elf.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ASM_X86_ELF_H
  3#define _ASM_X86_ELF_H
  4
  5/*
  6 * ELF register definitions..
  7 */
  8#include <linux/thread_info.h>
  9
 10#include <asm/ia32.h>
 11#include <asm/ptrace.h>
 12#include <asm/user.h>
 13#include <asm/auxvec.h>
 14#include <asm/fsgsbase.h>
 15
 16typedef unsigned long elf_greg_t;
 17
 18#define ELF_NGREG (sizeof(struct user_regs_struct) / sizeof(elf_greg_t))
 19typedef elf_greg_t elf_gregset_t[ELF_NGREG];
 20
 21typedef struct user_i387_struct elf_fpregset_t;
 22
 23#ifdef __i386__
 24
 25#define R_386_NONE	0
 26#define R_386_32	1
 27#define R_386_PC32	2
 28#define R_386_GOT32	3
 29#define R_386_PLT32	4
 30#define R_386_COPY	5
 31#define R_386_GLOB_DAT	6
 32#define R_386_JMP_SLOT	7
 33#define R_386_RELATIVE	8
 34#define R_386_GOTOFF	9
 35#define R_386_GOTPC	10
 36#define R_386_NUM	11
 37
 38/*
 39 * These are used to set parameters in the core dumps.
 40 */
 41#define ELF_CLASS	ELFCLASS32
 42#define ELF_DATA	ELFDATA2LSB
 43#define ELF_ARCH	EM_386
 44
 45#else
 46
 47/* x86-64 relocation types */
 48#define R_X86_64_NONE		0	/* No reloc */
 49#define R_X86_64_64		1	/* Direct 64 bit  */
 50#define R_X86_64_PC32		2	/* PC relative 32 bit signed */
 51#define R_X86_64_GOT32		3	/* 32 bit GOT entry */
 52#define R_X86_64_PLT32		4	/* 32 bit PLT address */
 53#define R_X86_64_COPY		5	/* Copy symbol at runtime */
 54#define R_X86_64_GLOB_DAT	6	/* Create GOT entry */
 55#define R_X86_64_JUMP_SLOT	7	/* Create PLT entry */
 56#define R_X86_64_RELATIVE	8	/* Adjust by program base */
 57#define R_X86_64_GOTPCREL	9	/* 32 bit signed pc relative offset to GOT */
 58#define R_X86_64_GOTPCRELX	41
 59#define R_X86_64_REX_GOTPCRELX	42
 60#define R_X86_64_32		10	/* Direct 32 bit zero extended */
 61#define R_X86_64_32S		11	/* Direct 32 bit sign extended */
 62#define R_X86_64_16		12	/* Direct 16 bit zero extended */
 63#define R_X86_64_PC16		13	/* 16 bit sign extended pc relative */
 64#define R_X86_64_8		14	/* Direct 8 bit sign extended  */
 65#define R_X86_64_PC8		15	/* 8 bit sign extended pc relative */
 66#define R_X86_64_PC64		24	/* Place relative 64-bit signed */
 67
 68/*
 69 * These are used to set parameters in the core dumps.
 70 */
 71#define ELF_CLASS	ELFCLASS64
 72#define ELF_DATA	ELFDATA2LSB
 73#define ELF_ARCH	EM_X86_64
 74
 75#endif
 76
 77#include <asm/vdso.h>
 78
 79extern unsigned int vdso64_enabled;
 80extern unsigned int vdso32_enabled;
 81
 82/*
 83 * This is used to ensure we don't load something for the wrong architecture.
 84 */
 85#define elf_check_arch_ia32(x) \
 86	(((x)->e_machine == EM_386) || ((x)->e_machine == EM_486))
 87
 88#include <asm/processor.h>
 89
 90#ifdef CONFIG_X86_32
 91#include <asm/desc.h>
 92
 93#define elf_check_arch(x)	elf_check_arch_ia32(x)
 94
 95/* SVR4/i386 ABI (pages 3-31, 3-32) says that when the program starts %edx
 96   contains a pointer to a function which might be registered using `atexit'.
 97   This provides a mean for the dynamic linker to call DT_FINI functions for
 98   shared libraries that have been loaded before the code runs.
