kernel-fxtec-pro1x/arch/parisc/kernel/sys_parisc.c
Helge Deller 042d27acb6 parisc,metag: Do not hardcode maximum userspace stack size
This patch affects only architectures where the stack grows upwards
(currently parisc and metag only). On those do not hardcode the maximum
initial stack size to 1GB for 32-bit processes, but make it configurable
via a config option.

The main problem with the hardcoded stack size is, that we have two
memory regions which grow upwards: stack and heap. To keep most of the
memory available for heap in a flexmap memory layout, it makes no sense
to hard allocate up to 1GB of the memory for stack which can't be used
as heap then.

This patch makes the stack size for 32-bit processes configurable and
uses 80MB as default value which has been in use during the last few
years on parisc and which hasn't showed any problems yet.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: linux-parisc@vger.kernel.org
Cc: linux-metag@vger.kernel.org
Cc: John David Anglin <dave.anglin@bell.net>
2014-05-15 00:01:41 +01:00

391 lines
10 KiB
C

/*
* PARISC specific syscalls
*
* Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
* Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
* Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
* Copyright (C) 1999-2014 Helge Deller <deller@gmx.de>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <asm/uaccess.h>
#include <asm/elf.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/linkage.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/shm.h>
#include <linux/syscalls.h>
#include <linux/utsname.h>
#include <linux/personality.h>
#include <linux/random.h>
/* we construct an artificial offset for the mapping based on the physical
* address of the kernel mapping variable */
#define GET_LAST_MMAP(filp) \
(filp ? ((unsigned long) filp->f_mapping) >> 8 : 0UL)
#define SET_LAST_MMAP(filp, val) \
{ /* nothing */ }
static int get_offset(unsigned int last_mmap)
{
return (last_mmap & (SHM_COLOUR-1)) >> PAGE_SHIFT;
}
static unsigned long shared_align_offset(unsigned int last_mmap,
unsigned long pgoff)
{
return (get_offset(last_mmap) + pgoff) << PAGE_SHIFT;
}
static inline unsigned long COLOR_ALIGN(unsigned long addr,
unsigned int last_mmap, unsigned long pgoff)
{
unsigned long base = (addr+SHM_COLOUR-1) & ~(SHM_COLOUR-1);
unsigned long off = (SHM_COLOUR-1) &
(shared_align_offset(last_mmap, pgoff) << PAGE_SHIFT);
return base + off;
}
/*
* Top of mmap area (just below the process stack).
*/
static unsigned long mmap_upper_limit(void)
{
unsigned long stack_base;
/* Limit stack size - see setup_arg_pages() in fs/exec.c */
stack_base = rlimit_max(RLIMIT_STACK);
if (stack_base > STACK_SIZE_MAX)
stack_base = STACK_SIZE_MAX;
return PAGE_ALIGN(STACK_TOP - stack_base);
}
unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long task_size = TASK_SIZE;
int do_color_align, last_mmap;
struct vm_unmapped_area_info info;
if (len > task_size)
return -ENOMEM;
do_color_align = 0;
if (filp || (flags & MAP_SHARED))
do_color_align = 1;
last_mmap = GET_LAST_MMAP(filp);
if (flags & MAP_FIXED) {
if ((flags & MAP_SHARED) && last_mmap &&
(addr - shared_align_offset(last_mmap, pgoff))
& (SHM_COLOUR - 1))
return -EINVAL;
goto found_addr;
}
if (addr) {
if (do_color_align && last_mmap)
addr = COLOR_ALIGN(addr, last_mmap, pgoff);
else
addr = PAGE_ALIGN(addr);
vma = find_vma(mm, addr);
if (task_size - len >= addr &&
