kernel-ark/include/asm-i386/elf.h
Jeremy Fitzhardinge d4f7a2c18e [PATCH] i386: Relocate VDSO ELF headers to match mapped location with COMPAT_VDSO
Some versions of libc can't deal with a VDSO which doesn't have its
ELF headers matching its mapped address.  COMPAT_VDSO maps the VDSO at
a specific system-wide fixed address.  Previously this was all done at
build time, on the grounds that the fixed VDSO address is always at
the top of the address space.  However, a hypervisor may reserve some
of that address space, pushing the fixmap address down.

This patch does the adjustment dynamically at runtime, depending on
the runtime location of the VDSO fixmap.

[ Patch has been through several hands: Jan Beulich wrote the orignal
  version; Zach reworked it, and Jeremy converted it to relocate phdrs
  as well as sections. ]

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Zachary Amsden <zach@vmware.com>
Cc: "Jan Beulich" <JBeulich@novell.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
2007-05-02 19:27:12 +02:00

166 lines
5.0 KiB
C

#ifndef __ASMi386_ELF_H
#define __ASMi386_ELF_H
/*
* ELF register definitions..
*/
#include <asm/ptrace.h>
#include <asm/user.h>
#include <asm/auxvec.h>
#include <linux/utsname.h>
#define R_386_NONE 0
#define R_386_32 1
#define R_386_PC32 2
#define R_386_GOT32 3
#define R_386_PLT32 4
#define R_386_COPY 5
#define R_386_GLOB_DAT 6
#define R_386_JMP_SLOT 7
#define R_386_RELATIVE 8
#define R_386_GOTOFF 9
#define R_386_GOTPC 10
#define R_386_NUM 11
typedef unsigned long elf_greg_t;
#define ELF_NGREG (sizeof (struct user_regs_struct) / sizeof(elf_greg_t))
typedef elf_greg_t elf_gregset_t[ELF_NGREG];
typedef struct user_i387_struct elf_fpregset_t;
typedef struct user_fxsr_struct elf_fpxregset_t;
/*
* This is used to ensure we don't load something for the wrong architecture.
*/
#define elf_check_arch(x) \
(((x)->e_machine == EM_386) || ((x)->e_machine == EM_486))
/*
* These are used to set parameters in the core dumps.
*/
#define ELF_CLASS ELFCLASS32
#define ELF_DATA ELFDATA2LSB
#define ELF_ARCH EM_386
#ifdef __KERNEL__
#include <asm/processor.h>
#include <asm/system.h> /* for savesegment */
#include <asm/desc.h>
/* SVR4/i386 ABI (pages 3-31, 3-32) says that when the program starts %edx
contains a pointer to a function which might be registered using `atexit'.
This provides a mean for the dynamic linker to call DT_FINI functions for
shared libraries that have been loaded before the code runs.
A value of 0 tells we have no such handler.
We might as well make sure everything else is cleared too (except for %esp),
just to make things more deterministic.
*/
#define ELF_PLAT_INIT(_r, load_addr) do { \
_r->ebx = 0; _r->ecx = 0; _r->edx = 0; \
_r->esi = 0; _r->edi = 0; _r->ebp = 0; \
_r->eax = 0; \
} while (0)
#define USE_ELF_CORE_DUMP
#define ELF_EXEC_PAGESIZE 4096
/* This is the location that an ET_DYN program is loaded if exec'ed. Typical
use of this is to invoke "./ld.so someprog" to test out a new version of
the loader. We need to make sure that it is out of the way of the program
that it will "exec", and that there is sufficient room for the brk. */
#define ELF_ET_DYN_BASE (TASK_SIZE / 3 * 2)
/* regs is struct pt_regs, pr_reg is elf_gregset_t (which is
now struct_user_regs, they are different) */
#define ELF_CORE_COPY_REGS(pr_reg, regs) \
pr_reg[0] = regs->ebx; \
pr_reg[1] = regs->ecx; \
pr_reg[2] = regs->edx; \
pr_reg[3] = regs->esi; \
pr_reg[4] = regs->edi; \
pr_reg[5] = regs->ebp; \
pr_reg[6] = regs->eax; \
pr_reg[7] = regs->xds & 0xffff; \
pr_reg[8] = regs->xes & 0xffff; \
pr_reg[9] = regs->xfs & 0xffff; \
savesegment(gs,pr_reg[10]); \
pr_reg[11] = regs->orig_eax; \
pr_reg[12] = regs->eip; \
pr_reg[13] = regs->xcs & 0xffff; \
pr_reg[14] = regs->eflags; \
pr_reg[15] = regs->esp; \
pr_reg[16] = regs->xss & 0xffff;
/* This yields a mask that user programs can use to figure out what
instruction set this CPU supports. This could be done in user space,
but it's not easy, and we've already done it here. */
#define ELF_HWCAP (boot_cpu_data.x86_capability[0])
/* This yields a string that ld.so will use to load implementation
specific libraries for optimization. This is more specific in
intent than poking at uname or /proc/cpuinfo.
For the moment, we have only optimizations for the Intel generations,
but that could change... */
#define ELF_PLATFORM (utsname()->machine)
#define SET_PERSONALITY(ex, ibcs2) do { } while (0)
/*
* An executable for which elf_read_implies_exec() returns TRUE will
* have the READ_IMPLIES_EXEC personality flag set automatically.
*/
#define elf_read_implies_exec(ex, executable_stack) (executable_stack != EXSTACK_DISABLE_X)
struct task_struct;
extern int dump_task_regs (struct task_struct *, elf_gregset_t *);
extern int dump_task_fpu (struct task_struct *, elf_fpregset_t *);
extern int dump_task_extended_fpu (struct task_struct *, struct user_fxsr_struct *);
#define ELF_CORE_COPY_TASK_REGS(tsk, elf_regs) dump_task_regs(tsk, elf_regs)
#define ELF_CORE_COPY_FPREGS(tsk, elf_fpregs) dump_task_fpu(tsk, elf_fpregs)
#define ELF_CORE_COPY_XFPREGS(tsk, elf_xfpregs) dump_task_extended_fpu(tsk, elf_xfpregs)
#define VDSO_HIGH_BASE (__fix_to_virt(FIX_VDSO))
#define VDSO_CURRENT_BASE ((unsigned long)current->mm->context.vdso)
#define VDSO_PRELINK 0
#define VDSO_SYM(x) \
(VDSO_CURRENT_BASE + (unsigned long)(x) - VDSO_PRELINK)
#define VDSO_HIGH_EHDR ((const struct elfhdr *) VDSO_HIGH_BASE)
#define VDSO_EHDR ((const struct elfhdr *) VDSO_CURRENT_BASE)
extern void __kernel_vsyscall;
#define VDSO_ENTRY VDSO_SYM(&__kernel_vsyscall)
struct linux_binprm;
#define ARCH_HAS_SETUP_ADDITIONAL_PAGES
extern int arch_setup_additional_pages(struct linux_binprm *bprm,
int executable_stack);
extern unsigned int vdso_enabled;
#define ARCH_DLINFO \
do if (vdso_enabled) { \
NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY); \
NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE); \
} while (0)
#endif
#endif