 99
100   A value of 0 tells we have no such handler.
101
102   We might as well make sure everything else is cleared too (except for %esp),
103   just to make things more deterministic.
104 */
105#define ELF_PLAT_INIT(_r, load_addr)		\
106	do {					\
107	_r->bx = 0; _r->cx = 0; _r->dx = 0;	\
108	_r->si = 0; _r->di = 0; _r->bp = 0;	\
109	_r->ax = 0;				\
110} while (0)
111
112/*
113 * regs is struct pt_regs, pr_reg is elf_gregset_t (which is
114 * now struct_user_regs, they are different)
115 */
116
117#define ELF_CORE_COPY_REGS(pr_reg, regs)	\
118do {						\
119	pr_reg[0] = regs->bx;			\
120	pr_reg[1] = regs->cx;			\
121	pr_reg[2] = regs->dx;			\
122	pr_reg[3] = regs->si;			\
123	pr_reg[4] = regs->di;			\
124	pr_reg[5] = regs->bp;			\
125	pr_reg[6] = regs->ax;			\
126	pr_reg[7] = regs->ds;			\
127	pr_reg[8] = regs->es;			\
128	pr_reg[9] = regs->fs;			\
129	savesegment(gs, pr_reg[10]);		\
130	pr_reg[11] = regs->orig_ax;		\
131	pr_reg[12] = regs->ip;			\
132	pr_reg[13] = regs->cs;			\
133	pr_reg[14] = regs->flags;		\
134	pr_reg[15] = regs->sp;			\
135	pr_reg[16] = regs->ss;			\
136} while (0);
137
138#define ELF_PLATFORM	(utsname()->machine)
139#define set_personality_64bit()	do { } while (0)
140
141#else /* CONFIG_X86_32 */
142
143/*
144 * This is used to ensure we don't load something for the wrong architecture.
145 */
146#define elf_check_arch(x)			\
147	((x)->e_machine == EM_X86_64)
148
149#define compat_elf_check_arch(x)					\
150	((elf_check_arch_ia32(x) && ia32_enabled_verbose()) ||		\
151	 (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine == EM_X86_64))
152
153static inline void elf_common_init(struct thread_struct *t,
154				   struct pt_regs *regs, const u16 ds)
155{
156	/* ax gets execve's return value. */
157	/*regs->ax = */ regs->bx = regs->cx = regs->dx = 0;
158	regs->si = regs->di = regs->bp = 0;
159	regs->r8 = regs->r9 = regs->r10 = regs->r11 = 0;
160	regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
161	t->fsbase = t->gsbase = 0;
162	t->fsindex = t->gsindex = 0;
163	t->ds = t->es = ds;
164}
165
166#define ELF_PLAT_INIT(_r, load_addr)			\
167	elf_common_init(&current->thread, _r, 0)
168
169#define	COMPAT_ELF_PLAT_INIT(regs, load_addr)		\
170	elf_common_init(&current->thread, regs, __USER_DS)
171
172void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp, bool x32);
173#define COMPAT_START_THREAD(ex, regs, new_ip, new_sp)	\
174	compat_start_thread(regs, new_ip, new_sp, ex->e_machine == EM_X86_64)
175
176void set_personality_ia32(bool);
177#define COMPAT_SET_PERSONALITY(ex)			\
178	set_personality_ia32((ex).e_machine == EM_X86_64)
179
180#define COMPAT_ELF_PLATFORM			("i686")
181
182/*
183 * regs is struct pt_regs, pr_reg is elf_gregset_t (which is
184 * now struct_user_regs, they are different). Assumes current is the process
185 * getting dumped.
