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[RESEND PATCH] arch: arm64: set __nocfi on swsusp_arch_resume

zhaoyang.huang posted 1 patch 2 weeks, 5 days ago
There is a newer version of this series
arch/arm64/kernel/hibernate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
[RESEND PATCH] arch: arm64: set __nocfi on swsusp_arch_resume
Posted by zhaoyang.huang 2 weeks, 5 days ago 
From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>

A DABT is reported[1] on an android based system when resume from hiberate,
which is root caused as CFI will plant stub code[2] to verify the
swsusp_arch_suspend_exit's authentication, where the hash value is stored
before the page that alloced by create_safe_exec_page. We also have
tried to copy the hash value together with the function but get failed since
the value is not on the desired position(src_start - 4). So we solve
this issue by setting __nocfi on swsusp_arch_resume and it works.

[1]
[   22.991934][    T1] Unable to handle kernel paging request at virtual address 0000000109170ffc
[   22.991934][    T1] Mem abort info:
[   22.991934][    T1]   ESR = 0x0000000096000007
[   22.991934][    T1]   EC = 0x25: DABT (current EL), IL = 32 bits
[   22.991934][    T1]   SET = 0, FnV = 0
[   22.991934][    T1]   EA = 0, S1PTW = 0
[   22.991934][    T1]   FSC = 0x07: level 3 translation fault
[   22.991934][    T1] Data abort info:
[   22.991934][    T1]   ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000
[   22.991934][    T1]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[   22.991934][    T1]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[   22.991934][    T1] [0000000109170ffc] user address but active_mm is swapper
[   22.991934][    T1] Internal error: Oops: 0000000096000007 [#1] PREEMPT SMP
[   22.991934][    T1] Dumping ftrace buffer:
[   22.991934][    T1]    (ftrace buffer empty)
[   22.991934][    T1] Modules linked in:
[   22.991934][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.6.98-android15-8-g0b1d2aee7fc3-dirty-4k #1 688c7060a825a3ac418fe53881730b355915a419
[   22.991934][    T1] Hardware name: Unisoc UMS9360-base Board (DT)
[   22.991934][    T1] pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   22.991934][    T1] pc : swsusp_arch_resume+0x2ac/0x344
[   22.991934][    T1] lr : swsusp_arch_resume+0x294/0x344
[   22.991934][    T1] sp : ffffffc08006b960
[   22.991934][    T1] x29: ffffffc08006b9c0 x28: 0000000000000000 x27: 0000000000000000
[   22.991934][    T1] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000820
[   22.991934][    T1] x23: ffffffd0817e3000 x22: ffffffd0817e3000 x21: 0000000000000000
[   22.991934][    T1] x20: ffffff8089171000 x19: ffffffd08252c8c8 x18: ffffffc080061058
[   22.991934][    T1] x17: 00000000529c6ef0 x16: 00000000529c6ef0 x15: 0000000000000004
[   22.991934][    T1] x14: ffffff8178c88000 x13: 0000000000000006 x12: 0000000000000000
[   22.991934][    T1] x11: 0000000000000015 x10: 0000000000000001 x9 : ffffffd082533000
[   22.991934][    T1] x8 : 0000000109171000 x7 : 205b5d3433393139 x6 : 392e32322020205b
[   22.991934][    T1] x5 : 000000010916f000 x4 : 000000008164b000 x3 : ffffff808a4e0530
[   22.991934][    T1] x2 : ffffffd08058e784 x1 : 0000000082326000 x0 : 000000010a283000
[   22.991934][    T1] Call trace:
[   22.991934][    T1]  swsusp_arch_resume+0x2ac/0x344
[   22.991934][    T1]  hibernation_restore+0x158/0x18c
[   22.991934][    T1]  load_image_and_restore+0xb0/0xec
[   22.991934][    T1]  software_resume+0xf4/0x19c
[   22.991934][    T1]  software_resume_initcall+0x34/0x78
[   22.991934][    T1]  do_one_initcall+0xe8/0x370
[   22.991934][    T1]  do_initcall_level+0xc8/0x19c
[   22.991934][    T1]  do_initcalls+0x70/0xc0
[   22.991934][    T1]  do_basic_setup+0x1c/0x28
[   22.991934][    T1]  kernel_init_freeable+0xe0/0x148
[   22.991934][    T1]  kernel_init+0x20/0x1a8
[   22.991934][    T1]  ret_from_fork+0x10/0x20
[   22.991934][    T1] Code: a9400a61 f94013e0 f9438923 f9400a64 (b85fc110)

