Re-enable Lua tests

* Add `environ` support to pass Lua tests
* Add `simple_environ` test to check `environ` support implementation
* Re-enable `lua_simple` and `lua_script`, which now pass

include/compartment.h

@@ -180,6 +180,10 @@ struct Compartment
     void *mem_top;
     bool mapped;
 
+    // Environ
+    char **environ_ptr;
+    size_t environ_sz;
+
     // Scratch memory
     void *scratch_mem_base;
     size_t scratch_mem_size;

src/comp_utils.c

@@ -68,6 +68,12 @@ realloc(void *to_realloc, size_t new_size)
     return new_alloc;
 }
 
+void *
+reallocarray(void *to_realloc, size_t elem_count, size_t elem_size)
+{
+    return realloc(to_realloc, elem_count * elem_size);
+}
+
 void
 tls_lookup_stub()
 {

src/compartment.c

@@ -4,6 +4,10 @@ const char *libs_path_env_var = "COMP_LIBRARY_PATH";
 const char *tls_rtld_dropin = "tls_lookup_stub";
 const char *comp_utils_soname = "libcomputils.so";
 
+extern char **proc_env_ptr;
+extern const size_t max_env_sz;
+extern const unsigned short max_env_count;
+
 /*******************************************************************************
  * Forward declarations
  ******************************************************************************/
@@ -34,6 +38,10 @@ find_in_dir(const char *, char *);
 static void
 init_comp_scratch_mem(struct Compartment *);
 static void
+adjust_comp_scratch_mem(struct Compartment *, size_t);
+static void
+setup_environ(struct Compartment *);
+static void
 resolve_comp_tls_regions(struct Compartment *);
 
 static void
@@ -157,6 +165,7 @@ comp_from_elf(char *filename, char **entry_points, size_t entry_point_count,
     assert(entry_point_count > 0);
 
     init_comp_scratch_mem(new_comp);
+    setup_environ(new_comp);
     find_comp_entry_points(entry_points, entry_point_count, new_comp);
     resolve_rela_syms(new_comp);
     resolve_comp_tls_regions(new_comp);
@@ -223,6 +232,27 @@ comp_map(struct Compartment *to_map)
         err(1, "Error mapping compartment %zu scratch memory", to_map->id);
     }
 
+    /* Copy over environ variables
+    //
+    // We need a pointer to an array of string pointers, so we synthetically
+    // create one. We don't expect this pointer to move, as the maximum allowed
+    // size for the `environ` array is already allocated
+    */
+    *to_map->environ_ptr = (char *) (to_map->environ_ptr + 1);
+    to_map->environ_ptr += 1;
+
+    // Copy over prepared `environ` data from manager
+    memcpy(to_map->environ_ptr, proc_env_ptr, max_env_sz);
+    for (unsigned short i = 0; i < max_env_count; ++i)
+    {
+        if (*(to_map->environ_ptr + i) == 0x0)
+        {
+            break;
+        }
+        // Update entry offsets relative to compartment address
+        *(to_map->environ_ptr + i) += (uintptr_t) to_map->environ_ptr;
+    }
+
     size_t tls_allocd = 0x0;
     for (size_t i = 0; i < to_map->libs_count; ++i)
     {
@@ -758,17 +788,7 @@ parse_lib_rela(Elf64_Shdr *rela_shdr, Elf64_Ehdr *lib_ehdr, int lib_fd,
 
                 // Filter out some `libc` symbols we don't want to handle
                 // TODO at least right now
-                if (!strcmp(&dyn_str_tbl[curr_rela_sym.st_name], "environ"))
-                {
-                    warnx("Currently not relocating symbol `environ` from "
-                          "library "
-                          "%s - "
-                          "using within a container might cause a crash.",
-                        lib_dep->lib_name);
-                    continue;
-                }
-                else if (!strcmp(
-                             &dyn_str_tbl[curr_rela_sym.st_name], "__progname"))
+                if (!strcmp(&dyn_str_tbl[curr_rela_sym.st_name], "__progname"))
                 {
                     warnx("Currently not relocating symbol `__progname` from "
                           "library %s "
@@ -900,6 +920,13 @@ resolve_rela_syms(struct Compartment *new_comp)
                 continue;
             }
 
