* [PATCH 1/7] x86/xen: Simplify set_aliased_prot [not found] <cover.1464129798.git.luto@kernel.org> @ 2016-05-24 22:48 ` Andy Lutomirski [not found] ` <0706f1a2538e481194514197298cca6b5e3f2638.1464129798.git.luto@kernel.org> 1 sibling, 0 replies; 6+ messages in thread From: Andy Lutomirski @ 2016-05-24 22:48 UTC (permalink / raw) To: x86 Cc: Kees Cook, Brian Gerst, linux-kernel, xen-devel, David Vrabel, Jan Beulich, Borislav Petkov, Andy Lutomirski, Andrew Cooper, Boris Ostrovsky In aa1acff356bb ("x86/xen: Probe target addresses in set_aliased_prot() before the hypercall"), I added an explicit probe to work around a hypercall issue. The code can be simplified by using probe_kernel_read. Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <dvrabel@cantab.net> Cc: Jan Beulich <jbeulich@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: xen-devel <xen-devel@lists.xen.org> Signed-off-by: Andy Lutomirski <luto@kernel.org> --- arch/x86/xen/enlighten.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 6ab672233ac9..eed696c229ba 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -521,9 +521,7 @@ static void set_aliased_prot(void *v, pgprot_t prot) preempt_disable(); - pagefault_disable(); /* Avoid warnings due to being atomic. */ - __get_user(dummy, (unsigned char __user __force *)v); - pagefault_enable(); + probe_kernel_read(&dummy, (unsigned char *)v, 1); if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0)) BUG(); -- 2.5.5 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply related [flat|nested] 6+ messages in thread
[parent not found: <0706f1a2538e481194514197298cca6b5e3f2638.1464129798.git.luto@kernel.org>]
* Re: [PATCH 1/7] x86/xen: Simplify set_aliased_prot [not found] ` <0706f1a2538e481194514197298cca6b5e3f2638.1464129798.git.luto@kernel.org> @ 2016-05-25 9:38 ` Andrew Cooper 2016-05-25 9:50 ` David Vrabel ` (2 subsequent siblings) 3 siblings, 0 replies; 6+ messages in thread From: Andrew Cooper @ 2016-05-25 9:38 UTC (permalink / raw) To: Andy Lutomirski, x86 Cc: Kees Cook, Brian Gerst, linux-kernel, xen-devel, David Vrabel, Borislav Petkov, Jan Beulich, Boris Ostrovsky On 24/05/16 23:48, Andy Lutomirski wrote: > In aa1acff356bb ("x86/xen: Probe target addresses in > set_aliased_prot() before the hypercall"), I added an explicit probe > to work around a hypercall issue. The code can be simplified by > using probe_kernel_read. > > Cc: Andrew Cooper <andrew.cooper3@citrix.com> > Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> > Cc: David Vrabel <dvrabel@cantab.net> > Cc: Jan Beulich <jbeulich@suse.com> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Cc: xen-devel <xen-devel@lists.xen.org> > Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/7] x86/xen: Simplify set_aliased_prot [not found] ` <0706f1a2538e481194514197298cca6b5e3f2638.1464129798.git.luto@kernel.org> 2016-05-25 9:38 ` Andrew Cooper @ 2016-05-25 9:50 ` David Vrabel [not found] ` <57457582.9070608@citrix.com> 2016-06-11 9:34 ` [tip:x86/asm] x86/xen: Simplify set_aliased_prot() tip-bot for Andy Lutomirski 3 siblings, 0 replies; 6+ messages in thread From: David Vrabel @ 2016-05-25 9:50 UTC (permalink / raw) To: Andy Lutomirski, x86 Cc: Kees Cook, Brian Gerst, linux-kernel, xen-devel, Borislav Petkov, Jan Beulich, Andrew Cooper, Boris Ostrovsky On 24/05/16 23:48, Andy Lutomirski wrote: > In aa1acff356bb ("x86/xen: Probe target addresses in > set_aliased_prot() before the hypercall"), I added an explicit probe > to work around a hypercall issue. The code can be simplified by > using probe_kernel_read. Acked-by: David Vrabel <david.vrabel@citrix.com> David _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 6+ messages in thread
[parent not found: <57457582.9070608@citrix.com>]
* Re: [PATCH 1/7] x86/xen: Simplify set_aliased_prot [not found] ` <57457582.9070608@citrix.com> @ 2016-06-10 22:12 ` Andy Lutomirski [not found] ` <CALCETrWpo+QmdQ2n-QMojb954-oGgfHP0FBVbn6n6iR-+y6cNQ@mail.gmail.com> 1 sibling, 0 replies; 6+ messages in thread From: Andy Lutomirski @ 2016-06-10 22:12 UTC (permalink / raw) To: David Vrabel, Ingo Molnar Cc: Kees Cook, Brian Gerst, X86 ML, linux-kernel, xen-devel, Jan Beulich, Borislav Petkov, Andy Lutomirski, Andrew Cooper, Boris Ostrovsky On Wed, May 25, 2016 at 2:50 AM, David Vrabel <david.vrabel@citrix.com> wrote: > On 24/05/16 23:48, Andy Lutomirski wrote: >> In aa1acff356bb ("x86/xen: Probe target addresses in >> set_aliased_prot() before the hypercall"), I added an explicit probe >> to work around a hypercall issue. The code can be simplified by >> using probe_kernel_read. > > Acked-by: David Vrabel <david.vrabel@citrix.com> Ingo, can you apply this one patch directly to x86/asm? The rest of the series is stalled pending my fixing Borislav's review comments and, more importantly, fixing the bugs that testing it has shaken loose. This patch is a nice cleanup all by itself, though. --Andy _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 6+ messages in thread
