lkml.org 
[lkml]   [2009]   [Jul]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] Return ENOEXEC, not ENOENT, if a binary's or script's interpreter doesn't exist.
On Thu, Jul 09, 2009 at 03:48:20AM -0400, Geoffrey Thomas wrote:
>If you try to execute a binary compiled for ld-linux.so.1 (libc5) on a machine
>with only ld-linux.so.2 (libc6), your shell will claim "mybinary: No such file
>or directory", even though the binary exists. The ENOENT actually applies to
>the ELF intepreter, not to the file itself. The same happens if you have a
>nonexistent interpreter in a shell script's shebang line.
>
>Give a more helpful and more expected error, "cannot execute binary file", in
>these cases.
>
>Signed-off-by: Geoffrey Thomas <geofft@mit.edu>
>Tested-by: Anders Kaseorg <andersk@mit.edu>

Well, this is arguable... ENOEXEC and ENOENT are hard to choose here,
but *personally* I agree with you according to your description.

And according to execve(2), this change breaks that documentation. If you
really want to fix this, please also update the man page.

/me is also wondering if this change will break any user-space programs?

Thank you!

>---
> fs/binfmt_elf.c | 5 ++++-
> fs/binfmt_elf_fdpic.c | 2 ++
> fs/binfmt_em86.c | 8 ++++++--
> fs/binfmt_misc.c | 5 ++++-
> fs/binfmt_script.c | 8 ++++++--
> 5 files changed, 22 insertions(+), 6 deletions(-)
>
>diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
>index b7c1603..56954e4 100644
>--- a/fs/binfmt_elf.c
>+++ b/fs/binfmt_elf.c
>@@ -685,8 +685,11 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
>
> interpreter = open_exec(elf_interpreter);
> retval = PTR_ERR(interpreter);
>- if (IS_ERR(interpreter))
>+ if (IS_ERR(interpreter)) {
>+ if (retval == -ENOENT)
>+ retval = -ENOEXEC;
> goto out_free_interp;
>+ }
>
> /*
> * If the binary is not readable then enforce
>diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
>index 20fbece..604d117 100644
>--- a/fs/binfmt_elf_fdpic.c
>+++ b/fs/binfmt_elf_fdpic.c
>@@ -232,6 +232,8 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm,
> interpreter = open_exec(interpreter_name);
> retval = PTR_ERR(interpreter);
> if (IS_ERR(interpreter)) {
>+ if (retval == -ENOENT)
>+ retval = -ENOEXEC;
> interpreter = NULL;
> goto error;
> }
>diff --git a/fs/binfmt_em86.c b/fs/binfmt_em86.c
>index 32fb00b..587e0b9 100644
>--- a/fs/binfmt_em86.c
>+++ b/fs/binfmt_em86.c
>@@ -82,8 +82,12 @@ static int load_em86(struct linux_binprm *bprm,struct pt_regs *regs)
> * space, and we don't need to copy it.
> */
> file = open_exec(interp);
>- if (IS_ERR(file))
>- return PTR_ERR(file);
>+ if (IS_ERR(file)) {
>+ if (PTR_ERR(file) == -ENOENT)
>+ return -ENOEXEC;
>+ else
>+ return PTR_ERR(file);
>+ }
>
> bprm->file = file;
>
>diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
>index c4e8353..eecf0db 100644
>--- a/fs/binfmt_misc.c
>+++ b/fs/binfmt_misc.c
>@@ -180,8 +180,11 @@ static int load_misc_binary(struct linux_binprm *bprm, struct pt_regs *regs)
>
> interp_file = open_exec (iname);
> retval = PTR_ERR (interp_file);
>- if (IS_ERR (interp_file))
>+ if (IS_ERR (interp_file)) {
>+ if (retval == -ENOENT)
>+ retval = -ENOEXEC;
> goto _error;
>+ }
>
> bprm->file = interp_file;
> if (fmt->flags & MISC_FMT_CREDENTIALS) {
>diff --git a/fs/binfmt_script.c b/fs/binfmt_script.c
>index 0834350..738446f 100644
>--- a/fs/binfmt_script.c
>+++ b/fs/binfmt_script.c
>@@ -88,8 +88,12 @@ static int load_script(struct linux_binprm *bprm,struct pt_regs *regs)
> * OK, now restart the process with the interpreter's dentry.
> */
> file = open_exec(interp);
>- if (IS_ERR(file))
>- return PTR_ERR(file);
>+ if (IS_ERR(file)) {
>+ if (PTR_ERR(file) == -ENOENT)
>+ return -ENOEXEC;
>+ else
>+ return PTR_ERR(file);
>+ }
>
> bprm->file = file;
> retval = prepare_binprm(bprm);
>--
>1.5.6.5
>
>--
>To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at http://vger.kernel.org/majordomo-info.html
>Please read the FAQ at http://www.tux.org/lkml/


\
 
 \ /
  Last update: 2009-07-10 07:19    [W:0.057 / U:0.588 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site