1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 262784854SIngo Molnar /* 362784854SIngo Molnar * xsave/xrstor support. 462784854SIngo Molnar * 562784854SIngo Molnar * Author: Suresh Siddha <suresh.b.siddha@intel.com> 662784854SIngo Molnar */ 762784854SIngo Molnar #include <linux/compat.h> 862784854SIngo Molnar #include <linux/cpu.h> 9e8c24d3aSDave Hansen #include <linux/mman.h> 1084594296SDave Hansen #include <linux/pkeys.h> 110c608dadSAubrey Li #include <linux/seq_file.h> 120c608dadSAubrey Li #include <linux/proc_fs.h> 1359a36d16SIngo Molnar 1462784854SIngo Molnar #include <asm/fpu/api.h> 1562784854SIngo Molnar #include <asm/fpu/internal.h> 16fcbc99c4SIngo Molnar #include <asm/fpu/signal.h> 1759a36d16SIngo Molnar #include <asm/fpu/regset.h> 1891c3dba7SYu-cheng Yu #include <asm/fpu/xstate.h> 19b992c660SIngo Molnar 2062784854SIngo Molnar #include <asm/tlbflush.h> 21ccb18db2SAndi Kleen #include <asm/cpufeature.h> 2262784854SIngo Molnar 231f96b1efSDave Hansen /* 241f96b1efSDave Hansen * Although we spell it out in here, the Processor Trace 251f96b1efSDave Hansen * xfeature is completely unused. We use other mechanisms 261f96b1efSDave Hansen * to save/restore PT state in Linux. 271f96b1efSDave Hansen */ 285b073430SIngo Molnar static const char *xfeature_names[] = 295b073430SIngo Molnar { 305b073430SIngo Molnar "x87 floating point registers" , 315b073430SIngo Molnar "SSE registers" , 325b073430SIngo Molnar "AVX registers" , 335b073430SIngo Molnar "MPX bounds registers" , 345b073430SIngo Molnar "MPX CSR" , 355b073430SIngo Molnar "AVX-512 opmask" , 365b073430SIngo Molnar "AVX-512 Hi256" , 375b073430SIngo Molnar "AVX-512 ZMM_Hi256" , 381f96b1efSDave Hansen "Processor Trace (unused)" , 39c8df4009SDave Hansen "Protection Keys User registers", 405b073430SIngo Molnar "unknown xstate feature" , 415b073430SIngo Molnar }; 425b073430SIngo Molnar 43ccb18db2SAndi Kleen static short xsave_cpuid_features[] __initdata = { 44ccb18db2SAndi Kleen X86_FEATURE_FPU, 45ccb18db2SAndi Kleen X86_FEATURE_XMM, 46ccb18db2SAndi Kleen X86_FEATURE_AVX, 47ccb18db2SAndi Kleen X86_FEATURE_MPX, 48ccb18db2SAndi Kleen X86_FEATURE_MPX, 49ccb18db2SAndi Kleen X86_FEATURE_AVX512F, 50ccb18db2SAndi Kleen X86_FEATURE_AVX512F, 51ccb18db2SAndi Kleen X86_FEATURE_AVX512F, 52ccb18db2SAndi Kleen X86_FEATURE_INTEL_PT, 53ccb18db2SAndi Kleen X86_FEATURE_PKU, 54ccb18db2SAndi Kleen }; 55ccb18db2SAndi Kleen 5662784854SIngo Molnar /* 5762784854SIngo Molnar * Mask of xstate features supported by the CPU and the kernel: 5862784854SIngo Molnar */ 595b073430SIngo Molnar u64 xfeatures_mask __read_mostly; 6062784854SIngo Molnar 61dad8c4feSDave Hansen static unsigned int xstate_offsets[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1}; 62dad8c4feSDave Hansen static unsigned int xstate_sizes[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1}; 63c0855051SCyrill Gorcunov static unsigned int xstate_comp_offsets[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1}; 6462784854SIngo Molnar 6562784854SIngo Molnar /* 66a1141e0bSFenghua Yu * The XSAVE area of kernel can be in standard or compacted format; 67a1141e0bSFenghua Yu * it is always in standard format for user mode. This is the user 68a1141e0bSFenghua Yu * mode standard format size used for signal and ptrace frames. 69a1141e0bSFenghua Yu */ 70a1141e0bSFenghua Yu unsigned int fpu_user_xstate_size; 71a1141e0bSFenghua Yu 72a1141e0bSFenghua Yu /* 735b073430SIngo Molnar * Return whether the system supports a given xfeature. 745b073430SIngo Molnar * 755b073430SIngo Molnar * Also return the name of the (most advanced) feature that the caller requested: 765b073430SIngo Molnar */ 775b073430SIngo Molnar int cpu_has_xfeatures(u64 xfeatures_needed, const char **feature_name) 785b073430SIngo Molnar { 795b073430SIngo Molnar u64 xfeatures_missing = xfeatures_needed & ~xfeatures_mask; 805b073430SIngo Molnar 815b073430SIngo Molnar if (unlikely(feature_name)) { 825b073430SIngo Molnar long xfeature_idx, max_idx; 835b073430SIngo Molnar u64 xfeatures_print; 845b073430SIngo Molnar /* 855b073430SIngo Molnar * So we use FLS here to be able to print the most advanced 865b073430SIngo Molnar * feature that was requested but is missing. So if a driver 87d91cab78SDave Hansen * asks about "XFEATURE_MASK_SSE | XFEATURE_MASK_YMM" we'll print the 885b073430SIngo Molnar * missing AVX feature - this is the most informative message 895b073430SIngo Molnar * to users: 905b073430SIngo Molnar */ 915b073430SIngo Molnar if (xfeatures_missing) 925b073430SIngo Molnar xfeatures_print = xfeatures_missing; 935b073430SIngo Molnar else 945b073430SIngo Molnar xfeatures_print = xfeatures_needed; 955b073430SIngo Molnar 965b073430SIngo Molnar xfeature_idx = fls64(xfeatures_print)-1; 975b073430SIngo Molnar max_idx = ARRAY_SIZE(xfeature_names)-1; 985b073430SIngo Molnar xfeature_idx = min(xfeature_idx, max_idx); 995b073430SIngo Molnar 1005b073430SIngo Molnar *feature_name = xfeature_names[xfeature_idx]; 1015b073430SIngo Molnar } 1025b073430SIngo Molnar 1035b073430SIngo Molnar if (xfeatures_missing) 1045b073430SIngo Molnar return 0; 1055b073430SIngo Molnar 1065b073430SIngo Molnar return 1; 1075b073430SIngo Molnar } 1085b073430SIngo Molnar EXPORT_SYMBOL_GPL(cpu_has_xfeatures); 1095b073430SIngo Molnar 110158e2ee6SYu-cheng Yu static bool xfeature_is_supervisor(int xfeature_nr) 1111499ce2dSYu-cheng Yu { 1121499ce2dSYu-cheng Yu /* 1138c9e6073SYu-cheng Yu * Extended State Enumeration Sub-leaves (EAX = 0DH, ECX = n, n > 1) 1148c9e6073SYu-cheng Yu * returns ECX[0] set to (1) for a supervisor state, and cleared (0) 1158c9e6073SYu-cheng Yu * for a user state. 1161499ce2dSYu-cheng Yu */ 1171499ce2dSYu-cheng Yu u32 eax, ebx, ecx, edx; 1181499ce2dSYu-cheng Yu 1191499ce2dSYu-cheng Yu cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); 120158e2ee6SYu-cheng Yu return ecx & 1; 1211499ce2dSYu-cheng Yu } 1221499ce2dSYu-cheng Yu 1235b073430SIngo Molnar /* 124aeb997b9SIngo Molnar * When executing XSAVEOPT (or other optimized XSAVE instructions), if 125aeb997b9SIngo Molnar * a processor implementation detects that an FPU state component is still 126aeb997b9SIngo Molnar * (or is again) in its initialized state, it may clear the corresponding 127aeb997b9SIngo Molnar * bit in the header.xfeatures field, and can skip the writeout of registers 128aeb997b9SIngo Molnar * to the corresponding memory layout. 12962784854SIngo Molnar * 13062784854SIngo Molnar * This means that when the bit is zero, the state component might still contain 13162784854SIngo Molnar * some previous - non-initialized register state. 13262784854SIngo Molnar * 13362784854SIngo Molnar * Before writing xstate information to user-space we sanitize those components, 13462784854SIngo Molnar * to always ensure that the memory layout of a feature will be in the init state 13562784854SIngo Molnar * if the corresponding header bit is zero. This is to ensure that user-space doesn't 13662784854SIngo Molnar * see some stale state in the memory layout during signal handling, debugging etc. 13762784854SIngo Molnar */ 13836e49e7fSIngo Molnar void fpstate_sanitize_xstate(struct fpu *fpu) 13962784854SIngo Molnar { 140c47ada30SIngo Molnar struct fxregs_state *fx = &fpu->state.fxsave; 14162784854SIngo Molnar int feature_bit; 14262784854SIngo Molnar u64 xfeatures; 14362784854SIngo Molnar 1441ac91a76SIngo Molnar if (!use_xsaveopt()) 14562784854SIngo Molnar return; 14662784854SIngo Molnar 14736e49e7fSIngo Molnar xfeatures = fpu->state.xsave.header.xfeatures; 14862784854SIngo Molnar 14962784854SIngo Molnar /* 15062784854SIngo Molnar * None of the feature bits are in init state. So nothing else 15162784854SIngo Molnar * to do for us, as the memory layout is up to date. 15262784854SIngo Molnar */ 15362784854SIngo Molnar if ((xfeatures & xfeatures_mask) == xfeatures_mask) 15462784854SIngo Molnar return; 15562784854SIngo Molnar 15662784854SIngo Molnar /* 15762784854SIngo Molnar * FP is in init state 15862784854SIngo Molnar */ 159d91cab78SDave Hansen if (!