Call syscall_trace_exit even when system call skippedTimothy E Baldwin1-5/+4
On at least x86 and ARM64, and as documented in the ptrace man page a skipped system call will still cause a syscall exit ptrace stop. Previous to this commit 32-bit ARM did not, resulting in strace being confused when seccomp skips system calls. This change also impacts programs that use ptrace to skip system calls. Fixes: ad75b51459ae ("ARM: 7579/1: arch/allow a scno of -1 to not cause a SIGILL") Signed-off-by: Timothy E Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Signed-off-by: Eugene Syromyatnikov <evgsyr@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Eugene Syromyatnikov <evgsyr@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-07-30ARM: 8781/1: Fix Thumb-2 syscall return for binutils 2.29+Vincent Whitchurch1-1/+3
When building the kernel as Thumb-2 with binutils 2.29 or newer, if the assembler has seen the .type directive (via ENDPROC()) for a symbol, it automatically handles the setting of the lowest bit when the symbol is used with ADR. The badr macro on the other hand handles this lowest bit manually. This leads to a jump to a wrong address in the wrong state in the syscall return path: Internal error: Oops - undefined instruction: 0 [#2] SMP THUMB2 Modules linked in: CPU: 0 PID: 652 Comm: modprobe Tainted: G D 4.18.0-rc3+ #8 PC is at ret_fast_syscall+0x4/0x62 LR is at sys_brk+0x109/0x128 pc : [<80101004>] lr : [<801c8a35>] psr: 60000013 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 50c5387d Table: 9e82006a DAC: 00000051 Process modprobe (pid: 652, stack limit = 0x(ptrval)) 80101000 <ret_fast_syscall>: 80101000: b672 cpsid i 80101002: f8d9 2008 ldr.w r2, [r9, #8] 80101006: f1b2 4ffe cmp.w r2, #2130706432 ; 0x7f000000 80101184 <local_restart>: 80101184: f8d9 a000 ldr.w sl, [r9] 80101188: e92d 0030 stmdb sp!, {r4, r5} 8010118c: f01a 0ff0 tst.w sl, #240 ; 0xf0 80101190: d117 bne.n 801011c2 <__sys_trace> 80101192: 46ba mov sl, r7 80101194: f5ba 7fc8 cmp.w sl, #400 ; 0x190 80101198: bf28 it cs 8010119a: f04f 0a00 movcs.w sl, #0 8010119e: f3af 8014 nop.w {20} 801011a2: f2af 1ea2 subw lr, pc, #418 ; 0x1a2 To fix this, add a new symbol name which doesn't have ENDPROC used on it and use that with badr. We can't remove the badr usage since that would would cause breakage with older binutils. Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-06-10Merge branch 'core-rseq-for-linus' of ↵Linus Torvalds1-6/+19
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull restartable sequence support from Thomas Gleixner: "The restartable sequences syscall (finally): After a lot of back and forth discussion and massive delays caused by the speculative distraction of maintainers, the core set of restartable sequences has finally reached a consensus. It comes with the basic non disputed core implementation along with support for arm, powerpc and x86 and a full set of selftests It was exposed to linux-next earlier this week, so it does not fully comply with the merge window requirements, but there is really no point to drag it out for yet another cycle" * 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rseq/selftests: Provide Makefile, scripts, gitignore rseq/selftests: Provide parametrized tests rseq/selftests: Provide basic percpu ops test rseq/selftests: Provide basic test rseq/selftests: Provide rseq library selftests/lib.mk: Introduce OVERRIDE_TARGETS powerpc: Wire up restartable sequences system call powerpc: Add syscall detection for restartable sequences powerpc: Add support for restartable sequences x86: Wire up restartable sequence system call x86: Add support for restartable sequences arm: Wire up restartable sequences system call arm: Add syscall detection for restartable sequences arm: Add restartable sequences support rseq: Introduce restartable sequences system call uapi/headers: Provide types_32_64.h
2018-06-06arm: Add syscall detection for restartable sequencesMathieu Desnoyers1-6/+19
Syscalls are not allowed inside restartable sequences, so add a call to rseq_syscall() at the very beginning of system call exiting path for CONFIG_DEBUG_RSEQ=y kernel. This could help us to detect whether there is a syscall issued inside restartable sequences. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Joel Fernandes <joelaf@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Watson <davejwatson@fb.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Chris Lameter <cl@linux.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Andrew Hunter <ahh@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Paul Turner <pjt@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Maurer <bmaurer@fb.com> Cc: linux-api@vger.kernel.org Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/20180602124408.8430-5-mathieu.desnoyers@efficios.com
