0c416bcaef
This introduces some functions that help with setting or clearing bits of a particular pkey. This also adds an abstraction for getting a pkey's bit position in the pkey register as this may vary across architectures. Signed-off-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Dave Hansen <dave.hansen@intel.com> Cc: "Desnes A. Nunes do Rosario" <desnesn@linux.vnet.ibm.com> Cc: Florian Weimer <fweimer@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ram Pai <linuxram@us.ibm.com> Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Suchanek <msuchanek@suse.de> Cc: Shuah Khan <shuah@kernel.org> Link: http://lkml.kernel.org/r/2ad9705f4f68ca7e72155cc583415e5a979546f1.1585646528.git.sandipan@linux.ibm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
162 lines
3.0 KiB
C
162 lines
3.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _PKEYS_X86_H
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#define _PKEYS_X86_H
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#ifdef __i386__
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#ifndef SYS_mprotect_key
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# define SYS_mprotect_key 380
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#endif
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#ifndef SYS_pkey_alloc
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# define SYS_pkey_alloc 381
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# define SYS_pkey_free 382
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#endif
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#define REG_IP_IDX REG_EIP
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#define si_pkey_offset 0x14
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#else
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#ifndef SYS_mprotect_key
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# define SYS_mprotect_key 329
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#endif
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#ifndef SYS_pkey_alloc
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# define SYS_pkey_alloc 330
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# define SYS_pkey_free 331
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#endif
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#define REG_IP_IDX REG_RIP
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#define si_pkey_offset 0x20
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#endif
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#ifndef PKEY_DISABLE_ACCESS
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# define PKEY_DISABLE_ACCESS 0x1
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#endif
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#ifndef PKEY_DISABLE_WRITE
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# define PKEY_DISABLE_WRITE 0x2
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#endif
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#define NR_PKEYS 16
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#define PKEY_BITS_PER_PKEY 2
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#define HPAGE_SIZE (1UL<<21)
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#define PAGE_SIZE 4096
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#define MB (1<<20)
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static inline void __page_o_noops(void)
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{
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/* 8-bytes of instruction * 512 bytes = 1 page */
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asm(".rept 512 ; nopl 0x7eeeeeee(%eax) ; .endr");
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}
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static inline u64 __read_pkey_reg(void)
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{
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unsigned int eax, edx;
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unsigned int ecx = 0;
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unsigned pkey_reg;
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asm volatile(".byte 0x0f,0x01,0xee\n\t"
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: "=a" (eax), "=d" (edx)
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: "c" (ecx));
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pkey_reg = eax;
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return pkey_reg;
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}
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static inline void __write_pkey_reg(u64 pkey_reg)
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{
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unsigned int eax = pkey_reg;
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unsigned int ecx = 0;
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unsigned int edx = 0;
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dprintf4("%s() changing %016llx to %016llx\n", __func__,
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__read_pkey_reg(), pkey_reg);
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asm volatile(".byte 0x0f,0x01,0xef\n\t"
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: : "a" (eax), "c" (ecx), "d" (edx));
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assert(pkey_reg == __read_pkey_reg());
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}
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static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
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unsigned int *ecx, unsigned int *edx)
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{
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/* ecx is often an input as well as an output. */
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asm volatile(
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"cpuid;"
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: "=a" (*eax),
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"=b" (*ebx),
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"=c" (*ecx),
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"=d" (*edx)
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: "0" (*eax), "2" (*ecx));
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}
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/* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx) */
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#define X86_FEATURE_PKU (1<<3) /* Protection Keys for Userspace */
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#define X86_FEATURE_OSPKE (1<<4) /* OS Protection Keys Enable */
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static inline int cpu_has_pku(void)
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{
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unsigned int eax;
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unsigned int ebx;
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unsigned int ecx;
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unsigned int edx;
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eax = 0x7;
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ecx = 0x0;
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__cpuid(&eax, &ebx, &ecx, &edx);
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if (!(ecx & X86_FEATURE_PKU)) {
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dprintf2("cpu does not have PKU\n");
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return 0;
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}
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if (!(ecx & X86_FEATURE_OSPKE)) {
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dprintf2("cpu does not have OSPKE\n");
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return 0;
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}
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return 1;
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}
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static inline u32 pkey_bit_position(int pkey)
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{
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return pkey * PKEY_BITS_PER_PKEY;
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}
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#define XSTATE_PKEY_BIT (9)
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#define XSTATE_PKEY 0x200
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int pkey_reg_xstate_offset(void)
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{
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unsigned int eax;
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unsigned int ebx;
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unsigned int ecx;
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unsigned int edx;
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int xstate_offset;
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int xstate_size;
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unsigned long XSTATE_CPUID = 0xd;
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int leaf;
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/* assume that XSTATE_PKEY is set in XCR0 */
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leaf = XSTATE_PKEY_BIT;
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{
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eax = XSTATE_CPUID;
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ecx = leaf;
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__cpuid(&eax, &ebx, &ecx, &edx);
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if (leaf == XSTATE_PKEY_BIT) {
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xstate_offset = ebx;
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xstate_size = eax;
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}
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}
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if (xstate_size == 0) {
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printf("could not find size/offset of PKEY in xsave state\n");
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return 0;
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}
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return xstate_offset;
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}
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#endif /* _PKEYS_X86_H */
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