From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu-cheng Yu Subject: Re: [PATCH v8 27/27] x86/cet/shstk: Add Shadow Stack instructions to opcode map Date: Fri, 08 Nov 2019 10:09:17 -0800 Message-ID: <530c46a1f4be6477ad75803401cfd4ce18abbd95.camel@intel.com> References: <20190813205225.12032-1-yu-cheng.yu@intel.com> <20190813205225.12032-28-yu-cheng.yu@intel.com> <15568c48-b950-484d-d176-0f0e38a94bf7@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <15568c48-b950-484d-d176-0f0e38a94bf7@intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Adrian Hunter , x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz List-Id: linux-api@vger.kernel.org On Fri, 2019-11-08 at 15:27 +0200, Adrian Hunter wrote: > On 13/08/19 11:52 PM, Yu-cheng Yu wrote: > > Add the following shadow stack management instructions. > > > > INCSSP: > > Increment shadow stack pointer by the steps specified. > > > > RDSSP: > > Read SSP register into a GPR. > > > > SAVEPREVSSP: > > Use "prev ssp" token at top of current shadow stack to > > create a "restore token" on previous shadow stack. > > > > RSTORSSP: > > Restore from a "restore token" pointed by a GPR to SSP. > > > > WRSS: > > Write to kernel-mode shadow stack (kernel-mode instruction). > > > > WRUSS: > > Write to user-mode shadow stack (kernel-mode instruction). > > > > SETSSBSY: > > Verify the "supervisor token" pointed by IA32_PL0_SSP MSR, > > if valid, set the token to busy, and set SSP to the value > > of IA32_PL0_SSP MSR. > > > > CLRSSBSY: > > Verify the "supervisor token" pointed by a GPR, if valid, > > clear the busy bit from the token. > > > > Signed-off-by: Yu-cheng Yu > > --- > > arch/x86/lib/x86-opcode-map.txt | 26 +++++++++++++------ > > tools/objtool/arch/x86/lib/x86-opcode-map.txt | 26 +++++++++++++------ > > 2 files changed, 36 insertions(+), 16 deletions(-) > > > > diff --git a/arch/x86/lib/x86-opcode-map.txt b/arch/x86/lib/x86-opcode-map.txt > > index e0b85930dd77..c5e825d44766 100644 > > --- a/arch/x86/lib/x86-opcode-map.txt > > +++ b/arch/x86/lib/x86-opcode-map.txt > > @@ -366,7 +366,7 @@ AVXcode: 1 > > 1b: BNDCN Gv,Ev (F2) | BNDMOV Ev,Gv (66) | BNDMK Gv,Ev (F3) | BNDSTX Ev,Gv > > 1c: > > 1d: > > -1e: 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 > > 2 (0x0f 0x3a)> > +Table: 3-byte opcode 3 (0x0f 0x3a)> > Referrer: 3-byte > > escape 2> > AVXcode: 3> > # 0x0f 0x3a 0x00-0xff> > @@ -948,7 +958,7 @@ > > GrpTable: Grp7> > 2: LGDT Ms | XGETBV (000),(11B) | XSETBV (001),(11B) | > > VMFUNC (100),(11B) | XEND (101)(11B) | XTEST (110)(11B)> > 3: LIDT Ms> > > > 4: SMSW Mw/Rv> > -5: rdpkru (110),(11B) | wrpkru (111),(11B)> > +5: rdpkru > > (110),(11B) | wrpkru (111),(11B) | RSTORSSP Mq (F3)> > 6: LMSW Ew> > 7: > > INVLPG Mb | SWAPGS (o64),(000),(11B) | RDTSCP (001),(11B)> > EndTable> > @@ > > -1019,8 +1029,8 @@ GrpTable: Grp15> > 2: vldmxcsr Md (v1) | WRFSBASE Ry > > (F3),(11B)> > 3: vstmxcsr Md (v1) | WRGSBASE Ry (F3),(11B)> > 4: XSAVE | > > ptwrite Ey (F3),(11B)> > -5: XRSTOR | lfence (11B)> > -6: XSAVEOPT | clwb > > (66) | mfence (11B)> > +5: XRSTOR | lfence (11B) | INCSSP Rd (F3),REX.W> > > > +6: XSAVEOPT | clwb (66) | mfence (11B) | CLRSSBSY Mq (F3)> > 7: clflush | > > clflushopt (66) | sfence (11B)> > EndTable> > > > > > > > > > > > +1e: RDSSP Rd (F3),REX.W > > 1f: NOP Ev > > # 0x0f 0x20-0x2f > > 20: MOV Rd,Cd > > @@ -610,7 +610,17 @@ fe: paddd Pq,Qq | vpaddd Vx,Hx,Wx (66),(v1) > > ff: UD0 > > EndTable > > > > -Table: 3-byte opcode 1 (0x0f 0x38) > > +Table: 3-byte opcode 1 (0x0f 0x01) > > +Referrer: > > +AVXcode: > > +# Skip 0x00-0xe7 > > +e8: SETSSBSY (f3) > > +e9: > > +ea: SAVEPREVSSP (f3) > > +# Skip 0xeb-0xff > > +EndTable > > + > > +Table: 3-byte opcode 2 (0x0f 0x38) > > Referrer: 3-byte escape 1 > > AVXcode: 2 > > # 0x0f 0x38 0x00-0x0f > > @@ -789,12 +799,12 @@ f0: MOVBE Gy,My | MOVBE Gw,Mw (66) | CRC32 Gd,Eb (F2) | CRC32 Gd,Eb (66&F2) > > f1: MOVBE My,Gy | MOVBE Mw,Gw (66) | CRC32 Gd,Ey (F2) | CRC32 Gd,Ew (66&F2) > > f2: ANDN Gy,By,Ey (v) > > f3: Grp17 (1A) > > -f5: BZHI Gy,Ey,By (v) | PEXT Gy,By,Ey (F3),(v) | PDEP Gy,By,Ey (F2),(v) > > -f6: ADCX Gy,Ey (66) | ADOX Gy,Ey (F3) | MULX By,Gy,rDX,Ey (F2),(v) > > +f5: BZHI Gy,Ey,By (v) | PEXT Gy,By,Ey (F3),(v) | PDEP Gy,By,Ey (F2),(v) | WRUSS Pq,Qq (66),REX.W > > +f6: ADCX Gy,Ey (66) | ADOX Gy,Ey (F3) | MULX By,Gy,rDX,Ey (F2),(v) | WRSS Pq,Qq (66),REX.W > > 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 2 (0x0f 0x3a) > > +Table: 3-byte opcode 3 (0x0f 0x3a) > > Referrer: 3-byte escape 2 > > AVXcode: 3 > > # 0x0f 0x3a 0x00-0xff > > @@ -948,7 +958,7 @@ GrpTable: Grp7 > > 2: LGDT Ms | XGETBV (000),(11B) | XSETBV (001),(11B) | VMFUNC (100),(11B) | XEND (101)(11B) | XTEST (110)(11B) > > 3: LIDT Ms > > 4: SMSW Mw/Rv > > -5: rdpkru (110),(11B) | wrpkru (111),(11B) > > +5: rdpkru (110),(11B) | wrpkru (111),(11B) | RSTORSSP Mq (F3) > > 6: LMSW Ew > > 7: INVLPG Mb | SWAPGS (o64),(000),(11B) | RDTSCP (001),(11B) > > EndTable > > @@ -1019,8 +1029,8 @@ GrpTable: Grp15 > > 2: vldmxcsr Md (v1) | WRFSBASE Ry (F3),(11B) > > 3: vstmxcsr Md (v1) | WRGSBASE Ry (F3),(11B) > > 4: XSAVE | ptwrite Ey (F3),(11B) > > -5: XRSTOR | lfence (11B) > > -6: XSAVEOPT | clwb (66) | mfence (11B) > > +5: XRSTOR | lfence (11B) | INCSSP Rd (F3),REX.W > > +6: XSAVEOPT | clwb (66) | mfence (11B) | CLRSSBSY Mq (F3) > > 7: clflush | clflushopt (66) | sfence (11B) > > EndTable > > > > diff --git a/tools/objtool/arch/x86/lib/x86-opcode-map.txt b/tools/objtool/arch/x86/lib/x86-opcode-map.txt > > index e0b85930dd77..c5e825d44766 100644 > > --- a/tools/objtool/arch/x86/lib/x86-opcode-map.txt > > +++ b/tools/objtool/arch/x86/lib/x86-opcode-map.txt > > @@ -366,7 +366,7 @@ AVXcode: 1 > > 1b: BNDCN Gv,Ev (F2) | BNDMOV Ev,Gv (66) | BNDMK Gv,Ev (F3) | BNDSTX Ev,Gv > > 1c: > > 1d: > > -1e: > > +1e: RDSSP Rd (F3),REX.W > > RDSSP is in a Grp with ENDBR32 and ENDBR64 > > > 1f: NOP Ev > > # 0x0f 0x20-0x2f > > 20: MOV Rd,Cd > > @@ -610,7 +610,17 @@ fe: paddd Pq,Qq | vpaddd Vx,Hx,Wx (66),(v1) > > ff: UD0 > > EndTable > > > > -Table: 3-byte opcode 1 (0x0f 0x38) > > +Table: 3-byte opcode 1 (0x0f 0x01) > > +Referrer: > > +AVXcode: > > +# Skip 0x00-0xe7 > > +e8: SETSSBSY (f3) > > +e9: > > +ea: SAVEPREVSSP (f3) > > SETSSBSY and SAVEPREVSSP should be in Grp7 > > > +# Skip 0xeb-0xff > > +EndTable > > + > > +Table: 3-byte opcode 2 (0x0f 0x38) > > Referrer: 3-byte escape 1 > > AVXcode: 2 > > # 0x0f 0x38 0x00-0x0f > > @@ -789,12 +799,12 @@ f0: MOVBE Gy,My | MOVBE Gw,Mw (66) | CRC32 Gd,Eb (F2) | CRC32 Gd,Eb (66&F2) > > f1: MOVBE My,Gy | MOVBE Mw,Gw (66) | CRC32 Gd,Ey (F2) | CRC32 Gd,Ew (66&F2) > > f2: ANDN Gy,By,Ey (v) > > f3: Grp17 (1A) > > -f5: BZHI Gy,Ey,By (v) | PEXT Gy,By,Ey (F3),(v) | PDEP Gy,By,Ey (F2),(v) > > -f6: ADCX Gy,Ey (66) | ADOX Gy,Ey (F3) | MULX By,Gy,rDX,Ey (F2),(v) > > +f5: BZHI Gy,Ey,By (v) | PEXT Gy,By,Ey (F3),(v) | PDEP Gy,By,Ey (F2),(v) | WRUSS Pq,Qq (66),REX.W > > +f6: ADCX Gy,Ey (66) | ADOX Gy,Ey (F3) | MULX By,Gy,rDX,Ey (F2),(v) | WRSS Pq,Qq (66),REX.W > > I know already commented on this, but WRSS does not have (66) prefix > > Also no other instructions have been annotated with REX.W so maybe omit that Thanks! I will look into that. Yu-cheng