Moving toward a single copy of the elf binary loading code.
Fill in the details of the loaded image into a struct image_info.
Adjust create_elf_tables to read from such structures instead
of from a collection of passed arguments. Don't return error
values from load_elf_interp; always exit(-1) with a message to
stderr. Collect elf_interpreter handling in load_elf_binary
to a common spot.
Signed-off-by: Richard Henderson <r...@twiddle.net>
---
linux-user/elfload.c | 341 ++++++++++++++++++++++++-------------------------
1 files changed, 167 insertions(+), 174 deletions(-)
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 2f15b9c..c58387a 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1078,11 +1078,9 @@ static void zero_bss(abi_ulong elf_bss, abi_ulong
last_bss, int prot)
}
static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
- struct elfhdr * exec,
- abi_ulong load_addr,
- abi_ulong load_bias,
- abi_ulong interp_load_addr,
- struct image_info *info)
+ struct elfhdr *exec,
+ struct image_info *info,
+ struct image_info *interp_info)
{
abi_ulong sp;
int size;
@@ -1127,13 +1125,13 @@ static abi_ulong create_elf_tables(abi_ulong p, int
argc, int envc,
NEW_AUX_ENT (AT_NULL, 0);
/* There must be exactly DLINFO_ITEMS entries here. */
- NEW_AUX_ENT(AT_PHDR, (abi_ulong)(load_addr + exec->e_phoff));
+ NEW_AUX_ENT(AT_PHDR, (abi_ulong)(info->load_addr + exec->e_phoff));
NEW_AUX_ENT(AT_PHENT, (abi_ulong)(sizeof (struct elf_phdr)));
NEW_AUX_ENT(AT_PHNUM, (abi_ulong)(exec->e_phnum));
NEW_AUX_ENT(AT_PAGESZ, (abi_ulong)(TARGET_PAGE_SIZE));
- NEW_AUX_ENT(AT_BASE, (abi_ulong)(interp_load_addr));
+ NEW_AUX_ENT(AT_BASE, (abi_ulong)(interp_info->load_addr));
NEW_AUX_ENT(AT_FLAGS, (abi_ulong)0);
- NEW_AUX_ENT(AT_ENTRY, load_bias + exec->e_entry);
+ NEW_AUX_ENT(AT_ENTRY, info->entry);
NEW_AUX_ENT(AT_UID, (abi_ulong) getuid());
NEW_AUX_ENT(AT_EUID, (abi_ulong) geteuid());
NEW_AUX_ENT(AT_GID, (abi_ulong) getgid());
@@ -1157,51 +1155,60 @@ static abi_ulong create_elf_tables(abi_ulong p, int
argc, int envc,
return sp;
}
+/* Load an ELF image into the address space.
-static abi_ulong load_elf_interp(struct elfhdr * interp_elf_ex,
- int interpreter_fd,
- abi_ulong *interp_load_addr,
- char bprm_buf[BPRM_BUF_SIZE])
+ IMAGE_NAME is the filename of the image, to use in error messages.
+ IMAGE_FD is the open file descriptor for the image.
+
+ BUFPAGE is a copy of the first page of the file; this of course
+ contains the elf file header at offset 0. It is assumed that this
+ buffer is sufficiently aligned to present no problems to the host
+ in accessing data at aligned offsets within the buffer.
+
+ 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,
+ char bprm_buf[BPRM_BUF_SIZE])
{
- struct elf_phdr *elf_phdata = NULL;
- abi_ulong load_addr, load_bias, loaddr, hiaddr;
- int retval;
- abi_ulong error;
- int i;
+ struct elfhdr *ehdr = (struct elfhdr *)bprm_buf;
+ struct elf_phdr *phdr;
+ abi_ulong load_addr, load_bias, loaddr, hiaddr, error;
+ int i, retval;
+ const char *errmsg;
- bswap_ehdr(interp_elf_ex);
- if (!elf_check_ehdr(interp_elf_ex)) {
- return ~((abi_ulong)0UL);
+ /* First of all, some simple consistency checks */
+ errmsg = "Invalid ELF image for this architecture";
+ if (!elf_check_ident(ehdr)) {
+ goto exit_errmsg;
+ }
+ bswap_ehdr(ehdr);
+ if (!elf_check_ehdr(ehdr)) {
+ goto exit_errmsg;
}
- /* Now read in all of the header information */
- elf_phdata = (struct elf_phdr *)
- malloc(sizeof(struct elf_phdr) * interp_elf_ex->e_phnum);
- if (!elf_phdata)
- return ~((abi_ulong)0UL);
-
- i = interp_elf_ex->e_phnum * sizeof(struct elf_phdr);
