[PATCH] vdso: randomize the i386 vDSO by moving it into a vma
[linux-2.6.git] / include / asm-i386 / elf.h
1 #ifndef __ASMi386_ELF_H
2 #define __ASMi386_ELF_H
3
4 /*
5  * ELF register definitions..
6  */
7
8 #include <asm/ptrace.h>
9 #include <asm/user.h>
10 #include <asm/processor.h>
11 #include <asm/system.h>         /* for savesegment */
12 #include <asm/auxvec.h>
13 #include <asm/desc.h>
14
15 #include <linux/utsname.h>
16
17 #define R_386_NONE      0
18 #define R_386_32        1
19 #define R_386_PC32      2
20 #define R_386_GOT32     3
21 #define R_386_PLT32     4
22 #define R_386_COPY      5
23 #define R_386_GLOB_DAT  6
24 #define R_386_JMP_SLOT  7
25 #define R_386_RELATIVE  8
26 #define R_386_GOTOFF    9
27 #define R_386_GOTPC     10
28 #define R_386_NUM       11
29
30 typedef unsigned long elf_greg_t;
31
32 #define ELF_NGREG (sizeof (struct user_regs_struct) / sizeof(elf_greg_t))
33 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
34
35 typedef struct user_i387_struct elf_fpregset_t;
36 typedef struct user_fxsr_struct elf_fpxregset_t;
37
38 /*
39  * This is used to ensure we don't load something for the wrong architecture.
40  */
41 #define elf_check_arch(x) \
42         (((x)->e_machine == EM_386) || ((x)->e_machine == EM_486))
43
44 /*
45  * These are used to set parameters in the core dumps.
46  */
47 #define ELF_CLASS       ELFCLASS32
48 #define ELF_DATA        ELFDATA2LSB
49 #define ELF_ARCH        EM_386
50
51 /* SVR4/i386 ABI (pages 3-31, 3-32) says that when the program starts %edx
52    contains a pointer to a function which might be registered using `atexit'.
53    This provides a mean for the dynamic linker to call DT_FINI functions for
54    shared libraries that have been loaded before the code runs.
55
56    A value of 0 tells we have no such handler. 
57
58    We might as well make sure everything else is cleared too (except for %esp),
59    just to make things more deterministic.
60  */
61 #define ELF_PLAT_INIT(_r, load_addr)    do { \
62         _r->ebx = 0; _r->ecx = 0; _r->edx = 0; \
63         _r->esi = 0; _r->edi = 0; _r->ebp = 0; \
64         _r->eax = 0; \
65 } while (0)
66
67 #define USE_ELF_CORE_DUMP
68 #define ELF_EXEC_PAGESIZE       4096
69
70 /* This is the location that an ET_DYN program is loaded if exec'ed.  Typical
71    use of this is to invoke "./ld.so someprog" to test out a new version of
72    the loader.  We need to make sure that it is out of the way of the program
73    that it will "exec", and that there is sufficient room for the brk.  */
74
75 #define ELF_ET_DYN_BASE         (TASK_SIZE / 3 * 2)
76
77 /* regs is struct pt_regs, pr_reg is elf_gregset_t (which is
78    now struct_user_regs, they are different) */
79
80 #define ELF_CORE_COPY_REGS(pr_reg, regs)                \
81         pr_reg[0] = regs->ebx;                          \
82         pr_reg[1] = regs->ecx;                          \
83         pr_reg[2] = regs->edx;                          \
84         pr_reg[3] = regs->esi;                          \
85         pr_reg[4] = regs->edi;                          \
86         pr_reg[5] = regs->ebp;                          \
87         pr_reg[6] = regs->eax;                          \
88         pr_reg[7] = regs->xds;                          \
89         pr_reg[8] = regs->xes;                          \
90         savesegment(fs,pr_reg[9]);                      \
91         savesegment(gs,pr_reg[10]);                     \
92         pr_reg[11] = regs->orig_eax;                    \
93         pr_reg[12] = regs->eip;                         \
94         pr_reg[13] = regs->xcs;                         \
95         pr_reg[14] = regs->eflags;                      \
96         pr_reg[15] = regs->esp;                         \
97         pr_reg[16] = regs->xss;
98
99 /* This yields a mask that user programs can use to figure out what
100    instruction set this CPU supports.  This could be done in user space,
101    but it's not easy, and we've already done it here.  */
102
103 #define ELF_HWCAP       (boot_cpu_data.x86_capability[0])
104
105 /* This yields a string that ld.so will use to load implementation
106    specific libraries for optimization.  This is more specific in
107    intent than poking at uname or /proc/cpuinfo.
108
109    For the moment, we have only optimizations for the Intel generations,
110    but that could change... */
111
112 #define ELF_PLATFORM  (system_utsname.machine)
113
114 #ifdef __KERNEL__
115 #define SET_PERSONALITY(ex, ibcs2) do { } while (0)
116
117 /*
118  * An executable for which elf_read_implies_exec() returns TRUE will
119  * have the READ_IMPLIES_EXEC personality flag set automatically.
