[PATCH v3] [PATCH] powerpc/sstep: Check ISA 3.0 instruction validity before emulation

Subsystems: linux for powerpc (32-bit and 64-bit), the rest

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4 messages, 4 authors, 2021-01-21 · open the first message on its own page

[PATCH v3] [PATCH] powerpc/sstep: Check ISA 3.0 instruction validity before emulation

From: Ananth N Mavinakayanahalli <hidden>
Date: 2021-01-20 11:17:01 

We currently unconditionally try to emulate newer instructions on older
Power versions that could cause issues. Gate it.

Signed-off-by: Ananth N Mavinakayanahalli <redacted>
---

[v3] Addressed Naveen's comments on scv and addpcis
[v2] Fixed description

 arch/powerpc/lib/sstep.c |   46 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index bf7a7d62ae8b..5a425a4a1d88 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -1304,9 +1304,11 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 		if ((word & 0xfe2) == 2)
 			op->type = SYSCALL;
 		else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) &&
-				(word & 0xfe3) == 1)
+				(word & 0xfe3) == 1) {	/* scv */
 			op->type = SYSCALL_VECTORED_0;
-		else
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
+		} else
 			op->type = UNKNOWN;
 		return 0;
 #endif
@@ -1530,6 +1532,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 	case 19:
 		if (((word >> 1) & 0x1f) == 2) {
 			/* addpcis */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			imm = (short) (word & 0xffc1);	/* d0 + d2 fields */
 			imm |= (word >> 15) & 0x3e;	/* d1 field */
 			op->val = regs->nip + (imm << 16) + 4;
@@ -2439,6 +2443,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 268:	/* lxvx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(LOAD_VSX, 0, 16);
 			op->element_size = 16;
@@ -2448,6 +2454,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 		case 269:	/* lxvl */
 		case 301: {	/* lxvll */
 			int nb;
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->ea = ra ? regs->gpr[ra] : 0;
 			nb = regs->gpr[rb] & 0xff;
@@ -2475,6 +2483,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 364:	/* lxvwsx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(LOAD_VSX, 0, 4);
 			op->element_size = 4;
@@ -2482,6 +2492,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 396:	/* stxvx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(STORE_VSX, 0, 16);
 			op->element_size = 16;
@@ -2491,6 +2503,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 		case 397:	/* stxvl */
 		case 429: {	/* stxvll */
 			int nb;
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->ea = ra ? regs->gpr[ra] : 0;
 			nb = regs->gpr[rb] & 0xff;
@@ -2542,6 +2556,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 781:	/* lxsibzx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(LOAD_VSX, 0, 1);
 			op->element_size = 8;
@@ -2549,6 +2565,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 812:	/* lxvh8x */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(LOAD_VSX, 0, 16);
 			op->element_size = 2;
@@ -2556,6 +2574,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 813:	/* lxsihzx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(LOAD_VSX, 0, 2);
 			op->element_size = 8;
@@ -2569,6 +2589,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 876:	/* lxvb16x */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(LOAD_VSX, 0, 16);
 			op->element_size = 1;
@@ -2582,6 +2604,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 909:	/* stxsibx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(STORE_VSX, 0, 1);
 			op->element_size = 8;
@@ -2589,6 +2613,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 940:	/* stxvh8x */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(STORE_VSX, 0, 16);
 			op->element_size = 2;
@@ -2596,6 +2622,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 941:	/* stxsihx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(STORE_VSX, 0, 2);
 			op->element_size = 8;
@@ -2609,6 +2637,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 1004:	/* stxvb16x */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(STORE_VSX, 0, 16);
 			op->element_size = 1;
@@ -2717,12 +2747,16 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			op->type = MKOP(LOAD_FP, 0, 16);
 			break;
 		case 2:		/* lxsd */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd + 32;
 			op->type = MKOP(LOAD_VSX, 0, 8);
 			op->element_size = 8;
 			op->vsx_flags = VSX_CHECK_VEC;
 			break;
 		case 3:		/* lxssp */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd + 32;
 			op->type = MKOP(LOAD_VSX, 0, 4);
 			op->element_size = 8;
@@ -2775,6 +2809,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 1:		/* lxv */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->ea = dqform_ea(word, regs);
 			if (word & 8)
 				op->reg = rd + 32;
@@ -2785,6 +2821,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 
 		case 2:		/* stxsd with LSB of DS field = 0 */
 		case 6:		/* stxsd with LSB of DS field = 1 */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->ea = dsform_ea(word, regs);
 			op->reg = rd + 32;
 			op->type = MKOP(STORE_VSX, 0, 8);
@@ -2794,6 +2832,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 
 		case 3:		/* stxssp with LSB of DS field = 0 */
 		case 7:		/* stxssp with LSB of DS field = 1 */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->ea = dsform_ea(word, regs);
 			op->reg = rd + 32;
 			op->type = MKOP(STORE_VSX, 0, 4);
@@ -2802,6 +2842,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 5:		/* stxv */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->ea = dqform_ea(word, regs);
 			if (word & 8)
 				op->reg = rd + 32;

