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execve():

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- COKERNEL_PATH and COKERNEL_EXEC_ROOT support for co-kernels with different architecture than the host (i.e., Xeon Phi).
- fix various error codes: ENAMETOOLONG, ENOENT, ENOTDIR, EACCES, ENOEXEC, EFAULT.
- support for shell code execution.
This commit is contained in:
Balazs Gerofi bgerofi@riken.jp
2014-09-03 18:15:43 +09:00
parent 308987c1ee
commit cd366de097
6 changed files with 224 additions and 92 deletions
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3
executer/include/uprotocol.h
View File

@ -63,6 +63,8 @@ struct program_image_section {
void *fp;
};
#define SHELL_PATH_MAX_LEN 1024
struct program_load_desc {
int num_sections;
int status;
@ -88,6 +90,7 @@ struct program_load_desc {
unsigned long rlimit_stack_cur;
unsigned long rlimit_stack_max;
unsigned long interp_align;
char shell_path[SHELL_PATH_MAX_LEN];
struct program_image_section sections[0];
};

278
executer/user/mcexec.c
View File

@ -338,14 +338,109 @@ struct program_load_desc *load_interp(struct program_load_desc *desc0, FILE *fp)
unsigned char *dma_buf;
int load_elf_desc(char *filename, struct program_load_desc **desc_p)
int lookup_exec_path(char *filename, char *path, int max_len)
{
int found = 0;
int error;
/* Is file not absolute path? */
if (strncmp(filename, "/", 1)) {
/* Is filename a single component without path? */
if (strncmp(filename, ".", 1) && !strchr(filename, '/')) {
char *token, *string, *tofree;
char *PATH = getenv("COKERNEL_PATH");
if (!PATH) {
PATH = getenv("PATH");
}
if (strlen(filename) >= 255) {
return ENAMETOOLONG;
}
__dprintf("PATH: %s\n", PATH);
/* strsep() modifies string! */
tofree = string = strdup(PATH);
if (string == NULL) {
printf("lookup_exec_path(): copying PATH, not enough memory?\n");
return ENOMEM;
}
while ((token = strsep(&string, ":")) != NULL) {
error = snprintf(path, max_len,
"%s/%s", token, filename);
if (error < 0 || error >= max_len) {
fprintf(stderr, "lookup_exec_path(): array too small?\n");
continue;
}
error = access(path, X_OK);
if (error == 0) {
found = 1;
break;
}
}
free(tofree);
}
/* Not in path, file to be open from the working directory */
if (!found) {
error = snprintf(path, max_len, "%s", filename);
if (error < 0 || error >= max_len) {
fprintf(stderr, "lookup_exec_path(): array too small?\n");
return ENOMEM;
}
found = 1;
}
}
/* Absolute path */
else if (!strncmp(filename, "/", 1)) {
char *root = getenv("COKERNEL_EXEC_ROOT");
if (root) {
error = snprintf(path, max_len, "%s/%s", root, filename);
}
else {
error = snprintf(path, max_len, "%s", filename);
}
if (error < 0 || error >= max_len) {
fprintf(stderr, "lookup_exec_path(): array too small?\n");
return ENOMEM;
}
found = 1;
}
if (!found) {
fprintf(stderr,
"lookup_exec_path(): error finding file %s\n", filename);
return ENOENT;
}
__dprintf("lookup_exec_path(): %s\n", path);
return 0;
}
int load_elf_desc(char *filename, struct program_load_desc **desc_p,
char **shell_p)
{
FILE *fp;
FILE *interp = NULL;
char *interp_path;
char *shell = NULL;
size_t shell_len = 0;
struct program_load_desc *desc;
int ret = 0;
struct stat sb;
char header[1024];
if ((ret = access(filename, X_OK)) != 0) {
fprintf(stderr, "Error: %s is not an executable?, errno: %d\n",
@ -369,6 +464,27 @@ int load_elf_desc(char *filename, struct program_load_desc **desc_p)
return errno;
}
if (fread(&header, 1, 2, fp) != 2) {
fprintf(stderr, "Error: Failed to read header from %s\n", filename);
return errno;
}
if (!strncmp(header, "#!", 2)) {
if (getline(&shell, &shell_len, fp) == -1) {
fprintf(stderr, "Error: reading shell path %s\n", filename);
}
fclose(fp);
/* Delete new line character */
shell[strlen(shell) - 1] = 0;
*shell_p = shell;
return 0;
}
rewind(fp);
desc = load_elf(fp, &interp_path);
if (!desc) {
fclose(fp);
@ -519,7 +635,7 @@ void print_flat(char *flat)
* returns the total length of the flat string and updates flat to
* point to the beginning.
