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authorJens Axboe <axboe@kernel.dk>2018-02-05 12:55:38 -0700
committerJens Axboe <axboe@kernel.dk>2018-02-05 12:55:38 -0700
commit9e05c864993c5442227f83ae1694a737d7a102ed (patch)
treee35b60bb3c0c179f147e9acaad5444f1e5d9117e /arch/x86/include/asm/barrier.h
parent3c15f3f545afa320c5e3822825a9a53c664776b6 (diff)
parent35277995e17919ab838beae765f440674e8576eb (diff)
Merge branch 'master' into test
* master: (688 commits) dt-bindings: mailbox: qcom: Document the APCS clock binding mailbox: qcom: Create APCS child device for clock controller mailbox: qcom: Convert APCS IPC driver to use regmap KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES KVM/x86: Add IBPB support KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDX pinctrl: remove include file from <linux/device.h> firmware: dmi: handle missing DMI data gracefully firmware: dmi_scan: Fix handling of empty DMI strings firmware: dmi_scan: Drop dmi_initialized firmware: dmi: Optimize dmi_matches Revert "defer call to mem_cgroup_sk_alloc()" soreuseport: fix mem leak in reuseport_add_sock() net: qlge: use memmove instead of skb_copy_to_linear_data net: qed: use correct strncpy() size net: cxgb4: avoid memcpy beyond end of source buffer cls_u32: add missing RCU annotation. r8152: set rx mode early when linking on ...
Diffstat (limited to 'arch/x86/include/asm/barrier.h')
-rw-r--r--arch/x86/include/asm/barrier.h28
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h
index 7fb336210e1b..30d406146016 100644
--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -24,6 +24,34 @@
#define wmb() asm volatile("sfence" ::: "memory")
#endif
+/**
+ * array_index_mask_nospec() - generate a mask that is ~0UL when the
+ * bounds check succeeds and 0 otherwise
+ * @index: array element index
+ * @size: number of elements in array
+ *
+ * Returns:
+ * 0 - (index < size)
+ */
+static inline unsigned long array_index_mask_nospec(unsigned long index,
+ unsigned long size)
+{
+ unsigned long mask;
+
+ asm ("cmp %1,%2; sbb %0,%0;"
+ :"=r" (mask)
+ :"r"(size),"r" (index)
+ :"cc");
+ return mask;
+}
+
+/* Override the default implementation from linux/nospec.h. */
+#define array_index_mask_nospec array_index_mask_nospec
+
+/* Prevent speculative execution past this barrier. */
+#define barrier_nospec() alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC, \
+ "lfence", X86_FEATURE_LFENCE_RDTSC)
+
#ifdef CONFIG_X86_PPRO_FENCE
#define dma_rmb() rmb()
#else