diff options
| author | Mike Pall <mike> | 2020-09-27 16:44:13 +0200 |
|---|---|---|
| committer | Mike Pall <mike> | 2020-09-27 16:44:13 +0200 |
| commit | e8ec6fe996cf48ef23755581dafe372eb71ad75c (patch) | |
| tree | 69e0d40f53cf99bfa9f12e8dbd09a7badccacba7 /src/lj_asm_mips.h | |
| parent | 881d02d3117838acaf4fb844332c8e33cc95c8c5 (diff) | |
| download | luajit2-e8ec6fe996cf48ef23755581dafe372eb71ad75c.tar.gz | |
Prevent patching of the GC exit check branch.
Reported by Arseny Vakhrushev.
Diffstat (limited to 'src/lj_asm_mips.h')
| -rw-r--r-- | src/lj_asm_mips.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/lj_asm_mips.h b/src/lj_asm_mips.h index 190a55eb..22031d11 100644 --- a/src/lj_asm_mips.h +++ b/src/lj_asm_mips.h @@ -1665,6 +1665,9 @@ static void asm_stack_restore(ASMState *as, SnapShot *snap) /* -- GC handling --------------------------------------------------------- */ +/* Marker to prevent patching the GC check exit. */ +#define MIPS_NOPATCH_GC_CHECK MIPSI_OR + /* Check GC threshold and do one or more GC steps. */ static void asm_gc_check(ASMState *as) { @@ -1680,6 +1683,7 @@ static void asm_gc_check(ASMState *as) args[0] = ASMREF_TMP1; /* global_State *g */ args[1] = ASMREF_TMP2; /* MSize steps */ asm_gencall(as, ci, args); + l_end[-3] = MIPS_NOPATCH_GC_CHECK; /* Replace the nop after the call. */ emit_tsi(as, MIPSI_ADDIU, ra_releasetmp(as, ASMREF_TMP1), RID_JGL, -32768); tmp = ra_releasetmp(as, ASMREF_TMP2); emit_loadi(as, tmp, as->gcsteps); @@ -1936,7 +1940,8 @@ void lj_asm_patchexit(jit_State *J, GCtrace *T, ExitNo exitno, MCode *target) if (((p[-1] ^ (px-p)) & 0xffffu) == 0 && ((p[-1] & 0xf0000000u) == MIPSI_BEQ || (p[-1] & 0xfc1e0000u) == MIPSI_BLTZ || - (p[-1] & 0xffe00000u) == MIPSI_BC1F)) { + (p[-1] & 0xffe00000u) == MIPSI_BC1F) && + p[-2] != MIPS_NOPATCH_GC_CHECK) { ptrdiff_t delta = target - p; if (((delta + 0x8000) >> 16) == 0) { /* Patch in-range branch. */ patchbranch: |