first self virtualizable version
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@89 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/Makefile b/Makefile
index 96810ca..f6d1e27 100644
--- a/Makefile
+++ b/Makefile
@@ -105,7 +105,7 @@
FILES= \
README README.distrib COPYING COPYING.LIB TODO Changelog VERSION \
dyngen.c ioctls.h ops_template.h op_string.h syscall_types.h\
-Makefile elf.h linux_bin.h segment.h thunk.c\
+Makefile elf.h thunk.c\
elfload.c main.c signal.c thunk.h\
cpu-i386.h qemu.h op-i386.c opc-i386.h syscall-i386.h translate-i386.c\
dis-asm.h gen-i386.h syscall.c\
diff --git a/TODO b/TODO
index eb79f2b..66ecfea 100644
--- a/TODO
+++ b/TODO
@@ -7,5 +7,6 @@
issues, fix 16 bit uid issues)
- finish signal handing (fp87 state, more siginfo conversions)
- verify thread support (clone() and various locks)
-- make it self runnable (use same trick as ld.so : include its own relocator and libc)
+- make it self runnable (handle self modifying code, relocate stack
+ and dyn loader)
- fix FPU exceptions (in particular: gen_op_fpush not before mem load)
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 78d477c..c692ea3 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -49,9 +49,78 @@
#endif
-#include "linux_bin.h"
#include "elf.h"
-#include "segment.h"
+
+/*
+ * MAX_ARG_PAGES defines the number of pages allocated for arguments
+ * and envelope for the new program. 32 should suffice, this gives
+ * a maximum env+arg of 128kB w/4KB pages!
+ */
+#define MAX_ARG_PAGES 32
+
+/*
+ * This structure is used to hold the arguments that are
+ * used when loading binaries.
+ */
+struct linux_binprm {
+ char buf[128];
+ unsigned long page[MAX_ARG_PAGES];
+ unsigned long p;
+ int sh_bang;
+ int fd;
+ int e_uid, e_gid;
+ int argc, envc;
+ char * interp_prefix; /* prefix for interpreter */
+ char * filename; /* Name of binary */
+ unsigned long loader, exec;
+ int dont_iput; /* binfmt handler has put inode */
+};
+
+struct exec
+{
+ unsigned int a_info; /* Use macros N_MAGIC, etc for access */
+ unsigned int a_text; /* length of text, in bytes */
+ unsigned int a_data; /* length of data, in bytes */
+ unsigned int a_bss; /* length of uninitialized data area, in bytes */
+ unsigned int a_syms; /* length of symbol table data in file, in bytes */
+ unsigned int a_entry; /* start address */
+ unsigned int a_trsize; /* length of relocation info for text, in bytes */
+ unsigned int a_drsize; /* length of relocation info for data, in bytes */
+};
+
+
+#define N_MAGIC(exec) ((exec).a_info & 0xffff)
+#define OMAGIC 0407
+#define NMAGIC 0410
+#define ZMAGIC 0413
+#define QMAGIC 0314
+
+#define X86_STACK_TOP 0x7d000000
+
+/* max code+data+bss space allocated to elf interpreter */
+#define INTERP_MAP_SIZE (32 * 1024 * 1024)
+
+/* max code+data+bss+brk space allocated to ET_DYN executables */
+#define ET_DYN_MAP_SIZE (128 * 1024 * 1024)
+
+/* from personality.h */
+
+/* Flags for bug emulation. These occupy the top three bytes. */
+#define STICKY_TIMEOUTS 0x4000000
+#define WHOLE_SECONDS 0x2000000
+
+/* Personality types. These go in the low byte. Avoid using the top bit,
+ * it will conflict with error returns.
+ */
+#define PER_MASK (0x00ff)
+#define PER_LINUX (0x0000)
+#define PER_SVR4 (0x0001 | STICKY_TIMEOUTS)
+#define PER_SVR3 (0x0002 | STICKY_TIMEOUTS)
+#define PER_SCOSVR3 (0x0003 | STICKY_TIMEOUTS | WHOLE_SECONDS)
+#define PER_WYSEV386 (0x0004 | STICKY_TIMEOUTS)
+#define PER_ISCR4 (0x0005 | STICKY_TIMEOUTS)
+#define PER_BSD (0x0006)
+#define PER_XENIX (0x0007 | STICKY_TIMEOUTS)
/* Necessary parameters */
#define ALPHA_PAGE_SIZE 4096
@@ -78,8 +147,18 @@
#define DLINFO_ITEMS 12
-/* Where we find X86 libraries... */
+#define put_user(x,ptr) (void)(*(ptr) = (typeof(*ptr))(x))
+#define get_user(ptr) (typeof(*ptr))(*(ptr))
+static inline void memcpy_fromfs(void * to, const void * from, unsigned long n)
+{
+ memcpy(to, from, n);
+}
+
+static inline void memcpy_tofs(void * to, const void * from, unsigned long n)
+{
+ memcpy(to, from, n);
+}
//extern void * mmap4k();
#define mmap4k(a, b, c, d, e, f) mmap((void *)(a), b, c, d, e, f)
@@ -282,42 +361,34 @@
unsigned long setup_arg_pages(unsigned long p, struct linux_binprm * bprm,
struct image_info * info)
{
- unsigned long stack_base;
+ unsigned long stack_base, size, error;
int i;
- extern unsigned long stktop;
-
- stack_base = X86_STACK_TOP - MAX_ARG_PAGES*X86_PAGE_SIZE;
-
- p += stack_base;
- if (bprm->loader) {
- bprm->loader += stack_base;
- }
- bprm->exec += stack_base;
/* Create enough stack to hold everything. If we don't use
* it for args, we'll use it for something else...
