linux/arch/arc/include/asm/page.h
Vineet Gupta 93312b6da4 ARC: mm: allow mprotect to make stack mappings executable
mprotect(EXEC) was failing for stack mappings as default vm flags was
missing MAYEXEC.

This was triggered by glibc test suite nptl/tst-execstack testcase

What is surprising is that despite running LTP for years on, we didn't
catch this issue as it lacks a directed test case.

gcc dejagnu tests with nested functions also requiring exec stack work
fine though because they rely on the GNU_STACK segment spit out by
compiler and handled in kernel elf loader.

This glibc case is different as the stack is non exec to begin with and
a dlopen of shared lib with GNU_STACK segment triggers the exec stack
proceedings using a mprotect(PROT_EXEC) which was broken.

CC: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2018-07-11 11:03:06 -07:00

118 lines
2.9 KiB
C

/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_ARC_PAGE_H
#define __ASM_ARC_PAGE_H
#include <uapi/asm/page.h>
#ifndef __ASSEMBLY__
#define clear_page(paddr) memset((paddr), 0, PAGE_SIZE)
#define copy_page(to, from) memcpy((to), (from), PAGE_SIZE)
struct vm_area_struct;
struct page;
#define __HAVE_ARCH_COPY_USER_HIGHPAGE
void copy_user_highpage(struct page *to, struct page *from,
unsigned long u_vaddr, struct vm_area_struct *vma);
void clear_user_page(void *to, unsigned long u_vaddr, struct page *page);
#undef STRICT_MM_TYPECHECKS
#ifdef STRICT_MM_TYPECHECKS
/*
* These are used to make use of C type-checking..
*/
typedef struct {
#ifdef CONFIG_ARC_HAS_PAE40
unsigned long long pte;
#else
unsigned long pte;
#endif
} pte_t;
typedef struct {
unsigned long pgd;
} pgd_t;
typedef struct {
unsigned long pgprot;
} pgprot_t;
#define pte_val(x) ((x).pte)
#define pgd_val(x) ((x).pgd)
#define pgprot_val(x) ((x).pgprot)
#define __pte(x) ((pte_t) { (x) })
#define __pgd(x) ((pgd_t) { (x) })
#define __pgprot(x) ((pgprot_t) { (x) })
#define pte_pgprot(x) __pgprot(pte_val(x))
#else /* !STRICT_MM_TYPECHECKS */
#ifdef CONFIG_ARC_HAS_PAE40
typedef unsigned long long pte_t;
#else
typedef unsigned long pte_t;
#endif
typedef unsigned long pgd_t;
typedef unsigned long pgprot_t;
#define pte_val(x) (x)
#define pgd_val(x) (x)
#define pgprot_val(x) (x)
#define __pte(x) (x)
#define __pgd(x) (x)
#define __pgprot(x) (x)
#define pte_pgprot(x) (x)
#endif
typedef pte_t * pgtable_t;
/*
* Use virt_to_pfn with caution:
* If used in pte or paddr related macros, it could cause truncation
* in PAE40 builds
* As a rule of thumb, only use it in helpers starting with virt_
* You have been warned !
*/
#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
#define ARCH_PFN_OFFSET virt_to_pfn(CONFIG_LINUX_RAM_BASE)
#ifdef CONFIG_FLATMEM
#define pfn_valid(pfn) (((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
#endif
/*
* __pa, __va, virt_to_page (ALERT: deprecated, don't use them)
*
* These macros have historically been misnamed
* virt here means link-address/program-address as embedded in object code.
* And for ARC, link-addr = physical address
*/
#define __pa(vaddr) ((unsigned long)(vaddr))
#define __va(paddr) ((void *)((unsigned long)(paddr)))
#define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr))
#define virt_addr_valid(kaddr) pfn_valid(virt_to_pfn(kaddr))
/* Default Permissions for stack/heaps pages (Non Executable) */
#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#define WANT_PAGE_VIRTUAL 1
#include <asm-generic/memory_model.h> /* page_to_pfn, pfn_to_page */
#include <asm-generic/getorder.h>
#endif /* !__ASSEMBLY__ */
#endif