From: Sergey Kaplun via Tarantool-patches <tarantool-patches@dev.tarantool.org> To: Igor Munkin <imun@tarantool.org>, Maxim Kokryashkin <m.kokryashkin@tarantool.org> Cc: tarantool-patches@dev.tarantool.org Subject: [Tarantool-patches] [PATCH luajit 1/2] Fix maxslots when recording BC_VARG. Date: Mon, 10 Jul 2023 13:46:48 +0300 [thread overview] Message-ID: <323f1c0c6a33a31f0ad7691bd68886bfd195eae4.1688985402.git.skaplun@tarantool.org> (raw) In-Reply-To: <cover.1688985402.git.skaplun@tarantool.org> From: Mike Pall <mike> Analyzed by Sergey Kaplun. (cherry-picked from commit 94ada59628dd6ce5d6d2dad1d35a68ad30127f53) While recording BC_VARG `J->maxslot` isn't shrunk to the effective stack top. This leads to dead value stored in the JIT slots and the following assertion failure for these slots check in `rec_check_slots()`. Note, that `rec_varg()` modifies `maxslot` only under the condition that `maxslot` should be increased, but the dead values are left for the opposite case. This patch removes the condition inside `rec_varg()` only for the case when varargs are not defined on trace (`framedepth` is 0), but the similar issue still occurs for the case when vararg are defined on the trace. Sergey Kaplun: * added the description and the test for the problem Part of tarantool/tarantool#8825 --- src/lj_record.c | 3 +-- .../lj-1024-varg-maxslot.test.lua | 23 +++++++++++++++++++ 2 files changed, 24 insertions(+), 2 deletions(-) create mode 100644 test/tarantool-tests/lj-1024-varg-maxslot.test.lua diff --git a/src/lj_record.c b/src/lj_record.c index a90cba77..112524d3 100644 --- a/src/lj_record.c +++ b/src/lj_record.c @@ -1812,8 +1812,7 @@ static void rec_varg(jit_State *J, BCReg dst, ptrdiff_t nresults) } for (i = nvararg; i < nresults; i++) J->base[dst+i] = TREF_NIL; - if (dst + (BCReg)nresults > J->maxslot) - J->maxslot = dst + (BCReg)nresults; + J->maxslot = dst + (BCReg)nresults; } else if (select_detect(J)) { /* y = select(x, ...) */ TRef tridx = J->base[dst-1]; TRef tr = TREF_NIL; diff --git a/test/tarantool-tests/lj-1024-varg-maxslot.test.lua b/test/tarantool-tests/lj-1024-varg-maxslot.test.lua new file mode 100644 index 00000000..14270595 --- /dev/null +++ b/test/tarantool-tests/lj-1024-varg-maxslot.test.lua @@ -0,0 +1,23 @@ +local tap = require('tap') +local test = tap.test('lj-noticket-varg-usedef'):skipcond({ + ['Test requires JIT enabled'] = not jit.status(), +}) + +test:plan(1) + +jit.opt.start('hotloop=1') + +local counter = 0 +-- luacheck: ignore +local anchor +while counter < 3 do + counter = counter + 1 + -- BC_VARG 5 1 0. `...` is nil (argument for the script). + -- luacheck: ignore + -- XXX: some condition to use several slots on the Lua stack. + anchor = 1 >= 1, ... +end + +test:ok(true, 'BC_VARG recording 0th frame depth') + +os.exit(test:check() and 0 or 1) -- 2.34.1
next prev parent reply other threads:[~2023-07-10 10:51 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-07-10 10:46 [Tarantool-patches] [PATCH luajit 0/2] " Sergey Kaplun via Tarantool-patches 2023-07-10 10:46 ` Sergey Kaplun via Tarantool-patches [this message] 2023-07-14 12:16 ` [Tarantool-patches] [PATCH luajit 1/2] " Maxim Kokryashkin via Tarantool-patches 2023-07-15 15:11 ` Sergey Kaplun via Tarantool-patches 2023-07-17 11:00 ` Maxim Kokryashkin via Tarantool-patches 2023-07-18 8:18 ` Igor Munkin via Tarantool-patches 2023-07-18 14:12 ` Sergey Kaplun via Tarantool-patches 2023-07-18 14:23 ` Igor Munkin via Tarantool-patches 2023-07-10 10:46 ` [Tarantool-patches] [PATCH luajit 2/2] Fix maxslots when recording BC_VARG, part 2 Sergey Kaplun via Tarantool-patches 2023-07-14 12:41 ` Maxim Kokryashkin via Tarantool-patches 2023-07-15 15:08 ` Sergey Kaplun via Tarantool-patches 2023-07-17 11:03 ` Maxim Kokryashkin via Tarantool-patches 2023-07-18 8:18 ` Igor Munkin via Tarantool-patches 2023-07-18 14:19 ` Sergey Kaplun via Tarantool-patches 2023-07-18 14:24 ` Igor Munkin via Tarantool-patches 2023-07-20 18:37 ` [Tarantool-patches] [PATCH luajit 0/2] Fix maxslots when recording BC_VARG Igor Munkin via Tarantool-patches
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