arm64: dts: Revert "specify console via command line"
[linux/fpc-iii.git] / arch / arm / kernel / elf.c
blob18242298138621143f87a17c3c4ee059614eb329
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/export.h>
3 #include <linux/sched.h>
4 #include <linux/personality.h>
5 #include <linux/binfmts.h>
6 #include <linux/elf.h>
7 #include <linux/elf-fdpic.h>
8 #include <asm/system_info.h>
10 int elf_check_arch(const struct elf32_hdr *x)
12 unsigned int eflags;
14 /* Make sure it's an ARM executable */
15 if (x->e_machine != EM_ARM)
16 return 0;
18 /* Make sure the entry address is reasonable */
19 if (x->e_entry & 1) {
20 if (!(elf_hwcap & HWCAP_THUMB))
21 return 0;
22 } else if (x->e_entry & 3)
23 return 0;
25 eflags = x->e_flags;
26 if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN) {
27 unsigned int flt_fmt;
29 /* APCS26 is only allowed if the CPU supports it */
30 if ((eflags & EF_ARM_APCS_26) && !(elf_hwcap & HWCAP_26BIT))
31 return 0;
33 flt_fmt = eflags & (EF_ARM_VFP_FLOAT | EF_ARM_SOFT_FLOAT);
35 /* VFP requires the supporting code */
36 if (flt_fmt == EF_ARM_VFP_FLOAT && !(elf_hwcap & HWCAP_VFP))
37 return 0;
39 return 1;
41 EXPORT_SYMBOL(elf_check_arch);
43 void elf_set_personality(const struct elf32_hdr *x)
45 unsigned int eflags = x->e_flags;
46 unsigned int personality = current->personality & ~PER_MASK;
49 * We only support Linux ELF executables, so always set the
50 * personality to LINUX.
52 personality |= PER_LINUX;
55 * APCS-26 is only valid for OABI executables
57 if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN &&
58 (eflags & EF_ARM_APCS_26))
59 personality &= ~ADDR_LIMIT_32BIT;
60 else
61 personality |= ADDR_LIMIT_32BIT;
63 set_personality(personality);
66 * Since the FPA coprocessor uses CP1 and CP2, and iWMMXt uses CP0
67 * and CP1, we only enable access to the iWMMXt coprocessor if the
68 * binary is EABI or softfloat (and thus, guaranteed not to use
69 * FPA instructions.)
71 if (elf_hwcap & HWCAP_IWMMXT &&
72 eflags & (EF_ARM_EABI_MASK | EF_ARM_SOFT_FLOAT)) {
73 set_thread_flag(TIF_USING_IWMMXT);
74 } else {
75 clear_thread_flag(TIF_USING_IWMMXT);
78 EXPORT_SYMBOL(elf_set_personality);
81 * Set READ_IMPLIES_EXEC if:
82 * - the binary requires an executable stack
83 * - we're running on a CPU which doesn't support NX.
85 int arm_elf_read_implies_exec(int executable_stack)
87 if (executable_stack != EXSTACK_DISABLE_X)
88 return 1;
89 if (cpu_architecture() < CPU_ARCH_ARMv6)
90 return 1;
91 return 0;
93 EXPORT_SYMBOL(arm_elf_read_implies_exec);
95 #if defined(CONFIG_MMU) && defined(CONFIG_BINFMT_ELF_FDPIC)
97 void elf_fdpic_arch_lay_out_mm(struct elf_fdpic_params *exec_params,
98 struct elf_fdpic_params *interp_params,
99 unsigned long *start_stack,
100 unsigned long *start_brk)
102 elf_set_personality(&exec_params->hdr);
104 exec_params->load_addr = 0x8000;
105 interp_params->load_addr = ELF_ET_DYN_BASE;
106 *start_stack = TASK_SIZE - SZ_16M;
108 if ((exec_params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == ELF_FDPIC_FLAG_INDEPENDENT) {
109 exec_params->flags &= ~ELF_FDPIC_FLAG_ARRANGEMENT;
110 exec_params->flags |= ELF_FDPIC_FLAG_CONSTDISP;
114 #endif