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Merge branch 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next

Browse Source 
Pull x86 cdso updates from Peter Anvin:
 "Vdso cleanups and improvements largely from Andy Lutomirski.  This
  makes the vdso a lot less ''special''"

* 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vdso, build: Make LE access macros clearer, host-safe
  x86/vdso, build: Fix cross-compilation from big-endian architectures
  x86/vdso, build: When vdso2c fails, unlink the output
  x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET
  x86, mm: Replace arch_vma_name with vm_ops->name for vsyscalls
  x86, mm: Improve _install_special_mapping and fix x86 vdso naming
  mm, fs: Add vm_ops->name as an alternative to arch_vma_name
  x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET
  x86, vdso: Remove vestiges of VDSO_PRELINK and some outdated comments
  x86, vdso: Move the vvar and hpet mappings next to the 64-bit vDSO
  x86, vdso: Move the 32-bit vdso special pages after the text
  x86, vdso: Reimplement vdso.so preparation in build-time C
  x86, vdso: Move syscall and sysenter setup into kernel/cpu/common.c
  x86, vdso: Clean up 32-bit vs 64-bit vdso params
  x86, mm: Ensure correct alignment of the fixmap
This commit is contained in:
Linus Torvalds 2014-06-05 08:05:29 -07:00
commit a0abcf2e8f
40 changed files with 798 additions and 612 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
arch/x86/ia32/ia32_signal.c
View File

@ -383,8 +383,8 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
} else {
/* Return stub is in 32bit vsyscall page */
if (current->mm->context.vdso)
restorer = VDSO32_SYMBOL(current->mm->context.vdso,
sigreturn);
restorer = current->mm->context.vdso +
selected_vdso32->sym___kernel_sigreturn;
else
restorer = &frame->retcode;
}
@ -462,8 +462,8 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
if (ksig->ka.sa.sa_flags & SA_RESTORER)
restorer = ksig->ka.sa.sa_restorer;
else
restorer = VDSO32_SYMBOL(current->mm->context.vdso,
rt_sigreturn);
restorer = current->mm->context.vdso +
selected_vdso32->sym___kernel_rt_sigreturn;
put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
/*

35
arch/x86/include/asm/elf.h
View File

@ -75,7 +75,12 @@ typedef struct user_fxsr_struct elf_fpxregset_t;
#include <asm/vdso.h>
extern unsigned int vdso_enabled;
#ifdef CONFIG_X86_64
extern unsigned int vdso64_enabled;
#endif
#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
extern unsigned int vdso32_enabled;
#endif
/*
* This is used to ensure we don't load something for the wrong architecture.
@ -269,9 +274,9 @@ extern int force_personality32;
struct task_struct;
#define ARCH_DLINFO_IA32(vdso_enabled) \
#define ARCH_DLINFO_IA32 \
do { \
if (vdso_enabled) { \
if (vdso32_enabled) { \
NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY); \
NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE); \
} \
@ -281,7 +286,7 @@ do { \
#define STACK_RND_MASK (0x7ff)
#define ARCH_DLINFO ARCH_DLINFO_IA32(vdso_enabled)
#define ARCH_DLINFO ARCH_DLINFO_IA32
/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
@ -292,16 +297,17 @@ do { \
#define ARCH_DLINFO \
do { \
if (vdso_enabled) \
if (vdso64_enabled) \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
(unsigned long)current->mm->context.vdso); \
(unsigned long __force)current->mm->context.vdso); \
} while (0)
/* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
#define ARCH_DLINFO_X32 \
do { \
if (vdso_enabled) \
if (vdso64_enabled) \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
(unsigned long)current->mm->context.vdso); \
(unsigned long __force)current->mm->context.vdso); \
} while (0)
#define AT_SYSINFO 32
@ -310,7 +316,7 @@ do { \
if (test_thread_flag(TIF_X32)) \
ARCH_DLINFO_X32; \
else \
ARCH_DLINFO_IA32(sysctl_vsyscall32)
ARCH_DLINFO_IA32
#define COMPAT_ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE + 0x1000000)
@ -319,18 +325,17 @@ else \
#define VDSO_CURRENT_BASE ((unsigned long)current->mm->context.vdso)
#define VDSO_ENTRY \
((unsigned long)VDSO32_SYMBOL(VDSO_CURRENT_BASE, vsyscall))
((unsigned long)current->mm->context.vdso + \
selected_vdso32->sym___kernel_vsyscall)
struct linux_binprm;
#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
extern int arch_setup_additional_pages(struct linux_binprm *bprm,
int uses_interp);
extern int x32_setup_additional_pages(struct linux_binprm *bprm,
int uses_interp);
extern int syscall32_setup_pages(struct linux_binprm *, int exstack);
#define compat_arch_setup_additional_pages syscall32_setup_pages
extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
int uses_interp);
#define compat_arch_setup_additional_pages compat_arch_setup_additional_pages
extern unsigned long arch_randomize_brk(struct mm_struct *mm);
#define arch_randomize_brk arch_randomize_brk

11
arch/x86/include/asm/fixmap.h
View File

@ -24,7 +24,7 @@
#include <linux/threads.h>
#include <asm/kmap_types.h>
#else
#include <asm/vsyscall.h>
#include <uapi/asm/vsyscall.h>
#endif
/*
@ -41,7 +41,8 @@
extern unsigned long __FIXADDR_TOP;
#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
#else
#define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE)
#define FIXADDR_TOP (round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
PAGE_SIZE)
#endif
@ -68,11 +69,7 @@ enum fixed_addresses {
#ifdef CONFIG_X86_32
FIX_HOLE,
#else
VSYSCALL_LAST_PAGE,
VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE
+ ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
VVAR_PAGE,
VSYSCALL_HPET,
VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
#ifdef CONFIG_PARAVIRT_CLOCK
PVCLOCK_FIXMAP_BEGIN,
PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1,

2
arch/x86/include/asm/mmu.h
View File

@ -18,7 +18,7 @@ typedef struct {
#endif
struct mutex lock;
void *vdso;
void __user *vdso;
} mm_context_t;
#ifdef CONFIG_SMP

2
arch/x86/include/asm/proto.h
View File

@ -12,8 +12,6 @@ void ia32_syscall(void);
void ia32_cstar_target(void);
void ia32_sysenter_target(void);
void syscall32_cpu_init(void);
void x86_configure_nx(void);
void x86_report_nx(void);

80
arch/x86/include/asm/vdso.h
View File

@ -3,63 +3,51 @@
#include <asm/page_types.h>
#include <linux/linkage.h>
#include <linux/init.h>
#ifdef __ASSEMBLER__
#ifndef __ASSEMBLER__
#define DEFINE_VDSO_IMAGE(symname, filename) \
__PAGE_ALIGNED_DATA ; \
.globl symname##_start, symname##_end ; \
.align PAGE_SIZE ; \
symname##_start: ; \
.incbin filename ; \
symname##_end: ; \
.align PAGE_SIZE /* extra data here leaks to userspace. */ ; \
\
.previous ; \
\
.globl symname##_pages ; \
.bss ; \
.align 8 ; \
.type symname##_pages, @object ; \
symname##_pages: ; \
.zero (symname##_end - symname##_start + PAGE_SIZE - 1) / PAGE_SIZE * (BITS_PER_LONG / 8) ; \
.size symname##_pages, .-symname##_pages
#include <linux/mm_types.h>
#else
struct vdso_image {
void *data;
unsigned long size; /* Always a multiple of PAGE_SIZE */
#define DECLARE_VDSO_IMAGE(symname) \
extern char symname##_start[], symname##_end[]; \
extern struct page *symname##_pages[]
/* text_mapping.pages is big enough for data/size page pointers */
struct vm_special_mapping text_mapping;
unsigned long alt, alt_len;
unsigned long sym_end_mapping; /* Total size of the mapping */
unsigned long sym_vvar_page;
unsigned long sym_hpet_page;
unsigned long sym_VDSO32_NOTE_MASK;
unsigned long sym___kernel_sigreturn;
unsigned long sym___kernel_rt_sigreturn;
unsigned long sym___kernel_vsyscall;
unsigned long sym_VDSO32_SYSENTER_RETURN;
};
#ifdef CONFIG_X86_64
extern const struct vdso_image vdso_image_64;
#endif
#ifdef CONFIG_X86_X32
extern const struct vdso_image vdso_image_x32;
#endif
#if defined CONFIG_X86_32 || defined CONFIG_COMPAT
#include <asm/vdso32.h>
DECLARE_VDSO_IMAGE(vdso32_int80);
extern const struct vdso_image vdso_image_32_int80;
#ifdef CONFIG_COMPAT
DECLARE_VDSO_IMAGE(vdso32_syscall);
extern const struct vdso_image vdso_image_32_syscall;
#endif
DECLARE_VDSO_IMAGE(vdso32_sysenter);
extern const struct vdso_image vdso_image_32_sysenter;
/*
* Given a pointer to the vDSO image, find the pointer to VDSO32_name
* as that symbol is defined in the vDSO sources or linker script.
*/
#define VDSO32_SYMBOL(base, name) \
({ \
extern const char VDSO32_##name[]; \
(void __user *)(VDSO32_##name + (unsigned long)(base)); \
})
extern const struct vdso_image *selected_vdso32;
#endif
/*
* These symbols are defined with the addresses in the vsyscall page.
* See vsyscall-sigreturn.S.
*/
extern void __user __kernel_sigreturn;
extern void __user __kernel_rt_sigreturn;
void __init patch_vdso32(void *vdso, size_t len);
extern void __init init_vdso_image(const struct vdso_image *image);
#endif /* __ASSEMBLER__ */

