* [PATCH Zisslpcfi 0/2] Support for zisslpcfi in opensbi
@ 2022-12-12 3:08 Deepak Gupta
2022-12-12 3:08 ` [PATCH Zisslpcfi 1/2] include: adding support for zsslpcfi encodings Deepak Gupta
` (2 more replies)
0 siblings, 3 replies; 10+ messages in thread
From: Deepak Gupta @ 2022-12-12 3:08 UTC (permalink / raw)
To: opensbi
Zisslpcfi [1] extension extends risc-v architecture to mitigate against
control-flow integrity attacks (ROP/JOP/COP).
Zisslpcfi uses bits (b23-b29) in (m/s/vs) status CSR for enabling cfi in
lesser privileged mode and record cfi state. One such state is expected
landing pad (ELP). If forward cfi is enabled, indirect call/jmp updates
hart's ELP state (1bit) to true. ELP state is cleared only by a landing
pad instruction else trap is delivered with ELP state recorded in sstatus
CSR.
This two patch series adds following changes to opensbi
- Adds support in opensbi to detect zisslpcfi
- trap redirection updates ELP state accordingly
[1] - https://github.com/riscv/riscv-cfi
Deepak Gupta (2):
include: adding support for zsslpcfi encodings
lib: sbi: zsslpcfi detection and elp cfi state reflect back in status
include/sbi/riscv_encoding.h | 6 ++++++
include/sbi/sbi_hart.h | 2 ++
lib/sbi/sbi_hart.c | 21 +++++++++++++++++++++
lib/sbi/sbi_trap.c | 18 ++++++++++++++++++
4 files changed, 47 insertions(+)
--
2.25.1
^ permalink raw reply [flat|nested] 10+ messages in thread* [PATCH Zisslpcfi 1/2] include: adding support for zsslpcfi encodings 2022-12-12 3:08 [PATCH Zisslpcfi 0/2] Support for zisslpcfi in opensbi Deepak Gupta @ 2022-12-12 3:08 ` Deepak Gupta 2022-12-21 13:39 ` Bin Meng 2022-12-12 3:08 ` [PATCH Zisslpcfi 2/2] lib: sbi: zsslpcfi detection and elp cfi state reflect back in status Deepak Gupta 2022-12-12 5:33 ` [PATCH Zisslpcfi 0/2] Support for zisslpcfi in opensbi Deepak Gupta 2 siblings, 1 reply; 10+ messages in thread From: Deepak Gupta @ 2022-12-12 3:08 UTC (permalink / raw) To: opensbi zsslpcfi extension (see links) introduces b60 (CFI) in menvcfg CSR to enable shadow stack and landing pad for machine and lesser privileged modes. Additionally extension introduces new bits in xstatus for cfi state. Links:https://github.com/riscv/riscv-cfi Signed-off-by: Deepak Gupta <debug@rivosinc.com> --- include/sbi/riscv_encoding.h | 4 ++++ include/sbi/sbi_hart.h | 2 ++ 2 files changed, 6 insertions(+) diff --git a/include/sbi/riscv_encoding.h b/include/sbi/riscv_encoding.h index b0f08c8..1fb520f 100644 --- a/include/sbi/riscv_encoding.h +++ b/include/sbi/riscv_encoding.h @@ -210,9 +210,11 @@ #if __riscv_xlen > 32 #define ENVCFG_STCE (_ULL(1) << 63) #define ENVCFG_PBMTE (_ULL(1) << 62) +#define ENVCFG_CFI (_ULL(1) << 60) #else #define ENVCFGH_STCE (_UL(1) << 31) #define ENVCFGH_PBMTE (_UL(1) << 30) +#define ENVCFGH_CFI (_UL(1) << 28) #endif #define ENVCFG_CBZE (_UL(1) << 7) #define ENVCFG_CBCFE (_UL(1) << 6) @@ -229,6 +231,8 @@ #define CSR_USTATUS 0x000 #define CSR_UIE 0x004 #define CSR_UTVEC 0x005 +#define CSR_LPLR 0x006 +#define CSR_SSP 0x020 /* User Trap Handling (N-extension) */ #define CSR_USCRATCH 0x040 diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h index 95b40e7..d25227d 100644 --- a/include/sbi/sbi_hart.h +++ b/include/sbi/sbi_hart.h @@ -36,6 +36,8 @@ enum sbi_hart_extensions { SBI_HART_EXT_SMSTATEEN, /** HART has Sstc extension */ SBI_HART_EXT_SSTC, + /** HART