| yuezonghe | 824eb0c | 2024-06-27 02:32:26 -0700 | [diff] [blame] | 1 | #include <linux/export.h> |
| 2 | #include <linux/sched.h> |
| 3 | #include <linux/personality.h> |
| 4 | #include <linux/binfmts.h> |
| 5 | #include <linux/elf.h> |
| 6 | #include <asm/system_info.h> |
| 7 | |
| 8 | int elf_check_arch(const struct elf32_hdr *x) |
| 9 | { |
| 10 | unsigned int eflags; |
| 11 | |
| 12 | /* Make sure it's an ARM executable */ |
| 13 | if (x->e_machine != EM_ARM) |
| 14 | return 0; |
| 15 | |
| 16 | /* Make sure the entry address is reasonable */ |
| 17 | if (x->e_entry & 1) { |
| 18 | if (!(elf_hwcap & HWCAP_THUMB)) |
| 19 | return 0; |
| 20 | } else if (x->e_entry & 3) |
| 21 | return 0; |
| 22 | |
| 23 | eflags = x->e_flags; |
| 24 | if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN) { |
| 25 | unsigned int flt_fmt; |
| 26 | |
| 27 | /* APCS26 is only allowed if the CPU supports it */ |
| 28 | if ((eflags & EF_ARM_APCS_26) && !(elf_hwcap & HWCAP_26BIT)) |
| 29 | return 0; |
| 30 | |
| 31 | flt_fmt = eflags & (EF_ARM_VFP_FLOAT | EF_ARM_SOFT_FLOAT); |
| 32 | |
| 33 | /* VFP requires the supporting code */ |
| 34 | if (flt_fmt == EF_ARM_VFP_FLOAT && !(elf_hwcap & HWCAP_VFP)) |
| 35 | return 0; |
| 36 | } |
| 37 | return 1; |
| 38 | } |
| 39 | EXPORT_SYMBOL(elf_check_arch); |
| 40 | |
| 41 | void elf_set_personality(const struct elf32_hdr *x) |
| 42 | { |
| 43 | unsigned int eflags = x->e_flags; |
| 44 | unsigned int personality = current->personality & ~PER_MASK; |
| 45 | |
| 46 | /* |
| 47 | * We only support Linux ELF executables, so always set the |
| 48 | * personality to LINUX. |
| 49 | */ |
| 50 | personality |= PER_LINUX; |
| 51 | |
| 52 | /* |
| 53 | * APCS-26 is only valid for OABI executables |
| 54 | */ |
| 55 | if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN && |
| 56 | (eflags & EF_ARM_APCS_26)) |
| 57 | personality &= ~ADDR_LIMIT_32BIT; |
| 58 | else |
| 59 | personality |= ADDR_LIMIT_32BIT; |
| 60 | |
| 61 | set_personality(personality); |
| 62 | |
| 63 | /* |
| 64 | * Since the FPA coprocessor uses CP1 and CP2, and iWMMXt uses CP0 |
| 65 | * and CP1, we only enable access to the iWMMXt coprocessor if the |
| 66 | * binary is EABI or softfloat (and thus, guaranteed not to use |
| 67 | * FPA instructions.) |
| 68 | */ |
| 69 | if (elf_hwcap & HWCAP_IWMMXT && |
| 70 | eflags & (EF_ARM_EABI_MASK | EF_ARM_SOFT_FLOAT)) { |
| 71 | set_thread_flag(TIF_USING_IWMMXT); |
| 72 | } else { |
| 73 | clear_thread_flag(TIF_USING_IWMMXT); |
| 74 | } |
| 75 | } |
| 76 | EXPORT_SYMBOL(elf_set_personality); |
| 77 | |
| 78 | /* |
| 79 | * Set READ_IMPLIES_EXEC if: |
| 80 | * - the binary requires an executable stack |
| 81 | * - we're running on a CPU which doesn't support NX. |
| 82 | */ |
| 83 | int arm_elf_read_implies_exec(const struct elf32_hdr *x, int executable_stack) |
| 84 | { |
| 85 | if (executable_stack != EXSTACK_DISABLE_X) |
| 86 | return 1; |
| 87 | if (cpu_architecture() < CPU_ARCH_ARMv6) |
| 88 | return 1; |
| 89 | return 0; |
| 90 | } |
| 91 | EXPORT_SYMBOL(arm_elf_read_implies_exec); |