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VFS/RS support for ELF

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This commit is contained in:
Arun Thomas
2010-12-10 09:27:56 +00:00
parent 9639af49d2
commit 372b873413
22 changed files with 2412 additions and 386 deletions
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servers/rs/Makefile
+2 -2
View File
@@ -4,8 +4,8 @@
PROG= rs
SRCS= exec.c main.c request.c manager.c table.c utility.c memory.c error.c
DPADD+= ${LIBSYS}
LDADD+= -lsys
DPADD+= ${LIBSYS} ${LIBEXEC}
LDADD+= -lsys -lexec
MAN=
servers/rs/exec.c
+191 -165
View File
@@ -1,26 +1,35 @@
#include "inc.h"
#include <a.out.h>
#include <assert.h>
#include <libexec.h>
#include "exec.h"
#define BLOCK_SIZE 1024
static int do_exec(int proc_e, char *exec, size_t exec_len, char *progname,
char *frame, int frame_len);
FORWARD _PROTOTYPE( int read_header, (char *exec, size_t exec_len, int *sep_id,
vir_bytes *text_bytes, vir_bytes *data_bytes,
vir_bytes *bss_bytes, phys_bytes *tot_bytes, vir_bytes *pc,
int *hdrlenp) );
FORWARD _PROTOTYPE( int exec_newmem, (int proc_e, vir_bytes text_bytes,
vir_bytes data_bytes, vir_bytes bss_bytes, vir_bytes tot_bytes,
vir_bytes frame_len, int sep_id,
static int exec_newmem(int proc_e, vir_bytes text_addr,
vir_bytes text_bytes, vir_bytes data_addr,
vir_bytes data_bytes, vir_bytes tot_bytes,
vir_bytes frame_len, int sep_id, int is_elf,
dev_t st_dev, ino_t st_ino, time_t st_ctime, char *progname,
int new_uid, int new_gid,
vir_bytes *stack_topp, int *load_textp, int *allow_setuidp) );
FORWARD _PROTOTYPE( int exec_restart, (int proc_e, int result,
vir_bytes pc) );
FORWARD _PROTOTYPE( void patch_ptr, (char stack[ARG_MAX],
vir_bytes base) );
FORWARD _PROTOTYPE( int read_seg, (char *exec, size_t exec_len, off_t off,
int proc_e, int seg, phys_bytes seg_bytes) );
int new_uid, int new_gid, vir_bytes *stack_topp,
int *load_textp, int *allow_setuidp);
static void patch_ptr(char stack[ARG_MAX], vir_bytes base);
static int exec_restart(int proc_e, int result, vir_bytes pc);
static int read_seg(struct exec_info *execi, off_t off,
int proc_e, int seg, vir_bytes seg_addr, phys_bytes seg_bytes);
static int load_aout(struct exec_info *execi);
static int load_elf(struct exec_info *execi);
/* Array of loaders for different object formats */
struct exec_loaders {
int (*load_object)(struct exec_info *);
} static const exec_loaders[] = {
{ load_aout },
{ load_elf },
{ NULL }
};
int srv_execve(int proc_e, char *exec, size_t exec_len, char **argv,
char **Xenvp)
@@ -112,107 +121,201 @@ int srv_execve(int proc_e, char *exec, size_t exec_len, char **argv,
return r;
}
static int do_exec(int proc_e, char *exec, size_t exec_len, char *progname,
char *frame, int frame_len)
{
int r;
int hdrlen, sep_id, load_text, allow_setuid;
int need_restart, error;
vir_bytes stack_top, vsp;
vir_bytes text_bytes, data_bytes, bss_bytes, pc;
phys_bytes tot_bytes;
off_t off;
uid_t new_uid;
gid_t new_gid;
vir_bytes vsp;
struct exec_info execi;
int i;
need_restart= 0;
error= 0;
execi.proc_e = proc_e;
execi.image = exec;
execi.image_len = exec_len;
strncpy(execi.progname, progname, PROC_NAME_LEN-1);
execi.progname[PROC_NAME_LEN-1] = '\0';
execi.frame_len = frame_len;
/* Read the file header and extract the segment sizes. */
r = read_header(exec, exec_len, &sep_id,
&text_bytes, &data_bytes, &bss_bytes,
&tot_bytes, &pc, &hdrlen);
if (r != OK)
{
printf("do_exec: read_header failed\n");
error= r;
goto fail;
for(i = 0; exec_loaders[i].load_object != NULL; i++) {
r = (*exec_loaders[i].load_object)(&execi);
/* Loaded successfully, so no need to try other loaders */
