x86/insn: Add Control-flow Enforcement (CET) instructions to the opcode map
Add the following CET instructions to the opcode map: INCSSP: Increment Shadow Stack pointer (SSP). RDSSP: Read SSP into a GPR. SAVEPREVSSP: Use "previous ssp" token at top of current Shadow Stack (SHSTK) to create a "restore token" on the previous (outgoing) SHSTK. RSTORSSP: Restore from a "restore token" to SSP. WRSS: Write to kernel-mode SHSTK (kernel-mode instruction). WRUSS: Write to user-mode SHSTK (kernel-mode instruction). SETSSBSY: Verify the "supervisor token" pointed by MSR_IA32_PL0_SSP, set the token busy, and set then Shadow Stack pointer(SSP) to the value of MSR_IA32_PL0_SSP. CLRSSBSY: Verify the "supervisor token" and clear its busy bit. ENDBR64/ENDBR32: Mark a valid 64/32 bit control transfer endpoint. Detailed information of CET instructions can be found in Intel Software Developer's Manual. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lkml.kernel.org/r/20200204171425.28073-2-yu-cheng.yu@intel.com
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