*/
int flatten_strings(int nr_strings, char **strings, char **flat)
int flatten_strings(int nr_strings, char *first, char **strings, char **flat)
{
int full_len, string_i;
unsigned long flat_offset;
@ -532,6 +648,10 @@ int flatten_strings(int nr_strings, char **strings, char **flat)
/* Count full length */
full_len = sizeof(int) + sizeof(char *); // Counter and terminating NULL
if (first) {
full_len += sizeof(char *) + strlen(first) + 1;
}
for (string_i = 0; string_i < nr_strings; ++string_i) {
// Pointer + actual value
full_len += sizeof(char *) + strlen(strings[string_i]) + 1;
@ -545,18 +665,25 @@ int flatten_strings(int nr_strings, char **strings, char **flat)
memset(_flat, 0, full_len);
/* Number of strings */
*((int*)_flat) = nr_strings;
*((int*)_flat) = nr_strings + (first ? 1 : 0);
// Actual offset
flat_offset = sizeof(int) + sizeof(char *) * (nr_strings + 1);
flat_offset = sizeof(int) + sizeof(char *) * (nr_strings + 1 +
(first ? 1 : 0));
if (first) {
*((char **)(_flat + sizeof(int))) = (void *)flat_offset;
memcpy(_flat + flat_offset, first, strlen(first) + 1);
flat_offset += strlen(first) + 1;
}
for (string_i = 0; string_i < nr_strings; ++string_i) {
/* Fabricate the string */
*((char **)(_flat + sizeof(int) + string_i * sizeof(char *))) = (void *)flat_offset;
*((char **)(_flat + sizeof(int) + (string_i + (first ? 1 : 0))
* sizeof(char *))) = (void *)flat_offset;
memcpy(_flat + flat_offset, strings[string_i], strlen(strings[string_i]) + 1);
flat_offset += strlen(strings[string_i]) + 1;
}
*flat = _flat;
@ -756,6 +883,9 @@ int main(int argc, char **argv)
int target_core = 0;
int mcosid = 0;
int opt;
char path[1024];
char *shell = NULL;
char shell_path[1024];
#ifdef USE_SYSCALL_MOD_CALL
__glob_argc = argc;
@ -768,7 +898,7 @@ int main(int argc, char **argv)
}
/* Collect environment variables */
envs_len = flatten_strings(-1, environ, &envs);
envs_len = flatten_strings(-1, NULL, environ, &envs);
envs = envs;
error = getrlimit(RLIMIT_STACK, &rlim_stack);
@ -820,18 +950,40 @@ int main(int argc, char **argv)
for (i = optind; i < argc; ++i) {
__dprintf("%s ", argv[i]);
}
__dprintf("\n");
__dprintf("%s", "\n");
if (load_elf_desc(argv[optind], &desc) != 0) {
if (lookup_exec_path(argv[optind], path, sizeof(path)) != 0) {
fprintf(stderr, "error: finding file: %s\n", argv[optind]);
return 1;
}
if (load_elf_desc(path, &desc, &shell) != 0) {
fprintf(stderr, "error: loading file: %s\n", argv[optind]);
return 1;
}
/* Check whether shell script */
if (shell) {
if (lookup_exec_path(shell, shell_path, sizeof(shell_path)) != 0) {
fprintf(stderr, "error: finding file: %s\n", shell);
return 1;
}
if (load_elf_desc(shell_path, &desc, &shell) != 0) {
fprintf(stderr, "error: loading file: %s\n", shell);
return 1;
}
}
if (shell) {
argv[optind] = path;
}
desc->envs_len = envs_len;
desc->envs = envs;
//print_flat(envs);
desc->args_len = flatten_strings(-1, argv + optind, &args);
desc->args_len = flatten_strings(-1, shell, argv + optind, &args);
