| Message ID | 20180523195421.180248-10-thgarnie@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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? > 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. Pavel
On Thu, May 24, 2018 at 4:03 AM Pavel Machek <pavel@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. > > 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. Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
On Thu 2018-05-24 09:35:42, Thomas Garnier wrote: > On Thu, May 24, 2018 at 4:03 AM Pavel Machek <pavel@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.
On Fri, May 25, 2018 at 2:14 AM Pavel Machek <pavel@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@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, > 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
On Fri 2018-05-25 10:00:04, Thomas Garnier wrote: > On Fri, May 25, 2018 at 2:14 AM Pavel Machek <pavel@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@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
On Tue, May 29, 2018 at 5:31 AM Pavel Machek <pavel@ucw.cz> wrote: > On Fri 2018-05-25 10:00:04, Thomas Garnier wrote: > > On Fri, May 25, 2018 at 2:14 AM Pavel Machek <pavel@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@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:. Will do. Thanks for the review. > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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 @@ -25,14 +25,14 @@ ENTRY(wakeup_long64) movw %ax, %es movw %ax, %fs movw %ax, %gs - movq saved_rsp, %rsp + movq saved_rsp(%rip), %rsp - movq saved_rbx, %rbx - movq saved_rdi, %rdi - movq saved_rsi, %rsi - movq saved_rbp, %rbp + movq saved_rbx(%rip), %rbx + movq saved_rdi(%rip), %rdi + movq saved_rsi(%rip), %rsi + movq saved_rbp(%rip), %rbp - movq saved_rip, %rax + movq saved_rip(%rip), %rax jmp *%rax ENDPROC(wakeup_long64) @@ -45,7 +45,7 @@ ENTRY(do_suspend_lowlevel) xorl %eax, %eax call save_processor_state - movq $saved_context, %rax + leaq saved_context(%rip), %rax movq %rsp, pt_regs_sp(%rax) movq %rbp, pt_regs_bp(%rax) movq %rsi, pt_regs_si(%rax) @@ -64,13 +64,14 @@ ENTRY(do_suspend_lowlevel) pushfq popq pt_regs_flags(%rax) - movq $.Lresume_point, saved_rip(%rip) + leaq .Lresume_point(%rip), %rax + movq %rax, saved_rip(%rip) - movq %rsp, saved_rsp - movq %rbp, saved_rbp - movq %rbx, saved_rbx - movq %rdi, saved_rdi - movq %rsi, saved_rsi + movq %rsp, saved_rsp(%rip) + movq %rbp, saved_rbp(%rip) + movq %rbx, saved_rbx(%rip) + movq %rdi, saved_rdi(%rip) + movq %rsi, saved_rsi(%rip) addq $8, %rsp movl $3, %edi @@ -82,7 +83,7 @@ ENTRY(do_suspend_lowlevel) .align 4 .Lresume_point: /* We don't restore %rax, it must be 0 anyway */ - movq $saved_context, %rax + leaq saved_context(%rip), %rax movq saved_context_cr4(%rax), %rbx movq %rbx, %cr4 movq saved_context_cr3(%rax), %rbx
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. Signed-off-by: Thomas Garnier <thgarnie@google.com> --- arch/x86/kernel/acpi/wakeup_64.S | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-)