[Tarantool-patches] [PATCH v3 luajit] Fix command-line argv handling.

[Tarantool-patches] [PATCH v3 luajit] Fix command-line argv handling.

[Sergey Kaplun via Tarantool-patches]

From: Mike Pall <mike>

(cherry-picked from commit 9ebebc9b588dc1516c988b46d829445f505fdc1f)

Before the patch, there was a situation where `luaL_newstate()` could
fail in `main()` and the `argv[0]` could be used as a progname in
`l_message()`. However, `argv[0]` is not guaranteed to be non-NULL, so
the segmentation fault could occur. This patch fixes the issue by using
the predefined name in that case. Moreover, it refactors the
`l_message()`, so now there is no need to pass the program name
everywhere.

The patch is tested with the help of the mocking of `luaL_newstate` by
providing an error-injected implementation of it and preloading it. For
preload to work, the LuaJIT must be built with dynamic build mode
enabled. The corresponding flavor is added to the CI only for x86_64
Debug build to avoid CI jobs outgrowing.

The <gh-8594-sysprof-ffunc-crash.test.c> inspects internal symbols from
the LuaJIT static library, so it can't be linked for shared build. The
test is disabled for the dynamic build mode.

Since the Linux kernel 5.18-rc1 release, `argv` is forced to a single
empty string if it is empty [1], so the issue is not reproducible on new
kernels. You may inspect the `dmesg` log for the corresponding warning
entrance.

Maxim Kokryashkin:
* added the description and the test for the problem

[1]: https://lore.kernel.org/all/20220201000947.2453721-1-keescook@chromium.org/

Part of tarantool/tarantool#10709
---

Changes in v3:
* Skip only one test from tarantool-c-tests, not the whole suite.
* Skip the added test not inside the main loop, but via adding the
  environment variable.
* Rebased on the current tarantool/master.
* Fix typos.

Branch: https://github.com/tarantool/luajit/tree/fckxorg/fix-argv-handling
Issue: https://github.com/tarantool/tarantool/issues/10709

 .github/workflows/exotic-builds-testing.yml   | 10 ++-
 src/luajit.c                                  | 24 +++----
 test/tarantool-c-tests/CMakeLists.txt         |  8 +++
 test/tarantool-tests/CMakeLists.txt           | 10 +++
 .../fix-argv-handling.test.lua                | 26 +++++++
 .../fix-argv-handling/CMakeLists.txt          |  3 +
 .../fix-argv-handling/execlib.c               | 67 +++++++++++++++++++
 .../fix-argv-handling/mynewstate.c            |  9 +++
 8 files changed, 144 insertions(+), 13 deletions(-)
 create mode 100644 test/tarantool-tests/fix-argv-handling.test.lua
 create mode 100644 test/tarantool-tests/fix-argv-handling/CMakeLists.txt
 create mode 100644 test/tarantool-tests/fix-argv-handling/execlib.c
 create mode 100644 test/tarantool-tests/fix-argv-handling/mynewstate.c

