diff mbox series

[V5,2/2] MIPS: Loongson-3: Calculate ra properly when unwinding the stack

Message ID 1599031924-31659-2-git-send-email-chenhc@lemote.com (mailing list archive)
State Superseded
Headers show
Series [V5,1/2] MIPS: Loongson-3: Enable COP2 usage in kernel | expand

Commit Message

Huacai Chen Sept. 2, 2020, 7:32 a.m. UTC 
Loongson-3 has 16-bytes load/store instructions: gslq and gssq. This
patch calculate ra properly when unwinding the stack, if ra is saved
by gssq and restored by gslq.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
---
 arch/mips/kernel/process.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index 9412314..c4e9fd8 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -279,7 +279,21 @@  static inline int is_ra_save_ins(union mips_instruction *ip, int *poff)
 		*poff = ip->i_format.simmediate / sizeof(ulong);
 		return 1;
 	}
-
+#ifdef CONFIG_CPU_LOONGSON64
+	if ((ip->loongson3_lswc2_format.opcode == swc2_op) &&
+		      (ip->loongson3_lswc2_format.ls == 1) &&
+		      (ip->loongson3_lswc2_format.fr == 0) &&
+		      (ip->loongson3_lswc2_format.base == 29)) {
+		if (ip->loongson3_lswc2_format.rt == 31) {
+			*poff = ip->loongson3_lswc2_format.offset << 1;
+			return 1;
+		}
+		if (ip->loongson3_lswc2_format.rq == 31) {
+			*poff = (ip->loongson3_lswc2_format.offset << 1) + 1;
+			return 1;
+		}
+	}
+#endif
 	return 0;
 #endif
 }