From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- arch/arm/kernel/elf.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 arch/arm/kernel/elf.c (limited to 'arch/arm/kernel/elf.c') diff --git a/arch/arm/kernel/elf.c b/arch/arm/kernel/elf.c new file mode 100644 index 00000000..9b05c6a0 --- /dev/null +++ b/arch/arm/kernel/elf.c @@ -0,0 +1,90 @@ +#include +#include +#include +#include +#include + +int elf_check_arch(const struct elf32_hdr *x) +{ + unsigned int eflags; + + /* Make sure it's an ARM executable */ + if (x->e_machine != EM_ARM) + return 0; + + /* Make sure the entry address is reasonable */ + if (x->e_entry & 1) { + if (!(elf_hwcap & HWCAP_THUMB)) + return 0; + } else if (x->e_entry & 3) + return 0; + + eflags = x->e_flags; + if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN) { + unsigned int flt_fmt; + + /* APCS26 is only allowed if the CPU supports it */ + if ((eflags & EF_ARM_APCS_26) && !(elf_hwcap & HWCAP_26BIT)) + return 0; + + flt_fmt = eflags & (EF_ARM_VFP_FLOAT | EF_ARM_SOFT_FLOAT); + + /* VFP requires the supporting code */ + if (flt_fmt == EF_ARM_VFP_FLOAT && !(elf_hwcap & HWCAP_VFP)) + return 0; + } + return 1; +} +EXPORT_SYMBOL(elf_check_arch); + +void elf_set_personality(const struct elf32_hdr *x) +{ + unsigned int eflags = x->e_flags; + unsigned int personality = current->personality & ~PER_MASK; + + /* + * We only support Linux ELF executables, so always set the + * personality to LINUX. + */ + personality |= PER_LINUX; + + /* + * APCS-26 is only valid for OABI executables + */ + if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN && + (eflags & EF_ARM_APCS_26)) + personality &= ~ADDR_LIMIT_32BIT; + else + personality |= ADDR_LIMIT_32BIT; + + set_personality(personality); + + /* + * Since the FPA coprocessor uses CP1 and CP2, and iWMMXt uses CP0 + * and CP1, we only enable access to the iWMMXt coprocessor if the + * binary is EABI or softfloat (and thus, guaranteed not to use + * FPA instructions.) + */ + if (elf_hwcap & HWCAP_IWMMXT && + eflags & (EF_ARM_EABI_MASK | EF_ARM_SOFT_FLOAT)) { + set_thread_flag(TIF_USING_IWMMXT); + } else { + clear_thread_flag(TIF_USING_IWMMXT); + } +} +EXPORT_SYMBOL(elf_set_personality); + +/* + * Set READ_IMPLIES_EXEC if: + * - the binary requires an executable stack + * - we're running on a CPU which doesn't support NX. + */ +int arm_elf_read_implies_exec(const struct elf32_hdr *x, int executable_stack) +{ + if (executable_stack != EXSTACK_DISABLE_X) + return 1; + if (cpu_architecture() < CPU_ARCH_ARMv6) + return 1; + return 0; +} +EXPORT_SYMBOL(arm_elf_read_implies_exec); -- cgit v1.2.3