d8ed45c5dc
This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
94 lines
2.1 KiB
C
94 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* arch/sh/kernel/vsyscall/vsyscall.c
|
|
*
|
|
* Copyright (C) 2006 Paul Mundt
|
|
*
|
|
* vDSO randomization
|
|
* Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar
|
|
*/
|
|
#include <linux/mm.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/module.h>
|
|
#include <linux/elf.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/err.h>
|
|
|
|
/*
|
|
* Should the kernel map a VDSO page into processes and pass its
|
|
* address down to glibc upon exec()?
|
|
*/
|
|
unsigned int __read_mostly vdso_enabled = 1;
|
|
EXPORT_SYMBOL_GPL(vdso_enabled);
|
|
|
|
static int __init vdso_setup(char *s)
|
|
{
|
|
vdso_enabled = simple_strtoul(s, NULL, 0);
|
|
return 1;
|
|
}
|
|
__setup("vdso=", vdso_setup);
|
|
|
|
/*
|
|
* These symbols are defined by vsyscall.o to mark the bounds
|
|
* of the ELF DSO images included therein.
|
|
*/
|
|
extern const char vsyscall_trapa_start, vsyscall_trapa_end;
|
|
static struct page *syscall_pages[1];
|
|
|
|
int __init vsyscall_init(void)
|
|
{
|
|
void *syscall_page = (void *)get_zeroed_page(GFP_ATOMIC);
|
|
syscall_pages[0] = virt_to_page(syscall_page);
|
|
|
|
/*
|
|
* XXX: Map this page to a fixmap entry if we get around
|
|
* to adding the page to ELF core dumps
|
|
*/
|
|
|
|
memcpy(syscall_page,
|
|
&vsyscall_trapa_start,
|
|
&vsyscall_trapa_end - &vsyscall_trapa_start);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Setup a VMA at program startup for the vsyscall page */
|
|
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
|
|
{
|
|
struct mm_struct *mm = current->mm;
|
|
unsigned long addr;
|
|
int ret;
|
|
|
|
if (mmap_write_lock_killable(mm))
|
|
return -EINTR;
|
|
|
|
addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
|
|
if (IS_ERR_VALUE(addr)) {
|
|
ret = addr;
|
|
goto up_fail;
|
|
}
|
|
|
|
ret = install_special_mapping(mm, addr, PAGE_SIZE,
|
|
VM_READ | VM_EXEC |
|
|
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
|
|
syscall_pages);
|
|
if (unlikely(ret))
|
|
goto up_fail;
|
|
|
|
current->mm->context.vdso = (void *)addr;
|
|
|
|
up_fail:
|
|
mmap_write_unlock(mm);
|
|
return ret;
|
|
}
|
|
|
|
const char *arch_vma_name(struct vm_area_struct *vma)
|
|
{
|
|
if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
|
|
return "[vdso]";
|
|
|
|
return NULL;
|
|
}
|