Re: [PATCH v3] [PATCH] powerpc/sstep: Check ISA 3.0 instruction validity before emulation

From: Naveen N. Rao <hidden>
Date: 2021-01-20 13:53:28 

On 2021/01/20 04:43PM, Ananth N Mavinakayanahalli wrote:
We currently unconditionally try to emulate newer instructions on older
Power versions that could cause issues. Gate it.

Signed-off-by: Ananth N Mavinakayanahalli <redacted>
---

[v3] Addressed Naveen's comments on scv and addpcis
[v2] Fixed description

 arch/powerpc/lib/sstep.c |   46 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)
Reviewed-by: Naveen N. Rao <redacted>

- Naveen

Re: [PATCH v3] [PATCH] powerpc/sstep: Check ISA 3.0 instruction validity before emulation

From: Michal Suchánek <hidden>
Date: 2021-01-20 16:11:25 

On Wed, Jan 20, 2021 at 04:43:14PM +0530, Ananth N Mavinakayanahalli wrote:
We currently unconditionally try to emulate newer instructions on older
Power versions that could cause issues. Gate it.
Fixes: 350779a29f11 ("powerpc: Handle most loads and stores in instruction emulation code")

There are more that would apply but most of the checks land in code
added by the above.

Thanks

Michal
quoted hunk
Signed-off-by: Ananth N Mavinakayanahalli <redacted>
---

[v3] Addressed Naveen's comments on scv and addpcis
[v2] Fixed description

 arch/powerpc/lib/sstep.c |   46 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index bf7a7d62ae8b..5a425a4a1d88 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -1304,9 +1304,11 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 		if ((word & 0xfe2) == 2)
 			op->type = SYSCALL;
 		else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) &&
-				(word & 0xfe3) == 1)
+				(word & 0xfe3) == 1) {	/* scv */
 			op->type = SYSCALL_VECTORED_0;
-		else
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
+		} else
 			op->type = UNKNOWN;
 		return 0;
 #endif
@@ -1530,6 +1532,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 	case 19:
 		if (((word >> 1) & 0x1f) == 2) {
 			/* addpcis */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			imm = (short) (word & 0xffc1);	/* d0 + d2 fields */
 			imm |= (word >> 15) & 0x3e;	/* d1 field */
 			op->val = regs->nip + (imm << 16) + 4;
@@ -2439,6 +2443,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 268:	/* lxvx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(LOAD_VSX, 0, 16);
 			op->element_size = 16;
@@ -2448,6 +2454,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 		case 269:	/* lxvl */
 		case 301: {	/* lxvll */
 			int nb;
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->ea = ra ? regs->gpr[ra] : 0;
 			nb = regs->gpr[rb] & 0xff;
@@ -2475,6 +2483,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 364:	/* lxvwsx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(LOAD_VSX, 0, 4);
 			op->element_size = 4;
@@ -2482,6 +2492,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 396:	/* stxvx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(STORE_VSX, 0, 16);
 			op->element_size = 16;
@@ -2491,6 +2503,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 		case 397:	/* stxvl */
 		case 429: {	/* stxvll */
 			int nb;
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->ea = ra ? regs->gpr[ra] : 0;
 			nb = regs->gpr[rb] & 0xff;
@@ -2542,6 +2556,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 781:	/* lxsibzx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(LOAD_VSX, 0, 1);
 			op->element_size = 8;
