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2015-10-16arm64: AArch32 user space PC alignment exceptionMark Salyzyn
ARMv7 does not have a PC alignment exception. ARMv8 AArch32 user space however can produce a PC alignment exception. Add handler so that we do not dump an unexpected stack trace in the logs. Signed-off-by: Mark Salyzyn <salyzyn@android.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-08-21arm64: entry: always restore x0 from the stack on syscall returnWill Deacon
We have a micro-optimisation on the fast syscall return path where we take care to keep x0 live with the return value from the syscall so that we can avoid restoring it from the stack. The benefit of doing this is fairly suspect, since we will be restoring x1 from the stack anyway (which lives adjacent in the pt_regs structure) and the only additional cost is saving x0 back to pt_regs after the syscall handler, which could be seen as a poor man's prefetch. More importantly, this causes issues with the context tracking code. The ct_user_enter macro ends up branching into C code, which is free to use x0 as a scratch register and consequently leads to us returning junk back to userspace as the syscall return value. Rather than special case the context-tracking code, this patch removes the questionable optimisation entirely. Cc: <stable@vger.kernel.org> Cc: Larry Bassel <larry.bassel@linaro.org> Cc: Kevin Hilman <khilman@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Hanjun Guo <hanjun.guo@linaro.org> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: kernel: Adopt new alternative assembler macrosDaniel Thompson
Convert the dynamic patching for ARM64_WORKAROUND_845719 over to the newly added alternative assembler macros. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-22arm64: switch_to: calculate cpu context pointer using separate registerWill Deacon
Commit 0c8c0f03e3a2 ("x86/fpu, sched: Dynamically allocate 'struct fpu'") moved the thread_struct to the bottom of task_struct. As a result, the offset is now too large to be used in an immediate add on arm64 with some kernel configs: arch/arm64/kernel/entry.S: Assembler messages: arch/arm64/kernel/entry.S:588: Error: immediate out of range arch/arm64/kernel/entry.S:597: Error: immediate out of range This patch calculates the offset using an additional register instead of an immediate offset. Fixes: 0c8c0f03e3a2 ("x86/fpu, sched: Dynamically allocate 'struct fpu'") Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Olof Johansson <olof@lixom.net> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-07-08arm64: entry: handle debug exceptions in el*_invMark Rutland
Currently we enable debug exceptions before reading ESR_EL1 in both el0_inv and el1_inv. If a debug exception is taken before we read ESR_EL1, the value will have been corrupted. As el*_inv is typically fatal, an intervening debug exception results in misleading debug information being logged to the console, but is not otherwise harmful. As with the other entry paths, we can use the ESR_EL1 value stashed earlier in the exception entry (in x25 for el0_sync{,_compat}, and x1 for el1_sync), giving us better error reporting in this case. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-17arm64: entry: fix context tracking for el0_sp_pcMark Rutland
Commit 6c81fe7925cc4c42 ("arm64: enable context tracking") did not update el0_sp_pc to use ct_user_exit, but this appears to have been unintentional. In commit 6ab6463aeb5fbc75 ("arm64: adjust el0_sync so that a function can be called") we made x0 available, and in the return to userspace we call ct_user_enter in the kernel_exit macro. Due to this, we currently don't correctly inform RCU of the user->kernel transition, and may erroneously account for time spent in the kernel as if we were in an extended quiescent state when CONFIG_CONTEXT_TRACKING is enabled. As we do record the kernel->user transition, a userspace application making accesses from an unaligned stack pointer can demonstrate the imbalance, provoking the following warning: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 3660 at kernel/context_tracking.c:75 context_tracking_enter+0xd8/0xe4() Modules linked in: CPU: 2 PID: 3660 Comm: a.out Not tainted 4.1.0-rc7+ #8 Hardware name: ARM Juno development board (r0) (DT) Call trace: [<ffffffc000089914>] dump_backtrace+0x0/0x124 [<ffffffc000089a48>] show_stack+0x10/0x1c [<ffffffc0005b3cbc>] dump_stack+0x84/0xc8 [<ffffffc0000b3214>] warn_slowpath_common+0x98/0xd0 [<ffffffc0000b330c>] warn_slowpath_null+0x14/0x20 [<ffffffc00013ada4>] context_tracking_enter+0xd4/0xe4 [<ffffffc0005b534c>] preempt_schedule_irq+0xd4/0x114 [<ffffffc00008561c>] el1_preempt+0x4/0x28 [<ffffffc0001b8040>] exit_files+0x38/0x4c [<ffffffc0000b5b94>] do_exit+0x430/0x978 [<ffffffc0000b614c>] do_group_exit+0x40/0xd4 [<ffffffc0000c0208>] get_signal+0x23c/0x4f4 [<ffffffc0000890b4>] do_signal+0x1ac/0x518 [<ffffffc000089650>] do_notify_resume+0x5c/0x68 ---[ end trace 963c192600337066 ]--- This patch adds the missing ct_user_exit to the el0_sp_pc entry path, correcting the context tracking for this case. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Fixes: 6c81fe7925cc ("arm64: enable context tracking") Cc: <stable@vger.kernel.org> # v3.17+ Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-08arm64: fix missing syscall trace exitJosh Stone
