![Christoph Hellwig](/assets/img/avatar_default.png)
Use proper ssize_t and size_t types for the return value and count argument, move the offset last and make it an in/out argument like all other read/write helpers, and make the buf argument a void pointer to get rid of lots of casts in the callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
488 lines
12 KiB
C
488 lines
12 KiB
C
/*
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* a.out loader for x86-64
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*
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* Copyright (C) 1991, 1992, 1996 Linus Torvalds
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* Hacked together by Andi Kleen
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*/
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#include <linux/module.h>
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#include <linux/time.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/a.out.h>
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#include <linux/errno.h>
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#include <linux/signal.h>
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#include <linux/string.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/stat.h>
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#include <linux/fcntl.h>
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#include <linux/ptrace.h>
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#include <linux/user.h>
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#include <linux/binfmts.h>
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#include <linux/personality.h>
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#include <linux/init.h>
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#include <linux/jiffies.h>
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#include <linux/perf_event.h>
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#include <linux/sched/task_stack.h>
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#include <linux/uaccess.h>
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#include <asm/pgalloc.h>
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#include <asm/cacheflush.h>
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#include <asm/user32.h>
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#include <asm/ia32.h>
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#undef WARN_OLD
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static int load_aout_binary(struct linux_binprm *);
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static int load_aout_library(struct file *);
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#ifdef CONFIG_COREDUMP
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static int aout_core_dump(struct coredump_params *);
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static unsigned long get_dr(int n)
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{
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struct perf_event *bp = current->thread.ptrace_bps[n];
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return bp ? bp->hw.info.address : 0;
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}
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/*
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* fill in the user structure for a core dump..
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*/
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static void dump_thread32(struct pt_regs *regs, struct user32 *dump)
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{
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u32 fs, gs;
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memset(dump, 0, sizeof(*dump));
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/* changed the size calculations - should hopefully work better. lbt */
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dump->magic = CMAGIC;
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dump->start_code = 0;
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dump->start_stack = regs->sp & ~(PAGE_SIZE - 1);
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dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
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dump->u_dsize = ((unsigned long)
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(current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
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dump->u_dsize -= dump->u_tsize;
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dump->u_debugreg[0] = get_dr(0);
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dump->u_debugreg[1] = get_dr(1);
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dump->u_debugreg[2] = get_dr(2);
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dump->u_debugreg[3] = get_dr(3);
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dump->u_debugreg[6] = current->thread.debugreg6;
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dump->u_debugreg[7] = current->thread.ptrace_dr7;
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if (dump->start_stack < 0xc0000000) {
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unsigned long tmp;
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tmp = (unsigned long) (0xc0000000 - dump->start_stack);
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dump->u_ssize = tmp >> PAGE_SHIFT;
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}
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dump->regs.ebx = regs->bx;
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dump->regs.ecx = regs->cx;
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dump->regs.edx = regs->dx;
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dump->regs.esi = regs->si;
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dump->regs.edi = regs->di;
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dump->regs.ebp = regs->bp;
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dump->regs.eax = regs->ax;
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dump->regs.ds = current->thread.ds;
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dump->regs.es = current->thread.es;
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savesegment(fs, fs);
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dump->regs.fs = fs;
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savesegment(gs, gs);
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dump->regs.gs = gs;
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dump->regs.orig_eax = regs->orig_ax;
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dump->regs.eip = regs->ip;
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dump->regs.cs = regs->cs;
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dump->regs.eflags = regs->flags;
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dump->regs.esp = regs->sp;
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dump->regs.ss = regs->ss;
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#if 1 /* FIXME */
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dump->u_fpvalid = 0;
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#else
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dump->u_fpvalid = dump_fpu(regs, &dump->i387);
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#endif
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}
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#endif
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static struct linux_binfmt aout_format = {
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.module = THIS_MODULE,
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.load_binary = load_aout_binary,
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.load_shlib = load_aout_library,
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#ifdef CONFIG_COREDUMP
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.core_dump = aout_core_dump,
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#endif
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.min_coredump = PAGE_SIZE
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};
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static int set_brk(unsigned long start, unsigned long end)
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{
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start = PAGE_ALIGN(start);
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end = PAGE_ALIGN(end);
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if (end <= start)
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return 0;
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return vm_brk(start, end - start);
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}
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#ifdef CONFIG_COREDUMP
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/*
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* These are the only things you should do on a core-file: use only these
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* macros to write out all the necessary info.
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*/
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#include <linux/coredump.h>
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#define START_DATA(u) (u.u_tsize << PAGE_SHIFT)
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#define START_STACK(u) (u.start_stack)
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/*
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* Routine writes a core dump image in the current directory.
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* Currently only a stub-function.
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*
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* Note that setuid/setgid files won't make a core-dump if the uid/gid
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* changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
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* field, which also makes sure the core-dumps won't be recursive if the
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* dumping of the process results in another error..
