linux_dsm_epyc7002/arch/arm/include/asm/elf.h
Nicolas Pitre ec706dab29 ARM: add a vma entry for the user accessible vector page
The kernel makes the high vector page visible to user space. This page
contains (amongst others) small code segments that can be executed in
user space.  Make this page visible through ptrace and /proc/<pid>/mem
in order to let gdb perform code parsing needed for proper unwinding.

For example, the ERESTART_RESTARTBLOCK handler actually has a stack
frame -- it returns to a PC value stored on the user's stack.   To
unwind after a "sleep" system call was interrupted twice, GDB would
have to recognize this situation and understand that stack frame
layout -- which it currently cannot do.

We could fix this by hard-coding addresses in the vector page range into
GDB, but that isn't really portable as not all of those addresses are
guaranteed to remain stable across kernel releases.  And having the gdb
process make an exception for this page and get  content from its own
address space for it looks strange, and it is not future proof either.

Being located above PAGE_OFFSET, this vma cannot be deleted by
user space code.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2010-10-01 22:35:19 -04:00

135 lines
4.2 KiB
C

#ifndef __ASMARM_ELF_H
#define __ASMARM_ELF_H
#include <asm/hwcap.h>
/*
* ELF register definitions..
*/
#include <asm/ptrace.h>
#include <asm/user.h>
struct task_struct;
typedef unsigned long elf_greg_t;
typedef unsigned long elf_freg_t[3];
#define ELF_NGREG (sizeof (struct pt_regs) / sizeof(elf_greg_t))
typedef elf_greg_t elf_gregset_t[ELF_NGREG];
typedef struct user_fp elf_fpregset_t;
#define EM_ARM 40
#define EF_ARM_EABI_MASK 0xff000000
#define EF_ARM_EABI_UNKNOWN 0x00000000
#define EF_ARM_EABI_VER1 0x01000000
#define EF_ARM_EABI_VER2 0x02000000
#define EF_ARM_EABI_VER3 0x03000000
#define EF_ARM_EABI_VER4 0x04000000
#define EF_ARM_EABI_VER5 0x05000000
#define EF_ARM_BE8 0x00800000 /* ABI 4,5 */
#define EF_ARM_LE8 0x00400000 /* ABI 4,5 */
#define EF_ARM_MAVERICK_FLOAT 0x00000800 /* ABI 0 */
#define EF_ARM_VFP_FLOAT 0x00000400 /* ABI 0 */
#define EF_ARM_SOFT_FLOAT 0x00000200 /* ABI 0 */
#define EF_ARM_OLD_ABI 0x00000100 /* ABI 0 */
#define EF_ARM_NEW_ABI 0x00000080 /* ABI 0 */
#define EF_ARM_ALIGN8 0x00000040 /* ABI 0 */
#define EF_ARM_PIC 0x00000020 /* ABI 0 */
#define EF_ARM_MAPSYMSFIRST 0x00000010 /* ABI 2 */
#define EF_ARM_APCS_FLOAT 0x00000010 /* ABI 0, floats in fp regs */
#define EF_ARM_DYNSYMSUSESEGIDX 0x00000008 /* ABI 2 */
#define EF_ARM_APCS_26 0x00000008 /* ABI 0 */
#define EF_ARM_SYMSARESORTED 0x00000004 /* ABI 1,2 */
#define EF_ARM_INTERWORK 0x00000004 /* ABI 0 */
#define EF_ARM_HASENTRY 0x00000002 /* All */
#define EF_ARM_RELEXEC 0x00000001 /* All */
#define R_ARM_NONE 0
#define R_ARM_PC24 1
#define R_ARM_ABS32 2
#define R_ARM_CALL 28
#define R_ARM_JUMP24 29
#define R_ARM_V4BX 40
#define R_ARM_PREL31 42
#define R_ARM_MOVW_ABS_NC 43
#define R_ARM_MOVT_ABS 44
#define R_ARM_THM_CALL 10
#define R_ARM_THM_JUMP24 30
#define R_ARM_THM_MOVW_ABS_NC 47
#define R_ARM_THM_MOVT_ABS 48
/*
* These are used to set parameters in the core dumps.
*/
#define ELF_CLASS ELFCLASS32
#ifdef __ARMEB__
#define ELF_DATA ELFDATA2MSB
#else
#define ELF_DATA ELFDATA2LSB
#endif
#define ELF_ARCH EM_ARM
/*
* 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 now we just provide a fairly general string that describes the
* processor family. This could be made more specific later if someone
* implemented optimisations that require it. 26-bit CPUs give you
* "v1l" for ARM2 (no SWP) and "v2l" for anything else (ARM1 isn't
* supported). 32-bit CPUs give you "v3[lb]" for anything based on an
* ARM6 or ARM7 core and "armv4[lb]" for anything based on a StrongARM-1
* core.
*/
#define ELF_PLATFORM_SIZE 8
#define ELF_PLATFORM (elf_platform)
extern char elf_platform[];
struct elf32_hdr;
/*
* This is used to ensure we don't load something for the wrong architecture.
*/
extern int elf_check_arch(const struct elf32_hdr *);
#define elf_check_arch elf_check_arch
extern int arm_elf_read_implies_exec(const struct elf32_hdr *, int);
#define elf_read_implies_exec(ex,stk) arm_elf_read_implies_exec(&(ex), stk)
struct task_struct;
int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs);
#define ELF_CORE_COPY_TASK_REGS dump_task_regs
#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 (2 * TASK_SIZE / 3)
/* When the program starts, a1 contains a pointer to a function to be
registered with atexit, as per the SVR4 ABI. A value of 0 means we
have no such handler. */
#define ELF_PLAT_INIT(_r, load_addr) (_r)->ARM_r0 = 0
extern void elf_set_personality(const struct elf32_hdr *);
#define SET_PERSONALITY(ex) elf_set_personality(&(ex))
struct mm_struct;
extern unsigned long arch_randomize_brk(struct mm_struct *mm);
#define arch_randomize_brk arch_randomize_brk
extern int vectors_user_mapping(void);
#define arch_setup_additional_pages(bprm, uses_interp) vectors_user_mapping()
#define ARCH_HAS_SETUP_ADDITIONAL_PAGES
#endif