Bolsh kgdb helpers

arch/arc/include/asm/disasm.h

@@ -99,7 +99,27 @@ static inline int is_short_instr(unsigned long addr)
 {
 	uint16_t word = *((uint16_t *)addr);
 	int opcode = (word >> 11) & 0x1F;
+#ifdef CONFIG_ISA_ARCOMPACT
 	return (opcode >= 0x0B);
+#elif defined(CONFIG_ISA_ARCV2)
+	return (opcode >= 0x08);
+#else /* CONFIG_ISA_ARCV3 */
+	#ifdef CONFIG_64BIT
+		if (opcode < 8)
+			return 0;
+		else if (opcode == 0xB || opcode == 0xD || opcode == 0x1C)
+			return 0;
+		else
+			return 1;
+	#else
+		if (opcode < 8)
+			return 0;
+		else if (opcode == 0xD || opcode == 0x1C)
+			return 0;
+		else
+			return 1;
+	#endif
+#endif
 }
 
 void disasm_instr(unsigned long addr, struct disasm_state *state,

arch/arc/include/asm/ptrace.h

@@ -67,7 +67,7 @@ struct pt_regs {
 
 	unsigned long bta;	/* erbta */
 
-	unsigned long fp;
+	unsigned long fp;	/* r27 */
 	unsigned long r30;
 	unsigned long r12;
 	unsigned long gp;	/* r26 */
@@ -79,12 +79,12 @@ struct pt_regs {
 	unsigned long DSP_CTRL;
 #endif
 
-	unsigned long sp;	/* user/kernel sp depending on entry  */
+	unsigned long sp;	/* user/kernel sp depending on entry, r28  */
 
 	/*------- Below list auto saved by h/w -----------*/
 	unsigned long r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11;
 
-	unsigned long blink;
+	unsigned long blink;	/* r31 */
 
 #ifndef CONFIG_ARC_LACKS_ZOL
 	unsigned long lp_end, lp_start, lp_count;
@@ -112,13 +112,13 @@ struct pt_regs {
 #endif
 	ecr_reg ecr;
 	unsigned long bta;
-	unsigned long fp;
+	unsigned long fp;	/* r27 */
 	unsigned long gp;	/* r30 */
-	unsigned long sp;
+	unsigned long sp;	/* r28 */
 
 	/*------- Below list auto saved by h/w -----------*/
 	unsigned long r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13;
-	unsigned long blink;
+	unsigned long blink;	/* r31 */
 
 	unsigned long ret;
 	unsigned long status32;

arch/arc/kernel/disasm.c

@@ -48,7 +48,7 @@ void __kprobes disasm_instr(unsigned long addr, struct disasm_state *state,
 	state->major_opcode = (word1 >> 11) & 0x1F;
 
 	/* Check if the instruction is 32 bit or 16 bit instruction */
-	if (state->major_opcode < 0x0B) {
+	if (state->major_opcode < 0x0C) {
 		if (bytes_not_copied > 4)
 			goto fault;
 		state->instr_len = 4;
@@ -434,14 +434,40 @@ long __kprobes get_reg(int reg, struct pt_regs *regs,
 {
 	long *p;
 
+#ifdef CONFIG_ISA_ARCOMPACT
+
 	if (reg <= 12) {
 		p = &regs->r0;
 		return p[-reg];
 	}
 
 	if (cregs && (reg <= 25)) {
 		p = &cregs->r13;
-		return p[13-reg];
+		return p[13 - reg];
+	}
+
+	if (reg == 26)
+		return regs->gp;
+	if (reg == 27)
+		return regs->fp;
+	if (reg == 28)
+		return regs->sp;
+	if (reg == 31)
+		return regs->blink;
+
+#elif defined(CONFIG_ISA_ARCV2)
+
+	if (reg <= 11) {
+		p = &regs->r0;
+		return p[reg];
+	}
+
+	if (reg == 12)
+		return regs->r12;
+
+	if (cregs && (reg <= 25)) {
+		p = &cregs->r13;
+		return p[13 - reg];
 	}
 
 	if (reg == 26)
@@ -453,6 +479,28 @@ long __kprobes get_reg(int reg, struct pt_regs *regs,
 	if (reg == 31)
 		return regs->blink;
 