2018-06-01ARM: spectre-v1: fix syscall entryRussell King1-11/+7
Prevent speculation at the syscall table decoding by clamping the index used to zero on invalid system call numbers, and using the csdb speculative barrier. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Mark Rutland <mark.rutland@arm.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com>
2017-12-18ARM: probes: avoid adding kprobes to sensitive kernel-entry/exit codeRussell King1-0/+1
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>
2017-11-16Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds1-9/+0
Pull ARM updates from Russell King: - add support for ELF fdpic binaries on both MMU and noMMU platforms - linker script cleanups - support for compressed .data section for XIP images - discard memblock arrays when possible - various cleanups - atomic DMA pool updates - better diagnostics of missing/corrupt device tree - export information to allow userspace kexec tool to place images more inteligently, so that the device tree isn't overwritten by the booting kernel - make early_printk more efficient on semihosted systems - noMMU cleanups - SA1111 PCMCIA update in preparation for further cleanups * 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (38 commits) ARM: 8719/1: NOMMU: work around maybe-uninitialized warning ARM: 8717/2: debug printch/printascii: translate '\n' to "\r\n" not "\n\r" ARM: 8713/1: NOMMU: Support MPU in XIP configuration ARM: 8712/1: NOMMU: Use more MPU regions to cover memory ARM: 8711/1: V7M: Add support for MPU to M-class ARM: 8710/1: Kconfig: Kill CONFIG_VECTORS_BASE ARM: 8709/1: NOMMU: Disallow MPU for XIP ARM: 8708/1: NOMMU: Rework MPU to be mostly done in C ARM: 8707/1: NOMMU: Update MPU accessors to use cp15 helpers ARM: 8706/1: NOMMU: Move out MPU setup in separate module ARM: 8702/1: head-common.S: Clear lr before jumping to start_kernel() ARM: 8705/1: early_printk: use printascii() rather than printch() ARM: 8703/1: debug.S: move hexbuf to a writable section ARM: add additional table to compressed kernel ARM: decompressor: fix BSS size calculation pcmcia: sa1111: remove special sa1111 mmio accessors pcmcia: sa1111: use sa1111_get_irq() to obtain IRQ resources ARM: better diagnostics with missing/corrupt dtb ARM: 8699/1: dma-mapping: Remove init_dma_coherent_pool_size() ARM: 8698/1: dma-mapping: Mark atomic_pool as __ro_after_init ..
2017-09-28ARM: 8695/1: entry: Remove dead code in sys_mmap2Vladimir Murzin1-9/+0
We support page size of 4K only, remove dead code. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-09-17arm/syscalls: Optimize address limit checkThomas Garnier1-0/+11
Disable the generic address limit check in favor of an architecture specific optimized implementation. The generic implementation using pending work flags did not work well with ARM and alignment faults. The address limit is checked on each syscall return path to user-mode path as well as the irq user-mode return function. If the address limit was changed, a function is called to report data corruption (stopping the kernel or process based on configuration). The address limit check has to be done before any pending work because they can reset the address limit and the process is killed using a SIGKILL signal. For example the lkdtm address limit check does not work because the signal to kill the process will reset the user-mode address limit. Signed-off-by: Thomas Garnier <thgarnie@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Leonard Crestez <leonard.crestez@nxp.com> Reviewed-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/1504798247-48833-4-git-send-email-keescook@chromium.org
2017-09-17Revert "arm/syscalls: Check address limit on user-mode return"Thomas Garnier1-7/+2
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
2017-09-12Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds1-13/+31
Pull ARM updates from Russell King: "Low priority fixes and updates for ARM: - add some missing includes - efficiency improvements in system call entry code when tracing is enabled - ensure ARMv6+ is always built as EABI - export save_stack_trace_tsk() - fix fatal signal handling during mm fault - build translation table base address register from scratch - appropriately align the .data section to a word boundary where we rely on that data being word aligned" * 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: 8691/1: Export save_stack_trace_tsk() ARM: 8692/1: mm: abort uaccess retries upon fatal signal ARM: 8690/1: lpae: build TTB control register value from scratch in v7_ttb_setup ARM: align .data section ARM: always enable AEABI for ARMv6+ ARM: avoid saving and restoring registers unnecessarily ARM: move PC value into r9 ARM: obtain thread info structure later ARM: use aliases for registers in entry-common ARM: 8689/1: scu: add missing errno include ARM: 8688/1: pm: add missing types include
