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authorRichard Henderson <rth@twiddle.net>2010-07-27 10:25:38 -0700
committerEdgar E. Iglesias <edgar.iglesias@gmail.com>2010-07-29 08:32:28 +0200
commitbf858897b76926b56e948dbe7a1a491b68dccda7 (patch)
tree12b001dfff752a32a16a891f1d7a89b240599926
parent8e62a71738bcbefdbb76435d94be5d455b9ee192 (diff)
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linux-user: Re-use load_elf_image for the main binary.
This requires moving the PT_INTERP extraction and GUEST_BASE handling into load_elf_image. Key this off a non-null pointer argument to receive the interpreter name. Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
-rw-r--r--linux-user/elfload.c380
1 files changed, 103 insertions, 277 deletions
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 0a3d084..a53285a 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -829,9 +829,6 @@ struct exec
#define ZMAGIC 0413
#define QMAGIC 0314
-/* max code+data+bss+brk space allocated to ET_DYN executables */
-#define ET_DYN_MAP_SIZE (128 * 1024 * 1024)
-
/* Necessary parameters */
#define TARGET_ELF_EXEC_PAGESIZE TARGET_PAGE_SIZE
#define TARGET_ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(TARGET_ELF_EXEC_PAGESIZE-1))
@@ -1169,7 +1166,7 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
On return: INFO values will be filled in, as necessary or available. */
static void load_elf_image(const char *image_name, int image_fd,
- struct image_info *info,
+ struct image_info *info, char **pinterp_name,
char bprm_buf[BPRM_BUF_SIZE])
{
struct elfhdr *ehdr = (struct elfhdr *)bprm_buf;
@@ -1229,6 +1226,67 @@ static void load_elf_image(const char *image_name, int image_fd,
if (load_addr == -1) {
goto exit_perror;
}
+ } else if (pinterp_name != NULL) {
+ /* This is the main executable. Make sure that the low
+ address does not conflict with MMAP_MIN_ADDR or the
+ QEMU application itself. */
+#if defined(CONFIG_USE_GUEST_BASE)
+ /*
+ * In case where user has not explicitly set the guest_base, we
+ * probe here that should we set it automatically.
+ */
+ if (!have_guest_base && !reserved_va) {
+ unsigned long host_start, real_start, host_size;
+
+ /* Round addresses to page boundaries. */
+ loaddr &= qemu_host_page_mask;
+ hiaddr = HOST_PAGE_ALIGN(hiaddr);
+
+ if (loaddr < mmap_min_addr) {
+ host_start = HOST_PAGE_ALIGN(mmap_min_addr);
+ } else {
+ host_start = loaddr;
+ if (host_start != loaddr) {
+ errmsg = "Address overflow loading ELF binary";
+ goto exit_errmsg;
+ }
+ }
+ host_size = hiaddr - loaddr;
+ while (1) {
+ /* Do not use mmap_find_vma here because that is limited to the
+ guest address space. We are going to make the
+ guest address space fit whatever we're given. */
+ real_start = (unsigned long)
+ mmap((void *)host_start, host_size, PROT_NONE,
+ MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE, -1, 0);
+ if (real_start == (unsigned long)-1) {
+ goto exit_perror;
+ }
+ if (real_start == host_start) {
+ break;
+ }
+ /* That address didn't work. Unmap and try a different one.