[2]
0xffffffd08064a878 <swsusp_arch_resume+596>:	mov	x0, x24
0xffffffd08064a87c <swsusp_arch_resume+600>:	mov	x1, x20
0xffffffd08064a880 <swsusp_arch_resume+604>:	mov	x2, x21
0xffffffd08064a884 <swsusp_arch_resume+608>:	mov	x3, x22
0xffffffd08064a888 <swsusp_arch_resume+612>:	mov	x4, x23
0xffffffd08064a88c <swsusp_arch_resume+616>:	ldur	w16, [x25, #-4]
0xffffffd08064a890 <swsusp_arch_resume+620>:	movk	w17, #0x5d7b
0xffffffd08064a894 <swsusp_arch_resume+624>:	movk	w17, #0xb6ad, lsl #16
0xffffffd08064a898 <swsusp_arch_resume+628>:	cmp	w16, w17
0xffffffd08064a89c <swsusp_arch_resume+632>:	b.eq	0xffffffd08064a8a4 <swsusp_arch_resume+640>  // b.none
0xffffffd08064a8a0 <swsusp_arch_resume+636>:	brk	#0x8239
0xffffffd08064a8a4 <swsusp_arch_resume+640>:	blr	x25

co_developed-by: Jeson Gao <jeson.gao@unisoc.com>
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
---
 arch/arm64/kernel/hibernate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 18749e9a6c2d..9717568518ba 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -402,7 +402,7 @@ int swsusp_arch_suspend(void)
  * Memory allocated by get_safe_page() will be dealt with by the hibernate code,
  * we don't need to free it here.
  */
-int swsusp_arch_resume(void)
+int __nocfi swsusp_arch_resume(void)
 {
 	int rc;
 	void *zero_page;
-- 
2.25.1
Re: [RESEND PATCH] arch: arm64: set __nocfi on swsusp_arch_resume
Posted by Will Deacon 2 weeks, 3 days ago 
On Tue, Jan 20, 2026 at 02:06:19PM +0800, zhaoyang.huang wrote:
> From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> 
> A DABT is reported[1] on an android based system when resume from hiberate,
> which is root caused as CFI will plant stub code[2] to verify the
> swsusp_arch_suspend_exit's authentication, where the hash value is stored
> before the page that alloced by create_safe_exec_page. We also have
> tried to copy the hash value together with the function but get failed since
> the value is not on the desired position(src_start - 4). So we solve
> this issue by setting __nocfi on swsusp_arch_resume and it works.
> 
> [1]
> [   22.991934][    T1] Unable to handle kernel paging request at virtual address 0000000109170ffc
> [   22.991934][    T1] Mem abort info:
> [   22.991934][    T1]   ESR = 0x0000000096000007
> [   22.991934][    T1]   EC = 0x25: DABT (current EL), IL = 32 bits
> [   22.991934][    T1]   SET = 0, FnV = 0
> [   22.991934][    T1]   EA = 0, S1PTW = 0
> [   22.991934][    T1]   FSC = 0x07: level 3 translation fault
> [   22.991934][    T1] Data abort info:
> [   22.991934][    T1]   ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000
> [   22.991934][    T1]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> [   22.991934][    T1]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [   22.991934][    T1] [0000000109170ffc] user address but active_mm is swapper
> [   22.991934][    T1] Internal error: Oops: 0000000096000007 [#1] PREEMPT SMP
> [   22.991934][    T1] Dumping ftrace buffer:
> [   22.991934][    T1]    (ftrace buffer empty)
> [   22.991934][    T1] Modules linked in:
> [   22.991934][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.6.98-android15-8-g0b1d2aee7fc3-dirty-4k #1 688c7060a825a3ac418fe53881730b355915a419
> [   22.991934][    T1] Hardware name: Unisoc UMS9360-base Board (DT)
> [   22.991934][    T1] pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [   22.991934][    T1] pc : swsusp_arch_resume+0x2ac/0x344