If a 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. This causes a ptrace syscall-exit-stop to be missed. For instance, from a PTRACE_EVENT_FORK reported during do_fork, the tracer might resume with PTRACE_SYSCALL, setting TIF_SYSCALL_TRACE. Now the completion of the fork should have a syscall-exit-stop. Russell King fixed this on arm by re-checking _TIF_SYSCALL_WORK in the fast exit path. Do the same on arm64. Reviewed-by: Will Deacon <will.deacon@arm.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Josh Stone <jistone@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-05arm64: alternative: Merge alternative-asm.h into alternative.hMarc Zyngier
asm/alternative-asm.h and asm/alternative.h are extremely similar, and really deserve to live in the same file (as this makes further modufications a bit easier). Fold the content of alternative-asm.h into alternative.h, and update the few users. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-05arm64: Rework alternate sequence for ARM erratum 845719Marc Zyngier
The workaround for erratum 845719 is currently using a branch between two alternate sequences, which is quite fragile, and that we are going to break as we rework the alternative code. This patch reworks the workaround to fit in a single alternative sequence. The generated code itself is unchanged. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-04-01arm64: errata: add workaround for cortex-a53 erratum #845719Will Deacon
When running a compat (AArch32) userspace on Cortex-A53, a load at EL0 from a virtual address that matches the bottom 32 bits of the virtual address used by a recent load at (AArch64) EL1 might return incorrect data. This patch works around the issue by writing to the contextidr_el1 register on the exception return path when returning to a 32-bit task. This workaround is patched in at runtime based on the MIDR value of the processor. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-01-27arm64: Implement the compat_sys_call_table in CCatalin Marinas
Unlike the sys_call_table[], the compat one was implemented in sys32.S making it impossible to notice discrepancies between the number of compat syscalls and the __NR_compat_syscalls macro, the latter having to be defined in asm/unistd.h as including asm/unistd32.h would cause conflicts on __NR_* definitions. With this patch, incorrect __NR_compat_syscalls values will result in a build-time error. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com>
2015-01-15arm64: move to ESR_ELx macrosMark Rutland
Now that we have common ESR_ELx_* macros, move the core arm64 code over to them. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Peter Maydell <peter.maydell@linaro.org> Cc: Will Deacon <will.deacon@arm.com>
2014-11-28arm64: ptrace: allow tracer to skip a system callAKASHI Takahiro
If tracer modifies a syscall number to -1, this traced system call should be skipped with a return value specified in x0. This patch implements this semantics. Please note: * syscall entry tracing and syscall exit tracing (ftrace tracepoint and audit) are always executed, if enabled, even when skipping a system call (that is, -1). In this way, we can avoid a potential bug where audit_syscall_entry() might be called without audit_syscall_exit() at the previous system call being called, that would cause OOPs in audit_syscall_entry(). Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> [will: fixed up conflict with blr rework] Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-25arm64: Treat handle_arch_irq as a function pointerLaura Abbott
handle_arch_irq isn't actually text, it's just a function pointer. It doesn't need to be stored in the text section and doing so causes problesm if we ever want to make the kernel text read only. Declare handle_arch_irq as a proper function pointer stored in the data section. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-14arm64: entry: use ldp/stp instead of push/pop when saving/restoring regsWill Deacon