11
arch/x86/include/asm/vdso32.h
View File

@ -1,11 +0,0 @@
#ifndef _ASM_X86_VDSO32_H
#define _ASM_X86_VDSO32_H
#define VDSO_BASE_PAGE 0
#define VDSO_VVAR_PAGE 1
#define VDSO_HPET_PAGE 2
#define VDSO_PAGES 3
#define VDSO_PREV_PAGES 2
#define VDSO_OFFSET(x) ((x) * PAGE_SIZE)
#endif

20
arch/x86/include/asm/vvar.h
View File

@ -29,31 +29,13 @@
#else
#ifdef BUILD_VDSO32
extern char __vvar_page;
#define DECLARE_VVAR(offset, type, name) \
extern type vvar_ ## name __attribute__((visibility("hidden")));
#define VVAR(name) (vvar_ ## name)
#else
extern char __vvar_page;
/* Base address of vvars. This is not ABI. */
#ifdef CONFIG_X86_64
#define VVAR_ADDRESS (-10*1024*1024 - 4096)
#else
#define VVAR_ADDRESS (&__vvar_page)
#endif
#define DECLARE_VVAR(offset, type, name) \
static type const * const vvaraddr_ ## name = \
(void *)(VVAR_ADDRESS + (offset));
#define VVAR(name) (*vvaraddr_ ## name)
#endif
#define DEFINE_VVAR(type, name) \
type name \
__attribute__((section(".vvar_" #name), aligned(16))) __visible

7
arch/x86/include/uapi/asm/vsyscall.h
View File

@ -7,11 +7,6 @@ enum vsyscall_num {
__NR_vgetcpu,
};
#define VSYSCALL_START (-10UL << 20)
#define VSYSCALL_SIZE 1024
#define VSYSCALL_END (-2UL << 20)
#define VSYSCALL_MAPPED_PAGES 1
#define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr))
#define VSYSCALL_ADDR (-10UL << 20)
#endif /* _UAPI_ASM_X86_VSYSCALL_H */

33
arch/x86/kernel/cpu/common.c
View File

@ -20,6 +20,7 @@
#include <asm/processor.h>
#include <asm/debugreg.h>
#include <asm/sections.h>
#include <asm/vsyscall.h>
#include <linux/topology.h>
#include <linux/cpumask.h>
#include <asm/pgtable.h>
@ -953,6 +954,38 @@ static void vgetcpu_set_mode(void)
else
vgetcpu_mode = VGETCPU_LSL;
}
/* May not be __init: called during resume */
static void syscall32_cpu_init(void)
{
/* Load these always in case some future AMD CPU supports
SYSENTER from compat mode too. */
wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
wrmsrl(MSR_CSTAR, ia32_cstar_target);
}
#endif
#ifdef CONFIG_X86_32
void enable_sep_cpu(void)
{
int cpu = get_cpu();
struct tss_struct *tss = &per_cpu(init_tss, cpu);
if (!boot_cpu_has(X86_FEATURE_SEP)) {
put_cpu();
return;
}
tss->x86_tss.ss1 = __KERNEL_CS;
tss->x86_tss.sp1 = sizeof(struct tss_struct) + (unsigned long) tss;
wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
wrmsr(MSR_IA32_SYSENTER_ESP, tss->x86_tss.sp1, 0);
wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) ia32_sysenter_target, 0);
put_cpu();
}
#endif
void __init identify_boot_cpu(void)

3
arch/x86/kernel/hpet.c
View File

@ -74,9 +74,6 @@ static inline void hpet_writel(unsigned int d, unsigned int a)
static inline void hpet_set_mapping(void)
{
hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
#ifdef CONFIG_X86_64
__set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VVAR_NOCACHE);
#endif
}
static inline void hpet_clear_mapping(void)

6
arch/x86/kernel/signal.c
View File

@ -298,7 +298,8 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
}
if (current->mm->context.vdso)
restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
restorer = current->mm->context.vdso +
selected_vdso32->sym___kernel_sigreturn;
else
restorer = &frame->retcode;
if (ksig->ka.sa.sa_flags & SA_RESTORER)
@ -361,7 +362,8 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
save_altstack_ex(&frame->uc.uc_stack, regs->sp);
/* Set up to return from userspace. */
restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
restorer = current->mm->context.vdso +
selected_vdso32->sym___kernel_sigreturn;
if (ksig->ka.sa.sa_flags & SA_RESTORER)
restorer = ksig->ka.sa.sa_restorer;
put_user_ex(restorer, &frame->pretcode);

15
arch/x86/kernel/vsyscall_64.c
View File

@ -91,7 +91,7 @@ static int addr_to_vsyscall_nr(unsigned long addr)
{
int nr;
if ((addr & ~0xC00UL) != VSYSCALL_START)
if ((addr & ~0xC00UL) != VSYSCALL_ADDR)
return -EINVAL;
nr = (addr & 0xC00UL) >> 10;
@ -330,24 +330,17 @@ void __init map_vsyscall(void)
{
extern char __vsyscall_page;
unsigned long physaddr_vsyscall = __pa_symbol(&__vsyscall_page);
unsigned long physaddr_vvar_page = __pa_symbol(&__vvar_page);
__set_fixmap(VSYSCALL_FIRST_PAGE, physaddr_vsyscall,
__set_fixmap(VSYSCALL_PAGE, physaddr_vsyscall,
vsyscall_mode == NATIVE
? PAGE_KERNEL_VSYSCALL
: PAGE_KERNEL_VVAR);
BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_FIRST_PAGE) !=
(unsigned long)VSYSCALL_START);
__set_fixmap(VVAR_PAGE, physaddr_vvar_page, PAGE_KERNEL_VVAR);
BUILD_BUG_ON((unsigned long)__fix_to_virt(VVAR_PAGE) !=
(unsigned long)VVAR_ADDRESS);
BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_PAGE) !=
(unsigned long)VSYSCALL_ADDR);
}
static int __init vsyscall_init(void)
{
BUG_ON(VSYSCALL_ADDR(0) != __fix_to_virt(VSYSCALL_FIRST_PAGE));
cpu_notifier_register_begin();
on_each_cpu(cpu_vsyscall_init, NULL, 1);

5
arch/x86/mm/fault.c
View File

@ -18,7 +18,8 @@
#include <asm/traps.h> /* dotraplinkage, ... */
#include <asm/pgalloc.h> /* pgd_*(), ... */
#include <asm/kmemcheck.h> /* kmemcheck_*(), ... */
#include <asm/fixmap.h> /* VSYSCALL_START */
#include <asm/fixmap.h> /* VSYSCALL_ADDR */
#include <asm/vsyscall.h> /* emulate_vsyscall */
#define CREATE_TRACE_POINTS
#include <asm/trace/exceptions.h>
@ -771,7 +772,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
* emulation.
*/
if (unlikely((error_code & PF_INSTR) &&
((address & ~0xfff) == VSYSCALL_START))) {
((address & ~0xfff) == VSYSCALL_ADDR))) {
if (emulate_vsyscall(regs, address))
return;
}

