ccbeed3a05
Impact: pt_regs changed, lazy gs handling made optional, add slight
overhead to SAVE_ALL, simplifies error_code path a bit
On x86_32, %gs hasn't been used by kernel and handled lazily. pt_regs
doesn't have place for it and gs is saved/loaded only when necessary.
In preparation for stack protector support, this patch makes lazy %gs
handling optional by doing the followings.
* Add CONFIG_X86_32_LAZY_GS and place for gs in pt_regs.
* Save and restore %gs along with other registers in entry_32.S unless
LAZY_GS. Note that this unfortunately adds "pushl $0" on SAVE_ALL
even when LAZY_GS. However, it adds no overhead to common exit path
and simplifies entry path with error code.
* Define different user_gs accessors depending on LAZY_GS and add
lazy_save_gs() and lazy_load_gs() which are noop if !LAZY_GS. The
lazy_*_gs() ops are used to save, load and clear %gs lazily.
* Define ELF_CORE_COPY_KERNEL_REGS() which always read %gs directly.
xen and lguest changes need to be verified.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
347 lines
9.7 KiB
C
347 lines
9.7 KiB
C
#ifndef _ASM_X86_ELF_H
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#define _ASM_X86_ELF_H
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/*
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* ELF register definitions..
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*/
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#include <asm/ptrace.h>
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#include <asm/user.h>
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#include <asm/auxvec.h>
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typedef unsigned long elf_greg_t;
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#define ELF_NGREG (sizeof(struct user_regs_struct) / sizeof(elf_greg_t))
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typedef elf_greg_t elf_gregset_t[ELF_NGREG];
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typedef struct user_i387_struct elf_fpregset_t;
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#ifdef __i386__
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typedef struct user_fxsr_struct elf_fpxregset_t;
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#define R_386_NONE 0
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#define R_386_32 1
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#define R_386_PC32 2
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#define R_386_GOT32 3
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#define R_386_PLT32 4
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#define R_386_COPY 5
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#define R_386_GLOB_DAT 6
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#define R_386_JMP_SLOT 7
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#define R_386_RELATIVE 8
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#define R_386_GOTOFF 9
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#define R_386_GOTPC 10
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#define R_386_NUM 11
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/*
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* These are used to set parameters in the core dumps.
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*/
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#define ELF_CLASS ELFCLASS32
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#define ELF_DATA ELFDATA2LSB
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#define ELF_ARCH EM_386
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#else
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/* x86-64 relocation types */
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#define R_X86_64_NONE 0 /* No reloc */
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#define R_X86_64_64 1 /* Direct 64 bit */
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#define R_X86_64_PC32 2 /* PC relative 32 bit signed */
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#define R_X86_64_GOT32 3 /* 32 bit GOT entry */
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#define R_X86_64_PLT32 4 /* 32 bit PLT address */
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#define R_X86_64_COPY 5 /* Copy symbol at runtime */
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#define R_X86_64_GLOB_DAT 6 /* Create GOT entry */
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#define R_X86_64_JUMP_SLOT 7 /* Create PLT entry */
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#define R_X86_64_RELATIVE 8 /* Adjust by program base */
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#define R_X86_64_GOTPCREL 9 /* 32 bit signed pc relative
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offset to GOT */
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#define R_X86_64_32 10 /* Direct 32 bit zero extended */
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#define R_X86_64_32S 11 /* Direct 32 bit sign extended */
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#define R_X86_64_16 12 /* Direct 16 bit zero extended */
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#define R_X86_64_PC16 13 /* 16 bit sign extended pc relative */
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#define R_X86_64_8 14 /* Direct 8 bit sign extended */
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#define R_X86_64_PC8 15 /* 8 bit sign extended pc relative */
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#define R_X86_64_NUM 16
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/*
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* These are used to set parameters in the core dumps.
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*/
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#define ELF_CLASS ELFCLASS64
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#define ELF_DATA ELFDATA2LSB
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#define ELF_ARCH EM_X86_64
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#endif
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#include <asm/vdso.h>
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extern unsigned int vdso_enabled;
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/*
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* This is used to ensure we don't load something for the wrong architecture.
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*/
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#define elf_check_arch_ia32(x) \
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(((x)->e_machine == EM_386) || ((x)->e_machine == EM_486))
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#include <asm/processor.h>
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#include <asm/system.h>
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#ifdef CONFIG_X86_32
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#include <asm/desc.h>
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#define elf_check_arch(x) elf_check_arch_ia32(x)
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/* SVR4/i386 ABI (pages 3-31, 3-32) says that when the program starts %edx
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contains a pointer to a function which might be registered using `atexit'.
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This provides a mean for the dynamic linker to call DT_FINI functions for
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shared libraries that have been loaded before the code runs.
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A value of 0 tells we have no such handler.
