From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [87.239.111.99] (localhost [127.0.0.1]) by dev.tarantool.org (Postfix) with ESMTP id B248FEF8D2A; Thu, 6 Feb 2025 11:01:26 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 dev.tarantool.org B248FEF8D2A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=tarantool.org; s=dev; t=1738828886; bh=HXBvgWGOBfybOmVlFHYvwF1yIlQx/2qCFB1dQyx/s6g=; h=To:Date:Subject:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=ltzzqCp6eLDNVis2cqcvm8BeKwAR9hwKYit6B2xTpPJ+owco88mIFt+mNPE8vX0f1 d2DsoNFP/H4EtH2hmlxCkodhzXdXyShPVIf/G8Q8xv8M0tQlfcChy5iG/5osVCFnK6 wfvtJrQ7s/krPJay94Q1cx++ZuFlIruf+oLT51NQ= Received: from mail-lf1-f49.google.com (mail-lf1-f49.google.com [209.85.167.49]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id C81946DB22 for ; Thu, 6 Feb 2025 11:01:24 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 dev.tarantool.org C81946DB22 Received: by mail-lf1-f49.google.com with SMTP id 2adb3069b0e04-53f22fd6832so709617e87.1 for ; Thu, 06 Feb 2025 00:01:24 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738828884; x=1739433684; h=content-transfer-encoding:mime-version:message-id:date:subject:to :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=tRhcONOd9VtNXJ7MDLUoVhBMcZ+dsFSBOV6HsTFdOys=; b=RR1xRaeW1HDYFutFY5VX7jCbecinpGvwcU8Pqik++rGt5RgNjVBPMYv5xu1z1z1Nvr 4u5Xt620Q9dV+7W8vS/1qBTx67uWHa4Bg20BbR/81CcbEqDmbU1KS2pQ4m6FNUHcUYIP Ry939ATOzEwHE0VsjHVzHuYzB8PQIB/C7gbCa/ZcEpYrLAjXizg+vALpTFuYKa9hguTR U/0G1jWJUKBwtzh6qfC8vxw1OpifASWtSdGBB/ETE5Ecgl1HgohUTMLlXv5HJ3YVxvfq 4XPJzm+ghFzYBTpzXRtJ/ttBkJoq16+Kusy7TEdOUtZPtzmCMQGe91X5leh7CRW8FtNU bVRA== X-Gm-Message-State: AOJu0Ywi8R8HcQ/vxOM19aIN165akVL9cvg0GjjwTs4kDn7eft9eQPy0 UfdS7wjHRaE+Fif19q66CggeSLvkSQ0R84vuOHMMQ0rPw2nPbj4B/Kl/uhNL X-Gm-Gg: ASbGncuUV6E+HZnk1Yz7mE8pvtJebE87MmVHWIJYTD3x+c48CPmbx3sfWlfsRE0rdmT yepoZepsMrqAQ9GUFplifvZW/nFRhsG/GHVkIfEpg7DStuXId9i6Xvg34HdBTwVKeHVPU9OGFuk d6riB9xmDbaJDO9zOohcqRJ2la/5Hc9iinP4W41VNEhI4vGTZkWtj8jhz3P0xPVKe/Giqp6yqhq +ssfNYOXez6kcqGtVSPKqPN0a2pxZCH9Cjji1h8FKIZ7jRUzuPkqflP8dzsu7PDYoJeYQOPMogc 2cvf3Q== X-Google-Smtp-Source: AGHT+IE8L2Wp1bZ+Gh3wkzhFP5k31Y7PqztMbFiJ/1FUATq+VAnC+dJEj2mKKQrHm1aY/MyK+ge9dA== X-Received: by 2002:a05:6512:3f07:b0:542:2a29:88ed with SMTP id 2adb3069b0e04-54405a68aecmr2020086e87.44.1738828883395; Thu, 06 Feb 2025 00:01:23 -0800 (PST) Received: from localhost ([5.181.62.98]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-5441053ea84sm68641e87.35.2025.02.06.00.01.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Feb 2025 00:01:21 -0800 (PST) X-Google-Original-From: Sergey Bronnikov To: tarantool-patches@dev.tarantool.org, Sergey Kaplun Date: Thu, 6 Feb 2025 10:57:19 +0300 Message-Id: X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [Tarantool-patches] [PATCH luajit][v2] Handle all stack layouts in (delayed) TRACE vmevent. X-BeenThere: tarantool-patches@dev.tarantool.