> [   22.991934][    T1] lr : swsusp_arch_resume+0x294/0x344
> [   22.991934][    T1] sp : ffffffc08006b960
> [   22.991934][    T1] x29: ffffffc08006b9c0 x28: 0000000000000000 x27: 0000000000000000
> [   22.991934][    T1] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000820
> [   22.991934][    T1] x23: ffffffd0817e3000 x22: ffffffd0817e3000 x21: 0000000000000000
> [   22.991934][    T1] x20: ffffff8089171000 x19: ffffffd08252c8c8 x18: ffffffc080061058
> [   22.991934][    T1] x17: 00000000529c6ef0 x16: 00000000529c6ef0 x15: 0000000000000004
> [   22.991934][    T1] x14: ffffff8178c88000 x13: 0000000000000006 x12: 0000000000000000
> [   22.991934][    T1] x11: 0000000000000015 x10: 0000000000000001 x9 : ffffffd082533000
> [   22.991934][    T1] x8 : 0000000109171000 x7 : 205b5d3433393139 x6 : 392e32322020205b
> [   22.991934][    T1] x5 : 000000010916f000 x4 : 000000008164b000 x3 : ffffff808a4e0530
> [   22.991934][    T1] x2 : ffffffd08058e784 x1 : 0000000082326000 x0 : 000000010a283000
> [   22.991934][    T1] Call trace:
> [   22.991934][    T1]  swsusp_arch_resume+0x2ac/0x344
> [   22.991934][    T1]  hibernation_restore+0x158/0x18c
> [   22.991934][    T1]  load_image_and_restore+0xb0/0xec
> [   22.991934][    T1]  software_resume+0xf4/0x19c
> [   22.991934][    T1]  software_resume_initcall+0x34/0x78
> [   22.991934][    T1]  do_one_initcall+0xe8/0x370
> [   22.991934][    T1]  do_initcall_level+0xc8/0x19c
> [   22.991934][    T1]  do_initcalls+0x70/0xc0
> [   22.991934][    T1]  do_basic_setup+0x1c/0x28
> [   22.991934][    T1]  kernel_init_freeable+0xe0/0x148
> [   22.991934][    T1]  kernel_init+0x20/0x1a8
> [   22.991934][    T1]  ret_from_fork+0x10/0x20
> [   22.991934][    T1] Code: a9400a61 f94013e0 f9438923 f9400a64 (b85fc110)
> 
> [2]
> 0xffffffd08064a878 <swsusp_arch_resume+596>:	mov	x0, x24
> 0xffffffd08064a87c <swsusp_arch_resume+600>:	mov	x1, x20
> 0xffffffd08064a880 <swsusp_arch_resume+604>:	mov	x2, x21
> 0xffffffd08064a884 <swsusp_arch_resume+608>:	mov	x3, x22
> 0xffffffd08064a888 <swsusp_arch_resume+612>:	mov	x4, x23
> 0xffffffd08064a88c <swsusp_arch_resume+616>:	ldur	w16, [x25, #-4]
> 0xffffffd08064a890 <swsusp_arch_resume+620>:	movk	w17, #0x5d7b
> 0xffffffd08064a894 <swsusp_arch_resume+624>:	movk	w17, #0xb6ad, lsl #16
> 0xffffffd08064a898 <swsusp_arch_resume+628>:	cmp	w16, w17
> 0xffffffd08064a89c <swsusp_arch_resume+632>:	b.eq	0xffffffd08064a8a4 <swsusp_arch_resume+640>  // b.none
> 0xffffffd08064a8a0 <swsusp_arch_resume+636>:	brk	#0x8239
> 0xffffffd08064a8a4 <swsusp_arch_resume+640>:	blr	x25
> 
> co_developed-by: Jeson Gao <jeson.gao@unisoc.com>

This should be "Co-developed-by:" and you will also need Jeson's
Signed-off-by line in addition to your own.

> Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> ---
>  arch/arm64/kernel/hibernate.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
> index 18749e9a6c2d..9717568518ba 100644
> --- a/arch/arm64/kernel/hibernate.c
> +++ b/arch/arm64/kernel/hibernate.c
> @@ -402,7 +402,7 @@ int swsusp_arch_suspend(void)
>   * Memory allocated by get_safe_page() will be dealt with by the hibernate code,
>   * we don't need to free it here.
>   */
> -int swsusp_arch_resume(void)
> +int __nocfi swsusp_arch_resume(void)
>  {
>  	int rc;
>  	void *zero_page;

Why does is the '__nocfi' annotation here rather than on the
'hibernate_exit' pointer?