+ The address the host picked because is typically right at
+ the top of the host address space and leaves the guest with
+ no usable address space. Resort to a linear search. We
+ already compensated for mmap_min_addr, so this should not
+ happen often. Probably means we got unlucky and host
+ address space randomization put a shared library somewhere
+ inconvenient. */
+ munmap((void *)real_start, host_size);
+ host_start += qemu_host_page_size;
+ if (host_start == loaddr) {
+ /* Theoretically possible if host doesn't have any suitably
+ aligned areas. Normally the first mmap will fail. */
+ errmsg = "Unable to find space for application";
+ goto exit_errmsg;
+ }
+ }
+ qemu_log("Relocating guest address space from 0x"
+ TARGET_ABI_FMT_lx " to 0x%lx\n", loaddr, real_start);
+ guest_base = real_start - loaddr;
+ }
+#endif
}
load_bias = load_addr - loaddr;
@@ -1290,6 +1348,33 @@ static void load_elf_image(const char *image_name, int image_fd,
info->brk = vaddr_em;
}
}
+ } else if (eppnt->p_type == PT_INTERP && pinterp_name) {
+ char *interp_name;
+
+ if (*pinterp_name) {
+ errmsg = "Multiple PT_INTERP entries";
+ goto exit_errmsg;
+ }
+ interp_name = malloc(eppnt->p_filesz);
+ if (!interp_name) {
+ goto exit_perror;
+ }
+
+ if (eppnt->p_offset + eppnt->p_filesz <= BPRM_BUF_SIZE) {
+ memcpy(interp_name, bprm_buf + eppnt->p_offset,
+ eppnt->p_filesz);
+ } else {
+ retval = pread(image_fd, interp_name, eppnt->p_filesz,
+ eppnt->p_offset);
+ if (retval != eppnt->p_filesz) {
+ goto exit_perror;
+ }
+ }
+ if (interp_name[eppnt->p_filesz - 1] != 0) {
+ errmsg = "Invalid PT_INTERP entry";
+ goto exit_errmsg;
+ }
+ *pinterp_name = interp_name;
}
}
@@ -1336,7 +1421,7 @@ static void load_elf_interp(const char *filename, struct image_info *info,
memset(bprm_buf + retval, 0, BPRM_BUF_SIZE - retval);
}
- load_elf_image(filename, fd, info, bprm_buf);
+ load_elf_image(filename, fd, info, NULL, bprm_buf);
return;
exit_perror:
@@ -1480,291 +1565,31 @@ int load_elf_binary(struct linux_binprm * bprm, struct target_pt_regs * regs,
{
struct image_info interp_info;
struct elfhdr elf_ex;
- abi_ulong load_addr, load_bias;
- int load_addr_set = 0;
- int i;
- struct elf_phdr * elf_ppnt;
- struct elf_phdr *elf_phdata;
- abi_ulong k, elf_brk;
- int retval;
char *elf_interpreter = NULL;
- abi_ulong elf_entry;
- int status;
- abi_ulong start_code, end_code, start_data, end_data;
- abi_ulong elf_stack;
- status = 0;
- load_addr = 0;
- load_bias = 0;
- elf_ex = *((struct elfhdr *) bprm->buf); /* exec-header */
+ info->start_mmap = (abi_ulong)ELF_START_MMAP;
+ info->mmap = 0;
+ info->rss = 0;
- /* First of all, some simple consistency checks */
- if (!elf_check_ident(&elf_ex)) {
- return -ENOEXEC;
- }
- bswap_ehdr(&elf_ex);
- if (!elf_check_ehdr(&elf_ex)) {
- return -ENOEXEC;
- }
+ load_elf_image(bprm->filename, bprm->fd, info,
+ &elf_interpreter, bprm->buf);
+
+ /* ??? We need a copy of the elf header for passing to create_elf_tables.