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*/
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static int aout_core_dump(struct coredump_params *cprm)
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{
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mm_segment_t fs;
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int has_dumped = 0;
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unsigned long dump_start, dump_size;
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struct user32 dump;
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fs = get_fs();
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set_fs(KERNEL_DS);
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has_dumped = 1;
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strncpy(dump.u_comm, current->comm, sizeof(current->comm));
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dump.u_ar0 = offsetof(struct user32, regs);
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dump.signal = cprm->siginfo->si_signo;
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dump_thread32(cprm->regs, &dump);
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/*
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* If the size of the dump file exceeds the rlimit, then see
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* what would happen if we wrote the stack, but not the data
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* area.
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*/
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if ((dump.u_dsize + dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
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dump.u_dsize = 0;
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/* Make sure we have enough room to write the stack and data areas. */
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if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
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dump.u_ssize = 0;
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/* make sure we actually have a data and stack area to dump */
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set_fs(USER_DS);
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if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_DATA(dump),
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dump.u_dsize << PAGE_SHIFT))
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dump.u_dsize = 0;
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if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_STACK(dump),
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dump.u_ssize << PAGE_SHIFT))
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dump.u_ssize = 0;
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set_fs(KERNEL_DS);
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/* struct user */
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if (!dump_emit(cprm, &dump, sizeof(dump)))
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goto end_coredump;
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/* Now dump all of the user data. Include malloced stuff as well */
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if (!dump_skip(cprm, PAGE_SIZE - sizeof(dump)))
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goto end_coredump;
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/* now we start writing out the user space info */
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set_fs(USER_DS);
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/* Dump the data area */
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if (dump.u_dsize != 0) {
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dump_start = START_DATA(dump);
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dump_size = dump.u_dsize << PAGE_SHIFT;
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if (!dump_emit(cprm, (void *)dump_start, dump_size))
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goto end_coredump;
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}
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/* Now prepare to dump the stack area */
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if (dump.u_ssize != 0) {
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dump_start = START_STACK(dump);
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dump_size = dump.u_ssize << PAGE_SHIFT;
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if (!dump_emit(cprm, (void *)dump_start, dump_size))
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goto end_coredump;
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}
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end_coredump:
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set_fs(fs);
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return has_dumped;
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}
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#endif
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/*
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* create_aout_tables() parses the env- and arg-strings in new user
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* memory and creates the pointer tables from them, and puts their
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* addresses on the "stack", returning the new stack pointer value.
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*/
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static u32 __user *create_aout_tables(char __user *p, struct linux_binprm *bprm)
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{
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u32 __user *argv, *envp, *sp;
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int argc = bprm->argc, envc = bprm->envc;
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sp = (u32 __user *) ((-(unsigned long)sizeof(u32)) & (unsigned long) p);
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sp -= envc+1;
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envp = sp;
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sp -= argc+1;
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argv = sp;
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put_user((unsigned long) envp, --sp);
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put_user((unsigned long) argv, --sp);
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put_user(argc, --sp);
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current->mm->arg_start = (unsigned long) p;
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while (argc-- > 0) {
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char c;
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put_user((u32)(unsigned long)p, argv++);
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do {
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get_user(c, p++);
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} while (c);
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}
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put_user(0, argv);
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current->mm->arg_end = current->mm->env_start = (unsigned long) p;
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while (envc-- > 0) {
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char c;
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put_user((u32)(unsigned long)p, envp++);
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do {
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get_user(c, p++);
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} while (c);
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}
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put_user(0, envp);
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current->mm->env_end = (unsigned long) p;
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return sp;
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}
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/*
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* These are the functions used to load a.out style executables and shared
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* libraries. There is no binary dependent code anywhere else.
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*/
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static int load_aout_binary(struct linux_binprm *bprm)
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{
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unsigned long error, fd_offset, rlim;
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struct pt_regs *regs = current_pt_regs();
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struct exec ex;
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int retval;
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ex = *((struct exec *) bprm->buf); /* exec-header */
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if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
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N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
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N_TRSIZE(ex) || N_DRSIZE(ex) ||
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i_size_read(file_inode(bprm->file)) <
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ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
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return -ENOEXEC;
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}
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fd_offset = N_TXTOFF(ex);
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/* Check initial limits. This avoids letting people circumvent
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* size limits imposed on them by creating programs with large
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* arrays in the data or bss.
