diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/hw-vuln/spectre.rst | 48 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 12 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/display/msm/qcom,sm8150-mdss.yaml | 9 | ||||
| -rw-r--r-- | Documentation/filesystems/bcachefs/index.rst | 11 | ||||
| -rw-r--r-- | Documentation/filesystems/index.rst | 1 |
5 files changed, 75 insertions, 6 deletions
diff --git a/Documentation/admin-guide/hw-vuln/spectre.rst b/Documentation/admin-guide/hw-vuln/spectre.rst index cce768afec6b..b70b1d8bd8e6 100644 --- a/Documentation/admin-guide/hw-vuln/spectre.rst +++ b/Documentation/admin-guide/hw-vuln/spectre.rst @@ -138,11 +138,10 @@ associated with the source address of the indirect branch. Specifically, the BHB might be shared across privilege levels even in the presence of Enhanced IBRS. -Currently the only known real-world BHB attack vector is via -unprivileged eBPF. Therefore, it's highly recommended to not enable -unprivileged eBPF, especially when eIBRS is used (without retpolines). -For a full mitigation against BHB attacks, it's recommended to use -retpolines (or eIBRS combined with retpolines). +Previously the only known real-world BHB attack vector was via unprivileged +eBPF. Further research has found attacks that don't require unprivileged eBPF. +For a full mitigation against BHB attacks it is recommended to set BHI_DIS_S or +use the BHB clearing sequence. Attack scenarios ---------------- @@ -430,6 +429,23 @@ The possible values in this file are: 'PBRSB-eIBRS: Not affected' CPU is not affected by PBRSB =========================== ======================================================= + - Branch History Injection (BHI) protection status: + +.. list-table:: + + * - BHI: Not affected + - System is not affected + * - BHI: Retpoline + - System is protected by retpoline + * - BHI: BHI_DIS_S + - System is protected by BHI_DIS_S + * - BHI: SW loop; KVM SW loop + - System is protected by software clearing sequence + * - BHI: Syscall hardening + - Syscalls are hardened against BHI + * - BHI: Syscall hardening; KVM: SW loop + - System is protected from userspace attacks by syscall hardening; KVM is protected by software clearing sequence + Full mitigation might require a microcode update from the CPU vendor. When the necessary microcode is not available, the kernel will report vulnerability. @@ -484,7 +500,11 @@ Spectre variant 2 Systems which support enhanced IBRS (eIBRS) enable IBRS protection once at boot, by setting the IBRS bit, and they're automatically protected against - Spectre v2 variant attacks. + some Spectre v2 variant attacks. The BHB can still influence the choice of + indirect branch predictor entry, and although branch predictor entries are + isolated between modes when eIBRS is enabled, the BHB itself is not isolated + between modes. Systems which support BHI_DIS_S will set it to protect against + BHI attacks. On Intel's enhanced IBRS systems, this includes cross-thread branch target injections on SMT systems (STIBP). In other words, Intel eIBRS enables @@ -638,6 +658,22 @@ kernel command line. spectre_v2=off. Spectre variant 1 mitigations cannot be disabled. + spectre_bhi= + + [X86] Control mitigation of Branch History Injection + (BHI) vulnerability. Syscalls are hardened against BHI + regardless of this setting. This setting affects the deployment + of the HW BHI control and the SW BHB clearing sequence. + + on + unconditionally enable. + off + unconditionally disable. + auto + enable if hardware mitigation + control(BHI_DIS_S) is available, otherwise + enable alternate mitigation in KVM. + For spectre_v2_user see Documentation/admin-guide/kernel-parameters.txt Mitigation selection guide diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 623fce7d5fcd..70046a019d42 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6063,6 +6063,18 @@ sonypi.*= [HW] Sony Programmable I/O Control Device driver See Documentation/admin-guide/laptops/sonypi.rst + spectre_bhi= [X86] Control mitigation of Branch History Injection + (BHI) vulnerability. Syscalls are hardened against BHI + reglardless of this setting. This setting affects the + deployment of the HW BHI control and the SW BHB + clearing sequence. + + on - unconditionally enable. + off - unconditionally disable. + auto - (default) enable hardware mitigation + (BHI_DIS_S) if available, otherwise enable + alternate mitigation in KVM. + spectre_v2= [X86,EARLY] Control mitigation of Spectre variant 2 (indirect branch speculation) vulnerability. The default operation protects the kernel from diff --git a/Documentation/devicetree/bindings/display/msm/qcom,sm8150-mdss.yaml b/Documentation/devicetree/bindings/display/msm/qcom,sm8150-mdss.yaml index c0d6a4fdff97..e6dc5494baee 100644 --- a/Documentation/devicetree/bindings/display/msm/qcom,sm8150-mdss.yaml +++ b/Documentation/devicetree/bindings/display/msm/qcom,sm8150-mdss.yaml @@ -53,6 +53,15 @@ patternProperties: compatible: const: qcom,sm8150-dpu + "^displayport-controller@[0-9a-f]+$": + type: object + additionalProperties: true + + properties: + compatible: + contains: + const: qcom,sm8150-dp + "^dsi@[0-9a-f]+$": type: object additionalProperties: true diff --git a/Documentation/filesystems/bcachefs/index.rst b/Documentation/filesystems/bcachefs/index.rst new file mode 100644 index 000000000000..e2bd61ccd96f --- /dev/null +++ b/Documentation/filesystems/bcachefs/index.rst @@ -0,0 +1,11 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====================== +bcachefs Documentation +====================== + +.. toctree:: + :maxdepth: 2 + :numbered: + + errorcodes diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst index 0ea1e44fa028..1f9b4c905a6a 100644 --- a/Documentation/filesystems/index.rst +++ b/Documentation/filesystems/index.rst @@ -69,6 +69,7 @@ Documentation for filesystem implementations. afs autofs autofs-mount-control + bcachefs/index befs bfs btrfs |