linux/arch/xtensa/kernel/syscall.c
Matthew Wilcox (Oracle) 49c40fb4b8 xtensa: remove vma linked list walks
Use the VMA iterator instead.  Since VMA can no longer be NULL in the
loop, then deal with out-of-memory outside the loop.  This means a
slightly longer run time in the failure case (-ENOMEM) - it will run to
the end of the VMAs before erroring instead of in the middle of the loop.

Link: https://lkml.kernel.org/r/20220906194824.2110408-37-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:20 -07:00

100 lines
2.4 KiB
C

/*
* arch/xtensa/kernel/syscall.c
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2005 Tensilica Inc.
* Copyright (C) 2000 Silicon Graphics, Inc.
* Copyright (C) 1995 - 2000 by Ralf Baechle
*
* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
* Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca>
* Chris Zankel <chris@zankel.net>
* Kevin Chea
*
*/
#include <linux/uaccess.h>
#include <asm/syscall.h>
#include <linux/linkage.h>
#include <linux/stringify.h>
#include <linux/errno.h>
#include <linux/syscalls.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/mman.h>
#include <linux/sched/mm.h>
#include <linux/shm.h>
syscall_t sys_call_table[] /* FIXME __cacheline_aligned */= {
#define __SYSCALL(nr, entry) (syscall_t)entry,
#include <asm/syscall_table.h>
};
#define COLOUR_ALIGN(addr, pgoff) \
((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \
(((pgoff) << PAGE_SHIFT) & (SHMLBA - 1)))
asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg)
{
unsigned long ret;
long err;
err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
if (err)
return err;
return (long)ret;
}
asmlinkage long xtensa_fadvise64_64(int fd, int advice,
unsigned long long offset, unsigned long long len)
{
return ksys_fadvise64_64(fd, offset, len, advice);
}
#ifdef CONFIG_MMU
unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct vm_area_struct *vmm;
struct vma_iterator vmi;
if (flags & MAP_FIXED) {
/* We do not accept a shared mapping if it would violate
* cache aliasing constraints.
*/
if ((flags & MAP_SHARED) &&
((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
return -EINVAL;
return addr;
}
if (len > TASK_SIZE)
return -ENOMEM;
if (!addr)
addr = TASK_UNMAPPED_BASE;
if (flags & MAP_SHARED)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
vma_iter_init(&vmi, current->mm, addr);
for_each_vma(vmi, vmm) {
/* At this point: (addr < vmm->vm_end). */
if (addr + len <= vm_start_gap(vmm))
break;
addr = vmm->vm_end;
if (flags & MAP_SHARED)
addr = COLOUR_ALIGN(addr, pgoff);
}
if (TASK_SIZE - len < addr)
return -ENOMEM;
return addr;
}
#endif