Re: [PATCH v8 07/14] x86/cet/ibt: Add ENDBR to op-code-map

[Adrian Hunter]

On 13/08/19 11:53 PM, Yu-cheng Yu wrote:
> Add control transfer terminating instructions:
> 
> ENDBR64/ENDBR32:
>     Mark a valid 64/32-bit control transfer endpoint.
> 
> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
> ---
>  arch/x86/lib/x86-opcode-map.txt               | 13 +++++++++++--
>  tools/objtool/arch/x86/lib/x86-opcode-map.txt | 13 +++++++++++--
>  2 files changed, 22 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/lib/x86-opcode-map.txt b/arch/x86/lib/x86-opcode-map.txt
> index c5e825d44766..fbc53481bc59 100644
> --- a/arch/x86/lib/x86-opcode-map.txt
> +++ b/arch/x86/lib/x86-opcode-map.txt
> @@ -620,7 +620,16 @@ ea: SAVEPREVSSP (f3)
>  # Skip 0xeb-0xff
>  EndTable
>  
> -Table: 3-byte opcode 2 (0x0f 0x38)
> +Table: 3-byte opcode 2 (0x0f 0x1e)
> +Referrer:
> +AVXcode:
> +# Skip 0x00-0xf9
> +fa: ENDBR64 (f3)
> +fb: ENDBR32 (f3)

endbr32 and endbr64 have 2-byte opcodes (0F 1E) and a ModRM byte, so a new
Grp is needed

> +#skip 0xfc-0xff
> +EndTable
> +
> +Table: 3-byte opcode 3 (0x0f 0x38)
>  Referrer: 3-byte escape 1
>  AVXcode: 2
>  # 0x0f 0x38 0x00-0x0f
> @@ -804,7 +813,7 @@ f6: ADCX Gy,Ey (66) | ADOX Gy,Ey (F3) | MULX By,Gy,rDX,Ey (F2),(v) | WRSS Pq,Qq
>  f7: BEXTR Gy,Ey,By (v) | SHLX Gy,Ey,By (66),(v) | SARX Gy,Ey,By (F3),(v) | SHRX Gy,Ey,By (F2),(v)
>  EndTable
>  
> -Table: 3-byte opcode 3 (0x0f 0x3a)
> +Table: 3-byte opcode 4 (0x0f 0x3a)
>  Referrer: 3-byte escape 2
>  AVXcode: 3
>  # 0x0f 0x3a 0x00-0xff
> diff --git a/tools/objtool/arch/x86/lib/x86-opcode-map.txt b/tools/objtool/arch/x86/lib/x86-opcode-map.txt
> index c5e825d44766..fbc53481bc59 100644
> --- a/tools/objtool/arch/x86/lib/x86-opcode-map.txt
> +++ b/tools/objtool/arch/x86/lib/x86-opcode-map.txt
> @@ -620,7 +620,16 @@ ea: SAVEPREVSSP (f3)
>  # Skip 0xeb-0xff
>  EndTable
>  
> -Table: 3-byte opcode 2 (0x0f 0x38)
> +Table: 3-byte opcode 2 (0x0f 0x1e)
> +Referrer:
> +AVXcode:
> +# Skip 0x00-0xf9
> +fa: ENDBR64 (f3)
> +fb: ENDBR32 (f3)
> +#skip 0xfc-0xff
> +EndTable
> +
> +Table: 3-byte opcode 3 (0x0f 0x38)
>  Referrer: 3-byte escape 1
>  AVXcode: 2
>  # 0x0f 0x38 0x00-0x0f
> @@ -804,7 +813,7 @@ f6: ADCX Gy,Ey (66) | ADOX Gy,Ey (F3) | MULX By,Gy,rDX,Ey (F2),(v) | WRSS Pq,Qq
>  f7: BEXTR Gy,Ey,By (v) | SHLX Gy,Ey,By (66),(v) | SARX Gy,Ey,By (F3),(v) | SHRX Gy,Ey,By (F2),(v)
>  EndTable
>  
> -Table: 3-byte opcode 3 (0x0f 0x3a)
> +Table: 3-byte opcode 4 (0x0f 0x3a)
>  Referrer: 3-byte escape 2
>  AVXcode: 3
>  # 0x0f 0x3a 0x00-0xff
>