The push/pop instructions can be suboptimal when saving/restoring large amounts of data to/from the stack, for example on entry/exit from the kernel. This is because: (1) They act on descending addresses (i.e. the newly decremented sp), which may defeat some hardware prefetchers (2) They introduce an implicit dependency between each instruction, as the sp has to be updated in order to resolve the address of the next access. This patch removes the push/pop instructions from our kernel entry/exit macros in favour of ldp/stp plus offset. Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-14arm64: entry: avoid writing lr explicitly for constructing return pathsWill Deacon
Using an explicit adr instruction to set the link register to point at ret_fast_syscall/ret_to_user can defeat branch and return stack predictors. Instead, use the standard calling instructions (bl, blr) and have an unconditional branch as the following instruction. Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-09-23arm64: debug: don't re-enable debug exceptions on return from el1_dbgWill Deacon
When returning from a debug exception taken from EL1, we unmask debug exceptions after handling the exception. This is crucial for debug exceptions taken from EL0, so that any kernel work on the ret_to_user path can be debugged by kgdb. However, when returning back to EL1 the only thing left to do is to restore the original register state before the exception return. If single-step has been enabled by the debug exception handler, we will get stuck in an infinite debug exception loop, since we will take the step exception as soon as we unmask debug exceptions. This patch avoids unmasking debug exceptions on the debug exception return path when the exception was taken from EL1. Fixes: 2a2830703a23 (arm64: debug: avoid accessing mdscr_el1 on fault paths where possible) Cc: <stable@vger.kernel.org> #3.16+ Reported-by: David Long <dave.long@linaro.org> Reported-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>
2014-07-10arm64: Add __NR_* definitions for compat syscallsCatalin Marinas
This patch adds __NR_* definitions to asm/unistd32.h, moves the __NR_compat_* definitions to asm/unistd.h and removes all the explicit unistd32.h includes apart from the one building the compat syscall table. The aim is to have the compat __NR_* definitions available but without colliding with the native syscall definitions (required by lib/compat_audit.c to avoid duplicating the audit header files between native and compat). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-10arm64: enable context trackingLarry Bassel
Make calls to ct_user_enter when the kernel is exited and ct_user_exit when the kernel is entered (in el0_da, el0_ia, el0_svc, el0_irq and all of the "error" paths). These macros expand to function calls which will only work properly if el0_sync and related code has been rearranged (in a previous patch of this series). The calls to ct_user_exit are made after hw debugging has been enabled (enable_dbg_and_irq). The call to ct_user_enter is made at the beginning of the kernel_exit macro. This patch is based on earlier work by Kevin Hilman. Save/restore optimizations were also done by Kevin. Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Kevin Hilman <khilman@linaro.org> Tested-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Larry Bassel <larry.bassel@linaro.org> Signed-off-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-10arm64: adjust el0_sync so that a function can be calledLarry Bassel
To implement the context tracker properly on arm64, a function call needs to be made after debugging and interrupts are turned on, but before the lr is changed to point to ret_to_user(). If the function call is made after the lr is changed the function will not return to the correct place. For similar reasons, defer the setting of x0 so that it doesn't need to be saved around the function call (save far_el1 in x26 temporarily instead). Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Kevin Hilman <khilman@linaro.org> Tested-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Larry Bassel <larry.bassel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-06-18arm64: Bug fix in stack alignment exceptionChiaHao
The value of ESR has been stored into x1, and should be directly pass to do_sp_pc_abort function, "MOV x1, x25" is an extra operation and do_sp_pc_abort will get the wrong value of ESR. Signed-off-by: ChiaHao <andy.jhshiu@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: <stable@vger.kernel.org>
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: split syscall_trace() into separate functions for enter/exitAKASHI Takahiro
