| Message ID | 1306786278-12219-1-git-send-email-bp@alien8.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, May 31, 2011 at 12:26:55PM +0200, Ingo Molnar wrote: > > * Avi Kivity <avi@redhat.com> wrote: > > > On 05/31/2011 10:38 AM, Ingo Molnar wrote: > > >* Borislav Petkov<bp@alien8.de> wrote: > > > > > >> +++ b/arch/x86/kvm/paging_tmpl.h > > >> @@ -121,7 +121,7 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker, > > >> gva_t addr, u32 access) > > >> { > > >> pt_element_t pte; > > >> - pt_element_t __user *ptep_user; > > >> + pt_element_t __user *uninitialized_var(ptep_user); > > > > > >Note that doing this is actually actively dangerous for two reasons. > > > > > > > > > > <snip lots of good advice> > > > > > Please fix it instead. > > > > s/instead/in addition/; while all those changes are good, they are > > much too large for 3.0. Let's push the simple fix for 3.0 and > > queue the bigger refactoring to 3.1. > > Yeah, that's probably wise, this is a tricky function. So, any progress on this front? Warning is still there in -rc2. Thanks.
On 06/07/2011 10:28 AM, Borislav Petkov wrote: > So, any progress on this front? Warning is still there in -rc2. > Thanks for the reminder, applied and queued.
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 6c4dc01..9d03ad4 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -121,7 +121,7 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker, gva_t addr, u32 access) { pt_element_t pte; - pt_element_t __user *ptep_user; + pt_element_t __user *uninitialized_var(ptep_user); gfn_t table_gfn; unsigned index, pt_access, uninitialized_var(pte_access); gpa_t pte_gpa;
On 3.0-rc1 I get In file included from arch/x86/kvm/mmu.c:2856: arch/x86/kvm/paging_tmpl.h: In function ‘paging32_walk_addr_generic’: arch/x86/kvm/paging_tmpl.h:124: warning: ‘ptep_user’ may be used uninitialized in this function In file included from arch/x86/kvm/mmu.c:2852: arch/x86/kvm/paging_tmpl.h: In function ‘paging64_walk_addr_generic’: arch/x86/kvm/paging_tmpl.h:124: warning: ‘ptep_user’ may be used uninitialized in this function caused by 6e2ca7d1802bf8ed9908435e34daa116662e7790. According to Takuya Yoshikawa, ptep_user won't be used uninitialized so shut up gcc. Cc: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Link: http://lkml.kernel.org/r/20110530094604.GC21833@liondog.tnic Signed-off-by: Borislav Petkov <bp@alien8.de> --- arch/x86/kvm/paging_tmpl.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)