(!vma || addr + len <= vma->vm_start))
goto found_addr;
}
info.flags = 0;
info.length = len;
info.low_limit = mm->mmap_legacy_base;
info.high_limit = mmap_upper_limit();
info.align_mask = last_mmap ? (PAGE_MASK & (SHM_COLOUR - 1)) : 0;
info.align_offset = shared_align_offset(last_mmap, pgoff);
addr = vm_unmapped_area(&info);
found_addr:
if (do_color_align && !last_mmap && !(addr & ~PAGE_MASK))
SET_LAST_MMAP(filp, addr - (pgoff << PAGE_SHIFT));
return addr;
}
unsigned long
arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
const unsigned long len, const unsigned long pgoff,
const unsigned long flags)
{
struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
unsigned long addr = addr0;
int do_color_align, last_mmap;
struct vm_unmapped_area_info info;
#ifdef CONFIG_64BIT
/* This should only ever run for 32-bit processes. */
BUG_ON(!test_thread_flag(TIF_32BIT));
#endif
/* requested length too big for entire address space */
if (len > TASK_SIZE)
return -ENOMEM;
do_color_align = 0;
if (filp || (flags & MAP_SHARED))
do_color_align = 1;
last_mmap = GET_LAST_MMAP(filp);
if (flags & MAP_FIXED) {
if ((flags & MAP_SHARED) && last_mmap &&
(addr - shared_align_offset(last_mmap, pgoff))
& (SHM_COLOUR - 1))
return -EINVAL;
goto found_addr;
}
/* requesting a specific address */
if (addr) {
if (do_color_align && last_mmap)
addr = COLOR_ALIGN(addr, last_mmap, pgoff);
else
addr = PAGE_ALIGN(addr);
vma = find_vma(mm, addr);
if (TASK_SIZE - len >= addr &&
(!vma || addr + len <= vma->vm_start))
goto found_addr;
}
info.flags = VM_UNMAPPED_AREA_TOPDOWN;
info.length = len;
info.low_limit = PAGE_SIZE;
info.high_limit = mm->mmap_base;
info.align_mask = last_mmap ? (PAGE_MASK & (SHM_COLOUR - 1)) : 0;
info.align_offset = shared_align_offset(last_mmap, pgoff);
addr = vm_unmapped_area(&info);
if (!(addr & ~PAGE_MASK))
goto found_addr;
VM_BUG_ON(addr != -ENOMEM);
/*
* A failed mmap() very likely causes application failure,
* so fall back to the bottom-up function here. This scenario
* can happen with large stack limits and large mmap()
* allocations.
*/
return arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
found_addr:
if (do_color_align && !last_mmap && !(addr & ~PAGE_MASK))
SET_LAST_MMAP(filp, addr - (pgoff << PAGE_SHIFT));
return addr;
}
static int mmap_is_legacy(void)
{
if (current->personality & ADDR_COMPAT_LAYOUT)
return 1;
/* parisc stack always grows up - so a unlimited stack should
* not be an indicator to use the legacy memory layout.
* if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
* return 1;
*/
return sysctl_legacy_va_layout;
}
static unsigned long mmap_rnd(void)
{
unsigned long rnd = 0;
/*
* 8 bits of randomness in 32bit mmaps, 20 address space bits
* 28 bits of randomness in 64bit mmaps, 40 address space bits
*/
if (current->flags & PF_RANDOMIZE) {
if (is_32bit_task())
rnd = get_random_int() % (1<<8);
else
rnd = get_random_int() % (1<<28);
}
return rnd << PAGE_SHIFT;
}
static unsigned long mmap_legacy_base(void)
{
return TASK_UNMAPPED_BASE + mmap_rnd();
}
/*
* This function, called very early during the creation of a new
* process VM image, sets up which VM layout function to use:
*/
void arch_pick_mmap_layout(struct mm_struct *mm)
{
mm->mmap_legacy_base = mmap_legacy_base();
mm->mmap_base = mmap_upper_limit();
if (mmap_is_legacy()) {
mm->mmap_base = mm->mmap_legacy_base;
mm->get_unmapped_area = arch_get_unmapped_area;
} else {
