[PATCH 6.18 181/227] arm64: Set __nocfi on swsusp_arch_resume()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>

commit e2f8216ca2d8e61a23cb6ec355616339667e0ba6 upstream.

A DABT is reported[1] on an android based system when resume from hiberate.
This happens because swsusp_arch_suspend_exit() is marked with SYM_CODE_*()
and does not have a CFI hash, but swsusp_arch_resume() will attempt to
verify the CFI hash when calling a copy of swsusp_arch_suspend_exit().

Given that there's an existing requirement that the entrypoint to
swsusp_arch_suspend_exit() is the first byte of the .hibernate_exit.text
section, we cannot fix this by marking swsusp_arch_suspend_exit() with
SYM_FUNC_*(). The simplest fix for now is to disable the CFI check in
swsusp_arch_resume().

Mark swsusp_arch_resume() as __nocfi to disable the CFI check.

[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)

Co-developed-by: Jeson Gao <jeson.gao@unisoc.com>
Signed-off-by: Jeson Gao <jeson.gao@unisoc.com>
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
[catalin.marinas@arm.com: commit log updated by Mark Rutland]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/arm64/kernel/hibernate.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 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;