minix/lib/libexec/exec_general.c

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#define _SYSTEM 1
#include <minix/type.h>
#include <minix/const.h>
#include <sys/param.h>
#include <assert.h>
#include <unistd.h>
#include <errno.h>
#include <libexec.h>
#include <string.h>
#include <assert.h>
#include <minix/ipc.h>
#include <minix/com.h>
#include <minix/callnr.h>
#include <machine/elf.h>
void libexec_patch_ptr(char stack[ARG_MAX], vir_bytes base)
{
/* When doing an exec(name, argv, envp) call, the user builds up a stack
* image with arg and env pointers relative to the start of the stack. Now
* these pointers must be relocated, since the stack is not positioned at
* address 0 in the user's address space.
*/
char **ap, flag;
vir_bytes v;
flag = 0; /* counts number of 0-pointers seen */
ap = (char **) stack; /* points initially to 'nargs' */
ap++; /* now points to argv[0] */
while (flag < 2) {
if (ap >= (char **) &stack[ARG_MAX]) return; /* too bad */
if (*ap != NULL) {
v = (vir_bytes) *ap; /* v is relative pointer */
v += base; /* relocate it */
*ap = (char *) v; /* put it back */
} else {
flag++;
}
ap++;
}
}
int libexec_pm_newexec(endpoint_t proc_e, struct exec_info *e)
{
int r;
message m;
m.m_type = PM_NEWEXEC;
m.EXC_NM_PROC = proc_e;
m.EXC_NM_PTR = (char *)e;
if ((r = sendrec(PM_PROC_NR, &m)) != OK) return(r);
e->allow_setuid = !!(m.m1_i2 & EXC_NM_RF_ALLOW_SETUID);
return(m.m_type);
}