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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>
9
10int elf_check_arch(const struct elf32_hdr *x)
11{
12 unsigned int eflags;
13
14 /* Make sure it's an ARM executable */
15 if (x->e_machine != EM_ARM)
16 return 0;
17
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;
24
25 eflags = x->e_flags;
26 if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN) {
27 unsigned int flt_fmt;
28
29 /* APCS26 is only allowed if the CPU supports it */
30 if ((eflags & EF_ARM_APCS_26) && !(elf_hwcap & HWCAP_26BIT))
31 return 0;
32
33 flt_fmt = eflags & (EF_ARM_VFP_FLOAT | EF_ARM_SOFT_FLOAT);
34
35 /* VFP requires the supporting code */
36 if (flt_fmt == EF_ARM_VFP_FLOAT && !(elf_hwcap & HWCAP_VFP))
37 return 0;
38 }
39 return 1;
40}
41EXPORT_SYMBOL(elf_check_arch);
42
43void elf_set_personality(const struct elf32_hdr *x)
44{
45 unsigned int eflags = x->e_flags;
46 unsigned int personality = current->personality & ~PER_MASK;
47
48 /*
49 * We only support Linux ELF executables, so always set the
50 * personality to LINUX.
51 */
52 personality |= PER_LINUX;
53
54 /*
55 * APCS-26 is only valid for OABI executables
56 */
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;
62
63 set_personality(personality);
64
65 /*
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.)
70 */
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);
76 }
77}
78EXPORT_SYMBOL(elf_set_personality);
79
80/*
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.
84 */
85int arm_elf_read_implies_exec(int executable_stack)
86{
87 if (executable_stack != EXSTACK_DISABLE_X)
88 return 1;
89 if (cpu_architecture() < CPU_ARCH_ARMv6)
90 return 1;
91 return 0;
92}
93EXPORT_SYMBOL(arm_elf_read_implies_exec);
94
95#if defined(CONFIG_MMU) && defined(CONFIG_BINFMT_ELF_FDPIC)
96
97void 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)
101{
102 elf_set_personality(&exec_params->hdr);
103
104 exec_params->load_addr = 0x8000;
105 interp_params->load_addr = ELF_ET_DYN_BASE;
106 *start_stack = TASK_SIZE - SZ_16M;
107
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;
111 }
112}
113
114#endif
1#include <linux/module.h>
2#include <linux/sched.h>
3#include <linux/personality.h>
4#include <linux/binfmts.h>
5#include <linux/elf.h>
6
7int elf_check_arch(const struct elf32_hdr *x)
8{
9 unsigned int eflags;
10
11 /* Make sure it's an ARM executable */
12 if (x->e_machine != EM_ARM)
13 return 0;
14
15 /* Make sure the entry address is reasonable */
16 if (x->e_entry & 1) {
17 if (!(elf_hwcap & HWCAP_THUMB))
18 return 0;
19 } else if (x->e_entry & 3)
20 return 0;
21
22 eflags = x->e_flags;
23 if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN) {
24 unsigned int flt_fmt;
25
26 /* APCS26 is only allowed if the CPU supports it */
27 if ((eflags & EF_ARM_APCS_26) && !(elf_hwcap & HWCAP_26BIT))
28 return 0;
29
30 flt_fmt = eflags & (EF_ARM_VFP_FLOAT | EF_ARM_SOFT_FLOAT);
31
32 /* VFP requires the supporting code */
33 if (flt_fmt == EF_ARM_VFP_FLOAT && !(elf_hwcap & HWCAP_VFP))
34 return 0;
35 }
36 return 1;
37}
38EXPORT_SYMBOL(elf_check_arch);
39
40void elf_set_personality(const struct elf32_hdr *x)
41{
42 unsigned int eflags = x->e_flags;
43 unsigned int personality = current->personality & ~PER_MASK;
44
45 /*
46 * We only support Linux ELF executables, so always set the
47 * personality to LINUX.
48 */
49 personality |= PER_LINUX;
50
51 /*
52 * APCS-26 is only valid for OABI executables
53 */
54 if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN &&
55 (eflags & EF_ARM_APCS_26))
56 personality &= ~ADDR_LIMIT_32BIT;
57 else
58 personality |= ADDR_LIMIT_32BIT;
59
60 set_personality(personality);
61
62 /*
63 * Since the FPA coprocessor uses CP1 and CP2, and iWMMXt uses CP0
64 * and CP1, we only enable access to the iWMMXt coprocessor if the
65 * binary is EABI or softfloat (and thus, guaranteed not to use
66 * FPA instructions.)
67 */
68 if (elf_hwcap & HWCAP_IWMMXT &&
69 eflags & (EF_ARM_EABI_MASK | EF_ARM_SOFT_FLOAT)) {
70 set_thread_flag(TIF_USING_IWMMXT);
71 } else {
72 clear_thread_flag(TIF_USING_IWMMXT);
73 }
74}
75EXPORT_SYMBOL(elf_set_personality);
76
77/*
78 * Set READ_IMPLIES_EXEC if:
79 * - the binary requires an executable stack
80 * - we're running on a CPU which doesn't support NX.
81 */
82int arm_elf_read_implies_exec(const struct elf32_hdr *x, int executable_stack)
83{
84 if (executable_stack != EXSTACK_DISABLE_X)
85 return 1;
86 if (cpu_architecture() < CPU_ARCH_ARMv6)
87 return 1;
88 return 0;
89}
90EXPORT_SYMBOL(arm_elf_read_implies_exec);