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| author | Pawan Gupta <pawan.kumar.gupta@linux.intel.com> | 2025-05-05 14:35:12 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-18 08:20:38 +0200 |
| commit | a1b63a84a789ed550d7910c0b1590322b196a590 (patch) | |
| tree | 69abe72a594afb93f8cd162a2a30d92b85f6f84f /drivers/fpga/fpga-mgr.c | |
| parent | f9340af845a637da9afe9f2dc094641600192981 (diff) | |
x86/bhi: Do not set BHI_DIS_S in 32-bit mode
commit 073fdbe02c69c43fb7c0d547ec265c7747d4a646 upstream.
With the possibility of intra-mode BHI via cBPF, complete mitigation for
BHI is to use IBHF (history fence) instruction with BHI_DIS_S set. Since
this new instruction is only available in 64-bit mode, setting BHI_DIS_S in
32-bit mode is only a partial mitigation.
Do not set BHI_DIS_S in 32-bit mode so as to avoid reporting misleading
mitigated status. With this change IBHF won't be used in 32-bit mode, also
remove the CONFIG_X86_64 check from emit_spectre_bhb_barrier().
Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/fpga/fpga-mgr.c')
0 files changed, 0 insertions, 0 deletions