As done in arm, this change makes it easy to confirm we invoke syscall related hooks, including syscall tracepoint, audit and seccomp which would be implemented later, in correct order. That is, undoing operations in the opposite order on exit that they were done on entry. 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>
2014-05-12arm64: make a single hook to syscall_trace() for all syscall featuresAKASHI Takahiro
Currently syscall_trace() is called only for ptrace. With additional TIF_xx flags defined, it is now called in all the cases of audit, ftrace and seccomp in addition to ptrace. Acked-by: Richard Guy Briggs <rgb@redhat.com> 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>
2014-05-12arm64: debug: avoid accessing mdscr_el1 on fault paths where possibleWill Deacon
Since mdscr_el1 is part of the debug register group, it is highly likely to be trapped by a hypervisor to prevent virtual machines from debugging (buggering?) each other. Unfortunately, this absolutely destroys our performance, since we access the register on many of our low-level fault handling paths to keep track of the various debug state machines. This patch removes our dependency on mdscr_el1 in the case that debugging is not being used. More specifically we: - Use TIF_SINGLESTEP to indicate that a task is stepping at EL0 and avoid disabling step in the MDSCR when we don't need to. MDSCR_EL1.SS handling is moved to kernel_entry, when trapping from userspace. - Ensure debug exceptions are re-enabled on *all* exception entry paths, even the debug exception handling path (where we re-enable exceptions after invoking the handler). Since we can now rely on MDSCR_EL1.SS being cleared by the entry code, exception handlers can usually enable debug immediately before enabling interrupts. - Remove all debug exception unmasking from ret_to_user and el1_preempt, since we will never get here with debug exceptions masked. This results in a slight change to kernel debug behaviour, where we now step into interrupt handlers and data aborts from EL1 when debugging the kernel, which is actually a useful thing to do. A side-effect of this is that it *does* potentially prevent stepping off {break,watch}points when there is a high-frequency interrupt source (e.g. a timer), so a debugger would need to use either breakpoints or manually disable interrupts to get around this issue. With this patch applied, guest performance is restored under KVM when debug register accesses are trapped (and we get a measurable performance increase on the host on Cortex-A57 too). Cc: Ian Campbell <ian.campbell@citrix.com> Tested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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>
2014-01-13arm64: fix typo in entry.SNeil Zhang
Commit 64681787 (arm64: let the core code deal with preempt_count) changed the code, but left the comments unchanged, fix it. Signed-off-by: Neil Zhang <zhangwm@marvell.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19arm64: support single-step and breakpoint handler hooksSandeepa Prabhu
AArch64 Single Steping and Breakpoint debug exceptions will be used by multiple debug framworks like kprobes & kgdb. This patch implements the hooks for those frameworks to register their own handlers for handling breakpoint and single step events. Reworked the debug exception handler in entry.S: do_dbg to route software breakpoint (BRK64) exception to do_debug_exception() Signed-off-by: Sandeepa Prabhu <sandeepa.prabhu@linaro.org> Signed-off-by: Deepak Saxena <dsaxena@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-11-25arm64: let the core code deal with preempt_countMarc Zyngier
Commit f27dde8deef3 (sched: Add NEED_RESCHED to the preempt_count) introduced the use of bit 31 in preempt_count for obscure scheduling purposes. This causes interrupts taken from EL0 to hit the (open coded) BUG when this flag is flipped while handling the interrupt (we compare the values before and after, and kill the kernel if they are different). The fix is to stop messing with the preempt count entirely, as this is already being dealt with in the generic code (irq_enter/irq_exit). Tested on a dual A53 FPGA running cyclictest. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-11-05arm64: fix access to preempt_count from assembly codeMarc Zyngier
preempt_count is defined as an int. Oddly enough, we access it as a 64bit value. Things become interesting when running a BE kernel, and looking at the current CPU number, which is stored as an int next to preempt_count. Like in a per-cpu interrupt handler, for example... Using a 32bit access fixes the issue for good. Cc: Matthew Leach <matthew.leach@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-09-03arm64: mm: permit use of tagged pointers at EL0Will Deacon
