[Tarantool-patches] [PATCH luajit 1/3][v3] MIPS64: Fix xpcall() error case.

[Sergey Bronnikov via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

From: Mike Pall <mike>

Thanks to François Perrad and Stefan Pejic.

(cherry picked from commit ea7071d3c30b6432bfe6f8a9d263e0285cec25e3)

The patch fixes `xpcall()` segfaults on MIPS64 architecture.
The similar patch for ARM64 has been backported (with the test)
previously, see the commit af889e4608e6eca495dd85e6161d8bcd7d3628e6
("ARM64: Fix xpcall() error case (really).").

Sergey Bronnikov:
* added the description

Part of tarantool/tarantool#12134
---
 src/vm_mips64.dasc | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/vm_mips64.dasc b/src/vm_mips64.dasc
index 44fba36c..da187a7a 100644
--- a/src/vm_mips64.dasc
+++ b/src/vm_mips64.dasc
@@ -1440,15 +1440,16 @@ static void build_subroutines(BuildCtx *ctx)
   |.  nop
   |
   |.ffunc xpcall
-  |  daddiu NARGS8:RC, NARGS8:RC, -16
+  |  daddiu NARGS8:TMP0, NARGS8:RC, -16
   |  ld CARG1, 0(BASE)
   |   ld CARG2, 8(BASE)
-  |    bltz NARGS8:RC, ->fff_fallback
+  |    bltz NARGS8:TMP0, ->fff_fallback
   |.    lbu TMP1, DISPATCH_GL(hookmask)(DISPATCH)
   |  gettp AT, CARG2
   |  daddiu AT, AT, -LJ_TFUNC
   |  bnez AT, ->fff_fallback		// Traceback must be a function.
   |.   move TMP2, BASE
+  |  move NARGS8:RC, NARGS8:TMP0
   |   daddiu BASE, BASE, 24
   |  // Remember active hook before pcall.
   |  srl TMP3, TMP3, HOOK_ACTIVE_SHIFT
-- 
2.43.0