| Russell King | 8ec5366 | 2008-09-07 17:16:54 +0100 | [diff] [blame^] | 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 | |
| 7 | int 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 | /* APCS26 is only allowed if the CPU supports it */ |
| 25 | if ((eflags & EF_ARM_APCS_26) && !(elf_hwcap & HWCAP_26BIT)) |
| 26 | return 0; |
| 27 | |
| 28 | /* VFP requires the supporting code */ |
| 29 | if ((eflags & EF_ARM_VFP_FLOAT) && !(elf_hwcap & HWCAP_VFP)) |
| 30 | return 0; |
| 31 | } |
| 32 | return 1; |
| 33 | } |
| 34 | EXPORT_SYMBOL(elf_check_arch); |
| 35 | |
| 36 | void elf_set_personality(const struct elf32_hdr *x) |
| 37 | { |
| 38 | unsigned int eflags = x->e_flags; |
| 39 | unsigned int personality = PER_LINUX_32BIT; |
| 40 | |
| 41 | /* |
| 42 | * APCS-26 is only valid for OABI executables |
| 43 | */ |
| 44 | if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN) { |
| 45 | if (eflags & EF_ARM_APCS_26) |
| 46 | personality = PER_LINUX; |
| 47 | } |
| 48 | |
| 49 | set_personality(personality); |
| 50 | |
| 51 | /* |
| 52 | * Since the FPA coprocessor uses CP1 and CP2, and iWMMXt uses CP0 |
| 53 | * and CP1, we only enable access to the iWMMXt coprocessor if the |
| 54 | * binary is EABI or softfloat (and thus, guaranteed not to use |
| 55 | * FPA instructions.) |
| 56 | */ |
| 57 | if (elf_hwcap & HWCAP_IWMMXT && |
| 58 | eflags & (EF_ARM_EABI_MASK | EF_ARM_SOFT_FLOAT)) { |
| 59 | set_thread_flag(TIF_USING_IWMMXT); |
| 60 | } else { |
| 61 | clear_thread_flag(TIF_USING_IWMMXT); |
| 62 | } |
| 63 | } |
| 64 | EXPORT_SYMBOL(elf_set_personality); |
| 65 | |
| 66 | /* |
| 67 | * Set READ_IMPLIES_EXEC if: |
| 68 | * - the binary requires an executable stack |
| 69 | * - we're running on a CPU which doesn't support NX. |
| 70 | */ |
| 71 | int arm_elf_read_implies_exec(const struct elf32_hdr *x, int executable_stack) |
| 72 | { |
| 73 | if (executable_stack != EXSTACK_ENABLE_X) |
| 74 | return 1; |
| 75 | if (cpu_architecture() <= CPU_ARCH_ARMv6) |
| 76 | return 1; |
| 77 | return 0; |
| 78 | } |
| 79 | EXPORT_SYMBOL(arm_elf_read_implies_exec); |