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We might as well make sure everything else is cleared too (except for %esp),
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just to make things more deterministic.
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*/
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#define ELF_PLAT_INIT(_r, load_addr) \
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do { \
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_r->bx = 0; _r->cx = 0; _r->dx = 0; \
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_r->si = 0; _r->di = 0; _r->bp = 0; \
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_r->ax = 0; \
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} while (0)
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/*
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* regs is struct pt_regs, pr_reg is elf_gregset_t (which is
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* now struct_user_regs, they are different)
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*/
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#define ELF_CORE_COPY_REGS_COMMON(pr_reg, regs) \
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do { \
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pr_reg[0] = regs->bx; \
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pr_reg[1] = regs->cx; \
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pr_reg[2] = regs->dx; \
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pr_reg[3] = regs->si; \
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pr_reg[4] = regs->di; \
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pr_reg[5] = regs->bp; \
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pr_reg[6] = regs->ax; \
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pr_reg[7] = regs->ds & 0xffff; \
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pr_reg[8] = regs->es & 0xffff; \
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pr_reg[9] = regs->fs & 0xffff; \
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pr_reg[11] = regs->orig_ax; \
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pr_reg[12] = regs->ip; \
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pr_reg[13] = regs->cs & 0xffff; \
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pr_reg[14] = regs->flags; \
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pr_reg[15] = regs->sp; \
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pr_reg[16] = regs->ss & 0xffff; \
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} while (0);
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#define ELF_CORE_COPY_REGS(pr_reg, regs) \
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do { \
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ELF_CORE_COPY_REGS_COMMON(pr_reg, regs);\
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pr_reg[10] = get_user_gs(regs); \
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} while (0);
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#define ELF_CORE_COPY_KERNEL_REGS(pr_reg, regs) \
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do { \
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ELF_CORE_COPY_REGS_COMMON(pr_reg, regs);\
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savesegment(gs, pr_reg[10]); \
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} while (0);
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#define ELF_PLATFORM (utsname()->machine)
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#define set_personality_64bit() do { } while (0)
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#else /* CONFIG_X86_32 */
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/*
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* This is used to ensure we don't load something for the wrong architecture.
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*/
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#define elf_check_arch(x) \
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((x)->e_machine == EM_X86_64)
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#define compat_elf_check_arch(x) elf_check_arch_ia32(x)
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static inline void start_ia32_thread(struct pt_regs *regs, u32 ip, u32 sp)
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{
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loadsegment(fs, 0);
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loadsegment(ds, __USER32_DS);
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loadsegment(es, __USER32_DS);
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load_gs_index(0);
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regs->ip = ip;
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regs->sp = sp;
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regs->flags = X86_EFLAGS_IF;
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regs->cs = __USER32_CS;
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regs->ss = __USER32_DS;
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}
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static inline void elf_common_init(struct thread_struct *t,
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struct pt_regs *regs, const u16 ds)
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{
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regs->ax = regs->bx = regs->cx = regs->dx = 0;
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regs->si = regs->di = regs->bp = 0;
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regs->r8 = regs->r9 = regs->r10 = regs->r11 = 0;
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regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
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t->fs = t->gs = 0;
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t->fsindex = t->gsindex = 0;
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t->ds = t->es = ds;
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}
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#define ELF_PLAT_INIT(_r, load_addr) \
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do { \
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elf_common_init(¤t->thread, _r, 0); \
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clear_thread_flag(TIF_IA32); \
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} while (0)
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#define COMPAT_ELF_PLAT_INIT(regs, load_addr) \
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elf_common_init(¤t->thread, regs, __USER_DS)
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#define compat_start_thread(regs, ip, sp) \
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do { \
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start_ia32_thread(regs, ip, sp); \
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set_fs(USER_DS); \
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} while (0)
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#define COMPAT_SET_PERSONALITY(ex) \
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do { \
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if (test_thread_flag(TIF_IA32)) \
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clear_thread_flag(TIF_ABI_PENDING); \
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else \
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set_thread_flag(TIF_ABI_PENDING); \
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current->personality |= force_personality32; \
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} while (0)
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#define COMPAT_ELF_PLATFORM ("i686")
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/*
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* regs is struct pt_regs, pr_reg is elf_gregset_t (which is
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* now struct_user_regs, they are different). Assumes current is the process
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* getting dumped.
