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>
7 #include <asm/system_info.h>
9 int elf_check_arch(const struct elf32_hdr *x)
13 /* Make sure it's an ARM executable */
14 if (x->e_machine != EM_ARM)
17 /* Make sure the entry address is reasonable */
19 if (!(elf_hwcap & HWCAP_THUMB))
21 } else if (x->e_entry & 3)
25 if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN) {
28 /* APCS26 is only allowed if the CPU supports it */
29 if ((eflags & EF_ARM_APCS_26) && !(elf_hwcap & HWCAP_26BIT))
32 flt_fmt = eflags & (EF_ARM_VFP_FLOAT | EF_ARM_SOFT_FLOAT);
34 /* VFP requires the supporting code */
35 if (flt_fmt == EF_ARM_VFP_FLOAT && !(elf_hwcap & HWCAP_VFP))
40 EXPORT_SYMBOL(elf_check_arch);
42 void elf_set_personality(const struct elf32_hdr *x)
44 unsigned int eflags = x->e_flags;
45 unsigned int personality = current->personality & ~PER_MASK;
48 * We only support Linux ELF executables, so always set the
49 * personality to LINUX.
51 personality |= PER_LINUX;
54 * APCS-26 is only valid for OABI executables
56 if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN &&
57 (eflags & EF_ARM_APCS_26))
58 personality &= ~ADDR_LIMIT_32BIT;
60 personality |= ADDR_LIMIT_32BIT;
62 set_personality(personality);
65 * Since the FPA coprocessor uses CP1 and CP2, and iWMMXt uses CP0
66 * and CP1, we only enable access to the iWMMXt coprocessor if the
67 * binary is EABI or softfloat (and thus, guaranteed not to use
70 if (elf_hwcap & HWCAP_IWMMXT &&
71 eflags & (EF_ARM_EABI_MASK | EF_ARM_SOFT_FLOAT)) {
72 set_thread_flag(TIF_USING_IWMMXT);
74 clear_thread_flag(TIF_USING_IWMMXT);
77 EXPORT_SYMBOL(elf_set_personality);
80 * Set READ_IMPLIES_EXEC if:
81 * - the binary requires an executable stack
82 * - we're running on a CPU which doesn't support NX.
84 int arm_elf_read_implies_exec(const struct elf32_hdr *x, int executable_stack)
86 if (executable_stack != EXSTACK_DISABLE_X)
88 if (cpu_architecture() < CPU_ARCH_ARMv6)
92 EXPORT_SYMBOL(arm_elf_read_implies_exec);