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Subjectexecve() fails to report errors
Hi!

Take this trivial .c program. Obviously correct.


struct foo {
char fill[1*1024*1024*1024];
};

struct foo a;

void
main(void)
{
}

Compile. Run. Segfault.

Whose fault? Kernels; it fails to corectly report not enough address
space.

Now, I do not know if this is the right fix (binfmt_elf looks
spaghetty to me) but its certainly better than it was.

Pavel

--- clean/fs/binfmt_elf.c Tue Mar 5 21:52:44 2002
+++ linux/fs/binfmt_elf.c Wed Mar 6 00:14:31 2002
@@ -79,13 +79,19 @@

#define BAD_ADDR(x) ((unsigned long)(x) > TASK_SIZE)

-static void set_brk(unsigned long start, unsigned long end)
+static int set_brk(unsigned long start, unsigned long end)
{
+ int error;
start = ELF_PAGEALIGN(start);
end = ELF_PAGEALIGN(end);
if (end <= start)
- return;
- do_brk(start, end - start);
+ return 0;
+
+ error = do_brk(start, end - start);
+ if (error!=start) {
+ return error;
+ }
+ return 0;
}


@@ -606,7 +613,9 @@
/* There was a PT_LOAD segment with p_memsz > p_filesz
before this one. Map anonymous pages, if needed,
and clear the area. */
- set_brk (elf_bss + load_bias, elf_brk + load_bias);
+ retval = set_brk (elf_bss + load_bias, elf_brk + load_bias);
+ if (retval)
+ goto out_free_dentry;
nbyte = ELF_PAGEOFFSET(elf_bss);
if (nbyte) {
nbyte = ELF_MIN_ALIGN - nbyte;
@@ -721,8 +730,7 @@
/* Calling set_brk effectively mmaps the pages that we need
* for the bss and break sections
*/
- set_brk(elf_bss, elf_brk);
-
+ retval = set_brk(elf_bss, elf_brk);
padzero(elf_bss);

#if 0
@@ -745,6 +753,7 @@
error = do_mmap(NULL, 0, 4096, PROT_READ | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE, 0);
up_write(&current->mm->mmap_sem);
+ /* FIXME: Check return from mmap! */
}

#ifdef ELF_PLAT_INIT
@@ -760,8 +769,7 @@
start_thread(regs, elf_entry, bprm->p);
if (current->ptrace & PT_PTRACED)
send_sig(SIGTRAP, current, 0);
- retval = 0;
out:
return retval;

/* error cleanup */
@@ -842,9 +852,9 @@

len = ELF_PAGESTART(elf_phdata->p_filesz + elf_phdata->p_vaddr + ELF_MIN_ALIGN - 1);
bss = elf_phdata->p_memsz + elf_phdata->p_vaddr;
- if (bss > len)
- do_brk(len, bss - len);
error = 0;
+ if (bss > len)
+ error = do_brk(len, bss - len);

out_free_ph:
kfree(elf_phdata);
--
(about SSSCA) "I don't say this lightly. However, I really think that the U.S.
no longer is classifiable as a democracy, but rather as a plutocracy." --hpa
-
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