Pavel Machek
2018-May-25 09:14 UTC
[PATCH v3 09/27] x86/acpi: Adapt assembly for PIE support
On Thu 2018-05-24 09:35:42, Thomas Garnier wrote:> On Thu, May 24, 2018 at 4:03 AM Pavel Machek <pavel at ucw.cz> wrote: > > > On Wed 2018-05-23 12:54:03, Thomas Garnier wrote: > > > Change the assembly code to use only relative references of symbols for > the > > > kernel to be PIE compatible. > > > > > > Position Independent Executable (PIE) support will allow to extended the > > > KASLR randomization range below the -2G memory limit. > > > What testing did this get? > > Tested boot, hibernation and performance on qemu and dedicated machine.Well, this is suspend, not hibernation code. So "sudo pm-suspend" or "echo mem > /sys/power/state" would be good way to test this. Thanks, Pavel> > > diff --git a/arch/x86/kernel/acpi/wakeup_64.S > b/arch/x86/kernel/acpi/wakeup_64.S > > > index 50b8ed0317a3..472659c0f811 100644 > > > --- a/arch/x86/kernel/acpi/wakeup_64.S > > > +++ b/arch/x86/kernel/acpi/wakeup_64.S > > > @@ -14,7 +14,7 @@ > > > * Hooray, we are in Long 64-bit mode (but still running in low > memory) > > > */ > > > ENTRY(wakeup_long64) > > > - movq saved_magic, %rax > > > + movq saved_magic(%rip), %rax > > > movq $0x123456789abcdef0, %rdx > > > cmpq %rdx, %rax > > > jne bogus_64_magic > > > Because, as comment says, this is rather tricky code. > > I agree, I think maintainers feedback is very important for this patchset.-- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 181 bytes Desc: Digital signature URL: <http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20180525/959806e5/attachment-0001.sig>
Thomas Garnier
2018-May-25 17:00 UTC
[PATCH v3 09/27] x86/acpi: Adapt assembly for PIE support
On Fri, May 25, 2018 at 2:14 AM Pavel Machek <pavel at ucw.cz> wrote:> On Thu 2018-05-24 09:35:42, Thomas Garnier wrote: > > On Thu, May 24, 2018 at 4:03 AM Pavel Machek <pavel at ucw.cz> wrote: > > > > > On Wed 2018-05-23 12:54:03, Thomas Garnier wrote: > > > > Change the assembly code to use only relative references of symbolsfor> > the > > > > kernel to be PIE compatible. > > > > > > > > Position Independent Executable (PIE) support will allow toextended the> > > > KASLR randomization range below the -2G memory limit. > > > > > What testing did this get? > > > > Tested boot, hibernation and performance on qemu and dedicated machine.> Well, this is suspend, not hibernation code.> So "sudo pm-suspend" or "echo mem > /sys/power/state" would be good > way to test this.Thanks, it worked. I added this to the testsuite I use for KASLR.> Thanks, > Pavel> > > > diff --git a/arch/x86/kernel/acpi/wakeup_64.S > > b/arch/x86/kernel/acpi/wakeup_64.S > > > > index 50b8ed0317a3..472659c0f811 100644 > > > > --- a/arch/x86/kernel/acpi/wakeup_64.S > > > > +++ b/arch/x86/kernel/acpi/wakeup_64.S > > > > @@ -14,7 +14,7 @@ > > > > * Hooray, we are in Long 64-bit mode (but still running inlow> > memory) > > > > */ > > > > ENTRY(wakeup_long64) > > > > - movq saved_magic, %rax > > > > + movq saved_magic(%rip), %rax > > > > movq $0x123456789abcdef0, %rdx > > > > cmpq %rdx, %rax > > > > jne bogus_64_magic > > > > > Because, as comment says, this is rather tricky code. > > > > I agree, I think maintainers feedback is very important for thispatchset.> -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures)http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- Thomas
Pavel Machek
2018-May-29 12:31 UTC
[PATCH v3 09/27] x86/acpi: Adapt assembly for PIE support
On Fri 2018-05-25 10:00:04, Thomas Garnier wrote:> On Fri, May 25, 2018 at 2:14 AM Pavel Machek <pavel at ucw.cz> wrote: > > > On Thu 2018-05-24 09:35:42, Thomas Garnier wrote: > > > On Thu, May 24, 2018 at 4:03 AM Pavel Machek <pavel at ucw.cz> wrote: > > > > > > > On Wed 2018-05-23 12:54:03, Thomas Garnier wrote: > > > > > Change the assembly code to use only relative references of symbols > for > > > the > > > > > kernel to be PIE compatible. > > > > > > > > > > Position Independent Executable (PIE) support will allow to > extended the > > > > > KASLR randomization range below the -2G memory limit. > > > > > > > What testing did this get? > > > > > > Tested boot, hibernation and performance on qemu and dedicated machine. > > > Well, this is suspend, not hibernation code. > > > So "sudo pm-suspend" or "echo mem > /sys/power/state" would be good > > way to test this. > > Thanks, it worked. I added this to the testsuite I use for KASLR.Thanks! You can add my Acked-by:. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 181 bytes Desc: Digital signature URL: <http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20180529/45aa5df0/attachment.sig>