769af57274
. new mode for sys_memset: include process so memset can be done in physical or virtual address space. . add a mode to mmap() that lets a process allocate uninitialized memory. . this allows an exec()er (RS, VFS, etc.) to request uninitialized memory from VM and selectively clear the ranges that don't come from a file, leaving no uninitialized memory left for the process to see. . use callbacks for clearing the process, clearing memory in the process, and copying into the process; so that the libexec code can be used from rs, vfs, and in the future, kernel (to load vm) and vm (to load boot-time processes)
93 lines
2.4 KiB
C
93 lines
2.4 KiB
C
#define _SYSTEM 1
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#include <minix/type.h>
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#include <minix/const.h>
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#include <sys/param.h>
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#include <assert.h>
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#include <unistd.h>
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#include <errno.h>
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#include <libexec.h>
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#include <string.h>
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#include <assert.h>
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#include <minix/ipc.h>
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#include <minix/com.h>
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#include <minix/callnr.h>
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#include <minix/vm.h>
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#include <minix/syslib.h>
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#include <sys/mman.h>
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#include <machine/elf.h>
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int libexec_alloc_mmap_prealloc(struct exec_info *execi, off_t vaddr, size_t len)
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{
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if(minix_mmap_for(execi->proc_e, (void *) vaddr, len,
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PROT_READ|PROT_WRITE|PROT_EXEC,
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MAP_ANON|MAP_PREALLOC|MAP_UNINITIALIZED|MAP_FIXED, -1, 0) == MAP_FAILED) {
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return ENOMEM;
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}
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return OK;
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}
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int libexec_alloc_mmap_ondemand(struct exec_info *execi, off_t vaddr, size_t len)
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{
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if(minix_mmap_for(execi->proc_e, (void *) vaddr, len,
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PROT_READ|PROT_WRITE|PROT_EXEC,
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MAP_ANON|MAP_FIXED, -1, 0) == MAP_FAILED) {
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return ENOMEM;
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}
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return OK;
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}
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int libexec_clearproc_vm_procctl(struct exec_info *execi)
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{
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return vm_procctl(execi->proc_e, VMPPARAM_CLEAR);
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}
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int libexec_clear_sys_memset(struct exec_info *execi, off_t vaddr, size_t len)
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{
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return sys_memset(execi->proc_e, 0, vaddr, len);
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}
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void libexec_patch_ptr(char stack[ARG_MAX], vir_bytes base)
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{
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/* When doing an exec(name, argv, envp) call, the user builds up a stack
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* image with arg and env pointers relative to the start of the stack. Now
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* these pointers must be relocated, since the stack is not positioned at
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* address 0 in the user's address space.
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*/
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char **ap, flag;
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vir_bytes v;
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flag = 0; /* counts number of 0-pointers seen */
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ap = (char **) stack; /* points initially to 'nargs' */
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ap++; /* now points to argv[0] */
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while (flag < 2) {
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if (ap >= (char **) &stack[ARG_MAX]) return; /* too bad */
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if (*ap != NULL) {
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v = (vir_bytes) *ap; /* v is relative pointer */
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v += base; /* relocate it */
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*ap = (char *) v; /* put it back */
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} else {
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flag++;
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}
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ap++;
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}
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}
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int libexec_pm_newexec(endpoint_t proc_e, struct exec_info *e)
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{
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int r;
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message m;
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m.m_type = PM_NEWEXEC;
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m.EXC_NM_PROC = proc_e;
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m.EXC_NM_PTR = (char *)e;
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if ((r = sendrec(PM_PROC_NR, &m)) != OK) return(r);
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e->allow_setuid = !!(m.m1_i2 & EXC_NM_RF_ALLOW_SETUID);
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return(m.m_type);
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}
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