diff options
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/rdrand.c | 22 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 22 | ||||
| -rw-r--r-- | arch/x86/kernel/umip.c | 12 |
5 files changed, 44 insertions, 19 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 1167a46e2a30..32acb970f416 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -134,7 +134,7 @@ obj-$(CONFIG_EFI) += sysfb_efi.o obj-$(CONFIG_PERF_EVENTS) += perf_regs.o obj-$(CONFIG_TRACING) += tracepoint.o obj-$(CONFIG_SCHED_MC_PRIO) += itmt.o -obj-$(CONFIG_X86_INTEL_UMIP) += umip.o +obj-$(CONFIG_X86_UMIP) += umip.o obj-$(CONFIG_UNWINDER_ORC) += unwind_orc.o obj-$(CONFIG_UNWINDER_FRAME_POINTER) += unwind_frame.o diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index fffe21945374..3103f2bfed85 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -565,8 +565,9 @@ static const char *table_lookup_model(struct cpuinfo_x86 *c) return NULL; /* Not found */ } -__u32 cpu_caps_cleared[NCAPINTS + NBUGINTS]; -__u32 cpu_caps_set[NCAPINTS + NBUGINTS]; +/* Aligned to unsigned long to avoid split lock in atomic bitmap ops */ +__u32 cpu_caps_cleared[NCAPINTS + NBUGINTS] __aligned(sizeof(unsigned long)); +__u32 cpu_caps_set[NCAPINTS + NBUGINTS] __aligned(sizeof(unsigned long)); void load_percpu_segment(int cpu) { diff --git a/arch/x86/kernel/cpu/rdrand.c b/arch/x86/kernel/cpu/rdrand.c index 5c900f9527ff..c4be62058dd9 100644 --- a/arch/x86/kernel/cpu/rdrand.c +++ b/arch/x86/kernel/cpu/rdrand.c @@ -29,7 +29,8 @@ __setup("nordrand", x86_rdrand_setup); #ifdef CONFIG_ARCH_RANDOM void x86_init_rdrand(struct cpuinfo_x86 *c) { - unsigned long tmp; + unsigned int changed = 0; + unsigned long tmp, prev; int i; if (!cpu_has(c, X86_FEATURE_RDRAND)) @@ -42,5 +43,24 @@ void x86_init_rdrand(struct cpuinfo_x86 *c) return; } } + + /* + * Stupid sanity-check whether RDRAND does *actually* generate + * some at least random-looking data. + */ + prev = tmp; + for (i = 0; i < SANITY_CHECK_LOOPS; i++) { + if (rdrand_long(&tmp)) { + if (prev != tmp) + changed++; + + prev = tmp; + } + } + + if (WARN_ON_ONCE(!changed)) + pr_emerg( +"RDRAND gives funky smelling output, might consider not using it by booting with \"nordrand\""); + } #endif diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index e5cb67d67c03..319be936c348 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -60,7 +60,7 @@ u64 xfeatures_mask __read_mostly; static unsigned int xstate_offsets[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1}; static unsigned int xstate_sizes[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1}; -static unsigned int xstate_comp_offsets[sizeof(xfeatures_mask)*8]; +static unsigned int xstate_comp_offsets[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1}; /* * The XSAVE area of kernel can be in standard or compacted format; @@ -254,10 +254,13 @@ static void __init setup_xstate_features(void) * in the fixed offsets in the xsave area in either compacted form * or standard form. */ - xstate_offsets[0] = 0; - xstate_sizes[0] = offsetof(struct fxregs_state, xmm_space); - xstate_offsets[1] = xstate_sizes[0]; - xstate_sizes[1] = FIELD_SIZEOF(struct fxregs_state, xmm_space); + xstate_offsets[XFEATURE_FP] = 0; + xstate_sizes[XFEATURE_FP] = offsetof(struct fxregs_state, + xmm_space); + + xstate_offsets[XFEATURE_SSE] = xstate_sizes[XFEATURE_FP]; + xstate_sizes[XFEATURE_SSE] = FIELD_SIZEOF(struct fxregs_state, + xmm_space); for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { if (!xfeature_enabled(i)) @@ -342,7 +345,7 @@ static int xfeature_is_aligned(int xfeature_nr) */ static void __init setup_xstate_comp(void) { - unsigned int xstate_comp_sizes[sizeof(xfeatures_mask)*8]; + unsigned int xstate_comp_sizes[XFEATURE_MAX]; int i; /* @@ -350,8 +353,9 @@ static void __init setup_xstate_comp(void) * in the fixed offsets in the xsave area in either compacted form * or standard form. */ - xstate_comp_offsets[0] = 0; - xstate_comp_offsets[1] = offsetof(struct fxregs_state, xmm_space); + xstate_comp_offsets[XFEATURE_FP] = 0; + xstate_comp_offsets[XFEATURE_SSE] = offsetof(struct fxregs_state, + xmm_space); if (!boot_cpu_has(X86_FEATURE_XSAVES)) { for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { @@ -840,7 +844,7 @@ void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr) /* * We should not ever be requesting features that we - * have not enabled. Remember that pcntxt_mask is + * have not enabled. Remember that xfeatures_mask is * what we write to the XCR0 register. */ WARN_ONCE(!(xfeatures_mask & BIT_ULL(xfeature_nr)), diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c index b4a304893189..4d732a444711 100644 --- a/arch/x86/kernel/umip.c +++ b/arch/x86/kernel/umip.c @@ -1,6 +1,6 @@ /* - * umip.c Emulation for instruction protected by the Intel User-Mode - * Instruction Prevention feature + * umip.c Emulation for instruction protected by the User-Mode Instruction + * Prevention feature * * Copyright (c) 2017, Intel Corporation. * Ricardo Neri <ricardo.neri-calderon@linux.intel.com> @@ -18,10 +18,10 @@ /** DOC: Emulation for User-Mode Instruction Prevention (UMIP) * - * The feature User-Mode Instruction Prevention present in recent Intel - * processor prevents a group of instructions (SGDT, SIDT, SLDT, SMSW and STR) - * from being executed with CPL > 0. Otherwise, a general protection fault is - * issued. + * User-Mode Instruction Prevention is a security feature present in recent + * x86 processors that, when enabled, prevents a group of instructions (SGDT, + * SIDT, SLDT, SMSW and STR) from being run in user mode by issuing a general + * protection fault if the instruction is executed with CPL > 0. * * Rather than relaying to the user space the general protection fault caused by * the UMIP-protected instructions (in the form of a SIGSEGV signal), it can be |