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Diffstat (limited to 'arch/x86/vdso/vdso32-setup.c')
-rw-r--r--arch/x86/vdso/vdso32-setup.c301
1 files changed, 81 insertions, 220 deletions
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index d6bfb876cfb0..00348980a3a6 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -16,6 +16,7 @@
#include <linux/mm.h>
#include <linux/err.h>
#include <linux/module.h>
+#include <linux/slab.h>
#include <asm/cpufeature.h>
#include <asm/msr.h>
@@ -25,17 +26,14 @@
#include <asm/tlbflush.h>
#include <asm/vdso.h>
#include <asm/proto.h>
-
-enum {
- VDSO_DISABLED = 0,
- VDSO_ENABLED = 1,
- VDSO_COMPAT = 2,
-};
+#include <asm/fixmap.h>
+#include <asm/hpet.h>
+#include <asm/vvar.h>
#ifdef CONFIG_COMPAT_VDSO
-#define VDSO_DEFAULT VDSO_COMPAT
+#define VDSO_DEFAULT 0
#else
-#define VDSO_DEFAULT VDSO_ENABLED
+#define VDSO_DEFAULT 1
#endif
#ifdef CONFIG_X86_64
@@ -44,13 +42,6 @@ enum {
#endif
/*
- * This is the difference between the prelinked addresses in the vDSO images
- * and the VDSO_HIGH_BASE address where CONFIG_COMPAT_VDSO places the vDSO
- * in the user address space.
- */
-#define VDSO_ADDR_ADJUST (VDSO_HIGH_BASE - (unsigned long)VDSO32_PRELINK)
-
-/*
* Should the kernel map a VDSO page into processes and pass its
* address down to glibc upon exec()?
*/
@@ -60,6 +51,9 @@ static int __init vdso_setup(char *s)
{
vdso_enabled = simple_strtoul(s, NULL, 0);
+ if (vdso_enabled > 1)
+ pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
+
return 1;
}
@@ -76,124 +70,8 @@ __setup_param("vdso=", vdso32_setup, vdso_setup, 0);
EXPORT_SYMBOL_GPL(vdso_enabled);
#endif
-static __init void reloc_symtab(Elf32_Ehdr *ehdr,
- unsigned offset, unsigned size)
-{
- Elf32_Sym *sym = (void *)ehdr + offset;
- unsigned nsym = size / sizeof(*sym);
- unsigned i;
-
- for(i = 0; i < nsym; i++, sym++) {
- if (sym->st_shndx == SHN_UNDEF ||
- sym->st_shndx == SHN_ABS)
- continue; /* skip */
-
- if (sym->st_shndx > SHN_LORESERVE) {
- printk(KERN_INFO "VDSO: unexpected st_shndx %x\n",
- sym->st_shndx);
- continue;
- }
-
- switch(ELF_ST_TYPE(sym->st_info)) {
- case STT_OBJECT:
- case STT_FUNC:
- case STT_SECTION:
- case STT_FILE:
- sym->st_value += VDSO_ADDR_ADJUST;
- }
- }
-}
-
-static __init void reloc_dyn(Elf32_Ehdr *ehdr, unsigned offset)
-{
- Elf32_Dyn *dyn = (void *)ehdr + offset;
-
- for(; dyn->d_tag != DT_NULL; dyn++)
- switch(dyn->d_tag) {
- case DT_PLTGOT:
- case DT_HASH:
- case DT_STRTAB:
- case DT_SYMTAB:
- case DT_RELA:
- case DT_INIT:
- case DT_FINI:
- case DT_REL:
- case DT_DEBUG:
- case DT_JMPREL:
- case DT_VERSYM:
- case DT_VERDEF:
- case DT_VERNEED:
- case DT_ADDRRNGLO ... DT_ADDRRNGHI:
- /* definitely pointers needing relocation */
- dyn->d_un.d_ptr += VDSO_ADDR_ADJUST;
- break;
-
- case DT_ENCODING ... OLD_DT_LOOS-1:
- case DT_LOOS ... DT_HIOS-1:
- /* Tags above DT_ENCODING are pointers if
- they're even */
- if (dyn->d_tag >= DT_ENCODING &&
- (dyn->d_tag & 1) == 0)
- dyn->d_un.d_ptr += VDSO_ADDR_ADJUST;
- break;
-
- case DT_VERDEFNUM:
- case DT_VERNEEDNUM:
- case DT_FLAGS_1:
- case DT_RELACOUNT:
- case DT_RELCOUNT:
- case DT_VALRNGLO ... DT_VALRNGHI:
- /* definitely not pointers */
- break;
-
- case OLD_DT_LOOS ... DT_LOOS-1:
- case DT_HIOS ... DT_VALRNGLO-1:
- default:
- if (dyn->d_tag > DT_ENCODING)
- printk(KERN_INFO "VDSO: unexpected DT_tag %x\n",
- dyn->d_tag);
- break;
- }
-}
-
-static __init void relocate_vdso(Elf32_Ehdr *ehdr)
-{
- Elf32_Phdr *phdr;
- Elf32_Shdr *shdr;
- int i;
-
- BUG_ON(memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0 ||
- !elf_check_arch_ia32(ehdr) ||
- ehdr->e_type != ET_DYN);
-
- ehdr->e_entry += VDSO_ADDR_ADJUST;
-
- /* rebase phdrs */
- phdr = (void *)ehdr + ehdr->e_phoff;
- for (i = 0; i < ehdr->e_phnum; i++) {
- phdr[i].p_vaddr += VDSO_ADDR_ADJUST;
-
- /* relocate dynamic stuff */
- if (phdr[i].p_type == PT_DYNAMIC)
- reloc_dyn(ehdr, phdr[i].p_offset);
- }
-
- /* rebase sections */
- shdr = (void *)ehdr + ehdr->e_shoff;
- for(i = 0; i < ehdr->e_shnum; i++) {
- if (!(shdr[i].sh_flags & SHF_ALLOC))
- continue;
-
- shdr[i].sh_addr += VDSO_ADDR_ADJUST;
-
- if (shdr[i].sh_type == SHT_SYMTAB ||
