1 #include "inc.h" 2 #include <assert.h> 3 #include <sys/exec.h> 4 #include <libexec.h> 5 #include <machine/vmparam.h> 6 7 static int do_exec(int proc_e, char *exec, size_t exec_len, char *progname, 8 char *frame, int frame_len, vir_bytes ps_str); 9 static int exec_restart(int proc_e, int result, vir_bytes pc, vir_bytes ps_str); 10 static int read_seg(struct exec_info *execi, off_t off, 11 vir_bytes seg_addr, size_t seg_bytes); 12 13 /* Array of loaders for different object formats */ 14 static struct exec_loaders { 15 libexec_exec_loadfunc_t load_object; 16 } const exec_loaders[] = { 17 { libexec_load_elf }, 18 { NULL } 19 }; 20 21 int srv_execve(int proc_e, char *exec, size_t exec_len, char **argv, 22 char **envp) 23 { 24 size_t frame_size = 0; /* Size of the new initial stack. */ 25 int argc = 0; /* Argument count. */ 26 int envc = 0; /* Environment count */ 27 char overflow = 0; /* No overflow yet. */ 28 char *frame; 29 struct ps_strings *psp; 30 int vsp = 0; /* (virtual) Stack pointer in new address space. */ 31 32 char *progname; 33 int r; 34 35 minix_stack_params(argv[0], argv, envp, &frame_size, &overflow, 36 &argc, &envc); 37 38 /* The party is off if there is an overflow. */ 39 if (overflow) { 40 errno = E2BIG; 41 return -1; 42 } 43 44 /* Allocate space for the stack frame. */ 45 if ((frame = (char *) sbrk(frame_size)) == (char *) -1) { 46 errno = E2BIG; 47 return -1; 48 } 49 50 minix_stack_fill(argv[0], argc, argv, envc, envp, frame_size, frame, 51 &vsp, &psp); 52 53 (progname=strrchr(argv[0], '/')) ? progname++ : (progname=argv[0]); 54 55 r = do_exec(proc_e, exec, exec_len, progname, frame, frame_size, 56 vsp + ((char *)psp - frame)); 57 58 /* Failure, return the memory used for the frame and exit. */ 59 (void) sbrk(-frame_size); 60 61 return r; 62 } 63 64 65 static int do_exec(int proc_e, char *exec, size_t exec_len, char *progname, 66 char *frame, int frame_len, vir_bytes ps_str) 67 { 68 int r; 69 vir_bytes vsp; 70 struct exec_info execi; 71 int i; 72 73 memset(&execi, 0, sizeof(execi)); 74 75 execi.stack_high = minix_get_user_sp(); 76 execi.stack_size = DEFAULT_STACK_LIMIT; 77 execi.proc_e = proc_e; 78 execi.hdr = exec; 79 execi.filesize = execi.hdr_len = exec_len; 80 strncpy(execi.progname, progname, PROC_NAME_LEN-1); 81 execi.progname[PROC_NAME_LEN-1] = '\0'; 82 execi.frame_len = frame_len; 83 84 /* callback functions and data */ 85 execi.copymem = read_seg; 86 execi.clearproc = libexec_clearproc_vm_procctl; 87 execi.clearmem = libexec_clear_sys_memset; 88 execi.allocmem_prealloc_cleared = libexec_alloc_mmap_prealloc_cleared; 89 execi.allocmem_prealloc_junk = libexec_alloc_mmap_prealloc_junk; 90 execi.allocmem_ondemand = libexec_alloc_mmap_ondemand; 91 92 for(i = 0; exec_loaders[i].load_object != NULL; i++) { 93 r = (*exec_loaders[i].load_object)(&execi); 94 /* Loaded successfully, so no need to try other loaders */ 95 if (r == OK) break; 96 } 97 98 /* No exec loader could load the object */ 99 if (r != OK) { 100 printf("RS: do_exec: loading error %d\n", r); 101 return r; 102 } 103 104 /* Inform PM */ 105 if((r = libexec_pm_newexec(execi.proc_e, &execi)) != OK) 106 return r; 107 108 /* Patch up stack and copy it from RS to new core image. */ 109 vsp = execi.stack_high - frame_len; 110 r = sys_datacopy(SELF, (vir_bytes) frame, 111 proc_e, (vir_bytes) vsp, (phys_bytes)frame_len); 112 if (r != OK) { 113 printf("do_exec: copying out new stack failed: %d\n", r); 114 exec_restart(proc_e, r, execi.pc, ps_str); 115 return r; 116 } 117 118 return exec_restart(proc_e, OK, execi.pc, ps_str); 119 } 120 121 /*===========================================================================* 122 * exec_restart * 123 *===========================================================================*/ 124 static int exec_restart(int proc_e, int result, vir_bytes pc, vir_bytes ps_str) 125 { 126 int r; 127 message m; 128 129 memset(&m, 0, sizeof(m)); 130 m.m_type = PM_EXEC_RESTART; 131 m.m_rs_pm_exec_restart.endpt = proc_e; 132 m.m_rs_pm_exec_restart.result = result; 133 m.m_rs_pm_exec_restart.pc = pc; 134 m.m_rs_pm_exec_restart.ps_str = ps_str; 135 136 r = ipc_sendrec(PM_PROC_NR, &m); 137 if (r != OK) 138 return r; 139 140 return m.m_type; 141 } 142 143 /*===========================================================================* 144 * read_seg * 145 *===========================================================================*/ 146 static int read_seg( 147 struct exec_info *execi, /* various data needed for exec */ 148 off_t off, /* offset in file */ 149 vir_bytes seg_addr, /* address to load segment */ 150 size_t seg_bytes /* how much is to be transferred? */ 151 ) 152 { 153 /* 154 * The byte count on read is usually smaller than the segment count, because 155 * a segment is padded out to a click multiple, and the data segment is only 156 * partially initialized. 157 */ 158 159 int r; 160 161 if (off+seg_bytes > execi->hdr_len) return ENOEXEC; 162 if((r= sys_datacopy(SELF, ((vir_bytes)execi->hdr)+off, 163 execi->proc_e, seg_addr, seg_bytes)) != OK) { 164 printf("RS: exec read_seg: copy 0x%x bytes into %i at 0x%08lx failed: %i\n", 165 (int) seg_bytes, execi->proc_e, seg_addr, r); 166 } 167 return r; 168 } 169