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#include <linux/module.h>
#include <linux/sched.h>
#include <linux/personality.h>
#include <linux/binfmts.h>
#include <linux/elf.h>
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 = PER_LINUX_32BIT;
/*
* APCS-26 is only valid for OABI executables
*/
if ((eflags & EF_ARM_EABI_MASK) == EF_ARM_EABI_UNKNOWN) {
if (eflags & EF_ARM_APCS_26)
personality = PER_LINUX;
}
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;
#if !defined(CONFIG_AEABI) || defined(CONFIG_OABI_COMPAT)
/*
* If we have support for OABI programs, we can never allow NX
* support - our signal syscall restart mechanism relies upon
* being able to execute code placed on the user stack.
*/
return 1;
#else
return 0;
#endif
}
EXPORT_SYMBOL(arm_elf_read_implies_exec);
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