29
arch/x86/mm/init_64.c
View File

@ -1055,8 +1055,8 @@ void __init mem_init(void)
after_bootmem = 1;
/* Register memory areas for /proc/kcore */
kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR,
PAGE_SIZE, KCORE_OTHER);
mem_init_print_info(NULL);
}
@ -1185,11 +1185,19 @@ int kern_addr_valid(unsigned long addr)
* covers the 64bit vsyscall page now. 32bit has a real VMA now and does
* not need special handling anymore:
*/
static const char *gate_vma_name(struct vm_area_struct *vma)
{
return "[vsyscall]";
}
static struct vm_operations_struct gate_vma_ops = {
.name = gate_vma_name,
};
static struct vm_area_struct gate_vma = {
.vm_start = VSYSCALL_START,
.vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
.vm_start = VSYSCALL_ADDR,
.vm_end = VSYSCALL_ADDR + PAGE_SIZE,
.vm_page_prot = PAGE_READONLY_EXEC,
.vm_flags = VM_READ | VM_EXEC
.vm_flags = VM_READ | VM_EXEC,
.vm_ops = &gate_vma_ops,
};
struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
@ -1218,16 +1226,7 @@ int in_gate_area(struct mm_struct *mm, unsigned long addr)
*/
int in_gate_area_no_mm(unsigned long addr)
{
return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
}
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]";
if (vma == &gate_vma)
return "[vsyscall]";
return NULL;
return (addr & PAGE_MASK) == VSYSCALL_ADDR;
}
static unsigned long probe_memory_block_size(void)

6
arch/x86/mm/ioremap.c
View File

@ -367,6 +367,12 @@ void __init early_ioremap_init(void)
{
pmd_t *pmd;
#ifdef CONFIG_X86_64
BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
#else
WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
#endif
early_ioremap_setup();
pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));

6
arch/x86/mm/pgtable.c
View File

@ -456,9 +456,9 @@ void __init reserve_top_address(unsigned long reserve)
{
#ifdef CONFIG_X86_32
BUG_ON(fixmaps_set > 0);
printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
(int)-reserve);
__FIXADDR_TOP = -reserve - PAGE_SIZE;
__FIXADDR_TOP = round_down(-reserve, 1 << PMD_SHIFT) - PAGE_SIZE;
printk(KERN_INFO "Reserving virtual address space above 0x%08lx (rounded to 0x%08lx)\n",
-reserve, __FIXADDR_TOP + PAGE_SIZE);
#endif
}

2
arch/x86/um/vdso/vma.c
View File

@ -12,7 +12,7 @@
#include <asm/page.h>
#include <linux/init.h>
unsigned int __read_mostly vdso_enabled = 1;
static unsigned int __read_mostly vdso_enabled = 1;
unsigned long um_vdso_addr;
extern unsigned long task_size;

5
arch/x86/vdso/.gitignore vendored
View File

@ -1,8 +1,7 @@
vdso.lds
vdso-syms.lds
vdsox32.lds
vdsox32-syms.lds
vdso32-syms.lds
vdso32-syscall-syms.lds
vdso32-sysenter-syms.lds
vdso32-int80-syms.lds
vdso-image-*.c
vdso2c

90
arch/x86/vdso/Makefile
View File

@ -24,15 +24,30 @@ vobj64s := $(filter-out $(vobjx32s-compat),$(vobjs-y))
# files to link into kernel
obj-y += vma.o
obj-$(VDSO64-y) += vdso.o
obj-$(VDSOX32-y) += vdsox32.o
obj-$(VDSO32-y) += vdso32.o vdso32-setup.o
# vDSO images to build
vdso_img-$(VDSO64-y) += 64
vdso_img-$(VDSOX32-y) += x32
vdso_img-$(VDSO32-y) += 32-int80
vdso_img-$(CONFIG_COMPAT) += 32-syscall
vdso_img-$(VDSO32-y) += 32-sysenter
obj-$(VDSO32-y) += vdso32-setup.o
vobjs := $(foreach F,$(vobj64s),$(obj)/$F)
$(obj)/vdso.o: $(obj)/vdso.so
targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
targets += vdso.lds $(vobjs-y)
# Build the vDSO image C files and link them in.
vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
obj-y += $(vdso_img_objs)
targets += $(vdso_img_cfiles)
targets += $(vdso_img_sodbg)
.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c)
export CPPFLAGS_vdso.lds += -P -C
@ -41,14 +56,18 @@ VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
-Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
$(DISABLE_LTO)
$(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
$(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
$(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
$(call if_changed,vdso)
$(obj)/%.so: OBJCOPYFLAGS := -S
$(obj)/%.so: $(obj)/%.so.dbg FORCE
$(call if_changed,objcopy)
hostprogs-y += vdso2c
quiet_cmd_vdso2c = VDSO2C $@
define cmd_vdso2c
$(obj)/vdso2c $< $@
endef
$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso2c FORCE
$(call if_changed,vdso2c)
#
# Don't omit frame pointers for ease of userspace debugging, but do
@ -68,22 +87,6 @@ CFLAGS_REMOVE_vclock_gettime.o = -pg
CFLAGS_REMOVE_vgetcpu.o = -pg
CFLAGS_REMOVE_vvar.o = -pg
targets += vdso-syms.lds
obj-$(VDSO64-y) += vdso-syms.lds
#
# Match symbols in the DSO that look like VDSO*; produce a file of constants.
#
sed-vdsosym := -e 's/^00*/0/' \
-e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
quiet_cmd_vdsosym = VDSOSYM $@
define cmd_vdsosym
$(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
endef
$(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
$(call if_changed,vdsosym)
#
# X32 processes use x32 vDSO to access 64bit kernel data.
#
@ -94,9 +97,6 @@ $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
# so that it can reach 64bit address space with 64bit pointers.
#
targets += vdsox32-syms.lds
obj-$(VDSOX32-y) += vdsox32-syms.lds
CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
-Wl,-soname=linux-vdso.so.1 \
@ -113,9 +113,7 @@ quiet_cmd_x32 = X32 $@
$(obj)/%-x32.o: $(obj)/%.o FORCE
$(call if_changed,x32)
targets += vdsox32.so vdsox32.so.dbg vdsox32.lds $(vobjx32s-y)
$(obj)/vdsox32.o: $(src)/vdsox32.S $(obj)/vdsox32.so
targets += vdsox32.lds $(vobjx32s-y)
$(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
$(call if_changed,vdso)
@ -123,7 +121,6 @@ $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
#
# Build multiple 32-bit vDSO images to choose from at boot time.
#
obj-$(VDSO32-y) += vdso32-syms.lds
vdso32.so-$(VDSO32-y) += int80
vdso32.so-$(CONFIG_COMPAT) += syscall
vdso32.so-$(VDSO32-y) += sysenter
@ -138,10 +135,8 @@ VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
targets += vdso32/vdso32.lds
targets += $(vdso32-images) $(vdso32-images:=.dbg)
targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
extra-y += $(vdso32-images)
targets += vdso32/vclock_gettime.o
$(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
@ -166,27 +161,6 @@ $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
$(obj)/vdso32/%.o
$(call if_changed,vdso)
# Make vdso32-*-syms.lds from each image, and then make sure they match.
# The only difference should be that some do not define VDSO32_SYSENTER_RETURN.
targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
quiet_cmd_vdso32sym = VDSOSYM $@
define cmd_vdso32sym
if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \
$(foreach H,$(filter-out FORCE,$^),\
if grep -q VDSO32_SYSENTER_RETURN $H; \
then diff -u $(@D)/.tmp_$(@F) $H; \
else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \
diff -u - $H; fi &&) : ;\
then mv -f $(@D)/.tmp_$(@F) $@; \
else rm -f $(@D)/.tmp_$(@F); exit 1; \
fi
endef
$(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
$(call if_changed,vdso32sym)
#
# The DSO images are built using a special linker script.
#
@ -197,7 +171,7 @@ quiet_cmd_vdso = VDSO $@
sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
$(LTO_CFLAGS)
-Wl,-Bsymbolic $(LTO_CFLAGS)
GCOV_PROFILE := n
#

