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dec20c50df
Arch-specific implementations of syscall handlers are currently used over generic implementations for the following reasons: 1. Semantics unique to powerpc 2. Compatibility syscalls require 'argument padding' to comply with 64-bit argument convention in ELF32 abi. 3. Parameter types or order is different in other architectures. These syscall handlers have been defined prior to this patch series without invoking the SYSCALL_DEFINE or COMPAT_SYSCALL_DEFINE macros with custom input and output types. We remove every such direct definition in favour of the aforementioned macros. Also update syscalls.tbl in order to refer to the symbol names generated by each of these macros. Since ppc64_personality can be called by both 64 bit and 32 bit binaries through compatibility, we must generate both both compat_sys_ and sys_ symbols for this handler. As an aside: A number of architectures including arm and powerpc agree on an alternative argument order and numbering for most of these arch-specific handlers. A future patch series may allow for asm/unistd.h to signal through its defines that a generic implementation of these syscall handlers with the correct calling convention be emitted, through the __ARCH_WANT_COMPAT_SYS_... convention. Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220921065605.1051927-16-rmclure@linux.ibm.com
127 lines
3.3 KiB
C
127 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Implementation of various system calls for Linux/PowerPC
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*
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Derived from "arch/i386/kernel/sys_i386.c"
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* Adapted from the i386 version by Gary Thomas
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* Modified by Cort Dougan (cort@cs.nmt.edu)
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* and Paul Mackerras (paulus@cs.anu.edu.au).
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*
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* This file contains various random system calls that
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* have a non-standard calling sequence on the Linux/PPC
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* platform.
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*/
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/syscalls.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/smp.h>
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#include <linux/sem.h>
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#include <linux/msg.h>
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#include <linux/shm.h>
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#include <linux/stat.h>
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#include <linux/mman.h>
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#include <linux/sys.h>
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#include <linux/ipc.h>
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#include <linux/utsname.h>
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#include <linux/file.h>
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#include <linux/personality.h>
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#include <linux/uaccess.h>
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#include <asm/syscalls.h>
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#include <asm/time.h>
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#include <asm/unistd.h>
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static long do_mmap2(unsigned long addr, size_t len,
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unsigned long prot, unsigned long flags,
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unsigned long fd, unsigned long off, int shift)
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{
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if (!arch_validate_prot(prot, addr))
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return -EINVAL;
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if (!IS_ALIGNED(off, 1 << shift))
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return -EINVAL;
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return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> shift);
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}
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SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
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unsigned long, prot, unsigned long, flags,
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unsigned long, fd, unsigned long, pgoff)
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{
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return do_mmap2(addr, len, prot, flags, fd, pgoff, PAGE_SHIFT-12);
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}
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#ifdef CONFIG_COMPAT
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COMPAT_SYSCALL_DEFINE6(mmap2,
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unsigned long, addr, size_t, len,
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unsigned long, prot, unsigned long, flags,
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unsigned long, fd, unsigned long, off_4k)
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{
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return do_mmap2(addr, len, prot, flags, fd, off_4k, PAGE_SHIFT-12);
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}
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#endif
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SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
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unsigned long, prot, unsigned long, flags,
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unsigned long, fd, off_t, offset)
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{
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return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT);
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}
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#ifdef CONFIG_PPC64
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static long do_ppc64_personality(unsigned long personality)
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{
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long ret;
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if (personality(current->personality) == PER_LINUX32
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&& personality(personality) == PER_LINUX)
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personality = (personality & ~PER_MASK) | PER_LINUX32;
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ret = ksys_personality(personality);
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if (personality(ret) == PER_LINUX32)
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ret = (ret & ~PER_MASK) | PER_LINUX;
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return ret;
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}
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SYSCALL_DEFINE1(ppc64_personality, unsigned long, personality)
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{
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return do_ppc64_personality(personality);
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}
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#ifdef CONFIG_COMPAT
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COMPAT_SYSCALL_DEFINE1(ppc64_personality, unsigned long, personality)
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{
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return do_ppc64_personality(personality);
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}
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#endif /* CONFIG_COMPAT */
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#endif /* CONFIG_PPC64 */
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SYSCALL_DEFINE6(ppc_fadvise64_64,
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int, fd, int, advice, u32, offset_high, u32, offset_low,
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u32, len_high, u32, len_low)
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{
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return ksys_fadvise64_64(fd, merge_64(offset_high, offset_low),
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merge_64(len_high, len_low), advice);
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}
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SYSCALL_DEFINE0(switch_endian)
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{
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struct thread_info *ti;
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regs_set_return_msr(current->thread.regs,
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current->thread.regs->msr ^ MSR_LE);
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/*
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* Set TIF_RESTOREALL so that r3 isn't clobbered on return to
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* userspace. That also has the effect of restoring the non-volatile
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* GPRs, so we saved them on the way in here.
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*/
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ti = current_thread_info();
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ti->flags |= _TIF_RESTOREALL;
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return 0;
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}
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