Will
Re: [RESEND PATCH] arch: arm64: set __nocfi on swsusp_arch_resume
Posted by Zhaoyang Huang 2 weeks, 3 days ago 
On Thu, Jan 22, 2026 at 6:32 PM Will Deacon <will@kernel.org> wrote:
>
> On Tue, Jan 20, 2026 at 02:06:19PM +0800, zhaoyang.huang wrote:
> > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> >
> > A DABT is reported[1] on an android based system when resume from hiberate,
> > which is root caused as CFI will plant stub code[2] to verify the
> > swsusp_arch_suspend_exit's authentication, where the hash value is stored
> > before the page that alloced by create_safe_exec_page. We also have
> > tried to copy the hash value together with the function but get failed since
> > the value is not on the desired position(src_start - 4). So we solve
> > this issue by setting __nocfi on swsusp_arch_resume and it works.
> >
> > [1]
> > [   22.991934][    T1] Unable to handle kernel paging request at virtual address 0000000109170ffc
> > [   22.991934][    T1] Mem abort info:
> > [   22.991934][    T1]   ESR = 0x0000000096000007
> > [   22.991934][    T1]   EC = 0x25: DABT (current EL), IL = 32 bits
> > [   22.991934][    T1]   SET = 0, FnV = 0
> > [   22.991934][    T1]   EA = 0, S1PTW = 0
> > [   22.991934][    T1]   FSC = 0x07: level 3 translation fault
> > [   22.991934][    T1] Data abort info:
> > [   22.991934][    T1]   ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000
> > [   22.991934][    T1]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> > [   22.991934][    T1]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> > [   22.991934][    T1] [0000000109170ffc] user address but active_mm is swapper
> > [   22.991934][    T1] Internal error: Oops: 0000000096000007 [#1] PREEMPT SMP
> > [   22.991934][    T1] Dumping ftrace buffer:
> > [   22.991934][    T1]    (ftrace buffer empty)
> > [   22.991934][    T1] Modules linked in:
> > [   22.991934][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.6.98-android15-8-g0b1d2aee7fc3-dirty-4k #1 688c7060a825a3ac418fe53881730b355915a419
> > [   22.991934][    T1] Hardware name: Unisoc UMS9360-base Board (DT)
> > [   22.991934][    T1] pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> > [   22.991934][    T1] pc : swsusp_arch_resume+0x2ac/0x344
> > [   22.991934][    T1] lr : swsusp_arch_resume+0x294/0x344
> > [   22.991934][    T1] sp : ffffffc08006b960
> > [   22.991934][    T1] x29: ffffffc08006b9c0 x28: 0000000000000000 x27: 0000000000000000
> > [   22.991934][    T1] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000820
> > [   22.991934][    T1] x23: ffffffd0817e3000 x22: ffffffd0817e3000 x21: 0000000000000000
> > [   22.991934][    T1] x20: ffffff8089171000 x19: ffffffd08252c8c8 x18: ffffffc080061058
> > [   22.991934][    T1] x17: 00000000529c6ef0 x16: 00000000529c6ef0 x15: 0000000000000004
> > [   22.991934][    T1] x14: ffffff8178c88000 x13: 0000000000000006 x12: 0000000000000000
> > [   22.991934][    T1] x11: 0000000000000015 x10: 0000000000000001 x9 : ffffffd082533000
> > [   22.991934][    T1] x8 : 0000000109171000 x7 : 205b5d3433393139 x6 : 392e32322020205b
> > [   22.991934][    T1] x5 : 000000010916f000 x4 : 000000008164b000 x3 : ffffff808a4e0530
> > [   22.991934][    T1] x2 : ffffffd08058e784 x1 : 0000000082326000 x0 : 000000010a283000
> > [   22.991934][    T1] Call trace:
> > [   22.991934][    T1]  swsusp_arch_resume+0x2ac/0x344
> > [   22.991934][    T1]  hibernation_restore+0x158/0x18c
> > [   22.991934][    T1]  load_image_and_restore+0xb0/0xec
> > [   22.991934][    T1]  software_resume+0xf4/0x19c
> > [   22.991934][    T1]  software_resume_initcall+0x34/0x78
> > [   22.991934][    T1]  do_one_initcall+0xe8/0x370
> > [   22.991934][    T1]  do_initcall_level+0xc8/0x19c
> > [   22.991934][    T1]  do_initcalls+0x70/0xc0
> > [   22.991934][    T1]  do_basic_setup+0x1c/0x28
> > [   22.991934][    T1]  kernel_init_freeable+0xe0/0x148
