diff options
| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2007-05-02 19:27:12 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2007-05-02 19:27:12 +0200 |
| commit | 1dbf527c51c6c20c19869c8125cb5b87c3d09506 (patch) | |
| tree | ab480b3eff886e54c6d3c881936f046599e7ea61 /Documentation/kernel-parameters.txt | |
| parent | d4f7a2c18e59e0304a1c733589ce14fc02fec1bd (diff) | |
[PATCH] i386: Make COMPAT_VDSO runtime selectable.
Now that relocation of the VDSO for COMPAT_VDSO users is done at
runtime rather than compile time, it is possible to enable/disable
compat mode at runtime.
This patch allows you to enable COMPAT_VDSO mode with "vdso=2" on the
kernel command line, or via sysctl. (Switching on a running system
shouldn't be done lightly; any process which was relying on the compat
VDSO will be upset if it goes away.)
The COMPAT_VDSO config option still exists, but if enabled it just
makes vdso_enabled default to VDSO_COMPAT.
+From: Hugh Dickins <hugh@veritas.com>
Fix oops from i386-make-compat_vdso-runtime-selectable.patch.
Even mingetty at system startup finds it easy to trigger an oops
while reading /proc/PID/maps: though it has a good hold on the mm
itself, that cannot stop exit_mm() from resetting tsk->mm to NULL.
(It is usually show_map()'s call to get_gate_vma() which oopses,
and I expect we could change that to check priv->tail_vma instead;
but no matter, even m_start()'s call just after get_task_mm() is racy.)
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Zachary Amsden <zach@vmware.com>
Cc: "Jan Beulich" <JBeulich@novell.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 84c3bd05c63..4287696f18d 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1820,6 +1820,7 @@ and is between 256 and 4096 characters. It is defined in the file [USBHID] The interval which mice are to be polled at. vdso= [IA-32,SH] + vdso=2: enable compat VDSO (default with COMPAT_VDSO) vdso=1: enable VDSO (default) vdso=0: disable VDSO mapping |