(xfeatures & XFEATURE_MASK_FP)) { 16062784854SIngo Molnar fx->cwd = 0x37f; 16162784854SIngo Molnar fx->swd = 0; 16262784854SIngo Molnar fx->twd = 0; 16362784854SIngo Molnar fx->fop = 0; 16462784854SIngo Molnar fx->rip = 0; 16562784854SIngo Molnar fx->rdp = 0; 16662784854SIngo Molnar memset(&fx->st_space[0], 0, 128); 16762784854SIngo Molnar } 16862784854SIngo Molnar 16962784854SIngo Molnar /* 17062784854SIngo Molnar * SSE is in init state 17162784854SIngo Molnar */ 172d91cab78SDave Hansen if (!(xfeatures & XFEATURE_MASK_SSE)) 17362784854SIngo Molnar memset(&fx->xmm_space[0], 0, 256); 17462784854SIngo Molnar 17562784854SIngo Molnar /* 17662784854SIngo Molnar * First two features are FPU and SSE, which above we handled 17762784854SIngo Molnar * in a special way already: 17862784854SIngo Molnar */ 17962784854SIngo Molnar feature_bit = 0x2; 18062784854SIngo Molnar xfeatures = (xfeatures_mask & ~xfeatures) >> 2; 18162784854SIngo Molnar 18262784854SIngo Molnar /* 18362784854SIngo Molnar * Update all the remaining memory layouts according to their 18462784854SIngo Molnar * standard xstate layout, if their header bit is in the init 18562784854SIngo Molnar * state: 18662784854SIngo Molnar */ 18762784854SIngo Molnar while (xfeatures) { 18862784854SIngo Molnar if (xfeatures & 0x1) { 189a1141e0bSFenghua Yu int offset = xstate_comp_offsets[feature_bit]; 19062784854SIngo Molnar int size = xstate_sizes[feature_bit]; 19162784854SIngo Molnar 19262784854SIngo Molnar memcpy((void *)fx + offset, 1936f575023SIngo Molnar (void *)&init_fpstate.xsave + offset, 19462784854SIngo Molnar size); 19562784854SIngo Molnar } 19662784854SIngo Molnar 19762784854SIngo Molnar xfeatures >>= 1; 19862784854SIngo Molnar feature_bit++; 19962784854SIngo Molnar } 20062784854SIngo Molnar } 20162784854SIngo Molnar 20262784854SIngo Molnar /* 20362784854SIngo Molnar * Enable the extended processor state save/restore feature. 20462784854SIngo Molnar * Called once per CPU onlining. 20562784854SIngo Molnar */ 20662784854SIngo Molnar void fpu__init_cpu_xstate(void) 20762784854SIngo Molnar { 208d366bf7eSBorislav Petkov if (!boot_cpu_has(X86_FEATURE_XSAVE) || !xfeatures_mask) 20962784854SIngo Molnar return; 210b8be15d5SYu-cheng Yu /* 211b8be15d5SYu-cheng Yu * Make it clear that XSAVES supervisor states are not yet 212b8be15d5SYu-cheng Yu * implemented should anyone expect it to work by changing 213b8be15d5SYu-cheng Yu * bits in XFEATURE_MASK_* macros and XCR0. 214b8be15d5SYu-cheng Yu */ 215b8be15d5SYu-cheng Yu WARN_ONCE((xfeatures_mask & XFEATURE_MASK_SUPERVISOR), 216b8be15d5SYu-cheng Yu "x86/fpu: XSAVES supervisor states are not yet implemented.\n"); 217b8be15d5SYu-cheng Yu 218b8be15d5SYu-cheng Yu xfeatures_mask &= ~XFEATURE_MASK_SUPERVISOR; 21962784854SIngo Molnar 22062784854SIngo Molnar cr4_set_bits(X86_CR4_OSXSAVE); 22162784854SIngo Molnar xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask); 22262784854SIngo Molnar } 22362784854SIngo Molnar 22462784854SIngo Molnar /* 225e6e888f9SDave Hansen * Note that in the future we will likely need a pair of 226e6e888f9SDave Hansen * functions here: one for user xstates and the other for 227e6e888f9SDave Hansen * system xstates. For now, they are the same. 228e6e888f9SDave Hansen */ 229e6e888f9SDave Hansen static int xfeature_enabled(enum xfeature xfeature) 230e6e888f9SDave Hansen { 231e6e888f9SDave Hansen return !!(xfeatures_mask & (1UL << xfeature)); 232e6e888f9SDave Hansen } 233e6e888f9SDave Hansen 234e6e888f9SDave Hansen /* 23539f1acd2SIngo Molnar * Record the offsets and sizes of various xstates contained 23639f1acd2SIngo Molnar * in the XSAVE state memory layout. 23762784854SIngo Molnar */ 23862784854SIngo Molnar static void __init setup_xstate_features(void) 23962784854SIngo Molnar { 240ee9ae257SDave Hansen u32 eax, ebx, ecx, edx, i; 241e6e888f9SDave Hansen /* start at the beginnning of the "extended state" */ 242e6e888f9SDave Hansen unsigned int last_good_offset = offsetof(struct xregs_state, 243e6e888f9SDave Hansen extended_state_area); 244ac73b27aSYu-cheng Yu /* 245ac73b27aSYu-cheng Yu * The FP xstates and SSE xstates are legacy states. They are always 246ac73b27aSYu-cheng Yu * in the fixed offsets in the xsave area in either compacted form 247ac73b27aSYu-cheng Yu * or standard form. 248ac73b27aSYu-cheng Yu */ 249446e693cSCyrill Gorcunov xstate_offsets[XFEATURE_FP] = 0; 250446e693cSCyrill Gorcunov xstate_sizes[XFEATURE_FP] = offsetof(struct fxregs_state, 251446e693cSCyrill Gorcunov xmm_space); 252446e693cSCyrill Gorcunov 253446e693cSCyrill Gorcunov xstate_offsets[XFEATURE_SSE] = xstate_sizes[XFEATURE_FP]; 254c593642cSPankaj Bharadiya xstate_sizes[XFEATURE_SSE] = sizeof_field(struct fxregs_state, 255446e693cSCyrill Gorcunov xmm_space); 25662784854SIngo Molnar 257ee9ae257SDave Hansen for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { 258e6e888f9SDave Hansen if (!xfeature_enabled(i)) 259e6e888f9SDave Hansen continue; 26062784854SIngo Molnar 261e6e888f9SDave Hansen cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx); 2621499ce2dSYu-cheng Yu 263c12e13dcSYu-cheng Yu xstate_sizes[i] = eax; 264c12e13dcSYu-cheng Yu 2651499ce2dSYu-cheng Yu /* 266c12e13dcSYu-cheng Yu * If an xfeature is supervisor state, the offset in EBX is 267c12e13dcSYu-cheng Yu * invalid, leave it to -1. 2681499ce2dSYu-cheng Yu */ 269c12e13dcSYu-cheng Yu if (xfeature_is_supervisor(i)) 270c12e13dcSYu-cheng Yu continue; 271c12e13dcSYu-cheng Yu 272ee9ae257SDave Hansen xstate_offsets[i] = ebx; 2731499ce2dSYu-cheng Yu 274e6e888f9SDave Hansen /* 275c12e13dcSYu-cheng Yu * In our xstate size checks, we assume that the highest-numbered 276c12e13dcSYu-cheng Yu * xstate feature has the highest offset in the buffer. Ensure 277c12e13dcSYu-cheng Yu * it does. 278e6e888f9SDave Hansen */ 279e6e888f9SDave Hansen WARN_ONCE(last_good_offset > xstate_offsets[i], 280e6e888f9SDave Hansen "x86/fpu: misordered xstate at %d\n", last_good_offset); 281c12e13dcSYu-cheng Yu 282e6e888f9SDave Hansen last_good_offset = xstate_offsets[i]; 28339f1acd2SIngo Molnar } 28462784854SIngo Molnar } 28562784854SIngo Molnar 28632231879SIngo Molnar static void __init print_xstate_feature(u64 xstate_mask) 28762784854SIngo Molnar { 28833588b52SIngo Molnar const char *feature_name; 28962784854SIngo Molnar 29033588b52SIngo Molnar if (cpu_has_xfeatures(xstate_mask, &feature_name)) 291c8df4009SDave Hansen pr_info("x86/fpu: Supporting XSAVE feature 0x%03Lx: '%s'\n", xstate_mask, feature_name); 29262784854SIngo Molnar } 29362784854SIngo Molnar 29462784854SIngo Molnar /* 29562784854SIngo Molnar * Print out all the supported xstate features: 29662784854SIngo Molnar */ 29732231879SIngo Molnar static void __init print_xstate_features(void) 29862784854SIngo Molnar { 299d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_FP); 300d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_SSE); 301d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_YMM); 302d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_BNDREGS); 303d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_BNDCSR); 304d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_OPMASK); 305d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_ZMM_Hi256); 306d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_Hi16_ZMM); 307c8df4009SDave Hansen print_xstate_feature(XFEATURE_MASK_PKRU); 30862784854SIngo Molnar } 30962784854SIngo Molnar 31062784854SIngo Molnar /* 31103482e08SYu-cheng Yu * This check is important because it is easy to get XSTATE_* 31203482e08SYu-cheng Yu * confused with XSTATE_BIT_*. 31303482e08SYu-cheng Yu */ 31403482e08SYu-cheng Yu #define CHECK_XFEATURE(nr) do { \ 31503482e08SYu-cheng Yu WARN_ON(nr < FIRST_EXTENDED_XFEATURE); \ 31603482e08SYu-cheng Yu WARN_ON(nr >= XFEATURE_MAX); \ 31703482e08SYu-cheng Yu } while (0) 31803482e08SYu-cheng Yu 31903482e08SYu-cheng Yu /* 32003482e08SYu-cheng Yu * We could cache this like xstate_size[], but we only use 32103482e08SYu-cheng Yu * it here, so it would be a waste of space. 