diff --git a/.github/workflows/exotic-builds-testing.yml b/.github/workflows/exotic-builds-testing.yml
index 70096439..374c879b 100644
--- a/.github/workflows/exotic-builds-testing.yml
+++ b/.github/workflows/exotic-builds-testing.yml
@@ -34,7 +34,7 @@ jobs:
         BUILDTYPE: [Debug, Release]
         ARCH: [ARM64, x86_64]
         GC64: [ON, OFF]
-        FLAVOR: [checkhook, dualnum, gdbjit, nojit, nounwind, tablebump]
+        FLAVOR: [checkhook, dualnum, dynamic, gdbjit, nojit, nounwind, tablebump]
         include:
           - BUILDTYPE: Debug
             CMAKEFLAGS: -DCMAKE_BUILD_TYPE=Debug -DLUA_USE_ASSERT=ON -DLUA_USE_APICHECK=ON
@@ -42,6 +42,8 @@ jobs:
             CMAKEFLAGS: -DCMAKE_BUILD_TYPE=RelWithDebInfo
           - FLAVOR: dualnum
             FLAVORFLAGS: -DLUAJIT_NUMMODE=2
+          - FLAVOR: dynamic
+            FLAVORFLAGS: -DBUILDMODE=dynamic
           - FLAVOR: checkhook
             FLAVORFLAGS: -DLUAJIT_ENABLE_CHECKHOOK=ON
           - FLAVOR: nojit
@@ -58,6 +60,12 @@ jobs:
           # DUALNUM is default for ARM64, no need for additional testing.
           - FLAVOR: dualnum
             ARCH: ARM64
+          # There is no need to test any scenarios except the most
+          # common one for the shared library build.
+          - FLAVOR: dynamic
+            ARCH: ARM64
+          - FLAVOR: dynamic
+            BUILDTYPE: Release
           # With table bump optimization enabled (and due to our modification
           # related to metrics), some offsets in GG_State stop fitting in 12bit
           # immediate. Hence, the build failed due to the DASM error
diff --git a/src/luajit.c b/src/luajit.c
index e04a5a30..d9d85361 100644
--- a/src/luajit.c
+++ b/src/luajit.c
@@ -39,6 +39,7 @@
 
 static lua_State *globalL = NULL;
 static const char *progname = LUA_PROGNAME;
+static char *empty_argv[2] = { NULL, NULL };
 
 #if !LJ_TARGET_CONSOLE
 static void lstop(lua_State *L, lua_Debug *ar)
@@ -90,9 +91,9 @@ static void print_tools_usage(void)
   fflush(stderr);
 }
 
-static void l_message(const char *pname, const char *msg)
+static void l_message(const char *msg)
 {
-  if (pname) { fputs(pname, stderr); fputc(':', stderr); fputc(' ', stderr); }
+  if (progname) { fputs(progname, stderr); fputc(':', stderr); fputc(' ', stderr); }
   fputs(msg, stderr); fputc('\n', stderr);
   fflush(stderr);
 }
@@ -102,7 +103,7 @@ static int report(lua_State *L, int status)
   if (status && !lua_isnil(L, -1)) {
     const char *msg = lua_tostring(L, -1);
     if (msg == NULL) msg = "(error object is not a string)";
-    l_message(progname, msg);
+    l_message(msg);
     lua_pop(L, 1);
   }
   return status;
@@ -268,9 +269,8 @@ static void dotty(lua_State *L)
       lua_getglobal(L, "print");
       lua_insert(L, 1);
       if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != 0)
-	l_message(progname,
-	  lua_pushfstring(L, "error calling " LUA_QL("print") " (%s)",
-			      lua_tostring(L, -1)));
+	l_message(lua_pushfstring(L, "error calling " LUA_QL("print") " (%s)",
+				  lua_tostring(L, -1)));
     }
   }
   lua_settop(L, 0);  /* clear stack */
@@ -322,8 +322,7 @@ static int loadjitmodule(lua_State *L)
   lua_getfield(L, -1, "start");
   if (lua_isnil(L, -1)) {
   nomodule:
-    l_message(progname,
-	      "unknown luaJIT command or jit.* modules not installed");
+    l_message("unknown luaJIT command or jit.* modules not installed");
     return 1;
   }
   lua_remove(L, -2);  /* Drop module table. */
@@ -383,7 +382,7 @@ static int runtoolcmd(lua_State *L, const char *tool_name)
     if (msg) {
       if (!strncmp(msg, "module ", 7))
 	msg = "unknown luaJIT command or tools not installed";
-      l_message(progname, msg);
+      l_message(msg);
     }
     return 1;
   }
@@ -567,7 +566,6 @@ static int pmain(lua_State *L)
   int argn;
   int flags = 0;
   globalL = L;
-  if (argv[0] && argv[0][0]) progname = argv[0];
 