186 */
187
188#define ELF_CORE_COPY_REGS(pr_reg, regs)			\
189do {								\
190	unsigned v;						\
191	(pr_reg)[0] = (regs)->r15;				\
192	(pr_reg)[1] = (regs)->r14;				\
193	(pr_reg)[2] = (regs)->r13;				\
194	(pr_reg)[3] = (regs)->r12;				\
195	(pr_reg)[4] = (regs)->bp;				\
196	(pr_reg)[5] = (regs)->bx;				\
197	(pr_reg)[6] = (regs)->r11;				\
198	(pr_reg)[7] = (regs)->r10;				\
199	(pr_reg)[8] = (regs)->r9;				\
200	(pr_reg)[9] = (regs)->r8;				\
201	(pr_reg)[10] = (regs)->ax;				\
202	(pr_reg)[11] = (regs)->cx;				\
203	(pr_reg)[12] = (regs)->dx;				\
204	(pr_reg)[13] = (regs)->si;				\
205	(pr_reg)[14] = (regs)->di;				\
206	(pr_reg)[15] = (regs)->orig_ax;				\
207	(pr_reg)[16] = (regs)->ip;				\
208	(pr_reg)[17] = (regs)->cs;				\
209	(pr_reg)[18] = (regs)->flags;				\
210	(pr_reg)[19] = (regs)->sp;				\
211	(pr_reg)[20] = (regs)->ss;				\
212	(pr_reg)[21] = x86_fsbase_read_cpu();			\
213	(pr_reg)[22] = x86_gsbase_read_cpu_inactive();		\
214	asm("movl %%ds,%0" : "=r" (v)); (pr_reg)[23] = v;	\
215	asm("movl %%es,%0" : "=r" (v)); (pr_reg)[24] = v;	\
216	asm("movl %%fs,%0" : "=r" (v)); (pr_reg)[25] = v;	\
217	asm("movl %%gs,%0" : "=r" (v)); (pr_reg)[26] = v;	\
218} while (0);
219
220/* I'm not sure if we can use '-' here */
221#define ELF_PLATFORM       ("x86_64")
222extern void set_personality_64bit(void);
223extern int force_personality32;
224
225#endif /* !CONFIG_X86_32 */
226
227#define CORE_DUMP_USE_REGSET
228#define ELF_EXEC_PAGESIZE	4096
229
230/*
231 * This is the base location for PIE (ET_DYN with INTERP) loads. On
232 * 64-bit, this is above 4GB to leave the entire 32-bit address
233 * space open for things that want to use the area for 32-bit pointers.
234 */
235#define ELF_ET_DYN_BASE		(mmap_is_ia32() ? 0x000400000UL : \
236						  (DEFAULT_MAP_WINDOW / 3 * 2))
237
238/* This yields a mask that user programs can use to figure out what
239   instruction set this CPU supports.  This could be done in user space,
240   but it's not easy, and we've already done it here.  */
241
242#define ELF_HWCAP		(boot_cpu_data.x86_capability[CPUID_1_EDX])
243
244extern u32 elf_hwcap2;
245
246/*
247 * HWCAP2 supplies mask with kernel enabled CPU features, so that
248 * the application can discover that it can safely use them.
249 * The bits are defined in uapi/asm/hwcap2.h.
250 */
251#define ELF_HWCAP2		(elf_hwcap2)
252
253/* This yields a string that ld.so will use to load implementation
254   specific libraries for optimization.  This is more specific in
255   intent than poking at uname or /proc/cpuinfo.
256
257   For the moment, we have only optimizations for the Intel generations,
258   but that could change... */
259
260#define SET_PERSONALITY(ex) set_personality_64bit()
261
262/*
263 * An executable for which elf_read_implies_exec() returns TRUE will
264 * have the READ_IMPLIES_EXEC personality flag set automatically.
265 *
266 * The decision process for determining the results are:
267 *
268 *                 CPU: | lacks NX*  | has NX, ia32     | has NX, x86_64 |
269 * ELF:                 |            |                  |                |
270 * ---------------------|------------|------------------|----------------|
271 * missing PT_GNU_STACK | exec-all   | exec-all         | exec-none      |
272 * PT_GNU_STACK == RWX  | exec-stack | exec-stack       | exec-stack     |
273 * PT_GNU_STACK == RW   | exec-none  | exec-none        | exec-none      |
274 *
275 *  exec-all  : all PROT_READ user mappings are executable, except when
276 *              backed by files on a noexec-filesystem.
277 *  exec-none : only PROT_EXEC user mappings are executable.
278 *  exec-stack: only the stack and PROT_EXEC user mappings are executable.
