linux/arch/x86/ia32/ia32_binfmt.c
Roland McGrath af65d64845 x86 vDSO: consolidate vdso32
This makes x86_64's ia32 emulation support share the sources used in the
32-bit kernel for the 32-bit vDSO and much of its setup code.

The 32-bit vDSO mapping now behaves the same on x86_64 as on native 32-bit.
The abi.syscall32 sysctl on x86_64 now takes the same values that
vm.vdso_enabled takes on the 32-bit kernel.  That is, 1 means a randomized
vDSO location, 2 means the fixed old address.  The CONFIG_COMPAT_VDSO
option is now available to make this the default setting, the same meaning
it has for the 32-bit kernel.  (This does not affect the 64-bit vDSO.)

The argument vdso32=[012] can be used on both 32-bit and 64-bit kernels to
set this paramter at boot time.  The vdso=[012] argument still does this
same thing on the 32-bit kernel.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:43 +01:00

285 lines
7.1 KiB
C

/*
* Written 2000,2002 by Andi Kleen.
*
* Loosely based on the sparc64 and IA64 32bit emulation loaders.
* This tricks binfmt_elf.c into loading 32bit binaries using lots
* of ugly preprocessor tricks. Talk about very very poor man's inheritance.
*/
#include <linux/types.h>
#include <linux/stddef.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/compat.h>
#include <linux/string.h>
#include <linux/binfmts.h>
#include <linux/mm.h>
#include <linux/security.h>
#include <linux/elfcore-compat.h>
#include <asm/segment.h>
#include <asm/ptrace.h>
#include <asm/processor.h>
#include <asm/user32.h>
#include <asm/sigcontext32.h>
#include <asm/fpu32.h>
#include <asm/i387.h>
#include <asm/uaccess.h>
#include <asm/ia32.h>
#include <asm/vdso.h>
#undef ELF_ARCH
#undef ELF_CLASS
#define ELF_CLASS ELFCLASS32
#define ELF_ARCH EM_386
#undef elfhdr
#undef elf_phdr
#undef elf_note
#undef elf_addr_t
#define elfhdr elf32_hdr
#define elf_phdr elf32_phdr
#define elf_note elf32_note
#define elf_addr_t Elf32_Off
#define ELF_NAME "elf/i386"
#define AT_SYSINFO 32
#define AT_SYSINFO_EHDR 33
extern int sysctl_vsyscall32;
#undef ARCH_DLINFO
#define ARCH_DLINFO do { \
if (sysctl_vsyscall32) { \
NEW_AUX_ENT(AT_SYSINFO, (u32)VDSO_ENTRY); \
NEW_AUX_ENT(AT_SYSINFO_EHDR, (u32)VDSO_CURRENT_BASE); \
} \
} while(0)
struct file;
#define IA32_EMULATOR 1
#undef ELF_ET_DYN_BASE
#define ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE + 0x1000000)
#define jiffies_to_timeval(a,b) do { (b)->tv_usec = 0; (b)->tv_sec = (a)/HZ; }while(0)
#define _GET_SEG(x) \
({ __u32 seg; asm("movl %%" __stringify(x) ",%0" : "=r"(seg)); seg; })
/* Assumes current==process to be dumped */
#undef ELF_CORE_COPY_REGS
#define ELF_CORE_COPY_REGS(pr_reg, regs) \
pr_reg[0] = regs->rbx; \
pr_reg[1] = regs->rcx; \
pr_reg[2] = regs->rdx; \
pr_reg[3] = regs->rsi; \
pr_reg[4] = regs->rdi; \
pr_reg[5] = regs->rbp; \
pr_reg[6] = regs->rax; \
pr_reg[7] = _GET_SEG(ds); \
pr_reg[8] = _GET_SEG(es); \
pr_reg[9] = _GET_SEG(fs); \
pr_reg[10] = _GET_SEG(gs); \
pr_reg[11] = regs->orig_rax; \
pr_reg[12] = regs->rip; \
pr_reg[13] = regs->cs; \
pr_reg[14] = regs->eflags; \
pr_reg[15] = regs->rsp; \
pr_reg[16] = regs->ss;
#define elf_prstatus compat_elf_prstatus
#define elf_prpsinfo compat_elf_prpsinfo
#define elf_fpregset_t struct user_i387_ia32_struct
#define elf_fpxregset_t struct user32_fxsr_struct
#define user user32
#undef elf_read_implies_exec
#define elf_read_implies_exec(ex, executable_stack) (executable_stack != EXSTACK_DISABLE_X)
#define elf_core_copy_regs elf32_core_copy_regs
static inline void elf32_core_copy_regs(compat_elf_gregset_t *elfregs,
struct pt_regs *regs)
{
ELF_CORE_COPY_REGS((&elfregs->ebx), regs)
}
#define elf_core_copy_task_regs elf32_core_copy_task_regs
static inline int elf32_core_copy_task_regs(struct task_struct *t,
compat_elf_gregset_t* elfregs)
{
struct pt_regs *pp = task_pt_regs(t);
ELF_CORE_COPY_REGS((&elfregs->ebx), pp);
/* fix wrong segments */
elfregs->ds = t->thread.ds;