if (r == OK) break;
}
need_restart= 1;
new_uid= getuid();
new_gid= getgid();
/* XXX what should we use to identify the executable? */
r= exec_newmem(proc_e, text_bytes, data_bytes, bss_bytes, tot_bytes,
frame_len, sep_id, 0 /*dev*/, proc_e /*inum*/, 0 /*ctime*/,
progname, new_uid, new_gid, &stack_top, &load_text,
&allow_setuid);
if (r != OK)
{
printf("do_exec: exec_newmap failed: %d\n", r);
error= r;
goto fail;
/* No exec loader could load the object */
if (r != OK) {
printf("RS: do_exec: loading error %d\n", r);
return r;
}
/* Patch up stack and copy it from RS to new core image. */
vsp = stack_top;
vsp = execi.stack_top;
vsp -= frame_len;
patch_ptr(frame, vsp);
r = sys_datacopy(SELF, (vir_bytes) frame,
proc_e, (vir_bytes) vsp, (phys_bytes)frame_len);
if (r != OK) {
printf("RS: stack_top is 0x%lx; tried to copy to 0x%lx in %d\n",
stack_top, vsp, proc_e);
execi.stack_top, vsp, proc_e);
printf("do_exec: copying out new stack failed: %d\n", r);
error= r;
goto fail;
exec_restart(proc_e, r, execi.pc);
return r;
}
return exec_restart(proc_e, OK, execi.pc);
}
static int load_aout(struct exec_info *execi)
{
int r;
int hdrlen, sep_id, load_text, allow_setuid;
vir_bytes text_bytes, data_bytes, bss_bytes;
phys_bytes tot_bytes;
off_t off;
uid_t new_uid;
gid_t new_gid;
int proc_e;
assert(execi != NULL);
assert(execi->image != NULL);
proc_e = execi->proc_e;
/* Read the file header and extract the segment sizes. */
r = read_header_aout(execi->image, execi->image_len, &sep_id,
&text_bytes, &data_bytes, &bss_bytes,
&tot_bytes, &execi->pc, &hdrlen);
if (r != OK)
{
return r;
}
new_uid= getuid();
new_gid= getgid();
/* XXX what should we use to identify the executable? */
r= exec_newmem(proc_e, 0 /*text_addr*/, text_bytes,
0 /*data_addr*/, data_bytes + bss_bytes, tot_bytes,
execi->frame_len, sep_id, 0 /*is_elf*/, 0 /*dev*/, proc_e /*inum*/, 0 /*ctime*/,
execi->progname, new_uid, new_gid, &execi->stack_top, &load_text,
&allow_setuid);
if (r != OK)
{
printf("RS: load_aout: exec_newmem failed: %d\n", r);
exec_restart(proc_e, r, execi->pc);
return r;
}
off = hdrlen;
/* Read in text and data segments. */
if (load_text) {
r= read_seg(exec, exec_len, off, proc_e, T, text_bytes);
r= read_seg(execi, off, proc_e, T, 0, text_bytes);
if (r != OK)
{
printf("do_exec: read_seg failed: %d\n", r);
error= r;
goto fail;
printf("RS: load_aout: read_seg failed: %d\n", r);
exec_restart(proc_e, r, execi->pc);
return r;
}
}
else
printf("do_exec: not loading text segment\n");
printf("RS: load_aout: not loading text segment\n");
off += text_bytes;
r= read_seg(exec, exec_len, off, proc_e, D, data_bytes);
r= read_seg(execi, off, proc_e, D, 0, data_bytes);
if (r != OK)
{
printf("do_exec: read_seg failed: %d\n", r);
error= r;
goto fail;
printf("RS: load_aout: read_seg failed: %d\n", r);
exec_restart(proc_e, r, execi->pc);
return r;
}
return exec_restart(proc_e, OK, pc);
return OK;
}
fail:
printf("do_exec(fail): error = %d\n", error);
if (need_restart)
exec_restart(proc_e, error, pc);
static int load_elf(struct exec_info *execi)
{
int r;
int proc_e;
phys_bytes tot_bytes; /* total space for program, including gap */
vir_bytes text_addr, text_filebytes, text_membytes;
vir_bytes data_addr, data_filebytes, data_membytes;
off_t text_offset, data_offset;
int sep_id, is_elf, load_text, allow_setuid;
uid_t new_uid;
gid_t new_gid;
return error;
assert(execi != NULL);
assert(execi->image != NULL);
proc_e = execi->proc_e;
/* Read the file header and extract the segment sizes. */
r = read_header_elf(execi->image, &text_addr, &text_filebytes, &text_membytes,
