1 /* execve() - basic program execution call */
2
3 #include <sys/cdefs.h>
4 #include "namespace.h"
5 #include <lib.h>
6
7 #include <unistd.h>
8 #include <string.h>
9 #include <stddef.h>
10 #include <minix/param.h>
11 #include <sys/exec_elf.h>
12 #include <sys/exec.h>
13
execve(const char * path,char * const * argv,char * const * envp)14 int execve(const char *path, char * const *argv, char * const *envp)
15 {
16 message m;
17 size_t frame_size = 0; /* Size of the new initial stack. */
18 int argc = 0; /* Argument count. */
19 int envc = 0; /* Environment count */
20 char overflow = 0; /* No overflow yet. */
21 char *frame;
22 struct ps_strings *psp;
23 int vsp = 0; /* (virtual) Stack pointer in new address space. */
24
25 minix_stack_params(path, argv, envp, &frame_size, &overflow,
26 &argc, &envc);
27
28 /* The party is off if there is an overflow. */
29 if (overflow) {
30 errno = E2BIG;
31 return -1;
32 }
33
34 /* Allocate space for the stack frame. */
35 if ((frame = (char *) sbrk(frame_size)) == (char *) -1) {
36 errno = E2BIG;
37 return -1;
38 }
39
40 minix_stack_fill(path, argc, argv, envc, envp, frame_size, frame,
41 &vsp, &psp);
42
43 /* Clear unused message fields */
44 memset(&m, 0, sizeof(m));
45
46 /* We can finally make the system call. */
47 m.m_lc_pm_exec.name = (vir_bytes)path;
48 m.m_lc_pm_exec.namelen = strlen(path) + 1;
49 m.m_lc_pm_exec.frame = (vir_bytes)frame;
50 m.m_lc_pm_exec.framelen = frame_size;
51 m.m_lc_pm_exec.ps_str = (vir_bytes)(vsp + ((char *)psp - frame));
52
53 (void) _syscall(PM_PROC_NR, PM_EXEC, &m);
54
55 /* Failure, return the memory used for the frame and exit. */
56 (void) sbrk(-frame_size);
57
58 return -1;
59 }
60