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* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 452Thomas Gleixner2019-06-191-12/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software void 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 distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http void www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 1 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081201.003433009@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* arm64: use the correct function type for __arm64_sys_ni_syscallSami Tolvanen2019-05-291-5/+2
| | | | | | | | | | Calling sys_ni_syscall through a syscall_fn_t pointer trips indirect call Control-Flow Integrity checking due to a function type mismatch. Use SYSCALL_DEFINE0 for __arm64_sys_ni_syscall instead and remove the now unnecessary casts. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: implement syscall wrappersMark Rutland2018-07-121-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To minimize the risk of userspace-controlled values being used under speculation, this patch adds pt_regs based syscall wrappers for arm64, which pass the minimum set of required userspace values to syscall implementations. For each syscall, a wrapper which takes a pt_regs argument is automatically generated, and this extracts the arguments before calling the "real" syscall implementation. Each syscall has three functions generated: * __do_<compat_>sys_<name> is the "real" syscall implementation, with the expected prototype. * __se_<compat_>sys_<name> is the sign-extension/narrowing wrapper, inherited from common code. This takes a series of long parameters, casting each to the requisite types required by the "real" syscall implementation in __do_<compat_>sys_<name>. This wrapper *may* not be necessary on arm64 given the AAPCS rules on unused register bits, but it seemed safer to keep the wrapper for now. * __arm64_<compat_>_sys_<name> takes a struct pt_regs pointer, and extracts *only* the relevant register values, passing these on to the __se_<compat_>sys_<name> wrapper. The syscall invocation code is updated to handle the calling convention required by __arm64_<compat_>_sys_<name>, and passes a single struct pt_regs pointer. The compiler can fold the syscall implementation and its wrappers, such that the overhead of this approach is minimized. Note that we play games with sys_ni_syscall(). It can't be defined with SYSCALL_DEFINE0() because we must avoid the possibility of error injection. Additionally, there are a couple of locations where we need to call it from C code, and we don't (currently) have a ksys_ni_syscall(). While it has no wrapper, passing in a redundant pt_regs pointer is benign per the AAPCS. When ARCH_HAS_SYSCALL_WRAPPER is selected, no prototype is defines for sys_ni_syscall(). Since we need to treat it differently for in-kernel calls and the syscall tables, the prototype is defined as-required. The wrappers are largely the same as their x86 counterparts, but simplified as we don't have a variety of compat calling conventions that require separate stubs. Unlike x86, we have some zero-argument compat syscalls, and must define COMPAT_SYSCALL_DEFINE0() to ensure that these are also given an __arm64_compat_sys_ prefix. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: convert compat wrappers to CMark Rutland2018-07-121-11/+103
| | | | | | | | | | | | | | | | | | | | | | | In preparation for converting to pt_regs syscall wrappers, convert our existing compat wrappers to C. This will allow the pt_regs wrappers to be automatically generated, and will allow for the compat register manipulation to be folded in with the pt_regs accesses. To avoid confusion with the upcoming pt_regs wrappers and existing compat wrappers provided by core code, the C wrappers are renamed to compat_sys_aarch32_<syscall>. With the assembly wrappers gone, we can get rid of entry32.S and the associated boilerplate. Note that these must call the ksys_* syscall entry points, as the usual sys_* entry points will be modified to take a single pt_regs pointer argument. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: drop alignment from syscall tablesMark Rutland2018-07-121-5/+1
| | | | | | | | | | | | | | | Our syscall tables are aligned to 4096 bytes, which allowed their addresses to be generated with a single adrp in entry.S. This has the unfortunate property of wasting space in .rodata for the necessary padding. Now that the address is generated by C code, we can rely on the compiler to do the right thing, and drop the alignemnt. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: introduce syscall_fn_tMark Rutland2018-07-121-3/+5
| | | | | | | | | | | | | In preparation for invoking arbitrary syscalls from C code, let's define a type for an arbitrary syscall, matching the parameter passing rules of the AAPCS. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: remove sigreturn wrappersMark Rutland2018-07-121-2/+2
| | | | | | | | | | | | | | | | | | | | | | | The arm64 sigreturn* syscall handlers are non-standard. Rather than taking a number of user parameters in registers as per the AAPCS, they expect the pt_regs as their sole argument. To make this work, we override the syscall definitions to invoke wrappers written in assembly, which mov the SP into x0, and branch to their respective C functions. On other architectures (such as x86), the sigreturn* functions take no argument and instead use current_pt_regs() to acquire the user registers. This requires less boilerplate code, and allows for other features such as interposing C code in this path. This patch takes the same approach for arm64. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Tentatively-reviewed-by: Dave Martin <dave.martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: fix implementation of mmap2 compat syscallAndreas Schwab2015-03-191-0/+1
| | | | | | | | | | The arm mmap2 syscall takes the offset in units of 4K, thus with 64K pages the offset needs to be scaled to units of pages. Signed-off-by: Andreas Schwab <schwab@suse.de> Signed-off-by: Alexander Graf <agraf@suse.de> [will: removed redundant lr parameter, localised PAGE_SHIFT #if check] Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: Implement the compat_sys_call_table in CCatalin Marinas2015-01-271-0/+51
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>