- shdr[i].sh_type == SHT_DYNSYM)
- reloc_symtab(ehdr, shdr[i].sh_offset,
- shdr[i].sh_size);
- }
-}
-
-static struct page *vdso32_pages[1];
+static struct page **vdso32_pages;
+static unsigned vdso32_size;
#ifdef CONFIG_X86_64
@@ -212,12 +90,6 @@ void syscall32_cpu_init(void)
wrmsrl(MSR_CSTAR, ia32_cstar_target);
}
-#define compat_uses_vma 1
-
-static inline void map_compat_vdso(int map)
-{
-}
-
#else /* CONFIG_X86_32 */
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SEP))
@@ -241,64 +113,36 @@ void enable_sep_cpu(void)
put_cpu();
}
-static struct vm_area_struct gate_vma;
-
-static int __init gate_vma_init(void)
-{
- gate_vma.vm_mm = NULL;
- gate_vma.vm_start = FIXADDR_USER_START;
- gate_vma.vm_end = FIXADDR_USER_END;
- gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
- gate_vma.vm_page_prot = __P101;
-
- return 0;
-}
-
-#define compat_uses_vma 0
-
-static void map_compat_vdso(int map)
-{
- static int vdso_mapped;
-
- if (map == vdso_mapped)
- return;
-
- vdso_mapped = map;
-
- __set_fixmap(FIX_VDSO, page_to_pfn(vdso32_pages[0]) << PAGE_SHIFT,
- map ? PAGE_READONLY_EXEC : PAGE_NONE);
-
- /* flush stray tlbs */
- flush_tlb_all();
-}
-
#endif /* CONFIG_X86_64 */
int __init sysenter_setup(void)
{
- void *syscall_page = (void *)get_zeroed_page(GFP_ATOMIC);
- const void *vsyscall;
- size_t vsyscall_len;
-
- vdso32_pages[0] = virt_to_page(syscall_page);
-
-#ifdef CONFIG_X86_32
- gate_vma_init();
-#endif
+ char *vdso32_start, *vdso32_end;
+ int npages, i;
+#ifdef CONFIG_COMPAT
if (vdso32_syscall()) {
- vsyscall = &vdso32_syscall_start;
- vsyscall_len = &vdso32_syscall_end - &vdso32_syscall_start;
- } else if (vdso32_sysenter()){
- vsyscall = &vdso32_sysenter_start;
- vsyscall_len = &vdso32_sysenter_end - &vdso32_sysenter_start;
+ vdso32_start = vdso32_syscall_start;
+ vdso32_end = vdso32_syscall_end;
+ vdso32_pages = vdso32_syscall_pages;
+ } else
+#endif
+ if (vdso32_sysenter()) {
+ vdso32_start = vdso32_sysenter_start;
+ vdso32_end = vdso32_sysenter_end;
+ vdso32_pages = vdso32_sysenter_pages;
} else {
- vsyscall = &vdso32_int80_start;
- vsyscall_len = &vdso32_int80_end - &vdso32_int80_start;
+ vdso32_start = vdso32_int80_start;
+ vdso32_end = vdso32_int80_end;
+ vdso32_pages = vdso32_int80_pages;
}
- memcpy(syscall_page, vsyscall, vsyscall_len);
- relocate_vdso(syscall_page);
+ 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);
return 0;
}
@@ -309,48 +153,73 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
struct mm_struct *mm = current->mm;
unsigned long addr;
int ret = 0;
- bool compat;
+ 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 == VDSO_DISABLED)
+ if (vdso_enabled != 1) /* Other values all mean "disabled" */
return 0;
down_write(&mm->mmap_sem);
- /* Test compat mode once here, in case someone
- changes it via sysctl */
- compat = (vdso_enabled == VDSO_COMPAT);
+ 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);
- map_compat_vdso(compat);
+ current->mm->context.vdso = (void *)addr;
- if (compat)
- addr = VDSO_HIGH_BASE;
- else {
- addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
- if (IS_ERR_VALUE(addr)) {
- ret = addr;
- goto up_fail;
- }
+ /*
+ * 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;
}
- current->mm->context.vdso = (void *)addr;
+ 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;
- if (compat_uses_vma || !compat) {
- /*
- * MAYWRITE to allow gdb to COW and set breakpoints
- */
- ret = install_special_mapping(mm, addr, PAGE_SIZE,
- VM_READ|VM_EXEC|
- VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- vdso32_pages);
+#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);
@@ -411,20 +280,12 @@ const char *arch_vma_name(struct vm_area_struct *vma)
struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
- /*
- * Check to see if the corresponding task was created in compat vdso
- * mode.
- */
- if (mm && mm->context.vdso == (void *)VDSO_HIGH_BASE)
- return &gate_vma;
return NULL;
}
int in_gate_area(struct mm_struct *mm, unsigned long addr)
{
- const struct vm_area_struct *vma = get_gate_vma(mm);
-
- return vma && addr >= vma->vm_start && addr < vma->vm_end;
+ return 0;
}
int in_gate_area_no_mm(unsigned long addr)