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2016-03-02arm64: Rework valid_user_regsMark Rutland
We validate pstate using PSR_MODE32_BIT, which is part of the user-provided pstate (and cannot be trusted). Also, we conflate validation of AArch32 and AArch64 pstate values, making the code difficult to reason about. Instead, validate the pstate value based on the associated task. The task may or may not be current (e.g. when using ptrace), so this must be passed explicitly by callers. To avoid circular header dependencies via sched.h, is_compat_task is pulled out of asm/ptrace.h. To make the code possible to reason about, the AArch64 and AArch32 validation is split into separate functions. Software must respect the RES0 policy for SPSR bits, and thus the kernel mirrors the hardware policy (RAZ/WI) for bits as-yet unallocated. When these acquire an architected meaning writes may be permitted (potentially with additional validation). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Dave Martin <dave.martin@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-04-13arm64: Removed unused variableRichard Weinberger
arch/arm64/kernel/signal.c: In function ‘handle_signal’: arch/arm64/kernel/signal.c:290:22: warning: unused variable ‘thread’ [-Wunused-variable] Fixes: arm64: Remove signal translation and exec_domain Reported-by: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-12arm64: Remove signal translation and exec_domainRichard Weinberger
As execution domain support is gone we can remove signal translation from the signal code and remove exec_domain from thread_info. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-02-12all arches, signal: move restart_block to struct task_structAndy Lutomirski
If an attacker can cause a controlled kernel stack overflow, overwriting the restart block is a very juicy exploit target. This is because the restart_block is held in the same memory allocation as the kernel stack. Moving the restart block to struct task_struct prevents this exploit by making the restart_block harder to locate. Note that there are other fields in thread_info that are also easy targets, at least on some architectures. It's also a decent simplification, since the restart code is more or less identical on all architectures. [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack] Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: David Miller <davem@davemloft.net> Acked-by: Richard Weinberger <richard@nod.at> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Steven Miao <realmz6@gmail.com> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.linux@gmail.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06arm64: Use sigsp()Richard Weinberger
Use sigsp() instead of the open coded variant. Signed-off-by: Richard Weinberger <richard@nod.at>
2014-08-06arm64: Use get_signal() signal_setup_done()Richard Weinberger
Use the more generic functions get_signal() signal_setup_done() for signal delivery. Signed-off-by: Richard Weinberger <richard@nod.at>
2014-05-16Merge tag 'for-3.16' of git://git.linaro.org/people/ard.biesheuvel/linux-arm ↵Catalin Marinas
into upstream FPSIMD register bank context switching and crypto algorithms optimisations for arm64 from Ard Biesheuvel. * tag 'for-3.16' of git://git.linaro.org/people/ard.biesheuvel/linux-arm: arm64/crypto: AES-ECB/CBC/CTR/XTS using ARMv8 NEON and Crypto Extensions arm64: pull in <asm/simd.h> from asm-generic arm64/crypto: AES in CCM mode using ARMv8 Crypto Extensions arm64/crypto: AES using ARMv8 Crypto Extensions arm64/crypto: GHASH secure hash using ARMv8 Crypto Extensions arm64/crypto: SHA-224/SHA-256 using ARMv8 Crypto Extensions arm64/crypto: SHA-1 using ARMv8 Crypto Extensions arm64: add support for kernel mode NEON in interrupt context arm64: defer reloading a task's FPSIMD state to userland resume arm64: add abstractions for FPSIMD state manipulation asm-generic: allow generic unaligned access if the arch supports it Conflicts: arch/arm64/include/asm/thread_info.h
2014-05-12arm64: is_compat_task is defined both in asm/compat.h and linux/compat.hAKASHI Takahiro
Some kernel files may include both linux/compat.h and asm/compat.h directly or indirectly. Since both header files contain is_compat_task() under !CONFIG_COMPAT, compiling them with !CONFIG_COMPAT will eventually fail. Such files include kernel/auditsc.c, kernel/seccomp.c and init/do_mountfs.c (do_mountfs.c may read asm/compat.h via asm/ftrace.h once ftrace is implemented). So this patch proactively 1) removes is_compat_task() under !CONFIG_COMPAT from asm/compat.h 2) replaces asm/compat.h to linux/compat.h in kernel/*.c, but asm/compat.h is still necessary in ptrace.c and process.c because they use is_compat_thread(). Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-05-09arm64: Expose ESR_EL1 information to user when SIGSEGV/SIGBUSCatalin Marinas