+            if (curr_rela_map->rela_name
+                && !strcmp(curr_rela_map->rela_name, "environ"))
+            {
+                curr_rela_map->target_func_address = new_comp->environ_ptr;
+                continue;
+            }
+
             struct LibSymSearchResult found_sym
                 = find_lib_dep_sym_in_comp(curr_rela_map->rela_name, new_comp,
                     curr_rela_map->rela_sym_type);
@@ -1061,6 +1088,23 @@ init_comp_scratch_mem(struct Compartment *new_comp)
     assert(new_comp->scratch_mem_size % 16 == 0);
 }
 
+static void
+adjust_comp_scratch_mem(struct Compartment *new_comp, size_t to_adjust)
+{
+    new_comp->scratch_mem_size += to_adjust;
+    new_comp->mem_top = (char *) new_comp->mem_top + to_adjust;
+}
+
+static void
+setup_environ(struct Compartment *new_comp)
+{
+    assert(proc_env_ptr != NULL); // TODO consider optional check
+    new_comp->environ_sz
+        = align_up(max_env_sz, new_comp->page_size) + new_comp->page_size;
+    new_comp->environ_ptr = new_comp->mem_top;
+    adjust_comp_scratch_mem(new_comp, new_comp->environ_sz);
+}
+
 static void
 resolve_comp_tls_regions(struct Compartment *new_comp)
 {
@@ -1072,7 +1116,7 @@ resolve_comp_tls_regions(struct Compartment *new_comp)
 
     // TODO currently we only support one thread
     new_comp->libs_tls_sects->region_count = 1;
-    new_comp->libs_tls_sects->region_start = new_comp->scratch_mem_stack_top;
+    new_comp->libs_tls_sects->region_start = new_comp->mem_top;
     new_comp->libs_tls_sects->libs_count = 0;
 
     unsigned short *lib_idxs
@@ -1098,8 +1142,7 @@ resolve_comp_tls_regions(struct Compartment *new_comp)
 
     intptr_t total_tls_size
         = comp_tls_size * new_comp->libs_tls_sects->region_count;
-    new_comp->scratch_mem_size += total_tls_size;
-    new_comp->mem_top = (char *) new_comp->mem_top + total_tls_size;
+    adjust_comp_scratch_mem(new_comp, total_tls_size);
     new_comp->libs_tls_sects->region_size = comp_tls_size;
 
     assert((uintptr_t) new_comp->libs_tls_sects->region_start % 16 == 0);

src/manager.c

@@ -15,12 +15,21 @@ void *__capability manager_ddc = 0;
 
 const char *comp_config_suffix = ".comp";
 
+char **proc_env_ptr = NULL;
+const unsigned short avg_sz_per_env_entry = 128; // TODO
+const unsigned short max_env_count = 128; // TODO
+const size_t max_env_sz
+    = max_env_count * sizeof(char *) + avg_sz_per_env_entry * max_env_count;
+extern char **environ;
+
 static struct CompEntryPointDef *
 parse_compartment_config(char *, size_t *, bool);
 static struct CompEntryPointDef *
 make_default_entry_point();
 static struct CompEntryPointDef
 get_entry_point(char *, struct CompEntryPointDef *, size_t);
+static void
+prepare_compartment_environ();
 static void *
 prepare_compartment_args(char **args, struct CompEntryPointDef);
 
@@ -78,6 +87,11 @@ get_next_comp_addr(void)
 struct Compartment *
 register_new_comp(char *filename, bool allow_default_entry)
 {
+    if (!proc_env_ptr)
+    {
+        prepare_compartment_environ();
+    }
+
     size_t new_comp_ep_count;
     struct CompEntryPointDef *new_cep = parse_compartment_config(
         filename, &new_comp_ep_count, allow_default_entry);
@@ -145,6 +159,9 @@ clean_all_comps()
         clean_comp(comps[i]->comp);
     }
     free(comps);
+
+    free(proc_env_ptr);
+    proc_env_ptr = NULL;
 }
 
 void
@@ -324,6 +341,28 @@ get_entry_point(
     errx(1, "Did not find entry point for function %s!\n", entry_point_fn);
 }
 