- if (interp_elf_ex->e_phoff + i <= BPRM_BUF_SIZE) {
- memcpy(elf_phdata, bprm_buf + interp_elf_ex->e_phoff, i);
+ i = ehdr->e_phnum * sizeof(struct elf_phdr);
+ if (ehdr->e_phoff + i <= BPRM_BUF_SIZE) {
+ phdr = (struct elf_phdr *)(bprm_buf + ehdr->e_phoff);
} else {
- retval = pread(interpreter_fd, elf_phdata, i, interp_elf_ex->e_phoff);
+ phdr = (struct elf_phdr *) alloca(i);
+ retval = pread(image_fd, phdr, i, ehdr->e_phoff);
if (retval != i) {
- perror("load_elf_interp");
- exit(-1);
+ goto exit_read;
}
}
- bswap_phdr(elf_phdata, interp_elf_ex->e_phnum);
+ bswap_phdr(phdr, ehdr->e_phnum);
/* Find the maximum size of the image and allocate an appropriate
amount of memory to handle that. */
loaddr = -1, hiaddr = 0;
- for (i = 0; i < interp_elf_ex->e_phnum; ++i) {
- if (elf_phdata[i].p_type == PT_LOAD) {
- abi_ulong a = elf_phdata[i].p_vaddr;
+ for (i = 0; i < ehdr->e_phnum; ++i) {
+ if (phdr[i].p_type == PT_LOAD) {
+ abi_ulong a = phdr[i].p_vaddr;
if (a < loaddr) {
loaddr = a;
}
- a += elf_phdata[i].p_memsz;
+ a += phdr[i].p_memsz;
if (a > hiaddr) {
hiaddr = a;
}
@@ -1209,7 +1216,7 @@ static abi_ulong load_elf_interp(struct elfhdr *
interp_elf_ex,
}
load_addr = loaddr;
- if (interp_elf_ex->e_type == ET_DYN) {
+ if (ehdr->e_type == ET_DYN) {
/* The image indicates that it can be loaded anywhere. Find a
location that can hold the memory space required. If the
image is pre-linked, LOADDR will be non-zero. Since we do
@@ -1219,14 +1226,22 @@ static abi_ulong load_elf_interp(struct elfhdr *
interp_elf_ex,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
-1, 0);
if (load_addr == -1) {
- perror("mmap");
- exit(-1);
+ goto exit_perror;
}
}
load_bias = load_addr - loaddr;
- for (i = 0; i < interp_elf_ex->e_phnum; i++) {
- struct elf_phdr *eppnt = elf_phdata + i;
+ info->load_bias = load_bias;
+ info->load_addr = load_addr;
+ info->entry = ehdr->e_entry + load_bias;
+ info->start_code = -1;
+ info->end_code = 0;
+ info->start_data = -1;
+ info->end_data = 0;
+ info->brk = 0;
+
+ for (i = 0; i < ehdr->e_phnum; i++) {
+ struct elf_phdr *eppnt = phdr + i;
if (eppnt->p_type == PT_LOAD) {
abi_ulong vaddr, vaddr_po, vaddr_ps, vaddr_ef, vaddr_em;
int elf_prot = 0;
@@ -1241,12 +1256,9 @@ static abi_ulong load_elf_interp(struct elfhdr *
interp_elf_ex,
error = target_mmap(vaddr_ps, eppnt->p_filesz + vaddr_po,
elf_prot, MAP_PRIVATE | MAP_FIXED,
- interpreter_fd, eppnt->p_offset - vaddr_po);
+ image_fd, eppnt->p_offset - vaddr_po);
if (error == -1) {
- /* Real error */
- close(interpreter_fd);
- free(elf_phdata);
- return ~((abi_ulong)0UL);
+ goto exit_perror;
}
vaddr_ef = vaddr + eppnt->p_filesz;
@@ -1256,18 +1268,79 @@ static abi_ulong load_elf_interp(struct elfhdr *
interp_elf_ex,
if (vaddr_ef < vaddr_em) {
zero_bss(vaddr_ef, vaddr_em, elf_prot);
}
+
+ /* Find the full program boundaries. */
+ if (elf_prot & PROT_EXEC) {
+ if (vaddr < info->start_code) {
+ info->start_code = vaddr;
+ }
+ if (vaddr_ef > info->end_code) {
+ info->end_code = vaddr_ef;
+ }
+ }
+ if (elf_prot & PROT_WRITE) {
+ if (vaddr < info->start_data) {
+ info->start_data = vaddr;
+ }
+ if (vaddr_ef > info->end_data) {
+ info->end_data = vaddr_ef;
+ }
+ if (vaddr_em > info->brk) {
+ info->brk = vaddr_em;
+ }
+ }
}
}
+ if (info->end_data == 0) {
+ info->start_data = info->end_code;
+ info->end_data = info->end_code;
+ info->brk = info->end_code;
+ }
+
if (qemu_log_enabled()) {
- load_symbols(interp_elf_ex, interpreter_fd, load_bias);
+ load_symbols(ehdr, image_fd, load_bias);
}
- close(interpreter_fd);
- free(elf_phdata);
+ close(image_fd);
+ return;
+
+ exit_read:
