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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _PKEYS_X86_H
#define _PKEYS_X86_H
#ifdef __i386__
#ifndef SYS_mprotect_key
# define SYS_mprotect_key 380
#endif
#ifndef SYS_pkey_alloc
# define SYS_pkey_alloc 381
# define SYS_pkey_free 382
#endif
#define REG_IP_IDX REG_EIP
#define si_pkey_offset 0x14
#else
#ifndef SYS_mprotect_key
# define SYS_mprotect_key 329
#endif
#ifndef SYS_pkey_alloc
# define SYS_pkey_alloc 330
# define SYS_pkey_free 331
#endif
#define REG_IP_IDX REG_RIP
#define si_pkey_offset 0x20
#endif
#ifndef PKEY_DISABLE_ACCESS
# define PKEY_DISABLE_ACCESS 0x1
#endif
#ifndef PKEY_DISABLE_WRITE
# define PKEY_DISABLE_WRITE 0x2
#endif
#define NR_PKEYS 16
#define PKEY_BITS_PER_PKEY 2
#define HPAGE_SIZE (1UL<<21)
#define PAGE_SIZE 4096
#define MB (1<<20)
static inline void __page_o_noops(void)
{
/* 8-bytes of instruction * 512 bytes = 1 page */
asm(".rept 512 ; nopl 0x7eeeeeee(%eax) ; .endr");
}
static inline unsigned int __read_pkey_reg(void)
{
unsigned int eax, edx;
unsigned int ecx = 0;
unsigned int pkey_reg;
asm volatile(".byte 0x0f,0x01,0xee\n\t"
: "=a" (eax), "=d" (edx)
: "c" (ecx));
pkey_reg = eax;
return pkey_reg;
}
static inline void __write_pkey_reg(unsigned int pkey_reg)
{
unsigned int eax = pkey_reg;
unsigned int ecx = 0;
unsigned int edx = 0;
dprintf4("%s() changing %08x to %08x\n", __func__,
__read_pkey_reg(), pkey_reg);
asm volatile(".byte 0x0f,0x01,0xef\n\t"
: : "a" (eax), "c" (ecx), "d" (edx));
assert(pkey_reg == __read_pkey_reg());
}
static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
unsigned int *ecx, unsigned int *edx)
{
/* ecx is often an input as well as an output. */
asm volatile(
"cpuid;"
: "=a" (*eax),
"=b" (*ebx),
"=c" (*ecx),
"=d" (*edx)
: "0" (*eax), "2" (*ecx));
}
/* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx) */
#define X86_FEATURE_PKU (1<<3) /* Protection Keys for Userspace */
#define X86_FEATURE_OSPKE (1<<4) /* OS Protection Keys Enable */
static inline int cpu_has_pku(void)
{
unsigned int eax;
unsigned int ebx;
unsigned int ecx;
unsigned int edx;
eax = 0x7;
ecx = 0x0;
__cpuid(&eax, &ebx, &ecx, &edx);
if (!(ecx & X86_FEATURE_PKU)) {
dprintf2("cpu does not have PKU\n");
return 0;
}
if (!(ecx & X86_FEATURE_OSPKE)) {
dprintf2("cpu does not have OSPKE\n");
return 0;
}
return 1;
}
#define XSTATE_PKEY_BIT (9)
#define XSTATE_PKEY 0x200
int pkey_reg_xstate_offset(void)
{
unsigned int eax;
unsigned int ebx;
unsigned int ecx;
unsigned int edx;
int xstate_offset;
int xstate_size;
unsigned long XSTATE_CPUID = 0xd;
int leaf;
/* assume that XSTATE_PKEY is set in XCR0 */
leaf = XSTATE_PKEY_BIT;
{
eax = XSTATE_CPUID;
ecx = leaf;
__cpuid(&eax, &ebx, &ecx, &edx);
if (leaf == XSTATE_PKEY_BIT) {
xstate_offset = ebx;
xstate_size = eax;
}
}
if (xstate_size == 0) {
printf("could not find size/offset of PKEY in xsave state\n");
return 0;
}
return xstate_offset;
}
#endif /* _PKEYS_X86_H */
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