[parent not found: <CALCETrWpo+QmdQ2n-QMojb954-oGgfHP0FBVbn6n6iR-+y6cNQ@mail.gmail.com>]
* Re: [PATCH 1/7] x86/xen: Simplify set_aliased_prot [not found] ` <CALCETrWpo+QmdQ2n-QMojb954-oGgfHP0FBVbn6n6iR-+y6cNQ@mail.gmail.com> @ 2016-06-11 9:29 ` Ingo Molnar 0 siblings, 0 replies; 6+ messages in thread From: Ingo Molnar @ 2016-06-11 9:29 UTC (permalink / raw) To: Andy Lutomirski Cc: Kees Cook, Brian Gerst, X86 ML, linux-kernel, xen-devel, Jan Beulich, Borislav Petkov, David Vrabel, Andy Lutomirski, Andrew Cooper, Boris Ostrovsky * Andy Lutomirski <luto@amacapital.net> wrote: > On Wed, May 25, 2016 at 2:50 AM, David Vrabel <david.vrabel@citrix.com> wrote: > > On 24/05/16 23:48, Andy Lutomirski wrote: > >> In aa1acff356bb ("x86/xen: Probe target addresses in > >> set_aliased_prot() before the hypercall"), I added an explicit probe > >> to work around a hypercall issue. The code can be simplified by > >> using probe_kernel_read. > > > > Acked-by: David Vrabel <david.vrabel@citrix.com> > > Ingo, can you apply this one patch directly to x86/asm? The rest of > the series is stalled pending my fixing Borislav's review comments > and, more importantly, fixing the bugs that testing it has shaken > loose. This patch is a nice cleanup all by itself, though. Ok, agreed, done. Note that I simplified it some more: - probe_kernel_read(&dummy, (unsigned char *)v, 1); + probe_kernel_read(&dummy, v, 1); ... because 'v' already has a 'void *' natural type. Thanks, Ingo _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 6+ messages in thread
* [tip:x86/asm] x86/xen: Simplify set_aliased_prot() [not found] ` <0706f1a2538e481194514197298cca6b5e3f2638.1464129798.git.luto@kernel.org> ` (2 preceding siblings ...) [not found] ` <57457582.9070608@citrix.com> @ 2016-06-11 9:34 ` tip-bot for Andy Lutomirski 3 siblings, 0 replies; 6+ messages in thread From: tip-bot for Andy Lutomirski @ 2016-06-11 9:34 UTC (permalink / raw) To: linux-tip-commits Cc: tglx, keescook, peterz, brgerst, linux-kernel, xen-devel, dvrabel, jbeulich, andrew.cooper3, bp, david.vrabel, luto, hpa, dvlasenk, boris.ostrovsky, luto, torvalds, mingo Commit-ID: 99158f10e91768d34c5004c40c42f802b719bcae Gitweb: http://git.kernel.org/tip/99158f10e91768d34c5004c40c42f802b719bcae Author: Andy Lutomirski <luto@kernel.org> AuthorDate: Tue, 24 May 2016 15:48:38 -0700 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Sat, 11 Jun 2016 11:28:11 +0200 x86/xen: Simplify set_aliased_prot() A year ago, via the following commit: aa1acff356bb ("x86/xen: Probe target addresses in set_aliased_prot() before the hypercall") I added an explicit probe to work around a hypercall issue. The code can be simplified by using probe_kernel_read(). No change in functionality. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: David Vrabel <david.vrabel@citrix.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Vrabel <dvrabel@cantab.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/0706f1a2538e481194514197298cca6b5e3f2638.1464129798.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/xen/enlighten.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 760789a..0f87db2 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -521,9 +521,7 @@ static void set_aliased_prot(void *v, pgprot_t prot) preempt_disable(); - pagefault_disable(); /* Avoid warnings due to being atomic. */ - __get_user(dummy, (unsigned char __user __force *)v); - pagefault_enable(); + probe_kernel_read(&dummy, v, 1); if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0)) BUG(); _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply related [flat|nested] 6+ messages in thread
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2016-05-24 22:48 ` [PATCH 1/7] x86/xen: Simplify set_aliased_prot Andy Lutomirski
[not found] ` <0706f1a2538e481194514197298cca6b5e3f2638.1464129798.git.luto@kernel.org>
2016-05-25 9:38 ` Andrew Cooper
2016-05-25 9:50 ` David Vrabel
[not found] ` <57457582.9070608@citrix.com>
2016-06-10 22:12 ` Andy Lutomirski
[not found] ` <CALCETrWpo+QmdQ2n-QMojb954-oGgfHP0FBVbn6n6iR-+y6cNQ@mail.gmail.com>
2016-06-11 9:29 ` Ingo Molnar
2016-06-11 9:34 ` [tip:x86/asm] x86/xen: Simplify set_aliased_prot() tip-bot for Andy Lutomirski
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