TCR.TBI0 can be used to cause hardware address translation to ignore the top byte of userspace virtual addresses. Whilst not especially useful in standard C programs, this can be used by JITs to `tag' pointers with various pieces of metadata. This patch enables this bit for AArch64 Linux, and adds a new file to Documentation/arm64/ which describes some potential caveats when using tagged virtual addresses. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-08-22arm64: Enable interrupts in the EL0 undef handlerCatalin Marinas
do_undefinstr() has to be called with interrupts disabled since it may read the instruction from the user address space which could lead to a data abort and subsequent might_sleep() warning in do_page_fault(). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-07-26arm64: Change kernel stack size to 16KFeng Kan
Written by Catalin Marinas, tested by APM on storm platform. This is needed because of the failures encountered when running SpecWeb benchmark test. Signed-off-by: Feng Kan <fkan@apm.com> Acked-by: Kumar Sankaran <ksankaran@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-05-31arm64: treat unhandled compat el0 traps as undefMark Rutland
Currently, if a compat process reads or writes from/to a disabled cp15/cp14 register, the trap is not handled by the el0_sync_compat handler, and the kernel will head to bad_mode, where it will die(), and oops(). For 64 bit processes, disabled system register accesses are currently treated as unhandled instructions. This patch modifies entry.S to treat these unhandled traps as undefined instructions, sending a SIGILL to userspace. This gives processes a chance to handle this and stop using inaccessible registers, and prevents further issues in the kernel as a result of the die(). Reported-by: Johannes Jensen <Johannes.Jensen@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-04-17arm64: add explicit symbols to ESR_EL1 decodingMarc Zyngier
The ESR_EL1 decoding process is a bit cryptic, and KVM has also a need for the same constants. Add a new esr.h file containing the appropriate exception classes constants, and change entry.S to use it. Fix a small bug in the EL1 breakpoint check while we're at it. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-02-14arm64: switch to generic sigaltstackAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-05arm64: move vector entry macro to assembler.hMarc Zyngier
This macro is also useful to other bits defining vectors (hypervisor stub, KVM...). Move it to a common location. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-10-22arm64: get rid of fork/vfork/clone wrappersAl Viro
[fixes from Catalin Marinas folded] Acked-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-17arm64: Use generic sys_execve() implementationCatalin Marinas
This patch converts the arm64 port to use the generic sys_execve() implementation removing the arm64-specific (compat_)sys_execve_wrapper() functions. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-10-17arm64: Use generic kernel_execve() implementationCatalin Marinas
This patch enables CONFIG_GENERIC_KERNEL_EXECVE on arm64 and removes the arm64-specific implementation of kernel_execve(). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-10-17arm64: Use generic kernel_thread() implementationCatalin Marinas
This patch enables CONFIG_GENERIC_KERNEL_THREAD on arm64, changes copy_threads to cope with kernel threads creation and adapts ret_from_fork accordingly. The arm64-specific kernel_thread implementation is no longer needed. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-10-11arm64: Do not include asm/unistd32.h in asm/unistd.hCatalin Marinas
This patch only includes asm/unistd32.h where necessary and removes its inclusion in the asm/unistd.h file. The __SYSCALL_COMPAT guard is dropped. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Will Deacon <will.deacon@arm.com>
2012-10-08arm64: Enable interrupts before calling do_notify_resume()Catalin Marinas
task_work_run() implementation had the side effect of enabling interrupts. With commit ac3d0da8 (task_work: Make task_work_add() lockless), interrupts are no longer enabled revealing the bug in the arch code. This patch enables the interrupt explicitly before calling do_notify_resume(). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-09-17arm64: Exception handlingCatalin Marinas
The patch contains the exception entry code (kernel/entry.S), pt_regs structure and related accessors, undefined instruction trapping and stack tracing. AArch64 Linux kernel (including kernel threads) runs in EL1 mode using the SP1 stack. The vectors don't have a fixed address, only alignment (2^11) requirements. 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> Acked-by: Arnd Bergmann <arnd@arndb.de>