diff options
Diffstat (limited to 'arch/x86/kernel/fpu')
| -rw-r--r-- | arch/x86/kernel/fpu/bugs.c | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/regset.c | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/signal.c | 22 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 141 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.h | 61 |
6 files changed, 184 insertions, 52 deletions
diff --git a/arch/x86/kernel/fpu/bugs.c b/arch/x86/kernel/fpu/bugs.c index 794e70151203..edbafc5940e3 100644 --- a/arch/x86/kernel/fpu/bugs.c +++ b/arch/x86/kernel/fpu/bugs.c @@ -2,6 +2,9 @@ /* * x86 FPU bug checks: */ +#include <linux/printk.h> + +#include <asm/cpufeature.h> #include <asm/fpu/api.h> /* diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index a21a4d0ecc34..1209c7aebb21 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -145,8 +145,8 @@ void restore_fpregs_from_fpstate(struct fpstate *fpstate, u64 mask) asm volatile( "fnclex\n\t" "emms\n\t" - "fildl %P[addr]" /* set F?P to defined value */ - : : [addr] "m" (fpstate)); + "fildl %[addr]" /* set F?P to defined value */ + : : [addr] "m" (*fpstate)); } if (use_xsave()) { @@ -308,7 +308,7 @@ EXPORT_SYMBOL_GPL(fpu_update_guest_xfd); * Must be invoked from KVM after a VMEXIT before enabling interrupts when * XFD write emulation is disabled. This is required because the guest can * freely modify XFD and the state at VMEXIT is not guaranteed to be the - * same as the state on VMENTER. So software state has to be udpated before + * same as the state on VMENTER. So software state has to be updated before * any operation which depends on it can take place. * * Note: It can be invoked unconditionally even when write emulation is diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c index 6bc1eb2a21bd..887b0b8e21e3 100644 --- a/arch/x86/kernel/fpu/regset.c +++ b/arch/x86/kernel/fpu/regset.c @@ -190,7 +190,8 @@ int ssp_get(struct task_struct *target, const struct user_regset *regset, struct fpu *fpu = &target->thread.fpu; struct cet_user_state *cetregs; - if (!cpu_feature_enabled(X86_FEATURE_USER_SHSTK)) + if (!cpu_feature_enabled(X86_FEATURE_USER_SHSTK) || + !ssp_active(target, regset)) return -ENODEV; sync_fpstate(fpu); diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 558076dbde5b..8f62e0666dea 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -156,10 +156,11 @@ static inline bool save_xstate_epilog(void __user *buf, int ia32_frame, return !err; } -static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf) +static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf, u32 pkru) { if (use_xsave()) - return xsave_to_user_sigframe(buf); + return xsave_to_user_sigframe(buf, pkru); + if (use_fxsr()) return fxsave_to_user_sigframe((struct fxregs_state __user *) buf); else @@ -185,7 +186,7 @@ static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf) * For [f]xsave state, update the SW reserved fields in the [f]xsave frame * indicating the absence/presence of the extended state to the user. */ -bool copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size) +bool copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size, u32 pkru) { struct task_struct *tsk = current; struct fpstate *fpstate = tsk->thread.fpu.fpstate; @@ -228,7 +229,7 @@ retry: fpregs_restore_userregs(); pagefault_disable(); - ret = copy_fpregs_to_sigframe(buf_fx); + ret = copy_fpregs_to_sigframe(buf_fx, pkru); pagefault_enable(); fpregs_unlock(); @@ -274,12 +275,13 @@ static int __restore_fpregs_from_user(void __user *buf, u64 ufeatures, * Attempt to restore the FPU registers directly from user memory. * Pagefaults are handled and any errors returned are fatal. */ -static bool restore_fpregs_from_user(void __user *buf, u64 xrestore, - bool fx_only, unsigned int size) +static bool restore_fpregs_from_user(void __user *buf, u64 xrestore, bool fx_only) { struct fpu *fpu = ¤t->thread.fpu; int ret; + /* Restore enabled features only. */ + xrestore &= fpu->fpstate->user_xfeatures; retry: fpregs_lock(); /* Ensure that XFD is up to date */ @@ -309,7 +311,7 @@ retry: if (ret != X86_TRAP_PF) return false; - if (!fault_in_readable(buf, size)) + if (!fault_in_readable(buf, fpu->fpstate->user_size)) goto retry; return false; } @@ -339,7 +341,6 @@ static bool __fpu_restore_sig(void __user *buf, void __user *buf_fx, struct user_i387_ia32_struct env; bool success, fx_only = false; union fpregs_state *fpregs; - unsigned int state_size; u64 user_xfeatures = 0; if (use_xsave()) { @@ -349,17 +350,14 @@ static bool __fpu_restore_sig(void __user *buf, void __user *buf_fx, return false; fx_only = !fx_sw_user.magic1; - state_size = fx_sw_user.xstate_size; user_xfeatures = fx_sw_user.xfeatures; } else { user_xfeatures = XFEATURE_MASK_FPSSE; - state_size = fpu->fpstate->user_size; } if (likely(!ia32_fxstate)) { /* Restore the FPU registers directly from user memory. */ - return restore_fpregs_from_user(buf_fx, user_xfeatures, fx_only, - state_size); + return restore_fpregs_from_user(buf_fx, user_xfeatures, fx_only); } /* diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 117e74c44e75..27417b685c1d 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -13,16 +13,20 @@ #include <linux/seq_file.h> #include <linux/proc_fs.h> #include <linux/vmalloc.h> +#include <linux/coredump.h> #include <asm/fpu/api.h> #include <asm/fpu/regset.h> #include <asm/fpu/signal.h> #include <asm/fpu/xcr.h> +#include <asm/cpuid.h> #include <asm/tlbflush.h> #include <asm/prctl.h> #include <asm/elf.h> +#include <uapi/asm/elf.h> + #include "context.h" #include "internal.h" #include "legacy.h" @@ -178,10 +182,11 @@ void fpu__init_cpu_xstate(void) * Must happen after CR4 setup and before xsetbv() to allow KVM * lazy passthrough. Write independent of the dynamic state static * key as that does not work on the boot CPU. This also ensures - * that any stale state is wiped out from XFD. + * that any stale state is wiped out from XFD. Reset the per CPU + * xfd cache too. */ if (cpu_feature_enabled(X86_FEATURE_XFD)) - wrmsrl(MSR_IA32_XFD, init_fpstate.xfd); + xfd_set_state(init_fpstate.xfd); /* * XCR_XFEATURE_ENABLED_MASK (aka. XCR0) sets user features @@ -228,7 +233,7 @@ static void __init setup_xstate_cache(void) xmm_space); for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) { - cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx); + cpuid_count(CPUID_LEAF_XSTATE, i, &eax, &ebx, &ecx, &edx); xstate_sizes[i] = eax; xstate_flags[i] = ecx; @@ -394,7 +399,7 @@ int xfeature_size(int xfeature_nr) u32 eax, ebx, ecx, edx; CHECK_XFEATURE(xfeature_nr); - cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); + cpuid_count(CPUID_LEAF_XSTATE, xfeature_nr, &eax, &ebx, &ecx, &edx); return eax; } @@ -437,9 +442,9 @@ static void __init __xstate_dump_leaves(void) * just in case there are some goodies up there */ for (i = 0; i < XFEATURE_MAX + 10; i++) { - cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx); + cpuid_count(CPUID_LEAF_XSTATE, i, &eax, &ebx, &ecx, &edx); pr_warn("CPUID[%02x, %02x]: eax=%08x ebx=%08x ecx=%08x edx=%08x\n", - XSTATE_CPUID, i, eax, ebx, ecx, edx); + CPUID_LEAF_XSTATE, i, eax, ebx, ecx, edx); } } @@ -480,7 +485,7 @@ static int __init check_xtile_data_against_struct(int size) * Check the maximum palette id: * eax: the highest numbered palette subleaf. */ - cpuid_count(TILE_CPUID, 0, &max_palid, &ebx, &ecx, &edx); + cpuid_count(CPUID_LEAF_TILE, 0, &max_palid, &ebx, &ecx, &edx); /* * Cross-check each tile size and find the maximum number of @@ -494,7 +499,7 @@ static int __init check_xtile_data_against_struct(int size) * eax[31:16]: bytes per title * ebx[31:16]: the max names (or max number of tiles) */ - cpuid_count(TILE_CPUID, palid, &eax, &ebx, &edx, &edx); + cpuid_count(CPUID_LEAF_TILE, palid, &eax, &ebx, &edx, &edx); tile_size = eax >> 16; max = ebx >> 16; @@ -629,7 +634,7 @@ static unsigned int __init get_compacted_size(void) * are no supervisor states, but XSAVEC still uses compacted * format. */ - cpuid_count(XSTATE_CPUID, 1, &eax, &ebx, &ecx, &edx); + cpuid_count(CPUID_LEAF_XSTATE, 1, &eax, &ebx, &ecx, &edx); return ebx; } @@ -670,7 +675,7 @@ static unsigned int __init get_xsave_size_user(void) * containing all the *user* state components * corresponding to bits currently set in XCR0. */ - cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx); + cpuid_count(CPUID_LEAF_XSTATE, 0, &eax, &ebx, &ecx, &edx); return ebx; } @@ -759,21 +764,16 @@ void __init fpu__init_system_xstate(unsigned int legacy_size) return; } - if (boot_cpu_data.cpuid_level < XSTATE_CPUID) { - WARN_ON_FPU(1); - return; - } - /* * Find user xstates supported by the processor. */ - cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx); + cpuid_count(CPUID_LEAF_XSTATE, 0, &eax, &ebx, &ecx, &edx); fpu_kernel_cfg.max_features = eax + ((u64)edx << 32); /* * Find supervisor xstates supported by the processor. */ - cpuid_count(XSTATE_CPUID, 1, &eax, &ebx, &ecx, &edx); + cpuid_count(CPUID_LEAF_XSTATE, 1, &eax, &ebx, &ecx, &edx); fpu_kernel_cfg.max_features |= ecx + ((u64)edx << 32); if ((fpu_kernel_cfg.max_features & XFEATURE_MASK_FPSSE) != XFEATURE_MASK_FPSSE) { @@ -787,6 +787,9 @@ void __init fpu__init_system_xstate(unsigned int legacy_size) goto out_disable; } + fpu_kernel_cfg.independent_features = fpu_kernel_cfg.max_features & + XFEATURE_MASK_INDEPENDENT; + /* * Clear XSAVE features that are disabled in the normal CPUID. */ @@ -990,6 +993,20 @@ void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr) return __raw_xsave_addr(xsave, xfeature_nr); } +EXPORT_SYMBOL_GPL(get_xsave_addr); + +/* + * Given an xstate feature nr, calculate where in the xsave buffer the state is. + * The xsave buffer should be in standard format, not compacted (e.g. user mode + * signal frames). + */ +void __user *get_xsave_addr_user(struct xregs_state __user *xsave, int xfeature_nr) +{ + if (WARN_ON_ONCE(!xfeature_enabled(xfeature_nr))) + return NULL; + + return (void __user *)xsave + xstate_offsets[xfeature_nr]; +} #ifdef CONFIG_ARCH_HAS_PKEYS @@ -1433,8 +1450,8 @@ static bool xstate_op_valid(struct