Files
kernel_arpi/arch/powerpc/kernel/syscalls.c
Rohan McLure 592b302d8b powerpc: Fix fallocate and fadvise64_64 compat parameter combination
[ Upstream commit 016ff72bd2090903715c0f9422a44afbb966f4ee ]

As reported[1] by Arnd, the arch-specific fadvise64_64 and fallocate
compatibility handlers assume parameters are passed with 32-bit
big-endian ABI. This affects the assignment of odd-even parameter pairs
to the high or low words of a 64-bit syscall parameter.

Fix fadvise64_64 fallocate compat handlers to correctly swap upper/lower
32 bits conditioned on endianness.

A future patch will replace the arch-specific compat fallocate with an
asm-generic implementation. This patch is intended for ease of
back-port.

[1]: https://lore.kernel.org/all/be29926f-226e-48dc-871a-e29a54e80583@www.fastmail.com/

Fixes: 57f48b4b74 ("powerpc/compat_sys: swap hi/lo parts of 64-bit syscall args in LE mode")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-9-rmclure@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 12:35:22 +02:00

123 lines
3.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Implementation of various system calls for Linux/PowerPC
*
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Derived from "arch/i386/kernel/sys_i386.c"
* Adapted from the i386 version by Gary Thomas
* Modified by Cort Dougan (cort@cs.nmt.edu)
* and Paul Mackerras (paulus@cs.anu.edu.au).
*
* This file contains various random system calls that
* have a non-standard calling sequence on the Linux/PPC
* platform.
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/syscalls.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/mman.h>
#include <linux/sys.h>
#include <linux/ipc.h>
#include <linux/utsname.h>
#include <linux/file.h>
#include <linux/personality.h>
#include <linux/uaccess.h>
#include <asm/syscalls.h>
#include <asm/time.h>
#include <asm/unistd.h>
#include <asm/asm-prototypes.h>
static inline long do_mmap2(unsigned long addr, size_t len,
unsigned long prot, unsigned long flags,
unsigned long fd, unsigned long off, int shift)
{
if (!arch_validate_prot(prot, addr))
return -EINVAL;
if (!IS_ALIGNED(off, 1 << shift))
return -EINVAL;
return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> shift);
}
SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
unsigned long, prot, unsigned long, flags,
unsigned long, fd, unsigned long, pgoff)
{
return do_mmap2(addr, len, prot, flags, fd, pgoff, PAGE_SHIFT-12);
}
SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
unsigned long, prot, unsigned long, flags,
unsigned long, fd, off_t, offset)
{
return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT);
}
#ifdef CONFIG_PPC32
/*
* Due to some executables calling the wrong select we sometimes
* get wrong args. This determines how the args are being passed
* (a single ptr to them all args passed) then calls
* sys_select() with the appropriate args. -- Cort
*/
int
ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct __kernel_old_timeval __user *tvp)
{
if ( (unsigned long)n >= 4096 )
return sys_old_select((void __user *)n);
return sys_select(n, inp, outp, exp, tvp);
}
#endif
#ifdef CONFIG_PPC64
long ppc64_personality(unsigned long personality)
{
long ret;
if (personality(current->personality) == PER_LINUX32
&& personality(personality) == PER_LINUX)
personality = (personality & ~PER_MASK) | PER_LINUX32;
ret = sys_personality(personality);
if (personality(ret) == PER_LINUX32)
ret = (ret & ~PER_MASK) | PER_LINUX;
return ret;
}
#endif
long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
u32 len_high, u32 len_low)
{
return ksys_fadvise64_64(fd, merge_64(offset_high, offset_low),
merge_64(len_high, len_low), advice);
}
SYSCALL_DEFINE0(switch_endian)
{
struct thread_info *ti;
regs_set_return_msr(current->thread.regs,
current->thread.regs->msr ^ MSR_LE);
/*
* Set TIF_RESTOREALL so that r3 isn't clobbered on return to
* userspace. That also has the effect of restoring the non-volatile
* GPRs, so we saved them on the way in here.
*/
ti = current_thread_info();
ti->flags |= _TIF_RESTOREALL;
return 0;
}