*/
- /* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
- we allocate a bigger stack. Need a better solution, for example
- by remapping the process stack directly at the right place */
- if(x86_stack_size > MAX_ARG_PAGES*X86_PAGE_SIZE) {
- if((long)mmap4k((void *)(X86_STACK_TOP-x86_stack_size), x86_stack_size + X86_PAGE_SIZE,
- PROT_READ | PROT_WRITE,
- MAP_GROWSDOWN | MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) == -1) {
- perror("stk mmap");
- exit(-1);
- }
+ size = x86_stack_size;
+ if (size < MAX_ARG_PAGES*X86_PAGE_SIZE)
+ size = MAX_ARG_PAGES*X86_PAGE_SIZE;
+ error = (unsigned long)mmap4k(NULL,
+ size + X86_PAGE_SIZE,
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS,
+ -1, 0);
+ if (error == -1) {
+ perror("stk mmap");
+ exit(-1);
}
- else {
- if((long)mmap4k((void *)stack_base, (MAX_ARG_PAGES+1)*X86_PAGE_SIZE,
- PROT_READ | PROT_WRITE,
- MAP_GROWSDOWN | MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) == -1) {
- perror("stk mmap");
- exit(-1);
- }
+ /* we reserve one extra page at the top of the stack as guard */
+ mprotect((void *)(error + size), X86_PAGE_SIZE, PROT_NONE);
+
+ stack_base = error + size - MAX_ARG_PAGES*X86_PAGE_SIZE;
+ p += stack_base;
+
+ if (bprm->loader) {
+ bprm->loader += stack_base;
}
-
- stktop = stack_base;
+ bprm->exec += stack_base;
for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
if (bprm->page[i]) {
@@ -369,10 +440,11 @@
}
static unsigned int * create_elf_tables(char *p, int argc, int envc,
- struct elfhdr * exec,
- unsigned long load_addr,
- unsigned long interp_load_addr, int ibcs,
- struct image_info *info)
+ struct elfhdr * exec,
+ unsigned long load_addr,
+ unsigned long load_bias,
+ unsigned long interp_load_addr, int ibcs,
+ struct image_info *info)
{
target_ulong *argv, *envp, *dlinfo;
target_ulong *sp;
@@ -397,17 +469,17 @@
put_user (tswapl(val), dlinfo++)
if (exec) { /* Put this here for an ELF program interpreter */
- NEW_AUX_ENT (AT_PHDR, (unsigned int)(load_addr + exec->e_phoff));
- NEW_AUX_ENT (AT_PHENT, (unsigned int)(sizeof (struct elf_phdr)));
- NEW_AUX_ENT (AT_PHNUM, (unsigned int)(exec->e_phnum));
- NEW_AUX_ENT (AT_PAGESZ, (unsigned int)(ALPHA_PAGE_SIZE));
- NEW_AUX_ENT (AT_BASE, (unsigned int)(interp_load_addr));
- NEW_AUX_ENT (AT_FLAGS, (unsigned int)0);
- NEW_AUX_ENT (AT_ENTRY, (unsigned int) exec->e_entry);
- NEW_AUX_ENT (AT_UID, (unsigned int) getuid());
- NEW_AUX_ENT (AT_EUID, (unsigned int) geteuid());
- NEW_AUX_ENT (AT_GID, (unsigned int) getgid());
- NEW_AUX_ENT (AT_EGID, (unsigned int) getegid());
+ NEW_AUX_ENT (AT_PHDR, (target_ulong)(load_addr + exec->e_phoff));
+ NEW_AUX_ENT (AT_PHENT, (target_ulong)(sizeof (struct elf_phdr)));
+ NEW_AUX_ENT (AT_PHNUM, (target_ulong)(exec->e_phnum));
+ NEW_AUX_ENT (AT_PAGESZ, (target_ulong)(ALPHA_PAGE_SIZE));
+ NEW_AUX_ENT (AT_BASE, (target_ulong)(interp_load_addr));
+ NEW_AUX_ENT (AT_FLAGS, (target_ulong)0);
+ NEW_AUX_ENT (AT_ENTRY, load_bias + exec->e_entry);
+ NEW_AUX_ENT (AT_UID, (target_ulong) getuid());
+ NEW_AUX_ENT (AT_EUID, (target_ulong) geteuid());
+ NEW_AUX_ENT (AT_GID, (target_ulong) getgid());
+ NEW_AUX_ENT (AT_EGID, (target_ulong) getegid());
}
NEW_AUX_ENT (AT_NULL, 0);
#undef NEW_AUX_ENT
@@ -436,7 +508,7 @@
{
struct elf_phdr *elf_phdata = NULL;
struct elf_phdr *eppnt;
- unsigned long load_addr;
+ unsigned long load_addr = 0;
int load_addr_set = 0;
int retval;
unsigned long last_bss, elf_bss;
@@ -447,17 +519,12 @@
last_bss = 0;
error = 0;
- /* We put this here so that mmap will search for the *first*
- * available memory...