32203482e08SYu-cheng Yu */ 32303482e08SYu-cheng Yu static int xfeature_is_aligned(int xfeature_nr) 32403482e08SYu-cheng Yu { 32503482e08SYu-cheng Yu u32 eax, ebx, ecx, edx; 32603482e08SYu-cheng Yu 32703482e08SYu-cheng Yu CHECK_XFEATURE(xfeature_nr); 328e70b1008SYu-cheng Yu 329e70b1008SYu-cheng Yu if (!xfeature_enabled(xfeature_nr)) { 330e70b1008SYu-cheng Yu WARN_ONCE(1, "Checking alignment of disabled xfeature %d\n", 331e70b1008SYu-cheng Yu xfeature_nr); 332e70b1008SYu-cheng Yu return 0; 333e70b1008SYu-cheng Yu } 334e70b1008SYu-cheng Yu 33503482e08SYu-cheng Yu cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); 33603482e08SYu-cheng Yu /* 33703482e08SYu-cheng Yu * The value returned by ECX[1] indicates the alignment 33803482e08SYu-cheng Yu * of state component 'i' when the compacted format 33903482e08SYu-cheng Yu * of the extended region of an XSAVE area is used: 34003482e08SYu-cheng Yu */ 34103482e08SYu-cheng Yu return !!(ecx & 2); 34203482e08SYu-cheng Yu } 34303482e08SYu-cheng Yu 34403482e08SYu-cheng Yu /* 34562784854SIngo Molnar * This function sets up offsets and sizes of all extended states in 34662784854SIngo Molnar * xsave area. This supports both standard format and compacted format 34749a91d61SYu-cheng Yu * of the xsave area. 34862784854SIngo Molnar */ 34949a91d61SYu-cheng Yu static void __init setup_xstate_comp_offsets(void) 35062784854SIngo Molnar { 35149a91d61SYu-cheng Yu unsigned int next_offset; 35262784854SIngo Molnar int i; 35362784854SIngo Molnar 35462784854SIngo Molnar /* 35562784854SIngo Molnar * The FP xstates and SSE xstates are legacy states. They are always 35662784854SIngo Molnar * in the fixed offsets in the xsave area in either compacted form 35762784854SIngo Molnar * or standard form. 35862784854SIngo Molnar */ 359446e693cSCyrill Gorcunov xstate_comp_offsets[XFEATURE_FP] = 0; 360446e693cSCyrill Gorcunov xstate_comp_offsets[XFEATURE_SSE] = offsetof(struct fxregs_state, 361446e693cSCyrill Gorcunov xmm_space); 36262784854SIngo Molnar 363782511b0SBorislav Petkov if (!boot_cpu_has(X86_FEATURE_XSAVES)) { 364ee9ae257SDave Hansen for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { 36549a91d61SYu-cheng Yu if (xfeature_enabled(i)) 36662784854SIngo Molnar xstate_comp_offsets[i] = xstate_offsets[i]; 36762784854SIngo Molnar } 36862784854SIngo Molnar return; 36962784854SIngo Molnar } 37062784854SIngo Molnar 37149a91d61SYu-cheng Yu next_offset = FXSAVE_SIZE + XSAVE_HDR_SIZE; 37262784854SIngo Molnar 373ee9ae257SDave Hansen for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { 37449a91d61SYu-cheng Yu if (!xfeature_enabled(i)) 37549a91d61SYu-cheng Yu continue; 37662784854SIngo Molnar 37703482e08SYu-cheng Yu if (xfeature_is_aligned(i)) 37849a91d61SYu-cheng Yu next_offset = ALIGN(next_offset, 64); 37949a91d61SYu-cheng Yu 38049a91d61SYu-cheng Yu xstate_comp_offsets[i] = next_offset; 38149a91d61SYu-cheng Yu next_offset += xstate_sizes[i]; 38262784854SIngo Molnar } 38362784854SIngo Molnar } 38462784854SIngo Molnar 38562784854SIngo Molnar /* 386996952e0SYu-cheng Yu * Print out xstate component offsets and sizes 387996952e0SYu-cheng Yu */ 388996952e0SYu-cheng Yu static void __init print_xstate_offset_size(void) 389996952e0SYu-cheng Yu { 390996952e0SYu-cheng Yu int i; 391996952e0SYu-cheng Yu 392996952e0SYu-cheng Yu for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { 393996952e0SYu-cheng Yu if (!xfeature_enabled(i)) 394996952e0SYu-cheng Yu continue; 395996952e0SYu-cheng Yu pr_info("x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n", 396996952e0SYu-cheng Yu i, xstate_comp_offsets[i], i, xstate_sizes[i]); 397996952e0SYu-cheng Yu } 398996952e0SYu-cheng Yu } 399996952e0SYu-cheng Yu 400996952e0SYu-cheng Yu /* 40162784854SIngo Molnar * setup the xstate image representing the init state 40262784854SIngo Molnar */ 40332231879SIngo Molnar static void __init setup_init_fpu_buf(void) 40462784854SIngo Molnar { 405e49a449bSRasmus Villemoes static int on_boot_cpu __initdata = 1; 406e97131a8SIngo Molnar 407e97131a8SIngo Molnar WARN_ON_FPU(!on_boot_cpu); 408e97131a8SIngo Molnar on_boot_cpu = 0; 409e97131a8SIngo Molnar 410d366bf7eSBorislav Petkov if (!boot_cpu_has(X86_FEATURE_XSAVE)) 41162784854SIngo Molnar return; 41262784854SIngo Molnar 41362784854SIngo Molnar setup_xstate_features(); 41462784854SIngo Molnar print_xstate_features(); 41562784854SIngo Molnar 4167d937060SFenghua Yu if (boot_cpu_has(X86_FEATURE_XSAVES)) 4178c9e6073SYu-cheng Yu init_fpstate.xsave.header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT | 4188c9e6073SYu-cheng Yu xfeatures_mask; 41962784854SIngo Molnar 42062784854SIngo Molnar /* 4217d937060SFenghua Yu * Init all the features state with header.xfeatures being 0x0 42262784854SIngo Molnar */ 423d65fcd60SIngo Molnar copy_kernel_to_xregs_booting(&init_fpstate.xsave); 42462784854SIngo Molnar 42562784854SIngo Molnar /* 42662784854SIngo Molnar * Dump the init state again. This is to identify the init state 42762784854SIngo Molnar * of any feature which is not represented by all zero's. 42862784854SIngo Molnar */ 429c6813144SIngo Molnar copy_xregs_to_kernel_booting(&init_fpstate.xsave); 43062784854SIngo Molnar } 43162784854SIngo Molnar 43265ac2e9bSDave Hansen static int xfeature_uncompacted_offset(int xfeature_nr) 43365ac2e9bSDave Hansen { 43465ac2e9bSDave Hansen u32 eax, ebx, ecx, edx; 43565ac2e9bSDave Hansen 4361499ce2dSYu-cheng Yu /* 4371499ce2dSYu-cheng Yu * Only XSAVES supports supervisor states and it uses compacted 4381499ce2dSYu-cheng Yu * format. Checking a supervisor state's uncompacted offset is 4391499ce2dSYu-cheng Yu * an error. 4401499ce2dSYu-cheng Yu */ 441d0845239SSebastian Andrzej Siewior if (XFEATURE_MASK_SUPERVISOR & BIT_ULL(xfeature_nr)) { 4421499ce2dSYu-cheng Yu WARN_ONCE(1, "No fixed offset for xstate %d\n", xfeature_nr); 4431499ce2dSYu-cheng Yu return -1; 4441499ce2dSYu-cheng Yu } 4451499ce2dSYu-cheng Yu 44665ac2e9bSDave Hansen CHECK_XFEATURE(xfeature_nr); 44765ac2e9bSDave Hansen cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); 44865ac2e9bSDave Hansen return ebx; 44965ac2e9bSDave Hansen } 45065ac2e9bSDave Hansen 45165ac2e9bSDave Hansen static int xfeature_size(int xfeature_nr) 45265ac2e9bSDave Hansen { 45365ac2e9bSDave Hansen u32 eax, ebx, ecx, edx; 45465ac2e9bSDave Hansen 45565ac2e9bSDave Hansen CHECK_XFEATURE(xfeature_nr); 45665ac2e9bSDave Hansen cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); 45765ac2e9bSDave Hansen return eax; 45865ac2e9bSDave Hansen } 45965ac2e9bSDave Hansen 46065ac2e9bSDave Hansen /* 46165ac2e9bSDave Hansen * 'XSAVES' implies two different things: 46265ac2e9bSDave Hansen * 1. saving of supervisor/system state 46365ac2e9bSDave Hansen * 2. using the compacted format 46465ac2e9bSDave Hansen * 46565ac2e9bSDave Hansen * Use this function when dealing with the compacted format so 46665ac2e9bSDave Hansen * that it is obvious which aspect of 'XSAVES' is being handled 46765ac2e9bSDave Hansen * by the calling code. 46865ac2e9bSDave Hansen */ 46999aa22d0SYu-cheng Yu int using_compacted_format(void) 47065ac2e9bSDave Hansen { 471782511b0SBorislav Petkov return boot_cpu_has(X86_FEATURE_XSAVES); 47265ac2e9bSDave Hansen } 47365ac2e9bSDave Hansen 474e63e5d5cSEric Biggers /* Validate an xstate header supplied by userspace (ptrace or sigreturn) */ 475e63e5d5cSEric Biggers int validate_xstate_header(const struct xstate_header *hdr) 476e63e5d5cSEric Biggers { 477e63e5d5cSEric Biggers /* No unknown or supervisor features may be set */ 478e63e5d5cSEric Biggers if (hdr->xfeatures & (~xfeatures_mask | XFEATURE_MASK_SUPERVISOR)) 479e63e5d5cSEric Biggers return -EINVAL; 480e63e5d5cSEric Biggers 481e63e5d5cSEric Biggers /* Userspace must use the uncompacted format */ 482e63e5d5cSEric Biggers if (hdr->xcomp_bv) 483e63e5d5cSEric Biggers return -EINVAL; 484e63e5d5cSEric Biggers 485e63e5d5cSEric Biggers /* 486e63e5d5cSEric Biggers * If 'reserved' is shrunken to add a new field, make sure to validate 487e63e5d5cSEric Biggers * that new field here! 488e63e5d5cSEric Biggers */ 489e63e5d5cSEric Biggers BUILD_BUG_ON(sizeof(hdr->reserved) != 48); 490e63e5d5cSEric Biggers 491e63e5d5cSEric