120  */
121 #define elf_read_implies_exec(ex, executable_stack)     (executable_stack != EXSTACK_DISABLE_X)
122
123 struct task_struct;
124
125 extern int dump_task_regs (struct task_struct *, elf_gregset_t *);
126 extern int dump_task_fpu (struct task_struct *, elf_fpregset_t *);
127 extern int dump_task_extended_fpu (struct task_struct *, struct user_fxsr_struct *);
128
129 #define ELF_CORE_COPY_TASK_REGS(tsk, elf_regs) dump_task_regs(tsk, elf_regs)
130 #define ELF_CORE_COPY_FPREGS(tsk, elf_fpregs) dump_task_fpu(tsk, elf_fpregs)
131 #define ELF_CORE_COPY_XFPREGS(tsk, elf_xfpregs) dump_task_extended_fpu(tsk, elf_xfpregs)
132
133 #define VDSO_HIGH_BASE          (__fix_to_virt(FIX_VDSO))
134 #define VDSO_BASE               ((unsigned long)current->mm->context.vdso)
135
136 #ifdef CONFIG_COMPAT_VDSO
137 # define VDSO_COMPAT_BASE       VDSO_HIGH_BASE
138 # define VDSO_PRELINK           VDSO_HIGH_BASE
139 #else
140 # define VDSO_COMPAT_BASE       VDSO_BASE
141 # define VDSO_PRELINK           0
142 #endif
143
144 #define VDSO_COMPAT_SYM(x) \
145                 (VDSO_COMPAT_BASE + (unsigned long)(x) - VDSO_PRELINK)
146
147 #define VDSO_SYM(x) \
148                 (VDSO_BASE + (unsigned long)(x) - VDSO_PRELINK)
149
150 #define VDSO_HIGH_EHDR          ((const struct elfhdr *) VDSO_HIGH_BASE)
151 #define VDSO_EHDR               ((const struct elfhdr *) VDSO_COMPAT_BASE)
152
153 extern void __kernel_vsyscall;
154
155 #define VDSO_ENTRY              VDSO_SYM(&__kernel_vsyscall)
156
157 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES
158 struct linux_binprm;
159 extern int arch_setup_additional_pages(struct linux_binprm *bprm,
160                                        int executable_stack);
161
162 extern unsigned int vdso_enabled;
163
164 #define ARCH_DLINFO                                             \
165 do if (vdso_enabled) {                                          \
166                 NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY);            \
167                 NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_COMPAT_BASE); \
168 } while (0)
169
170 /*
171  * These macros parameterize elf_core_dump in fs/binfmt_elf.c to write out
172  * extra segments containing the vsyscall DSO contents.  Dumping its
173  * contents makes post-mortem fully interpretable later without matching up
174  * the same kernel and hardware config to see what PC values meant.
175  * Dumping its extra ELF program headers includes all the other information
176  * a debugger needs to easily find how the vsyscall DSO was being used.
177  */
178 #define ELF_CORE_EXTRA_PHDRS            (VDSO_HIGH_EHDR->e_phnum)
179 #define ELF_CORE_WRITE_EXTRA_PHDRS                                            \
180 do {                                                                          \
181         const struct elf_phdr *const vsyscall_phdrs =                         \
182                 (const struct elf_phdr *) (VDSO_HIGH_BASE                     \
183                                            + VDSO_HIGH_EHDR->e_phoff);    \
184         int i;                                                                \
185         Elf32_Off ofs = 0;                                                    \
186         for (i = 0; i < VDSO_HIGH_EHDR->e_phnum; ++i) {               \
187                 struct elf_phdr phdr = vsyscall_phdrs[i];                     \
188                 if (phdr.p_type == PT_LOAD) {                                 \
189                         BUG_ON(ofs != 0);                                     \
190                         ofs = phdr.p_offset = offset;                         \
191                         phdr.p_memsz = PAGE_ALIGN(phdr.p_memsz);              \
192                         phdr.p_filesz = phdr.p_memsz;                         \
193                         offset += phdr.p_filesz;                              \
194                 }                                                             \
195                 else                                                          \
196                         phdr.p_offset += ofs;                                 \
197                 phdr.p_paddr = 0; /* match other core phdrs */                \
198                 DUMP_WRITE(&phdr, sizeof(phdr));                              \
199         }                                                                     \
200 } while (0)
201 #define ELF_CORE_WRITE_EXTRA_DATA                                             \
202 do {                                                                          \
203         const struct elf_phdr *const vsyscall_phdrs =                         \
204                 (const struct elf_phdr *) (VDSO_HIGH_BASE                     \
205                                            + VDSO_HIGH_EHDR->e_phoff);    \
206         int i;                                                                \
207         for (i = 0; i < VDSO_HIGH_EHDR->e_phnum; ++i) {               \
208                 if (vsyscall_phdrs[i].p_type == PT_LOAD)                      \
209                         DUMP_WRITE((void *) vsyscall_phdrs[i].p_vaddr,        \
210                                    PAGE_ALIGN(vsyscall_phdrs[i].p_memsz));    \
211         }                                                                     \
212 } while (0)
213
214 #endif
215
216 #endif