   LUAJIT_VERSION_SYM();  /* Linker-enforced version check. */
 
@@ -623,9 +621,11 @@ static int pmain(lua_State *L)
 int main(int argc, char **argv)
 {
   int status;
-  lua_State *L = lua_open();
+  lua_State *L;
+  if (!argv[0]) argv = empty_argv; else if (argv[0][0]) progname = argv[0];
+  L = lua_open();  /* create state */
   if (L == NULL) {
-    l_message(argv[0], "cannot create state: not enough memory");
+    l_message("cannot create state: not enough memory");
     return EXIT_FAILURE;
   }
   smain.argc = argc;
diff --git a/test/tarantool-c-tests/CMakeLists.txt b/test/tarantool-c-tests/CMakeLists.txt
index c4a402d0..c84c651d 100644
--- a/test/tarantool-c-tests/CMakeLists.txt
+++ b/test/tarantool-c-tests/CMakeLists.txt
@@ -41,6 +41,14 @@ file(GLOB tests "${CMAKE_CURRENT_SOURCE_DIR}/*${CTEST_SRC_SUFFIX}")
 foreach(test_source ${tests})
   # Get test name without suffix. Needed to set OUTPUT_NAME.
   get_filename_component(exe ${test_source} NAME_WE)
+
+  # Test requires static build, since it inspects internal
+  # symbols.
+  if(exe STREQUAL "gh-8594-sysprof-ffunc-crash"
+      AND BUILDMODE STREQUAL "dynamic")
+    continue()
+  endif()
+
   add_executable(${exe} EXCLUDE_FROM_ALL ${test_source})
   target_include_directories(${exe} PRIVATE
     ${CMAKE_CURRENT_SOURCE_DIR}
diff --git a/test/tarantool-tests/CMakeLists.txt b/test/tarantool-tests/CMakeLists.txt
index c43b3d48..9bacac88 100644
--- a/test/tarantool-tests/CMakeLists.txt
+++ b/test/tarantool-tests/CMakeLists.txt
@@ -67,6 +67,10 @@ add_subdirectory(profilers/gh-5813-resolving-of-c-symbols/gnuhash)
 add_subdirectory(profilers/gh-5813-resolving-of-c-symbols/hash)
 add_subdirectory(profilers/gh-5813-resolving-of-c-symbols/stripped)
 
+if(BUILDMODE STREQUAL "dynamic")
+  add_subdirectory(fix-argv-handling)
+endif()
+
 # JIT, profiler, and bytecode toolchains are located in the <src/>
 # directory, <jit/vmdef.lua> is the autogenerated file also
 # located in the <src/> directory, but in the scope of the binary
@@ -99,6 +103,12 @@ if(LUAJIT_USE_VALGRIND)
   list(APPEND LUA_TEST_ENV_MORE LUAJIT_TEST_USE_VALGRIND=1)
 endif()
 
+# Needed to skip the <fix-argv-handling.test.lua> for a
+# non-dynamic build.
+if(BUILDMODE STREQUAL "dynamic")
+  list(APPEND LUA_TEST_ENV_MORE LUAJIT_BUILDMODE=dynamic)
+endif()
+
 set(TEST_SUITE_NAME "tarantool-tests")
 