&data_addr, &data_filebytes, &data_membytes,
&tot_bytes, &execi->pc, &text_offset, &data_offset);
if (r != OK) {
return(r);
}
new_uid= getuid();
new_gid= getgid();
sep_id = 1;
is_elf = 1;
r = exec_newmem(proc_e,
trunc_page(text_addr), text_membytes,
trunc_page(data_addr), data_membytes,
tot_bytes, execi->frame_len, sep_id, is_elf,
0 /*dev*/, proc_e /*inum*/, 0 /*ctime*/,
execi->progname, new_uid, new_gid,
&execi->stack_top, &load_text, &allow_setuid);
if (r != OK)
{
printf("RS: load_elf: exec_newmem failed: %d\n", r);
exec_restart(proc_e, r, execi->pc);
return r;
}
/* Read in text and data segments. */
if (load_text) {
r = read_seg(execi, text_offset, proc_e, T, text_addr, text_filebytes);
if (r != OK)
{
printf("RS: load_elf: read_seg failed: %d\n", r);
exec_restart(proc_e, r, execi->pc);
return r;
}
}
else
printf("RS: load_elf: not loading text segment\n");
r = read_seg(execi, data_offset, proc_e, D, data_addr, data_filebytes);
if (r != OK)
{
printf("RS: load_elf: read_seg failed: %d\n", r);
exec_restart(proc_e, r, execi->pc);
return r;
}
return(OK);
}
/*===========================================================================*
* exec_newmem *
*===========================================================================*/
PRIVATE int exec_newmem(
static int exec_newmem(
int proc_e,
vir_bytes text_addr,
vir_bytes text_bytes,
vir_bytes data_addr,
vir_bytes data_bytes,
vir_bytes bss_bytes,
vir_bytes tot_bytes,
vir_bytes frame_len,
int sep_id,
int is_elf,
dev_t st_dev,
ino_t st_ino,
time_t st_ctime,
@@ -228,12 +331,14 @@ PRIVATE int exec_newmem(
struct exec_newmem e;
message m;
e.text_addr = text_addr;
e.text_bytes= text_bytes;
e.data_addr = data_addr;
e.data_bytes= data_bytes;
e.bss_bytes= bss_bytes;
e.tot_bytes= tot_bytes;
e.args_bytes= frame_len;
e.sep_id= sep_id;
e.is_elf= is_elf;
e.st_dev= st_dev;
e.st_ino= st_ino;
e.st_ctime= st_ctime;
@@ -265,10 +370,7 @@ PRIVATE int exec_newmem(
/*===========================================================================*
* exec_restart *
*===========================================================================*/
PRIVATE int exec_restart(proc_e, result, pc)
int proc_e;
int result;
vir_bytes pc;
static int exec_restart(int proc_e, int result, vir_bytes pc)
{
int r;
message m;
@@ -283,91 +385,13 @@ vir_bytes pc;
return m.m_type;
}
/*===========================================================================*
* read_header *
*===========================================================================*/
PRIVATE int read_header(exec, exec_len, sep_id, text_bytes, data_bytes,
bss_bytes, tot_bytes, pc, hdrlenp)
char *exec; /* executable image */
size_t exec_len; /* size of the image */
int *sep_id; /* true iff sep I&D */
vir_bytes *text_bytes; /* place to return text size */
vir_bytes *data_bytes; /* place to return initialized data size */
vir_bytes *bss_bytes; /* place to return bss size */
phys_bytes *tot_bytes; /* place to return total size */
vir_bytes *pc; /* program entry point (initial PC) */
int *hdrlenp;
{
/* Read the header and extract the text, data, bss and total sizes from it. */
struct exec hdr; /* a.out header is read in here */
/* Read the header and check the magic number. The standard MINIX header
* is defined in <a.out.h>. It consists of 8 chars followed by 6 longs.
* Then come 4 more longs that are not used here.
* Byte 0: magic number 0x01
* Byte 1: magic number 0x03
* Byte 2: normal = 0x10 (not checked, 0 is OK), separate I/D = 0x20
* Byte 3: CPU type, Intel 16 bit = 0x04, Intel 32 bit = 0x10,
* Motorola = 0x0B, Sun SPARC = 0x17
* Byte 4: Header length = 0x20
* Bytes 5-7 are not used.