+ if (retval >= 0) {
+ errmsg = "Incomplete read of file header";
+ goto exit_errmsg;
+ }
+ exit_perror:
+ errmsg = strerror(errno);
+ exit_errmsg:
+ fprintf(stderr, "%s: %s\n", image_name, errmsg);
+ exit(-1);
+}
+
+static void load_elf_interp(const char *filename, struct image_info *info,
+ char bprm_buf[BPRM_BUF_SIZE])
+{
+ int fd, retval;
+
+ fd = open(path(filename), O_RDONLY);
+ if (fd < 0) {
+ goto exit_perror;
+ }
- *interp_load_addr = load_addr;
- return ((abi_ulong) interp_elf_ex->e_entry) + load_bias;
+ retval = read(fd, bprm_buf, BPRM_BUF_SIZE);
+ if (retval < 0) {
+ goto exit_perror;
+ }
+ if (retval < BPRM_BUF_SIZE) {
+ memset(bprm_buf + retval, 0, BPRM_BUF_SIZE - retval);
+ }
+
+ load_elf_image(filename, fd, info, bprm_buf);
+ return;
+
+ exit_perror:
+ fprintf(stderr, "%s: %s\n", filename, strerror(errno));
+ exit(-1);
}
static int symfind(const void *s0, const void *s1)
@@ -1404,26 +1477,21 @@ static void load_symbols(struct elfhdr *hdr, int fd,
abi_ulong load_bias)
int load_elf_binary(struct linux_binprm * bprm, struct target_pt_regs * regs,
struct image_info * info)
{
+ struct image_info interp_info;
struct elfhdr elf_ex;
- struct elfhdr interp_elf_ex;
- int interpreter_fd = -1; /* avoid warning */
abi_ulong load_addr, load_bias;
int load_addr_set = 0;
- unsigned char ibcs2_interpreter;
int i;
- abi_ulong mapped_addr;
struct elf_phdr * elf_ppnt;
struct elf_phdr *elf_phdata;
abi_ulong k, elf_brk;
int retval;
- char * elf_interpreter;
- abi_ulong elf_entry, interp_load_addr = 0;
+ char *elf_interpreter = NULL;
+ abi_ulong elf_entry;
int status;
abi_ulong start_code, end_code, start_data, end_data;
- abi_ulong reloc_func_desc = 0;
abi_ulong elf_stack;
- ibcs2_interpreter = 0;
status = 0;
load_addr = 0;
load_bias = 0;
@@ -1466,7 +1534,6 @@ int load_elf_binary(struct linux_binprm * bprm, struct
target_pt_regs * regs,
elf_brk = 0;
elf_stack = ~((abi_ulong)0UL);
- elf_interpreter = NULL;
start_code = ~((abi_ulong)0UL);
end_code = 0;
start_data = 0;
@@ -1475,82 +1542,21 @@ int load_elf_binary(struct linux_binprm * bprm, struct
target_pt_regs * regs,
elf_ppnt = elf_phdata;
for(i=0;i < elf_ex.e_phnum; i++) {
if (elf_ppnt->p_type == PT_INTERP) {
- if ( elf_interpreter != NULL )
- {
- free (elf_phdata);
- free(elf_interpreter);
- close(bprm->fd);
- return -EINVAL;
- }
-
- /* This is the program interpreter used for
- * shared libraries - for now assume that this
- * is an a.out format binary
- */
-
- elf_interpreter = (char *)malloc(elf_ppnt->p_filesz);
-
- if (elf_interpreter == NULL) {
- free (elf_phdata);
- close(bprm->fd);
- return -ENOMEM;
- }
-
if (elf_ppnt->p_offset + elf_ppnt->p_filesz <= BPRM_BUF_SIZE) {
- memcpy(elf_interpreter, bprm->buf + elf_ppnt->p_offset,
- elf_ppnt->p_filesz);
+ 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_binary2");
+ perror("load_elf_binary");
exit(-1);
}
}
-
- /* If the program interpreter is one of these two,
- then assume an iBCS2 image. Otherwise assume
- a native linux image. */
-
- /* JRP - Need to add X86 lib dir stuff here... */
-
- if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
- strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0) {
- ibcs2_interpreter = 1;
- }
-
- retval = open(path(elf_interpreter), O_RDONLY);
- if (retval < 0) {
- perror(elf_interpreter);
- exit(-1);
- }
- interpreter_fd = retval;
-
- retval = read(interpreter_fd, bprm->buf, BPRM_BUF_SIZE);
- if (retval < 0) {
- perror("load_elf_binary3");
- exit(-1);
- }
- if (retval < BPRM_BUF_SIZE) {
- memset(bprm->buf, 0, BPRM_BUF_SIZE - retval);
- }
-
- interp_elf_ex = *((struct elfhdr *) bprm->buf);
