From: Sergey Kaplun via Tarantool-patches <tarantool-patches@dev.tarantool.org> To: Maxim Kokryashkin <m.kokryashkin@tarantool.org>, Sergey Bronnikov <sergeyb@tarantool.org> Cc: tarantool-patches@dev.tarantool.org Subject: [Tarantool-patches] [PATCH luajit] Add missing coercion when recording select(string, ...) Date: Mon, 23 Sep 2024 14:28:52 +0300 [thread overview] Message-ID: <20240923112852.26851-1-skaplun@tarantool.org> (raw) From: Mike Pall <mike> Thanks to Peter Cawley. (cherry picked from commit 92b89d005ab721a61bce6d471b052bcb236b81d7) Before the patch, the recording of `select()` with a string argument leads to the following IR: | rcx > int CONV "1" int.num index Where the operand has string type instead of number type. This leads to the corresponding mcode: | cvttsd2si ecx, xmm1 Where xmm1 has an undefined value. Thus leads to the undefined behaviour for the recording trace. This patch adds the missing coercion. Sergey Kaplun: * added the description and the test for the problem Part of tarantool/tarantool#10199 --- Branch: https://github.com/tarantool/luajit/tree/skaplun/lj-1083-missing-tostring-coercion-in-select Related issues: * https://github.com/tarantool/tarantool/issues/10199 * https://github.com/LuaJIT/LuaJIT/issues/1083 src/lj_record.c | 5 ++- ...ssing-tostring-coercion-in-select.test.lua | 39 +++++++++++++++++++ 2 files changed, 43 insertions(+), 1 deletion(-) create mode 100644 test/tarantool-tests/lj-1083-missing-tostring-coercion-in-select.test.lua diff --git a/src/lj_record.c b/src/lj_record.c index 96fe26d8..311d9fe7 100644 --- a/src/lj_record.c +++ b/src/lj_record.c @@ -1871,8 +1871,11 @@ static void rec_varg(jit_State *J, BCReg dst, ptrdiff_t nresults) TRef tr = TREF_NIL; ptrdiff_t idx = lj_ffrecord_select_mode(J, tridx, &J->L->base[dst-1]); if (idx < 0) goto nyivarg; - if (idx != 0 && !tref_isinteger(tridx)) + if (idx != 0 && !tref_isinteger(tridx)) { + if (tref_isstr(tridx)) + tridx = emitir(IRTG(IR_STRTO, IRT_NUM), tridx, 0); tridx = emitir(IRTGI(IR_CONV), tridx, IRCONV_INT_NUM|IRCONV_INDEX); + } if (idx != 0 && tref_isk(tridx)) { emitir(IRTGI(idx <= nvararg ? IR_GE : IR_LT), fr, lj_ir_kint(J, frofs+8*(int32_t)idx)); diff --git a/test/tarantool-tests/lj-1083-missing-tostring-coercion-in-select.test.lua b/test/tarantool-tests/lj-1083-missing-tostring-coercion-in-select.test.lua new file mode 100644 index 00000000..8089247f --- /dev/null +++ b/test/tarantool-tests/lj-1083-missing-tostring-coercion-in-select.test.lua @@ -0,0 +1,39 @@ +local tap = require('tap') + +-- Test file to demonstrate LuaJIT incorrect recording of +-- `select()` fast function. +-- See also: https://github.com/LuaJIT/LuaJIT/issues/1083. + +local test = tap.test('lj-1083-missing-tostring-coercion-in-select'):skipcond({ + ['Test requires JIT enabled'] = not jit.status(), +}) + +test:plan(1) + +-- Simplify the `jit.dump()` output. +local select = select + +local function test_select(...) + local result + for _ = 1, 4 do + -- Before the patch, with the missed coercion to string, the + -- recording of `select()` below leads to the following IR: + -- | rcx > int CONV "1" int.num index + -- Where the operand has string type instead of number type. + -- This leads to the corresponding mcode: + -- | cvttsd2si ecx, xmm1 + -- Where xmm1 has an undefined value. Thus leads to the + -- incorrect result for the call below. + result = select('1', ...) + end + return result +end + +jit.opt.start('hotloop=1') + +-- XXX: amount of arguments is empirical, see the comment above. +local result = test_select(1, 2, 3, 4) + +test:is(result, 1, 'corect select result after recording') + +test:done(true) -- 2.46.0
next reply other threads:[~2024-09-23 11:29 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-09-23 11:28 Sergey Kaplun via Tarantool-patches [this message] 2024-09-24 10:28 ` Sergey Bronnikov via Tarantool-patches 2024-09-24 10:33 ` Sergey Kaplun via Tarantool-patches 2024-10-11 19:04 ` Maxim Kokryashkin via Tarantool-patches 2024-10-18 15:17 ` Sergey Kaplun via Tarantool-patches
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