has sslpcfi extension */ + SBI_HART_EXT_SSLPCFI, /** Maximum index of Hart extension */ SBI_HART_EXT_MAX, -- 2.25.1 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH Zisslpcfi 1/2] include: adding support for zsslpcfi encodings 2022-12-12 3:08 ` [PATCH Zisslpcfi 1/2] include: adding support for zsslpcfi encodings Deepak Gupta @ 2022-12-21 13:39 ` Bin Meng 0 siblings, 0 replies; 10+ messages in thread From: Bin Meng @ 2022-12-21 13:39 UTC (permalink / raw) To: opensbi On Mon, Dec 12, 2022 at 11:10 AM Deepak Gupta <debug@rivosinc.com> wrote: > > zsslpcfi extension (see links) introduces b60 (CFI) in menvcfg CSR to The extension name is Zisslpcfi (capital Z) > enable shadow stack and landing pad for machine and lesser privileged > modes. Additionally extension introduces new bits in xstatus for cfi > state. > > Links:https://github.com/riscv/riscv-cfi nits: need a space after : s/Links/Link > > Signed-off-by: Deepak Gupta <debug@rivosinc.com> > --- > include/sbi/riscv_encoding.h | 4 ++++ > include/sbi/sbi_hart.h | 2 ++ > 2 files changed, 6 insertions(+) > > diff --git a/include/sbi/riscv_encoding.h b/include/sbi/riscv_encoding.h > index b0f08c8..1fb520f 100644 > --- a/include/sbi/riscv_encoding.h > +++ b/include/sbi/riscv_encoding.h > @@ -210,9 +210,11 @@ > #if __riscv_xlen > 32 > #define ENVCFG_STCE (_ULL(1) << 63) > #define ENVCFG_PBMTE (_ULL(1) << 62) > +#define ENVCFG_CFI (_ULL(1) << 60) > #else > #define ENVCFGH_STCE (_UL(1) << 31) > #define ENVCFGH_PBMTE (_UL(1) << 30) > +#define ENVCFGH_CFI (_UL(1) << 28) > #endif > #define ENVCFG_CBZE (_UL(1) << 7) > #define ENVCFG_CBCFE (_UL(1) << 6) > @@ -229,6 +231,8 @@ > #define CSR_USTATUS 0x000 > #define CSR_UIE 0x004 > #define CSR_UTVEC 0x005 > +#define CSR_LPLR 0x006 > +#define CSR_SSP 0x020 > > /* User Trap Handling (N-extension) */ > #define CSR_USCRATCH 0x040 > diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h > index 95b40e7..d25227d 100644 > --- a/include/sbi/sbi_hart.h > +++ b/include/sbi/sbi_hart.h > @@ -36,6 +36,8 @@ enum sbi_hart_extensions { > SBI_HART_EXT_SMSTATEEN, > /** HART has Sstc extension */ > SBI_HART_EXT_SSTC, > + /** HART has sslpcfi extension */ Zisslpcfi > + SBI_HART_EXT_SSLPCFI, SBI_HART_EXT_ZISSLPCFI > > /** Maximum index of Hart extension */ > SBI_HART_EXT_MAX, > -- Regards, Bin ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH Zisslpcfi 2/2] lib: sbi: zsslpcfi detection and elp cfi state reflect back in status 2022-12-12 3:08 [PATCH Zisslpcfi 0/2] Support for zisslpcfi in opensbi Deepak Gupta 2022-12-12 3:08 ` [PATCH Zisslpcfi 1/2] include: adding support for zsslpcfi encodings Deepak Gupta @ 2022-12-12 3:08 ` Deepak Gupta 2022-12-21 13:43 ` Bin Meng 2022-12-12 5:33 ` [PATCH Zisslpcfi 0/2] Support for zisslpcfi in opensbi Deepak Gupta 2 siblings, 1 reply; 10+ messages in thread From: Deepak Gupta @ 2022-12-12 3:08 UTC (permalink / raw) To: opensbi This patch adds support for zsslpcfi detection in sbi_hart.c If zsslpcfi is detected, this turns on menvcfg.CFI zsslpcfi records status of cfi state in xstatus csr. Missing landing pad sets MPELP in mstatus. When SBI is redirecting back to S/VS/HS, SPELP is set in sstatus/vsstatus. Signed-off-by: Deepak Gupta <debug@rivosinc.com> --- include/sbi/riscv_encoding.h | 2 ++ lib/sbi/sbi_hart.c | 21 +++++++++++++++++++++ lib/sbi/sbi_trap.c | 18 ++++++++++++++++++ 3 files changed, 41 insertions(+) diff --git a/include/sbi/riscv_encoding.h b/include/sbi/riscv_encoding.h index 1fb520f..d7886e7 100644 --- a/include/sbi/riscv_encoding.h +++ b/include/sbi/riscv_encoding.h @@ -32,6 +32,8 @@ #define MSTATUS_TVM _UL(0x00100000) #define MSTATUS_TW _UL(0x00200000) #define MSTATUS_TSR _UL(0x00400000) +#define MSTATUS_SPELP _UL(0x10000000) +#define MSTATUS_MPELP _UL(0x20000000) #define MSTATUS32_SD _UL(0x80000000) #if __riscv_xlen == 64 #define MSTATUS_UXL _ULL(0x0000000300000000) diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c index 5447c52..6beae2d 100644 --- a/lib/sbi/sbi_hart.c +++ b/lib/sbi/sbi_hart.c @@ -157,6 +157,16 @@ static void mstatus_init(struct sbi_scratch *scratch) #endif } + if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SSLPCFI)) { +#if __riscv_xlen == 32 + unsigned long menvcfgh_val; + menvcfgh_val = csr_read(CSR_MENVCFGH); + menvcfgh_val |= ENVCFGH_CFI; + csr_write(CSR_MENVCFGH, menvcfgh_val); +#else + menvcfg_val |= ENVCFG_CFI; +#endif + } csr_write(CSR_MENVCFG, menvcfg_val); } @@ -555,6 +565,7 @@ static int hart_detect_features(struct sbi_scratch *scratch) sbi_scratch_offset_ptr(scratch, hart_features_offset); unsigned long val, oldval; int rc; + int ssp_exist, lplr_exist; /* If hart features already detected then do nothing */ if (hfeatures->detected) @@ -693,6 +704,16 @@ __mhpm_skip: SBI_HART_EXT_SMSTATEEN, true); } + if (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_12) { + val = csr_read_allowed(CSR_SSP, (unsigned long)&trap); + ssp_exist = trap.cause?0:1; + val = csr_read_allowed(CSR_LPLR, (unsigned long)&trap); + lplr_exist = trap.cause?0:1; + if (lplr_exist & ssp_exist) + __sbi_hart_update_extension(hfeatures, + SBI_HART_EXT_SSLPCFI, true); + } + /* Let platform populate extensions */ rc = sbi_platform_extensions_init(sbi_platform_thishart_ptr(), hfeatures); diff --git a/lib/sbi/sbi_trap.c b/lib/sbi/sbi_trap.c index c875c90..a700041 100644 --- a/lib/sbi/sbi_trap.c +++ b/lib/sbi/sbi_trap.c @@ -87,6 +87,7 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, struct sbi_trap_info *trap) { ulong hstatus, vsstatus, prev_mode; + bool elp = FALSE; #if __riscv_xlen == 32 bool prev_virt = (regs->mstatusH & MSTATUSH_MPV) ? TRUE : FALSE; #else @@ -100,6 +101,13 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, if (prev_mode != PRV_S && prev_mode != PRV_U) return SBI_ENOTSUPP; + /* If extension has support for CFI, clear MPELP because redirecting to VS or (H)S */ + if (sbi_hart_has_extension(sbi_scratch_thishart_ptr(), SBI_HART_EXT_SSLPCFI)) { + elp = (regs->mstatus & MSTATUS_MPELP)? TRUE: FALSE; + /* Since redirecting, clear mpelp unconditionally */ + regs->mstatus &= ~MSTATUS_MPELP; + } + /* If exceptions came from VS/VU-mode, redirect to VS-mode if * delegated in hedeleg */ @@ -153,6 +161,11 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, /* Get VS-mode SSTATUS CSR */ vsstatus = csr_read(CSR_VSSTATUS); + /*if elp was set, set it back in vsstatus */ + if (elp) { + vsstatus |= MSTATUS_SPELP; + } + /* Set SPP for VS-mode */ vsstatus &= ~SSTATUS_SPP; if (prev_mode == PRV_S) @@ -193,6 +206,11 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, /* Clear SIE for S-mode */ regs->mstatus &= ~MSTATUS_SIE; + + /* if elp was set, set it back in mstatus */ + if (elp) { + regs->mstatus |= MSTATUS_SPELP; + } } return 0; -- 2.25.1 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH Zisslpcfi 2/2] lib: sbi: zsslpcfi detection and elp cfi state reflect back in status 2022-12-12 3:08 ` [PATCH Zisslpcfi 2/2] lib: sbi: zsslpcfi detection and elp cfi state reflect back in status Deepak Gupta @ 2022-12-21 13:43 ` Bin Meng 2022-12-21 13:59 ` Andreas Schwab 2022-12-21 18:41 ` Deepak Gupta 0 siblings, 2 replies; 10+ messages in thread From: Bin Meng @ 2022-12-21 13:43 UTC (permalink / raw) To: opensbi On Mon, Dec 12, 2022 at 11:10 AM Deepak Gupta <debug@rivosinc.com> wrote: > > This patch adds support for zsslpcfi detection in sbi_hart.c > If zsslpcfi is detected, this turns on menvcfg.CFI > > zsslpcfi records status of cfi state in xstatus csr. Missing landing pad > sets MPELP in mstatus. When SBI is redirecting back to S/VS/HS, SPELP is > set in sstatus/vsstatus. > > Signed-off-by: Deepak Gupta <debug@rivosinc.com> > --- > include/sbi/riscv_encoding.h | 2 ++ > lib/sbi/sbi_hart.c | 21 +++++++++++++++++++++ > lib/sbi/sbi_trap.c | 18 ++++++++++++++++++ > 3 files changed, 41 insertions(+) > > diff --git a/include/sbi/riscv_encoding.h b/include/sbi/riscv_encoding.h > index 1fb520f..d7886e7 100644 > --- a/include/sbi/riscv_encoding.h > +++ b/include/sbi/riscv_encoding.h > @@ -32,6 +32,8 @@ > #define MSTATUS_TVM _UL(0x00100000) > #define MSTATUS_TW _UL(0x00200000) > #define MSTATUS_TSR _UL(0x00400000) > +#define MSTATUS_SPELP _UL(0x10000000) > +#define MSTATUS_MPELP _UL(0x20000000) > #define MSTATUS32_SD _UL(0x80000000) > #if __riscv_xlen == 64 > #define MSTATUS_UXL _ULL(0x0000000300000000) > diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c > index 5447c52..6beae2d 100644 > --- a/lib/sbi/sbi_hart.c > +++ b/lib/sbi/sbi_hart.c > @@ -157,6 +157,16 @@ static void mstatus_init(struct sbi_scratch *scratch) > #endif > } > > + if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SSLPCFI)) { > +#if __riscv_xlen == 32 > + unsigned long menvcfgh_val; > + menvcfgh_val = csr_read(CSR_MENVCFGH); > + menvcfgh_val |= ENVCFGH_CFI; > + csr_write(CSR_MENVCFGH, menvcfgh_val); > +#else > + menvcfg_val |= ENVCFG_CFI; > +#endif > + } > csr_write(CSR_MENVCFG, menvcfg_val); > } > > @@ -555,6 +565,7 @@ static int hart_detect_features(struct sbi_scratch *scratch) > sbi_scratch_offset_ptr(scratch, hart_features_offset); > unsigned long val, oldval; > int rc; > + int ssp_exist, lplr_exist; Use bool > > /* If hart features already detected then do nothing */ > if (hfeatures->detected) > @@ -693,6 +704,16 @@ __mhpm_skip: > SBI_HART_EXT_SMSTATEEN, true); > } > > + if (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_12) { > + val = csr_read_allowed(CSR_SSP, (unsigned long)&trap); > + ssp_exist = trap.cause?0:1; need space around ? and : use true/false instead of 1/0 > + val = csr_read_allowed(CSR_LPLR, (unsigned long)&trap); > + lplr_exist = trap.cause?0:1; > + if (lplr_exist & ssp_exist) > + __sbi_hart_update_extension(hfeatures, > + SBI_HART_EXT_SSLPCFI, true); > + } > + > /* Let platform populate extensions */ > rc = sbi_platform_extensions_init(sbi_platform_thishart_ptr(), > hfeatures); > diff --git a/lib/sbi/sbi_trap.c b/lib/sbi/sbi_trap.c > index c875c90..a700041 100644 > --- a/lib/sbi/sbi_trap.c > +++ b/lib/sbi/sbi_trap.c > @@ -87,6 +87,7 