2017-08-02ARM: avoid saving and restoring registers unnecessarilyRussell King1-2/+8
Avoid repeatedly saving and restoring registers around the calls to trace_hardirqs_on() and context_tracking_user_exit(). With the previous changes, we no longer need to preserve "lr" across these calls, and if we re-load r0-r3 later, we can avoid preserving these regsiters too. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-08-02ARM: move PC value into r9Russell King1-0/+7
Move the saved PC value into r9, thereby moving it into a caller-saved register for functions that we may call during the entry to a syscall. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-08-02ARM: obtain thread info structure laterRussell King1-1/+2
Obtain the thread info structure later in the syscall processing, so that we free up a register for earlier code. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-08-02ARM: use aliases for registers in entry-commonRussell King1-10/+14
Use aliases for the saved (and preserved) PSR and PC values so that we can control which registers are used. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-07-08arm/syscalls: Check address limit on user-mode returnThomas Garnier1-2/+7
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
2016-10-18ARM: convert to generated system call tablesRussell King1-32/+44
Convert ARM to use a similar mechanism to x86 to generate the unistd.h system call numbers and the various kernel system call tables. This means that rather than having to edit three places (asm/unistd.h for the total number of system calls, uapi/asm/unistd.h for the system call numbers, and arch/arm/kernel/calls.S for the call table) we have only one place to edit, making the process much more simple. The scripts have knowledge of the table padding requirements, so there's no need to worry about __NR_syscalls not fitting within the immediate constant field of ALU instructions anymore. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2016-06-22ARM: rename S_FRAME_SIZE to PT_REGS_SIZERussell King1-1/+1
S_FRAME_SIZE is no longer the size of the kernel stack frame, so this name is misleading. It is the size of the kernel pt_regs structure. Name it so. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2015-09-03Merge branches 'cleanup', 'fixes', 'misc', 'omap-barrier' and 'uaccess' into ↵Russell King1-0/+3
for-linus
2015-08-26ARM: entry: provide uaccess assembly macro hooksRussell King1-0/+2
Provide hooks into the kernel entry and exit paths to permit control of userspace visibility to the kernel. The intended use is: - on entry to kernel from user, uaccess_disable will be called to disable userspace visibility - on exit from kernel to user, uaccess_enable will be called to enable userspace visibility - on entry from a kernel exception, uaccess_save_and_disable will be called to save the current userspace visibility setting, and disable access - on exit from a kernel exception, uaccess_restore will be called to restore the userspace visibility as it was before the exception occurred. These hooks allows us to keep userspace visibility disabled for the vast majority of the kernel, except for localised regions where we want to explicitly access userspace. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-08-25ARM: entry: ensure that IRQs are enabled when calling syscall_trace_exit()Russell King1-1/+1
The audit code looks like it's been written to cope with being called with IRQs enabled. However, it's unclear whether IRQs should be enabled or disabled when calling the syscall tracing infrastructure. Right now, sometimes we call this with IRQs enabled, and other times with IRQs disabled. Opt for IRQs being enabled for consistency. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-08-25ARM: entry: efficiency cleanupsRussell King1-16/+45
Make the "fast" syscall return path fast again. The addition of IRQ tracing and context tracking has made this path grossly inefficient. We can do much better if these options are enabled if we save the syscall return code on the stack - we then don't need to save a bunch of registers around every single callout to C code. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-08-07ARM: 8409/1: Mark ret_fast_syscall as a functionDrew Richardson1-0/+1