+ If we do nothing, we'll have overwritten this when we re-use bprm->buf
+ when we load the interpreter. */
+ elf_ex = *(struct elfhdr *)bprm->buf;
bprm->p = copy_elf_strings(1, &bprm->filename, bprm->page, bprm->p);
bprm->p = copy_elf_strings(bprm->envc,bprm->envp,bprm->page,bprm->p);
bprm->p = copy_elf_strings(bprm->argc,bprm->argv,bprm->page,bprm->p);
if (!bprm->p) {
- retval = -E2BIG;
- }
-
- /* Now read in all of the header information */
- elf_phdata = (struct elf_phdr *)
- malloc(elf_ex.e_phnum * sizeof(struct elf_phdr));
- if (elf_phdata == NULL) {
- return -ENOMEM;
- }
-
- i = elf_ex.e_phnum * sizeof(struct elf_phdr);
- if (elf_ex.e_phoff + i <= BPRM_BUF_SIZE) {
- memcpy(elf_phdata, bprm->buf + elf_ex.e_phoff, i);
- } else {
- retval = pread(bprm->fd, (char *) elf_phdata, i, elf_ex.e_phoff);
- if (retval != i) {
- perror("load_elf_binary");
- exit(-1);
- }
- }
- bswap_phdr(elf_phdata, elf_ex.e_phnum);
-
- elf_brk = 0;
- elf_stack = ~((abi_ulong)0UL);
- start_code = ~((abi_ulong)0UL);
- end_code = 0;
- start_data = 0;
- end_data = 0;
-
- elf_ppnt = elf_phdata;
- for(i=0;i < elf_ex.e_phnum; i++) {
- if (elf_ppnt->p_type == PT_INTERP) {
- if (elf_ppnt->p_offset + elf_ppnt->p_filesz <= BPRM_BUF_SIZE) {
- elf_interpreter = bprm->buf + elf_ppnt->p_offset;
- } else {
- elf_interpreter = alloca(elf_ppnt->p_filesz);
- retval = pread(bprm->fd, elf_interpreter, elf_ppnt->p_filesz,
- elf_ppnt->p_offset);
- if (retval != elf_ppnt->p_filesz) {
- perror("load_elf_binary");
- exit(-1);
- }
- }
- }
- elf_ppnt++;
- }
-
- /* OK, This is the point of no return */
- info->end_data = 0;
- info->end_code = 0;
- info->start_mmap = (abi_ulong)ELF_START_MMAP;
- info->mmap = 0;
- elf_entry = (abi_ulong) elf_ex.e_entry;
-
-#if defined(CONFIG_USE_GUEST_BASE)
- /*
- * In case where user has not explicitly set the guest_base, we
- * probe here that should we set it automatically.
- */
- if (!(have_guest_base || reserved_va)) {
- /*
- * Go through ELF program header table and find the address
- * range used by loadable segments. Check that this is available on
- * the host, and if not find a suitable value for guest_base. */
- abi_ulong app_start = ~0;
- abi_ulong app_end = 0;
- abi_ulong addr;
- unsigned long host_start;
- unsigned long real_start;
- unsigned long host_size;
- for (i = 0, elf_ppnt = elf_phdata; i < elf_ex.e_phnum;
- i++, elf_ppnt++) {
- if (elf_ppnt->p_type != PT_LOAD)
- continue;
- addr = elf_ppnt->p_vaddr;
- if (addr < app_start) {
- app_start = addr;
- }
- addr += elf_ppnt->p_memsz;
- if (addr > app_end) {
- app_end = addr;
- }
- }
-
- /* If we don't have any loadable segments then something
- is very wrong. */
- assert(app_start < app_end);
-
- /* Round addresses to page boundaries. */
- app_start = app_start & qemu_host_page_mask;
- app_end = HOST_PAGE_ALIGN(app_end);
- if (app_start < mmap_min_addr) {
- host_start = HOST_PAGE_ALIGN(mmap_min_addr);
- } else {
- host_start = app_start;
- if (host_start != app_start) {
- fprintf(stderr, "qemu: Address overflow loading ELF binary\n");
- abort();
- }
- }
- host_size = app_end - app_start;
- while (1) {
- /* Do not use mmap_find_vma here because that is limited to the
- guest address space. We are going to make the
- guest address space fit whatever we're given. */
- real_start = (unsigned long)mmap((void *)host_start, host_size,
- PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE, -1, 0);
- if (real_start == (unsigned long)-1) {
- fprintf(stderr, "qemu: Virtual memory exausted\n");
- abort();
- }
- if (real_start == host_start) {
- break;
- }
- /* That address didn't work. Unmap and try a different one.
- The address the host picked because is typically
- right at the top of the host address space and leaves the
- guest with no usable address space. Resort to a linear search.