26
arch/x86/vdso/vclock_gettime.c
View File

@ -30,9 +30,12 @@ extern int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz);
extern time_t __vdso_time(time_t *t);
#ifdef CONFIG_HPET_TIMER
static inline u32 read_hpet_counter(const volatile void *addr)
extern u8 hpet_page
__attribute__((visibility("hidden")));
static notrace cycle_t vread_hpet(void)
{
return *(const volatile u32 *) (addr + HPET_COUNTER);
return *(const volatile u32 *)(&hpet_page + HPET_COUNTER);
}
#endif
@ -43,11 +46,6 @@ static inline u32 read_hpet_counter(const volatile void *addr)
#include <asm/fixmap.h>
#include <asm/pvclock.h>
static notrace cycle_t vread_hpet(void)
{
return read_hpet_counter((const void *)fix_to_virt(VSYSCALL_HPET));
}
notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
{
long ret;
@ -137,16 +135,6 @@ static notrace cycle_t vread_pvclock(int *mode)
#else
extern u8 hpet_page
__attribute__((visibility("hidden")));
#ifdef CONFIG_HPET_TIMER
static notrace cycle_t vread_hpet(void)
{
return read_hpet_counter((const void *)(&hpet_page));
}
#endif
notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
{
long ret;
@ -154,7 +142,7 @@ notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
asm(
"mov %%ebx, %%edx \n"
"mov %2, %%ebx \n"
"call VDSO32_vsyscall \n"
"call __kernel_vsyscall \n"
"mov %%edx, %%ebx \n"
: "=a" (ret)
: "0" (__NR_clock_gettime), "g" (clock), "c" (ts)
@ -169,7 +157,7 @@ notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
asm(
"mov %%ebx, %%edx \n"
"mov %2, %%ebx \n"
"call VDSO32_vsyscall \n"
"call __kernel_vsyscall \n"
"mov %%edx, %%ebx \n"
: "=a" (ret)
: "0" (__NR_gettimeofday), "g" (tv), "c" (tz)

40
arch/x86/vdso/vdso-layout.lds.S
View File

@ -1,3 +1,5 @@
#include <asm/vdso.h>
/*
* Linker script for vDSO. This is an ELF shared object prelinked to
* its virtual address, and with only one read-only segment.
@ -6,20 +8,6 @@
SECTIONS
{
#ifdef BUILD_VDSO32
#include <asm/vdso32.h>
hpet_page = . - VDSO_OFFSET(VDSO_HPET_PAGE);
vvar = . - VDSO_OFFSET(VDSO_VVAR_PAGE);
/* Place all vvars at the offsets in asm/vvar.h. */
#define EMIT_VVAR(name, offset) vvar_ ## name = vvar + offset;
#define __VVAR_KERNEL_LDS
#include <asm/vvar.h>
#undef __VVAR_KERNEL_LDS
#undef EMIT_VVAR
#endif
. = SIZEOF_HEADERS;
.hash : { *(.hash) } :text
@ -60,10 +48,30 @@ SECTIONS
.text : { *(.text*) } :text =0x90909090,
/*
* The comma above works around a bug in gold:
* https://sourceware.org/bugzilla/show_bug.cgi?id=16804
* The remainder of the vDSO consists of special pages that are
* shared between the kernel and userspace. It needs to be at the
* end so that it doesn't overlap the mapping of the actual
* vDSO image.
*/
. = ALIGN(PAGE_SIZE);
vvar_page = .;
/* Place all vvars at the offsets in asm/vvar.h. */
#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
#define __VVAR_KERNEL_LDS
#include <asm/vvar.h>
#undef __VVAR_KERNEL_LDS
#undef EMIT_VVAR
. = vvar_page + PAGE_SIZE;
hpet_page = .;
. = . + PAGE_SIZE;
. = ALIGN(PAGE_SIZE);
end_mapping = .;
/DISCARD/ : {
*(.discard)
*(.discard.*)

3
arch/x86/vdso/vdso.S
View File

@ -1,3 +0,0 @@
#include <asm/vdso.h>
DEFINE_VDSO_IMAGE(vdso, "arch/x86/vdso/vdso.so")

7
arch/x86/vdso/vdso.lds.S
View File

@ -1,14 +1,11 @@
/*
* Linker script for 64-bit vDSO.
* We #include the file to define the layout details.
* Here we only choose the prelinked virtual address.
*
* This file defines the version script giving the user-exported symbols in
* the DSO. We can define local symbols here called VDSO* to make their
* values visible using the asm-x86/vdso.h macros from the kernel proper.
* the DSO.
*/
#define VDSO_PRELINK 0xffffffffff700000
#include "vdso-layout.lds.S"
/*
@ -28,5 +25,3 @@ VERSION {
local: *;
};
}
VDSO64_PRELINK = VDSO_PRELINK;

173
arch/x86/vdso/vdso2c.c Normal file
View File

@ -0,0 +1,173 @@
#include <inttypes.h>
#include <stdint.h>
#include <unistd.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <err.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <linux/elf.h>
#include <linux/types.h>
const char *outfilename;
/* Symbols that we need in vdso2c. */
enum {
sym_vvar_page,
sym_hpet_page,
sym_end_mapping,
};
const int special_pages[] = {
sym_vvar_page,
sym_hpet_page,
};
char const * const required_syms[] = {
[sym_vvar_page] = "vvar_page",
[sym_hpet_page] = "hpet_page",
[sym_end_mapping] = "end_mapping",
"VDSO32_NOTE_MASK",
"VDSO32_SYSENTER_RETURN",
"__kernel_vsyscall",
"__kernel_sigreturn",
"__kernel_rt_sigreturn",
};
__attribute__((format(printf, 1, 2))) __attribute__((noreturn))
static void fail(const char *format, ...)
{
va_list ap;
va_start(ap, format);
fprintf(stderr, "Error: ");
vfprintf(stderr, format, ap);
unlink(outfilename);
exit(1);
va_end(ap);
}
/*
* Evil macros to do a little-endian read.
*/
#define GLE(x, bits, ifnot) \
__builtin_choose_expr( \
(sizeof(x) == bits/8), \
(__typeof__(x))le##bits##toh(x), ifnot)
extern void bad_get_le(uint64_t);
#define LAST_LE(x) \
__builtin_choose_expr(sizeof(x) == 1, (x), bad_get_le(x))
#define GET_LE(x) \
GLE(x, 64, GLE(x, 32, GLE(x, 16, LAST_LE(x))))
#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
#define BITS 64
#define GOFUNC go64
#define Elf_Ehdr Elf64_Ehdr
#define Elf_Shdr Elf64_Shdr
#define Elf_Phdr Elf64_Phdr
#define Elf_Sym Elf64_Sym
#define Elf_Dyn Elf64_Dyn
#include "vdso2c.h"
#undef BITS
#undef GOFUNC
#undef Elf_Ehdr
#undef Elf_Shdr
#undef Elf_Phdr
#undef Elf_Sym
#undef Elf_Dyn
#define BITS 32
#define GOFUNC go32
#define Elf_Ehdr Elf32_Ehdr
#define Elf_Shdr Elf32_Shdr
#define Elf_Phdr Elf32_Phdr
#define Elf_Sym Elf32_Sym
#define Elf_Dyn Elf32_Dyn
#include "vdso2c.h"
#undef BITS
#undef GOFUNC
#undef Elf_Ehdr
#undef Elf_Shdr
#undef Elf_Phdr
#undef Elf_Sym
#undef Elf_Dyn
static void go(void *addr, size_t len, FILE *outfile, const char *name)
{
Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr;
if (hdr->e_ident[EI_CLASS] == ELFCLASS64) {
go64(addr, len, outfile, name);
} else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) {
go32(addr, len, outfile, name);
} else {
fail("unknown ELF class\n");
}
}
int main(int argc, char **argv)
{
int fd;
off_t len;
void *addr;
FILE *outfile;
char *name, *tmp;
int namelen;
if (argc != 3) {
printf("Usage: vdso2c INPUT OUTPUT\n");
return 1;
}
/*
* Figure out the struct name. If we're writing to a .so file,
* generate raw output insted.
*/
name = strdup(argv[2]);
namelen = strlen(name);
if (namelen >= 3 && !strcmp(name + namelen - 3, ".so")) {
name = NULL;
} else {
tmp = strrchr(name, '/');
if (tmp)
name = tmp + 1;
tmp = strchr(name, '.');
if (tmp)
*tmp = '\0';
for (tmp = name; *tmp; tmp++)
if (*tmp == '-')
*tmp = '_';
}
fd = open(argv[1], O_RDONLY);
if (fd == -1)
err(1, "%s", argv[1]);
len = lseek(fd, 0, SEEK_END);
if (len == (off_t)-1)
err(1, "lseek");
addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
if (addr == MAP_FAILED)
err(1, "mmap");
outfilename = argv[2];
outfile = fopen(outfilename, "w");
if (!outfile)
err(1, "%s", argv[2]);
go(addr, (size_t)len, outfile, name);
munmap(addr, len);
fclose(outfile);
return 0;
}