ret_fast_syscall runs when user space makes a syscall. However it needs to be marked as such so the ELF information is correct. Before it was: 101: 8000f300 0 NOTYPE LOCAL DEFAULT 2 ret_fast_syscall But with this change it correctly shows as: 101: 8000f300 96 FUNC LOCAL DEFAULT 2 ret_fast_syscall I see this function when using perf to unwind call stacks from kernel space to user space. Without this change I would need to add some special case logic when using the vmlinux ELF information. Signed-off-by: Drew Richardson <drew.richardson@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-12Merge branch 'bsym' into for-nextRussell King1-3/+3
Conflicts: arch/arm/kernel/head.S
2015-05-15ARM: fix missing syscall trace exitRussell King1-1/+3
Josh Stone reports: I've discovered a case where both arm and arm64 will miss a ptrace syscall-exit that they should report. If the syscall is entered without TIF_SYSCALL_TRACE set, then it goes on the fast path. It's then possible to have TIF_SYSCALL_TRACE added in the middle of the syscall, but ret_fast_syscall doesn't check this flag again. Fix this by always checking for a syscall trace in the fast exit path. Reported-by: Josh Stone <jistone@redhat.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-05-08ARM: replace BSYM() with badr assembly macroRussell King1-3/+3
BSYM() was invented to allow us to work around a problem with the assembler, where local symbols resolved by the assembler for the 'adr' instruction did not take account of their ISA. Since we don't want BSYM() used elsewhere, replace BSYM() with a new macro 'badr', which is like the 'adr' pseudo-op, but with the BSYM() mechanics integrated into it. This ensures that the BSYM()-ification is only used in conjunction with 'adr'. Acked-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-11-21ARM: move ftrace assembly code to separate fileRussell King1-235/+0
The ftrace assembly code doesn't need to live in entry-common.S and be surrounded with #ifdef CONFIG_FUNCTION_TRACER. Instead, move it to its own file and conditionally assemble it. Tested-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-09-26ARM: Avoid writing to control register on every exceptionRussell King1-1/+1
If we are not changing the control register value, avoid writing to it. Writes to the control register can be very expensive, taking around a hundred cycles or so. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-18ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+Russell King1-6/+7
ARMv6 and greater introduced a new instruction ("bx") which can be used to return from function calls. Recent CPUs perform better when the "bx lr" instruction is used rather than the "mov pc, lr" instruction, and this sequence is strongly recommended to be used by the ARM architecture manual (section A.4.1.1). We provide a new macro "ret" with all its variants for the condition code which will resolve to the appropriate instruction. Rather than doing this piecemeal, and miss some instances, change all the "mov pc" instances to use the new macro, with the exception of the "movs" instruction and the kprobes code. This allows us to detect the "mov pc, lr" case and fix it up - and also gives us the possibility of deploying this for other registers depending on the CPU selection. Reported-by: Will Deacon <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-06-02ARM: consolidate last remaining open-coded alignment trap enableRussell King1-7/+1
We can use the alignment_trap assembly macro here too. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-10-19ARM: asm: Add ARM_BE8() assembly helperBen Dooks1-3/+1
Add ARM_BE8() helper to wrap any code conditional on being compile when CONFIG_ARM_ENDIAN_BE8 is selected and convert existing places where this is to use it. Acked-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
2013-09-21ARM: 7839/1: entry: fix tracing of ARM-private syscallsWill Deacon1-2/+2
Commit 377747c40657 ("ARM: entry: allow ARM-private syscalls to be restarted") reworked the low-level syscall dispatcher to allow restarting of ARM-private syscalls. Unfortunately, this relocated the label used to dispatch a private syscall from the trace path, so that the invocation would be bypassed altogether! This causes applications to fail under strace as soon as they rely on a private syscall (e.g. set_tls): set_tls(0xb6fad4c0, 0xb6fadb98, 0xb6fb1050, 0xb6fad4c0, 0xb6fb1050) = -1 ENOSYS (Function not implemented) This patch fixes the label so that we correctly dispatch private syscalls from the trace path. Reported-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Tested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-07-22ARM: entry: allow ARM-private syscalls to be restartedWill Deacon1-2/+2
