diff options
Diffstat (limited to '')
-rw-r--r-- | arch/x86/kernel/process.c | 98 |
1 files changed, 60 insertions, 38 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 5d481038fe0b..c21b7347a26d 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -46,6 +46,7 @@ #include <asm/proto.h> #include <asm/frame.h> #include <asm/unwind.h> +#include <asm/tdx.h> #include "process.h" @@ -130,9 +131,11 @@ static int set_new_tls(struct task_struct *p, unsigned long tls) return do_set_thread_area_64(p, ARCH_SET_FS, tls); } -int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, - struct task_struct *p, unsigned long tls) +int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { + unsigned long clone_flags = args->flags; + unsigned long sp = args->stack; + unsigned long tls = args->tls; struct inactive_task_frame *frame; struct fork_frame *fork_frame; struct pt_regs *childregs; @@ -160,6 +163,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, savesegment(ds, p->thread.ds); #else p->thread.sp0 = (unsigned long) (childregs + 1); + savesegment(gs, p->thread.gs); /* * Clear all status flags including IF and set fixed bit. 64bit * does not have this initialization as the frame does not contain @@ -169,13 +173,13 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, frame->flags = X86_EFLAGS_FIXED; #endif - fpu_clone(p, clone_flags); + fpu_clone(p, clone_flags, args->fn); /* Kernel thread ? */ if (unlikely(p->flags & PF_KTHREAD)) { p->thread.pkru = pkru_get_init_value(); memset(childregs, 0, sizeof(struct pt_regs)); - kthread_frame_init(frame, sp, arg); + kthread_frame_init(frame, args->fn, args->fn_arg); return 0; } @@ -191,14 +195,10 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, if (sp) childregs->sp = sp; -#ifdef CONFIG_X86_32 - task_user_gs(p) = get_user_gs(current_pt_regs()); -#endif - - if (unlikely(p->flags & PF_IO_WORKER)) { + if (unlikely(args->fn)) { /* - * An IO thread is a user space thread, but it doesn't - * return to ret_after_fork(). + * A user space thread, but it doesn't return to + * ret_after_fork(). * * In order to indicate that to tools like gdb, * we reset the stack and instruction pointers. @@ -208,7 +208,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, */ childregs->sp = 0; childregs->ip = 0; - kthread_frame_init(frame, sp, arg); + kthread_frame_init(frame, args->fn, args->fn_arg); return 0; } @@ -334,7 +334,7 @@ static int get_cpuid_mode(void) return !test_thread_flag(TIF_NOCPUID); } -static int set_cpuid_mode(struct task_struct *task, unsigned long cpuid_enabled) +static int set_cpuid_mode(unsigned long cpuid_enabled) { if (!boot_cpu_has(X86_FEATURE_CPUID_FAULT)) return -ENODEV; @@ -405,7 +405,7 @@ static void tss_copy_io_bitmap(struct tss_struct *tss, struct io_bitmap *iobm) } /** - * tss_update_io_bitmap - Update I/O bitmap before exiting to usermode + * native_tss_update_io_bitmap - Update I/O bitmap before exiting to user mode */ void native_tss_update_io_bitmap(void) { @@ -600,7 +600,7 @@ static __always_inline void __speculation_ctrl_update(unsigned long tifp, } if (updmsr) - wrmsrl(MSR_IA32_SPEC_CTRL, msr); + write_spec_ctrl_current(msr, false); } static unsigned long speculation_ctrl_update_tif(struct task_struct *tsk) @@ -686,9 +686,6 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p) /* Enforce MSR update to ensure consistent state */ __speculation_ctrl_update(~tifn, tifn); } - - if ((tifp ^ tifn) & _TIF_SLD) - switch_to_sld(tifn); } /* @@ -747,7 +744,7 @@ bool xen_set_default_idle(void) } #endif -void stop_this_cpu(void *dummy) +void __noreturn stop_this_cpu(void *dummy) { local_irq_disable(); /* @@ -765,8 +762,11 @@ void stop_this_cpu(void *dummy) * without the encryption bit, they