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bsd-user: remove a.out support
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Remove still-born a.out support. The BSDs switched from a.out to ELF 20+ years
ago. It's out of scope for bsd-user, and what little support there was would
simply wind up at a not-implemented message. Simplify the whole mess by removing
it entirely. Should future support be required, it would be better to start from
scratch.

Signed-off-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
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bsdimp committed Sep 10, 2021
1 parent 7ee0986 commit ffa0366
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Showing 3 changed files with 21 additions and 95 deletions.
9 changes: 1 addition & 8 deletions bsd-user/bsdload.c
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Original file line number Diff line number Diff line change
Expand Up @@ -98,7 +98,7 @@ static int prepare_binprm(struct bsd_binprm *bprm)

/* Construct the envp and argv tables on the target stack. */
abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
abi_ulong stringp, int push_ptr)
abi_ulong stringp)
{
int n = sizeof(abi_ulong);
abi_ulong envp;
Expand All @@ -108,13 +108,6 @@ abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
envp = sp;
sp -= (argc + 1) * n;
argv = sp;
if (push_ptr) {
/* FIXME - handle put_user() failures */
sp -= n;
put_user_ual(envp, sp);
sp -= n;
put_user_ual(argv, sp);
}
sp -= n;
/* FIXME - handle put_user() failures */
put_user_ual(argc, sp);
Expand Down
105 changes: 19 additions & 86 deletions bsd-user/elfload.c
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Original file line number Diff line number Diff line change
Expand Up @@ -52,25 +52,6 @@

#include "elf.h"

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

/* max code+data+bss space allocated to elf interpreter */
#define INTERP_MAP_SIZE (32 * 1024 * 1024)

Expand All @@ -82,19 +63,13 @@ struct exec
#define TARGET_ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(TARGET_ELF_EXEC_PAGESIZE - 1))
#define TARGET_ELF_PAGEOFFSET(_v) ((_v) & (TARGET_ELF_EXEC_PAGESIZE - 1))

#define INTERPRETER_NONE 0
#define INTERPRETER_AOUT 1
#define INTERPRETER_ELF 2

#define DLINFO_ITEMS 12

static inline void memcpy_fromfs(void *to, const void *from, unsigned long n)
{
memcpy(to, from, n);
}

static int load_aout_interp(void *exptr, int interp_fd);

#ifdef BSWAP_NEEDED
static void bswap_ehdr(struct elfhdr *ehdr)
{
Expand Down Expand Up @@ -300,7 +275,7 @@ 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, int ibcs,
abi_ulong interp_load_addr,
struct image_info *info)
{
abi_ulong sp;
Expand Down Expand Up @@ -330,7 +305,7 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
size += DLINFO_ARCH_ITEMS * 2;
#endif
size += envc + argc + 2;
size += (!ibcs ? 3 : 1); /* argc itself */
size += 1; /* argc itself */
size *= n;
if (size & 15)
sp -= 16 - (size & 15);
Expand Down Expand Up @@ -370,7 +345,7 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
#endif
#undef NEW_AUX_ENT

sp = loader_build_argptr(envc, argc, sp, p, !ibcs);
sp = loader_build_argptr(envc, argc, sp, p);
return sp;
}

Expand Down Expand Up @@ -432,7 +407,7 @@ static abi_ulong load_elf_interp(struct elfhdr *interp_elf_ex,
if (retval < 0) {
perror("load_elf_interp");
exit(-1);
free (elf_phdata);
free(elf_phdata);
return retval;
}
#ifdef BSWAP_NEEDED
Expand Down Expand Up @@ -685,11 +660,9 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
{
struct elfhdr elf_ex;
struct elfhdr interp_elf_ex;
struct exec interp_ex;
int interpreter_fd = -1; /* avoid warning */
abi_ulong load_addr, load_bias;
int load_addr_set = 0;
unsigned int interpreter_type = INTERPRETER_NONE;
int i;
struct elf_phdr * elf_ppnt;
struct elf_phdr *elf_phdata;
Expand All @@ -702,7 +675,6 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
#ifdef LOW_ELF_STACK
abi_ulong elf_stack = ~((abi_ulong)0UL);
#endif
char passed_fileno[6];