 # XXX: The call produces both test and target
diff --git a/test/tarantool-tests/fix-argv-handling.test.lua b/test/tarantool-tests/fix-argv-handling.test.lua
new file mode 100644
index 00000000..84b626c3
--- /dev/null
+++ b/test/tarantool-tests/fix-argv-handling.test.lua
@@ -0,0 +1,26 @@
+local tap = require('tap')
+local test = tap.test('fix-argv-handling'):skipcond({
+  ['DYLD_INSERT_LIBRARIES does not work on macOS'] = jit.os == 'OSX',
+  ['Skipped for static build'] = os.getenv('LUAJIT_BUILDMODE') ~= 'dynamic',
+})
+
+test:plan(1)
+
+-- XXX: Since the Linux kernel 5.18-rc1 release, `argv` is forced
+-- to a single empty string if it is empty [1], so the issue is
+-- not reproducible on new kernels.
+--
+-- [1]: https://lore.kernel.org/all/20220201000947.2453721-1-keescook@chromium.org/
+
+local utils = require('utils')
+local execlib = require('execlib')
+local cmd = utils.exec.luabin(arg)
+
+-- Start the LuaJIT with an empty argv array and mocked
+-- `luaL_newstate`.
+local output = execlib.empty_argv_exec(cmd)
+
+-- Without the patch, the test fails with a segmentation fault
+-- instead of returning an error.
+test:like(output, 'cannot create state', 'correct argv handling')
+test:done(true)
diff --git a/test/tarantool-tests/fix-argv-handling/CMakeLists.txt b/test/tarantool-tests/fix-argv-handling/CMakeLists.txt
new file mode 100644
index 00000000..6b9bb4a6
--- /dev/null
+++ b/test/tarantool-tests/fix-argv-handling/CMakeLists.txt
@@ -0,0 +1,3 @@
+get_filename_component(test_name ${CMAKE_CURRENT_SOURCE_DIR} NAME)
+BuildTestCLib(mynewstate mynewstate.c ${test_name}.test.lua)
+BuildTestCLib(execlib execlib.c ${test_name}.test.lua)
diff --git a/test/tarantool-tests/fix-argv-handling/execlib.c b/test/tarantool-tests/fix-argv-handling/execlib.c
new file mode 100644
index 00000000..a8d5f16c
--- /dev/null
+++ b/test/tarantool-tests/fix-argv-handling/execlib.c
@@ -0,0 +1,67 @@
+#define _GNU_SOURCE
+#include "lua.h"
+#include "lauxlib.h"
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+/* 1Kb should be enough. */
+#define BUF_SIZE 1024
+#define CHECKED(call) \
+do { \
+	if ((call) == -1) { \
+		perror(#call); \
+		exit(1); \
+	} \
+} while(0)
+
+static int empty_argv_exec(struct lua_State *L)
+{
+	const char *path = luaL_checkstring(L, -1);
+	int pipefds[2] = {};
+	char *const argv[] = {NULL};
+	char buf[BUF_SIZE];
+
+	CHECKED(pipe2(pipefds, O_CLOEXEC));
+
+	pid_t pid = fork();
+	CHECKED(pid);
+
+	if (pid == 0) {
+		/*
+		 * Mock the `luaL_newstate` with an error-injected
+		 * version.
+		 */
+		setenv("LD_PRELOAD", "mynewstate.so", 1);
+		CHECKED(dup2(pipefds[1], STDOUT_FILENO));
+		CHECKED(dup2(pipefds[1], STDERR_FILENO));
+		/*
+		 * Pipes are closed on the exec call because of
+		 * the O_CLOEXEC flag.
+		 */
+		CHECKED(execvp(path, argv));
+	}
+
+	close(pipefds[1]);
+	CHECKED(waitpid(pid, NULL, 0));
+
+	CHECKED(read(pipefds[0], buf, BUF_SIZE));
+	close(pipefds[0]);
+
+	lua_pushstring(L, buf);
+	return 1;
+}
+
+static const struct luaL_Reg execlib[] = {
+	{"empty_argv_exec", empty_argv_exec},
+	{NULL, NULL}
+};
+
+LUA_API int luaopen_execlib(lua_State *L)
+{
+	luaL_register(L, "execlib", execlib);
+	return 1;
+}
diff --git a/test/tarantool-tests/fix-argv-handling/mynewstate.c b/test/tarantool-tests/fix-argv-handling/mynewstate.c
new file mode 100644
index 00000000..cf4a67e7
--- /dev/null
+++ b/test/tarantool-tests/fix-argv-handling/mynewstate.c
@@ -0,0 +1,9 @@
+#include <stddef.h>
+
+struct lua_State;
+
+/* Error-injected mock. */
+struct lua_State *luaL_newstate(void)
+{
+	return NULL;
+}
-- 
2.47.1

Re: [Tarantool-patches] [PATCH v3 luajit] Fix command-line argv handling.

[Sergey Bronnikov via Tarantool-patches]

[-- Attachment #1: Type: text/plain, Size: 828 bytes --]

Sergey,


thanks for the patch! LGTM with a minor comment.