Biggers /* No reserved bits may be set */ 492e63e5d5cSEric Biggers if (memchr_inv(hdr->reserved, 0, sizeof(hdr->reserved))) 493e63e5d5cSEric Biggers return -EINVAL; 494e63e5d5cSEric Biggers 495e63e5d5cSEric Biggers return 0; 496e63e5d5cSEric Biggers } 497e63e5d5cSEric Biggers 49865ac2e9bSDave Hansen static void __xstate_dump_leaves(void) 49965ac2e9bSDave Hansen { 50065ac2e9bSDave Hansen int i; 50165ac2e9bSDave Hansen u32 eax, ebx, ecx, edx; 50265ac2e9bSDave Hansen static int should_dump = 1; 50365ac2e9bSDave Hansen 50465ac2e9bSDave Hansen if (!should_dump) 50565ac2e9bSDave Hansen return; 50665ac2e9bSDave Hansen should_dump = 0; 50765ac2e9bSDave Hansen /* 50865ac2e9bSDave Hansen * Dump out a few leaves past the ones that we support 50965ac2e9bSDave Hansen * just in case there are some goodies up there 51065ac2e9bSDave Hansen */ 51165ac2e9bSDave Hansen for (i = 0; i < XFEATURE_MAX + 10; i++) { 51265ac2e9bSDave Hansen cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx); 51365ac2e9bSDave Hansen pr_warn("CPUID[%02x, %02x]: eax=%08x ebx=%08x ecx=%08x edx=%08x\n", 51465ac2e9bSDave Hansen XSTATE_CPUID, i, eax, ebx, ecx, edx); 51565ac2e9bSDave Hansen } 51665ac2e9bSDave Hansen } 51765ac2e9bSDave Hansen 51865ac2e9bSDave Hansen #define XSTATE_WARN_ON(x) do { \ 51965ac2e9bSDave Hansen if (WARN_ONCE(x, "XSAVE consistency problem, dumping leaves")) { \ 52065ac2e9bSDave Hansen __xstate_dump_leaves(); \ 52165ac2e9bSDave Hansen } \ 52265ac2e9bSDave Hansen } while (0) 52365ac2e9bSDave Hansen 524ef78f2a4SDave Hansen #define XCHECK_SZ(sz, nr, nr_macro, __struct) do { \ 525ef78f2a4SDave Hansen if ((nr == nr_macro) && \ 526ef78f2a4SDave Hansen WARN_ONCE(sz != sizeof(__struct), \ 527ef78f2a4SDave Hansen "%s: struct is %zu bytes, cpu state %d bytes\n", \ 528ef78f2a4SDave Hansen __stringify(nr_macro), sizeof(__struct), sz)) { \ 529ef78f2a4SDave Hansen __xstate_dump_leaves(); \ 530ef78f2a4SDave Hansen } \ 531ef78f2a4SDave Hansen } while (0) 532ef78f2a4SDave Hansen 533ef78f2a4SDave Hansen /* 534ef78f2a4SDave Hansen * We have a C struct for each 'xstate'. We need to ensure 535ef78f2a4SDave Hansen * that our software representation matches what the CPU 536ef78f2a4SDave Hansen * tells us about the state's size. 537ef78f2a4SDave Hansen */ 538ef78f2a4SDave Hansen static void check_xstate_against_struct(int nr) 539ef78f2a4SDave Hansen { 540ef78f2a4SDave Hansen /* 541ef78f2a4SDave Hansen * Ask the CPU for the size of the state. 542ef78f2a4SDave Hansen */ 543ef78f2a4SDave Hansen int sz = xfeature_size(nr); 544ef78f2a4SDave Hansen /* 545ef78f2a4SDave Hansen * Match each CPU state with the corresponding software 546ef78f2a4SDave Hansen * structure. 547ef78f2a4SDave Hansen */ 548ef78f2a4SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_YMM, struct ymmh_struct); 549ef78f2a4SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_BNDREGS, struct mpx_bndreg_state); 550ef78f2a4SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_BNDCSR, struct mpx_bndcsr_state); 551ef78f2a4SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_OPMASK, struct avx_512_opmask_state); 552ef78f2a4SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_ZMM_Hi256, struct avx_512_zmm_uppers_state); 553ef78f2a4SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_Hi16_ZMM, struct avx_512_hi16_state); 554c8df4009SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_PKRU, struct pkru_state); 555ef78f2a4SDave Hansen 556ef78f2a4SDave Hansen /* 557ef78f2a4SDave Hansen * Make *SURE* to add any feature numbers in below if 558ef78f2a4SDave Hansen * there are "holes" in the xsave state component 559ef78f2a4SDave Hansen * numbers. 560ef78f2a4SDave Hansen */ 561ef78f2a4SDave Hansen if ((nr < XFEATURE_YMM) || 5621f96b1efSDave Hansen (nr >= XFEATURE_MAX) || 5631f96b1efSDave Hansen (nr == XFEATURE_PT_UNIMPLEMENTED_SO_FAR)) { 564ef78f2a4SDave Hansen WARN_ONCE(1, "no structure for xstate: %d\n", nr); 565ef78f2a4SDave Hansen XSTATE_WARN_ON(1); 566ef78f2a4SDave Hansen } 567ef78f2a4SDave Hansen } 568ef78f2a4SDave Hansen 56965ac2e9bSDave Hansen /* 57065ac2e9bSDave Hansen * This essentially double-checks what the cpu told us about 57165ac2e9bSDave Hansen * how large the XSAVE buffer needs to be. We are recalculating 57265ac2e9bSDave Hansen * it to be safe. 57365ac2e9bSDave Hansen */ 57465ac2e9bSDave Hansen static void do_extra_xstate_size_checks(void) 57565ac2e9bSDave Hansen { 57665ac2e9bSDave Hansen int paranoid_xstate_size = FXSAVE_SIZE + XSAVE_HDR_SIZE; 57765ac2e9bSDave Hansen int i; 57865ac2e9bSDave Hansen 57965ac2e9bSDave Hansen for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { 58065ac2e9bSDave Hansen if (!xfeature_enabled(i)) 58165ac2e9bSDave Hansen continue; 582ef78f2a4SDave Hansen 583ef78f2a4SDave Hansen check_xstate_against_struct(i); 58465ac2e9bSDave Hansen /* 58565ac2e9bSDave Hansen * Supervisor state components can be managed only by 58665ac2e9bSDave Hansen * XSAVES, which is compacted-format only. 58765ac2e9bSDave Hansen */ 58865ac2e9bSDave Hansen if (!using_compacted_format()) 58965ac2e9bSDave Hansen XSTATE_WARN_ON(xfeature_is_supervisor(i)); 59065ac2e9bSDave Hansen 59165ac2e9bSDave Hansen /* Align from the end of the previous feature */ 59265ac2e9bSDave Hansen if (xfeature_is_aligned(i)) 59365ac2e9bSDave Hansen paranoid_xstate_size = ALIGN(paranoid_xstate_size, 64); 59465ac2e9bSDave Hansen /* 59565ac2e9bSDave Hansen * The offset of a given state in the non-compacted 59665ac2e9bSDave Hansen * format is given to us in a CPUID leaf. We check 59765ac2e9bSDave Hansen * them for being ordered (increasing offsets) in 59865ac2e9bSDave Hansen * setup_xstate_features(). 59965ac2e9bSDave Hansen */ 60065ac2e9bSDave Hansen if (!using_compacted_format()) 60165ac2e9bSDave Hansen paranoid_xstate_size = xfeature_uncompacted_offset(i); 60265ac2e9bSDave Hansen /* 60365ac2e9bSDave Hansen * The compacted-format offset always depends on where 60465ac2e9bSDave Hansen * the previous state ended. 60565ac2e9bSDave Hansen */ 60665ac2e9bSDave Hansen paranoid_xstate_size += xfeature_size(i); 60765ac2e9bSDave Hansen } 608bf15a8cfSFenghua Yu XSTATE_WARN_ON(paranoid_xstate_size != fpu_kernel_xstate_size); 60965ac2e9bSDave Hansen } 61065ac2e9bSDave Hansen 611a1141e0bSFenghua Yu 61262784854SIngo Molnar /* 613a1141e0bSFenghua Yu * Get total size of enabled xstates in XCR0/xfeatures_mask. 61465ac2e9bSDave Hansen * 61565ac2e9bSDave Hansen * Note the SDM's wording here. "sub-function 0" only enumerates 61665ac2e9bSDave Hansen * the size of the *user* states. If we use it to size a buffer 61765ac2e9bSDave Hansen * that we use 'XSAVES' on, we could potentially overflow the 61865ac2e9bSDave Hansen * buffer because 'XSAVES' saves system states too. 61965ac2e9bSDave Hansen * 62065ac2e9bSDave Hansen * Note that we do not currently set any bits on IA32_XSS so 62165ac2e9bSDave Hansen * 'XCR0 | IA32_XSS == XCR0' for now. 62262784854SIngo Molnar */ 623a1141e0bSFenghua Yu static unsigned int __init get_xsaves_size(void) 62462784854SIngo Molnar { 62562784854SIngo Molnar unsigned int eax, ebx, ecx, edx; 62665ac2e9bSDave Hansen /* 62765ac2e9bSDave Hansen * - CPUID function 0DH, sub-function 1: 62865ac2e9bSDave Hansen * EBX enumerates the size (in bytes) required by 62965ac2e9bSDave Hansen * the XSAVES instruction for an XSAVE area 63065ac2e9bSDave Hansen * containing all the state components 63165ac2e9bSDave Hansen * corresponding to bits currently set in 63265ac2e9bSDave Hansen * XCR0 | IA32_XSS. 63365ac2e9bSDave Hansen */ 63465ac2e9bSDave Hansen cpuid_count(XSTATE_CPUID, 1, &eax, &ebx, &ecx, &edx); 635a1141e0bSFenghua Yu return ebx; 63662784854SIngo Molnar } 637a1141e0bSFenghua Yu 638a1141e0bSFenghua Yu static unsigned int __init get_xsave_size(void) 639a1141e0bSFenghua Yu { 640a1141e0bSFenghua Yu unsigned int eax, ebx, ecx, edx; 641a1141e0bSFenghua Yu /* 642a1141e0bSFenghua Yu * - CPUID function 0DH, sub-function 0: 643a1141e0bSFenghua Yu * EBX enumerates the size (in bytes) required by 644a1141e0bSFenghua Yu * the XSAVE instruction for an XSAVE area 645a1141e0bSFenghua Yu * containing all the *user* state components 646a1141e0bSFenghua Yu * corresponding to bits currently set in XCR0. 647a1141e0bSFenghua Yu */ 648a1141e0bSFenghua Yu cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx); 649a1141e0bSFenghua Yu return ebx; 6504109ca06SDave Hansen } 6514109ca06SDave Hansen 6524109ca06SDave Hansen /* 6534109ca06SDave Hansen * Will the runtime-enumerated 'xstate_size' fit in the init 6544109ca06SDave Hansen * task's statically-allocated buffer? 6554109ca06SDave Hansen */ 6564109ca06SDave Hansen static bool is_supported_xstate_size(unsigned int test_xstate_size) 6574109ca06SDave Hansen { 6584109ca06SDave Hansen if (test_xstate_size <= sizeof(union fpregs_state)) 6594109ca06SDave Hansen return true; 6604109ca06SDave Hansen 6614109ca06SDave Hansen pr_warn("x86/fpu: xstate buffer too small (%zu < %d), disabling xsave\n", 6624109ca06SDave Hansen sizeof(union fpregs_state), test_xstate_size); 6634109ca06SDave Hansen return false; 6644109ca06SDave Hansen } 6654109ca06SDave Hansen 666653a561bSSergey Senozhatsky static int __init init_xstate_size(void) 6674109ca06SDave Hansen { 6684109ca06SDave Hansen /* Recompute the context size for enabled features: */ 669a1141e0bSFenghua Yu unsigned int possible_xstate_size; 670a1141e0bSFenghua Yu unsigned int xsave_size; 671a1141e0bSFenghua Yu 672a1141e0bSFenghua Yu xsave_size = get_xsave_size(); 673a1141e0bSFenghua Yu 674a1141e0bSFenghua Yu if (boot_cpu_has(X86_FEATURE_XSAVES)) 675a1141e0bSFenghua Yu possible_xstate_size = get_xsaves_size(); 676a1141e0bSFenghua Yu else 677a1141e0bSFenghua Yu possible_xstate_size = xsave_size; 6784109ca06SDave Hansen 6794109ca06SDave Hansen /* Ensure we have the space to store all enabled: */ 6804109ca06SDave Hansen if (!is_supported_xstate_size(possible_xstate_size)) 6814109ca06SDave Hansen return -EINVAL; 6824109ca06SDave Hansen 6834109ca06SDave Hansen /* 6844109ca06SDave Hansen * The size is OK, we are definitely going to use xsave, 6854109ca06SDave Hansen * make it known to the world that we need more space. 6864109ca06SDave Hansen */ 687bf15a8cfSFenghua Yu fpu_kernel_xstate_size = possible_xstate_size; 68865ac2e9bSDave Hansen do_extra_xstate_size_checks(); 689a1141e0bSFenghua Yu 690a1141e0bSFenghua Yu /* 691a1141e0bSFenghua Yu * User space is always in standard format. 692a1141e0bSFenghua Yu */ 693a1141e0bSFenghua Yu fpu_user_xstate_size = xsave_size; 6944109ca06SDave Hansen return 0; 6954109ca06SDave Hansen } 6964109ca06SDave Hansen 697d91cab78SDave Hansen /* 698d91cab78SDave Hansen * We enabled the XSAVE hardware, but something went wrong and 699d91cab78SDave Hansen * we can not use it. Disable it. 700d91cab78SDave Hansen */ 701d91cab78SDave Hansen static void fpu__init_disable_system_xstate(void) 7024109ca06SDave Hansen { 7034109ca06SDave Hansen xfeatures_mask = 0; 7044109ca06SDave Hansen cr4_clear_bits(X86_CR4_OSXSAVE); 7057891bc0aSSebastian Andrzej Siewior setup_clear_cpu_cap(X86_FEATURE_XSAVE); 70662784854SIngo Molnar } 70762784854SIngo Molnar 70862784854SIngo Molnar /* 70962784854SIngo Molnar * Enable and initialize the xsave feature. 71062784854SIngo Molnar * Called once per system bootup. 71162784854SIngo Molnar */ 71232231879SIngo Molnar void __init fpu__init_system_xstate(void) 71362784854SIngo Molnar { 71462784854SIngo Molnar unsigned int eax, ebx, ecx, edx; 715e49a449bSRasmus Villemoes static int on_boot_cpu __initdata = 1; 7164109ca06SDave Hansen int err; 717ccb18db2SAndi Kleen int i; 718e97131a8SIngo Molnar 719e97131a8SIngo Molnar WARN_ON_FPU(!on_boot_cpu); 720e97131a8SIngo Molnar on_boot_cpu = 0; 72162784854SIngo Molnar 7229170fb40SAndy Lutomirski if (!boot_cpu_has(X86_FEATURE_FPU)) { 7239170fb40SAndy Lutomirski pr_info("x86/fpu: No FPU detected\n"); 7249170fb40SAndy Lutomirski return; 7259170fb40SAndy Lutomirski } 7269170fb40SAndy Lutomirski 727d366bf7eSBorislav Petkov if (!boot_cpu_has(X86_FEATURE_XSAVE)) { 7289170fb40SAndy Lutomirski pr_info("x86/fpu: x87 FPU will use %s\n", 7299170fb40SAndy Lutomirski boot_cpu_has(X86_FEATURE_FXSR) ? "FXSAVE" : "FSAVE"); 73062784854SIngo Molnar return; 73162784854SIngo Molnar } 73262784854SIngo Molnar 73362784854SIngo Molnar if (boot_cpu_data.cpuid_level < XSTATE_CPUID) { 734e97131a8SIngo Molnar WARN_ON_FPU(1); 73562784854SIngo Molnar return; 73662784854SIngo Molnar } 73762784854SIngo Molnar 73862784854SIngo Molnar cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx); 73962784854SIngo Molnar xfeatures_mask = eax + ((u64)edx << 32); 74062784854SIngo Molnar 741d91cab78SDave Hansen if ((xfeatures_mask & XFEATURE_MASK_FPSSE) != XFEATURE_MASK_FPSSE) { 742ec3ed4a2SDave Hansen /* 743ec3ed4a2SDave Hansen * This indicates that something really unexpected happened 744ec3ed4a2SDave Hansen * with the enumeration. Disable XSAVE and try to continue 745ec3ed4a2SDave Hansen * booting without it. This is too early to BUG(). 746ec3ed4a2SDave Hansen */ 74762784854SIngo Molnar pr_err("x86/fpu: FP/SSE not present amongst the CPU's xstate features: 0x%llx.\n", xfeatures_mask); 748ec3ed4a2SDave Hansen goto out_disable; 74962784854SIngo Molnar } 75062784854SIngo Molnar 751ccb18db2SAndi Kleen /* 752ccb18db2SAndi Kleen * Clear XSAVE features that are disabled in the normal CPUID. 753ccb18db2SAndi Kleen */ 754ccb18db2SAndi Kleen for (i = 0; i < ARRAY_SIZE(xsave_cpuid_features); i++) { 755ccb18db2SAndi Kleen if (!boot_cpu_has(xsave_cpuid_features[i])) 756ccb18db2SAndi Kleen xfeatures_mask &= ~BIT(i); 757ccb18db2SAndi Kleen } 758ccb18db2SAndi Kleen 759a5fe93a5Syu-cheng yu xfeatures_mask &= fpu__get_supported_xfeatures_mask(); 76062784854SIngo Molnar 76162784854SIngo Molnar /* Enable xstate instructions to be able to continue with initialization: */ 76262784854SIngo Molnar fpu__init_cpu_xstate(); 7634109ca06SDave Hansen err = init_xstate_size(); 764ec3ed4a2SDave Hansen if (err) 765ec3ed4a2SDave Hansen goto out_disable; 76662784854SIngo Molnar 76791c3dba7SYu-cheng Yu /* 76891c3dba7SYu-cheng Yu * Update info used for ptrace frames; use standard-format size and no 76991c3dba7SYu-cheng Yu * supervisor xstates: 77091c3dba7SYu-cheng Yu */ 77191c3dba7SYu-cheng Yu update_regset_xstate_info(fpu_user_xstate_size, xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR); 77291c3dba7SYu-cheng Yu 773b992c660SIngo Molnar fpu__init_prepare_fx_sw_frame(); 77462784854SIngo Molnar setup_init_fpu_buf(); 77549a91d61SYu-cheng Yu setup_xstate_comp_offsets(); 776996952e0SYu-cheng Yu print_xstate_offset_size(); 77762784854SIngo Molnar 778b0815359SDave Hansen pr_info("x86/fpu: Enabled xstate features 0x%llx, context size is %d bytes, using '%s' format.\n", 77962784854SIngo Molnar xfeatures_mask, 780bf15a8cfSFenghua Yu fpu_kernel_xstate_size, 781782511b0SBorislav Petkov boot_cpu_has(X86_FEATURE_XSAVES) ? "compacted" : "standard"); 782ec3ed4a2SDave Hansen return; 783ec3ed4a2SDave Hansen 784ec3ed4a2SDave Hansen out_disable: 785ec3ed4a2SDave Hansen /* something went wrong, try to boot without any XSAVE support */ 786ec3ed4a2SDave Hansen fpu__init_disable_system_xstate(); 78762784854SIngo Molnar } 78862784854SIngo Molnar 78962784854SIngo Molnar /* 79062784854SIngo Molnar * Restore minimal FPU state after suspend: 79162784854SIngo Molnar */ 79262784854SIngo Molnar void fpu__resume_cpu(void) 79362784854SIngo Molnar { 79462784854SIngo Molnar /* 79562784854SIngo Molnar * Restore XCR0 on xsave capable CPUs: 79662784854SIngo Molnar */ 797d366bf7eSBorislav Petkov if (boot_cpu_has(X86_FEATURE_XSAVE)) 79862784854SIngo Molnar xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask); 79962784854SIngo Molnar } 80062784854SIngo Molnar 80162784854SIngo Molnar /* 80207baeb04SSebastian Andrzej Siewior * Given an xstate feature nr, calculate where in the xsave 803b8b9b6baSDave Hansen * buffer the state is. Callers should ensure that the buffer 804b8b9b6baSDave Hansen * is valid. 