This information is useful for instruction emulators to detect read/write and access size without having to decode the faulting instruction. The current patch exports it via sigcontext (struct esr_context) and is only valid for SIGSEGV and SIGBUS. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-05-09arm64: Remove the aux_context structureCatalin Marinas
This patch removes the aux_context structure (and the containing file) to allow the placement of the _aarch64_ctx end magic based on the context stored on the signal stack. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-05-08arm64: defer reloading a task's FPSIMD state to userland resumeArd Biesheuvel
If a task gets scheduled out and back in again and nothing has touched its FPSIMD state in the mean time, there is really no reason to reload it from memory. Similarly, repeated calls to kernel_neon_begin() and kernel_neon_end() will preserve and restore the FPSIMD state every time. This patch defers the FPSIMD state restore to the last possible moment, i.e., right before the task returns to userland. If a task does not return to userland at all (for any reason), the existing FPSIMD state is preserved and may be reused by the owning task if it gets scheduled in again on the same CPU. This patch adds two more functions to abstract away from straight FPSIMD register file saves and restores: - fpsimd_restore_current_state -> ensure current's FPSIMD state is loaded - fpsimd_flush_task_state -> invalidate live copies of a task's FPSIMD state Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-05-08arm64: add abstractions for FPSIMD state manipulationArd Biesheuvel
There are two tacit assumptions in the FPSIMD handling code that will no longer hold after the next patch that optimizes away some FPSIMD state restores: . the FPSIMD registers of this CPU contain the userland FPSIMD state of task 'current'; . when switching to a task, its FPSIMD state will always be restored from memory. This patch adds the following functions to abstract away from straight FPSIMD register file saves and restores: - fpsimd_preserve_current_state -> ensure current's FPSIMD state is saved - fpsimd_update_current_state -> replace current's FPSIMD state Where necessary, the signal handling and fork code are updated to use the above wrappers instead of poking into the FPSIMD registers directly. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2013-02-14arm64: switch to generic sigaltstackAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-23arm64: signal: return struct rt_sigframe from get_sigframeWill Deacon
We only have one type of frame (rt_sigframe) for arm64, so just return that type directly and dispense with the framesize argument, which is presumably a hangover from code copied from arch/arm/. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-11-23arm64: signal: push the unwinding prologue on the signal stackWill Deacon
To allow debuggers to unwind through signal frames, we create a fake stack unwinding prologue containing the link register and frame pointer of the interrupted context. The signal frame is then offset by 16 bytes to make room for the two saved registers which are pushed onto the frame of the *interrupted* context, rather than placed directly above the signal stack. This doesn't work when an alternative signal stack is set up for a SEGV handler, which is raised in response to RLIMIT_STACK being reached. In this case, we try to push the unwinding prologue onto the full stack and subsequently take a fault which we fail to resolve, causing setup_return to return -EFAULT and handle_signal to force_sigsegv on the current task. This patch fixes the problem by including the unwinding prologue as part of the rt_sigframe definition, which is populated during setup_sigframe, ensuring that it always ends up on the signal stack. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: <stable@vger.kernel.org>
2012-09-17arm64: Signal handling supportCatalin Marinas
This patch adds support for signal handling. The sigreturn is done via VDSO, introduced by a previous patch. The SA_RESTORER is still defined as it is required for 32-bit (compat) support but it is not to be used for 64-bit applications. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>