System calls will only be restarted after signal handling if they (a) return an error code indicating that a restart is required and (b) have `why' set to a non-zero value, to indicate that the signal interrupted them. This patch leaves `why' set to a non-zero value for ARM-private syscalls , and only zeroes it for syscalls that are not implemented. Signed-off-by: Will Deacon <will.deacon@arm.com>
2013-06-29Merge branch 'devel-stable' into for-nextRussell King1-0/+4
Conflicts: arch/arm/Makefile arch/arm/include/asm/glue-proc.h
2013-06-17ARM: 7748/1: oabi: handle faults when loading swi instruction from userspaceWill Deacon1-13/+29
Running an OABI_COMPAT kernel on an SMP platform can lead to fun and games with page aging. If one CPU issues a swi instruction immediately before another CPU decides to mkold the page containing the swi instruction, then we will fault attempting to load the instruction during the vector_swi handler in order to retrieve its immediate field. Since this fault is not currently dealt with by our exception tables, this results in a panic: Unable to handle kernel paging request at virtual address 4020841c pgd = c490c000 [4020841c] *pgd=84451831, *pte=bf05859d, *ppte=00000000 Internal error: Oops: 17 [#1] PREEMPT SMP ARM Modules linked in: hid_sony(O) CPU: 1 Tainted: G W O (3.4.0-perf-gf496dca-01162-gcbcc62b #1) PC is at vector_swi+0x28/0x88 LR is at 0x40208420 This patch wraps all of the swi instruction loads with the USER macro and provides a shared exception table entry which simply rewinds the saved user PC and returns from the system call (without setting tbl, so there's no worries with tracing or syscall restarting). Returning to userspace will re-enter the page fault handler, from where we will probably send SIGSEGV to the current task. Reported-by: Wang, Yalin <yalin.wang@sonymobile.com> Reviewed-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>
2013-05-22Merge branch 'for-next' of git://git.pengutronix.de/git/ukl/linux into ↵Russell King1-0/+4
devel-stable Pull ARM-v7M support from Uwe Kleine-König: "All but the last patch were in next since next-20130418 without issues. The last patch fixes a problem in combination with 8164f7a (ARM: 7680/1: Detect support for SDIV/UDIV from ISAR0 register) which triggers a WARN_ON without an implemented read_cpuid_ext. The branch merges fine into v3.10-rc1 and I'd be happy if you pulled it for 3.11-rc1. The only missing piece to be able to run a Cortex-M3 is the irqchip driver that will go in via Thomas Gleixner and platform specific stuff."
2013-05-03Merge branches 'devel-stable', 'entry', 'fixes', 'mach-types', 'misc' and ↵Russell King1-4/+16
'smp-hotplug' into for-linus
2013-04-17ARM: ARMv7-M: Add support for exception handlingUwe Kleine-König1-0/+4
This patch implements the exception handling for the ARMv7-M architecture (pretty different from the A or R profiles). It bases on work done earlier by Catalin for 2.6.33 but was nearly completely rewritten to use a pt_regs layout compatible to the A profile. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Jonathan Austin <jonathan.austin@arm.com> Tested-by: Jonathan Austin <jonathan.austin@arm.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2013-04-03ARM: 7688/1: add support for context tracking subsystemKevin Hilman1-0/+3
commit 91d1aa43 (context_tracking: New context tracking susbsystem) generalized parts of the RCU userspace extended quiescent state into the context tracking subsystem. Context tracking is then used to implement adaptive tickless (a.k.a extended nohz) To support the new context tracking subsystem on ARM, the user/kernel boundary transtions need to be instrumented. For exceptions and IRQs in usermode, the existing usr_entry macro is used to instrument the user->kernel transition. For the return to usermode path, the ret_to_user* path is instrumented. Using the usr_entry macro, this covers interrupts in userspace, data abort and prefetch abort exceptions in userspace as well as undefined exceptions in userspace (which is where FP emulation and VFP are handled.) For syscalls, the slow return path is covered by instrumenting the ret_to_user path. In addition, the syscall entry point is instrumented which covers the user->kernel transition for both fast and slow syscalls, and an additional instrumentation point is added for the fast syscall return path (ret_fast_syscall). Cc: Mats Liljegren <mats.liljegren@enea.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-04-03ARM: entry-common: get rid of unnecessary ifdefsRussell King1-4/+1
The contents of the asm_trace_hardirqs_on is already conditional on CONFIG_TRACE_IRQFLAGS. There's little point also making the use of the macro conditional as well. Get rid of these ifdefs to make the code easier to read. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-04-03ARM: 7689/1: add unwind annotations to ftrace asmRabin Vincent1-0/+12