Sergey

On 27.01.2025 13:18, Sergey Kaplun wrote:


<snipped>

> diff --git a/test/tarantool-c-tests/CMakeLists.txt b/test/tarantool-c-tests/CMakeLists.txt
> index c4a402d0..c84c651d 100644
> --- a/test/tarantool-c-tests/CMakeLists.txt
> +++ b/test/tarantool-c-tests/CMakeLists.txt
> @@ -41,6 +41,14 @@ file(GLOB tests "${CMAKE_CURRENT_SOURCE_DIR}/*${CTEST_SRC_SUFFIX}")
>   foreach(test_source ${tests})
>     # Get test name without suffix. Needed to set OUTPUT_NAME.
>     get_filename_component(exe ${test_source} NAME_WE)
> +
> +  # Test requires static build, since it inspects internal
> +  # symbols.
> +  if(exe STREQUAL "gh-8594-sysprof-ffunc-crash"
> +      AND BUILDMODE STREQUAL "dynamic")
please put AND to the previous line and fix indentation
<snipped>

[-- Attachment #2: Type: text/html, Size: 1530 bytes --]

Re: [Tarantool-patches] [PATCH v3 luajit] Fix command-line argv handling.

[Sergey Kaplun via Tarantool-patches]

Hi, Sergey!
Thanks for the review!
Fixed your comment and force-pushed the branch.

On 28.01.25, Sergey Bronnikov wrote:
> Sergey,
> 
> 
> thanks for the patch! LGTM with a minor comment.
> 
> Sergey
> 
> On 27.01.2025 13:18, Sergey Kaplun wrote:
> 
> 
> <snipped>
> 
> > diff --git a/test/tarantool-c-tests/CMakeLists.txt b/test/tarantool-c-tests/CMakeLists.txt
> > index c4a402d0..c84c651d 100644
> > --- a/test/tarantool-c-tests/CMakeLists.txt
> > +++ b/test/tarantool-c-tests/CMakeLists.txt
> > @@ -41,6 +41,14 @@ file(GLOB tests "${CMAKE_CURRENT_SOURCE_DIR}/*${CTEST_SRC_SUFFIX}")
> >   foreach(test_source ${tests})
> >     # Get test name without suffix. Needed to set OUTPUT_NAME.
> >     get_filename_component(exe ${test_source} NAME_WE)
> > +
> > +  # Test requires static build, since it inspects internal
> > +  # symbols.
> > +  if(exe STREQUAL "gh-8594-sysprof-ffunc-crash"
> > +      AND BUILDMODE STREQUAL "dynamic")
> please put AND to the previous line and fix indentation
> <snipped>

Fixed, thanks!

===================================================================
diff --git a/test/tarantool-c-tests/CMakeLists.txt b/test/tarantool-c-tests/CMakeLists.txt
index c84c651d..32a8add0 100644
--- a/test/tarantool-c-tests/CMakeLists.txt
+++ b/test/tarantool-c-tests/CMakeLists.txt
@@ -44,8 +44,8 @@ foreach(test_source ${tests})
 
   # Test requires static build, since it inspects internal
   # symbols.
-  if(exe STREQUAL "gh-8594-sysprof-ffunc-crash"
-      AND BUILDMODE STREQUAL "dynamic")
+  if(exe STREQUAL "gh-8594-sysprof-ffunc-crash" AND
+     BUILDMODE STREQUAL "dynamic")
     continue()
   endif()
 
===================================================================


-- 
Best regards,
Sergey Kaplun

Re: [Tarantool-patches] [PATCH v3 luajit] Fix command-line argv handling.

[Sergey Kaplun via Tarantool-patches]

I've applied the patch into all long-term branches in tarantool/luajit
and bumped a new version in master [1], release/3.3 [2], release/3.2 [3]
and release/2.11 [4].

[1]: https://github.com/tarantool/tarantool/pull/11063
[2]: https://github.com/tarantool/tarantool/pull/11064
[3]: https://github.com/tarantool/tarantool/pull/11065
[4]: https://github.com/tarantool/tarantool/pull/11066

-- 
Best regards,
Sergey Kaplun