- */
- load_addr = INTERP_LOADADDR;
-
#ifdef BSWAP_NEEDED
bswap_ehdr(interp_elf_ex);
#endif
/* First of all, some simple consistency checks */
if ((interp_elf_ex->e_type != ET_EXEC &&
- interp_elf_ex->e_type != ET_DYN) ||
+ interp_elf_ex->e_type != ET_DYN) ||
!elf_check_arch(interp_elf_ex->e_machine)) {
return ~0UL;
}
@@ -478,11 +545,10 @@
* If the size of this structure has changed, then punt, since
* we will be doing the wrong thing.
*/
- if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
- {
+ if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr)) {
free(elf_phdata);
return ~0UL;
- }
+ }
retval = lseek(interpreter_fd, interp_elf_ex->e_phoff, SEEK_SET);
if(retval >= 0) {
@@ -502,6 +568,21 @@
bswap_phdr(eppnt);
}
#endif
+
+ if (interp_elf_ex->e_type == ET_DYN) {
+ /* in order to avoid harcoding the interpreter load
+ address in qemu, we allocate a big enough memory zone */
+ error = (unsigned long)mmap4k(NULL, INTERP_MAP_SIZE,
+ PROT_NONE, MAP_PRIVATE | MAP_ANON,
+ -1, 0);
+ if (error == -1) {
+ perror("mmap");
+ exit(-1);
+ }
+ load_addr = error;
+ load_addr_set = 1;
+ }
+
eppnt = elf_phdata;
for(i=0; i<interp_elf_ex->e_phnum; i++, eppnt++)
if (eppnt->p_type == PT_LOAD) {
@@ -585,7 +666,7 @@
struct elfhdr interp_elf_ex;
struct exec interp_ex;
int interpreter_fd = -1; /* avoid warning */
- unsigned long load_addr;
+ unsigned long load_addr, load_bias;
int load_addr_set = 0;
unsigned int interpreter_type = INTERPRETER_NONE;
unsigned char ibcs2_interpreter;
@@ -605,6 +686,7 @@
ibcs2_interpreter = 0;
status = 0;
load_addr = 0;
+ load_bias = 0;
elf_ex = *((struct elfhdr *) bprm->buf); /* exec-header */
#ifdef BSWAP_NEEDED
bswap_ehdr(&elf_ex);
@@ -810,56 +892,86 @@
* address.