279 *
280 *  *this column has no architectural effect: NX markings are ignored by
281 *   hardware, but may have behavioral effects when "wants X" collides with
282 *   "cannot be X" constraints in memory permission flags, as in
283 *   https://lkml.kernel.org/r/20190418055759.GA3155@mellanox.com
284 *
285 */
286#define elf_read_implies_exec(ex, executable_stack)	\
287	(mmap_is_ia32() && executable_stack == EXSTACK_DEFAULT)
288
289struct task_struct;
290
291#define	ARCH_DLINFO_IA32						\
292do {									\
293	if (VDSO_CURRENT_BASE) {					\
294		NEW_AUX_ENT(AT_SYSINFO,	VDSO_ENTRY);			\
295		NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE);	\
296	}								\
297	NEW_AUX_ENT(AT_MINSIGSTKSZ, get_sigframe_size());		\
298} while (0)
299
300/*
301 * True on X86_32 or when emulating IA32 on X86_64
302 */
303static inline int mmap_is_ia32(void)
304{
305	return IS_ENABLED(CONFIG_X86_32) ||
306	       (IS_ENABLED(CONFIG_COMPAT) &&
307		test_thread_flag(TIF_ADDR32));
308}
309
310extern unsigned long task_size_32bit(void);
311extern unsigned long task_size_64bit(int full_addr_space);
312extern unsigned long get_mmap_base(int is_legacy);
313extern bool mmap_address_hint_valid(unsigned long addr, unsigned long len);
314extern unsigned long get_sigframe_size(void);
315
316#ifdef CONFIG_X86_32
317
318#define __STACK_RND_MASK(is32bit) (0x7ff)
319#define STACK_RND_MASK (0x7ff)
320
321#define ARCH_DLINFO		ARCH_DLINFO_IA32
322
323/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
324
325#else /* CONFIG_X86_32 */
326
327/* 1GB for 64bit, 8MB for 32bit */
328#define __STACK_RND_MASK(is32bit) ((is32bit) ? 0x7ff : 0x3fffff)
329#define STACK_RND_MASK __STACK_RND_MASK(mmap_is_ia32())
330
331#define ARCH_DLINFO							\
332do {									\
333	if (vdso64_enabled)						\
334		NEW_AUX_ENT(AT_SYSINFO_EHDR,				\
335			    (unsigned long __force)current->mm->context.vdso); \
336	NEW_AUX_ENT(AT_MINSIGSTKSZ, get_sigframe_size());		\
337} while (0)
338
339/* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
340#define ARCH_DLINFO_X32							\
341do {									\
342	if (vdso64_enabled)						\
343		NEW_AUX_ENT(AT_SYSINFO_EHDR,				\
344			    (unsigned long __force)current->mm->context.vdso); \
345	NEW_AUX_ENT(AT_MINSIGSTKSZ, get_sigframe_size());		\
346} while (0)
347
348#define AT_SYSINFO		32
349
350#define COMPAT_ARCH_DLINFO						\
351if (exec->e_machine == EM_X86_64)					\
352	ARCH_DLINFO_X32;						\
353else if (IS_ENABLED(CONFIG_IA32_EMULATION))				\
354	ARCH_DLINFO_IA32
355
356#define COMPAT_ELF_ET_DYN_BASE	(TASK_UNMAPPED_BASE + 0x1000000)
357
358#endif /* !CONFIG_X86_32 */
359
360#define VDSO_CURRENT_BASE	((unsigned long)current->mm->context.vdso)
361
362#define VDSO_ENTRY							\
363	((unsigned long)current->mm->context.vdso +			\
364	 vdso_image_32.sym___kernel_vsyscall)
365
366struct linux_binprm;
367
368#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
369extern int arch_setup_additional_pages(struct linux_binprm *bprm,
370				       int uses_interp);
371extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
372					      int uses_interp, bool x32);
373#define COMPAT_ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter)	\
374	compat_arch_setup_additional_pages(bprm, interpreter,		\
375					   (ex->e_machine == EM_X86_64))
376
377extern bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs);
378
379/* Do not change the values. See get_align_mask() */
380enum align_flags {
381	ALIGN_VA_32	= BIT(0),
382	ALIGN_VA_64	= BIT(1),
383};
384
385struct va_alignment {
386	int flags;
387	unsigned long mask;
388	unsigned long bits;
389} ____cacheline_aligned;
390
391extern struct va_alignment va_align;
392#endif /* _ASM_X86_ELF_H */