don't race each other when flushed * and potentially end up with the wrong entry being committed to * memory. + * + * Test the CPUID bit directly because the machine might've cleared + * X86_FEATURE_SME due to cmdline options. */ - if (boot_cpu_has(X86_FEATURE_SME)) + if (cpuid_eax(0x8000001f) & BIT(0)) native_wbinvd(); for (;;) { /* @@ -810,24 +810,43 @@ static void amd_e400_idle(void) } /* - * Intel Core2 and older machines prefer MWAIT over HALT for C1. - * We can't rely on cpuidle installing MWAIT, because it will not load - * on systems that support only C1 -- so the boot default must be MWAIT. - * - * Some AMD machines are the opposite, they depend on using HALT. + * Prefer MWAIT over HALT if MWAIT is supported, MWAIT_CPUID leaf + * exists and whenever MONITOR/MWAIT extensions are present there is at + * least one C1 substate. * - * So for default C1, which is used during boot until cpuidle loads, - * use MWAIT-C1 on Intel HW that has it, else use HALT. + * Do not prefer MWAIT if MONITOR instruction has a bug or idle=nomwait + * is passed to kernel commandline parameter. */ static int prefer_mwait_c1_over_halt(const struct cpuinfo_x86 *c) { - if (c->x86_vendor != X86_VENDOR_INTEL) + u32 eax, ebx, ecx, edx; + + /* User has disallowed the use of MWAIT. Fallback to HALT */ + if (boot_option_idle_override == IDLE_NOMWAIT) return 0; - if (!cpu_has(c, X86_FEATURE_MWAIT) || boot_cpu_has_bug(X86_BUG_MONITOR)) + /* MWAIT is not supported on this platform. Fallback to HALT */ + if (!cpu_has(c, X86_FEATURE_MWAIT)) return 0; - return 1; + /* Monitor has a bug. Fallback to HALT */ + if (boot_cpu_has_bug(X86_BUG_MONITOR)) + return 0; + + cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx); + + /* + * If MWAIT extensions are not available, it is safe to use MWAIT + * with EAX=0, ECX=0. + */ + if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED)) + return 1; + + /* + * If MWAIT extensions are available, there should be at least one + * MWAIT C1 substate present. + */ + return (edx & MWAIT_C1_SUBSTATE_MASK); } /* @@ -870,6 +889,9 @@ void select_idle_routine(const struct cpuinfo_x86 *c) } else if (prefer_mwait_c1_over_halt(c)) { pr_info("using mwait in idle threads\n"); x86_idle = mwait_idle; + } else if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) { + pr_info("using TDX aware idle routine\n"); + x86_idle = tdx_safe_halt; } else x86_idle = default_idle; } @@ -929,9 +951,8 @@ static int __init idle_setup(char *str) } else if (!strcmp(str, "nomwait")) { /* * If the boot option of "idle=nomwait" is added, - * it means that mwait will be disabled for CPU C2/C3 - * states. In such case it won't touch the variable - * of boot_option_idle_override. + * it means that mwait will be disabled for CPU C1/C2/C3 + * states. */ boot_option_idle_override = IDLE_NOMWAIT; } else @@ -944,7 +965,7 @@ early_param("idle", idle_setup); unsigned long arch_align_stack(unsigned long sp) { if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) - sp -= get_random_int() % 8192; + sp -= prandom_u32_max(8192); return sp & ~0xf; } @@ -982,18 +1003,19 @@ unsigned long __get_wchan(struct task_struct *p) return addr; } -long do_arch_prctl_common(struct task_struct *task, int option, - unsigned long arg2) +long do_arch_prctl_common(int option, unsigned long arg2) { switch (option) { case ARCH_GET_CPUID: return get_cpuid_mode(); case ARCH_SET_CPUID: - return set_cpuid_mode(task, arg2); + return set_cpuid_mode(arg2); case ARCH_GET_XCOMP_SUPP: case ARCH_GET_XCOMP_PERM: case ARCH_REQ_XCOMP_PERM: - return fpu_xstate_prctl(task, option, arg2); + case ARCH_GET_XCOMP_GUEST_PERM: + case ARCH_REQ_XCOMP_GUEST_PERM: + return fpu_xstate_prctl(option, arg2); } return -EINVAL; |