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Sergey Bronnikov via Tarantool-patches Reply-To: Sergey Bronnikov Errors-To: tarantool-patches-bounces@dev.tarantool.org Sender: "Tarantool-patches" From: Mike Pall Thanks to Sergey Bronnikov and Peter Cawley. (cherry picked from commit b138ccfa918518a152bc830fef3d53cd0a922e36) When recording a trace using a Lua code like `repeat until `a >= 'b' > 'b'` a Lua error is encountered (`attempt to compare string with nil`), which (along with raising the error) causes an asynchronous trace abort. The trace abort remains pending until the next reentrance to the LuaJIT VM via `lj_vm_call()` or `lj_vm_pcall(). On handling abort LuaJIT is searching for the topmost Lua frame on the stack, that was active when the trace abort happened, it is needed to generate a better error message. Unfortunately, because the abort was due to an error, and the error was caught by a `lua_pcall` with an unspecified error function (4th argument), the Lua frame that caused the abort was already removed as part of error processing, so the search cannot find it. Furthermore, in this particular case, there are no Lua frames on the stack, which isn't something the search code had considered possible. Sergey Bronnikov: * added the description and the test for the problem Part of tarantool/tarantool#11055 --- Branch: https://github.com/tarantool/luajit/tree/ligurio/lj-1087-vm-handler-call Related issues: - https://github.com/LuaJIT/LuaJIT/issues/1087 - https://github.com/tarantool/tarantool/issues/10709 Changes in the v2: * Addressed comments by Sergey Kaplun src/lj_trace.c | 26 +-- .../lj-1087-vm-handler-call.test.c | 170 ++++++++++++++++++ 2 files changed, 186 insertions(+), 10 deletions(-) create mode 100644 test/tarantool-c-tests/lj-1087-vm-handler-call.test.c diff --git a/src/lj_trace.c b/src/lj_trace.c index 94cb27e5..6b97cc13 100644 --- a/src/lj_trace.c +++ b/src/lj_trace.c @@ -616,21 +616,27 @@ static int trace_abort(jit_State *J) J->cur.link = 0; J->cur.linktype = LJ_TRLINK_NONE; lj_vmevent_send(L, TRACE, - TValue *frame; + cTValue *bot = tvref(L->stack)+LJ_FR2; + cTValue *frame; const BCIns *pc; - GCfunc *fn; + BCPos pos = 0; setstrV(L, L->top++, lj_str_newlit(L, "abort")); setintV(L->top++, traceno); /* Find original Lua function call to generate a better error message. */ - frame = J->L->base-1; - pc = J->pc; - while (!isluafunc(frame_func(frame))) { - pc = (frame_iscont(frame) ? frame_contpc(frame) : frame_pc(frame)) - 1; - frame = frame_prev(frame); + for (frame = J->L->base-1, pc = J->pc; ; frame = frame_prev(frame)) { + if (isluafunc(frame_func(frame))) { + pos = proto_bcpos(funcproto(frame_func(frame)), pc); + break; + } else if (frame_prev(frame) <= bot) { + break; + } else if (frame_iscont(frame)) { + pc = frame_contpc(frame) - 1; + } else { + pc = frame_pc(frame) - 1; + } } - fn = frame_func(frame); - setfuncV(L, L->top++, fn); - setintV(L->top++, proto_bcpos(funcproto(fn), pc)); + setfuncV(L, L->top++, frame_func(frame)); + setintV(L->top++, pos); copyTV(L, L->top++, restorestack(L, errobj)); copyTV(L, L->top++, &J->errinfo); ); diff --git a/test/tarantool-c-tests/lj-1087-vm-handler-call.test.c b/test/tarantool-c-tests/lj-1087-vm-handler-call.test.c new file mode 100644 index 00000000..ebdf63e1 --- /dev/null +++ b/test/tarantool-c-tests/lj-1087-vm-handler-call.test.c @@ -0,0 +1,170 @@ +#include "lua.h" +#include "lauxlib.h" + +#include "test.h" +#include "utils.h" + +/* Need for skipcond for BSD and JIT. */ +#include "lj_arch.h" + +/* XXX: Still need normal assert inside writer functions. */ +#undef NDEBUG +#include + +/* + * Test file to demonstrate a segmentation fault, when C function + * is used as a VM handler in LuaJIT: + * + * Program received signal SIGSEGV, Segmentation fault. + * 0x000055555557e77d in trace_abort (J=0x7ffff7f9b6b8) at lj_trace.c:615 + * 615 lj_vmevent_send(L, TRACE, + * (gdb) bt + * + * See details in https://github.com/LuaJIT/LuaJIT/issues/1087. + */ + +static int nop(lua_State *L) +{ + UNUSED(L); + return 0; +} + +/* Note, `event == NULL` disables the corresponding handler. */ +static void jit_attach(lua_State *L, lua_CFunction cb, const char *event) +{ + lua_getglobal(L, "jit"); + lua_getfield(L, -1, "attach"); + lua_pushcfunction(L, cb); + if (event != NULL) + lua_pushstring(L, event); + else + lua_pushnil(L); + lua_pcall(L, 2, 0, 0); +} + +static int handle_luafunc_frame(void *test_state) +{ + /* Setup. */ + lua_State *L = test_state; + jit_attach(L, nop, "trace"); + + /* Loading and executing of a broken Lua code. */ + int rc = luaL_dostring(L, "repeat until nil > 1"); + assert(rc == 1); + + /* The Lua chunk generates a Lua frame. */ + rc = luaL_dostring(L, "return function() end"); + assert(rc == 0); + + /* Teardown. */ + lua_settop(L, 0); + + return TEST_EXIT_SUCCESS; +} + +static int cframe(lua_State *L) +{ + int rc = luaL_dostring(L, "repeat until nil > 1"); + assert(rc == 1); + /* Remove errmsg. */ + lua_pop(L, 1); + + lua_pushcfunction(L, nop); + lua_call(L, 0, 0); + + return 0; +} + +static int handle_c_frame(void *test_state) +{ + /* Setup. */ + lua_State *L = test_state; + jit_attach(L, nop, "trace"); + + lua_pushcfunction(L, cframe); + lua_call(L, 0, 0); + + /* Teardown. */ + lua_settop(L, 0); + + return TEST_EXIT_SUCCESS; +} + +static int handle_cont_frame(void *test_state) +{ + const char lua_chunk[] = + "local t = setmetatable({}, { __index = global_f })" + "for i = 1, 4 do" + " _ = t[1]" + "end"; + + /* Setup. */ + lua_State *L = test_state; + jit_attach(L, nop, "trace"); + + /* + * The number 32767 is `REF_DROP - REF_BIAS`. See the commit + * 0fdf06b456e6 ("test: relax JIT setup in misc.getmetrics + * test") for the details. + */ + int res = luaL_dostring(L, "jit.opt.start('minstitch=32767')"); + assert(res == 0); + lua_pushcfunction(L, nop); + lua_setglobal(L, "global_f"); + + res = luaL_dostring(L, lua_chunk); + assert(res == 0); + + /* Teardown. */ + lua_settop(L, 0); + res = luaL_dostring(L, "jit.opt.start('minstitch=0')"); + assert(res == 0); + + return TEST_EXIT_SUCCESS; +} + +static int handle_bottom_frame(void *test_state) +{ + lua_State *L = test_state; + + /* Attach VM call handler. */ + jit_attach(L, nop, "trace"); + + /* Load a Lua code that generate a trace abort. */ + int rc = luaL_dostring(L, "repeat until nil > 1"); + assert(rc == 1); + + /* + * Note, protected call is used inside `jit_attach()` to + * return to the VM on disabling the handler. Then + * a segmentation fault is triggered. + */ + jit_attach(L, nop, NULL); + + /* Teardown. */ + lua_settop(L, 0); + + return TEST_EXIT_SUCCESS; +} + +int main(void) +{ + if (!LJ_HASJIT) + return skip_all("JIT is disabled"); + + if (LUAJIT_OS == LUAJIT_OS_BSD) + return skip_all("Disabled on *BSD due to #4819"); + + lua_State *L = utils_lua_init(); + const struct test_unit tgroup[] = { + test_unit_def(handle_luafunc_frame), + test_unit_def(handle_bottom_frame), + test_unit_def(handle_cont_frame), + test_unit_def(handle_c_frame), + }; + int res = luaL_dostring(L, "jit.opt.start('hotloop=1')"); + assert(res == 0); + const int test_result = test_run_group(tgroup, L); + utils_lua_close(L); + return test_result; +} -- 2.34.1