Add unwind annotations to the ftrace assembly code so that the function tracer's stacktracing options (func_stack_trace, etc.) work when CONFIG_ARM_UNWIND is enabled. Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-02-04arm: switch to generic sigaltstackAl Viro1-5/+0
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-13Merge branch 'for-linus' of ↵Linus Torvalds1-16/+0
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull big execve/kernel_thread/fork unification series from Al Viro: "All architectures are converted to new model. Quite a bit of that stuff is actually shared with architecture trees; in such cases it's literally shared branch pulled by both, not a cherry-pick. A lot of ugliness and black magic is gone (-3KLoC total in this one): - kernel_thread()/kernel_execve()/sys_execve() redesign. We don't do syscalls from kernel anymore for either kernel_thread() or kernel_execve(): kernel_thread() is essentially clone(2) with callback run before we return to userland, the callbacks either never return or do successful do_execve() before returning. kernel_execve() is a wrapper for do_execve() - it doesn't need to do transition to user mode anymore. As a result kernel_thread() and kernel_execve() are arch-independent now - they live in kernel/fork.c and fs/exec.c resp. sys_execve() is also in fs/exec.c and it's completely architecture-independent. - daemonize() is gone, along with its parts in fs/*.c - struct pt_regs * is no longer passed to do_fork/copy_process/ copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump. - sys_fork()/sys_vfork()/sys_clone() unified; some architectures still need wrappers (ones with callee-saved registers not saved in pt_regs on syscall entry), but the main part of those suckers is in kernel/fork.c now." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits) do_coredump(): get rid of pt_regs argument print_fatal_signal(): get rid of pt_regs argument ptrace_signal(): get rid of unused arguments get rid of ptrace_signal_deliver() arguments new helper: signal_pt_regs() unify default ptrace_signal_deliver flagday: kill pt_regs argument of do_fork() death to idle_regs() don't pass regs to copy_process() flagday: don't pass regs to copy_thread() bfin: switch to generic vfork, get rid of pointless wrappers xtensa: switch to generic clone() openrisc: switch to use of generic fork and clone unicore32: switch to generic clone(2) score: switch to generic fork/vfork/clone c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone() take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h mn10300: switch to generic fork/vfork/clone h8300: switch to generic fork/vfork/clone tile: switch to generic clone() ... Conflicts: arch/microblaze/include/asm/Kbuild
2012-12-11Merge branches 'cache-l2x0', 'fixes', 'hdrs', 'misc', 'mmci', 'vic' and ↵Russell King1-14/+6
'warnings' into for-next
2012-12-11ARM: 7595/1: syscall: rework ordering in syscall_trace_exitWill Deacon1-1/+0
syscall_trace_exit is currently doing things back-to-front; invoking the audit hook *after* signalling the debugger, which presents an opportunity for the registers to be re-written by userspace in order to bypass auditing constaints. This patch fixes the ordering by moving the audit code first and the tracehook code last. On the face of it, it looks like current_thread_info()->syscall may be incorrect for the sys_exit tracepoint, but that's actually not an issue because it will have been set during syscall entry and cannot have changed since then. Reported-by: Andrew Gabbasov <Andrew_Gabbasov@mentor.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-11-29arm: switch to generic fork/vfork/cloneAl Viro1-16/+0
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-19ARM: 7579/1: arch/allow a scno of -1 to not cause a SIGILLKees Cook1-1/+4
On tracehook-friendly platforms, a system call number of -1 falls through without running much code or taking much action. ARM is different. This adds a short-circuit check in the trace path to avoid any additional work, as suggested by Russell King, to make sure that ARM behaves the same way as other platforms. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Will Drewry <wad@chromium.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-11-19ARM: 7578/1: arch/move secure_computing into traceKees Cook1-10/+0
