* Re: [Bugme-new] [Bug 7891] New: vdso page is no longer mapped for a.out binaries in kernel 2.6.18
[not found] <200701262240.l0QMe9aG019624@fire-2.osdl.org>
@ 2007-01-26 22:59 ` Andrew Morton
0 siblings, 0 replies; only message in thread
From: Andrew Morton @ 2007-01-26 22:59 UTC (permalink / raw)
To: Andi Kleen; +Cc: linux-kernel, bugme-daemon@kernel-bugs.osdl.org, joerg
(Please respond via reply-to-all, not via the bugzilla web interface)
On Fri, 26 Jan 2007 14:40:09 -0800
bugme-daemon@bugzilla.kernel.org wrote:
> http://bugzilla.kernel.org/show_bug.cgi?id=7891
>
> Summary: vdso page is no longer mapped for a.out binaries in
> kernel 2.6.18
> Kernel Version: 2.6.18 and later
> Status: NEW
> Severity: normal
> Owner: process_other@kernel-bugs.osdl.org
> Submitter: joerg@hydrops.han.de
>
>
> Most recent kernel where this bug did *NOT* occur: 2.6.17.14
> Distribution: vanilla kernel
> Hardware Environment: x86-32
> Software Environment: gentoo
> Problem Description: this is a 2.6.18 regression bug.
>
> In kernel 2.6.18 the vdso page is no longer mapped for a.out binaries.
> For instance a program using sleep will sigsegv on delivery of SIGALRM (to be
> precise: on return from signal handling). I tested this using a static a.out
> binary. This program does work in 2.6.17 .
>
> cat /proc/pid/smaps does show that vdso is not mapped in 2.6.18 for an a.out
> binary. I had a look at fs/binfmt_elf.c and found that the vdso pages is mapped
> using arch_setup_additional_pages from arch/i386/kernel/sysenter.c for elf.
>
> I did a test calling arch_setup_additional_pages from fs/binfmt_aout.c with
> positive result.
>
> As arch_setup_additional_pages is defined in arch/i368-asm/elf.h only, I see no
> clean way to provide a patch for fs/binfmt_aout.c.
>
> Steps to reproduce:
> Compile a simple program using sleep() to a.out binary and execute it. It will
> sigsegv on delivery of SIGALRM.
>
OK, who was it this time? Andi?
If a.out indeed needs to call arch_setup_additional_pages() then the
correct way to fix this is to rip the festering dungpile which we have now
and:
- Give i386, x86_64, powerpc and sh a new
CONFIG_ARCH_HAS_SETUP_ADDITIONAL_PAGES
- Create a new include/linux/interp.h which has:
struct linux_binprm;
#ifdef CONFIG_ARCH_HAS_SETUP_ADDITIONAL_PAGES
extern int arch_setup_additional_pages(struct linux_binprm *bprm,
int executable_stack);
#else
static inline int arch_setup_additional_pages(struct linux_binprm *bprm,
int executable_stack)
{
return 0;
}
#endif
- include <linux/interp.h> from binfmt_elf.c and binfmt_aout.c and from
all the files which implement arch_setup_additional_pages().
- Remove the #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES from binfmt_elf.c
- Add the call to arch_setup_additional_pages() in binfmt_aout.h.
^ permalink raw reply [flat|nested] only message in thread