- We already compensated for mmap_min_addr, so this should not
- happen often. Probably means we got unlucky and host address
- space randomization put a shared library somewhere
- inconvenient. */
- munmap((void *)real_start, host_size);
- host_start += qemu_host_page_size;
- if (host_start == app_start) {
- /* Theoretically possible if host doesn't have any
- suitably aligned areas. Normally the first mmap will
- fail. */
- fprintf(stderr, "qemu: Unable to find space for application\n");
- abort();
- }
- }
- qemu_log("Relocating guest address space from 0x" TARGET_ABI_FMT_lx
- " to 0x%lx\n", app_start, real_start);
- guest_base = real_start - app_start;
+ fprintf(stderr, "%s: %s\n", bprm->filename, strerror(E2BIG));
+ exit(-1);
}
-#endif /* CONFIG_USE_GUEST_BASE */
/* Do this so that we can load the interpreter, if need be. We will
change some of these later */
- info->rss = 0;
bprm->p = setup_arg_pages(bprm->p, bprm, info);
- info->start_stack = bprm->p;
-
- /* Now we do a little grungy work by mmaping the ELF image into
- * the correct location in memory. At this point, we assume that
- * the image should be loaded at fixed address, not at a variable
- * address.
- */
-
- for(i = 0, elf_ppnt = elf_phdata; i < elf_ex.e_phnum; i++, elf_ppnt++) {
- int elf_prot = 0;
- int elf_flags = 0;
- abi_ulong 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 hardcoding any address */
- error = target_mmap(0, ET_DYN_MAP_SIZE,
- PROT_NONE, MAP_PRIVATE | MAP_ANON,
- -1, 0);
- if (error == -1) {
- perror("mmap");
- exit(-1);
- }
- load_bias = TARGET_ELF_PAGESTART(error - elf_ppnt->p_vaddr);
- }
-
- error = target_mmap(TARGET_ELF_PAGESTART(load_bias + elf_ppnt->p_vaddr),
- (elf_ppnt->p_filesz +
- TARGET_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)),
- elf_prot,
- (MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE),
- bprm->fd,
- (elf_ppnt->p_offset -
- TARGET_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)));
- if (error == -1) {
- perror("mmap");
- exit(-1);
- }
-
-#ifdef LOW_ELF_STACK
- if (TARGET_ELF_PAGESTART(elf_ppnt->p_vaddr) < elf_stack)
- elf_stack = TARGET_ELF_PAGESTART(elf_ppnt->p_vaddr);
-#endif
-
- 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 -
- TARGET_ELF_PAGESTART(load_bias + elf_ppnt->p_vaddr);
- load_addr += load_bias;
- }
- }
- k = elf_ppnt->p_vaddr;
- if (k < start_code)
- start_code = k;
- if (start_data < k)
- start_data = k;
- k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
- 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 = TARGET_PAGE_ALIGN(k);
- }
-
- /* If the load segment requests extra zeros (e.g. bss), map it. */
- if (elf_ppnt->p_filesz < elf_ppnt->p_memsz) {
- abi_ulong base = load_bias + elf_ppnt->p_vaddr;
- zero_bss(base + elf_ppnt->p_filesz,
- base + elf_ppnt->p_memsz, elf_prot);
- }
- }
-
- elf_entry += load_bias;
- elf_brk += load_bias;
- start_code += load_bias;
- end_code += load_bias;
- start_data += load_bias;
- end_data += load_bias;
-
- info->load_bias = load_bias;
- info->load_addr = load_addr;
- info->entry = elf_entry;
- info->start_brk = info->brk = elf_brk;
- info->end_code = end_code;
- info->start_code = start_code;
- info->start_data = start_data;
- info->end_data = end_data;
- info->personality = PER_LINUX;
-
- free(elf_phdata);
-
- if (qemu_log_enabled()) {
- load_symbols(&elf_ex, bprm->fd, load_bias);
- }
-
- close(bprm->fd);
if (elf_interpreter) {
load_elf_interp(elf_interpreter, &interp_info, bprm->buf);
@@ -1796,6 +1621,7 @@ int load_elf_binary(struct linux_binprm * bprm, struct target_pt_regs * regs,
if (elf_interpreter) {
info->load_addr = interp_info.load_addr;
info->entry = interp_info.entry;
+ free(elf_interpreter);
}
#ifdef USE_ELF_CORE_DUMP