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| author | David Woodhouse <dwmw@amazon.co.uk> | 2018-01-25 16:14:15 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-01-26 15:53:18 +0100 |
| commit | 20ffa1caecca4db8f79fe665acdeaa5af815a24d (patch) | |
| tree | 7c96c70a366d24e44e6b85d84921cd837c3fad76 /arch/x86/kernel | |
| parent | a5b2966364538a0e68c9fa29bc0a3a1651799035 (diff) | |
| download | linux-20ffa1caecca4db8f79fe665acdeaa5af815a24d.tar.gz | |
x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support
Expose indirect_branch_prediction_barrier() for use in subsequent patches. [ tglx: Add IBPB status to spectre_v2 sysfs file ] Co-developed-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Cc: gnomes@lxorguk.ukuu.org.uk Cc: ak@linux.intel.com Cc: ashok.raj@intel.com Cc: dave.hansen@intel.com Cc: arjan@linux.intel.com Cc: torvalds@linux-foundation.org Cc: peterz@infradead.org Cc: bp@alien8.de Cc: pbonzini@redhat.com Cc: tim.c.chen@linux.intel.com Cc: gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/1516896855-7642-8-git-send-email-dwmw@amazon.co.uk
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 4a39d7bb4bd8..bac7a3558db2 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -263,6 +263,13 @@ retpoline_auto: setup_force_cpu_cap(X86_FEATURE_RSB_CTXSW); pr_info("Filling RSB on context switch\n"); } + + /* Initialize Indirect Branch Prediction Barrier if supported */ + if (boot_cpu_has(X86_FEATURE_SPEC_CTRL) || + boot_cpu_has(X86_FEATURE_AMD_PRED_CMD)) { + setup_force_cpu_cap(X86_FEATURE_IBPB); + pr_info("Enabling Indirect Branch Prediction Barrier\n"); + } } #undef pr_fmt @@ -292,7 +299,8 @@ ssize_t cpu_show_spectre_v2(struct device *dev, if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2)) return sprintf(buf, "Not affected\n"); - return sprintf(buf, "%s%s\n", spectre_v2_strings[spectre_v2_enabled], + return sprintf(buf, "%s%s%s\n", spectre_v2_strings[spectre_v2_enabled], + boot_cpu_has(X86_FEATURE_IBPB) ? ", IPBP" : "", spectre_v2_bad_module ? " - vulnerable module loaded" : ""); } #endif |