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ac7b34218a
now that toolchains long support PT_GNU_STACK marking and there's no need anymore to force modern programs into having all its user mappings executable instead of only the stack and the PROT_EXEC ones. Disable that automatic READ_IMPLIES_EXEC forcing on x86-64 and arm64. Add tables documenting how READ_IMPLIES_EXEC is handled on x86-64, arm and arm64. By Kees Cook. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAl7YFDIACgkQEsHwGGHe VUpnzxAAmXdODNOb1gGQvt+KJthkfkWh2A2R+tWxCRmFtjFTcS/eRxFfvGu2KmFY 2b2AcJzuJeGjs7WIvQU0pkR2p6STyzuSBBLj5J/OJR9FonQ4pPah38df4A0fOgI6 GJyJV9Ie7O2Ph1w2iLOeWBdmR90CnYuabxsfipgOL+sjHlEI0RqLSDgARRQsxTEj KM+JVAFD472KcUJnQKBVBOD1I1DOVBGu12r3y6chgsOtwshLNW/cO15cDgYrgnJZ OlR3EIUukCEEc1KQzUCihsypLuGfrmdq1MyPN8CME8gLfmOBsJyGRDhvmdbS+Wxh kAMYQ9BuNP/jMVtN950qV0qUtnZCeIPlj1sDb9STWz5fInLsXDSCS0eYi32yBFi+ 7yviVU95ml6Mda1Qd5axItTHFAjKIn0qfMZszkLOtUszIzNinCgH7t3ThoXeV223 BqrpntRwiGZVpXDdcp0QFYBsWSMchR47yuhL8pB4SWxQzgNzXqAEg2KFQU0XMDKp pdia9IzUozg/BrjG5cnRfZhq2lBra7fy3Dn6fw5+NR5vqhka0Wr8L6dyM1Rj74EU HPk5bRXgt0OIiIFPi4139ApY7k+8j2nbf12qUchue1ZVVKzbvK996FDXbrGgW3zD Wis1wglxB9urSUTmC1bMOeyOd+gebo3i/ACAjgSo+EbDN7qW0Qw= =2L7y -----END PGP SIGNATURE----- Merge tag 'core_core_updates_for_5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull READ_IMPLIES_EXEC changes from Borislav Petkov: "Split the old READ_IMPLIES_EXEC workaround from executable PT_GNU_STACK now that toolchains long support PT_GNU_STACK marking and there's no need anymore to force modern programs into having all its user mappings executable instead of only the stack and the PROT_EXEC ones. Disable that automatic READ_IMPLIES_EXEC forcing on x86-64 and arm64. Add tables documenting how READ_IMPLIES_EXEC is handled on x86-64, arm and arm64. By Kees Cook" * tag 'core_core_updates_for_5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: arm64/elf: Disable automatic READ_IMPLIES_EXEC for 64-bit address spaces arm32/64/elf: Split READ_IMPLIES_EXEC from executable PT_GNU_STACK arm32/64/elf: Add tables to document READ_IMPLIES_EXEC x86/elf: Disable automatic READ_IMPLIES_EXEC on 64-bit x86/elf: Split READ_IMPLIES_EXEC from executable PT_GNU_STACK x86/elf: Add table to document READ_IMPLIES_EXEC
301 lines
8.0 KiB
C
301 lines
8.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2012 ARM Ltd.
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*/
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#ifndef __ASM_ELF_H
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#define __ASM_ELF_H
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#include <asm/hwcap.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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/*
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* AArch64 static relocation types.