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, > struct sbi_trap_info *trap) > { > ulong hstatus, vsstatus, prev_mode; > + bool elp = FALSE; s/FALSE/false > #if __riscv_xlen == 32 > bool prev_virt = (regs->mstatusH & MSTATUSH_MPV) ? TRUE : FALSE; > #else > @@ -100,6 +101,13 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, > if (prev_mode != PRV_S && prev_mode != PRV_U) > return SBI_ENOTSUPP; > > + /* If extension has support for CFI, clear MPELP because redirecting to VS or (H)S */ > + if (sbi_hart_has_extension(sbi_scratch_thishart_ptr(), SBI_HART_EXT_SSLPCFI)) { > + elp = (regs->mstatus & MSTATUS_MPELP)? TRUE: FALSE; > + /* Since redirecting, clear mpelp unconditionally */ > + regs->mstatus &= ~MSTATUS_MPELP; > + } > + > /* If exceptions came from VS/VU-mode, redirect to VS-mode if > * delegated in hedeleg > */ > @@ -153,6 +161,11 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, > /* Get VS-mode SSTATUS CSR */ > vsstatus = csr_read(CSR_VSSTATUS); > > + /*if elp was set, set it back in vsstatus */ need space after /* > + if (elp) { > + vsstatus |= MSTATUS_SPELP; > + } > + > /* Set SPP for VS-mode */ > vsstatus &= ~SSTATUS_SPP; > if (prev_mode == PRV_S) > @@ -193,6 +206,11 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, > > /* Clear SIE for S-mode */ > regs->mstatus &= ~MSTATUS_SIE; > + > + /* if elp was set, set it back in mstatus */ > + if (elp) { > + regs->mstatus |= MSTATUS_SPELP; > + } > } > Regards, Bin ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH Zisslpcfi 2/2] lib: sbi: zsslpcfi detection and elp cfi state reflect back in status 2022-12-21 13:43 ` Bin Meng @ 2022-12-21 13:59 ` Andreas Schwab 2022-12-21 20:01 ` Deepak Gupta 2022-12-21 18:41 ` Deepak Gupta 1 sibling, 1 reply; 10+ messages in thread From: Andreas Schwab @ 2022-12-21 13:59 UTC (permalink / raw) To: opensbi On Dez 21 2022, Bin Meng wrote: >> @@ -693,6 +704,16 @@ __mhpm_skip: >> SBI_HART_EXT_SMSTATEEN, true); >> } >> >> + if (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_12) { >> + val = csr_read_allowed(CSR_SSP, (unsigned long)&trap); >> + ssp_exist = trap.cause?0:1; ssp_exist = trap.cause == 0; -- Andreas Schwab, SUSE Labs, schwab at suse.de GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 "And now for something completely different." ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH Zisslpcfi 2/2] lib: sbi: zsslpcfi detection and elp cfi state reflect back in status 2022-12-21 13:59 ` Andreas Schwab @ 2022-12-21 20:01 ` Deepak Gupta 0 siblings, 0 replies; 10+ messages in thread From: Deepak Gupta @ 2022-12-21 20:01 UTC (permalink / raw) To: opensbi Thanks Andreas and Bin for your review comments. Sent out v2 version of the patch. -Deepak On Wed, Dec 21, 2022 at 5:59 AM Andreas Schwab <schwab@suse.de> wrote: > > On Dez 21 2022, Bin Meng wrote: > > >> @@ -693,6 +704,16 @@ __mhpm_skip: > >> SBI_HART_EXT_SMSTATEEN, true); > >> } > >> > >> + if (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_12) { > >> + val = csr_read_allowed(CSR_SSP, (unsigned long)&trap); > >> + ssp_exist = trap.cause?0:1; > > ssp_exist = trap.cause == 0; > > -- > Andreas Schwab, SUSE Labs, schwab at suse.de > GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 > "And now for something completely different." ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH Zisslpcfi 2/2] lib: sbi: zsslpcfi detection and elp cfi state reflect back in status 2022-12-21 13:43 ` Bin Meng 2022-12-21 13:59 ` Andreas Schwab @ 2022-12-21 18:41 ` Deepak Gupta 2022-12-22 1:29 ` Bin Meng 1 sibling, 1 reply; 10+ messages in thread From: Deepak Gupta @ 2022-12-21 18:41 UTC (permalink / raw) To: opensbi On Wed, Dec 21, 2022 at 5:43 AM Bin Meng <bmeng.cn@gmail.com> wrote: > > > @@ -87,6 +87,7 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, > > struct sbi_trap_info *trap) > > { > > ulong hstatus, vsstatus, prev_mode; > > + bool elp = FALSE; > > s/FALSE/false I followed whatever rest of the code is following. In the same function " int sbi_trap_redirect(struct sbi_trap_regs *regs, struct sbi_trap_info *trap) { ulong hstatus, vsstatus, prev_mode; bool elp = FALSE; #if __riscv_xlen == 32 bool prev_virt = (regs->mstatusH & MSTATUSH_MPV) ? TRUE : FALSE; #else bool prev_virt = (regs->mstatus & MSTATUS_MPV) ? TRUE : FALSE; #endif /* By default, we redirect to HS-mode */ bool next_virt = FALSE; " I can change it to false but it'll look ugly because at other places we're using upper case FALSE. Let me know what needs to be done. > > > #if __riscv_xlen == 32 > > bool prev_virt = (regs->mstatusH & MSTATUSH_MPV) ? TRUE : FALSE; > > #else > > @@ -100,6 +101,13 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, > > if (prev_mode != PRV_S && prev_mode != PRV_U) > > return SBI_ENOTSUPP; > > > > + /* If extension has support for CFI, clear MPELP because redirecting to VS or (H)S */ > > + if (sbi_hart_has_extension(sbi_scratch_thishart_ptr(), SBI_HART_EXT_SSLPCFI)) { > > + elp = (regs->mstatus & MSTATUS_MPELP)? TRUE: FALSE; > > + /* Since redirecting, clear mpelp unconditionally */ > > + regs->mstatus &= ~MSTATUS_MPELP; > > + } > > + > > /* If exceptions came from VS/VU-mode, redirect to VS-mode if > > * delegated in hedeleg > > */ > > @@ -153,6 +161,11 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, > > /* Get VS-mode SSTATUS CSR */ > > vsstatus = csr_read(CSR_VSSTATUS); > > > > + /*if elp was set, set it back in vsstatus */ > > need space after /* > > > + if (elp) { > > + vsstatus |= MSTATUS_SPELP; > > + } > > + > > /* Set SPP for VS-mode */ > > vsstatus &= ~SSTATUS_SPP; > > if (prev_mode == PRV_S) > > @@ -193,6 +206,11 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, > > > > /* Clear SIE for S-mode */ > > regs->mstatus &= ~MSTATUS_SIE; > > + > > + /* if elp was set, set it back in mstatus */ > > + if (elp) { > > + regs->mstatus |= MSTATUS_SPELP; > > + } > > } > > > > Regards, > Bin ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH Zisslpcfi 2/2] lib: sbi: zsslpcfi detection and elp cfi state reflect back in status 2022-12-21 18:41 ` Deepak Gupta @ 2022-12-22 1:29 ` Bin Meng 0 siblings, 0 replies; 10+ messages in thread From: Bin Meng @ 2022-12-22 1:29 UTC (permalink / raw) To: opensbi On Thu, Dec 22, 2022 at 2:41 AM Deepak Gupta <debug@rivosinc.com> wrote: > > On Wed, Dec 21, 2022 at 5:43 AM Bin Meng <bmeng.cn@gmail.com> wrote: > > > > > @@ -87,6 +87,7 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, > > > struct sbi_trap_info *trap) > > > { > > > ulong hstatus, vsstatus, prev_mode; > > > + bool elp = FALSE; > > > > s/FALSE/false > > I followed whatever rest of the code is following. In the same function > > " > int sbi_trap_redirect(struct sbi_trap_regs *regs, > struct