@@ -2549,6 +2565,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 812:	/* lxvh8x */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(LOAD_VSX, 0, 16);
 			op->element_size = 2;
@@ -2556,6 +2574,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 813:	/* lxsihzx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(LOAD_VSX, 0, 2);
 			op->element_size = 8;
@@ -2569,6 +2589,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 876:	/* lxvb16x */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(LOAD_VSX, 0, 16);
 			op->element_size = 1;
@@ -2582,6 +2604,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 909:	/* stxsibx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(STORE_VSX, 0, 1);
 			op->element_size = 8;
@@ -2589,6 +2613,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 940:	/* stxvh8x */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(STORE_VSX, 0, 16);
 			op->element_size = 2;
@@ -2596,6 +2622,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 941:	/* stxsihx */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(STORE_VSX, 0, 2);
 			op->element_size = 8;
@@ -2609,6 +2637,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 1004:	/* stxvb16x */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd | ((word & 1) << 5);
 			op->type = MKOP(STORE_VSX, 0, 16);
 			op->element_size = 1;
@@ -2717,12 +2747,16 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			op->type = MKOP(LOAD_FP, 0, 16);
 			break;
 		case 2:		/* lxsd */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd + 32;
 			op->type = MKOP(LOAD_VSX, 0, 8);
 			op->element_size = 8;
 			op->vsx_flags = VSX_CHECK_VEC;
 			break;
 		case 3:		/* lxssp */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->reg = rd + 32;
 			op->type = MKOP(LOAD_VSX, 0, 4);
 			op->element_size = 8;
@@ -2775,6 +2809,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 1:		/* lxv */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->ea = dqform_ea(word, regs);
 			if (word & 8)
 				op->reg = rd + 32;
@@ -2785,6 +2821,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 
 		case 2:		/* stxsd with LSB of DS field = 0 */
 		case 6:		/* stxsd with LSB of DS field = 1 */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->ea = dsform_ea(word, regs);
 			op->reg = rd + 32;
 			op->type = MKOP(STORE_VSX, 0, 8);
@@ -2794,6 +2832,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 
 		case 3:		/* stxssp with LSB of DS field = 0 */
 		case 7:		/* stxssp with LSB of DS field = 1 */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->ea = dsform_ea(word, regs);
 			op->reg = rd + 32;
 			op->type = MKOP(STORE_VSX, 0, 4);
@@ -2802,6 +2842,8 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 			break;
 
 		case 5:		/* stxv */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -1;
 			op->ea = dqform_ea(word, regs);
 			if (word & 8)
 				op->reg = rd + 32;

Re: [PATCH v3] [PATCH] powerpc/sstep: Check ISA 3.0 instruction validity before emulation

From: Sandipan Das <hidden>
Date: 2021-01-21 04:38:53 

On 20/01/21 4:43 pm, Ananth N Mavinakayanahalli wrote:
We currently unconditionally try to emulate newer instructions on older
Power versions that could cause issues. Gate it.

Signed-off-by: Ananth N Mavinakayanahalli <redacted>
---

[v3] Addressed Naveen's comments on scv and addpcis
[v2] Fixed description

 arch/powerpc/lib/sstep.c |   46 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)
Reviewed-by: Sandipan Das <redacted>
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