805b8b9b6baSDave Hansen */ 80607baeb04SSebastian Andrzej Siewior static void *__raw_xsave_addr(struct xregs_state *xsave, int xfeature_nr) 807b8b9b6baSDave Hansen { 80807baeb04SSebastian Andrzej Siewior if (!xfeature_enabled(xfeature_nr)) { 8095060b915SYu-cheng Yu WARN_ON_FPU(1); 8105060b915SYu-cheng Yu return NULL; 8115060b915SYu-cheng Yu } 8125060b915SYu-cheng Yu 81307baeb04SSebastian Andrzej Siewior return (void *)xsave + xstate_comp_offsets[xfeature_nr]; 814b8b9b6baSDave Hansen } 815b8b9b6baSDave Hansen /* 81662784854SIngo Molnar * Given the xsave area and a state inside, this function returns the 81762784854SIngo Molnar * address of the state. 81862784854SIngo Molnar * 81962784854SIngo Molnar * This is the API that is called to get xstate address in either 82062784854SIngo Molnar * standard format or compacted format of xsave area. 82162784854SIngo Molnar * 8220c4109beSDave Hansen * Note that if there is no data for the field in the xsave buffer 8230c4109beSDave Hansen * this will return NULL. 8240c4109beSDave Hansen * 82562784854SIngo Molnar * Inputs: 8260c4109beSDave Hansen * xstate: the thread's storage area for all FPU data 827abd16d68SSebastian Andrzej Siewior * xfeature_nr: state which is defined in xsave.h (e.g. XFEATURE_FP, 828abd16d68SSebastian Andrzej Siewior * XFEATURE_SSE, etc...) 82962784854SIngo Molnar * Output: 8300c4109beSDave Hansen * address of the state in the xsave area, or NULL if the 8310c4109beSDave Hansen * field is not present in the xsave buffer. 83262784854SIngo Molnar */ 833abd16d68SSebastian Andrzej Siewior void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr) 83462784854SIngo Molnar { 8350c4109beSDave Hansen /* 8360c4109beSDave Hansen * Do we even *have* xsave state? 8370c4109beSDave Hansen */ 8380c4109beSDave Hansen if (!boot_cpu_has(X86_FEATURE_XSAVE)) 83962784854SIngo Molnar return NULL; 84062784854SIngo Molnar 8410c4109beSDave Hansen /* 8420c4109beSDave Hansen * We should not ever be requesting features that we 84358db1037SCyrill Gorcunov * have not enabled. Remember that xfeatures_mask is 8440c4109beSDave Hansen * what we write to the XCR0 register. 8450c4109beSDave Hansen */ 846abd16d68SSebastian Andrzej Siewior WARN_ONCE(!(xfeatures_mask & BIT_ULL(xfeature_nr)), 8470c4109beSDave Hansen "get of unsupported state"); 8480c4109beSDave Hansen /* 8490c4109beSDave Hansen * This assumes the last 'xsave*' instruction to 850abd16d68SSebastian Andrzej Siewior * have requested that 'xfeature_nr' be saved. 8510c4109beSDave Hansen * If it did not, we might be seeing and old value 8520c4109beSDave Hansen * of the field in the buffer. 8530c4109beSDave Hansen * 8540c4109beSDave Hansen * This can happen because the last 'xsave' did not 8550c4109beSDave Hansen * request that this feature be saved (unlikely) 8560c4109beSDave Hansen * or because the "init optimization" caused it 8570c4109beSDave Hansen * to not be saved. 8580c4109beSDave Hansen */ 859abd16d68SSebastian Andrzej Siewior if (!(xsave->header.xfeatures & BIT_ULL(xfeature_nr))) 8600c4109beSDave Hansen return NULL; 8610c4109beSDave Hansen 86207baeb04SSebastian Andrzej Siewior return __raw_xsave_addr(xsave, xfeature_nr); 86362784854SIngo Molnar } 86462784854SIngo Molnar EXPORT_SYMBOL_GPL(get_xsave_addr); 86504cd027bSDave Hansen 86604cd027bSDave Hansen /* 86704cd027bSDave Hansen * This wraps up the common operations that need to occur when retrieving 86804cd027bSDave Hansen * data from xsave state. It first ensures that the current task was 86904cd027bSDave Hansen * using the FPU and retrieves the data in to a buffer. It then calculates 87004cd027bSDave Hansen * the offset of the requested field in the buffer. 87104cd027bSDave Hansen * 87204cd027bSDave Hansen * This function is safe to call whether the FPU is in use or not. 87304cd027bSDave Hansen * 87404cd027bSDave Hansen * Note that this only works on the current task. 87504cd027bSDave Hansen * 87604cd027bSDave Hansen * Inputs: 877abd16d68SSebastian Andrzej Siewior * @xfeature_nr: state which is defined in xsave.h (e.g. XFEATURE_FP, 878abd16d68SSebastian Andrzej Siewior * XFEATURE_SSE, etc...) 87904cd027bSDave Hansen * Output: 88004cd027bSDave Hansen * address of the state in the xsave area or NULL if the state 88104cd027bSDave Hansen * is not present or is in its 'init state'. 88204cd027bSDave Hansen */ 883abd16d68SSebastian Andrzej Siewior const void *get_xsave_field_ptr(int xfeature_nr) 88404cd027bSDave Hansen { 88504cd027bSDave Hansen struct fpu *fpu = ¤t->thread.fpu; 88604cd027bSDave Hansen 88704cd027bSDave Hansen /* 88804cd027bSDave Hansen * fpu__save() takes the CPU's xstate registers 88904cd027bSDave Hansen * and saves them off to the 'fpu memory buffer. 89004cd027bSDave Hansen */ 89104cd027bSDave Hansen fpu__save(fpu); 89204cd027bSDave Hansen 893abd16d68SSebastian Andrzej Siewior return get_xsave_addr(&fpu->state.xsave, xfeature_nr); 89404cd027bSDave Hansen } 895b8b9b6baSDave Hansen 896e8c24d3aSDave Hansen #ifdef CONFIG_ARCH_HAS_PKEYS 897e8c24d3aSDave Hansen 89884594296SDave Hansen /* 899b79daf85SDave Hansen * This will go out and modify PKRU register to set the access 900b79daf85SDave Hansen * rights for @pkey to @init_val. 90184594296SDave Hansen */ 90284594296SDave Hansen int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 90384594296SDave Hansen unsigned long init_val) 90484594296SDave Hansen { 905b79daf85SDave Hansen u32 old_pkru; 90684594296SDave Hansen int pkey_shift = (pkey * PKRU_BITS_PER_PKEY); 90784594296SDave Hansen u32 new_pkru_bits = 0; 90884594296SDave Hansen 90984594296SDave Hansen /* 91084594296SDave Hansen * This check implies XSAVE support. OSPKE only gets 91184594296SDave Hansen * set if we enable XSAVE and we enable PKU in XCR0. 91284594296SDave Hansen */ 91384594296SDave Hansen if (!boot_cpu_has(X86_FEATURE_OSPKE)) 91484594296SDave Hansen return -EINVAL; 91584594296SDave Hansen 91616171bffSDave Hansen /* 91716171bffSDave Hansen * This code should only be called with valid 'pkey' 91816171bffSDave Hansen * values originating from in-kernel users. Complain 91916171bffSDave Hansen * if a bad value is observed. 92016171bffSDave Hansen */ 92116171bffSDave Hansen WARN_ON_ONCE(pkey >= arch_max_pkey()); 92216171bffSDave Hansen 92391c3dba7SYu-cheng Yu /* Set the bits we need in PKRU: */ 92484594296SDave Hansen if (init_val & PKEY_DISABLE_ACCESS) 92584594296SDave Hansen new_pkru_bits |= PKRU_AD_BIT; 92684594296SDave Hansen if (init_val & PKEY_DISABLE_WRITE) 92784594296SDave Hansen new_pkru_bits |= PKRU_WD_BIT; 92884594296SDave Hansen 92991c3dba7SYu-cheng Yu /* Shift the bits in to the correct place in PKRU for pkey: */ 93084594296SDave Hansen new_pkru_bits <<= pkey_shift; 93184594296SDave Hansen 932b79daf85SDave Hansen /* Get old PKRU and mask off any old bits in place: */ 933b79daf85SDave Hansen old_pkru = read_pkru(); 934b79daf85SDave Hansen old_pkru &= ~((PKRU_AD_BIT|PKRU_WD_BIT) << pkey_shift); 93584594296SDave Hansen 936b79daf85SDave Hansen /* Write old part along with new part: */ 937b79daf85SDave Hansen write_pkru(old_pkru | new_pkru_bits); 93891c3dba7SYu-cheng Yu 93991c3dba7SYu-cheng Yu return 0; 94091c3dba7SYu-cheng Yu } 941e8c24d3aSDave Hansen #endif /* ! CONFIG_ARCH_HAS_PKEYS */ 94291c3dba7SYu-cheng Yu 94391c3dba7SYu-cheng Yu /* 9440852b374SRik van Riel * Weird legacy quirk: SSE and YMM states store information in the 9450852b374SRik van Riel * MXCSR and MXCSR_FLAGS fields of the FP area. That means if the FP 9460852b374SRik van Riel * area is marked as unused in the xfeatures header, we need to copy 9470852b374SRik van Riel * MXCSR and MXCSR_FLAGS if either SSE or YMM are in use. 9480852b374SRik van Riel */ 9490852b374SRik van Riel static inline bool xfeatures_mxcsr_quirk(u64 xfeatures) 9500852b374SRik van Riel { 9510852b374SRik van Riel if (!