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*/
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#define ELF_CORE_COPY_REGS(pr_reg, regs) \
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do { \
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unsigned v; \
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(pr_reg)[0] = (regs)->r15; \
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(pr_reg)[1] = (regs)->r14; \
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(pr_reg)[2] = (regs)->r13; \
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(pr_reg)[3] = (regs)->r12; \
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(pr_reg)[4] = (regs)->bp; \
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(pr_reg)[5] = (regs)->bx; \
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(pr_reg)[6] = (regs)->r11; \
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(pr_reg)[7] = (regs)->r10; \
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(pr_reg)[8] = (regs)->r9; \
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(pr_reg)[9] = (regs)->r8; \
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(pr_reg)[10] = (regs)->ax; \
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(pr_reg)[11] = (regs)->cx; \
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(pr_reg)[12] = (regs)->dx; \
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(pr_reg)[13] = (regs)->si; \
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(pr_reg)[14] = (regs)->di; \
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(pr_reg)[15] = (regs)->orig_ax; \
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(pr_reg)[16] = (regs)->ip; \
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(pr_reg)[17] = (regs)->cs; \
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(pr_reg)[18] = (regs)->flags; \
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(pr_reg)[19] = (regs)->sp; \
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(pr_reg)[20] = (regs)->ss; \
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(pr_reg)[21] = current->thread.fs; \
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(pr_reg)[22] = current->thread.gs; \
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asm("movl %%ds,%0" : "=r" (v)); (pr_reg)[23] = v; \
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asm("movl %%es,%0" : "=r" (v)); (pr_reg)[24] = v; \
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asm("movl %%fs,%0" : "=r" (v)); (pr_reg)[25] = v; \
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asm("movl %%gs,%0" : "=r" (v)); (pr_reg)[26] = v; \
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} while (0);
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/* I'm not sure if we can use '-' here */
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#define ELF_PLATFORM ("x86_64")
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extern void set_personality_64bit(void);
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extern unsigned int sysctl_vsyscall32;
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extern int force_personality32;
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#endif /* !CONFIG_X86_32 */
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#define CORE_DUMP_USE_REGSET
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#define USE_ELF_CORE_DUMP
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#define ELF_EXEC_PAGESIZE 4096
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/* This is the location that an ET_DYN program is loaded if exec'ed. Typical
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use of this is to invoke "./ld.so someprog" to test out a new version of
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the loader. We need to make sure that it is out of the way of the program
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that it will "exec", and that there is sufficient room for the brk. */
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#define ELF_ET_DYN_BASE (TASK_SIZE / 3 * 2)
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/* This yields a mask that user programs can use to figure out what
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instruction set this CPU supports. This could be done in user space,
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but it's not easy, and we've already done it here. */
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#define ELF_HWCAP (boot_cpu_data.x86_capability[0])
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/* This yields a string that ld.so will use to load implementation
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specific libraries for optimization. This is more specific in
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intent than poking at uname or /proc/cpuinfo.
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For the moment, we have only optimizations for the Intel generations,
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but that could change... */
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#define SET_PERSONALITY(ex) set_personality_64bit()
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/*
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* An executable for which elf_read_implies_exec() returns TRUE will
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* have the READ_IMPLIES_EXEC personality flag set automatically.
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*/
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#define elf_read_implies_exec(ex, executable_stack) \
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(executable_stack != EXSTACK_DISABLE_X)
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struct task_struct;
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#define ARCH_DLINFO_IA32(vdso_enabled) \
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do { \
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if (vdso_enabled) { \
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NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY); \
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NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE); \
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} \
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} while (0)
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#ifdef CONFIG_X86_32
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#define VDSO_HIGH_BASE (__fix_to_virt(FIX_VDSO))
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#define ARCH_DLINFO ARCH_DLINFO_IA32(vdso_enabled)
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/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
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#else /* CONFIG_X86_32 */
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#define VDSO_HIGH_BASE 0xffffe000U /* CONFIG_COMPAT_VDSO address */
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/* 1GB for 64bit, 8MB for 32bit */
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#define STACK_RND_MASK (test_thread_flag(TIF_IA32) ? 0x7ff : 0x3fffff)
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#define ARCH_DLINFO \
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do { \
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if (vdso_enabled) \
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NEW_AUX_ENT(AT_SYSINFO_EHDR, \
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(unsigned long)current->mm->context.vdso); \
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} while (0)
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#define AT_SYSINFO 32
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#define COMPAT_ARCH_DLINFO ARCH_DLINFO_IA32(sysctl_vsyscall32)
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#define COMPAT_ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE + 0x1000000)
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#endif /* !CONFIG_X86_32 */
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#define VDSO_CURRENT_BASE ((unsigned long)current->mm->context.vdso)
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#define VDSO_ENTRY \
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((unsigned long)VDSO32_SYMBOL(VDSO_CURRENT_BASE, vsyscall))
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struct linux_binprm;
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#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
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extern int arch_setup_additional_pages(struct linux_binprm *bprm,
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int uses_interp);
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extern int syscall32_setup_pages(struct linux_binprm *, int exstack);
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#define compat_arch_setup_additional_pages syscall32_setup_pages
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extern unsigned long arch_randomize_brk(struct mm_struct *mm);
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#define arch_randomize_brk arch_randomize_brk
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#endif /* _ASM_X86_ELF_H */
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