There is very little difference in the TIF_SECCOMP and TIF_SYSCALL_WORK path in entry-common.S, so merge TIF_SECCOMP into TIF_SYSCALL_WORK and move seccomp into the syscall_trace_enter() handler. Expanded some of the tracehook logic into the callers to make this code more readable. Since tracehook needs to do register changing, this portion is best left in its own function instead of copy/pasting into the callers. Additionally, the return value for secure_computing() is now checked and a -1 value will result in the system call being skipped. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Will Drewry <wad@chromium.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-10-15ARM: fix oops on initial entry to userspace with Thumb2 kernelsRussell King1-2/+2
Daniel Mack reports an oops at boot with the latest kernels: Internal error: Oops - undefined instruction: 0 [#1] SMP THUMB2 Modules linked in: CPU: 0 Not tainted (3.6.0-11057-g584df1d #145) PC is at cpsw_probe+0x45a/0x9ac LR is at trace_hardirqs_on_caller+0x8f/0xfc pc : [<c03493de>] lr : [<c005e81f>] psr: 60000113 sp : cf055fb0 ip : 00000000 fp : 00000000 r10: 00000000 r9 : 00000000 r8 : 00000000 r7 : 00000000 r6 : 00000000 r5 : c0344555 r4 : 00000000 r3 : cf057a40 r2 : 00000000 r1 : 00000001 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 50c5387d Table: 8f3f4019 DAC: 00000015 Process init (pid: 1, stack limit = 0xcf054240) Stack: (0xcf055fb0 to 0xcf056000) 5fa0: 00000001 00000000 00000000 00000000 5fc0: cf055fb0 c000d1a8 00000000 00000000 00000000 00000000 00000000 00000000 5fe0: 00000000 be9b3f10 00000000 b6f6add0 00000010 00000000 aaaabfaf a8babbaa The analysis of this is as follows. In init/main.c, we issue: kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND); This creates a new thread, which falls through to the ret_from_fork assembly, with r4 set NULL and r5 set to kernel_init. You can see this in your oops dump register set - r5 is 0xc0344555, which is the address of kernel_init plus 1 which marks the function as Thumb code. Now, let's look at this code a little closer - this is what the disassembly looks like: c000d180 <ret_from_fork>: c000d180: f03a fe08 bl c0047d94 <schedule_tail> c000d184: 2d00 cmp r5, #0 c000d186: bf1e ittt ne c000d188: 4620 movne r0, r4 c000d18a: 46fe movne lr, pc <-- XXXXXXX c000d18c: 46af movne pc, r5 c000d18e: 46e9 mov r9, sp c000d190: ea4f 3959 mov.w r9, r9, lsr #13 c000d194: ea4f 3949 mov.w r9, r9, lsl #13 c000d198: e7c8 b.n c000d12c <ret_to_user> c000d19a: bf00 nop c000d19c: f3af 8000 nop.w This code was introduced in 9fff2fa0db911 (arm: switch to saner kernel_execve() semantics). I have marked one instruction, and it's the significant one - I'll come back to that later. Eventually, having had a successful call to kernel_execve(), kernel_init() returns zero. In returning, it uses the value in 'lr' which was set by the instruction I marked above. Unfortunately, this causes lr to contain 0xc000d18e - an even address. This switches the ISA to ARM on return but with a non word aligned PC value. So, what do we end up executing? Well, not the instructions above - yes the opcodes, but they don't mean the same thing in ARM mode. In ARM mode, it looks like this instead: c000d18c: 46e946af strbtmi r4, [r9], pc, lsr #13 c000d190: 3959ea4f ldmdbcc r9, {r0, r1, r2, r3, r6, r9, fp, sp, lr, pc}^ c000d194: 3949ea4f stmdbcc r9, {r0, r1, r2, r3, r6, r9, fp, sp, lr, pc}^ c000d198: bf00e7c8 svclt 0x0000e7c8 c000d19c: 8000f3af andhi pc, r0, pc, lsr #7 c000d1a0: e88db092 stm sp, {r1, r4, r7, ip, sp, pc} c000d1a4: 46e81fff ; <UNDEFINED> instruction: 0x46e81fff c000d1a8: 8a00f3ef bhi 0xc004a16c c000d1ac: 0a0cf08a beq 0xc03493dc I have included more above, because it's relevant. The PSR flags which we can see in the oops dump are nZCv, so Z and C are set. All the above ARM instructions are not executed, except for two. c000d1a0, which has no writeback, and writes below the current stack pointer (and that data is lost when we take the next exception.) The other instruction which is executed is c000d1ac, which takes us to... 0xc03493dc. However, remember that bit 1 of the PC got set. So that makes the PC value 0xc03493de. And that value is the value we find in the oops dump for PC. What is the instruction here when interpreted in ARM mode? 0: f71e150c ; <UNDEFINED> instruction: 0xf71e150c and there we have our undefined instruction (remember that the 'never' condition code, 0xf, has been deprecated and is now always executed as it is now being used for additional instructions.) This path also nicely explains the state of the stack we see in the oops dump too. The above is a consistent and sane story for how we got to the oops dump, which all stems from the instruction at 0xc000d18a being wrong. Reported-by: Daniel Mack <zonque@gmail.com> Tested-by: Daniel Mack <zonque@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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