(xfeatures & (XFEATURE_MASK_SSE|XFEATURE_MASK_YMM))) 9524f8cef59Skbuild test robot return false; 9530852b374SRik van Riel 9540852b374SRik van Riel if (xfeatures & XFEATURE_MASK_FP) 9554f8cef59Skbuild test robot return false; 9560852b374SRik van Riel 9574f8cef59Skbuild test robot return true; 9580852b374SRik van Riel } 9590852b374SRik van Riel 9609e463654SAl Viro static void fill_gap(unsigned to, void **kbuf, unsigned *pos, unsigned *count) 961f0d4f30aSIngo Molnar { 9629e463654SAl Viro if (*pos < to) { 9639e463654SAl Viro unsigned size = to - *pos; 964f0d4f30aSIngo Molnar 9659e463654SAl Viro if (size > *count) 9669e463654SAl Viro size = *count; 9679e463654SAl Viro memcpy(*kbuf, (void *)&init_fpstate.xsave + *pos, size); 9689e463654SAl Viro *kbuf += size; 9699e463654SAl Viro *pos += size; 9709e463654SAl Viro *count -= size; 9719e463654SAl Viro } 9729e463654SAl Viro } 9739e463654SAl Viro 9749e463654SAl Viro static void copy_part(unsigned offset, unsigned size, void *from, 9759e463654SAl Viro void **kbuf, unsigned *pos, unsigned *count) 9769e463654SAl Viro { 9779e463654SAl Viro fill_gap(offset, kbuf, pos, count); 9789e463654SAl Viro if (size > *count) 9799e463654SAl Viro size = *count; 9809e463654SAl Viro if (size) { 9819e463654SAl Viro memcpy(*kbuf, from, size); 9829e463654SAl Viro *kbuf += size; 9839e463654SAl Viro *pos += size; 9849e463654SAl Viro *count -= size; 985f0d4f30aSIngo Molnar } 986f0d4f30aSIngo Molnar } 987f0d4f30aSIngo Molnar 988f0d4f30aSIngo Molnar /* 989f0d4f30aSIngo Molnar * Convert from kernel XSAVES compacted format to standard format and copy 990f0d4f30aSIngo Molnar * to a kernel-space ptrace buffer. 991f0d4f30aSIngo Molnar * 992f0d4f30aSIngo Molnar * It supports partial copy but pos always starts from zero. This is called 993f0d4f30aSIngo Molnar * from xstateregs_get() and there we check the CPU has XSAVES. 994f0d4f30aSIngo Molnar */ 99556583c9aSIngo Molnar int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int offset_start, unsigned int size_total) 996f0d4f30aSIngo Molnar { 997f0d4f30aSIngo Molnar struct xstate_header header; 9989e463654SAl Viro const unsigned off_mxcsr = offsetof(struct fxregs_state, mxcsr); 9999e463654SAl Viro unsigned count = size_total; 10008c0817f4SIngo Molnar int i; 1001f0d4f30aSIngo Molnar 1002f0d4f30aSIngo Molnar /* 1003f0d4f30aSIngo Molnar * Currently copy_regset_to_user() starts from pos 0: 1004f0d4f30aSIngo Molnar */ 100556583c9aSIngo Molnar if (unlikely(offset_start != 0)) 1006f0d4f30aSIngo Molnar return -EFAULT; 1007f0d4f30aSIngo Molnar 1008f0d4f30aSIngo Molnar /* 1009f0d4f30aSIngo Molnar * The destination is a ptrace buffer; we put in only user xstates: 1010f0d4f30aSIngo Molnar */ 1011f0d4f30aSIngo Molnar memset(&header, 0, sizeof(header)); 1012f0d4f30aSIngo Molnar header.xfeatures = xsave->header.xfeatures; 1013f0d4f30aSIngo Molnar header.xfeatures &= ~XFEATURE_MASK_SUPERVISOR; 1014f0d4f30aSIngo Molnar 10159e463654SAl Viro if (header.xfeatures & XFEATURE_MASK_FP) 10169e463654SAl Viro copy_part(0, off_mxcsr, 10179e463654SAl Viro &xsave->i387, &kbuf, &offset_start, &count); 10189e463654SAl Viro if (header.xfeatures & (XFEATURE_MASK_SSE | XFEATURE_MASK_YMM)) 10199e463654SAl Viro copy_part(off_mxcsr, MXCSR_AND_FLAGS_SIZE, 10209e463654SAl Viro &xsave->i387.mxcsr, &kbuf, &offset_start, &count); 10219e463654SAl Viro if (header.xfeatures & XFEATURE_MASK_FP) 10229e463654SAl Viro copy_part(offsetof(struct fxregs_state, st_space), 128, 10239e463654SAl Viro &xsave->i387.st_space, &kbuf, &offset_start, &count); 10249e463654SAl Viro if (header.xfeatures & XFEATURE_MASK_SSE) 10259e463654SAl Viro copy_part(xstate_offsets[XFEATURE_MASK_SSE], 256, 10269e463654SAl Viro &xsave->i387.xmm_space, &kbuf, &offset_start, &count); 10279e463654SAl Viro /* 10289e463654SAl Viro * Fill xsave->i387.sw_reserved value for ptrace frame: 10299e463654SAl Viro */ 10309e463654SAl Viro copy_part(offsetof(struct fxregs_state, sw_reserved), 48, 10319e463654SAl Viro xstate_fx_sw_bytes, &kbuf, &offset_start, &count); 1032f0d4f30aSIngo Molnar /* 1033f0d4f30aSIngo Molnar * Copy xregs_state->header: 1034f0d4f30aSIngo Molnar */ 10359e463654SAl Viro copy_part(offsetof(struct xregs_state, header), sizeof(header), 10369e463654SAl Viro &header, &kbuf, &offset_start, &count); 1037f0d4f30aSIngo Molnar 10389e463654SAl Viro for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { 1039f0d4f30aSIngo Molnar /* 1040f0d4f30aSIngo Molnar * Copy only in-use xstates: 1041f0d4f30aSIngo Molnar */ 1042f0d4f30aSIngo Molnar if ((header.xfeatures >> i) & 1) { 104307baeb04SSebastian Andrzej Siewior void *src = __raw_xsave_addr(xsave, i); 1044f0d4f30aSIngo Molnar 10459e463654SAl Viro copy_part(xstate_offsets[i], xstate_sizes[i], 10469e463654SAl Viro src, &kbuf, &offset_start, &count); 1047f0d4f30aSIngo Molnar } 1048f0d4f30aSIngo Molnar 1049f0d4f30aSIngo Molnar } 10509e463654SAl Viro fill_gap(size_total, &kbuf, &offset_start, &count); 1051f0d4f30aSIngo Molnar 1052f0d4f30aSIngo Molnar return 0; 1053f0d4f30aSIngo Molnar } 1054f0d4f30aSIngo Molnar 1055f0d4f30aSIngo Molnar static inline int 10566ff15f8dSIngo Molnar __copy_xstate_to_user(void __user *ubuf, const void *data, unsigned int offset, unsigned int size, unsigned int size_total) 105791c3dba7SYu-cheng Yu { 105856583c9aSIngo Molnar if (!size) 105991c3dba7SYu-cheng Yu return 0; 106091c3dba7SYu-cheng Yu 10616ff15f8dSIngo Molnar if (offset < size_total) { 10626ff15f8dSIngo Molnar unsigned int copy = min(size, size_total - offset); 106391c3dba7SYu-cheng Yu 106456583c9aSIngo Molnar if (__copy_to_user(ubuf + offset, data, copy)) 106591c3dba7SYu-cheng Yu return -EFAULT; 106691c3dba7SYu-cheng Yu } 106791c3dba7SYu-cheng Yu return 0; 106891c3dba7SYu-cheng Yu } 106991c3dba7SYu-cheng Yu 107091c3dba7SYu-cheng Yu /* 107191c3dba7SYu-cheng Yu * Convert from kernel XSAVES compacted format to standard format and copy 1072becb2bb7SIngo Molnar * to a user-space buffer. It supports partial copy but pos always starts from 107391c3dba7SYu-cheng Yu * zero. This is called from xstateregs_get() and there we check the CPU 107491c3dba7SYu-cheng Yu * has XSAVES. 107591c3dba7SYu-cheng Yu */ 107656583c9aSIngo Molnar int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int offset_start, unsigned int size_total) 107791c3dba7SYu-cheng Yu { 107891c3dba7SYu-cheng Yu unsigned int offset, size; 107991c3dba7SYu-cheng Yu int ret, i; 108091c3dba7SYu-cheng Yu struct xstate_header header; 108191c3dba7SYu-cheng Yu 108291c3dba7SYu-cheng Yu /* 108391c3dba7SYu-cheng Yu * Currently copy_regset_to_user() starts from pos 0: 108491c3dba7SYu-cheng Yu */ 108556583c9aSIngo Molnar if (unlikely(offset_start != 0)) 108691c3dba7SYu-cheng Yu return -EFAULT; 108791c3dba7SYu-cheng Yu 108891c3dba7SYu-cheng Yu /* 108991c3dba7SYu-cheng Yu * The destination is a ptrace buffer; we put in only user xstates: 109091c3dba7SYu-cheng Yu */ 109191c3dba7SYu-cheng Yu memset(&header, 0, sizeof(header)); 109291c3dba7SYu-cheng Yu header.xfeatures = xsave->header.xfeatures; 109391c3dba7SYu-cheng Yu header.xfeatures &= ~XFEATURE_MASK_SUPERVISOR; 109491c3dba7SYu-cheng Yu 109591c3dba7SYu-cheng Yu /* 109691c3dba7SYu-cheng Yu * Copy xregs_state->header: 109791c3dba7SYu-cheng Yu */ 109891c3dba7SYu-cheng Yu offset = offsetof(struct xregs_state, header); 109991c3dba7SYu-cheng Yu size = sizeof(header); 110091c3dba7SYu-cheng Yu 110156583c9aSIngo Molnar ret = __copy_xstate_to_user(ubuf, &header, offset, size, size_total); 110291c3dba7SYu-cheng Yu if (ret) 110391c3dba7SYu-cheng Yu return ret; 110491c3dba7SYu-cheng Yu 110591c3dba7SYu-cheng Yu for (i = 0; i < XFEATURE_MAX; i++) { 110691c3dba7SYu-cheng Yu /* 110791c3dba7SYu-cheng Yu * Copy only in-use xstates: 110891c3dba7SYu-cheng Yu */ 110991c3dba7SYu-cheng Yu if ((header.xfeatures >> i) & 1) { 111007baeb04SSebastian Andrzej Siewior void *src = __raw_xsave_addr(xsave, i); 111191c3dba7SYu-cheng Yu 111291c3dba7SYu-cheng Yu offset = xstate_offsets[i]; 111391c3dba7SYu-cheng Yu size = xstate_sizes[i]; 111491c3dba7SYu-cheng Yu 11156ff15f8dSIngo Molnar /* The next component has to fit fully into the output buffer: */ 11166ff15f8dSIngo Molnar if (offset + size > size_total) 11176ff15f8dSIngo Molnar break; 11186ff15f8dSIngo Molnar 111956583c9aSIngo Molnar ret = __copy_xstate_to_user(ubuf, src, offset, size, size_total); 112091c3dba7SYu-cheng Yu if (ret) 112191c3dba7SYu-cheng Yu return ret; 112291c3dba7SYu-cheng Yu } 112391c3dba7SYu-cheng Yu 112491c3dba7SYu-cheng Yu } 112591c3dba7SYu-cheng Yu 11260852b374SRik van Riel if (xfeatures_mxcsr_quirk(header.xfeatures)) { 11270852b374SRik van Riel offset = offsetof(struct fxregs_state, mxcsr); 11280852b374SRik van Riel size = MXCSR_AND_FLAGS_SIZE; 11290852b374SRik van Riel __copy_xstate_to_user(ubuf, &xsave->i387.mxcsr, offset, size, size_total); 11300852b374SRik van Riel } 11310852b374SRik van Riel 113291c3dba7SYu-cheng Yu /* 113391c3dba7SYu-cheng Yu * Fill xsave->i387.sw_reserved value for ptrace frame: 113491c3dba7SYu-cheng Yu */ 113591c3dba7SYu-cheng Yu offset = offsetof(struct fxregs_state, sw_reserved); 113691c3dba7SYu-cheng Yu size = sizeof(xstate_fx_sw_bytes); 113791c3dba7SYu-cheng Yu 113856583c9aSIngo Molnar ret = __copy_xstate_to_user(ubuf, xstate_fx_sw_bytes, offset, size, size_total); 113991c3dba7SYu-cheng Yu if (ret) 114091c3dba7SYu-cheng Yu return ret; 114191c3dba7SYu-cheng Yu 114291c3dba7SYu-cheng Yu return 0; 114391c3dba7SYu-cheng Yu } 114491c3dba7SYu-cheng Yu 114591c3dba7SYu-cheng Yu /* 114679fecc2bSIngo Molnar * Convert from a ptrace standard-format kernel buffer to kernel XSAVES format 1147af95774bSEric Biggers * and copy to the target thread. This is called from xstateregs_set(). 