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Add memory allocation failure checks.

This commit is contained in:
Andrius Štikonas 2024-01-01 12:28:29 +00:00
parent a870103aad
commit 008899d565
Signed by: andrius
GPG Key ID: 0C0331D5228A3B62
2 changed files with 31 additions and 8 deletions
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2
M2libc

@ -1 +1 @@
Subproject commit ff47b1cca5fc6f7591b8572710eabf73198e2de2
Subproject commit c8090241c55fe23033c674c47da6c3719e5bca3a

37
posix-runner/posix-runner.c
View File

@ -16,9 +16,7 @@
void* syscall_table;
#define MAX_PROC 16
#define MAX_MIB_PER_PROC 128
#define MAX_SAVED_MIB 1024
struct mem_block {
void* address;
@ -49,7 +47,7 @@ void* _get_stack()
void* get_stack()
{
/* Adjust to stack depth of _get_stack function */
return _get_stack() + (7 * sizeof(void*));
return _get_stack() + (7 * sizeof(void *));
}
int extract_field(char* file_data, int position, int length)
@ -63,6 +61,10 @@ int load_elf(FILE* file_in, struct process* current)
{
int file_size = fseek(file_in, 0, SEEK_END);
char* file_data = calloc(1, file_size + 0x1000); /* Allocate extra space in case application tries to use it */
if (file_data == NULL) {
fputs("Could not allocate memory to load ELF file.", stderr);
exit(1);
}
rewind(file_in);
fread(file_data, 1, file_size, file_in);
fclose(file_in);
@ -138,6 +140,7 @@ int sys_brk(void* addr, void, void, void, void, void)
if (current_process->brk == NULL) {
current_process->brk = calloc(1, MAX_MIB_PER_PROC * 1024 * 1024);
if (current_process->brk == NULL) {
fputs("Could not allocate memory for brk region.", stderr);
return addr;
}
current_process->memory = current_process->brk;
@ -163,9 +166,17 @@ int sys_fork(void, void, void, void, void, void)
current_process->forked = TRUE;
current_process->saved_stack.length = current_process->stack - current_process->saved_stack_pointer;
current_process->saved_stack.address = malloc(current_process->saved_stack.length);
if (current_process->saved_stack.address == NULL ) {
fputs("Could not allocate memory for saved process stack.", stderr);
exit(1);
}
memcpy(current_process->saved_stack.address, current_process->saved_stack_pointer, current_process->saved_stack.length);
current_process->saved_memory.length = current_process->brk - current_process->memory;
current_process->saved_memory.address = malloc(current_process->saved_memory.length);
if (current_process->saved_stack.address == NULL ) {
fputs("Could not allocate memory for saved process memory.", stderr);
exit(1);
}
memcpy(current_process->saved_memory.address, current_process->memory, current_process->saved_memory.length);
return 0; /* return as child */
@ -174,7 +185,11 @@ int sys_fork(void, void, void, void, void, void)
int sys_execve(char* file_name, char** argv, char** envp, void, void, void)
{
if (current_process->forked) {
struct process* new = calloc(1, sizeof(process));
struct process* new = calloc(1, sizeof(struct process));
if (new == NULL) {
fputs("Could not allocate memory for new process metadata.", stderr);
exit(1);
}
new->parent = current_process;
current_process->forked = FALSE; /* fork was handled */
current_process = new;
@ -211,8 +226,8 @@ void sys_exit(unsigned value, void, void, void, void, void)
memcpy(current_process->saved_stack_pointer, current_process->saved_stack.address, current_process->saved_stack.length);
memcpy(current_process->memory, current_process->saved_memory.address, current_process->saved_memory.length);
free(current_process->saved_stack);
free(current_process->saved_memory);
free(current_process->saved_stack.address);
free(current_process->saved_memory.address);
current_process->brk = current_process->saved_brk;
current_process->saved_stack_pointer;
/* Simulate return from sys_fork() */
@ -266,6 +281,10 @@ int sys_chroot(char const *path)
void init_syscalls()
{
syscall_table = calloc(300, sizeof(void *));
if (syscall_table == NULL) {
fputs("Could not allocate memory for syscall table.", stderr);
exit(1);
}
syscall_table[0] = sys_read;
syscall_table[1] = sys_write;
syscall_table[2] = sys_open;
@ -316,7 +335,7 @@ ulong rdmsrl(unsigned msr)
void _entry_syscall(long syscall, long arg1, long arg2, long arg3, long arg4, long arg5, long arg6)
{
FUNCTION process_syscall = syscall_table[syscall];
if(process_syscall != NULL) {
if (process_syscall != NULL) {
return process_syscall(arg1, arg2, arg3, arg4, arg5, arg6);
}
/* Unsupported syscall */
@ -386,6 +405,10 @@ int main(int argc, char** argv, char** envp)
}
current_process = calloc(1, sizeof(process));
if (current_process == NULL) {
fputs("Could not allocate memory for current process metadata.", stderr);
exit(1);
}
/* Load binary into memory */
int rval = load_elf(file_in, current_process);