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/* execve() - basic program execution call */
#include <sys/cdefs.h>
#include "namespace.h"
#include <lib.h>
#include <unistd.h>
#include <string.h>
#include <stddef.h>
#include <minix/param.h>
#include <sys/exec_elf.h>
#include <sys/exec.h>
int execve(const char *path, char * const *argv, char * const *envp)
{
message m;
size_t frame_size = 0; /* Size of the new initial stack. */
int argc = 0; /* Argument count. */
int envc = 0; /* Environment count */
char overflow = 0; /* No overflow yet. */
char *frame;
struct ps_strings *psp;
int vsp = 0; /* (virtual) Stack pointer in new address space. */
minix_stack_params(path, argv, envp, &frame_size, &overflow,
&argc, &envc);
/* The party is off if there is an overflow. */
if (overflow) {
errno = E2BIG;
return -1;
}
/* Allocate space for the stack frame. */
if ((frame = (char *) sbrk(frame_size)) == (char *) -1) {
errno = E2BIG;
return -1;
}
minix_stack_fill(path, argc, argv, envc, envp, frame_size, frame,
&vsp, &psp);
/* Clear unused message fields */
memset(&m, 0, sizeof(m));
/* We can finally make the system call. */
m.m_lc_pm_exec.name = (vir_bytes)path;
m.m_lc_pm_exec.namelen = strlen(path) + 1;
m.m_lc_pm_exec.frame = (vir_bytes)frame;
m.m_lc_pm_exec.framelen = frame_size;
m.m_lc_pm_exec.ps_str = (vir_bytes)(vsp + ((char *)psp - frame));
(void) _syscall(PM_PROC_NR, PM_EXEC, &m);
/* Failure, return the memory used for the frame and exit. */
(void) sbrk(-frame_size);
return -1;
}
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