mm->get_unmapped_area = arch_get_unmapped_area_topdown;
}
}
asmlinkage unsigned long sys_mmap2(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags, unsigned long fd,
unsigned long pgoff)
{
/* Make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE
we have. */
return sys_mmap_pgoff(addr, len, prot, flags, fd,
pgoff >> (PAGE_SHIFT - 12));
}
asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags, unsigned long fd,
unsigned long offset)
{
if (!(offset & ~PAGE_MASK)) {
return sys_mmap_pgoff(addr, len, prot, flags, fd,
offset >> PAGE_SHIFT);
} else {
return -EINVAL;
}
}
/* Fucking broken ABI */
#ifdef CONFIG_64BIT
asmlinkage long parisc_truncate64(const char __user * path,
unsigned int high, unsigned int low)
{
return sys_truncate(path, (long)high << 32 | low);
}
asmlinkage long parisc_ftruncate64(unsigned int fd,
unsigned int high, unsigned int low)
{
return sys_ftruncate(fd, (long)high << 32 | low);
}
/* stubs for the benefit of the syscall_table since truncate64 and truncate
* are identical on LP64 */
asmlinkage long sys_truncate64(const char __user * path, unsigned long length)
{
return sys_truncate(path, length);
}
asmlinkage long sys_ftruncate64(unsigned int fd, unsigned long length)
{
return sys_ftruncate(fd, length);
}
asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg)
{
return sys_fcntl(fd, cmd, arg);
}
#else
asmlinkage long parisc_truncate64(const char __user * path,
unsigned int high, unsigned int low)
{
return sys_truncate64(path, (loff_t)high << 32 | low);
}
asmlinkage long parisc_ftruncate64(unsigned int fd,
unsigned int high, unsigned int low)
{
return sys_ftruncate64(fd, (loff_t)high << 32 | low);
}
#endif
asmlinkage ssize_t parisc_pread64(unsigned int fd, char __user *buf, size_t count,
unsigned int high, unsigned int low)
{
return sys_pread64(fd, buf, count, (loff_t)high << 32 | low);
}
asmlinkage ssize_t parisc_pwrite64(unsigned int fd, const char __user *buf,
size_t count, unsigned int high, unsigned int low)
{
return sys_pwrite64(fd, buf, count, (loff_t)high << 32 | low);
}
asmlinkage ssize_t parisc_readahead(int fd, unsigned int high, unsigned int low,
size_t count)
{
return sys_readahead(fd, (loff_t)high << 32 | low, count);
}
asmlinkage long parisc_fadvise64_64(int fd,
unsigned int high_off, unsigned int low_off,
unsigned int high_len, unsigned int low_len, int advice)
{
return sys_fadvise64_64(fd, (loff_t)high_off << 32 | low_off,
(loff_t)high_len << 32 | low_len, advice);
}
asmlinkage long parisc_sync_file_range(int fd,
u32 hi_off, u32 lo_off, u32 hi_nbytes, u32 lo_nbytes,
unsigned int flags)
{
return sys_sync_file_range(fd, (loff_t)hi_off << 32 | lo_off,
(loff_t)hi_nbytes << 32 | lo_nbytes, flags);
}
asmlinkage long parisc_fallocate(int fd, int mode, u32 offhi, u32 offlo,
u32 lenhi, u32 lenlo)
{
return sys_fallocate(fd, mode, ((u64)offhi << 32) | offlo,
((u64)lenhi << 32) | lenlo);
}
asmlinkage unsigned long sys_alloc_hugepages(int key, unsigned long addr, unsigned long len, int prot, int flag)
{
return -ENOMEM;
}
asmlinkage int sys_free_hugepages(unsigned long addr)
{
return -EINVAL;
}
long parisc_personality(unsigned long personality)
{
long err;
if (personality(current->personality) == PER_LINUX32
&& personality(personality) == PER_LINUX)
personality = (personality & ~PER_MASK) | PER_LINUX32;
err = sys_personality(personality);
if (personality(err) == PER_LINUX32)
err = (err & ~PER_MASK) | PER_LINUX;
return err;
}