Borislav Petkov (AMD) b35087763a x86/srso: Add a Speculative RAS Overflow mitigation ... Upstream commit: fb3bd914b3 Add a mitigation for the speculative return address stack overflow vulnerability found on AMD processors. The mitigation works by ensuring all RET instructions speculate to a controlled location, similar to how speculation is controlled in the retpoline sequence. To accomplish this, the __x86_return_thunk forces the CPU to mispredict every function return using a 'safe return' sequence. To ensure the safety of this mitigation, the kernel must ensure that the safe return sequence is itself free from attacker interference. In Zen3 and Zen4, this is accomplished by creating a BTB alias between the untraining function srso_untrain_ret_alias() and the safe return function srso_safe_ret_alias() which results in evicting a potentially poisoned BTB entry and using that safe one for all function returns. In older Zen1 and Zen2, this is accomplished using a reinterpretation technique similar to Retbleed one: srso_untrain_ret() and srso_safe_ret(). Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-08-08 19:58:34 +02:00
..
core-scheduling.rst	admin-guide/hw-vuln: Rephrase a section of core-scheduling.rst	2021-07-25 14:39:17 -06:00
cross-thread-rsb.rst	Documentation/hw-vuln: Add documentation for Cross-Thread Return Predictions	2023-02-14 19:18:05 +01:00
gather_data_sampling.rst	Documentation/x86: Fix backwards on/off logic about YMM support	2023-08-08 19:58:33 +02:00
index.rst	x86/srso: Add a Speculative RAS Overflow mitigation	2023-08-08 19:58:34 +02:00
l1d_flush.rst	Documentation: Add L1D flushing Documentation	2021-07-28 11:42:25 +02:00
l1tf.rst	docs: add IRQ documentation at the core-api book	2020-05-15 12:00:56 -06:00
mds.rst	x86/speculation: Fix incorrect MDS/TAA mitigation status	2019-11-16 13:17:49 +01:00
multihit.rst	x86/bugs/multihit: Fix mitigation reporting when VMX is not in use	2020-08-07 01:32:00 +02:00
processor_mmio_stale_data.rst	x86/bugs: Add "unknown" reporting for MMIO Stale Data	2022-08-31 17:16:47 +02:00
special-register-buffer-data-sampling.rst	docs: admin-guide: hw-vuln: avoid using ReST :doc:foo markup	2021-06-17 13:24:36 -06:00
spectre.rst	Documentation/hw-vuln: Document the interaction between IBRS and STIBP	2023-03-10 09:40:02 +01:00
srso.rst	x86/srso: Add a Speculative RAS Overflow mitigation	2023-08-08 19:58:34 +02:00
tsx_async_abort.rst	Documentation: fix multiple typos found in the admin-guide subdirectory	2020-12-08 10:27:56 -07:00