163
arch/x86/vdso/vdso2c.h Normal file
View File

@ -0,0 +1,163 @@
/*
* This file is included twice from vdso2c.c. It generates code for 32-bit
* and 64-bit vDSOs. We need both for 64-bit builds, since 32-bit vDSOs
* are built for 32-bit userspace.
*/
static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
{
int found_load = 0;
unsigned long load_size = -1; /* Work around bogus warning */
unsigned long data_size;
Elf_Ehdr *hdr = (Elf_Ehdr *)addr;
int i;
unsigned long j;
Elf_Shdr *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
*alt_sec = NULL;
Elf_Dyn *dyn = 0, *dyn_end = 0;
const char *secstrings;
uint64_t syms[NSYMS] = {};
Elf_Phdr *pt = (Elf_Phdr *)(addr + GET_LE(hdr->e_phoff));
/* Walk the segment table. */
for (i = 0; i < GET_LE(hdr->e_phnum); i++) {
if (GET_LE(pt[i].p_type) == PT_LOAD) {
if (found_load)
fail("multiple PT_LOAD segs\n");
if (GET_LE(pt[i].p_offset) != 0 ||
GET_LE(pt[i].p_vaddr) != 0)
fail("PT_LOAD in wrong place\n");
if (GET_LE(pt[i].p_memsz) != GET_LE(pt[i].p_filesz))
fail("cannot handle memsz != filesz\n");
load_size = GET_LE(pt[i].p_memsz);
found_load = 1;
} else if (GET_LE(pt[i].p_type) == PT_DYNAMIC) {
dyn = addr + GET_LE(pt[i].p_offset);
dyn_end = addr + GET_LE(pt[i].p_offset) +
GET_LE(pt[i].p_memsz);
}
}
if (!found_load)
fail("no PT_LOAD seg\n");
data_size = (load_size + 4095) / 4096 * 4096;
/* Walk the dynamic table */
for (i = 0; dyn + i < dyn_end &&
GET_LE(dyn[i].d_tag) != DT_NULL; i++) {
typeof(dyn[i].d_tag) tag = GET_LE(dyn[i].d_tag);
if (tag == DT_REL || tag == DT_RELSZ ||
tag == DT_RELENT || tag == DT_TEXTREL)
fail("vdso image contains dynamic relocations\n");
}
/* Walk the section table */
secstrings_hdr = addr + GET_LE(hdr->e_shoff) +
GET_LE(hdr->e_shentsize)*GET_LE(hdr->e_shstrndx);
secstrings = addr + GET_LE(secstrings_hdr->sh_offset);
for (i = 0; i < GET_LE(hdr->e_shnum); i++) {
Elf_Shdr *sh = addr + GET_LE(hdr->e_shoff) +
GET_LE(hdr->e_shentsize) * i;
if (GET_LE(sh->sh_type) == SHT_SYMTAB)
symtab_hdr = sh;
if (!strcmp(secstrings + GET_LE(sh->sh_name),
".altinstructions"))
alt_sec = sh;
}
if (!symtab_hdr)
fail("no symbol table\n");
strtab_hdr = addr + GET_LE(hdr->e_shoff) +
GET_LE(hdr->e_shentsize) * GET_LE(symtab_hdr->sh_link);
/* Walk the symbol table */
for (i = 0;
i < GET_LE(symtab_hdr->sh_size) / GET_LE(symtab_hdr->sh_entsize);
i++) {
int k;
Elf_Sym *sym = addr + GET_LE(symtab_hdr->sh_offset) +
GET_LE(symtab_hdr->sh_entsize) * i;
const char *name = addr + GET_LE(strtab_hdr->sh_offset) +
GET_LE(sym->st_name);
for (k = 0; k < NSYMS; k++) {
if (!strcmp(name, required_syms[k])) {
if (syms[k]) {
fail("duplicate symbol %s\n",
required_syms[k]);
}
syms[k] = GET_LE(sym->st_value);
}
}
}
/* Validate mapping addresses. */
for (i = 0; i < sizeof(special_pages) / sizeof(special_pages[0]); i++) {
if (!syms[i])
continue; /* The mapping isn't used; ignore it. */
if (syms[i] % 4096)
fail("%s must be a multiple of 4096\n",
required_syms[i]);
if (syms[i] < data_size)
fail("%s must be after the text mapping\n",
required_syms[i]);
if (syms[sym_end_mapping] < syms[i] + 4096)
fail("%s overruns end_mapping\n", required_syms[i]);
}
if (syms[sym_end_mapping] % 4096)
fail("end_mapping must be a multiple of 4096\n");
/* Remove sections. */
hdr->e_shoff = 0;
hdr->e_shentsize = 0;
hdr->e_shnum = 0;
hdr->e_shstrndx = htole16(SHN_UNDEF);
if (!name) {
fwrite(addr, load_size, 1, outfile);
return;
}
fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
fprintf(outfile, "#include <linux/linkage.h>\n");
fprintf(outfile, "#include <asm/page_types.h>\n");
fprintf(outfile, "#include <asm/vdso.h>\n");
fprintf(outfile, "\n");
fprintf(outfile,
"static unsigned char raw_data[%lu] __page_aligned_data = {",
data_size);
for (j = 0; j < load_size; j++) {
if (j % 10 == 0)
fprintf(outfile, "\n\t");
fprintf(outfile, "0x%02X, ", (int)((unsigned char *)addr)[j]);
}
fprintf(outfile, "\n};\n\n");
fprintf(outfile, "static struct page *pages[%lu];\n\n",
data_size / 4096);
fprintf(outfile, "const struct vdso_image %s = {\n", name);
fprintf(outfile, "\t.data = raw_data,\n");
fprintf(outfile, "\t.size = %lu,\n", data_size);
fprintf(outfile, "\t.text_mapping = {\n");
fprintf(outfile, "\t\t.name = \"[vdso]\",\n");
fprintf(outfile, "\t\t.pages = pages,\n");
fprintf(outfile, "\t},\n");
if (alt_sec) {
fprintf(outfile, "\t.alt = %lu,\n",
(unsigned long)GET_LE(alt_sec->sh_offset));
fprintf(outfile, "\t.alt_len = %lu,\n",
(unsigned long)GET_LE(alt_sec->sh_size));
}
for (i = 0; i < NSYMS; i++) {
if (syms[i])
fprintf(outfile, "\t.sym_%s = 0x%" PRIx64 ",\n",
required_syms[i], syms[i]);
}
fprintf(outfile, "};\n");
}