load_addr = 0;
load_bias = 0;
Expand Down Expand Up @@ -760,7 +732,6 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
end_code = 0;
start_data = 0;
end_data = 0;
interp_ex.a_info = 0;

for (i = 0;i < elf_ex.e_phnum; i++) {
if (elf_ppnt->p_type == PT_INTERP) {
Expand Down Expand Up @@ -813,7 +784,6 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
}
}
if (retval >= 0) {
interp_ex = *((struct exec *) bprm->buf); /* aout exec-header */
interp_elf_ex = *((struct elfhdr *) bprm->buf); /* elf exec-header */
}
if (retval < 0) {
Expand All @@ -830,20 +800,8 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,

/* Some simple consistency checks for the interpreter */
if (elf_interpreter) {
interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;

/* Now figure out which format our binary is */
if ((N_MAGIC(interp_ex) != OMAGIC) && (N_MAGIC(interp_ex) != ZMAGIC) &&
(N_MAGIC(interp_ex) != QMAGIC)) {
interpreter_type = INTERPRETER_ELF;
}

if (interp_elf_ex.e_ident[0] != 0x7f ||
strncmp((char *)&interp_elf_ex.e_ident[1], "ELF", 3) != 0) {
interpreter_type &= ~INTERPRETER_ELF;
}

if (!interpreter_type) {
strncmp((char *)&interp_elf_ex.e_ident[1], "ELF", 3) != 0) {
free(elf_interpreter);
free(elf_phdata);
close(bprm->fd);
Expand All @@ -854,24 +812,11 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
/* OK, we are done with that, now set up the arg stuff,
and then start this sucker up */

{
char *passed_p;

if (interpreter_type == INTERPRETER_AOUT) {
snprintf(passed_fileno, sizeof(passed_fileno), "%d", bprm->fd);
passed_p = passed_fileno;

if (elf_interpreter) {
bprm->p = copy_elf_strings(1, &passed_p, bprm->page, bprm->p);
bprm->argc++;
}
}
if (!bprm->p) {
free(elf_interpreter);
free(elf_phdata);
close(bprm->fd);
return -E2BIG;
}
if (!bprm->p) {
free(elf_interpreter);
free(elf_phdata);
close(bprm->fd);
return -E2BIG;
}

/* OK, This is the point of no return */
Expand Down Expand Up @@ -997,13 +942,8 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
end_data += load_bias;

if (elf_interpreter) {
if (interpreter_type & 1) {
elf_entry = load_aout_interp(&interp_ex, interpreter_fd);
}
else if (interpreter_type & 2) {
elf_entry = load_elf_interp(&interp_elf_ex, interpreter_fd,
&interp_load_addr);
}
elf_entry = load_elf_interp(&interp_elf_ex, interpreter_fd,
&interp_load_addr);
reloc_func_desc = interp_load_addr;

close(interpreter_fd);
Expand All @@ -1022,19 +962,18 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
if (qemu_log_enabled())
load_symbols(&elf_ex, bprm->fd);

if (interpreter_type != INTERPRETER_AOUT) close(bprm->fd);
close(bprm->fd);

#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,
(interpreter_type == INTERPRETER_AOUT ? 0 : 1),
info);
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;
Expand Down Expand Up @@ -1063,12 +1002,6 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
return 0;
}

static int load_aout_interp(void *exptr, int interp_fd)
{
printf("a.out interpreter not yet supported\n");
return(0);
}

void do_init_thread(struct target_pt_regs *regs, struct image_info *infop)
{
init_thread(regs, infop);
Expand Down
2 changes: 1 addition & 1 deletion bsd-user/qemu.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -129,7 +129,7 @@ struct bsd_binprm {

void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
abi_ulong stringp, int push_ptr);
abi_ulong stringp);
int loader_exec(const char *filename, char **argv, char **envp,
struct target_pt_regs *regs, struct image_info *infop,
struct bsd_binprm *bprm);
Expand Down

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