*
* Now come the 6 longs
* Bytes 8-11: size of text segments in bytes
* Bytes 12-15: size of initialized data segment in bytes
* Bytes 16-19: size of bss in bytes
* Bytes 20-23: program entry point
* Bytes 24-27: total memory allocated to program (text, data + stack)
* Bytes 28-31: size of symbol table in bytes
* The longs are represented in a machine dependent order,
* little-endian on the 8088, big-endian on the 68000.
* The header is followed directly by the text and data segments, and the
* symbol table (if any). The sizes are given in the header. Only the
* text and data segments are copied into memory by exec. The header is
* used here only. The symbol table is for the benefit of a debugger and
* is ignored here.
*/
if (exec_len < sizeof(hdr)) return(ENOEXEC);
memcpy(&hdr, exec, sizeof(hdr));
/* Check magic number, cpu type, and flags. */
if (BADMAG(hdr)) return(ENOEXEC);
#if (CHIP == INTEL && _WORD_SIZE == 2)
if (hdr.a_cpu != A_I8086) return(ENOEXEC);
#endif
#if (CHIP == INTEL && _WORD_SIZE == 4)
if (hdr.a_cpu != A_I80386) return(ENOEXEC);
#endif
if ((hdr.a_flags & ~(A_NSYM | A_EXEC | A_SEP)) != 0) return(ENOEXEC);
*sep_id = !!(hdr.a_flags & A_SEP); /* separate I & D or not */
/* Get text and data sizes. */
*text_bytes = (vir_bytes) hdr.a_text; /* text size in bytes */
*data_bytes = (vir_bytes) hdr.a_data; /* data size in bytes */
*bss_bytes = (vir_bytes) hdr.a_bss; /* bss size in bytes */
*tot_bytes = hdr.a_total; /* total bytes to allocate for prog */
if (*tot_bytes == 0) return(ENOEXEC);
if (!*sep_id) {
/* If I & D space is not separated, it is all considered data. Text=0*/
*data_bytes += *text_bytes;
*text_bytes = 0;
}
*pc = hdr.a_entry; /* initial address to start execution */
*hdrlenp = hdr.a_hdrlen & BYTE; /* header length */
return(OK);
}
/*===========================================================================*
* patch_ptr *
*===========================================================================*/
PRIVATE void patch_ptr(stack, base)
char stack[ARG_MAX]; /* pointer to stack image within PM */
vir_bytes base; /* virtual address of stack base inside user */
static void patch_ptr(
char stack[ARG_MAX], /* pointer to stack image within PM */
vir_bytes base /* virtual address of stack base inside user */
)
{
/* 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
@@ -397,13 +421,14 @@ vir_bytes base; /* virtual address of stack base inside user */
/*===========================================================================*
* read_seg *
*===========================================================================*/
PRIVATE int read_seg(exec, exec_len, off, proc_e, seg, seg_bytes)
char *exec; /* executable image */
size_t exec_len; /* size of the image */
off_t off; /* offset in file */
int proc_e; /* process number (endpoint) */
int seg; /* T, D, or S */
phys_bytes seg_bytes; /* how much is to be transferred? */
static int read_seg(
struct exec_info *execi, /* various data needed for exec */
off_t off, /* offset in file */
int proc_e, /* process number (endpoint) */
int seg, /* T, D, or S */
vir_bytes seg_addr, /* address to load segment */
phys_bytes seg_bytes /* how much is to be transferred? */
)
{
/*
* The byte count on read is usually smaller than the segment count, because
@@ -413,8 +438,9 @@ phys_bytes seg_bytes; /* how much is to be transferred? */
int r;
if (off+seg_bytes > exec_len) return ENOEXEC;
r= sys_vircopy(SELF, D, (vir_bytes)exec+off, proc_e, seg, 0, seg_bytes);
assert((seg == T)||(seg == D));
if (off+seg_bytes > execi->image_len) return ENOEXEC;
r= sys_vircopy(SELF, D, ((vir_bytes)execi->image)+off, proc_e, seg, seg_addr, seg_bytes);
return r;
}
servers/rs/exec.h
+14
View File
@@ -0,0 +1,14 @@
#ifndef _RS_EXEC_H_
#define _RS_EXEC_H_ 1
struct exec_info {
int proc_e; /* Process endpoint */
char *image; /* Executable image */
size_t image_len; /* Size of executable image */
vir_bytes pc; /* Entry point of exec file */
vir_bytes stack_top; /* Top of the stack */
vir_bytes frame_len; /* Stack size */
char progname[PROC_NAME_LEN]; /* Program name */
};
#endif /* !_RS_EXEC_H_ */