203
arch/x86/vdso/vdso32-setup.c
View File

@ -8,27 +8,12 @@
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/thread_info.h>
#include <linux/sched.h>
#include <linux/gfp.h>
#include <linux/string.h>
#include <linux/elf.h>
#include <linux/mm.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/mm_types.h>
#include <asm/cpufeature.h>
#include <asm/msr.h>
#include <asm/pgtable.h>
#include <asm/unistd.h>
#include <asm/elf.h>
#include <asm/tlbflush.h>
#include <asm/processor.h>
#include <asm/vdso.h>
#include <asm/proto.h>
#include <asm/fixmap.h>
#include <asm/hpet.h>
#include <asm/vvar.h>
#ifdef CONFIG_COMPAT_VDSO
#define VDSO_DEFAULT 0
@ -36,22 +21,17 @@
#define VDSO_DEFAULT 1
#endif
#ifdef CONFIG_X86_64
#define vdso_enabled sysctl_vsyscall32
#define arch_setup_additional_pages syscall32_setup_pages
#endif
/*
* Should the kernel map a VDSO page into processes and pass its
* address down to glibc upon exec()?
*/
unsigned int __read_mostly vdso_enabled = VDSO_DEFAULT;
unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;
static int __init vdso_setup(char *s)
static int __init vdso32_setup(char *s)
{
vdso_enabled = simple_strtoul(s, NULL, 0);
vdso32_enabled = simple_strtoul(s, NULL, 0);
if (vdso_enabled > 1)
if (vdso32_enabled > 1)
pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
return 1;
@ -62,177 +42,45 @@ static int __init vdso_setup(char *s)
* behavior on both 64-bit and 32-bit kernels.
* On 32-bit kernels, vdso=[012] means the same thing.
*/
__setup("vdso32=", vdso_setup);
__setup("vdso32=", vdso32_setup);
#ifdef CONFIG_X86_32
__setup_param("vdso=", vdso32_setup, vdso_setup, 0);
EXPORT_SYMBOL_GPL(vdso_enabled);
__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
#endif
static struct page **vdso32_pages;
static unsigned vdso32_size;
#ifdef CONFIG_X86_64
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SYSENTER32))
#define vdso32_syscall() (boot_cpu_has(X86_FEATURE_SYSCALL32))
/* May not be __init: called during resume */
void syscall32_cpu_init(void)
{
/* Load these always in case some future AMD CPU supports
SYSENTER from compat mode too. */
wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
wrmsrl(MSR_CSTAR, ia32_cstar_target);
}
#else /* CONFIG_X86_32 */
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SEP))
#define vdso32_syscall() (0)
void enable_sep_cpu(void)
{
int cpu = get_cpu();
struct tss_struct *tss = &per_cpu(init_tss, cpu);
if (!boot_cpu_has(X86_FEATURE_SEP)) {
put_cpu();
return;
}
tss->x86_tss.ss1 = __KERNEL_CS;
tss->x86_tss.sp1 = sizeof(struct tss_struct) + (unsigned long) tss;
wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
wrmsr(MSR_IA32_SYSENTER_ESP, tss->x86_tss.sp1, 0);
wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) ia32_sysenter_target, 0);
put_cpu();
}
#endif /* CONFIG_X86_64 */
#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
const struct vdso_image *selected_vdso32;
#endif
int __init sysenter_setup(void)
{
char *vdso32_start, *vdso32_end;
int npages, i;
#ifdef CONFIG_COMPAT
if (vdso32_syscall()) {
vdso32_start = vdso32_syscall_start;
vdso32_end = vdso32_syscall_end;
vdso32_pages = vdso32_syscall_pages;
} else
if (vdso32_syscall())
selected_vdso32 = &vdso_image_32_syscall;
else
#endif
if (vdso32_sysenter()) {
vdso32_start = vdso32_sysenter_start;
vdso32_end = vdso32_sysenter_end;
vdso32_pages = vdso32_sysenter_pages;
} else {
vdso32_start = vdso32_int80_start;
vdso32_end = vdso32_int80_end;
vdso32_pages = vdso32_int80_pages;
}
if (vdso32_sysenter())
selected_vdso32 = &vdso_image_32_sysenter;
else
selected_vdso32 = &vdso_image_32_int80;
npages = ((vdso32_end - vdso32_start) + PAGE_SIZE - 1) / PAGE_SIZE;
vdso32_size = npages << PAGE_SHIFT;
for (i = 0; i < npages; i++)
vdso32_pages[i] = virt_to_page(vdso32_start + i*PAGE_SIZE);
patch_vdso32(vdso32_start, vdso32_size);
init_vdso_image(selected_vdso32);
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 = 0;
struct vm_area_struct *vma;
#ifdef CONFIG_X86_X32_ABI
if (test_thread_flag(TIF_X32))
return x32_setup_additional_pages(bprm, uses_interp);
#endif
if (vdso_enabled != 1) /* Other values all mean "disabled" */
return 0;
down_write(&mm->mmap_sem);
addr = get_unmapped_area(NULL, 0, vdso32_size + VDSO_OFFSET(VDSO_PREV_PAGES), 0, 0);
if (IS_ERR_VALUE(addr)) {
ret = addr;
goto up_fail;
}
addr += VDSO_OFFSET(VDSO_PREV_PAGES);
current->mm->context.vdso = (void *)addr;
/*
* MAYWRITE to allow gdb to COW and set breakpoints
*/
ret = install_special_mapping(mm,
addr,
vdso32_size,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
vdso32_pages);
if (ret)
goto up_fail;
vma = _install_special_mapping(mm,
addr - VDSO_OFFSET(VDSO_PREV_PAGES),
VDSO_OFFSET(VDSO_PREV_PAGES),
VM_READ,
NULL);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto up_fail;
}
ret = remap_pfn_range(vma,
addr - VDSO_OFFSET(VDSO_VVAR_PAGE),
__pa_symbol(&__vvar_page) >> PAGE_SHIFT,
PAGE_SIZE,
PAGE_READONLY);
if (ret)
goto up_fail;
#ifdef CONFIG_HPET_TIMER
if (hpet_address) {
ret = io_remap_pfn_range(vma,
addr - VDSO_OFFSET(VDSO_HPET_PAGE),
hpet_address >> PAGE_SHIFT,
PAGE_SIZE,
pgprot_noncached(PAGE_READONLY));
if (ret)
goto up_fail;
}
#endif
current_thread_info()->sysenter_return =
VDSO32_SYMBOL(addr, SYSENTER_RETURN);
up_fail:
if (ret)
current->mm->context.vdso = NULL;
up_write(&mm->mmap_sem);
return ret;
}
#ifdef CONFIG_X86_64
subsys_initcall(sysenter_setup);
@ -244,7 +92,7 @@ subsys_initcall(sysenter_setup);
static struct ctl_table abi_table2[] = {
{
.procname = "vsyscall32",
.data = &sysctl_vsyscall32,
.data = &vdso32_enabled,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
@ -271,13 +119,6 @@ __initcall(ia32_binfmt_init);
#else /* CONFIG_X86_32 */
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;
}
struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
return NULL;

9
arch/x86/vdso/vdso32.S
View File

@ -1,9 +0,0 @@
#include <asm/vdso.h>
DEFINE_VDSO_IMAGE(vdso32_int80, "arch/x86/vdso/vdso32-int80.so")
#ifdef CONFIG_COMPAT
DEFINE_VDSO_IMAGE(vdso32_syscall, "arch/x86/vdso/vdso32-syscall.so")
#endif
DEFINE_VDSO_IMAGE(vdso32_sysenter, "arch/x86/vdso/vdso32-sysenter.so")

15
arch/x86/vdso/vdso32/vdso32.lds.S
View File

@ -1,17 +1,14 @@
/*
* Linker script for 32-bit vDSO.
* We #include the file to define the layout details.
* Here we only choose the prelinked virtual address.
*
* This file defines the version script giving the user-exported symbols in
* the DSO. We can define local symbols here called VDSO* to make their
* values visible using the asm-x86/vdso.h macros from the kernel proper.
* the DSO.
*/
#include <asm/page.h>
#define BUILD_VDSO32
#define VDSO_PRELINK 0
#include "../vdso-layout.lds.S"
@ -38,13 +35,3 @@ VERSION
local: *;
};
}
/*
* Symbols we define here called VDSO* get their values into vdso32-syms.h.
*/
VDSO32_vsyscall = __kernel_vsyscall;
VDSO32_sigreturn = __kernel_sigreturn;
VDSO32_rt_sigreturn = __kernel_rt_sigreturn;
VDSO32_clock_gettime = clock_gettime;
VDSO32_gettimeofday = gettimeofday;
VDSO32_time = time;

3
arch/x86/vdso/vdsox32.S
View File

@ -1,3 +0,0 @@
#include <asm/vdso.h>
DEFINE_VDSO_IMAGE(vdsox32, "arch/x86/vdso/vdsox32.so")

7
arch/x86/vdso/vdsox32.lds.S
View File

@ -1,14 +1,11 @@
/*
* Linker script for x32 vDSO.
* We #include the file to define the layout details.
* Here we only choose the prelinked virtual address.
*
* This file defines the version script giving the user-exported symbols in
* the DSO. We can define local symbols here called VDSO* to make their
* values visible using the asm-x86/vdso.h macros from the kernel proper.
* the DSO.
*/
#define VDSO_PRELINK 0
#include "vdso-layout.lds.S"
/*
@ -24,5 +21,3 @@ VERSION {
local: *;
};
}
VDSOX32_PRELINK = VDSO_PRELINK;

