tools/testing/selftests/sgx/main.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/sgx/main.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/sgx/main.c
Extension
.c
Size
56092 bytes
Lines
1994
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

struct vdso_symtab {
	Elf64_Sym *elf_symtab;
	const char *elf_symstrtab;
	Elf64_Word *elf_hashtab;
};

static Elf64_Dyn *vdso_get_dyntab(void *addr)
{
	Elf64_Ehdr *ehdr = addr;
	Elf64_Phdr *phdrtab = addr + ehdr->e_phoff;
	int i;

	for (i = 0; i < ehdr->e_phnum; i++)
		if (phdrtab[i].p_type == PT_DYNAMIC)
			return addr + phdrtab[i].p_offset;

	return NULL;
}

static void *vdso_get_dyn(void *addr, Elf64_Dyn *dyntab, Elf64_Sxword tag)
{
	int i;

	for (i = 0; dyntab[i].d_tag != DT_NULL; i++)
		if (dyntab[i].d_tag == tag)
			return addr + dyntab[i].d_un.d_ptr;

	return NULL;
}

static bool vdso_get_symtab(void *addr, struct vdso_symtab *symtab)
{
	Elf64_Dyn *dyntab = vdso_get_dyntab(addr);

	symtab->elf_symtab = vdso_get_dyn(addr, dyntab, DT_SYMTAB);
	if (!symtab->elf_symtab)
		return false;

	symtab->elf_symstrtab = vdso_get_dyn(addr, dyntab, DT_STRTAB);
	if (!symtab->elf_symstrtab)
		return false;

	symtab->elf_hashtab = vdso_get_dyn(addr, dyntab, DT_HASH);
	if (!symtab->elf_hashtab)
		return false;

	return true;
}

static inline int sgx2_supported(void)
{
	unsigned int eax, ebx, ecx, edx;

	__cpuid_count(SGX_CPUID, 0x0, eax, ebx, ecx, edx);

	return eax & 0x2;
}

static unsigned long elf_sym_hash(const char *name)
{
	unsigned long h = 0, high;

	while (*name) {
		h = (h << 4) + *name++;
		high = h & 0xf0000000;

		if (high)
			h ^= high >> 24;

		h &= ~high;
	}

	return h;
}

static Elf64_Sym *vdso_symtab_get(struct vdso_symtab *symtab, const char *name)
{
	Elf64_Word bucketnum = symtab->elf_hashtab[0];
	Elf64_Word *buckettab = &symtab->elf_hashtab[2];
	Elf64_Word *chaintab = &symtab->elf_hashtab[2 + bucketnum];
	Elf64_Sym *sym;
	Elf64_Word i;

	for (i = buckettab[elf_sym_hash(name) % bucketnum]; i != STN_UNDEF;
	     i = chaintab[i]) {
		sym = &symtab->elf_symtab[i];
		if (!strcmp(name, &symtab->elf_symstrtab[sym->st_name]))
			return sym;
	}

Annotation

Implementation Notes