+#else /* CONFIG_ISA_ARCV3 */
+
+	if (reg <= 13) {
+		p = &regs->r0;
+		return p[reg];
+	}
+
+	if (cregs && (reg <= 26)) {
+		p = &cregs->r14;
+		return p[reg - 14];
+	}
+
+	if (reg == 27)
+		return regs->fp;
+	if (reg == 28)
+		return regs->sp;
+	if (reg == 30)
+		return regs->gp;
+	if (reg == 31)
+		return regs->blink;
+
+#endif
 	return 0;
 }
 
@@ -461,6 +509,8 @@ void __kprobes set_reg(int reg, long val, struct pt_regs *regs,
 {
 	long *p;
 
+#ifdef CONFIG_ISA_ARCOMPACT
+
 	switch (reg) {
 	case 0 ... 12:
 		p = &regs->r0;
@@ -469,7 +519,39 @@ void __kprobes set_reg(int reg, long val, struct pt_regs *regs,
 	case 13 ... 25:
 		if (cregs) {
 			p = &cregs->r13;
-			p[13-reg] = val;
+			p[13 - reg] = val;
+		}
+		break;
+	case 26:
+		regs->gp = val;
+		break;
+	case 27:
+		regs->fp = val;
+		break;
+	case 28:
+		regs->sp = val;
+		break;
+	case 31:
+		regs->blink = val;
+		break;
+	default:
+		break;
+	}
+
+#elif defined(CONFIG_ISA_ARCV2)
+
+	switch (reg) {
+	case 0 ... 11:
+		p = &regs->r0;
+		p[reg] = val;
+		break;
+	case 12:
+		regs->r12 = val;
+		break;
+	case 13 ... 25:
+		if (cregs) {
+			p = &cregs->r13;
+			p[13 - reg] = val;
 		}
 		break;
 	case 26:
@@ -487,6 +569,38 @@ void __kprobes set_reg(int reg, long val, struct pt_regs *regs,
 	default:
 		break;
 	}
+
+#else /* CONFIG_ISA_ARCV3 */
+
+	switch (reg) {
+	case 0 ... 13:
+		p = &regs->r0;
+		p[reg] = val;
+		break;
+	case 14 ... 26:
+		if (cregs) {
+			p = &cregs->r14;
+			p[reg - 14] = val;
+		}
+		break;
+	case 27:
+		regs->fp = val;
+		break;
+	case 28:
+		regs->sp = val;
+		break;
+	case 30:
+		regs->gp = val;
+		break;
+	case 31:
+		regs->blink = val;
+		break;
+	default:
+		break;
+	}
+
+#endif
+
 }
 
 /*

arch/arc/mm/cache-arcv3.c

@@ -613,7 +613,19 @@ void flush_icache_range(unsigned long kvaddr, unsigned long kvend)
 {
 	unsigned int tot_sz = kvend - kvaddr;
 
-	BUG_ON((kvaddr < VMALLOC_START) || (kvend > VMALLOC_END));
+	WARN(kvaddr < TASK_SIZE, "%s() can't handle user vaddr", __func__);
+
+	/* Case: Kernel Phy addr (0x8000_0000 onwards) */
+	if (likely(kvaddr > PAGE_OFFSET)) {
+		/*
+		 * The 2nd arg despite being paddr will be used to index icache
+		 * This is OK since no alternate virtual mappings will exist
+		 * given the callers for this case: kprobe/kgdb in built-in
+		 * kernel code only.
+		 */
+		__sync_icache_dcache(kvaddr, kvaddr, kvend - kvaddr);
+		return;
+	}
 
 	while (tot_sz > 0) {
 		unsigned int off, sz;