desc->args = args;
//print_flat(args);
@ -1269,93 +1421,51 @@ int main_loop(int fd, int cpu, pthread_mutex_t *lock)
switch (w.sr.args[0]) {
struct program_load_desc *desc;
struct remote_transfer trans;
int error;
int found;
char path[2048];
char path[1024];
char *filename;
int ret;
char *shell = NULL;
char shell_path[1024];
/* Load descriptor phase */
case 1:
ret = -1;
found = 0;
filename = (char *)w.sr.args[1];
/* Is filename a single component without path? */
if (strncmp(filename, "/", 1)
&& !strchr(filename, '/')) {
char *token, *string, *tofree;
char *PATH = getenv("COKERNEL_PATH");
if (!PATH) {
PATH = getenv("PATH");
}
if (strlen(filename) >= 255) {
ret = ENAMETOOLONG;
goto return_execve1;
}
__dprintf("PATH: %s\n", PATH);
/* strsep() modifies string! */
tofree = string = strdup(PATH);
if (string == NULL) {
printf("error: copying PATH, not enough memory?\n");
goto return_execve1;
}
while ((token = strsep(&string, ":")) != NULL) {
error = snprintf(path, sizeof(path),
"%s/%s", token, filename);
if (error < 0 || error >= sizeof(path)) {
fprintf(stderr, "execve(): array too small?\n");
continue;
}
error = access(path, X_OK);
if (error == 0) {
found = 1;
break;
}
}
free(tofree);
}
else {
char *root = getenv("COKERNEL_EXEC_ROOT");
if (root) {
error = snprintf(path, sizeof(path), "%s/%s", root, filename);
}
else {
error = snprintf(path, sizeof(path), "%s", filename);
}
if (error < 0 || error >= sizeof(path)) {
fprintf(stderr, "execve(): array too small?\n");
goto return_execve1;
}
found = 1;
}
if (!found) {
fprintf(stderr,
"execve(): error finding file %s\n", filename);
ret = ENOENT;
if ((ret = lookup_exec_path(filename, path, sizeof(path)))
!= 0) {
goto return_execve1;
}
__dprintf("execve(): path to binary: %s\n", path);
if ((ret = load_elf_desc(path, &desc)) != 0) {
if ((ret = load_elf_desc(path, &desc, &shell)) != 0) {
fprintf(stderr,
"execve(): error loading ELF for file %s\n", path);
goto return_execve1;
}
/* Check whether shell script */
if (shell) {
if ((ret = lookup_exec_path(shell, shell_path,
sizeof(shell_path))) != 0) {
fprintf(stderr, "execve(): error: finding file: %s\n", shell);
goto return_execve1;
}
if ((ret = load_elf_desc(shell_path, &desc, &shell))
!= 0) {
fprintf(stderr, "execve(): error: loading file: %s\n", shell);
goto return_execve1;
}
if (strlen(shell_path) >= SHELL_PATH_MAX_LEN) {
fprintf(stderr, "execve(): error: shell path too long: %s\n", shell_path);
ret = ENAMETOOLONG;
goto return_execve1;
}
/* Let the LWK know the shell interpreter */
strcpy(desc->shell_path, shell_path);
}
__dprintf("execve(): load_elf_desc() for %s OK, num sections: %d\n",
path, desc->num_sections);
@ -1410,10 +1520,10 @@ return_execve1:
goto return_execve1;
}
__dprintf("execve(): transfer ELF desc OK\n");
__dprintf("%s", "execve(): transfer ELF desc OK\n");
transfer_image(fd, desc);
__dprintf("execve(): image transferred\n");
__dprintf("%s", "execve(): image transferred\n");
ret = 0;
return_execve2: