linux_dsm_epyc7002/arch/s390/kernel/sys_s390.c
Jiri Kosina 5ab37e1b22 s390: do not clobber personality flags in sys_32_personality()
There are multiple errors in how sys_32_personality() handles personality
flags stored in top three bytes.

- directly comparing current->personality against PER_LINUX32 doesn't work
  in cases when any of the personality flags stored in the top three bytes
  are used.
- directly forcefully setting personality to PER_LINUX32 or PER_LINUX
  discards any flags stored in the top three bytes

Fix the first one by properly using personality() macro to compare only
PER_MASK bytes.
Fix the second one by setting only the bits that should be set, instead of
overwriting the whole value.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-08-08 07:32:56 -07:00

151 lines
4.1 KiB
C

/*
* S390 version
* Copyright IBM Corp. 1999, 2000
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
* Thomas Spatzier (tspat@de.ibm.com)
*
* Derived from "arch/i386/kernel/sys_i386.c"
*
* This file contains various random system calls that
* have a non-standard calling sequence on the Linux/s390
* platform.
*/
#include <linux/errno.h>
#include <linux/sched.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/syscalls.h>
#include <linux/mman.h>
#include <linux/file.h>
#include <linux/utsname.h>
#include <linux/personality.h>
#include <linux/unistd.h>
#include <linux/ipc.h>
#include <asm/uaccess.h>
#include "entry.h"
/*
* Perform the mmap() system call. Linux for S/390 isn't able to handle more
* than 5 system call parameters, so this system call uses a memory block
* for parameter passing.
*/
struct s390_mmap_arg_struct {
unsigned long addr;
unsigned long len;
unsigned long prot;
unsigned long flags;
unsigned long fd;
unsigned long offset;
};
SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
{
struct s390_mmap_arg_struct a;
int error = -EFAULT;
if (copy_from_user(&a, arg, sizeof(a)))
goto out;
error = sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
out:
return error;
}
/*
* sys_ipc() is the de-multiplexer for the SysV IPC calls.
*/
SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,
unsigned long, third, void __user *, ptr)
{
if (call >> 16)
return -EINVAL;
/* The s390 sys_ipc variant has only five parameters instead of six
* like the generic variant. The only difference is the handling of
* the SEMTIMEDOP subcall where on s390 the third parameter is used
* as a pointer to a struct timespec where the generic variant uses
* the fifth parameter.
* Therefore we can call the generic variant by simply passing the
* third parameter also as fifth parameter.
*/
return sys_ipc(call, first, second, third, ptr, third);
}
#ifdef CONFIG_64BIT
SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
{
unsigned int ret;
if (personality(current->personality) == PER_LINUX32 &&
personality(personality) == PER_LINUX)
personality |= PER_LINUX32;
ret = sys_personality(personality);
if (personality(ret) == PER_LINUX32)
ret &= ~PER_LINUX32;
return ret;
}
#endif /* CONFIG_64BIT */
/*
* Wrapper function for sys_fadvise64/fadvise64_64
*/
#ifndef CONFIG_64BIT
SYSCALL_DEFINE5(s390_fadvise64, int, fd, u32, offset_high, u32, offset_low,
size_t, len, int, advice)
{
return sys_fadvise64(fd, (u64) offset_high << 32 | offset_low,
len, advice);
}
struct fadvise64_64_args {
int fd;
long long offset;
long long len;
int advice;
};
SYSCALL_DEFINE1(s390_fadvise64_64, struct fadvise64_64_args __user *, args)
{
struct fadvise64_64_args a;
if ( copy_from_user(&a, args, sizeof(a)) )
return -EFAULT;
return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
}
/*
* This is a wrapper to call sys_fallocate(). For 31 bit s390 the last
* 64 bit argument "len" is split into the upper and lower 32 bits. The
* system call wrapper in the user space loads the value to %r6/%r7.
* The code in entry.S keeps the values in %r2 - %r6 where they are and
* stores %r7 to 96(%r15). But the standard C linkage requires that
* the whole 64 bit value for len is stored on the stack and doesn't
* use %r6 at all. So s390_fallocate has to convert the arguments from
* %r2: fd, %r3: mode, %r4/%r5: offset, %r6/96(%r15)-99(%r15): len
* to
* %r2: fd, %r3: mode, %r4/%r5: offset, 96(%r15)-103(%r15): len
*/
SYSCALL_DEFINE(s390_fallocate)(int fd, int mode, loff_t offset,
u32 len_high, u32 len_low)
{
return sys_fallocate(fd, mode, offset, ((u64)len_high << 32) | len_low);
}
#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
asmlinkage long SyS_s390_fallocate(long fd, long mode, loff_t offset,
long len_high, long len_low)
{
return SYSC_s390_fallocate((int) fd, (int) mode, offset,
(u32) len_high, (u32) len_low);
}
SYSCALL_ALIAS(sys_s390_fallocate, SyS_s390_fallocate);
#endif
#endif