1 files changed, 63 insertions, 20 deletions

diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index 298dc33737b0..39c946fce939 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -195,7 +195,7 @@ struct mips_frame_info {
 #define J_TARGET(pc,target)	\
 		(((unsigned long)(pc) & 0xf0000000) | ((target) << 2))
 
-static inline int is_ra_save_ins(union mips_instruction *ip)
+static inline int is_ra_save_ins(union mips_instruction *ip, int *poff)
 {
 #ifdef CONFIG_CPU_MICROMIPS
 	/*
@@ -208,25 +208,70 @@ static inline int is_ra_save_ins(union mips_instruction *ip)
 	 * microMIPS is way more fun...
 	 */
 	if (mm_insn_16bit(ip->halfword[1])) {
-		return (ip->mm16_r5_format.opcode == mm_swsp16_op &&
-			ip->mm16_r5_format.rt == 31) ||
-		       (ip->mm16_m_format.opcode == mm_pool16c_op &&
-			ip->mm16_m_format.func == mm_swm16_op);
+		switch (ip->mm16_r5_format.opcode) {
+		case mm_swsp16_op:
+			if (ip->mm16_r5_format.rt != 31)
+				return 0;
+
+			*poff = ip->mm16_r5_format.simmediate;
+			*poff = (*poff << 2) / sizeof(ulong);
+			return 1;
+
+		case mm_pool16c_op:
+			switch (ip->mm16_m_format.func) {
+			case mm_swm16_op:
+				*poff = ip->mm16_m_format.imm;
+				*poff += 1 + ip->mm16_m_format.rlist;
+				*poff = (*poff << 2) / sizeof(ulong);
+				return 1;
+
+			default:
+				return 0;
+			}
+
+		default:
+			return 0;
+		}
 	}
-	else {
-		return (ip->mm_m_format.opcode == mm_pool32b_op &&
-			ip->mm_m_format.rd > 9 &&
-			ip->mm_m_format.base == 29 &&
-			ip->mm_m_format.func == mm_swm32_func) ||
-		       (ip->i_format.opcode == mm_sw32_op &&
-			ip->i_format.rs == 29 &&
-			ip->i_format.rt == 31);
+
+	switch (ip->i_format.opcode) {
+	case mm_sw32_op:
+		if (ip->i_format.rs != 29)
+			return 0;
+		if (ip->i_format.rt != 31)
+			return 0;
+
+		*poff = ip->i_format.simmediate / sizeof(ulong);
+		return 1;
+
+	case mm_pool32b_op:
+		switch (ip->mm_m_format.func) {
+		case mm_swm32_func:
+			if (ip->mm_m_format.rd < 0x10)
+				return 0;
+			if (ip->mm_m_format.base != 29)
+				return 0;
+
+			*poff = ip->mm_m_format.simmediate;
+			*poff += (ip->mm_m_format.rd & 0xf) * sizeof(u32);
+			*poff /= sizeof(ulong);
+			return 1;
+		default:
+			return 0;
+		}
+
+	default:
+		return 0;
 	}
 #else
 	/* sw / sd $ra, offset($sp) */
-	return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) &&
-		ip->i_format.rs == 29 &&
-		ip->i_format.rt == 31;
+	if ((ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) &&
+		ip->i_format.rs == 29 && ip->i_format.rt == 31) {
+		*poff = ip->i_format.simmediate / sizeof(ulong);
+		return 1;
+	}
+
+	return 0;
 #endif
 }
 
@@ -349,11 +394,9 @@ static int get_frame_info(struct mips_frame_info *info)
 			}
 			continue;
 		}
-		if (info->pc_offset == -1 && is_ra_save_ins(&insn)) {
-			info->pc_offset =
-				ip->i_format.simmediate / sizeof(long);
+		if (info->pc_offset == -1 &&
+		    is_ra_save_ins(&insn, &info->pc_offset))
 			break;
-		}
 	}
 	if (info->frame_size && info->pc_offset >= 0) /* nested */
 		return 0;