From patchwork Thu Apr 5 00:15:49 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [Oneiric/SRU] UBUNTU: SAUCE: (no-up) Reinstate missing hunk from nx emulation Date: Wed, 04 Apr 2012 14:15:49 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 150830 Message-Id: <1333584949-1361-1-git-send-email-herton.krzesinski@canonical.com> To: kernel-team@lists.ubuntu.com From: Herton Ronaldo Krzesinski Recently with kernel 3.0.0-18.31, we started to get several bug reports of userspace crashes on launchpad, happening on i386 installs. After reproducing the issue and doing a bisect, we detected that the breakage started with commit 1d43fea ("i387: do not preload FPU state at task switch time"). Looking at that commit, turns out that our application of that change accidentaly removed one piece of i386 NX emulation patch, added with commit 775e6e8 ("UBUNTU: ubuntu: nx-emu - i386: NX emulation"). This adds back the section of code wrongly removed, verified here it fixes the bug as well. BugLink: http://bugs.launchpad.net/bugs/972821 Signed-off-by: Herton Ronaldo Krzesinski --- arch/x86/kernel/process_32.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 98f78e8..2d73f7d 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -307,6 +307,9 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) fpu = switch_fpu_prepare(prev_p, next_p); + if (next_p->mm) + load_user_cs_desc(cpu, next_p->mm); + /* * Reload esp0. */