+static void
+prepare_compartment_environ()
+{
+    proc_env_ptr = malloc(max_env_sz);
+    memset(proc_env_ptr, 0, max_env_sz);
+    char **prov_env_vals = proc_env_ptr + max_env_count * sizeof(char *);
+
+    size_t envs_parsed = 0;
+    size_t envs_parsed_sz = 0;
+    const uintptr_t vals_offset = max_env_count * sizeof(char *);
+    for (char **curr_env = environ; *curr_env; curr_env++)
+    {
+        // We only save offsets for the pointers, since they'll be relocated
+        // relative to the compartment base address
+        proc_env_ptr[envs_parsed] = (char *) (vals_offset + envs_parsed_sz);
+        strcpy((char *) proc_env_ptr + vals_offset + envs_parsed_sz, *curr_env);
+
+        envs_parsed += 1;
+        envs_parsed_sz += strlen(*curr_env) + 1;
+    }
+}
+
 static void *
 prepare_compartment_args(char **args, struct CompEntryPointDef cep)
 {

tests/CMakeLists.txt

@@ -124,6 +124,7 @@ set(comp_binaries
     "simple_call_internal"
     "simple_call_internal_static"
     "simple_call_internal_weak"
+    "simple_environ"
     "simple_external"
     "simple_fopen"
     "simple_fputs"
@@ -142,8 +143,8 @@ set(comp_binaries
     "simple_time"
     "simple_va_args"
 
-    #"lua_simple"
-    #"lua_script"
+    "lua_simple"
+    "lua_script"
 
     "args_simple"
     #"test_two_comps-comp1"
@@ -156,6 +157,7 @@ set(tests
     "simple_call_internal"
     "simple_call_internal_static"
     "simple_call_internal_weak"
+    "simple_environ"
     "simple_fopen"
     "simple_fputs"
     "simple_global_var"
@@ -170,8 +172,8 @@ set(tests
     "simple_time"
     "simple_va_args"
 
-    #"lua_simple"
-    #"lua_script"
+    "lua_simple"
+    "lua_script"
 
     "test_map"
     #"test_args_near_unmapped"
@@ -217,9 +219,9 @@ new_dependency(simple_global_var $<TARGET_FILE:simple_global_var-external>)
 target_link_libraries(simple_thrloc_var PRIVATE simple_thrloc_var-external)
 new_dependency(simple_thrloc_var $<TARGET_FILE:simple_thrloc_var-external>)
 
-#new_dependency(test_map $<TARGET_FILE:simple>)
+new_dependency(test_map $<TARGET_FILE:simple>)
 
-#new_dependency(lua_script ${CMAKE_CURRENT_SOURCE_DIR}/hello_world.lua)
+new_dependency(lua_script ${CMAKE_CURRENT_SOURCE_DIR}/hello_world.lua)
 #new_dependency(test_args_near_unmapped $<TARGET_FILE:args_simple>)
 #new_dependency(test_args_near_unmapped ${CMAKE_CURRENT_SOURCE_DIR}/args_simple.comp)
 

tests/lua_script.c

@@ -42,7 +42,7 @@ do_script()
 }
 
 int
-main(int argc, char **argv)
+main()
 {
     do_script_arg("./hello_world.lua");
     return 0;

tests/lua_simple.c

@@ -15,5 +15,5 @@ main(void)
     lua_Integer len = luaL_len(L, 1);
 
     lua_close(L);
-    return (len == strlen(test_string) ? 0 : 1);
+    return ((unsigned long) len == strlen(test_string) ? 0 : 1);
 }

tests/simple_environ.c

@@ -0,0 +1,45 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+extern char **environ;
+
+int
+main()
+{
+    size_t i = 0;
+    for (char **curr_env = environ; *curr_env; ++curr_env)
+    {
+        printf("ENV -- %s\n", *curr_env);
+        ++i;
+    }
+    printf("---- COUNT - %zu\n", i);
+
+    char *lang = getenv("LANG");
+    assert(lang);
+    printf("getenv -- environ['LANG'] == %s\n", lang);
+
+    char *term = getenv("TERM");
+    assert(term);
+    printf("getenv -- environ['TERM'] == %s\n", term);
+
+    char *no = getenv("DOESNTEXIST");
+    assert(no == NULL);
+
+    const char *set_name = "TRYENV";
+    const char *set_val = "Hello Env";
+    int set_check = setenv(set_name, set_val, 1);
+    assert(set_check == 0);
+    char *set_get = getenv(set_name);
+    printf("setenv -- environ['%s'] == %s\n", set_name, set_get);
+    assert(!strcmp(set_get, set_val));
+
+    set_check = putenv("TRYENV=Goodbye Env");
+    assert(set_check == 0);
+    set_get = getenv(set_name);
+    printf("putenv -- environ['%s'] == %s\n", set_name, set_get);
+    assert(!strcmp(set_get, "Goodbye Env"));
+
+    return 0;
+}