114879fecc2bSIngo Molnar */ 11496d7f7da5SIngo Molnar int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf) 115079fecc2bSIngo Molnar { 115179fecc2bSIngo Molnar unsigned int offset, size; 115279fecc2bSIngo Molnar int i; 115380d8ae86SEric Biggers struct xstate_header hdr; 115479fecc2bSIngo Molnar 115579fecc2bSIngo Molnar offset = offsetof(struct xregs_state, header); 115680d8ae86SEric Biggers size = sizeof(hdr); 115779fecc2bSIngo Molnar 115880d8ae86SEric Biggers memcpy(&hdr, kbuf + offset, size); 115979fecc2bSIngo Molnar 1160af95774bSEric Biggers if (validate_xstate_header(&hdr)) 116179fecc2bSIngo Molnar return -EINVAL; 116279fecc2bSIngo Molnar 116379fecc2bSIngo Molnar for (i = 0; i < XFEATURE_MAX; i++) { 116479fecc2bSIngo Molnar u64 mask = ((u64)1 << i); 116579fecc2bSIngo Molnar 1166b89eda48SEric Biggers if (hdr.xfeatures & mask) { 116707baeb04SSebastian Andrzej Siewior void *dst = __raw_xsave_addr(xsave, i); 116879fecc2bSIngo Molnar 116979fecc2bSIngo Molnar offset = xstate_offsets[i]; 117079fecc2bSIngo Molnar size = xstate_sizes[i]; 117179fecc2bSIngo Molnar 117279fecc2bSIngo Molnar memcpy(dst, kbuf + offset, size); 117379fecc2bSIngo Molnar } 117479fecc2bSIngo Molnar } 117579fecc2bSIngo Molnar 1176b89eda48SEric Biggers if (xfeatures_mxcsr_quirk(hdr.xfeatures)) { 11770852b374SRik van Riel offset = offsetof(struct fxregs_state, mxcsr); 11780852b374SRik van Riel size = MXCSR_AND_FLAGS_SIZE; 11790852b374SRik van Riel memcpy(&xsave->i387.mxcsr, kbuf + offset, size); 11800852b374SRik van Riel } 11810852b374SRik van Riel 118279fecc2bSIngo Molnar /* 118379fecc2bSIngo Molnar * The state that came in from userspace was user-state only. 118479fecc2bSIngo Molnar * Mask all the user states out of 'xfeatures': 118579fecc2bSIngo Molnar */ 118679fecc2bSIngo Molnar xsave->header.xfeatures &= XFEATURE_MASK_SUPERVISOR; 118779fecc2bSIngo Molnar 118879fecc2bSIngo Molnar /* 118979fecc2bSIngo Molnar * Add back in the features that came in from userspace: 119079fecc2bSIngo Molnar */ 1191b89eda48SEric Biggers xsave->header.xfeatures |= hdr.xfeatures; 119279fecc2bSIngo Molnar 119379fecc2bSIngo Molnar return 0; 119479fecc2bSIngo Molnar } 119579fecc2bSIngo Molnar 119679fecc2bSIngo Molnar /* 119798c0fad9SEric Biggers * Convert from a ptrace or sigreturn standard-format user-space buffer to 119898c0fad9SEric Biggers * kernel XSAVES format and copy to the target thread. This is called from 119998c0fad9SEric Biggers * xstateregs_set(), as well as potentially from the sigreturn() and 120098c0fad9SEric Biggers * rt_sigreturn() system calls. 120191c3dba7SYu-cheng Yu */ 12026d7f7da5SIngo Molnar int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf) 120391c3dba7SYu-cheng Yu { 120491c3dba7SYu-cheng Yu unsigned int offset, size; 120591c3dba7SYu-cheng Yu int i; 1206af2c4322SEric Biggers struct xstate_header hdr; 120791c3dba7SYu-cheng Yu 120891c3dba7SYu-cheng Yu offset = offsetof(struct xregs_state, header); 1209af2c4322SEric Biggers size = sizeof(hdr); 121091c3dba7SYu-cheng Yu 1211af2c4322SEric Biggers if (__copy_from_user(&hdr, ubuf + offset, size)) 121291c3dba7SYu-cheng Yu return -EFAULT; 121391c3dba7SYu-cheng Yu 121498c0fad9SEric Biggers if (validate_xstate_header(&hdr)) 121591c3dba7SYu-cheng Yu return -EINVAL; 121691c3dba7SYu-cheng Yu 121791c3dba7SYu-cheng Yu for (i = 0; i < XFEATURE_MAX; i++) { 121891c3dba7SYu-cheng Yu u64 mask = ((u64)1 << i); 121991c3dba7SYu-cheng Yu 12203d703477SEric Biggers if (hdr.xfeatures & mask) { 122107baeb04SSebastian Andrzej Siewior void *dst = __raw_xsave_addr(xsave, i); 122291c3dba7SYu-cheng Yu 122391c3dba7SYu-cheng Yu offset = xstate_offsets[i]; 122491c3dba7SYu-cheng Yu size = xstate_sizes[i]; 122591c3dba7SYu-cheng Yu 122691c3dba7SYu-cheng Yu if (__copy_from_user(dst, ubuf + offset, size)) 122791c3dba7SYu-cheng Yu return -EFAULT; 122891c3dba7SYu-cheng Yu } 122991c3dba7SYu-cheng Yu } 123091c3dba7SYu-cheng Yu 12313d703477SEric Biggers if (xfeatures_mxcsr_quirk(hdr.xfeatures)) { 12320852b374SRik van Riel offset = offsetof(struct fxregs_state, mxcsr); 12330852b374SRik van Riel size = MXCSR_AND_FLAGS_SIZE; 12340852b374SRik van Riel if (__copy_from_user(&xsave->i387.mxcsr, ubuf + offset, size)) 12350852b374SRik van Riel return -EFAULT; 12360852b374SRik van Riel } 12370852b374SRik van Riel 123891c3dba7SYu-cheng Yu /* 123991c3dba7SYu-cheng Yu * The state that came in from userspace was user-state only. 124091c3dba7SYu-cheng Yu * Mask all the user states out of 'xfeatures': 124191c3dba7SYu-cheng Yu */ 124291c3dba7SYu-cheng Yu xsave->header.xfeatures &= XFEATURE_MASK_SUPERVISOR; 124391c3dba7SYu-cheng Yu 124491c3dba7SYu-cheng Yu /* 124591c3dba7SYu-cheng Yu * Add back in the features that came in from userspace: 124691c3dba7SYu-cheng Yu */ 12473d703477SEric Biggers xsave->header.xfeatures |= hdr.xfeatures; 124884594296SDave Hansen 124984594296SDave Hansen return 0; 125084594296SDave Hansen } 12510c608dadSAubrey Li 12520c608dadSAubrey Li #ifdef CONFIG_PROC_PID_ARCH_STATUS 12530c608dadSAubrey Li /* 12540c608dadSAubrey Li * Report the amount of time elapsed in millisecond since last AVX512 12550c608dadSAubrey Li * use in the task. 12560c608dadSAubrey Li */ 12570c608dadSAubrey Li static void avx512_status(struct seq_file *m, struct task_struct *task) 12580c608dadSAubrey Li { 12590c608dadSAubrey Li unsigned long timestamp = READ_ONCE(task->thread.fpu.avx512_timestamp); 12600c608dadSAubrey Li long delta; 12610c608dadSAubrey Li 12620c608dadSAubrey Li if (!timestamp) { 12630c608dadSAubrey Li /* 12640c608dadSAubrey Li * Report -1 if no AVX512 usage 12650c608dadSAubrey Li */ 12660c608dadSAubrey Li delta = -1; 12670c608dadSAubrey Li } else { 12680c608dadSAubrey Li delta = (long)(jiffies - timestamp); 12690c608dadSAubrey Li /* 12700c608dadSAubrey Li * Cap to LONG_MAX if time difference > LONG_MAX 12710c608dadSAubrey Li */ 12720c608dadSAubrey Li if (delta < 0) 12730c608dadSAubrey Li delta = LONG_MAX; 12740c608dadSAubrey Li delta = jiffies_to_msecs(delta); 12750c608dadSAubrey Li } 12760c608dadSAubrey Li 12770c608dadSAubrey Li seq_put_decimal_ll(m, "AVX512_elapsed_ms:\t", delta); 12780c608dadSAubrey Li seq_putc(m, '\n'); 12790c608dadSAubrey Li } 12800c608dadSAubrey Li 12810c608dadSAubrey Li /* 12820c608dadSAubrey Li * Report architecture specific information 12830c608dadSAubrey Li */ 12840c608dadSAubrey Li int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns, 12850c608dadSAubrey Li struct pid *pid, struct task_struct *task) 12860c608dadSAubrey Li { 12870c608dadSAubrey Li /* 12880c608dadSAubrey Li * Report AVX512 state if the processor and build option supported. 12890c608dadSAubrey Li */ 12900c608dadSAubrey Li if (cpu_feature_enabled(X86_FEATURE_AVX512F)) 12910c608dadSAubrey Li avx512_status(m, task); 12920c608dadSAubrey Li 12930c608dadSAubrey Li return 0; 12940c608dadSAubrey Li } 12950c608dadSAubrey Li #endif /* CONFIG_PROC_PID_ARCH_STATUS */ 1296