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*/
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/* Miscellaneous. */
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#define R_ARM_NONE 0
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#define R_AARCH64_NONE 256
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/* Data. */
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#define R_AARCH64_ABS64 257
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#define R_AARCH64_ABS32 258
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#define R_AARCH64_ABS16 259
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#define R_AARCH64_PREL64 260
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#define R_AARCH64_PREL32 261
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#define R_AARCH64_PREL16 262
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/* Instructions. */
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#define R_AARCH64_MOVW_UABS_G0 263
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#define R_AARCH64_MOVW_UABS_G0_NC 264
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#define R_AARCH64_MOVW_UABS_G1 265
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#define R_AARCH64_MOVW_UABS_G1_NC 266
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#define R_AARCH64_MOVW_UABS_G2 267
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#define R_AARCH64_MOVW_UABS_G2_NC 268
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#define R_AARCH64_MOVW_UABS_G3 269
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#define R_AARCH64_MOVW_SABS_G0 270
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#define R_AARCH64_MOVW_SABS_G1 271
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#define R_AARCH64_MOVW_SABS_G2 272
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#define R_AARCH64_LD_PREL_LO19 273
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#define R_AARCH64_ADR_PREL_LO21 274
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#define R_AARCH64_ADR_PREL_PG_HI21 275
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#define R_AARCH64_ADR_PREL_PG_HI21_NC 276
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#define R_AARCH64_ADD_ABS_LO12_NC 277
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#define R_AARCH64_LDST8_ABS_LO12_NC 278
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#define R_AARCH64_TSTBR14 279
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#define R_AARCH64_CONDBR19 280
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#define R_AARCH64_JUMP26 282
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#define R_AARCH64_CALL26 283
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#define R_AARCH64_LDST16_ABS_LO12_NC 284
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#define R_AARCH64_LDST32_ABS_LO12_NC 285
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#define R_AARCH64_LDST64_ABS_LO12_NC 286
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#define R_AARCH64_LDST128_ABS_LO12_NC 299
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#define R_AARCH64_MOVW_PREL_G0 287
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#define R_AARCH64_MOVW_PREL_G0_NC 288
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#define R_AARCH64_MOVW_PREL_G1 289
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#define R_AARCH64_MOVW_PREL_G1_NC 290
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#define R_AARCH64_MOVW_PREL_G2 291
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#define R_AARCH64_MOVW_PREL_G2_NC 292
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#define R_AARCH64_MOVW_PREL_G3 293
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#define R_AARCH64_RELATIVE 1027
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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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#ifdef __AARCH64EB__
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#define ELF_DATA ELFDATA2MSB
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#else
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#define ELF_DATA ELFDATA2LSB
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#endif
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#define ELF_ARCH EM_AARCH64
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/*
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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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*/
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#define ELF_PLATFORM_SIZE 16
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#ifdef __AARCH64EB__
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#define ELF_PLATFORM ("aarch64_be")
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#else
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#define ELF_PLATFORM ("aarch64")
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#endif
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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) ((x)->e_machine == EM_AARCH64)
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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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* The decision process for determining the results are:
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*
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* CPU*: | arm32 | arm64 |
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* ELF: | | |
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* ---------------------|------------|------------|
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* missing PT_GNU_STACK | exec-all | exec-none |
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* PT_GNU_STACK == RWX | exec-stack | exec-stack |
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* PT_GNU_STACK == RW | exec-none | exec-none |
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*
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* exec-all : all PROT_READ user mappings are executable, except when
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* backed by files on a noexec-filesystem.
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* exec-none : only PROT_EXEC user mappings are executable.
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* exec-stack: only the stack and PROT_EXEC user mappings are executable.
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*
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* *all arm64 CPUs support NX, so there is no "lacks NX" column.
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*
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*/
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#define compat_elf_read_implies_exec(ex, stk) (stk == EXSTACK_DEFAULT)
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#define CORE_DUMP_USE_REGSET
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#define ELF_EXEC_PAGESIZE PAGE_SIZE
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/*
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* This is the base location for PIE (ET_DYN with INTERP) loads. On
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* 64-bit, this is above 4GB to leave the entire 32-bit address
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* space open for things that want to use the area for 32-bit pointers.
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*/
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#ifdef CONFIG_ARM64_FORCE_52BIT
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#define ELF_ET_DYN_BASE (2 * TASK_SIZE_64 / 3)
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#else
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#define ELF_ET_DYN_BASE (2 * DEFAULT_MAP_WINDOW_64 / 3)
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#endif /* CONFIG_ARM64_FORCE_52BIT */
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#ifndef __ASSEMBLY__
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#include <uapi/linux/elf.h>
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#include <linux/bug.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/types.h>
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#include <asm/processor.h> /* for signal_minsigstksz, used by ARCH_DLINFO */
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typedef unsigned long elf_greg_t;
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#define ELF_NGREG (sizeof(struct user_pt_regs) / sizeof(elf_greg_t))
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#define ELF_CORE_COPY_REGS(dest, regs) \
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*(struct user_pt_regs *)&(dest) = (regs)->user_regs;
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typedef elf_greg_t elf_gregset_t[ELF_NGREG];
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typedef struct user_fpsimd_state elf_fpregset_t;
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/*
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* When the program starts, a1 contains a pointer to a function to be
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* registered with atexit, as per the SVR4 ABI. A value of 0 means we have no
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* such handler.