sbi_trap_info *trap) > { > ulong hstatus, vsstatus, prev_mode; > bool elp = FALSE; > #if __riscv_xlen == 32 > bool prev_virt = (regs->mstatusH & MSTATUSH_MPV) ? TRUE : FALSE; > #else > bool prev_virt = (regs->mstatus & MSTATUS_MPV) ? TRUE : FALSE; > #endif > /* By default, we redirect to HS-mode */ > bool next_virt = FALSE; > " > I can change it to false but it'll look ugly because at other places > we're using upper case FALSE. > Let me know what needs to be done. > No need to worry about other places, as I already sent one patch to change all other places. Regards, Bin ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH Zisslpcfi 0/2] Support for zisslpcfi in opensbi 2022-12-12 3:08 [PATCH Zisslpcfi 0/2] Support for zisslpcfi in opensbi Deepak Gupta 2022-12-12 3:08 ` [PATCH Zisslpcfi 1/2] include: adding support for zsslpcfi encodings Deepak Gupta 2022-12-12 3:08 ` [PATCH Zisslpcfi 2/2] lib: sbi: zsslpcfi detection and elp cfi state reflect back in status Deepak Gupta @ 2022-12-12 5:33 ` Deepak Gupta 2 siblings, 0 replies; 10+ messages in thread From: Deepak Gupta @ 2022-12-12 5:33 UTC (permalink / raw) To: opensbi I forgot to include URLs to qemu and linux implementation of Zisslpcfi This is where I am maintaining qemu implementation https://github.com/deepak0414/qemu/tree/gh_Zisslpcfi-0.1 And kernel implementation here https://github.com/deepak0414/linux-riscv-cfi/tree/Zisslpcfi-0.1_v6.1-rc2 On Sun, Dec 11, 2022 at 07:08:02PM -0800, Deepak Gupta wrote: >Zisslpcfi [1] extension extends risc-v architecture to mitigate against >control-flow integrity attacks (ROP/JOP/COP). > >Zisslpcfi uses bits (b23-b29) in (m/s/vs) status CSR for enabling cfi in >lesser privileged mode and record cfi state. One such state is expected >landing pad (ELP). If forward cfi is enabled, indirect call/jmp updates >hart's ELP state (1bit) to true. ELP state is cleared only by a landing >pad instruction else trap is delivered with ELP state recorded in sstatus >CSR. > >This two patch series adds following changes to opensbi > - Adds support in opensbi to detect zisslpcfi > - trap redirection updates ELP state accordingly > >[1] - https://github.com/riscv/riscv-cfi > >Deepak Gupta (2): > include: adding support for zsslpcfi encodings > lib: sbi: zsslpcfi detection and elp cfi state reflect back in status > > include/sbi/riscv_encoding.h | 6 ++++++ > include/sbi/sbi_hart.h | 2 ++ > lib/sbi/sbi_hart.c | 21 +++++++++++++++++++++ > lib/sbi/sbi_trap.c | 18 ++++++++++++++++++ > 4 files changed, 47 insertions(+) > >-- >2.25.1 > ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2022-12-22 1:29 UTC | newest] Thread overview: 10+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2022-12-12 3:08 [PATCH Zisslpcfi 0/2] Support for zisslpcfi in opensbi Deepak Gupta 2022-12-12 3:08 ` [PATCH Zisslpcfi 1/2] include: adding support for zsslpcfi encodings Deepak Gupta 2022-12-21 13:39 ` Bin Meng 2022-12-12 3:08 ` [PATCH Zisslpcfi 2/2] lib: sbi: zsslpcfi detection and elp cfi state reflect back in status Deepak Gupta 2022-12-21 13:43 ` Bin Meng 2022-12-21 13:59 ` Andreas Schwab 2022-12-21 20:01 ` Deepak Gupta 2022-12-21 18:41 ` Deepak Gupta 2022-12-22 1:29 ` Bin Meng 2022-12-12 5:33 ` [PATCH Zisslpcfi 0/2] Support for zisslpcfi in opensbi Deepak Gupta
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