Merge remote-tracking branch 'spi/fix/s3c64xx' into spi-linus
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / kernel / elf.c
CommitLineData
ecea4ab6 1#include <linux/export.h>
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2#include <linux/sched.h>
3#include <linux/personality.h>
4#include <linux/binfmts.h>
5#include <linux/elf.h>
9f97da78 6#include <asm/system_info.h>
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7
8int 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) {
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25 unsigned int flt_fmt;
26
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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
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31 flt_fmt = eflags & (EF_ARM_VFP_FLOAT | EF_ARM_SOFT_FLOAT);
32
8ec53663 33 /* VFP requires the supporting code */
d2ed5cb8 34 if (flt_fmt == EF_ARM_VFP_FLOAT && !(elf_hwcap & HWCAP_VFP))
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35 return 0;
36 }
37 return 1;
38}
39EXPORT_SYMBOL(elf_check_arch);
40
41void elf_set_personality(const struct elf32_hdr *x)
42{
43 unsigned int eflags = x->e_flags;
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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;
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51
52 /*
53 * APCS-26 is only valid for OABI executables
54 */
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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;
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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}
76EXPORT_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 */
83int arm_elf_read_implies_exec(const struct elf32_hdr *x, int executable_stack)
84{
9da616fb 85 if (executable_stack != EXSTACK_DISABLE_X)
8ec53663 86 return 1;
9da616fb 87 if (cpu_architecture() < CPU_ARCH_ARMv6)
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88 return 1;
89 return 0;
90}
91EXPORT_SYMBOL(arm_elf_read_implies_exec);