242
arch/x86/vdso/vma.c
View File

@ -15,115 +15,51 @@
#include <asm/proto.h>
#include <asm/vdso.h>
#include <asm/page.h>
#include <asm/hpet.h>
#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso_enabled = 1;
unsigned int __read_mostly vdso64_enabled = 1;
DECLARE_VDSO_IMAGE(vdso);
extern unsigned short vdso_sync_cpuid;
static unsigned vdso_size;
#ifdef CONFIG_X86_X32_ABI
DECLARE_VDSO_IMAGE(vdsox32);
static unsigned vdsox32_size;
#endif
#endif
#if defined(CONFIG_X86_32) || defined(CONFIG_X86_X32_ABI) || \
defined(CONFIG_COMPAT)
void __init patch_vdso32(void *vdso, size_t len)
void __init init_vdso_image(const struct vdso_image *image)
{
Elf32_Ehdr *hdr = vdso;
Elf32_Shdr *sechdrs, *alt_sec = 0;
char *secstrings;
void *alt_data;
int i;
int npages = (image->size) / PAGE_SIZE;
BUG_ON(len < sizeof(Elf32_Ehdr));
BUG_ON(memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0);
BUG_ON(image->size % PAGE_SIZE != 0);
for (i = 0; i < npages; i++)
image->text_mapping.pages[i] =
virt_to_page(image->data + i*PAGE_SIZE);
sechdrs = (void *)hdr + hdr->e_shoff;
secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (i = 1; i < hdr->e_shnum; i++) {
Elf32_Shdr *shdr = &sechdrs[i];
if (!strcmp(secstrings + shdr->sh_name, ".altinstructions")) {
alt_sec = shdr;
goto found;
}
}
/* If we get here, it's probably a bug. */
pr_warning("patch_vdso32: .altinstructions not found\n");
return; /* nothing to patch */
found:
alt_data = (void *)hdr + alt_sec->sh_offset;
apply_alternatives(alt_data, alt_data + alt_sec->sh_size);
apply_alternatives((struct alt_instr *)(image->data + image->alt),
(struct alt_instr *)(image->data + image->alt +
image->alt_len));
}
#endif
#if defined(CONFIG_X86_64)
static void __init patch_vdso64(void *vdso, size_t len)
{
Elf64_Ehdr *hdr = vdso;
Elf64_Shdr *sechdrs, *alt_sec = 0;
char *secstrings;
void *alt_data;
int i;
BUG_ON(len < sizeof(Elf64_Ehdr));
BUG_ON(memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0);
sechdrs = (void *)hdr + hdr->e_shoff;
secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (i = 1; i < hdr->e_shnum; i++) {
Elf64_Shdr *shdr = &sechdrs[i];
if (!strcmp(secstrings + shdr->sh_name, ".altinstructions")) {
alt_sec = shdr;
goto found;
}
}
/* If we get here, it's probably a bug. */
pr_warning("patch_vdso64: .altinstructions not found\n");
return; /* nothing to patch */
found:
alt_data = (void *)hdr + alt_sec->sh_offset;
apply_alternatives(alt_data, alt_data + alt_sec->sh_size);
}
static int __init init_vdso(void)
{
int npages = (vdso_end - vdso_start + PAGE_SIZE - 1) / PAGE_SIZE;
int i;
patch_vdso64(vdso_start, vdso_end - vdso_start);
vdso_size = npages << PAGE_SHIFT;
for (i = 0; i < npages; i++)
vdso_pages[i] = virt_to_page(vdso_start + i*PAGE_SIZE);
init_vdso_image(&vdso_image_64);
#ifdef CONFIG_X86_X32_ABI
patch_vdso32(vdsox32_start, vdsox32_end - vdsox32_start);
npages = (vdsox32_end - vdsox32_start + PAGE_SIZE - 1) / PAGE_SIZE;
vdsox32_size = npages << PAGE_SHIFT;
for (i = 0; i < npages; i++)
vdsox32_pages[i] = virt_to_page(vdsox32_start + i*PAGE_SIZE);
init_vdso_image(&vdso_image_x32);
#endif
return 0;
}
subsys_initcall(init_vdso);
#endif
struct linux_binprm;
/* Put the vdso above the (randomized) stack with another randomized offset.
This way there is no hole in the middle of address space.
To save memory make sure it is still in the same PTE as the stack top.
This doesn't give that many random bits */
This doesn't give that many random bits.
Only used for the 64-bit and x32 vdsos. */
static unsigned long vdso_addr(unsigned long start, unsigned len)
{
unsigned long addr, end;
@ -149,61 +85,149 @@ static unsigned long vdso_addr(unsigned long start, unsigned len)
return addr;
}
/* Setup a VMA at program startup for the vsyscall page.
Not called for compat tasks */
static int setup_additional_pages(struct linux_binprm *bprm,
int uses_interp,
struct page **pages,
unsigned size)
static int map_vdso(const struct vdso_image *image, bool calculate_addr)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long addr;
int ret;
int ret = 0;
static struct page *no_pages[] = {NULL};
static struct vm_special_mapping vvar_mapping = {
.name = "[vvar]",
.pages = no_pages,
};
if (!vdso_enabled)
return 0;
if (calculate_addr) {
addr = vdso_addr(current->mm->start_stack,
image->sym_end_mapping);
} else {
addr = 0;
}
down_write(&mm->mmap_sem);
addr = vdso_addr(mm->start_stack, size);
addr = get_unmapped_area(NULL, addr, size, 0, 0);
addr = get_unmapped_area(NULL, addr, image->sym_end_mapping, 0, 0);
if (IS_ERR_VALUE(addr)) {
ret = addr;
goto up_fail;
}
current->mm->context.vdso = (void *)addr;
current->mm->context.vdso = (void __user *)addr;
ret = install_special_mapping(mm, addr, size,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
pages);
if (ret) {
current->mm->context.vdso = NULL;
/*
* MAYWRITE to allow gdb to COW and set breakpoints
*/
vma = _install_special_mapping(mm,
addr,
image->size,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
&image->text_mapping);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto up_fail;
}
vma = _install_special_mapping(mm,
addr + image->size,
image->sym_end_mapping - image->size,
VM_READ,
&vvar_mapping);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto up_fail;
}
if (image->sym_vvar_page)
ret = remap_pfn_range(vma,
addr + image->sym_vvar_page,
__pa_symbol(&__vvar_page) >> PAGE_SHIFT,
PAGE_SIZE,
PAGE_READONLY);
if (ret)
goto up_fail;
#ifdef CONFIG_HPET_TIMER
if (hpet_address && image->sym_hpet_page) {
ret = io_remap_pfn_range(vma,
addr + image->sym_hpet_page,
hpet_address >> PAGE_SHIFT,
PAGE_SIZE,
pgprot_noncached(PAGE_READONLY));
if (ret)
goto up_fail;
}
#endif
up_fail:
if (ret)
current->mm->context.vdso = NULL;
up_write(&mm->mmap_sem);
return ret;
}
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
static int load_vdso32(void)
{
return setup_additional_pages(bprm, uses_interp, vdso_pages,
vdso_size);
}
int ret;
#ifdef CONFIG_X86_X32_ABI
int x32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
return setup_additional_pages(bprm, uses_interp, vdsox32_pages,
vdsox32_size);
if (vdso32_enabled != 1) /* Other values all mean "disabled" */
return 0;
ret = map_vdso(selected_vdso32, false);
if (ret)
return ret;
if (selected_vdso32->sym_VDSO32_SYSENTER_RETURN)
current_thread_info()->sysenter_return =
current->mm->context.vdso +
selected_vdso32->sym_VDSO32_SYSENTER_RETURN;
return 0;
}
#endif
#ifdef CONFIG_X86_64
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
if (!vdso64_enabled)
return 0;
return map_vdso(&vdso_image_64, true);
}
#ifdef CONFIG_COMPAT
int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
int uses_interp)
{
#ifdef CONFIG_X86_X32_ABI
if (test_thread_flag(TIF_X32)) {
if (!vdso64_enabled)
return 0;
return map_vdso(&vdso_image_x32, true);
}
#endif
return load_vdso32();
}
#endif
#else
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
return load_vdso32();
}
#endif
#ifdef CONFIG_X86_64
static __init int vdso_setup(char *s)
{
vdso_enabled = simple_strtoul(s, NULL, 0);
vdso64_enabled = simple_strtoul(s, NULL, 0);
return 0;
}
__setup("vdso=", vdso_setup);