elfregs->fs = t->thread.fsindex;
elfregs->gs = t->thread.gsindex;
elfregs->es = t->thread.es;
return 1;
}
#define elf_core_copy_task_fpregs elf32_core_copy_task_fpregs
static inline int
elf32_core_copy_task_fpregs(struct task_struct *tsk, struct pt_regs *regs,
elf_fpregset_t *fpu)
{
struct _fpstate_ia32 *fpstate = (void*)fpu;
mm_segment_t oldfs = get_fs();
if (!tsk_used_math(tsk))
return 0;
if (!regs)
regs = task_pt_regs(tsk);
if (tsk == current)
unlazy_fpu(tsk);
set_fs(KERNEL_DS);
save_i387_ia32(tsk, fpstate, regs, 1);
/* Correct for i386 bug. It puts the fop into the upper 16bits of
the tag word (like FXSAVE), not into the fcs*/
fpstate->cssel |= fpstate->tag & 0xffff0000;
set_fs(oldfs);
return 1;
}
#define ELF_CORE_COPY_XFPREGS 1
#define ELF_CORE_XFPREG_TYPE NT_PRXFPREG
#define elf_core_copy_task_xfpregs elf32_core_copy_task_xfpregs
static inline int
elf32_core_copy_task_xfpregs(struct task_struct *t, elf_fpxregset_t *xfpu)
{
struct pt_regs *regs = task_pt_regs(t);
if (!tsk_used_math(t))
return 0;
if (t == current)
unlazy_fpu(t);
memcpy(xfpu, &t->thread.i387.fxsave, sizeof(elf_fpxregset_t));
xfpu->fcs = regs->cs;
xfpu->fos = t->thread.ds; /* right? */
return 1;
}
#undef elf_check_arch
#define elf_check_arch(x) \
((x)->e_machine == EM_386)
extern int force_personality32;
#undef ELF_EXEC_PAGESIZE
#undef ELF_HWCAP
#undef ELF_PLATFORM
#undef SET_PERSONALITY
#define ELF_EXEC_PAGESIZE PAGE_SIZE
#define ELF_HWCAP (boot_cpu_data.x86_capability[0])
#define ELF_PLATFORM ("i686")
#define SET_PERSONALITY(ex, ibcs2) \
do { \
unsigned long new_flags = 0; \
if ((ex).e_ident[EI_CLASS] == ELFCLASS32) \
new_flags = _TIF_IA32; \
if ((current_thread_info()->flags & _TIF_IA32) \
!= new_flags) \
set_thread_flag(TIF_ABI_PENDING); \
else \
clear_thread_flag(TIF_ABI_PENDING); \
/* XXX This overwrites the user set personality */ \
current->personality |= force_personality32; \
} while (0)
/* Override some function names */
#define elf_format elf32_format
#define init_elf_binfmt init_elf32_binfmt
#define exit_elf_binfmt exit_elf32_binfmt
#define load_elf_binary load_elf32_binary
#undef ELF_PLAT_INIT
#define ELF_PLAT_INIT(r, load_addr) elf32_init(r)
#undef start_thread
#define start_thread(regs,new_rip,new_rsp) do { \
asm volatile("movl %0,%%fs" :: "r" (0)); \
asm volatile("movl %0,%%es; movl %0,%%ds": :"r" (__USER32_DS)); \
load_gs_index(0); \
(regs)->rip = (new_rip); \
(regs)->rsp = (new_rsp); \
(regs)->eflags = 0x200; \
(regs)->cs = __USER32_CS; \
(regs)->ss = __USER32_DS; \
set_fs(USER_DS); \
} while(0)
#include <linux/module.h>
MODULE_DESCRIPTION("Binary format loader for compatibility with IA32 ELF binaries.");
MODULE_AUTHOR("Eric Youngdale, Andi Kleen");
#undef MODULE_DESCRIPTION
#undef MODULE_AUTHOR
static void elf32_init(struct pt_regs *);
#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
#define arch_setup_additional_pages syscall32_setup_pages
extern int syscall32_setup_pages(struct linux_binprm *, int exstack);
#include "../../../fs/binfmt_elf.c"
static void elf32_init(struct pt_regs *regs)
{
struct task_struct *me = current;
regs->rdi = 0;
regs->rsi = 0;
regs->rdx = 0;
regs->rcx = 0;
regs->rax = 0;
regs->rbx = 0;
regs->rbp = 0;
regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
regs->r13 = regs->r14 = regs->r15 = 0;
me->thread.fs = 0;
me->thread.gs = 0;
me->thread.fsindex = 0;
me->thread.gsindex = 0;
me->thread.ds = __USER_DS;
me->thread.es = __USER_DS;
}
#ifdef CONFIG_SYSCTL
/* Register vsyscall32 into the ABI table */
#include <linux/sysctl.h>
static ctl_table abi_table2[] = {
{
.procname = "vsyscall32",
.data = &sysctl_vsyscall32,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{}
};
static ctl_table abi_root_table2[] = {
{
.ctl_name = CTL_ABI,
.procname = "abi",
.mode = 0555,
.child = abi_table2
},
{}
};
static __init int ia32_binfmt_init(void)
{
register_sysctl_table(abi_root_table2);
return 0;
}
__initcall(ia32_binfmt_init);
#endif