> > [   22.991934][    T1]  kernel_init+0x20/0x1a8
> > [   22.991934][    T1]  ret_from_fork+0x10/0x20
> > [   22.991934][    T1] Code: a9400a61 f94013e0 f9438923 f9400a64 (b85fc110)
> >
> > [2]
> > 0xffffffd08064a878 <swsusp_arch_resume+596>:  mov     x0, x24
> > 0xffffffd08064a87c <swsusp_arch_resume+600>:  mov     x1, x20
> > 0xffffffd08064a880 <swsusp_arch_resume+604>:  mov     x2, x21
> > 0xffffffd08064a884 <swsusp_arch_resume+608>:  mov     x3, x22
> > 0xffffffd08064a888 <swsusp_arch_resume+612>:  mov     x4, x23
> > 0xffffffd08064a88c <swsusp_arch_resume+616>:  ldur    w16, [x25, #-4]
> > 0xffffffd08064a890 <swsusp_arch_resume+620>:  movk    w17, #0x5d7b
> > 0xffffffd08064a894 <swsusp_arch_resume+624>:  movk    w17, #0xb6ad, lsl #16
> > 0xffffffd08064a898 <swsusp_arch_resume+628>:  cmp     w16, w17
> > 0xffffffd08064a89c <swsusp_arch_resume+632>:  b.eq    0xffffffd08064a8a4 <swsusp_arch_resume+640>  // b.none
> > 0xffffffd08064a8a0 <swsusp_arch_resume+636>:  brk     #0x8239
> > 0xffffffd08064a8a4 <swsusp_arch_resume+640>:  blr     x25
> >
> > co_developed-by: Jeson Gao <jeson.gao@unisoc.com>
>
> This should be "Co-developed-by:" and you will also need Jeson's
> Signed-off-by line in addition to your own.
ok
>
> > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> > ---
> >  arch/arm64/kernel/hibernate.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
> > index 18749e9a6c2d..9717568518ba 100644
> > --- a/arch/arm64/kernel/hibernate.c
> > +++ b/arch/arm64/kernel/hibernate.c
> > @@ -402,7 +402,7 @@ int swsusp_arch_suspend(void)
> >   * Memory allocated by get_safe_page() will be dealt with by the hibernate code,
> >   * we don't need to free it here.
> >   */
> > -int swsusp_arch_resume(void)
> > +int __nocfi swsusp_arch_resume(void)
> >  {
> >       int rc;
> >       void *zero_page;
>
> Why does is the '__nocfi' annotation here rather than on the
> 'hibernate_exit' pointer?
Our first try is to have the callee function(swsusp_arch_suspend_exit)
waived by set __nocfi but failed. It seems like the CFI watched the
caller of function pointer and plant stub code.
>
> Will
Re: [RESEND PATCH] arch: arm64: set __nocfi on swsusp_arch_resume
Posted by Will Deacon 2 weeks, 3 days ago 
On Thu, Jan 22, 2026 at 07:39:34PM +0800, Zhaoyang Huang wrote:
> On Thu, Jan 22, 2026 at 6:32 PM Will Deacon <will@kernel.org> wrote:
> > On Tue, Jan 20, 2026 at 02:06:19PM +0800, zhaoyang.huang wrote:
> > > diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
> > > index 18749e9a6c2d..9717568518ba 100644
> > > --- a/arch/arm64/kernel/hibernate.c
> > > +++ b/arch/arm64/kernel/hibernate.c
> > > @@ -402,7 +402,7 @@ int swsusp_arch_suspend(void)
> > >   * Memory allocated by get_safe_page() will be dealt with by the hibernate code,
> > >   * we don't need to free it here.
> > >   */
> > > -int swsusp_arch_resume(void)
> > > +int __nocfi swsusp_arch_resume(void)
> > >  {
> > >       int rc;
> > >       void *zero_page;
> >
> > Why does is the '__nocfi' annotation here rather than on the
> > 'hibernate_exit' pointer?
> Our first try is to have the callee function(swsusp_arch_suspend_exit)
> waived by set __nocfi but failed. It seems like the CFI watched the
> caller of function pointer and plant stub code.

Thinking about this some more, you're right that the '__nocfi'
annotation has to happen at the call-site, because that's where the
check takes place.

I did start looking at what it would take to emit the CFI type prefix
for swsusp_arch_suspend_exit() using SYM_TYPED_FUNC_START() but it's a
bit grotty having to offset into .hibernate_exit.text when jumping to
the copy and, given that trans_pgd_idmap_page doesn't seem to bother
with BTI at all, your patch looks like the simplest point fix.

I'll ack the resend...

Will

Patchew 2.1-devel-b67e4c2

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