8
arch/x86/xen/mmu.c
View File

@ -1494,7 +1494,7 @@ static int xen_pgd_alloc(struct mm_struct *mm)
page->private = (unsigned long)user_pgd;
if (user_pgd != NULL) {
user_pgd[pgd_index(VSYSCALL_START)] =
user_pgd[pgd_index(VSYSCALL_ADDR)] =
__pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
ret = 0;
}
@ -2062,8 +2062,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
case FIX_KMAP_BEGIN ... FIX_KMAP_END:
# endif
#else
case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE:
case VVAR_PAGE:
case VSYSCALL_PAGE:
#endif
case FIX_TEXT_POKE0:
case FIX_TEXT_POKE1:
@ -2104,8 +2103,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
#ifdef CONFIG_X86_64
/* Replicate changes to map the vsyscall page into the user
pagetable vsyscall mapping. */
if ((idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) ||
idx == VVAR_PAGE) {
if (idx == VSYSCALL_PAGE) {
unsigned long vaddr = __fix_to_virt(idx);
set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);
}

11
arch/x86/xen/setup.c
View File

@ -525,10 +525,17 @@ char * __init xen_memory_setup(void)
static void __init fiddle_vdso(void)
{
#ifdef CONFIG_X86_32
/*
* This could be called before selected_vdso32 is initialized, so
* just fiddle with both possible images. vdso_image_32_syscall
* can't be selected, since it only exists on 64-bit systems.
*/
u32 *mask;
mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK);
mask = vdso_image_32_int80.data +
vdso_image_32_int80.sym_VDSO32_NOTE_MASK;
*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK);
mask = vdso_image_32_sysenter.data +
vdso_image_32_sysenter.sym_VDSO32_NOTE_MASK;
*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
#endif
}

8
fs/binfmt_elf.c
View File

@ -1108,6 +1108,14 @@ static bool always_dump_vma(struct vm_area_struct *vma)
/* Any vsyscall mappings? */
if (vma == get_gate_vma(vma->vm_mm))
return true;
/*
* Assume that all vmas with a .name op should always be dumped.
* If this changes, a new vm_ops field can easily be added.
*/
if (vma->vm_ops && vma->vm_ops->name && vma->vm_ops->name(vma))
return true;
/*
* arch_vma_name() returns non-NULL for special architecture mappings,
* such as vDSO sections.

6
fs/proc/task_mmu.c
View File

@ -300,6 +300,12 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
goto done;
}
if (vma->vm_ops && vma->vm_ops->name) {
name = vma->vm_ops->name(vma);
if (name)
goto done;
}
name = arch_vma_name(vma);
if (!name) {
pid_t tid;

10
include/linux/mm.h
View File

@ -239,6 +239,12 @@ struct vm_operations_struct {
*/
int (*access)(struct vm_area_struct *vma, unsigned long addr,
void *buf, int len, int write);
/* Called by the /proc/PID/maps code to ask the vma whether it
* has a special name. Returning non-NULL will also cause this
* vma to be dumped unconditionally. */
const char *(*name)(struct vm_area_struct *vma);
#ifdef CONFIG_NUMA
/*
* set_policy() op must add a reference to any non-NULL @new mempolicy
@ -1783,7 +1789,9 @@ extern struct file *get_mm_exe_file(struct mm_struct *mm);
extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
extern struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
unsigned long addr, unsigned long len,
unsigned long flags, struct page **pages);
unsigned long flags,
const struct vm_special_mapping *spec);
/* This is an obsolete alternative to _install_special_mapping. */
extern int install_special_mapping(struct mm_struct *mm,
unsigned long addr, unsigned long len,
unsigned long flags, struct page **pages);

6
include/linux/mm_types.h
View File

@ -510,4 +510,10 @@ static inline void clear_tlb_flush_pending(struct mm_struct *mm)
}
#endif
struct vm_special_mapping
{
const char *name;
struct page **pages;
};
#endif /* _LINUX_MM_TYPES_H */

5
kernel/sysctl.c
View File

@ -1418,8 +1418,13 @@ static struct ctl_table vm_table[] = {
(defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
{
.procname = "vdso_enabled",
#ifdef CONFIG_X86_32
.data = &vdso32_enabled,
.maxlen = sizeof(vdso32_enabled),
#else
.data = &vdso_enabled,
.maxlen = sizeof(vdso_enabled),
#endif
.mode = 0644,
.proc_handler = proc_dointvec,
.extra1 = &zero,

89
mm/mmap.c
View File

@ -2871,6 +2871,31 @@ int may_expand_vm(struct mm_struct *mm, unsigned long npages)
return 1;
}
static int special_mapping_fault(struct vm_area_struct *vma,
struct vm_fault *vmf);
/*
* Having a close hook prevents vma merging regardless of flags.
*/
static void special_mapping_close(struct vm_area_struct *vma)
{
}
static const char *special_mapping_name(struct vm_area_struct *vma)
{
return ((struct vm_special_mapping *)vma->vm_private_data)->name;
}
static const struct vm_operations_struct special_mapping_vmops = {
.close = special_mapping_close,
.fault = special_mapping_fault,
.name = special_mapping_name,
};
static const struct vm_operations_struct legacy_special_mapping_vmops = {
.close = special_mapping_close,
.fault = special_mapping_fault,
};
static int special_mapping_fault(struct vm_area_struct *vma,
struct vm_fault *vmf)
@ -2886,7 +2911,13 @@ static int special_mapping_fault(struct vm_area_struct *vma,
*/
pgoff = vmf->pgoff - vma->vm_pgoff;
for (pages = vma->vm_private_data; pgoff && *pages; ++pages)
if (vma->vm_ops == &legacy_special_mapping_vmops)
pages = vma->vm_private_data;
else
pages = ((struct vm_special_mapping *)vma->vm_private_data)->
pages;
for (; pgoff && *pages; ++pages)
pgoff--;
if (*pages) {
@ -2899,30 +2930,11 @@ static int special_mapping_fault(struct vm_area_struct *vma,
return VM_FAULT_SIGBUS;
}
/*
* Having a close hook prevents vma merging regardless of flags.
*/
static void special_mapping_close(struct vm_area_struct *vma)
{
}
static const struct vm_operations_struct special_mapping_vmops = {
.close = special_mapping_close,
.fault = special_mapping_fault,
};
/*
* Called with mm->mmap_sem held for writing.
* Insert a new vma covering the given region, with the given flags.
* Its pages are supplied by the given array of struct page *.
* The array can be shorter than len >> PAGE_SHIFT if it's null-terminated.
* The region past the last page supplied will always produce SIGBUS.
* The array pointer and the pages it points to are assumed to stay alive
* for as long as this mapping might exist.
*/
struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
unsigned long addr, unsigned long len,
unsigned long vm_flags, struct page **pages)
static struct vm_area_struct *__install_special_mapping(
struct mm_struct *mm,
unsigned long addr, unsigned long len,
unsigned long vm_flags, const struct vm_operations_struct *ops,
void *priv)
{
int ret;
struct vm_area_struct *vma;
@ -2939,8 +2951,8 @@ struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
vma->vm_flags = vm_flags | mm->def_flags | VM_DONTEXPAND | VM_SOFTDIRTY;
vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
vma->vm_ops = &special_mapping_vmops;
vma->vm_private_data = pages;
vma->vm_ops = ops;
vma->vm_private_data = priv;
ret = insert_vm_struct(mm, vma);
if (ret)
@ -2957,12 +2969,31 @@ out:
return ERR_PTR(ret);
}
/*
* Called with mm->mmap_sem held for writing.
* Insert a new vma covering the given region, with the given flags.
* Its pages are supplied by the given array of struct page *.
* The array can be shorter than len >> PAGE_SHIFT if it's null-terminated.
* The region past the last page supplied will always produce SIGBUS.
* The array pointer and the pages it points to are assumed to stay alive
* for as long as this mapping might exist.
*/
struct vm_area_struct *_install_special_mapping(
struct mm_struct *mm,
unsigned long addr, unsigned long len,
unsigned long vm_flags, const struct vm_special_mapping *spec)
{
return __install_special_mapping(mm, addr, len, vm_flags,
&special_mapping_vmops, (void *)spec);
}
int install_special_mapping(struct mm_struct *mm,
unsigned long addr, unsigned long len,
unsigned long vm_flags, struct page **pages)
{
struct vm_area_struct *vma = _install_special_mapping(mm,
addr, len, vm_flags, pages);
struct vm_area_struct *vma = __install_special_mapping(
mm, addr, len, vm_flags, &legacy_special_mapping_vmops,
(void *)pages);
return PTR_ERR_OR_ZERO(vma);
}