}
elf_ppnt++;
}
- /* Some simple consistency checks for the interpreter */
- if (elf_interpreter) {
- if (!elf_check_ident(&interp_elf_ex)) {
- free(elf_interpreter);
- free(elf_phdata);
- close(bprm->fd);
- close(interpreter_fd);
- return -ELIBBAD;
- }
- }
-
/* OK, This is the point of no return */
info->end_data = 0;
info->end_code = 0;
@@ -1648,7 +1654,6 @@ int load_elf_binary(struct linux_binprm * bprm, struct
target_pt_regs * regs,
load_bias += error -
TARGET_ELF_PAGESTART(load_bias + elf_ppnt->p_vaddr);
load_addr += load_bias;
- reloc_func_desc = load_bias;
}
}
k = elf_ppnt->p_vaddr;
@@ -1681,19 +1686,15 @@ int load_elf_binary(struct linux_binprm * bprm, struct
target_pt_regs * regs,
start_data += load_bias;
end_data += load_bias;
- if (elf_interpreter) {
- elf_entry = load_elf_interp(&interp_elf_ex, interpreter_fd,
- &interp_load_addr, bprm->buf);
- reloc_func_desc = interp_load_addr;
- free(elf_interpreter);
-
- if (elf_entry == ~((abi_ulong)0UL)) {
- printf("Unable to load interpreter\n");
- free(elf_phdata);
- exit(-1);
- return 0;
- }
- }
+ 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);
@@ -1702,46 +1703,38 @@ int load_elf_binary(struct linux_binprm * bprm, struct
target_pt_regs * regs,
}
close(bprm->fd);
- info->personality = (ibcs2_interpreter ? PER_SVR4 : PER_LINUX);
-#ifdef LOW_ELF_STACK
- info->start_stack = bprm->p = elf_stack - 4;
-#endif
- bprm->p = create_elf_tables(bprm->p,
- bprm->argc,
- bprm->envc,
- &elf_ex,
- load_addr, load_bias,
- interp_load_addr,
- info);
- info->load_addr = reloc_func_desc;
- 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->start_stack = bprm->p;
+ if (elf_interpreter) {
+ load_elf_interp(elf_interpreter, &interp_info, bprm->buf);
-#if 0
- printf("(start_brk) %x\n" , info->start_brk);
- printf("(end_code) %x\n" , info->end_code);
- printf("(start_code) %x\n" , info->start_code);
- printf("(end_data) %x\n" , info->end_data);
- printf("(start_stack) %x\n" , info->start_stack);
- printf("(brk) %x\n" , info->brk);
-#endif
+ /* If the program interpreter is one of these two, then assume
+ an iBCS2 image. Otherwise assume a native linux image. */
- if ( info->personality == PER_SVR4 )
- {
- /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
- and some applications "depend" upon this behavior.
- Since we do not have the power to recompile these, we
- emulate the SVr4 behavior. Sigh. */
- mapped_addr = target_mmap(0, qemu_host_page_size, PROT_READ |
PROT_EXEC,
- MAP_FIXED | MAP_PRIVATE, -1, 0);
+ if (strcmp(elf_interpreter, "/usr/lib/libc.so.1") == 0
+ || strcmp(elf_interpreter, "/usr/lib/ld.so.1") == 0) {
+ info->personality = PER_SVR4;
+
+ /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
+ and some applications "depend" upon this behavior. Since
+ we do not have the power to recompile these, we emulate
+ the SVr4 behavior. Sigh. */
+ target_mmap(0, qemu_host_page_size, PROT_READ | PROT_EXEC,
+ MAP_FIXED | MAP_PRIVATE, -1, 0);
+ }
}
- info->entry = elf_entry;
+ bprm->p = create_elf_tables(bprm->p, bprm->argc, bprm->envc, &elf_ex,
+ info, (elf_interpreter ? &interp_info : NULL));
+ info->start_stack = bprm->p;
+
+ /* If we have an interpreter, set that as the program's entry point.
+ Copy the load_addr as well, to help PPC64 interpret the entry
+ point as a function descriptor. Do this after creating elf tables
+ so that we copy the original program entry point into the AUXV. */
+ if (elf_interpreter) {
+ info->load_addr = interp_info.load_addr;
+ info->entry = interp_info.entry;
+ }
#ifdef USE_ELF_CORE_DUMP
bprm->core_dump = &elf_core_dump;
--
1.6.6.1