*/
-
-
for(i = 0, elf_ppnt = elf_phdata; i < elf_ex.e_phnum; i++, elf_ppnt++) {
- if (elf_ppnt->p_type == PT_LOAD) {
- int elf_prot = 0;
- if (elf_ppnt->p_flags & PF_R) elf_prot |= PROT_READ;
- if (elf_ppnt->p_flags & PF_W) elf_prot |= PROT_WRITE;
- if (elf_ppnt->p_flags & PF_X) elf_prot |= PROT_EXEC;
-
- mapped_addr = mmap4k(X86_ELF_PAGESTART(elf_ppnt->p_vaddr),
- (elf_ppnt->p_filesz +
- X86_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)),
- elf_prot,
- (MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE),
- bprm->fd,
- (elf_ppnt->p_offset -
- X86_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)));
-
- if((unsigned long)mapped_addr == 0xffffffffffffffff) {
- perror("mmap");
- exit(-1);
- }
-
-
+ int elf_prot = 0;
+ int elf_flags = 0;
+ unsigned long error;
+
+ if (elf_ppnt->p_type != PT_LOAD)
+ continue;
+
+ if (elf_ppnt->p_flags & PF_R) elf_prot |= PROT_READ;
+ if (elf_ppnt->p_flags & PF_W) elf_prot |= PROT_WRITE;
+ if (elf_ppnt->p_flags & PF_X) elf_prot |= PROT_EXEC;
+ elf_flags = MAP_PRIVATE | MAP_DENYWRITE;
+ if (elf_ex.e_type == ET_EXEC || load_addr_set) {
+ elf_flags |= MAP_FIXED;
+ } else if (elf_ex.e_type == ET_DYN) {
+ /* Try and get dynamic programs out of the way of the default mmap
+ base, as well as whatever program they might try to exec. This
+ is because the brk will follow the loader, and is not movable. */
+ /* NOTE: for qemu, we do a big mmap to get enough space
+ without harcoding any address */
+ error = (unsigned long)mmap4k(NULL, ET_DYN_MAP_SIZE,
+ PROT_NONE, MAP_PRIVATE | MAP_ANON,
+ -1, 0);
+ if (error == -1) {
+ perror("mmap");
+ exit(-1);
+ }
+ load_bias = X86_ELF_PAGESTART(error - elf_ppnt->p_vaddr);
+ }
+
+ error = (unsigned long)mmap4k(
+ X86_ELF_PAGESTART(load_bias + elf_ppnt->p_vaddr),
+ (elf_ppnt->p_filesz +
+ X86_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)),
+ elf_prot,
+ (MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE),
+ bprm->fd,
+ (elf_ppnt->p_offset -
+ X86_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)));
+ if (error == -1) {
+ perror("mmap");
+ exit(-1);
+ }
#ifdef LOW_ELF_STACK
- if (X86_ELF_PAGESTART(elf_ppnt->p_vaddr) < elf_stack)
- elf_stack = X86_ELF_PAGESTART(elf_ppnt->p_vaddr);
+ if (X86_ELF_PAGESTART(elf_ppnt->p_vaddr) < elf_stack)
+ elf_stack = X86_ELF_PAGESTART(elf_ppnt->p_vaddr);
#endif
-
- if (!load_addr_set) {
- load_addr = elf_ppnt->p_vaddr - elf_ppnt->p_offset;
- load_addr_set = 1;
- }
- k = elf_ppnt->p_vaddr;
- if (k < start_code) start_code = k;
- k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
- if (k > elf_bss) elf_bss = k;
-#if 1
- if ((elf_ppnt->p_flags & PF_X) && end_code < k)
-#else
- if ( !(elf_ppnt->p_flags & PF_W) && end_code < k)
-#endif
- end_code = k;
- if (end_data < k) end_data = k;
- k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
- if (k > elf_brk) elf_brk = k;
- }
+
+ if (!load_addr_set) {
+ load_addr_set = 1;
+ load_addr = elf_ppnt->p_vaddr - elf_ppnt->p_offset;
+ if (elf_ex.e_type == ET_DYN) {
+ load_bias += error -
+ X86_ELF_PAGESTART(load_bias + elf_ppnt->p_vaddr);
+ load_addr += load_bias;
+ }
+ }
+ k = elf_ppnt->p_vaddr;
+ if (k < start_code)
+ start_code = k;
+ k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
+ if (k > elf_bss)
+ elf_bss = k;
+ if ((elf_ppnt->p_flags & PF_X) && end_code < k)
+ end_code = k;
+ if (end_data < k)
+ end_data = k;
+ k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
+ if (k > elf_brk) elf_brk = k;
}
+ elf_entry += load_bias;
+ elf_bss += load_bias;
+ elf_brk += load_bias;
+ start_code += load_bias;
+ end_code += load_bias;
+ // start_data += load_bias;
+ end_data += load_bias;
+
if (elf_interpreter) {
if (interpreter_type & 1) {
elf_entry = load_aout_interp(&interp_ex, interpreter_fd);
@@ -893,7 +1005,7 @@
bprm->argc,
bprm->envc,
(interpreter_type == INTERPRETER_ELF ? &elf_ex : NULL),
- load_addr,
+ load_addr, load_bias,
interp_load_addr,
(interpreter_type == INTERPRETER_AOUT ? 0 : 1),
info);
diff --git a/linux-user/main.c b/linux-user/main.c
index d7c68a9..0c8480d 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -47,7 +47,6 @@
we allocate a bigger stack. Need a better solution, for example
by remapping the process stack directly at the right place */
unsigned long x86_stack_size = 512 * 1024;
-unsigned long stktop;
void gemu_log(const char *fmt, ...)
{