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*/
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rlim = rlimit(RLIMIT_DATA);
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if (rlim >= RLIM_INFINITY)
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rlim = ~0;
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if (ex.a_data + ex.a_bss > rlim)
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return -ENOMEM;
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/* Flush all traces of the currently running executable */
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retval = flush_old_exec(bprm);
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if (retval)
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return retval;
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/* OK, This is the point of no return */
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set_personality(PER_LINUX);
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set_personality_ia32(false);
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setup_new_exec(bprm);
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regs->cs = __USER32_CS;
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regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
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regs->r13 = regs->r14 = regs->r15 = 0;
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current->mm->end_code = ex.a_text +
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(current->mm->start_code = N_TXTADDR(ex));
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current->mm->end_data = ex.a_data +
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(current->mm->start_data = N_DATADDR(ex));
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current->mm->brk = ex.a_bss +
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(current->mm->start_brk = N_BSSADDR(ex));
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retval = setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
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if (retval < 0)
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return retval;
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install_exec_creds(bprm);
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if (N_MAGIC(ex) == OMAGIC) {
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unsigned long text_addr, map_size;
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text_addr = N_TXTADDR(ex);
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map_size = ex.a_text+ex.a_data;
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error = vm_brk(text_addr & PAGE_MASK, map_size);
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if (error)
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return error;
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error = read_code(bprm->file, text_addr, 32,
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ex.a_text + ex.a_data);
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if ((signed long)error < 0)
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return error;
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} else {
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#ifdef WARN_OLD
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static unsigned long error_time, error_time2;
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if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
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(N_MAGIC(ex) != NMAGIC) &&
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time_after(jiffies, error_time2 + 5*HZ)) {
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printk(KERN_NOTICE "executable not page aligned\n");
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error_time2 = jiffies;
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}
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if ((fd_offset & ~PAGE_MASK) != 0 &&
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time_after(jiffies, error_time + 5*HZ)) {
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printk(KERN_WARNING
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"fd_offset is not page aligned. Please convert "
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"program: %pD\n",
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bprm->file);
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error_time = jiffies;
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}
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#endif
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if (!bprm->file->f_op->mmap || (fd_offset & ~PAGE_MASK) != 0) {
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error = vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
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if (error)
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return error;
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read_code(bprm->file, N_TXTADDR(ex), fd_offset,
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ex.a_text+ex.a_data);
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goto beyond_if;
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}
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error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
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PROT_READ | PROT_EXEC,
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MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |
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MAP_EXECUTABLE | MAP_32BIT,
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fd_offset);
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if (error != N_TXTADDR(ex))
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return error;
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error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
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PROT_READ | PROT_WRITE | PROT_EXEC,
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MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |
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MAP_EXECUTABLE | MAP_32BIT,
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fd_offset + ex.a_text);
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if (error != N_DATADDR(ex))
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return error;
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}
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beyond_if:
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error = set_brk(current->mm->start_brk, current->mm->brk);
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if (error)
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return error;
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set_binfmt(&aout_format);
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current->mm->start_stack =
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(unsigned long)create_aout_tables((char __user *)bprm->p, bprm);
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/* start thread */
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loadsegment(fs, 0);
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loadsegment(ds, __USER32_DS);
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loadsegment(es, __USER32_DS);
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load_gs_index(0);
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(regs)->ip = ex.a_entry;
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(regs)->sp = current->mm->start_stack;
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(regs)->flags = 0x200;
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(regs)->cs = __USER32_CS;
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(regs)->ss = __USER32_DS;
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regs->r8 = regs->r9 = regs->r10 = regs->r11 =
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regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
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set_fs(USER_DS);
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return 0;
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}
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static int load_aout_library(struct file *file)
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{
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unsigned long bss, start_addr, len, error;
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int retval;
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struct exec ex;
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loff_t pos = 0;
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retval = -ENOEXEC;
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error = kernel_read(file, &ex, sizeof(ex), &pos);
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if (error != sizeof(ex))
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goto out;
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/* We come in here for the regular a.out style of shared libraries */
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if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
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N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
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i_size_read(file_inode(file)) <
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ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
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goto out;
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}
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if (N_FLAGS(ex))
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goto out;
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/* For QMAGIC, the starting address is 0x20 into the page. We mask
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this off to get the starting address for the page */
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start_addr = ex.a_entry & 0xfffff000;
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if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
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#ifdef WARN_OLD
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static unsigned long error_time;
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if (time_after(jiffies, error_time + 5*HZ)) {
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printk(KERN_WARNING
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"N_TXTOFF is not page aligned. Please convert "
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"library: %pD\n",
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file);
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error_time = jiffies;
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}
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#endif
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retval = vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
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if (retval)
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goto out;
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read_code(file, start_addr, N_TXTOFF(ex),
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ex.a_text + ex.a_data);
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retval = 0;
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goto out;
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}
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/* Now use mmap to map the library into memory. */
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error = vm_mmap(file, start_addr, ex.a_text + ex.a_data,
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PROT_READ | PROT_WRITE | PROT_EXEC,
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MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_32BIT,
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N_TXTOFF(ex));
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retval = error;
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if (error != start_addr)
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goto out;
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len = PAGE_ALIGN(ex.a_text + ex.a_data);
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bss = ex.a_text + ex.a_data + ex.a_bss;
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if (bss > len) {
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retval = vm_brk(start_addr + len, bss - len);
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if (retval)
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goto out;
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}
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retval = 0;
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out:
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return retval;
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}
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static int __init init_aout_binfmt(void)
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{
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register_binfmt(&aout_format);
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return 0;
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}
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static void __exit exit_aout_binfmt(void)
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{
|
|
unregister_binfmt(&aout_format);
|
|
}
|
|
|
|
module_init(init_aout_binfmt);
|
|
module_exit(exit_aout_binfmt);
|
|
MODULE_LICENSE("GPL");
|