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*/
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#define ELF_PLAT_INIT(_r, load_addr) (_r)->regs[0] = 0
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#define SET_PERSONALITY(ex) \
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({ \
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clear_thread_flag(TIF_32BIT); \
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current->personality &= ~READ_IMPLIES_EXEC; \
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})
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/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
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#define ARCH_DLINFO \
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do { \
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NEW_AUX_ENT(AT_SYSINFO_EHDR, \
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(elf_addr_t)current->mm->context.vdso); \
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\
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/* \
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* Should always be nonzero unless there's a kernel bug. \
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* If we haven't determined a sensible value to give to \
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* userspace, omit the entry: \
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*/ \
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if (likely(signal_minsigstksz)) \
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NEW_AUX_ENT(AT_MINSIGSTKSZ, signal_minsigstksz); \
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else \
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NEW_AUX_ENT(AT_IGNORE, 0); \
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} while (0)
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#define ARCH_HAS_SETUP_ADDITIONAL_PAGES
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struct linux_binprm;
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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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/* 1GB of VA */
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#ifdef CONFIG_COMPAT
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#define STACK_RND_MASK (test_thread_flag(TIF_32BIT) ? \
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0x7ff >> (PAGE_SHIFT - 12) : \
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0x3ffff >> (PAGE_SHIFT - 12))
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#else
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#define STACK_RND_MASK (0x3ffff >> (PAGE_SHIFT - 12))
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#endif
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#ifdef __AARCH64EB__
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#define COMPAT_ELF_PLATFORM ("v8b")
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#else
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#define COMPAT_ELF_PLATFORM ("v8l")
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#endif
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#ifdef CONFIG_COMPAT
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/* PIE load location for compat arm. Must match ARM ELF_ET_DYN_BASE. */
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#define COMPAT_ELF_ET_DYN_BASE 0x000400000UL
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/* AArch32 registers. */
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#define COMPAT_ELF_NGREG 18
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typedef unsigned int compat_elf_greg_t;
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typedef compat_elf_greg_t compat_elf_gregset_t[COMPAT_ELF_NGREG];
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/* AArch32 EABI. */
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#define EF_ARM_EABI_MASK 0xff000000
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#define compat_elf_check_arch(x) (system_supports_32bit_el0() && \
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((x)->e_machine == EM_ARM) && \
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((x)->e_flags & EF_ARM_EABI_MASK))
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#define compat_start_thread compat_start_thread
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/*
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* Unlike the native SET_PERSONALITY macro, the compat version maintains
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* READ_IMPLIES_EXEC across an execve() since this is the behaviour on
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* arch/arm/.
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*/
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#define COMPAT_SET_PERSONALITY(ex) \
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({ \
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set_thread_flag(TIF_32BIT); \
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})
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#ifdef CONFIG_COMPAT_VDSO
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#define COMPAT_ARCH_DLINFO \
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do { \
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/* \
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* Note that we use Elf64_Off instead of elf_addr_t because \
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* elf_addr_t in compat is defined as Elf32_Addr and casting \
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* current->mm->context.vdso to it triggers a cast warning of \
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* cast from pointer to integer of different size. \
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*/ \
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NEW_AUX_ENT(AT_SYSINFO_EHDR, \
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(Elf64_Off)current->mm->context.vdso); \
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} while (0)
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#else
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#define COMPAT_ARCH_DLINFO
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#endif
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extern int aarch32_setup_additional_pages(struct linux_binprm *bprm,
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int uses_interp);
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#define compat_arch_setup_additional_pages \
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aarch32_setup_additional_pages
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#endif /* CONFIG_COMPAT */
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struct arch_elf_state {
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int flags;
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};
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#define ARM64_ELF_BTI (1 << 0)
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#define INIT_ARCH_ELF_STATE { \
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.flags = 0, \
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}
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static inline int arch_parse_elf_property(u32 type, const void *data,
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size_t datasz, bool compat,
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struct arch_elf_state *arch)
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{
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/* No known properties for AArch32 yet */
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if (IS_ENABLED(CONFIG_COMPAT) && compat)
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return 0;
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if (type == GNU_PROPERTY_AARCH64_FEATURE_1_AND) {
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const u32 *p = data;
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if (datasz != sizeof(*p))
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return -ENOEXEC;
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if (system_supports_bti() &&
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(*p & GNU_PROPERTY_AARCH64_FEATURE_1_BTI))
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arch->flags |= ARM64_ELF_BTI;
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}
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return 0;
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}
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static inline int arch_elf_pt_proc(void *ehdr, void *phdr,
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struct file *f, bool is_interp,
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struct arch_elf_state *state)
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{
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return 0;
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}
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static inline int arch_check_elf(void *ehdr, bool has_interp,
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void *interp_ehdr,
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struct arch_elf_state *state)
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{
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return 0;
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}
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#endif /* !__ASSEMBLY__ */
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#endif
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