fpstate *fpstate, u64 mask, bool rstor) return rstor; /* - * XSAVE(S): clone(), fpu_swap_kvm_fpu() - * XRSTORS(S): fpu_swap_kvm_fpu() + * XSAVE(S): clone(), fpu_swap_kvm_fpstate() + * XRSTORS(S): fpu_swap_kvm_fpstate() */ /* @@ -1836,3 +1853,89 @@ int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns, return 0; } #endif /* CONFIG_PROC_PID_ARCH_STATUS */ + +#ifdef CONFIG_COREDUMP +static const char owner_name[] = "LINUX"; + +/* + * Dump type, size, offset and flag values for every xfeature that is present. + */ +static int dump_xsave_layout_desc(struct coredump_params *cprm) +{ + int num_records = 0; + int i; + + for_each_extended_xfeature(i, fpu_user_cfg.max_features) { + struct x86_xfeat_component xc = { + .type = i, + .size = xstate_sizes[i], + .offset = xstate_offsets[i], + /* reserved for future use */ + .flags = 0, + }; + + if (!dump_emit(cprm, &xc, sizeof(xc))) + return 0; + + num_records++; + } + return num_records; +} + +static u32 get_xsave_desc_size(void) +{ + u32 cnt = 0; + u32 i; + + for_each_extended_xfeature(i, fpu_user_cfg.max_features) + cnt++; + + return cnt * (sizeof(struct x86_xfeat_component)); +} + +int elf_coredump_extra_notes_write(struct coredump_params *cprm) +{ + int num_records = 0; + struct elf_note en; + + if (!fpu_user_cfg.max_features) + return 0; + + en.n_namesz = sizeof(owner_name); + en.n_descsz = get_xsave_desc_size(); + en.n_type = NT_X86_XSAVE_LAYOUT; + + if (!dump_emit(cprm, &en, sizeof(en))) + return 1; + if (!dump_emit(cprm, owner_name, en.n_namesz)) + return 1; + if (!dump_align(cprm, 4)) + return 1; + + num_records = dump_xsave_layout_desc(cprm); + if (!num_records) + return 1; + + /* Total size should be equal to the number of records */ + if ((sizeof(struct x86_xfeat_component) * num_records) != en.n_descsz) + return 1; + + return 0; +} + +int elf_coredump_extra_notes_size(void) +{ + int size; + + if (!fpu_user_cfg.max_features) + return 0; + + /* .note header */ + size = sizeof(struct elf_note); + /* Name plus alignment to 4 bytes */ + size += roundup(sizeof(owner_name), 4); + size += get_xsave_desc_size(); + + return size; +} +#endif /* CONFIG_COREDUMP */ diff --git a/arch/x86/kernel/fpu/xstate.h b/arch/x86/kernel/fpu/xstate.h index 3518fb26d06b..aa16f1a1bbcf 100644 --- a/arch/x86/kernel/fpu/xstate.h +++ b/arch/x86/kernel/fpu/xstate.h @@ -54,7 +54,7 @@ extern int copy_sigframe_from_user_to_xstate(struct task_struct *tsk, const void extern void fpu__init_cpu_xstate(void); extern void fpu__init_system_xstate(unsigned int legacy_size); -extern void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr); +extern void __user *get_xsave_addr_user(struct xregs_state __user *xsave, int xfeature_nr); static inline u64 xfeatures_mask_supervisor(void) { @@ -64,9 +64,31 @@ static inline u64 xfeatures_mask_supervisor(void) static inline u64 xfeatures_mask_independent(void) { if (!cpu_feature_enabled(X86_FEATURE_ARCH_LBR)) - return XFEATURE_MASK_INDEPENDENT & ~XFEATURE_MASK_LBR; + return fpu_kernel_cfg.independent_features & ~XFEATURE_MASK_LBR; - return XFEATURE_MASK_INDEPENDENT; + return fpu_kernel_cfg.independent_features; +} + +/* + * Update the value of PKRU register that was already pushed onto the signal frame. + */ +static inline int update_pkru_in_sigframe(struct xregs_state __user *buf, u64 mask, u32 pkru) +{ + u64 xstate_bv; + int err; + + if (unlikely(!cpu_feature_enabled(X86_FEATURE_OSPKE))) + return 0; + + /* Mark PKRU as in-use so that it is restored correctly. */ + xstate_bv = (mask & xfeatures_in_use()) | XFEATURE_MASK_PKRU; + + err = __put_user(xstate_bv, &buf->header.xfeatures); + if (err) + return err; + + /* Update PKRU value in the userspace xsave buffer. */ + return __put_user(pkru, (unsigned int __user *)get_xsave_addr_user(buf, XFEATURE_PKRU)); } /* XSAVE/XRSTOR wrapper functions */ @@ -108,21 +130,17 @@ static inline u64 xfeatures_mask_independent(void) * Otherwise, if XSAVEOPT is enabled, XSAVEOPT replaces XSAVE because XSAVEOPT * supports modified optimization which is not supported by XSAVE. * - * We use XSAVE as a fallback. - * - * The 661 label is defined in the ALTERNATIVE* macros as the address of the - * original instruction which gets replaced. We need to use it here as the - * address of the instruction where we might get an exception at. + * Use XSAVE as a fallback. */ #define XSTATE_XSAVE(st, lmask, hmask, err) \ - asm volatile(ALTERNATIVE_3(XSAVE, \ + asm volatile("1: " ALTERNATIVE_3(XSAVE, \ XSAVEOPT, X86_FEATURE_XSAVEOPT, \ XSAVEC, X86_FEATURE_XSAVEC, \ XSAVES, X86_FEATURE_XSAVES) \ "\n" \ "xor %[err], %[err]\n" \ "3:\n" \ - _ASM_EXTABLE_TYPE_REG(661b, 3b, EX_TYPE_EFAULT_REG, %[err]) \ + _ASM_EXTABLE_TYPE_REG(1b, 3b, EX_TYPE_EFAULT_REG, %[err]) \ : [err] "=r" (err) \ : "D" (st), "m" (*st), "a" (lmask), "d" (hmask) \ : "memory") @@ -132,11 +150,11 @@ static inline u64 xfeatures_mask_independent(void) * XSAVE area format. */ #define XSTATE_XRESTORE(st, lmask, hmask) \ - asm volatile(ALTERNATIVE(XRSTOR, \ + asm volatile("1: " ALTERNATIVE(XRSTOR, \ XRSTORS, X86_FEATURE_XSAVES) \ "\n" \ "3:\n" \ - _ASM_EXTABLE_TYPE(661b, 3b, EX_TYPE_FPU_RESTORE) \ + _ASM_EXTABLE_TYPE(1b, 3b, EX_TYPE_FPU_RESTORE) \ : \ : "D" (st), "m" (*st), "a" (lmask), "d" (hmask) \ : "memory") @@ -148,20 +166,26 @@ static inline void xfd_validate_state(struct fpstate *fpstate, u64 mask, bool rs #endif #ifdef CONFIG_X86_64 +static inline void xfd_set_state(u64 xfd) +{ + wrmsrl(MSR_IA32_XFD, xfd); + __this_cpu_write(xfd_state, xfd); +} + static inline void xfd_update_state(struct fpstate *fpstate) { if (fpu_state_size_dynamic()) { u64 xfd = fpstate->xfd; - if (__this_cpu_read(xfd_state) != xfd) { - wrmsrl(MSR_IA32_XFD, xfd); - __this_cpu_write(xfd_state, xfd); - } + if (__this_cpu_read(xfd_state) != xfd) + xfd_set_state(xfd); } } extern int __xfd_enable_feature(u64 which, struct fpu_guest *guest_fpu); #else +static inline void xfd_set_state(u64 xfd) { } + static inline void xfd_update_state(struct fpstate *fpstate) { } static inline int __xfd_enable_feature(u64 which, struct fpu_guest *guest_fpu) { @@ -254,7 +278,7 @@ static inline u64 xfeatures_need_sigframe_write(void) * The caller has to zero buf::header before calling this because XSAVE* * does not touch the reserved fields in the header. */ -static inline int xsave_to_user_sigframe(struct xregs_state __user *buf) +static inline int xsave_to_user_sigframe(struct xregs_state __user *buf, u32 pkru) { /* * Include the features which are not xsaved/rstored by the kernel @@ -279,6 +303,9 @@ static inline int xsave_to_user_sigframe(struct xregs_state __user *buf) XSTATE_OP(XSAVE, buf, lmask, hmask, err); clac(); + if (!err) + err = update_pkru_in_sigframe(buf, mask, pkru); + return err; } |